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Guoqing Zhang

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DOI: 10.1038/nmat2509
2009
Cited 942 times
A dual-emissive-materials design concept enables tumour hypoxia imaging
Luminescent materials are widely used for imaging and sensing owing to their high sensitivity, rapid response and facile detection by many optical technologies. Typically materials must be chemically tailored to achieve intense, photostable fluorescence, oxygen-sensitive phosphorescence or dual emission for ratiometric sensing, often by blending two dyes in a matrix. Dual-emissive materials combining all of these features in one easily tunable molecular platform are desirable, but when fluorescence and phosphorescence originate from the same dye, it can be challenging to vary relative fluorescence/phosphorescence intensities for practical sensing applications. Heavy-atom substitution alone increases phosphorescence by a given, not variable amount. Here, we report a strategy for modulating fluorescence/phosphorescence for a single-component, dual-emissive, iodide-substituted difluoroboron dibenzoylmethane-poly(lactic acid) (BF(2)dbm(I)PLA) solid-state sensor material. This is accomplished through systematic variation of the PLA chain length in controlled solvent-free lactide polymerization combined with heavy-atom substitution. We demonstrate the versatility of this approach by showing that films made from low-molecular-weight BF(2)dbm(I)PLA with weak fluorescence and strong phosphorescence are promising as 'turn on' sensors for aerodynamics applications, and that nanoparticles fabricated from a higher-molecular-weight polymer with balanced fluorescence and phosphorescence intensities serve as ratiometric tumour hypoxia imaging agents.
DOI: 10.1093/nar/gkz333
2019
Cited 658 times
OrthoVenn2: a web server for whole-genome comparison and annotation of orthologous clusters across multiple species
OrthoVenn is a powerful web platform for the comparison and analysis of whole-genome orthologous clusters. Here we present an updated version, OrthoVenn2, which provides new features that facilitate the comparative analysis of orthologous clusters among up to 12 species. Additionally, this update offers improvements to data visualization and interpretation, including an occurrence pattern table for interrogating the overlap of each orthologous group for the queried species. Within the occurrence table, the functional annotations and summaries of the disjunctions and intersections of clusters between the chosen species can be displayed through an interactive Venn diagram. To facilitate a broader range of comparisons, a larger number of species, including vertebrates, metazoa, protists, fungi, plants and bacteria, have been added in OrthoVenn2. Finally, a stand-alone version is available to perform large dataset comparisons and to visualize results locally without limitation of species number. In summary, OrthoVenn2 is an efficient and user-friendly web server freely accessible at https://orthovenn2.bioinfotoolkits.net.
DOI: 10.1039/c2cs35103j
2012
Cited 613 times
Enzyme-responsive polymeric assemblies, nanoparticles and hydrogels
Being responsive and adaptive to external stimuli is an intrinsic feature characteristic of all living organisms and soft matter. Specifically, responsive polymers can exhibit reversible or irreversible changes in chemical structures and/or physical properties in response to a specific signal input such as pH, temperature, ionic strength, light irradiation, mechanical force, electric and magnetic fields, and analyte of interest (e.g., ions, bioactive molecules, etc.) or an integration of them. The past decade has evidenced tremendous growth in the fundamental research of responsive polymers, and accordingly, diverse applications in fields ranging from drug or gene nanocarriers, imaging, diagnostics, smart actuators, adaptive coatings, to self-healing materials have been explored and suggested. Among a variety of external stimuli that have been utilized for the design of novel responsive polymers, enzymes have recently emerged to be a promising triggering motif. Enzyme-catalyzed reactions are highly selective and efficient toward specific substrates under mild conditions. They are involved in all biological and metabolic processes, serving as the prime protagonists in the chemistry of living organisms at a molecular level. The integration of enzyme-catalyzed reactions with responsive polymers can further broaden the design flexibility and scope of applications by endowing the latter with enhanced triggering specificity and selectivity. In this tutorial review, we describe recent developments concerning enzyme-responsive polymeric assemblies, nanoparticles, and hydrogels by highlighting this research area with selected literature reports. Three different types of systems, namely, enzyme-triggered self-assembly and aggregation of synthetic polymers, enzyme-driven disintegration and structural reorganization of polymeric assemblies and nanoparticles, and enzyme-triggered sol-to-gel and gel-to-sol transitions, are described. Their promising applications in drug controlled release, biocatalysis, imaging, sensing, and diagnostics are also discussed.
DOI: 10.1021/ja0720255
2007
Cited 530 times
Multi-Emissive Difluoroboron Dibenzoylmethane Polylactide Exhibiting Intense Fluorescence and Oxygen-Sensitive Room-Temperature Phosphorescence
Boron difluoride compounds are light emitting materials with impressive optical properties. Though their strong one- and two-photon absorption and intense fluorescence are well-known and exploited in molecular probes, lasers, and photosensitizers, phosphorescence, in contrast, is typically observed only at low temperatures. Here, we report that unusual room-temperature phosphorescence is achieved by combining a classic boron dye, difluoroboron dibenzoylmethane, BF2dbm, with poly(lactic acid) (PLA), a common biopolymer, resulting in a highly sensitive single-component oxygen sensor. Fluorescence quantum yields are enhanced, and temperature-sensitive delayed fluorescence is also observed. Multi-emissive BF2dbmPLA biomaterials show great promise as multifunctional molecular probes and sensors.
DOI: 10.1016/j.apm.2012.09.039
2013
Cited 358 times
A multi-objective facility location model for closed-loop supply chain network under uncertain demand and return
A closed-loop supply chain (CLSC) network consists of both forward and reverse supply chains. In this paper, a CLSC network is investigated which includes multiple plants, collection centres, demand markets, and products. To this aim, a mixed-integer linear programming model is proposed that minimizes the total cost. Besides, two test problems are examined. The model is extended to consider environmental factors by weighed sums and ε-constraint methods. In addition, we investigate the impact of demand and return uncertainties on the network configuration by stochastic programming (scenario-based). Computational results show that the model can handle demand and return uncertainties, simultaneously.
DOI: 10.1002/anie.201601252
2016
Cited 346 times
Versatile Room‐Temperature‐Phosphorescent Materials Prepared from N‐Substituted Naphthalimides: Emission Enhancement and Chemical Conjugation
Abstract Purely organic materials with room‐temperature phosphorescence (RTP) are currently under intense investigation because of their potential applications in sensing, imaging, and displaying. Inspired by certain organometallic systems, where ligand‐localized phosphorescence ( 3 π‐π*) is mediated by ligand‐to‐metal or metal‐to‐ligand charge transfer (CT) states, we now show that donor‐to‐acceptor CT states from the same organic molecule can also mediate π‐localized RTP. In the model system of N‐substituted naphthalimides (NNIs), the relatively large energy gap between the NNI‐localized 1 π‐π* and 3 π‐π* states of the aromatic ring can be bridged by intramolecular CT states when the NNI is chemically modified with an electron donor. These NNI‐based RTP materials can be easily conjugated to both synthetic and natural macromolecules, which can be used for RTP microscopy.
DOI: 10.1002/adma.201702428
2017
Cited 338 times
Conjugated Microporous Polymer Nanosheets for Overall Water Splitting Using Visible Light
Direct water splitting into H2 and O2 using photocatalysts by harnessing sunlight is very appealing to produce storable chemical fuels. Conjugated polymers, which have tunable molecular structures and optoelectronic properties, are promising alternatives to inorganic semiconductors for water splitting. Unfortunately, conjugated polymers that are able to efficiently split pure water under visible light (400 nm) via a four-electron pathway have not been previously reported. This study demonstrates that 1,3-diyne-linked conjugated microporous polymer nanosheets (CMPNs) prepared by oxidative coupling of terminal alkynes such as 1,3,5-tris-(4-ethynylphenyl)-benzene (TEPB) and 1,3,5-triethynylbenzene (TEB) can act as highly efficient photocatalysts for splitting pure water (pH ≈ 7) into stoichiometric amounts of H2 and O2 under visible light. The apparent quantum efficiencies at 420 nm are 10.3% and 7.6% for CMPNs synthesized from TEPB and TEB, respectively; the measured solar-to-hydrogen conversion efficiency using the full solar spectrum can reach 0.6%, surpassing photosynthetic plants in converting solar energy to biomass (globally average ≈0.10%). First-principles calculations reveal that photocatalytic H2 and O2 evolution reactions are energetically feasible for CMPNs under visible light irradiation. The findings suggest that organic polymers hold great potential for stable and scalable solar-fuel generation.
DOI: 10.1016/j.enconman.2017.02.022
2017
Cited 334 times
Experimental investigation on the thermal performance of heat pipe-assisted phase change material based battery thermal management system
In this paper, a heat pipe-assisted phase change material (PCM) based battery thermal management (BTM) system is designed to fulfill the comprehensive energy utilization for electric vehicles and hybrid electric vehicles. Combining the large heat storage capacity of the PCM with the excellent cooling effect of heat pipe, the as-constructed heat pipe-assisted PCM based BTM is feasible and effective with a relatively longer operation time and more suitable temperature. The experimental results show that the temperature maldistribution of battery module can be influenced by heat pipes when they are activated under high discharge rates of the batteries. Moreover, with forced air convection, the highest temperature could be controlled below 50 °C even under the highest discharge rate of 5C and a more stable and lower temperature fluctuation is obtained under cycling conditions. Meanwhile, the effectiveness of further increasing air velocity (i.e., more fan power consumption) is limited when the highest temperature continues to reduce at a lower rate due to the phase transition process of PCM. These results are expected to provide insights into the design and optimization of BTM systems.
DOI: 10.1016/j.gloplacha.2015.05.013
2015
Cited 270 times
An inventory of glacial lakes in the Third Pole region and their changes in response to global warming
No glacial lake census exists for the Third Pole region, which includes the Pamir-Hindu Kush-Karakoram-Himalayas and the Tibetan Plateau. Therefore, comprehensive information is lacking about the distribution of and changes in glacial lakes caused by current global warming conditions. In this study, the first glacial lake inventories for the Third Pole were conducted for ~ 1990, 2000, and 2010 using Landsat TM/ETM + data. Glacial lake spatial distributions, corresponding areas and temporal changes were examined. The significant results are as follows. (1) There were 4602, 4981, and 5701 glacial lakes (> 0.003 km2) covering areas of 553.9 ± 90, 581.2 ± 97, and 682.4 ± 110 km2 in ~ 1990, 2000, and 2010, respectively; these lakes are primarily located in the Brahmaputra (39%), Indus (28%), and Amu Darya (10%) basins. (2) Small lakes (< 0.2 km2) are more sensitive to climate changes. (3) Lakes closer to glaciers and at higher altitudes, particularly those connected to glacier termini, have undergone larger area changes. (4) Glacier-fed lakes are dominant in both quantity and area (> 70%) and exhibit faster expansion trends overall compared to non-glacier-fed lakes. We conclude that glacier meltwater may play a dominant role in the areal expansion of most glacial lakes in the Third Pole. In addition, the patterns of the glacier-fed lakes correspond well with warming temperature trends and negative glacier mass balance patterns. This paper presents an important database of glacial lakes and provides a basis for long-term monitoring and evaluation of outburst flood disasters primarily caused by glacial lakes in the Third Pole.
DOI: 10.1016/j.eswa.2011.12.056
2012
Cited 266 times
An integrated model for closed-loop supply chain configuration and supplier selection: Multi-objective approach
Reverse logistics consists of all operations related to the reuse of products. External suppliers are one of the important members of reverse logistics and closed loop supply chain (CLSC) networks. However in CLSC network configuration models, suppliers are assessed based on purchasing cost and other factors such as on-time delivery are ignored. In this research, a general closed loop supply chain network is examined that includes manufacturer, disassembly, refurbishing, and disposal sites. Meanwhile, it is managed by the manufacturer. We propose an integrated model which has two phases. In the first phase, a framework for supplier selection criteria in RL is proposed. Besides, a fuzzy method is designed to evaluate suppliers based on qualitative criteria. The output of this stage is the weight of each supplier according to each part. In the second phase, we propose a multi objective mixed-integer linear programming model to determine which suppliers and refurbishing sites should be selected (strategic decisions), and find out the optimal number of parts and products in CLSC network (tactical decisions). The objective functions maximize profit and weights of suppliers, and one of them minimizes defect rates. To our knowledge, this model is the first effort to consider supplier selection, order allocation, and CLSC network configuration, simultaneously. The mathematical programming model is validated through numerical analysis.
DOI: 10.1038/s41566-020-00744-0
2021
Cited 253 times
Organic phosphors with bright triplet excitons for efficient X-ray-excited luminescence
Materials that exhibit X-ray-excited luminescence have great potential in radiation detection, security inspection, biomedical applications and X-ray astronomy1–5. However, high-performance materials are almost exclusively limited to ceramic scintillators, which are typically prepared under high temperatures6. Herein we report metal-free organic phosphors based on a molecular design that supports efficient triplet exciton harvesting to enhance radioluminescence. These organic scintillators exhibit a detection limit of 33 nGy s–1, which is 167 times lower than the standard dosage for X-ray medical examination and we demonstrate their potential application in X-ray radiography. These findings provide a fundamental design principle and new route for the creation of promising alternatives to incumbent inorganic scintillators. Furthermore, they offer new opportunities for development of flexible, stretchable X-ray detectors and imagers for non-destructive radiography testing and medical imaging. Organic, metal-free materials that act as efficient X-ray scintillators could bring new opportunities for X-ray imaging.
DOI: 10.1016/j.enconman.2011.07.009
2011
Cited 247 times
Simulation and experiment of thermal energy management with phase change material for ageing LiFePO4 power battery
Thermal energy management performance of ageing commercial rectangular LiFePO4 power batteries using phase change material (PCM) and thermal behavior related to thermal conductivity between the PCM and the cell are discussed in this paper. The heat sources are simplified according to the experimental results of the cells discharged at 35 A (≈5 C). 3-D modules of a single cell and battery pack are formulated, respectively. The results show that the thermal resistance in the cell leads to an inevitable temperature difference. It is necessary to improve the thermal conductivity and to lower the melting point of the PCM for heat transfer enhancement. The PCM with a melting point lower than 45 °C will be more effective for heat dissipation, with a desired maximum temperature below 50 °C. The temperature difference in the whole unit before PCM melting will be decreased significantly. In addition, a proper kPCM:kc is necessary for a well designed battery thermal energy management system.
DOI: 10.1109/tii.2019.2949007
2020
Cited 242 times
Trajectory Tracking Control of AUVs via Adaptive Fast Nonsingular Integral Terminal Sliding Mode Control
This article aims to develop an effective control method that can improve the convergence rate over the existing adaptive nonsingular integral terminal sliding mode control (ANITSMC) method for the trajectory tracking control of autonomous underwater vehicles (AUVs). To achieve this goal, an adaptive fast nonsingular integral terminal sliding mode control (AFNITSMC) method is proposed. First, considering that the existing nonsingular integral terminal sliding mode (NITSM) has slow convergence rate in the region far from the equilibrium point, a fast NITSM (FNITSM) is proposed, which guarantees fast transient convergence both at a distance from and at a close range of the equilibrium point, and therefore increases the convergence rate over the existing NITSM. Then, using this FNITSM and adaptive technique, an AFNITSMC method is designed for AUVs. It yields local finite-time convergence of the velocity tracking errors to zero and then local exponential convergence of the position tracking errors to zero, without requiring any a priori knowledge of the upper bounds of the uncertainties and disturbances. Compared with the existing ANITSMC method, the salient feature of the proposed AFNITSMC method is that it provides AUV dynamics a faster convergence rate. Finally, simulation results demonstrate the efficiency of the proposed AFNITSMC method and its superiority over the existing ANITSMC method.
DOI: 10.1016/j.cor.2010.08.008
2011
Cited 241 times
Optimal production planning for a multi-product closed loop system with uncertain demand and return
We study the production planning problem for a multi-product closed loop system, in which the manufacturer has two channels for supplying products: producing brand-new products and remanufacturing returns into as-new ones. In the remanufacturing process, used products are bought back and remanufactured into as-new products which are sold together with the brand-new ones. The demands for all the products are uncertain, and their returns are uncertain and price-sensitive. The problem is to maximize the manufacturer's expected profit by jointly determining the production quantities of brand-new products, the quantities of remanufactured products and the acquisition prices of the used products, subject to a capacity constraint. A mathematical model is presented to formulate the problem and a Lagrangian relaxation based approach is developed to solve the problem. Numerical examples are presented to illustrate the model and test the solution approach. Computational results show that the proposed approach is highly promising for solving the problems. The sensitivity analysis is also conducted to generate managerial insights.
DOI: 10.1038/s41467-019-13048-x
2019
Cited 232 times
Ultralong UV/mechano-excited room temperature phosphorescence from purely organic cluster excitons
Abstract Purely organic room temperature phosphorescence (RTP) has attracted wide attention recently due to its various application potentials. However, ultralong RTP (URTP) with high efficiency is still rarely achieved. Herein, by dissolving 1,8-naphthalic anhydride in certain organic solid hosts, URTP with a lifetime of over 600 ms and overall quantum yield of over 20% is realized. Meanwhile, the URTP can also be achieved by mechanical excitation when the host is mechanoluminescent. Femtosecond transient absorption studies reveal that intersystem crossing of the host is accelerated substantially in the presence of a trace amount of 1,8-naphthalic anhydride. Accordingly, we propose that a cluster exciton spanning the host and guest forms as a transient state before the guest acts as an energy trap for the RTP state. The cluster exciton model proposed here is expected to help expand the varieties of purely organic URTP materials based on an advanced understanding of guest/host combinations.
DOI: 10.1039/c5ta03455h
2015
Cited 212 times
Hierarchical NiCo<sub>2</sub>O<sub>4</sub>@NiMoO<sub>4</sub> core–shell hybrid nanowire/nanosheet arrays for high-performance pseudocapacitors
Hierarchical NiCo<sub>2</sub>O<sub>4</sub>@NiMoO<sub>4</sub> core–shell nanowire/nanosheet arrays were successfully fabricated and assembled in an asymmetric supercapacitor device with outstanding electrochemical performance.
DOI: 10.1016/j.applthermaleng.2018.06.048
2018
Cited 199 times
Experimental investigation of the thermal performance of heat pipe assisted phase change material for battery thermal management system
In this study, a serials phase change materials (PCM) based battery thermal management systems for cylindrical lithium battery module were designed, which were pure PCM, heat pipe coupled with air assisted PCM (PCM/HP-Air), heat pipe coupled with liquid assisted PCM (PCM/HP-Liquid), respectively. The PCM with large heat storage capacity and heat pipe coupled with liquid cooling exhibit excellent thermal performance for battery module, which is an effective and reliable method with relative longer working time and appropriate temperature. The results by experiments at different discharge rates indicated that heat pipe played an important role in transporting the heat promptly and balancing the temperature uniformly for PCM based battery module. What’s more, the heat pipe coupled with liquid cooling presented a remarkable controlling temperature capacity, the highest temperature could be maintained at 50 °C during 3 C discharge rate. Meanwhile, a lower temperature difference of the PCM/HP-Liquid than the other two modules was obtained by nearly 3 °C, which displayed a prominent balancing temperature effectiveness. It could be concluded that the above results can provide perspectives in designing and optimizing battery thermal management system.
DOI: 10.1016/j.biomaterials.2013.09.089
2014
Cited 181 times
Biodegradable self-assembled nanoparticles of poly (d,l-lactide-co-glycolide)/hyaluronic acid block copolymers for target delivery of docetaxel to breast cancer
To develop biodegradable docetaxel-loaded self-assembled nanoparticles of poly (d,l-lactide-co-glycolide)/hyaluronic acid block copolymers were successfully synthesized. These copolymers could form nanoparticles with small size (<200 nm), an acceptable CMC (∼7.9 mg/L), typical core/shell structure and superior stability in one week. DTX-loaded PLGA502H-b-HA5.6k nanoparticles (DTX/SANPs) showed a biphasic release pattern within 120 h, and exhibited enhanced cytotoxicity toward CD44-overexpressing MDA-MB-231 cells. Cellular uptake study indicated that PLGA502H-b-HA5.6k nanoparticles (SANPs) were taken up in MDA-MB-231 cells by CD44-mediated endocytosis. Pharmacokinetics study revealed DTX/SANPs could prolong the circulation of DTX in the blood. In vivo studies demonstrated that SANPs exhibited enhanced tumor targeting and antitumor activity with lower systemic toxicity. In conclusion, DTX/SANPs have great potential for targeted chemotherapy for CD44-overexpressing breast cancer.
DOI: 10.1002/adma.201904273
2019
Cited 180 times
Aggregation‐Induced Dual‐Phosphorescence from Organic Molecules for Nondoped Light‐Emitting Diodes
Abstract Aggregation‐induced emission (AIE) is a beneficial strategy for generating highly effective solid‐state molecular luminescence without suffering losses in quantum yield. However, the majority of reported AIE‐active molecules exhibit only strong fluorescence, which is not ideal for electrical excitation in organic light‐emitting diodes (OLEDs). By introducing various substituent groups onto the biscarbazole compound, a series of molecular materials with aggregation‐induced phosphorescence (AIP) is designed, which exhibits two distinctly different phosphorescence bands and an absolute solid‐state room‐temperature phosphorescence quantum yield up to 64%. Taking advantage of the AIE feature, the AIP molecules are fabricated into OLEDs as a homogeneous light‐emitting layer, which allows for relatively small efficiency roll‐off and shows an external electroluminescence quantum yield of up to 5.8%, more than the theoretical limit for purely fluorescent OLED devices. The design showcases a promising strategy for the production of cost‐effective and highly efficient OLED technology.
DOI: 10.1093/nar/gkaa1022
2020
Cited 166 times
Database Resources of the National Genomics Data Center, China National Center for Bioinformation in 2021
The National Genomics Data Center (NGDC), part of the China National Center for Bioinformation (CNCB), provides a suite of database resources to support worldwide research activities in both academia and industry. With the explosive growth of multi-omics data, CNCB-NGDC is continually expanding, updating and enriching its core database resources through big data deposition, integration and translation. In the past year, considerable efforts have been devoted to 2019nCoVR, a newly established resource providing a global landscape of SARS-CoV-2 genomic sequences, variants, and haplotypes, as well as Aging Atlas, BrainBase, GTDB (Glycosyltransferases Database), LncExpDB, and TransCirc (Translation potential for circular RNAs). Meanwhile, a series of resources have been updated and improved, including BioProject, BioSample, GWH (Genome Warehouse), GVM (Genome Variation Map), GEN (Gene Expression Nebulas) as well as several biodiversity and plant resources. Particularly, BIG Search, a scalable, one-stop, cross-database search engine, has been significantly updated by providing easy access to a large number of internal and external biological resources from CNCB-NGDC, our partners, EBI and NCBI. All of these resources along with their services are publicly accessible at https://bigd.big.ac.cn.
DOI: 10.1016/j.jpowsour.2020.228398
2020
Cited 160 times
A novel thermal management structure using serpentine phase change material coupled with forced air convection for cylindrical battery modules
The temperature control technology based on phase change material (PCM) demonstrates excellent performance in the field of battery thermal management. However, the compact and bulky structure of the traditional composite PCM (CPCM) module reduces the energy density of the battery pack greatly, and is unfavorable to the secondary heat dissipation. In this work, we develop a novel PCM cooling structure by substituting the common block-shaped CPCM (B-CPCM) module with serpentine CPCM (S-CPCM) plates. The S-CPCM plates with high shape stability provide a much larger surface area and many air flow channels in comparison to the B-CPCM module, thus endowing the module with outstanding secondary heat dissipation capability. For example, under the same fan power of forced air convection (5.2 W), the S-CPCM module delivers a much lower maximum temperature than the B-CPCM module (51.9 vs. 54.2 °C) during the repeated charge-discharge process. As highlighted here, on the basis of guaranteeing the cooling performance, the S-CPCM cooling structure also saves ~70% of the CPCM amount, and thereby the energy density of the battery module is increased by 13.8 Wh kg−1.
DOI: 10.1039/c6nr03656b
2016
Cited 154 times
Aggregation-induced intersystem crossing: a novel strategy for efficient molecular phosphorescence
“Aggregation-caused quenching” (ACQ) and “aggregation-induced emission” (AIE) are two well-known mechanisms for polymer luminescence. Here we proposed an alternative mechanism termed “aggregation-induced intersystem crossing” (AI-ISC). By aggregating certain fluorescent dye molecules, one can improve the energy matches between excited singlet and triplet states so as to promote the intersystem crossing (ISC) rate, and consequently prolong the lifetime of excited electrons by steering them into triplet states. First-principles calculations suggested that the enhanced ISC rate could substantially promote molecular phosphorescence in aggregated systems of originally fluorescent dye molecules, as later validated by experimental measurement. Meanwhile, the emission spectra experience a red shift along with the aggregation, providing a convenient knob to tune the phosphorescence wavelength. The proposed AI-ISC mechanism may open up a new design approach for the emerging luminescent material applications.
DOI: 10.1002/er.3801
2017
Cited 151 times
Liquid cooling based on thermal silica plate for battery thermal management system
To achieve safe, long lifetime, and high-performance lithium-ion batteries, a battery thermal management system (BTMS) is indispensable. This is especially required for enabling fast charging-discharging and in aggressive operating conditions. In this research, a new type of battery cooling system based on thermal silica plates has been designed for prismatic lithium-ion batteries. Experimental and simulations are combined to investigate the cooling capability of the BTMS associated to different number of cooling channels, flow rates, and flow directions while at different discharge C-rates. Results show that the maximum temperature reached within the battery decreases as the amount of thermal silica plates and liquid channels increases. The flow direction had no significant influence on the cooling capability. While the performance obviously improves with the increase in inlet flow rate, after a certain threshold, the gain reduces strongly so that it does not anymore justify the higher energy cost. Discharged at 3 C-rate, an inlet flow rate of 0.1 m/s was sufficient to efficiently cool down the system; discharged at 5 C-rate, the optimum inlet flow rate was 0.25 m/s. Simulations could accurately reproduce experimental results, allowing for an efficient design of the liquid-cooled BTMS.
DOI: 10.1016/j.enconman.2018.02.061
2018
Cited 149 times
A novel nanosilica-enhanced phase change material with anti-leakage and anti-volume-changes properties for battery thermal management
As an advanced battery thermal management method, phase change material (PCM) cooling technology is highly desirable but remains significant challenges, considering the instability of the PCM module, including PCM leakage, volume changes and inhomogeneity of the whole module during the repeated melting/solidifying processes. Herein, we develop a kind of nanosilica (NS)-enhanced composite PCM (CPCM-NS) with outstanding anti-leakage and anti-volume-change performances for power battery thermal management. The NS presents numerous nanoscale pores ranging from 30 to 100 nm, which can adsorb liquid phase paraffin (PA) intensively, thus preventing the migration and leakage of liquid PA, increasing the homogeneity and reliving the volume change phenomenon of the module to a great extent. As a result, these enhanced properties of CPCM-NS endow the obtained battery module with much better cooling efficiency and durability. For instance, the maximum temperatures of CPCM-NS with 5.5 wt% of NS are 1.6, 2.4, 4.5, 5.3 and 5.9 °C lower than those of CPCM without NS at the 1st, 2nd, 4th, 6th and 8th cycle charge/discharge cycle, respectively, and this temperature difference remains stable at 6.22 ± 0.05 °C during the subsequent cycles.
DOI: 10.1016/j.applthermaleng.2018.11.100
2019
Cited 147 times
A phase change material with enhanced thermal conductivity and secondary heat dissipation capability by introducing a binary thermal conductive skeleton for battery thermal management
In order to enhance the thermal conductivity and secondary heat dissipation capability of the phase change material (PCM) in battery thermal management (BTM) applications, a new kind of composite PCM (CPCM) is successfully prepared by constructing a binary thermal conductive skeleton of expanded graphite (EG)/copper foam (CF). The EG with porous structure can adsorb the PCM of paraffin and act as a micro-thermal-conductive framework to transfer the heat to the adjacent CF skeleton. The CF acts as a macro-skeleton to transfer the heat throughout the CPCM plate and enhance the heat transfer coefficient of the interface between the CPCM plate and air. In consequence, the obtained CPCM-based battery pack with EG/CF (CPCM-EG/CF) delivers much better cooling and temperature-uniformed performances than those without EG/CF or CF, especially under a secondary heat dissipation system of forced air convection. For example, the CPCM-EG/CF pack shows stable and lowest maximum temperature and temperature difference of 48.0 and 3.9 °C during the cycling charge-discharge tests under forced air flow, respectively.
DOI: 10.1016/j.applthermaleng.2020.116151
2021
Cited 144 times
Thermal management of Lithium-ion battery pack through the application of flexible form-stable composite phase change materials
Phase change materials (PCM) have become a research interest in the area of passive heat dissipation owing to many advantages, such as simple structure, high latent heat, low cost and so on. However, due to their low thermal conductivity, easy leakage, and poor mechanical properties, PCM have limited application, especially in battery thermal management. In this study, a novel flexible composite [email protected]/EG is successfully prepared by dissolving in an organic solvent and utilized in battery thermal management (BTM) system. Here, styrene butadiene styrene (SBS) as a supporting material, paraffin (PA) as a phase change material and expanded graphite (EG) as a thermal conductivity enhancer. The chemical properties and structure of the composite PCM are analyzed by X-ray diffractometer, scanning electron microscope and thermal conductivity measurements, moreover, the stability is analyzed through measuring the tensile/bending strength. Besides, the relationship between the maximum temperature and temperature difference with state of charge for battery module are analyzed. During the 5 C discharge process, the maximum temperature of the battery module can be maintained below 46 °C and the temperature difference be controlled within 4 °C. Thus, it should be concluded that flexible form-stable composite [email protected]/EG can be applied well in BTM system and more extensive thermal management systems.
DOI: 10.1002/anie.202106204
2021
Cited 130 times
An Organic Host–Guest System Producing Room‐Temperature Phosphorescence at the Parts‐Per‐Billion Level
Abstract Manipulation of long‐lived triplet excitons in organic molecules is key to applications including next‐generation optoelectronics, background‐free bioimaging, information encryption, and photodynamic therapy. However, for organic room‐temperature phosphorescence (RTP), which stems from triplet excitons, it is still difficult to simultaneously achieve efficiency and lifetime enhancement on account of weak spin–orbit coupling and rapid nonradiative transitions, especially in the red and near‐infrared region. Herein, we report that a series of fluorescent naphthalimides—which did not originally show observable phosphorescence in solution, as aggregates, in polymer films, or in any other tested host material, including heavy‐atom matrices at cryogenic temperatures—can now efficiently produce ultralong RTP ( ϕ =0.17, τ=243 ms) in phthalimide hosts. Notably, red RTP (λ RTP =628 nm) is realized at a molar ratio of less than 10 parts per billion, demonstrating an unprecedentedly low guest‐to‐host ratio where efficient RTP can take place in molecular solids.
DOI: 10.1016/j.ijheatmasstransfer.2019.04.050
2019
Cited 129 times
Optimization of the detailed factors in a phase-change-material module for battery thermal management
Phase change material (PCM) cooling, as an excellent option for ensuring safety via balancing heat distribution, has been widely used in the thermal management of lithium-ion battery. In this work, a simple PCM cooling structure has been designed. Then we systematically investigate its cooling behavior and the influence of several detailed factors on the performance, including the thickness and phase change temperature (PCT) of the PCM, as well as the laying-aside time during dynamic cycling. The experimental results show that a PCM module with a thickness of ∼10 mm presents the optimal cooling performance, consistent with the theoretical calculation, but the lower heat dissipation capability at the bottom of the battery should be taken into account when designing the PCM module. In addition, increasing the laying-aside time is also beneficial to enhancing the cooling efficiency, whereas the selection of the PCT is variable based on different specific applications and comprehensive requirements, particularly those targeting guaranteeing a higher capacity of the batteries.
DOI: 10.1016/j.ejor.2020.05.014
2020
Cited 128 times
Manufacturer vs. Consumer Subsidy with Green Technology Investment and Environmental Concern
This paper analyzes the effect of environmental subsidies on the incentives of investing in emission-reducing technologies in manufacturing amid the environmental concerns of consumers. The study adopts a game theoretical approach with respect to the interactions of environmental subsidy policies, emissions abatement and other decisions between the government and manufacturer(s). We examine and compare two environmental subsidy policies, namely, consumer and manufacturer subsidies, and find that the former yields a lower abatement and higher consumption quantity than the latter by focusing on consumption quantity instead of production emissions abatement. The manufacturer takes advantage of the consumer subsidy to increase its profits by increasing its production quantity and setting a high price simultaneously. We also show that the manufacturer's practice of taking advantage of the consumer subsidy presents a higher financial burden for the government than under the manufacturer subsidy. Besides, the consumer subsidy results in higher net emissions than the manufacturer subsidy due to the larger production quantity and lower abatement level under this policy. Despite the result of higher emissions, the consumer subsidy generates a higher social welfare compared to the manufacturer subsidy given that the former can lead to a larger quantity supply and profit for the manufacturer. We also extend the base model to multiple other cases to check the robustness of our results and find that our main results still hold qualitatively in these extensions.
DOI: 10.1016/j.apsb.2020.10.002
2021
Cited 126 times
Identifying potential anti-COVID-19 pharmacological components of traditional Chinese medicine Lianhuaqingwen capsule based on human exposure and ACE2 biochromatography screening
Lianhuaqingwen (LHQW) capsule, a herb medicine product, has been clinically proved to be effective in coronavirus disease 2019 (COVID-19) pneumonia treatment. However, human exposure to LHQW components and their pharmacological effects remain largely unknown. Hence, this study aimed to determine human exposure to LHQW components and their anti-COVID-19 pharmacological activities. Analysis of LHQW component profiles in human plasma and urine after repeated therapeutic dosing was conducted using a combination of HRMS and an untargeted data-mining approach, leading to detection of 132 LHQW prototype and metabolite components, which were absorbed via the gastrointestinal tract and formed via biotransformation in human, respectively. Together with data from screening by comprehensive 2D angiotensin-converting enzyme 2 (ACE2) biochromatography, 8 components in LHQW that were exposed to human and had potential ACE2 targeting ability were identified for further pharmacodynamic evaluation. Results show that rhein, forsythoside A, forsythoside I, neochlorogenic acid and its isomers exhibited high inhibitory effect on ACE2. For the first time, this study provides chemical and biochemical evidence for exploring molecular mechanisms of therapeutic effects of LHQW capsule for the treatment of COVID-19 patients based on the components exposed to human. It also demonstrates the utility of the human exposure-based approach to identify pharmaceutically active components in Chinese herb medicines.
DOI: 10.1016/j.ymssp.2020.107212
2021
Cited 124 times
A hybrid piezo-dielectric wind energy harvester for high-performance vortex-induced vibration energy harvesting
This paper proposes a novel hybrid piezo-dielectric (PD) wind energy harvester, to efficiently harvest the vortex-induced vibration (VIV) energy from low-speed wind. The hybrid PD harvester brings together the following two electromechanical transduction mechanisms: piezoelectric ceramic (PZT) sheets and a vibro-impact (VI) dielectric elastomer generator (DEG). The PZT sheets directly transduce the beam’s vibration into electricity, whereas the VI DEG transduces the impacts between the inner ball and the dielectric elastomer membranes resulting from the bluff body’s vibration into electricity. The theoretical model of the hybrid PD harvester subjected to VIV is formulated. Wind tunnel experiments are performed to validate the aerodynamic part of the theoretical model and identify the aerodynamic coefficients. Afterward, based on the theoretical model, the numerical investigation of the hybrid PD harvester is conducted, which uncovers the insights of the conjunction of the PZT and VI DEG for VIV energy harvesting enhancement. It is seen that in the lock-in region of the VIV, where both the PZT and VI DEG can effectively harvest the VIV energy, the VI DEG can generate much higher power. This demonstrates the superiority of the hybrid PD harvester. Parametrical studies show that the smaller mass, higher stiffness and larger diameter of the bluff body are beneficial designs, which broadens the working wind range and enhances the generate power.
DOI: 10.1093/nar/gkac1073
2022
Cited 122 times
Database Resources of the National Genomics Data Center, China National Center for Bioinformation in 2023
The National Genomics Data Center (NGDC), part of the China National Center for Bioinformation (CNCB), provides a family of database resources to support global academic and industrial communities. With the explosive accumulation of multi-omics data generated at an unprecedented rate, CNCB-NGDC constantly expands and updates core database resources by big data archive, integrative analysis and value-added curation. In the past year, efforts have been devoted to integrating multiple omics data, synthesizing the growing knowledge, developing new resources and upgrading a set of major resources. Particularly, several database resources are newly developed for infectious diseases and microbiology (MPoxVR, KGCoV, ProPan), cancer-trait association (ASCancer Atlas, TWAS Atlas, Brain Catalog, CCAS) as well as tropical plants (TCOD). Importantly, given the global health threat caused by monkeypox virus and SARS-CoV-2, CNCB-NGDC has newly constructed the monkeypox virus resource, along with frequent updates of SARS-CoV-2 genome sequences, variants as well as haplotypes. All the resources and services are publicly accessible at https://ngdc.cncb.ac.cn.
DOI: 10.1016/j.enconman.2019.112319
2020
Cited 121 times
Characterization and experimental investigation of aluminum nitride-based composite phase change materials for battery thermal management
Thermal management plays an important role in battery modules, especially under extreme operating conditions. Phase change materials (PCMs)-based cooling has been recognized as a promising approach that can prolong the life span of batteries and endure the passive thermal accumulation in the module. In this study, various mass fractions (0 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%, and 25 wt%) of aluminum nitride (AlN) were added to composite PCMs to serve as heat-transfer promoters. The effect of the AlN additives on the thermal conductivity, mechanical properties, and volume resistivity were analyzed, and the root causes originating from the morphologies and structures of the composite PCMs were further examined. The results indicated that adding 20 wt% of the AlN in the composite PCMs was an optimal strategy. In addition, an AlN/paraffin (PA)/expanded graphite (EG)/epoxy resin composite PCMs-based 18650 LiFePO4 battery module was designed for thermal management. This battery module exhibited much better heat dissipation and temperature uniformity than an air-cooled battery module, leading to a 19.4% decrease of the maximum temperature and a less than 1 °C temperature difference at a high discharge rate of 3C. Thus, it could be concluded that the AlN-enhanced composite PCMs thermal management system exhibited a prominent controlling temperature and balancing temperature capacity for the battery module.
DOI: 10.1016/j.cej.2021.131116
2022
Cited 120 times
Composite phase change material with room-temperature-flexibility for battery thermal management
Flexible composite phase change materials (CPCMs) can minimize the thermal contact resistance in battery thermal management. However, these “thermally-induced” flexible CPCMs only present well-flexibility above the phase change temperature, which is unfavorable to the flexible assembly of the cells and battery modules with variable specifications. Herein, a kind of flexible CPCM with well-retained flexibility in a wide temperature range is prepared by carefully selecting a copolyester thermoplastic elastomer with polyether soft segment (TPC-et) to replace the conventional olefin block copolymer (OBC) skeleton. The internal rotation resistance of the ether bond in TPC-et is much lower than that of the C–C bond in OBC, thus giving rise to a better flexibility in room and low temperatures from 20 to −5 ℃. Combining the room-temperature-flexibility with the high thermal conductivity of 1.64 W m−1 K−1, enough latent heat of 102 J g−1 and suitable phase change region of 40–50 ℃, the obtained TPC-et based flexible CPCM shows outstanding applicability and cooling performance to various cells and battery modules through facile installations. The maximum temperature of the cylindrical, prismatic and pouch battery modules with TPC-et based CPCM is 51.5, 42.1 and 50.0 ℃, respectively, 4.0, 3.9 and 5.4 ℃ lower than the modules using rigid CPCM, respectively.
DOI: 10.1016/j.applthermaleng.2019.114698
2020
Cited 114 times
Optimization of the internal fin in a phase-change-material module for battery thermal management
As an excellent option that has wide application in the thermal management system to ensure the safety of lithium-ion batteries, phase change material (PCM) cooling technology is highly desirable but the low thermal conductivity of PCMs limits its application. Herein, a series of experiments are conducted with and without fins to investigate the effects of fin configurations. The experimental results show that longitudinal fins are beneficial for dissipating the accumulated heat at the bottom and air convection with the ambient, while circular fins present better heat conduction due to their larger surface area. Regarding the fin number, in a limited-space module, increasing fins does not necessary mean an increase in fin efficiency, while the use of four longitudinal fins displays the highest efficiency for 18650-battery module in the current work, resulting a temperature drop from 36.9 to 34.2 °C in the rectangular finned module. Finally, based on these conclusions, an optimized PCM module combining various fins is designed and tested for its thermal performance, where a greater balance between the heat absorption and heat dissipation is obtained with lower maximum battery temperature and smaller temperature range. The Tmax in the optimized finned module is 29.1 °C at 1 C charging rate, decreasing by 5.5%, in comparison to that of the rectangular-finned module. Such an experimental study can not only provide new references for the experimental data in the practical battery module but also broaden minds on the design for PCM-based finned modules.
DOI: 10.1016/j.phymed.2020.153315
2021
Cited 109 times
Systems pharmacological study illustrates the immune regulation, anti-infection, anti-inflammation, and multi-organ protection mechanism of Qing-Fei-Pai-Du decoction in the treatment of COVID-19
The traditional Chinese medicine (TCM) formula Qing-Fei-Pai-Du decoction (QFPDD) was the most widely used prescription in China's campaign to contain COVID-19, which has exhibited positive effects. However, the underlying mode of action is largely unknown.A systems pharmacology strategy was proposed to investigate the mechanisms of QFPDD against COVID-19 from molecule, pathway and network levels.The systems pharmacological approach consisted of text mining, target prediction, data integration, network study, bioinformatics analysis, molecular docking, and pharmacological validation. Especially, we proposed a scoring method to measure the confidence of targets identified by prediction and text mining, while a novel scheme was used to identify important targets from 4 aspects.623 high-confidence targets of QFPDD's 12 active compounds were identified, 88 of which were overlapped with genes affected by SARS-CoV-2 infection. These targets were found to be involved in biological processes related with the development of COVID-19, such as pattern recognition receptor signaling, interleukin signaling, cell growth and death, hemostasis, and injuries of the nervous, sensory, circulatory, and digestive systems. Comprehensive network and pathway analysis were used to identify 55 important targets, which regulated 5 functional modules corresponding to QFPDD's effects in immune regulation, anti-infection, anti-inflammation, and multi-organ protection, respectively. Four compounds (baicalin, glycyrrhizic acid, hesperidin, and hyperoside) and 7 targets (AKT1, TNF-α, IL6, PTGS2, HMOX1, IL10, and TP53) were key molecules related to QFPDD's effects. Molecular docking verified that QFPDD's compounds may bind to 6 host proteins that interact with SARS-CoV-2 proteins, further supported the anti-virus effect of QFPDD. At last, in intro experiments validated QFPDD's important effects, including the inhibition of IL6, CCL2, TNF-α, NF-κB, PTGS1/2, CYP1A1, CYP3A4 activity, the up-regulation of IL10 expression, and repressing platelet aggregation.This work illustrated that QFPDD could exhibit immune regulation, anti-infection, anti-inflammation, and multi-organ protection. It may strengthen the understanding of QFPDD and facilitate more application of this formula in the campaign to SARS-CoV-2.
DOI: 10.1016/j.rser.2022.112207
2022
Cited 106 times
Advanced thermal management system driven by phase change materials for power lithium-ion batteries: A review
Power lithium-ion batteries are widely utilized in electric vehicles (EVs) and hybrid electric vehicles (HEVs) for their high energy densities and long service-life. However, thermal safety problems mainly resulting from thermal runaway (TR) must be solved. In general, temperature directly influences the performance of lithium-ion batteries. Hence, an efficient thermal management system is very necessary for battery modules/packs. One particular approach, phase change material (PCM)-based cooling, has exhibited promising applicability due to prominent controlling-temperature and stretching-temperature capacities. However, poor thermal conductivity performance, as the main technical bottleneck, is limiting the practical application. Nevertheless, only promoting the thermal conductivity is far from enough considering the practical application in EVs/HEVs. To fix these flaws, firstly, the heat generation/transfer mechanisms of lithium-ion power batteries were macro- and microscopically reviewed. Following that, the thermal conductivity, structural stability, and flame retardancy of PCM are thoroughly discussed, to which solutions to the aforementioned performances are systematically reviewed. In addition, battery thermal management system (BTMS) employing PCM is illustrated and compared. Eventually, the existing challenges and future directions of PCM-based BTMS are discussed. In summary, this review presents effective approaches to upgrade the PCM performances for high-density lithium-ion BTMS. These strategies furtherly accelerate the commercialization process of PCM BTMS.
DOI: 10.1039/d0ta05247g
2020
Cited 105 times
Custom design of solid–solid phase change material with ultra-high thermal stability for battery thermal management
The custom-designed solid–solid phase change material possesses ultra-high thermal stability and exhibits outstanding battery thermal management performance.
DOI: 10.1038/s41467-021-21676-5
2021
Cited 91 times
Thermochromic aggregation-induced dual phosphorescence via temperature-dependent sp3-linked donor-acceptor electronic coupling
Abstract Aggregation-induced emission (AIE) has proven to be a viable strategy to achieve highly efficient room temperature phosphorescence (RTP) in bulk by restricting molecular motions. Here, we show that by utilizing triphenylamine (TPA) as an electronic donor that connects to an acceptor via an sp 3 linker, six TPA-based AIE-active RTP luminophores were obtained. Distinct dual phosphorescence bands emitting from largely localized donor and acceptor triplet emitting states could be recorded at lowered temperatures; at room temperature, only a merged RTP band is present. Theoretical investigations reveal that the two temperature-dependent phosphorescence bands both originate from local/global minima from the lowest triplet excited state (T 1 ). The reported molecular construct serves as an intermediary case between a fully conjugated donor-acceptor system and a donor/acceptor binary mix, which may provide important clues on the design and control of high-freedom molecular systems with complex excited-state dynamics.
DOI: 10.1016/j.cej.2021.133934
2022
Cited 83 times
Cross-linked cellulose/carboxylated polyimide nanofiber separator for lithium-ion battery application
Polyimide (PI) membranes with superior chemical resistance, insulation and self-extinguishing are attracting numerous attentions as the separators of lithium-ion batteries (LIBs), but significant challenges of low mechanical strength and poor electrolyte affinity still remain. Herein, a new kind of environmentally friendly hydrogen-bond (H-bond) cross-linked cellulose/carboxylated PI (Cellulose/PI-COOH) nanofiber composite separator is prepared via electrospinning followed by imidization and alkaline hydrolysis. Besides inheriting the high porosity of the pristine PI separator to absorb the electrolyte, the three-dimensional interconnected structure resulting from H-bond cross-linking is beneficial to improving the mechanical properties of the composite separator, and thereby delivers a tensile strength of 34.2 MPa, 5 times higher than that of the pristine PI separator (6.8 MPa). Meanwhile, the exposed hydroxyl groups on the cellulose, and carboxyl and imino groups on the carboxylated PI can also enhance the electrolyte affinity and wettability of the Cellulose/PI-COOH separator, which plays an important role in increasing the ionic conductivity (0.51 mS cm−1) and widening the electrochemical stability window (∼5.1 V). Consequently, compared with the polypropylene separator and PI separator, the H-bond cross-linked Cellulose/PI-COOH separators show better cycle performance and rate performance when adopted in lithium iron phosphate (LiFePO4) and lithium cobaltate (LiCoO2) half-cells. For example, the Cellulose/PI-COOH-based LiFePO4 half-cell demonstrates the highest initial discharge capacity of 166.2 mAh g−1 and capacity retention rate of 90%, much higher than the pristine PI-based LiFePO4 half-cell (114.6 mAh g−1, 86%). Furthermore, the much enhanced tensile strength, flexibility, thermal stability and flame-resistance of the Cellulose/PI-COOH separator are believed to greatly enhance the safety performance of the obtained LIBs.
DOI: 10.1016/j.ensm.2022.09.007
2022
Cited 83 times
Safety issue on PCM-based battery thermal management: Material thermal stability and system hazard mitigation
Although lithium-ion batteries are increasingly being used to achieve cleaner energy, their thermal safety is still a major concern, particularly in the fields of energy-storage power stations and electric vehicles with high energy-storage density. Therefore, the battery thermal management systems (BTMs) have been extensively applied, among which phase-change-material (PCM)-based BTMs are being developed at a high growth rate. As highlighted here, because of the risk of battery thermal hazards such as thermal runaway or battery fires, meeting the prerequisites of PCM-based BTMs is imperative not only for aiding in heat dissipation in regular operation conditions, but also for facilitating thermal hazard mitigation in the case of extreme accidents. The thermo-physical properties of modified PCMs are compared, highlighting their thermal stability and flame retardancy. Structure-enhanced PCM-based BTMs are compared in terms of their structural design for hazard mitigation. Finally, future research directions based on critical thinking are proposed for the use of PCM-based BTMs in system resilience. We anticipate that this review will provide new insights and draw more attention to the material/system reliability of self-safety PCM-based BTMs in future designs, especially in terms of thermal safety issues.
DOI: 10.1109/tcyb.2020.3005800
2021
Cited 75 times
Composite Neural Learning Fault-Tolerant Control for Underactuated Vehicles With Event-Triggered Input
This article presents a novel composite neural learning fault-tolerant algorithm to implement the path-following activity of underactuated vehicles with event-triggered input. With the input event-triggered mechanism, the dominant superiority is to reduce the communication burden in the channel from the controller to actuators. In the proposed scheme, the system uncertainties are dealt with in the fusion of the neural networks (NNs) and the dynamic surface control (DSC) method. The serial-parallel estimation model (SPEM) is constructed to estimate the error dynamics, where the derived prediction error could improve the compensation effect of the NNs. As for the gain uncertainties and the unknown actuator faults, four adaptive parameters are designed to stabilize the related perturbation and not be affected by the triggering instants. Based on the direct Lyapunov theorem, considerable efforts have been made to guarantee the semiglobal uniformly ultimately bounded (SGUUB) stability of the closed-loop system. Finally, comparison and practical experiments are illustrated to verify the superiority of the proposed algorithm.
DOI: 10.1016/j.scitotenv.2021.145463
2021
Cited 75 times
Comprehensive estimation of lake volume changes on the Tibetan Plateau during 1976–2019 and basin-wide glacier contribution
Volume changes and water balances of the lakes on the Tibetan Plateau (TP) are spatially heterogeneous and the lake-basin scale drivers remain unclear. In this study, we comprehensively estimated water volume changes for 1132 lakes larger than 1 km2 and determined the glacier contribution to lake volume change at basin-wide scale using satellite stereo and multispectral images. Overall, the water mass stored in the lakes increased by 169.7 ± 15.1 Gt (3.9 ± 0.4 Gt yr−1) between 1976 and 2019, mainly in the Inner-TP (157.6 ± 11.6 or 3.7 ± 0.3 Gt yr−1). A substantial increase in mass occurred between 1995 and 2019 (214.9 ± 12.7 Gt or 9.0 ± 0.5 Gt yr−1), following a period of decrease (−45.2 ± 8.2 Gt or −2.4 ± 0.4 Gt yr−1) prior to 1995. A slowdown in the rate of water mass increase occurred between 2010 and 2015 (23.1 ± 6.5 Gt or 4.6 ± 1.3 Gt yr−1), followed again by a high value between 2015 and 2019 (65.7 ± 6.7 Gt or 16.4 ± 1.7 Gt yr−1). The increased lake-water mass occurred predominately in glacier-fed lakes (127.1 ± 14.3 Gt) in contrast to non-glacier-fed lakes (42.6 ± 4.9 Gt), and in endorheic lakes (161.9 ± 14.0 Gt) against exorheic lakes (7.8 ± 5.8 Gt) over 1976–2019. Endorheic and glacier-fed lakes showed strongly contrasting patterns with a remarkable storage increase in the northern TP and slight decrease in the southern TP. The ratio of excess glacier meltwater runoff to lake volume increase between 2000 and ~2019 was less than 30% for the entire Inner-TP based on several independent data sets. Among individual lake-basins, 14 showed a glacier contribution to lake volume increase of 0.3% to 29.1%. The other eight basins exhibited a greater glacier contribution of 116% to 436%, which could be explained by decreased net precipitation. The lake volume change and basin scale glacier contribution reveal that the enhanced precipitation predominantly drives lake volume increase but it is spatially heterogeneous.
DOI: 10.1016/j.jjimei.2022.100058
2022
Cited 67 times
Time-series forecasting of seasonal items sales using machine learning – A comparative analysis
There has been a growing interest in the field of neural networks for prediction in recent years. In this research, a public dataset including the sales history of a retail store is investigated to forecast the sales of furniture. To this aim, several forecasting models are applied. First, some classical time-series forecasting techniques such as Seasonal Autoregressive Integrated Moving Average (SARIMA) and Triple Exponential Smoothing are utilized. Then, more advanced methods such as Prophet, Long Short-Term Memory (LSTM), and Convolutional Neural Network (CNN) are applied. The performances of the models are compared using different accuracy measurement methods (e.g., Root Mean Squared Error (RMSE) and Mean Absolute Percentage Error (MAPE)). The results show the superiority of the Stacked LSTM method over the other methods. In addition, the results indicate the good performances of the Prophet and CNN models.
DOI: 10.1016/j.matt.2022.07.010
2022
Cited 64 times
Highly efficient and persistent room temperature phosphorescence from cluster exciton enables ultrasensitive off-on VOC sensing
<h2>Summary</h2> Room temperature phosphorescence (RTP) materials have attracted wide attention due to their application potential in sensing, data-encryption, bioimaging, and optoelectronic devices. However, improving RTP efficiency and lifetime simultaneously in metal-free systems remains the biggest challenge for realizing their applications. Herein, by exploiting long-lifetime triplets of naphthalene (NL) and intersystem crossing (ISC)-promoting factors from 1,4-dichlorobenzene (DCB), we unveil a guest/host system (NL/DCB) with concurrently high RTP quantum yield of >20% and ultralong lifetime of >760 ms (duration ∼10 s) at ambient conditions. Based on systematic experimental and theoretical investigations, the underlying mechanism for efficient RTP of NL/DCB is mainly elucidated to be the formation of cluster excitons that boost ISC and triplet population of NL molecules. Meanwhile, we showcase the first example of fast and ultrasensitive detection of a common hazardous VOC via turning on its ultralong afterglow by using NL/DCB RTP, opening another avenue for practical applications of purely organic phosphorescence.
DOI: 10.1038/s41467-022-32903-y
2022
Cited 64 times
Polyvinyl chloride degradation by a bacterium isolated from the gut of insect larvae
Evidence for microbial degradation of polyvinyl chloride (PVC) has previously been reported, but little is known about the degrading strains and enzymes. Here, we isolate a PVC-degrading bacterium from the gut of insect larvae and shed light on the PVC degradation pathway using a multi-omic approach. We show that the larvae of an insect pest, Spodoptera frugiperda, can survive by feeding on PVC film, and this is associated with enrichment of Enterococcus, Klebsiella and other bacteria in the larva's gut microbiota. A bacterial strain isolated from the larval intestine (Klebsiella sp. EMBL-1) is able to depolymerize and utilize PVC as sole energy source. We use genomic, transcriptomic, proteomic, and metabolomic analyses to identify genes and proteins potentially involved in PVC degradation (e.g., catalase-peroxidase, dehalogenases, enolase, aldehyde dehydrogenase and oxygenase), and propose a PVC biodegradation pathway. Furthermore, enzymatic assays using the purified catalase-peroxidase support a role in PVC depolymerization.
DOI: 10.1016/j.energy.2021.122087
2022
Cited 55 times
Mitigation effects on thermal runaway propagation of structure-enhanced phase change material modules with flame retardant additives
Majority existing organic composite phase change materials (CPCMs) are flammable that result in thermal hazards such as fire and explosions in battery modules. Furthermore, the performance of PCM-based battery modules in extreme conditions like thermal runaway has not been studied adequately. In this study, a tubular CPCM-cell structure is designed using physically flame-retardant-modified CPCMs, and a series of experiments on the CPCMs with/without real cells is conducted with calorimeter tests and SEM analysis on morphology structure. First, the calorimeter tests and comparison on the heat release rate (HRR) are conducted on the CPCMs with and without flame retardant additives. Results show that the addition of Al(OH)3 reduced the HRR from 242.5 to 204.4 kW/m2 with 15 wt% additives. Besides, the analysis of the mitigating performances of structure-enhanced tubular module and traditional cuboid module with real batteries is conducted. A factor of safety (FOS) parameter is defined to evaluate the safety degree of thermal runaway domino with energy density. The FOS of blank, CPCM–0C, and CPCM–15C modules are 0, 3.59, and 16.67, respectively, while that of CPCM-15T reaches 21.01, indicating a significant improvement on mitigating effects by structure enhancement compared to adding flame retardant additives. This study brings novelty in the design of PCM-based battery modules, particularly from the thermal safety prospect.
DOI: 10.1016/j.cej.2022.137733
2022
Cited 54 times
Temperature control of battery modules through composite phase change materials with dual operating temperature regions
The phase change material (PCM)-based battery thermal management technology still remains a contradiction of guaranteeing a suitable operating temperature (20–40 ℃) of the batteries under regular working conditions, while avoiding the malfunction of the PCM under high ambient temperature (>40 ℃). Therefore, a novel composite PCM (CPCM) possessing dual phase change temperature regions (PCTRs) is designed herein by in-situ constructing a phase-changeable polymer (PCP) framework in the polyethylene glycol (PEG)/expanded graphite (EG) slurry. As prepared, the lower PCTR at 31.7–42.1 ℃ from the PCP framework provides a latent heat of 35.0 J g−1, while the higher PCTR at 42.1–51.2 ℃ from the PEG offers a latent heat of 68.3 J g−1. Additionally, the nanoscaled PCP framework strongly adsorbs the PEG, preventing the leakage phenomenon (mass loss < 1%), and the uniformly dispersed EG endows the CPCM with a high thermal conductivity of 1.98 W m−1 K−1. In consequence, under the normal ambient temperature of 25 ℃, the lower PCTR effectively keeps the battery module operating within the suitable temperature range of 25.9–34.9 ℃ and with a low temperature difference (ΔT) of 2.4 ℃ at the discharge rate of 1C. For comparison, the battery module adopting classical CPCM with a single PCTR at 40.9–55.1 ℃ demonstrates a much higher temperature range and maximum ΔT at 28.0–40.9 ℃ and 4.8 ℃, respectively. Under the high ambient temperature of 40 ℃, the higher PCTR starts to work like the single PCTR of traditional CPCMs, and controls the Tmax and ΔT of the module below 49.2 and 2.2 ℃ at the discharge rate of 1C, respectively, preventing thermal hazards.
DOI: 10.1016/j.neucom.2022.04.081
2022
Cited 46 times
TIPCB: A simple but effective part-based convolutional baseline for text-based person search
Text-based person search is a sub-task in the field of image retrieval, which aims to retrieve target person images according to a given textual description. The significant feature gap between two modalities makes this task very challenging. Many existing methods attempt to utilize local alignment to address this problem in the fine-grained level. However, most relevant methods introduce additional models or complicated training and evaluation strategies, which are hard to use in realistic scenarios. In order to facilitate the practical application, we propose a simple but effective baseline for text-based person search named TIPCB (i.e., Text-Image Part-based Convolutional Baseline). Firstly, a novel dual-path local alignment network structure is proposed to extract visual and textual local representations, in which images are segmented horizontally and texts are aligned adaptively. Then, we propose a multi-stage cross-modal matching strategy, which eliminates the modality gap from three feature levels, including low level, local level and global level. Extensive experiments are conducted on the widely-used benchmark datasets (CUHK-PEDES and ICFG-PEDES) and verify that our method outperforms all the existing methods. Our code has been released in https://github.com/OrangeYHChen/TIPCB.
DOI: 10.1007/s11426-022-1299-5
2022
Cited 45 times
Heterostructured NiS2@SnS2 hollow spheres as superior high-rate and durable anodes for sodium-ion batteries
DOI: 10.1016/j.jclepro.2021.129718
2022
Cited 44 times
Innovative thermal management and thermal runaway suppression for battery module with flame retardant flexible composite phase change material
Thermal runaway severely affects the lithium batteries under conditions of non-normal forces or thermal abuse. In this study, a novel flame retardant flexible composite phase change material is successfully prepared, and a battery module based on it is designed and experimentally investigated. Herein, paraffin with high latent heat is performed as phase change material, Styrene-butadiene-styrene is employed as the supporting material, expanded graphite is used as the additive for thermal conductivity enhancement, and a flame retardant is utilized to suppress the heat diffusion and resistant flame. Experimental results reveal that a flame retardant flexible composite phase change material with 15 wt% flame retardant can achieve the optimum flame retardant effect, and its limiting oxygen index value can reach 35.9%. The battery thermal management with 15 wt% flame retardant composite phase change material can effectively avoid the heat accumulation of the battery module in the long cycle. In addition, thermal runaway trigger is simulated by heating rod at 200 °C, and the effect of the different composite phase change material modules on thermal runaway spread are compared. The result reveals that the flame retardant flexible composite phase change material could absorb and transfer the heat of the triggered battery timely and promptly, exhibiting a flame retardant effect necessary to avoid thermal runaway of the battery.
DOI: 10.1016/j.watres.2022.118636
2022
Cited 43 times
Micro(nano)plastic size and concentration co-differentiate nitrogen transformation, microbiota dynamics, and assembly patterns in constructed wetlands
Micro/nano-sized plastics (MPs/NPs) existing in wastewater system are the potential threats to nitrogen (N) biotransformation. Constructed wetlands (CWs) as wastewater treatment systems are considered the important barriers preventing MPs/NPs from entering the open water. However, little is known about how the accumulation of MPs/NPs affects microbial N transformation, dynamics, assembly, and metabolism of wetland microbiota. Herein, we constructed 12 wetland systems to address the above knowledge gaps over 300-day exposure to different sizes (3 mm - 60 nm) and concentrations (10 - 1000 μg/L) of MPs/NPs. The results showed that MPs/NPs accumulation caused decrease in NH4+-N removal (by 7.6% - 71.2%) and microbial diversity and intriguingly altered microbiota composition (especially in the high-concentration groups) without damage on the high removal efficiency of NO3--N and NO2--N (66.2% - 99.8%) in all except for the nano-sized plastic-exposed wetlands. Moreover, MPs/NPs exposure induced shift in the strengths of non-random species aggregation and segregation patterns co-differentiated by the size and concentration of MPs/NPs, and MPs/NPs accumulation created size-differentiated alternative niches for nitrogen-transforming bacteria, e.g., canonical nitrifiers (Nitrospira and Nitrosomonas) and denitrifiers (Thauera, Comamonas, and Aquabacterium), which were enriched in MPs groups where denitrifying enzyme-coding genes were also enriched, suggesting potential positive impact of larger plastics on denitrification. Our study highlights MPs/NPs-induced divergence in microbiota dynamics and nitrogen transformation in CWs, and provides important insights into how microbiota structurally and functionally respond to long-term MPs/NPs disturbance.
DOI: 10.1109/tcns.2022.3220705
2023
Cited 42 times
A Novel Cooperative Design for USV–UAV Systems: 3-D Mapping Guidance and Adaptive Fuzzy Control
This work investigates a novel cooperative design for path following of the mixed-order underactuated surface vehicle (USV) and unmanned aerial vehicle (UAV) in the presence of the structure uncertainties and external disturbances. The designed cooperative scheme is comprised of the 3-D mapping guidance and adaptive fuzzy control algorithm. The 3-D mapping guidance is developed to provide the reference signals of the yaw degree of freedom for the USV and UAV by utilizing the equivalent mapping technique. To control the USV–UAV converge to the desired path, the adaptive fuzzy control algorithm is designed for the position and attitude loops by fusing the dynamic surface control (DSC) and the backstepping techniques. The position loop can generate the thrust inputs for the USV–UAV and provide the desired rolling and pitching angles for the UAV by using the nonlinear decoupling method. In the proposed algorithm, the model uncertainties are approximated by the fuzzy logic system and only eight norm-based adaptive parameters are required to be updated online. Based on the Lyapunov theorem, the stability of the position loop and the attitude loop for the USV–UAV systems is achieved and all signals in the cooperative systems are the semiglobal uniform ultimate bounded (SGUUB). The superiorities and the effectiveness of the proposed strategy are verified through the numerical experiment on the MATLAB platform under the external disturbances.
DOI: 10.1002/anie.202218712
2023
Cited 30 times
Functional Roles of Polymers in Room‐Temperature Phosphorescent Materials: Modulation of Intersystem Crossing, Air Sensitivity and Biological Activity
Organic room-temperature phosphorescent (RTP) materials routinely incorporate polymeric components, which usually act as non-functional or "inert" media to protect excited-state phosphors from thermal and collisional quenching, but are lesser explored for other influences. Here, we report some exemplary "active roles" of polymer matrices played in organic RTP materials, including: 1) color modulation of total delayed emissions via balancing the population ratio between thermally-activated delayed fluorescence (TADF) and RTP due to dielectric-dependent intersystem crossing; 2) altered air sensitivity of RTP materials by generating various surface morphologies such as nano-sized granules; 3) enhanced bacterial elimination for enhanced electrostatic interactions with negatively charged bio-membranes. These active roles demonstrated that the vast library of polymeric structures and functionalities can be married to organic phosphors to broaden new application horizons for RTP materials.
DOI: 10.1016/j.ijthermalsci.2022.107877
2023
Cited 29 times
A novel strategy to optimize the liquid cooling plates for battery thermal management by precisely tailoring the internal structure of the flow channels
Liquid cooling plate (LCP) is widely used in liquid cooling technology for battery thermal management (BTM), and numerous investigations have been devoted to the design of the LCP shape and the macroscopic cooling structures. Here, we focus on an effective but neglected strategy of optimizing the internal structure of the LCPs to enhance the cooling performance. As inspired by the baffle plates commonly adopted in heat exchangers, splitters with various numbers and patterns are introduced into the flow channels of the LCPs, and the relationship between the internal structure and the temperature-control performance of the LCPs are thus investigated. The results show that the increase of the splitter numbers within a certain range effectively reduces the temperature and temperature difference. Furthermore, in spite of the relatively high energy consumption, the double-side pattern with a splitter number of 20–30 demonstrates the optimal cooling effect for the battery modules. These encouraging results may raise concerns about constructing a suitable internal structure of the LCPs more precisely to realize a target-oriented application, particularly those targeting higher cost-efficiency.
DOI: 10.1016/j.seppur.2022.122921
2023
Cited 19 times
Preparation of Nylon-6 micro-nanofiber composite membranes with 3D uniform gradient structure for high-efficiency air filtration of ultrafine particles
Compared of traditional melt-blown nonwoven materials, micro-nanofiber composite membranes with uniform spatial gradient structure will be the development trend of high efficiency and low resistance filtration materials, especially against ultrafine particles with kinetic diameter less than 0.25 (PM0.25). Herein, Nylon-6 micro-nanofiber composite membranes (Nylon-6 FCMs) with three-dimensional (3D) uniform gradient structure were prepared by air jet spinning under the help of PEO. The fluffy 3D gradient structure possessed a uniform gradual pore gradient from large to small, ensuring the PM0.25 were captured by exact grading under high gas flow due to the form of special "trumpet-like" gas passage inside the membranes. The structure of Nylon-6 FCMs could be controlled and exhibited high tensile strength, good moisture permeability, excellent filtration performance. Among them, the FCM-1 with a uniform gradual pore gradient could achieve the optimal filtering performance with filtration efficiency (99.99 %) and pressure drop (144 Pa). The mask prepared using this Nylon-6 FCMs also displayed good protective effect with comparable air permeability (221.84 mm·s−1) and moisture permeability (181.84 g·m−2·h−1) compared of commercial melt-blown masks. Most importantly, this mask prepared still could maintain good filtration performance even in high temperature and high humidity environment, providing users more comfortable wearing experience and stable protection performance, especially under the current COVID-19 outbreak.
DOI: 10.1016/j.cej.2023.141833
2023
Cited 18 times
Visible-light-driven photodegradation of xanthate in a continuous fixed-bed photoreactor: Experimental study and modeling
Photocatalysis has been widely employed as a promising method for wastewater treatment. However, existing studies are primarily conducted in batch reactors. To the best of our knowledge, a continuous reactor has not been used to degrade xanthate residual in mineral beneficiation wastewater. In this work, a continuous fixed-bed photoreactor (CFPR) was first designed, and Bi2WO6 photocatalysts coated on silica sands were used to degrade sodium isobutyl xanthate (SIBX) under visible light irradiation. The effects of various parameters, including catalyst loading, pH level, initial SIBX concentration, wastewater flow rate, calcium ion (Ca2+) concentration, magnesium ion (Mg2+) concentration, and zinc ions (Zn2+), on the degradation efficiency, were systematically investigated. The results show that the photodegradation percentage of SIBX increases with increasing catalyst loading, decreasing initial concentration, and decreasing flow rate within the scope under investigation. Additionally, low concentrations (30 mg·L−1) of Ca2+ and Mg2+ ions favor the photodegradation of SIBX, whereas excessive Ca2+ and Mg2+ ions (240 mg·L−1) inhibit photocatalytic activity. The presence of Zn2+ ions inhibits photodegradation percentage. Furthermore, the photodegradation percentage is slightly higher at alkaline than at acidic pH. The maximum degradation percentage reached 95.40 % after 70 min of visible light irradiation under optimal conditions. In addition, a fixed bed reactor model considering surface reaction kinetics and mass transfer constraints was established by combining the Langmuir-Hinshelwood (L-H) kinetic equations and the series resistance theory. This model can accurately estimate the intrinsic kinetic parameters and can well predict degradation efficiency with a root-mean-square-error (RMSE) of 4.24 %. Finally, the bottleneck for improving the performance of the reactor can be identified under different conditions.
DOI: 10.1109/tiv.2023.3317336
2024
Cited 6 times
Cooperative Path Following Control of USV-UAVs Considering Low Design Complexity and Command Transmission Requirements
This paper investigates a robust cooperative path following control algorithm for an unmanned surface vessel and unmanned aerial vehicles (USV-UAVs) that releases the design complexity and command transmission requirements for the potential significance to implement a maritime square search mission. The latter is a classical search pattern suggested by the international aeronautical and maritime search and rescue (IAMSAR) manual. To program the reference signals for the USV-UAVs simultaneously, the reference routes are programmed that uses a virtual ship and a virtual aerial. Therein, the information of the virtual aerials can be mapped from a virtual ship. Further, the desired attitude angles are derived under the cooperative virtual guidance framework. For a control part, a novel threshold rule of the dynamic event-triggered mechanism is reconstructed according to output errors to avoid the artificial parameter tuning and reduce the data transmission load from the controllers to the actuators. Besides, a L-function is designed to eliminate an effect caused by the model nonlinearities and disturbances. This ensures a lower design complexity of the control system. The stability of the proposed control algorithm is proved via the Lyapunov theorem. Finally, the effectiveness and the reasonable are evaluated on the simulation platform.
DOI: 10.1016/j.neulet.2004.03.036
2004
Cited 186 times
Astragaloside IV protects against ischemic brain injury in a murine model of transient focal ischemia
Astragalus membranaceus is a herbal medicine that has been used clinically in stroke patients in China for decades, but its potential neuroprotective effect against ischemic brain injury has not been experimentally tested. In this study, we investigated the effect of Astragaloside IV, a purified extract from Astragalus membranaceus, in a murine model of focal cerebral ischemia/reperfusion produced by transient (1.5 h) middle cerebral artery occlusion. As determined at 72 h after ischemia, post-ischemic treatment of Astragaloside IV (20 or 40 mg/kg) markedly and significantly (P < 0.03 vs. vehicle-treated animals) reduced infarct volume. Astragaloside IV treatment also decreased the levels of malondialdehyde, an indicator of lipid peroxidation, and increased the levels of the antioxidant enzymes glutathione peroxidase and superoxide dismutase in ischemic tissues. The results presented here provide the first evidence of a neuroprotective effect of Astragaloside IV in the model of ischemic brain injury. We suggest that the anti-infarction effect by Astragaloside IV may be derived at least in part from its antioxidant properties.
DOI: 10.1021/ic300077g
2013
Cited 164 times
Aromatic Difluoroboron β-Diketonate Complexes: Effects of π-Conjugation and Media on Optical Properties
Aromatic difluoroboron β-diketonate complexes (BF2bdks) are classic fluorescent molecules that have been explored as photochemical reagents, two-photon dyes, and oxygen sensors. To gain a better understanding of their emissive properties in both solution and polymer matrices, BF2bdks with varying aromatic groups were synthesized and their photophysical properties were investigated in both methylene chloride and poly(lactic acid) (PLA). Absorption spectra showed systematic variations that are well correlated with structural features, including the size of the aryl substituent and the presence of a para electron-donating methoxy substituent. Computational modeling of the absorption spectra with the TD-B3LYP/6-311+G(d)//B3LYP/6-31G(d) formulation of density functional theory and a polarizable continuum model of dichloromethane solvent shows that all systems show intense π-π* one-electron excitations, usually from one of the highest occupied molecular orbitals (HOMO - k, k = 0, 1, 2) to the lowest unoccupied molecular orbital (LUMO). Emission properties are sensitive to the dye structure and medium. Based on spectroscopic and lifetime studies, BF2bdks exhibit comparable fluorescence properties in both solutions and polymers when the diketonate group is functionalized with smaller aromatic ring systems such as benzene. For BF2bdks with larger arene ring systems, such as anthracene, emission from a strong intramolecular charge-transfer (ICT) state was also noted in both solution and in PLA. There are differences in relative intensities of peaks arising from π-π* and ICT excitations depending upon dye loading in PLA. Substituent effects were also observed. Electron-donating methoxyl groups on the aromatic rings lead to enhanced fluorescence quantum yields. For certain dyes, phosphorescence is detected at low temperature or under a nitrogen atmosphere in PLA matrices.
DOI: 10.1039/c1jm00067e
2011
Cited 159 times
Alkyl chain length effects on solid-state difluoroboron β-diketonate mechanochromic luminescence
Solid-state difluoroboron β-diketonate dyes display reversible mechanochromic luminescence (ML). To test the effects of alkyl chain length on solid state photoluminescence and ML, a series of dyes, BF2dbmOR, with dibenzoylmethane (dbm) ligands and alkoxyl substituents (–OR) were prepared, where R = CnH2n+1 and n = 1, 2, 3, 5, 6, 12, 14, 16, 18. Emission properties were investigated in solution and in the solid state. Fluorescence spectra and lifetimes were nearly identical for dyes in CH2Cl2 solution; whereas, in the solid state, as powders, thin films or spin cast films, emission maxima, and lifetimes were different among the samples. Solid-state ML emission spectra were monitored at room temperature as a function of time for smeared powders on quartz surfaces. The recovery time generally increased with alkyl chain length, ranging from minutes (n = 3) to days (n = 18). Longer chain analogues (n = 6, 12, 14, 16, 18) did not fully return to the original annealed emissive state even after months on quartz, though the dynamics are substrate dependent. Solid-state dyes were also investigated by XRD and DSC (powders), and by AFM (spin cast films).
DOI: 10.1038/nprot.2011.349
2011
Cited 158 times
In vivo optical molecular imaging and analysis in mice using dorsal window chamber models applied to hypoxia, vasculature and fluorescent reporters
Optical techniques for functional imaging in mice have a number of key advantages over other common imaging modalities such as magnetic resonance imaging, positron emission tomography or computed tomography, including high resolution, low cost and an extensive library of available contrast agents and reporter genes. A major challenge to such work is the limited penetration depth imposed by tissue turbidity. We describe a window chamber technique by which these limitations can be avoided. This facilitates the study of a wide range of processes, with potential endpoints including longitudinal gene expression, vascular remodeling and angiogenesis, and tumor growth and invasion. We further describe several quantitative imaging and analysis techniques for characterizing in vivo fluorescence properties and functional endpoints, including vascular morphology and oxygenation. The procedure takes ∼2 h to complete, plus up to several weeks for tumor growth and treatment procedures.
DOI: 10.1002/ange.201105735
2011
Cited 158 times
A General Strategy To Construct Fluorogenic Probes from Charge‐Generation Polymers (CGPs) and AIE‐Active Fluorogens through Triggered Complexation
Aktiver Analyt: Ein wässriges fluorogenes Sensorsystem bestehend aus selektiven und spezifischen analytresponsiven ladungserzeugenden Polymeren (CGPs) und einem negativ geladenen Fluorogen mit aggregationsinduzierter Emission (TPE-COOH4) wird beschrieben. In Gegenwart des Analyten bilden die CGPs einen elektrostatischen Komplex mit TPE-COOH4, und es kommt zu einer intensiven Fluoreszenzemission durch die Aggregation von TPE-COOH4. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
DOI: 10.1002/anie.201105735
2011
Cited 151 times
A General Strategy To Construct Fluorogenic Probes from Charge‐Generation Polymers (CGPs) and AIE‐Active Fluorogens through Triggered Complexation
Trip the light of plastic: An aqueous fluorogenic sensing system consisting of selective and specific analyte-triggerable charge-generation polymers (CGPs) and a negatively charged aggregation-induced emission active fluorogen (TPE-COOH4) is presented. In the presence of a triggering analyte of interest, the CGPs undergo electrostatic complexation with TPE-COOH4 leading to intense fluorescence emission due to the aggregation of TPE-COOH4. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
DOI: 10.1371/journal.pntd.0002831
2014
Cited 138 times
Distribution and Clinical Manifestations of Cryptosporidium Species and Subtypes in HIV/AIDS Patients in Ethiopia
Background Cryptosporidiosis is an important cause for chronic diarrhea and death in HIV/AIDS patients. Among common Cryptosporidium species in humans, C. parvum is responsible for most zoonotic infections in industrialized nations. Nevertheless, the clinical significance of C. parvum and role of zoonotic transmission in cryptosporidiosis epidemiology in developing countries remain unclear. Methodology/Principal Findings In this cross-sectional study, 520 HIV/AIDS patients were examined for Cryptosporidium presence in stool samples using genotyping and subtyping techniques. Altogether, 140 (26.9%) patients were positive for Cryptosporidium spp. by PCR-RFLP analysis of the small subunit rRNA gene, belonging to C. parvum (92 patients), C. hominis (25 patients), C. viatorum (10 patients), C. felis (5 patients), C. meleagridis (3 patients), C. canis (2 patients), C. xiaoi (2 patients), and mixture of C. parvum and C. hominis (1 patient). Sequence analyses of the 60 kDa glycoprotein gene revealed a high genetic diversity within the 82 C. parvum and 19 C. hominis specimens subtyped, including C. parvum zoonotic subtype families IIa (71) and IId (5) and anthroponotic subtype families IIc (2), IIb (1), IIe (1) and If-like (2), and C. hominis subtype families Id (13), Ie (5), and Ib (1). Overall, Cryptosporidium infection was associated with the occurrence of diarrhea and vomiting. Diarrhea was attributable mostly to C. parvum subtype family IIa and C. hominis, whereas vomiting was largely attributable to C. hominis and rare Cryptosporidium species. Calf contact was identified as a significant risk factor for infection with Cryptosporidium spp., especially C. parvum subtype family IIa. Conclusions/Significance Results of the study indicate that C. parvum is a major cause of cryptosporidiosis in HIV-positive patients and zoonotic transmission is important in cryptosporidiosis epidemiology in Ethiopia. In addition, they confirm that different Cryptosporidium species and subtypes are linked to different clinical manifestations.
DOI: 10.1016/j.isatra.2017.11.008
2018
Cited 130 times
Leader-follower formation control of underactuated surface vehicles based on sliding mode control and parameter estimation
This paper studies the leader-follower formation control of underactuated surface vehicles with model uncertainties and environmental disturbances. A parameter estimation and upper bound estimation based sliding mode control scheme is proposed to solve the problem of the unknown plant parameters and environmental disturbances. For each of these leader-follower formation systems, the dynamic equations of position and attitude are analyzed using coordinate transformation with the aid of the backstepping technique. All the variables are guaranteed to be uniformly ultimately bounded stable in the closed-loop system, which is proven by the distribution design Lyapunov function synthesis. The main advantages of this approach are that: first, parameter estimation based sliding mode control can enhance the robustness of the closed-loop system in presence of model uncertainties and environmental disturbances; second, a continuous function is developed to replace the signum function in the design of sliding mode scheme, which devotes to reduce the chattering of the control system. Finally, numerical simulations are given to demonstrate the effectiveness of the proposed method.
DOI: 10.1002/anie.201808861
2018
Cited 130 times
Proton‐Activated “Off–On” Room‐Temperature Phosphorescence from Purely Organic Thioethers
Abstract Room‐temperature phosphorescence (RTP)‐based sensors have distinctive advantages over the fluorescence counterparts, such as larger Stokes shifts and longer lifetimes. Unfortunately, almost all RTP sensors are operated on quenching‐based mechanisms given the sensitive nature of the emissive triplet state. Here we report a type of thioether RTP molecules that shows RTP “turn‐on” when volatile acid vapors such as HCl are in contact. To elucidate the underlying mechanism, model thioethers containing different donor/acceptor combinations are investigated via fluorescence spectroscopy and theoretical calculations aided by molecular coordinates obtained from single‐crystal X‐ray diffraction. It is revealed that a charge‐transfer character in the phosphorescence state is crucial. The “turn‐on” design concept may significantly broaden the sensing application scope for organic RTP molecules.
DOI: 10.1021/nn7003525
2008
Cited 127 times
Boron Polylactide Nanoparticles Exhibiting Fluorescence and Phosphorescence in Aqueous Medium
Difluoroboron dibenzoylmethane-polylactide, BF(2)dbmPLA, a biocompatible polymer-luminophore conjugate was fabricated as nanoparticles. Spherical particles <100 nm in size were generated via nanoprecipitation. Intense blue fluorescence, two-photon absorption, and long-lived room temperature phosphorescence (RTP) are retained in aqueous suspension. The nanoparticles were internalized by cells and visualized by fluorescence microscopy. Luminescent boron biomaterials show potential for imaging and sensing.
DOI: 10.1021/ic100822s
2010
Cited 122 times
Control over Interpenetration in Lanthanide−Organic Frameworks: Synthetic Strategy and Gas-Adsorption Properties
Two isostructural lanthanide-organic frameworks (1 and 2) with 2-fold interpenetrating nets have been synthesized based on 1,4-benzenedicarboxylic acid (H(2)BDC). By application of an organic ligand with hindrance groups and a terminal chelating ligand to replace BDC and coordinated solvates, interpenetration has been effectively controlled. The gas-sorption properties of the noninterpenetrating net have been studied.
DOI: 10.1016/j.scib.2019.03.011
2019
Cited 113 times
Potentially dangerous glacial lakes across the Tibetan Plateau revealed using a large-scale automated assessment approach
Glacial lake outburst floods (GLOFs) are a major concern in the Himalaya and on the Tibetan Plateau (TP), where several disasters occurring over the past century have caused significant loss of life and damage to infrastructure. This study responds directly to the needs of local authorities to provide guidance on the most dangerous glacial lakes across TP where local monitoring and other risk reduction strategies can subsequently be targeted. Specifically, the study aims to establish a first comprehensive prioritisation ranking of lake danger for TP, considering both the likelihood and possible magnitude of any outburst event (hazard), and the exposure of downstream communities. A composite inventory of 1,291 glacial lakes (>0.1 km2) was derived from recent remote sensing studies, and a fully automated and object assessment scheme was implemented using customised GIS tools. Based on four core determinates of GLOF hazard (lake size, watershed area, topographic potential for ice/rock avalanching, and dam steepness), the scheme accurately distinguishes the high to very high hazard level of 19 out of 20 lakes that have previously generated GLOFs. Notably, 16% of all glacial lakes threaten human settlements, with a hotspot of GLOF danger identified in the central Himalayan counties of Jilong, Nyalam, and Dingri, where the potential trans-boundary threat to communities located downstream in Nepal is also recognised. The results provide an important and object scientific basis for decision-making, and the methodological approach is ideally suited for replication across other mountainous regions where such first-order studies are lacking.
DOI: 10.1145/2505515.2505541
2013
Cited 112 times
StaticGreedy
Influence maximization, defined as a problem of finding a set of seed nodes to trigger a maximized spread of influence, is crucial to viral marketing on social networks. For practical viral marketing on large scale social networks, it is required that influence maximization algorithms should have both guaranteed accuracy and high scalability. However, existing algorithms suffer a scalability-accuracy dilemma: conventional greedy algorithms guarantee the accuracy with expensive computation, while the scalable heuristic algorithms suffer from unstable accuracy
DOI: 10.1021/acsnano.9b02466
2019
Cited 111 times
Nanoclustered Cascaded Enzymes for Targeted Tumor Starvation and Deoxygenation-Activated Chemotherapy without Systemic Toxicity
Intratumoral glucose depletion-induced cancer starvation represents an important strategy for anticancer therapy, but it is often limited by systemic toxicity, nonspecificity, and adaptive development of parallel energy supplies. Herein, we introduce a concept of cascaded catalytic nanomedicine by combining targeted tumor starvation and deoxygenation-activated chemotherapy for an efficient cancer treatment with reduced systemic toxicity. Briefly, nanoclustered cascaded enzymes were synthesized by covalently cross-linking glucose oxidase (GOx) and catalase (CAT) via a pH-responsive polymer. The release of the enzymes can be first triggered by the mildly acidic tumor microenvironment and then be self-accelerated by the subsequent generation of gluconic acid. Once released, GOx can rapidly deplete glucose and molecular oxygen in tumor cells while the toxic side product, i.e., H2O2, can be readily decomposed by CAT for site-specific and low-toxicity tumor starvation. Furthermore, the enzymatic cascades also created a local hypoxia with the oxygen consumption and reductase-activated prodrugs for an additional chemotherapy. The current report represents a promising combinatorial approach using cascaded catalytic nanomedicine to reach concurrent selectivity and efficiency of cancer therapeutics.
DOI: 10.1016/j.tibs.2018.06.003
2018
Cited 109 times
Is β-Catenin a Druggable Target for Cancer Therapy?
As an oncogenic transcription factor, β-catenin was conventionally considered as an undruggable target. However, recent discoveries of small molecules that directly bind to β-catenin suggest that β-catenin is a potentially druggable target that is yet to be drugged. Purified recombinant protein is usually required for measuring binding to a ligand, while the conformation could be different from the native protein because it may lack post-translational modifications or endogenous interacting partners. The newly developed microscale thermophoresis technology allows determination of the physical binding between a small molecule and a cellular protein in cell lysate. For small molecules that directly bind proteins without inhibitory effects, it is useful to utilize an emerging protein depletion strategy that links the protein of interest to the endogenous protein degradation machinery. Mutations of canonical Wnt signaling pathway genes frequently occur in cancer and lead to abnormal accumulation of the key effector β-catenin. Over the past decades, a number of Wnt inhibitors have been identified through high-throughput screenings, however, very few of them target β-catenin directly, raising questions regarding its druggability. Here, we review Wnt inhibitors with a focus on small molecules that directly bind β-catenin, discuss the druggability of β-catenin, and why it has rarely been targeted, especially in the cellular context. We also propose strategies to develop small molecule binding and depleting cellular β-catenin, which are generally applicable to other difficult-to-drug or yet-to-be-drugged targets. Mutations of canonical Wnt signaling pathway genes frequently occur in cancer and lead to abnormal accumulation of the key effector β-catenin. Over the past decades, a number of Wnt inhibitors have been identified through high-throughput screenings, however, very few of them target β-catenin directly, raising questions regarding its druggability. Here, we review Wnt inhibitors with a focus on small molecules that directly bind β-catenin, discuss the druggability of β-catenin, and why it has rarely been targeted, especially in the cellular context. We also propose strategies to develop small molecule binding and depleting cellular β-catenin, which are generally applicable to other difficult-to-drug or yet-to-be-drugged targets.
DOI: 10.1039/c0jm04326e
2011
Cited 108 times
Arene effects on difluoroboron β-diketonate mechanochromic luminescence
Difluoroboron β-diketonate (BF2bdk) dyes display reversible mechanochromic luminescence (ML) in the solid state. A series of BF2bdk dyes with methyl, phenyl, naphthyl and anthracyl groups (i.e. arene substituents and bdk ligands: Me–Ph = mbm, Ph–Ph = dbm, Np–Ph = nbm, An–Ph = abm) were prepared to test the effects of π conjugation length and arene size on ML properties. Solid-state emission spectra were recorded for powders, spin-cast films, and dye coated weighing paper. The materials emit at various wavelengths from blue to red, depending on the conjugation length. Additionally, emission spectra were recorded for smeared solids and their recovery was tracked at room temperature over time. All dyes except for BF2mbm show emission changes upon mechanical perturbation, with increasing π conjugation correlating with more dramatic, redshifted fluorescence, however, their recovery is significantly affected by the aromatic substituents. The thermal and structural properties of the dyes in the solid state were also investigated by differential scanning calorimetry (DSC) and atomic force microscopy (AFM).
DOI: 10.1016/j.enconman.2019.112106
2019
Cited 108 times
Thermal performance of PCM and branch-structured fins for cylindrical power battery in a high-temperature environment
Battery modules with phase change material (PCM) cooling inevitably suffer from heat-storage saturation and poor secondary-heat dissipation, especially in high-temperature environments or hot regions. To optimize thermal management, this study firstly explores the thermal behaviors of PCMs with different phase change temperatures (PCTs) in a high-temperature environment. The experimental results show that a PCM with a PCT of 46 °C offers the best cooling effect at a high ambient temperature of 40 °C in this study. For example, the maximum temperature of a cell without PCM reaches 53.3 °C, whereas that of the cell with PCMs having PCTs 40, 46, and 55 °C, are 59.2, 51.6, and 57.5 °C, respectively, during the dynamic cycling process. Nevertheless, the application of above PCM is still unsatisfying because the maximum temperature of the battery in the PCM module exhibits obvious increasing trend with cycles in 40 °C environment. On this basis, several novel fins with multiple heat-flow channels (of V, Y and X shapes) are designed and introduced into the PCM module to enhance the secondary heat dissipation capability. These fins with innovative branch structures deliver excellent performance in alleviating the battery temperature than the traditional rectangular fins, which can be attributed to the ability of the branch structures to increase the heat transfer area by adding heat transfer channels. The results of this work show that the X-shape delivers the best performance in a high-temperature environment of 40 °C by maintaining the maximum temperature of the cell below 47 °C.
DOI: 10.1002/ijc.28706
2014
Cited 107 times
NMR and LC/MS-based global metabolomics to identify serum biomarkers differentiating hepatocellular carcinoma from liver cirrhosis
Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in the world. However, current biomarkers that discriminate HCC from liver cirrhosis (LC) are important but are limited. More reliable biomarkers for HCC diagnosis are therefore needed. Serum from HCC patients, LC patients and healthy volunteers were analyzed using NMR and LC/MS-based approach in conjunction with random forest (RF) analysis to discriminate their serum metabolic profiles. Thirty-two potential biomarkers have been identified, and the feasibility of using these biomarkers for the diagnosis of HCC was evaluated, where 100% sensitivity was achieved in detecting HCC patients even with AFP values lower than 20 ng/mL. The metabolic alterations induced by HCC showed perturbations in synthesis of ketone bodies, citrate cycle, phospholipid metabolism, sphingolipid metabolism, fatty acid oxidation, amino acid catabolism and bile acid metabolism in HCC patients. Our results suggested that these potential biomarkers identified appeared to have diagnostic and/or prognostic values for HCC, which deserve to be further investigated. In addition, it also suggested that RF is a classification algorithm well suited for selection of biologically relevant features in metabolomics.
DOI: 10.1002/er.4081
2018
Cited 105 times
Experimental investigation of thermal management system for lithium ion batteries module with coupling effect by heat sheets and phase change materials
Some potential safety risks for lithium ion battery such as overheating, combustion, and explosion occurred in practical application may cause accidents of electric vehicles. Phase change material (PCM)-based thermal management system was demonstrated as a feasible approach. However, the batteries have to endure various environment and climate, which would not work normally under cold area. Especially when the surrounding temperature falls to below 10°C, which can bring about the energy and power of Li-ion batteries rapidly reducing. In this study, a coupling heating strategy of the PCM-based batteries module with 2 heat sheets at low temperature was proposed for batteries module and cannot only balance the temperature among different batteries in the module but also ensure to pre-heat the batteries module at low temperature. The experiment displayed that 7% of EG in paraffin-based composite PCMs was the best proportion for batteries module, considering both fluidity and thermal conductivity factors. In addition, the temperature difference of PCM-based batteries module was 2.82°C, while that of the air-based one was 14.49°C, which was 5 times more than former, exhibiting an excellent performance in balancing temperature uniformly, and was beneficial for prolonging the lifespan of batteries. The coupling heating strategy-based PCM with heat sheets provided as an extremely promising technology for lithium batteries module at low temperature.
DOI: 10.1016/bs.pmbts.2018.12.011
2019
Cited 105 times
Serum CEA levels in 49 different types of cancer and noncancer diseases
Carcinoembryonic antigen (CEA) was first identified as colon cancer antigen in 1965. The higher serum CEA level than that of healthy individuals led to its clinical application as a diagnostic biomarker for colorectal cancer. Subsequent molecular biology studies revealed that CEA are glycoproteins from a family of 32 genes and are normally expressed in various tissues. Indeed, serum CEA levels are not only increased in colorectal cancer but also increased in other types of cancers and noncancer diseases. However, a systematic comparison of the serum CEA levels in different diseases has not been reported. In current study, serum CEA levels from 70,993 patients with 49 clinically defined diseases were retrieved in the clinical laboratory of Affiliated Hospital of Qingdao University over the past 5 years. In addition, serum CEA levels from 39,650 individuals who attended their annual physical examination were used as healthy controls. Based on the mean, median, and –Log10 p values, we found that patients suffering from 42 diseases had significantly increased serum CEA levels than that of healthy controls. Moreover, patients with lung fibrosis, pancreatic cancer, uremia, chronic obstructive pulmonary disease, colon cancer, Alzheimer's disease, rectum cancer, and lung cancer had highest media levels of serum CEA in a descending order. Furthermore, healthy individuals older than 65 years old ranked 24th out of 49 in the media levels of serum CEA. In summary, the increased serum CEA levels are associated with aging, cancers, and noncancer diseases and the molecular mechanisms behind the increased serum CEA levels in the 42 unrelated diseases need to be investigated.
DOI: 10.1039/c2jm32809g
2012
Cited 103 times
A mechanistic investigation of mechanochromic luminescent organoboron materials
Mechanochromic luminescence (ML) refers to the luminescence color and/or intensity change of solid-state materials induced by mechanical perturbations. For organic molecular solids, this phenomenon is related to the specific packing modes and orientations of individual fluorophores, which could give rise to different excited-state interactions. The molecular solids of difluoroboron dibenzoylmethane (BF2dbm) derivatives were previously found to exhibit reversible ML at room temperature and are promising as self-healing optical materials. In this report, we aim to shed some light on the mechanism of BF2dbm ML by trying to understand the excited-state interactions among solid-state BF2dbm molecules and elucidate how these interactions change upon mechanical stimulation. We first investigated the optical properties of monomeric, dimeric, and polymeric BF2dbm derivatives in optically dilute solutions and demonstrated unambiguously that BF2dbm moieties have a propensity to form H-aggregates. Next, we studied the physical properties of these boron complexes in the solid state including their crystal structures, fluorescence emissions, and mechanochromic luminescence. By correlating solution data with the solid-state characterization results, it was concluded that two coupled processes, force-induced emissive H-aggregate formation and energy transfer to the emissive H-aggregates, are responsible for the observed BF2dbm ML in the solid state.
DOI: 10.1016/j.ijmachtools.2014.10.007
2015
Cited 103 times
Molecular dynamics modelling of brittle–ductile cutting mode transition: Case study on silicon carbide
The mechanism of brittle–ductile cutting mode transition has received much attention over the past two decades. Due to the difficulties in directly observing the cutting zone during the brittle–ductile cutting mode transition by experimental techniques, many molecular dynamics (MD) studies have been conducted to investigate the atomicscale details of the phenomena, e.g. phase transformation, stress distribution and crack initiation, mostly under nanoscale undeformed chip thicknesses. A research gap is that direct MD modelling of the transition under practical undeformed chip thicknesses was not achieved in previous studies, due to the limitations in both computation capability and interaction potential. Important details of the transition under practical undeformed chip thicknesses thereby remain unclear, e.g. the location of crack formation and the stress distribution. In this study, parallel MD codes based on graphics processing units (GPU) are developed to enable large-scale MD simulations with multi-million atoms. In addition, an advanced interaction potential which reproduces brittle fracture much more accurately is adopted. As a result, the direct MD simulation of brittle–ductile cutting mode transition is realised for the first time under practical undeformed chip thicknesses. The MD-modelled critical undeformed chip thickness is verified by a plunge cutting experiment. The MD modelling shows that tensile stress exists around the cutting zone and increases with undeformed chip thickness, which finally induces brittle fractures. The location of crack formation and direction of propagation varies with undeformed chip thickness in the MD simulations, which agrees with the surface morphologies of the taper groove produced by the plunge cutting experiment. This study contributes significantly to the understanding of the details involved in the brittle–ductile cutting mode transition.
DOI: 10.1016/j.resconrec.2010.05.016
2011
Cited 102 times
Optimal production and pricing policy for a closed loop system
A closed loop system is investigated, in which the manufacturer has two channels to satisfy the demand: manufacturing brand-new products and remanufacturing returns into as-new products. Remanufactured products have no difference from brand-new products and can be sold in the same market at the same price. The demand is uncertain and sensitive to the selling price, while the return is also stochastic and sensitive to the acquisition price of used products. A mathematical model is developed to maximize the overall profit of the system by simultaneously determining the selling price, the production quantities for brand-new products and remanufactured products, and the acquisition price of used products. Some properties of the problem are analyzed, based on which a solution procedure is presented. Through a numerical example, the impacts of the uncertainties of both demand and return on the production plan, selling price, and the acquisition price of used products are analyzed.
DOI: 10.1016/j.applthermaleng.2020.115747
2020
Cited 101 times
Durability of phase-change-material module and its relieving effect on battery deterioration during long-term cycles
Phase change material cooling is now a hotspot in the field of battery thermal management. However, for promoting the practical application, the long-term durability of the phase change material module requires further evaluation, and thus, its relieving effect on the performance-deterioration of the battery module can be analyzed to further optimize the cooling structure of the actual battery packs. In this study, we investigate the thermo-electrochemical performance of a battery module with phase change material cooling for 200 cycles. The results show that after coupling with phase change material cooling, the temperature and temperature gradient of the module can be reduced to a large extent, for example, an obvious decrease of the maximum temperature from 51.7 to 47.5 °C at the 200th cycle. Thus, the cycle life can be prolonged by 65.3% compared with that of the module without phase change material. After systematically analyzing the internal resistance, impedance and micro/crystal structure of the electrodes in the cell, the relieving effect of the phase change material cooling on the performance deterioration can be attributed to the alleviation of the cell inconsistency and the cathode destruction during the long-term cycles.
DOI: 10.1016/j.oceaneng.2020.108179
2020
Cited 101 times
Finite-time extended state observer based nonsingular fast terminal sliding mode control of autonomous underwater vehicles
In this paper, a finite-time extended state observer-based nonsingular fast terminal sliding mode control (NFTSMC) is proposed for the trajectory tracking of autonomous underwater vehicles (AUVs) with various hydrodynamic uncertainties and external disturbances. First, a proportional–integral velocity variable based third-order fast finite-time extended state observer is designed to estimate the lumped uncertainties and their first derivatives. The concepts of finite-time stability and a new proposition are utilized to prove the finite-time uniformly ultimately boundness of the proposed observer. Then, based on the disturbance estimation, an NFTSMC is developed for AUVs. The inverse tangent function and linear control term are used to provide robustness against estimation error and avoid chattering in the thrusters. The position and attitude trajectories are proved to be fast finite-time stable via the Lyapunov theorem. To verify the theoretical analysis, comparative numerical simulations are provided to demonstrate the effectiveness of the proposed control scheme.
DOI: 10.1016/j.applthermaleng.2018.10.061
2019
Cited 99 times
Experiment and simulation for pouch battery with silica cooling plates and copper mesh based air cooling thermal management system
Battery thermal management has attracted increasing attention from scientists and engineers. An entire battery thermal management system is expensive and complex. In this regard, a battery thermal management system with air cooling is an effective solution. This paper proposes a battery thermal management system that uses double silica cooling plate coupled with copper mesh as the air cooling system. Experiments and simulations were conducted to investigate the cooling capacity of battery thermal management system coupled with copper mesh and determine the thickness of the silica cooling plate, air velocity, air inlet position, and number of fans. Results indicated that 1.5 mm-thick silica cooling plate and 3.5 m/s air velocity exhibited the optimal effect on thermal management. Furthermore, the thermal management system coupled with copper mesh exhibited an excellent battery performance. In addition, the forced convection effect of the designing equipment was evaluated. The number of fans had no significant influence on cooling ability. However, the fan at the front side of the battery presented better thermal management performance than that at the side of the battery. Moreover, the average temperature of five batteries using a 1.5 mm double silica cooling plate coupled with copper mesh was determined through simulation with 5 m/s forced convection speed during the 5C discharge process. The mean temperature was 2.87 °C higher than that of one battery condition. Hence, the battery thermal management system using double silica cooling plate coupled with copper mesh could be an effective and appropriate air cooling system for thermal management.
DOI: 10.1080/00207543.2012.693643
2013
Cited 96 times
A three-stage model for closed-loop supply chain configuration under uncertainty
Abstract In this paper, a general closed-loop supply chain (CLSC) network is configured which consists of multiple customers, parts, products, suppliers, remanufacturing subcontractors, and refurbishing sites. We propose a three-stage model including evaluation, network configuration, and selection and order allocation. In the first stage, suppliers, remanufacturing subcontractors, and refurbishing sites are evaluated based on a new quality function deployment (QFD) model. The proposed QFD model determines the relationship between customer requirements, part requirements, and process requirements. In addition, the fuzzy sets theory is utilised to overcome the uncertainty in the decision-making process. In the second stage, the closed-loop supply chain network is configured by a stochastic mixed-integer nonlinear programming model. It is supposed that demand is an uncertain parameter. Finally in the third stage, suppliers, remanufacturing subcontractors, and refurbishing sites are selected and order allocation is determined. To this end, a multi-objective mixed-integer linear programming model is presented. An illustrative example is conducted to show the process. The main novel innovation of the proposed model is to consider the CLSC network configuration and selection process simultaneously, under uncertain demand and in an uncertain decision-making environment. Keywords: reverse logistics (RL)closed-loop supply chain (CLSC)uncertaintymixed-integer nonlinear programming (MINLP)fuzzy sets theory (FST) Acknowledgments The work of the authors is supported by an NSERC Discovery grant. The first author thanks the Government of Ontario for an OGS.
DOI: 10.1016/j.jpowsour.2020.229116
2020
Cited 96 times
Experimental investigation of the flame retardant and form-stable composite phase change materials for a power battery thermal management system
An efficient battery thermal management system (BTMS) will undoubtedly promote the performance and lifespan of battery packs. In this study, a novel flame-retarded composite PCMs composed by paraffin (PA), expanded graphite (EG), ammonium polyphosphate (APP), red phosphorus (RP) and epoxy resin (ER) has been proposed for battery module. The thermophysical and flame retardant properties are investigated at both macro and micro levels. The results show that the proposed composite PCMs with an APP/RP ratio of 23/10 exhibit the optimum flame retardant performance. Besides, the APP/RP-based composite PCMs for 18,650 ternary battery module has also been researched comparing with air cooled and PCM with pure PA modes. The experimental results indicated that the fire retardant PCMs shown significant cooling and temperature balancing advantages for battery module, leading to a 44.7% and 30.1% reduction rate of the peak temperature and the maintenance of the maximum temperature difference within 1.36 °C at a 3 C discharge rate for 25 °C. Even at 45 °C, the temperature uniformity can still be controlled within 5 °C. Thus, this research indicates the composite PCM had good flame retardant and form stable properties, it would be utilized in BTMS, energy storage and other fields.
DOI: 10.15585/mmwr.mm6547a2
2016
Cited 95 times
Progress with Scale-Up of HIV Viral Load Monitoring — Seven Sub-Saharan African Countries, January 2015–June 2016
The World Health Organization (WHO) recommends viral load testing as the preferred method for monitoring the clinical response of patients with human immunodeficiency virus (HIV) infection to antiretroviral therapy (ART) (1). Viral load monitoring of patients on ART helps ensure early diagnosis and confirmation of ART failure and enables clinicians to take an appropriate course of action for patient management. When viral suppression is achieved and maintained, HIV transmission is substantially decreased, as is HIV-associated morbidity and mortality (2). CDC and other U.S. government agencies and international partners are supporting multiple countries in sub-Saharan Africa to provide viral load testing of persons with HIV who are on ART. This report examines current capacity for viral load testing based on equipment provided by manufacturers and progress with viral load monitoring of patients on ART in seven sub-Saharan countries (Côte d'Ivoire, Kenya, Malawi, Namibia, South Africa, Tanzania, and Uganda) during January 2015-June 2016. By June 2016, based on the target numbers for viral load testing set by each country, adequate equipment capacity existed in all but one country. During 2015, two countries tested >85% of patients on ART (Namibia [91%] and South Africa [87%]); four countries tested <25% of patients on ART. In 2015, viral suppression was >80% among those patients who received a viral load test in all countries except Côte d'Ivoire. Sustained country commitment and a coordinated global effort is needed to reach the goal for viral load monitoring of all persons with HIV on ART.
DOI: 10.1016/j.oceaneng.2018.08.020
2018
Cited 95 times
Adaptive cooperative formation control of autonomous surface vessels with uncertain dynamics and external disturbances
This paper investigates the leader-follower cooperative formation control problem of autonomous surface vessels (ASVs) with uncertain dynamics and external disturbances. Especially, ASVs can communicate with each other under a directed interaction topology. Based on directed graph theories, backstepping and the minimal learning parameter (MLP) algorithm, a novel distributed robust formation controller with two different adaptive laws is developed for each ASV. Dynamic surface control (DSC) is utilized to eliminate repeated derivative of virtual control laws, which is important to generate real-time control signals. Neural networks (NNs) approximation combined with an MLP-based adaptive law is incorporated into the proposed controller to enhance the robustness against model uncertainties. Then only one learning parameter instead of the enormous weights matrix is estimated for each ASV. An auxiliary adaptive law is designed to obtain a continuous controller when compensating approximation errors and disturbances. It is shown that desired formation shapes can be achieved with the proposed controller if the interaction topology has a directed spanning tree, and formation errors are guaranteed to be semi-global uniformly ultimately bounded (SGUUB). Simulations and comparison results are provided to illustrate the effectiveness of theoretical results.
DOI: 10.1007/s11071-018-4374-z
2018
Cited 93 times
Robust adaptive formation control of underactuated autonomous surface vessels based on MLP and DOB
DOI: 10.1016/j.biomaterials.2013.06.042
2013
Cited 90 times
The eradication of breast cancer cells and stem cells by 8-hydroxyquinoline-loaded hyaluronan modified mesoporous silica nanoparticle-supported lipid bilayers containing docetaxel
Breast cancer stem cells (BCSCs), which can fully recapitulate the tumor origin and are often resistant to chemotherapy and radiotherapy, are currently considered as a major obstacle for breast cancer treatment. To achieve the goal of both targeting BCSCs and bulk breast cancer cells, we developed 8-hydroxyquinoline-loaded hyaluronan modified mesoporous silica nanoparticles (MSN)-supported lipid bilayers (HA-MSS) and docetaxel-loaded MSS. The results showed that the size of all the nanoparticles was smaller than 200 nm. BCSCs were enriched from MCF-7 cells by a sphere formation method and identified with the CD44+/CD24− phenotype. Quantitative and qualitative analysis demonstrated that HA promotes the uptake of HA-MSS in CD44-overexpressing MCF-7 mammospheres, revealing the mechanism of receptor-mediated endocytosis. DTX or DTX-loaded MSS showed much enhanced cytotoxicity against MCF-7 cells compared with MCF-7 mammospheres, whereas 8-HQ or 8-HQ-loaded HA-MSS showed much enhanced cytotoxicity against MCF-7 mammospheres compared with MCF-7 cells. In the MCF-7 xenografts in mice, the combination therapy with DTX-loaded MSS plus 8-HQ-loaded HA-MSS produced the strongest antitumor efficacy, with little systemic toxicity (reflecting by loss of body weight) in mice. Thus, this combination therapy may provide a potential strategy to improve the therapy of breast cancer by eradication of breast cancer cells together with BCSCs.
DOI: 10.1016/j.carbon.2014.05.030
2014
Cited 89 times
Preparation and lithium-storage performance of carbon/silica composite with a unique porous bicontinuous nanostructure
A class of carbon/silica composite with a porous bicontinuous nanostructure is prepared via a simple sol–gel method and then used as anode material for lithium-ion batteries. The reversible specific capacity of the as-prepared composite stays over 560 mAh g−1 after 30 cycles, much higher than that of many other carbon materials including commercial graphite and carbon/silica composites. The good electrochemical performance can be ascribed to the following three factors: (i) continuous silica gel framework stores most of lithium ions; (ii) continuous carbon framework not only restrains the volume change during repeated insertion and extraction of lithium ions, but also represents an excellent conductive skeleton throughout the composite; (iii) nanopores among the carbon/silica bicontinuous framework are helpful to the mass transport and can further buffer the volume change of silica.
DOI: 10.1021/ja512569m
2015
Cited 86 times
Enantioselective Fluorescent Recognition in the Fluorous Phase: Enhanced Reactivity and Expanded Chiral Recognition
A novel perfluoroalkyl-BINOL-based chiral diketone is found to be the first highly enantioselective fluorescent sensor in the fluorous phase. One enantiomer of a chiral amino alcohol or diamine at a concentration greater than 1 mM can cause an up to 1200-2000-fold fluorescent enhancement of the sensor (0.08 mM), while the other enantiomer gives only a 10-50-fold enhancement. The fluorous-phase-based sensor is found to enhance the reactivity of the previously reported fluorous insoluble sensor with amino alcohols and expand its chiral recognition ability. Dynamic light scattering studies show the formation of aggregates of very different particle sizes when two enantiomers of a substrate interact with the sensor in perfluorohexane (FC-12). This substantial difference enables easy discrimination of the enantiomers with UV-lamps or even the naked eye. NMR, IR, and mass spectroscopic studies indicate that the fluorescent enhancement and enantioselectivity should originate from the fluorous solvent-promoted nucleophilic addition of the amino alcohols to the carbonyl groups of the sensor.
DOI: 10.1002/2016jd025154
2016
Cited 85 times
Estimating daily air temperatures over the Tibetan Plateau by dynamically integrating MODIS LST data
Abstract Recently, remotely sensed land surface temperature (LST) data have been used to estimate air temperatures because of the sparseness of station measurements in remote mountainous areas. Due to the availability and accuracy of Moderate Resolution Imaging Spectroradiometer (MODIS) LST data, the use of a single term or a fixed combination of terms (e.g., Terra/Aqua night and Terra/Aqua day), as used in previous estimation methods, provides only limited practical application. Furthermore, the estimation accuracy may be affected by different combinations and variable data quality among the MODIS LST terms and models. This study presents a method that dynamically integrates the available LST terms to estimate the daily mean air temperature and simultaneously considers model selection, data quality, and estimation accuracy. The results indicate that the differences in model performance are related to the combinations of LST terms and their data quality. The spatially averaged cloud cover of ~14% for the developed product between 2003 and 2010 is much lower than the 35–54% for single LST terms. The average cross‐validation root‐mean‐square difference values are approximately 2°C. This study identifies the best LST combinations and statistical models and provides an efficient method for daily air temperature estimation with low cloud blockage over the Tibetan Plateau (TP). The developed data set and the method proposed in this study can help alleviate the problem of sparse air temperature data over the TP.
DOI: 10.1017/jog.2019.13
2019
Cited 85 times
Glacial lake evolution and glacier–lake interactions in the Poiqu River basin, central Himalaya, 1964–2017
ABSTRACT Despite previous studies, glacier–lake interactions and future lake development in the Poiqu River basin, central Himalaya, are still not well understood. We mapped glacial lakes, glaciers, their frontal positions and ice flow from optical remote sensing data, and calculated glacier surface elevation change from digital terrain models. During 1964–2017, the total glacial-lake area increased by ~110%. Glaciers retreated with an average rate of ~1.4 km 2 a −1 between 1975 and 2015. Based on rapid area expansion (&gt;150%), and information from previous studies, eight lakes were considered to be potentially dangerous glacial lakes. Corresponding lake-terminating glaciers showed an overall retreat of 6.0 ± 1.4 to 26.6 ± 1.1 m a −1 and accompanying lake expansion. The regional mean glacier elevation change was −0.39 ± 0.13 m a −1 while the glaciers associated with the eight potentially dangerous lakes lowered by −0.71 ± 0.05 m a −1 from 1974 to 2017. The mean ice flow speed of these glaciers was ~10 m a −1 from 2013 to 2017; about double the mean for the entire study area. Analysis of these data along with climate observations suggests that ice melting and calving processes play the dominant role in driving lake enlargement. Modelling of future lake development shows where new lakes might emerge and existing lakes could expand with projected glacial recession.
DOI: 10.2147/dddt.s137507
2017
Cited 84 times
Schisandrin B attenuates CCl&lt;span style="font-size: 8.33333px"&gt;4&lt;/span&gt;-induced liver fibrosis in rats by regulation of Nrf2-ARE and TGF-&amp;beta;/Smad signaling pathways
Liver fibrosis is a major pathological feature of chronic liver diseases and there is no effective therapy program at present.Schisandrin B (Sch B) is the major bioactive ingredient of Schisandra chinensis, with antioxidative, anti-inflammatory, antitumor, and hepatoprotective properties.This study aimed to investigate the protective effect and related molecular mechanism of Sch B against carbon tetrachloride (CCl 4 )-induced liver fibrosis in rats.The in vivo therapeutic effect of Sch B on liver fibrosis induced by CCl 4 was examined in rats.In vitro, rat hepatic stellate cells (HSC-T6) were used to assess the effect of Sch B on the activation of HSCs.Sch B effectively attenuated liver damage and progression of liver fibrosis in rats, as evidenced by improved liver function and decreased collagen deposition.The effects of Sch B were associated with attenuating oxidative stress by activating nuclear factor-erythroid 2-related factor 2 (Nrf2)-mediated antioxidant signaling and suppressing HSC activation by inhibiting the transforming growth factor-β (TGF-β)/Smad signaling pathway.In an in vitro study, it was shown that Sch B inhibited TGFβ-induced HSC activation.Finally, Sch B significantly inhibited TGF-β1-stimulated phosphorylation of Smad and signaling of mitogen-activated protein kinases.This study demonstrates that Sch B prevents the progression of liver fibrosis by the regulation of Nrf2-ARE and TGF-β/Smad signaling pathways, and indicates that Sch B can be used for the treatment of liver fibrosis.
DOI: 10.1016/j.scitotenv.2018.10.128
2019
Cited 84 times
Ground-based evaluation of MODIS snow cover product V6 across China: Implications for the selection of NDSI threshold
The new MODIS daily NDSI snow cover product version 6 (V6) is released to replace V5 with significant revisions. This study evaluates, for the first time, the accuracy of product V6 across China based on daily snow-depth measurements during 2003-2013 from 279 and 252 stations for Terra and Aqua, respectively. Three schemes of selecting NDSI thresholds for Terra and Aqua were tested and compared including: (1) the locally optimal NDSI threshold, (2) the minimum valid NDSI of 0.1, and (3) the global reference NDSI threshold of 0.4. The mean Cohen's Kappa (CK) of the optimal, minimum and global reference thresholds for Terra (Aqua) are 0.80 (0.60), 0.77 (0.58), 0.72 (0.51), respectively, while snow depth ≥ 1 cm. The NDSI threshold of 0.1 is demonstrated to be more reasonable than the threshold of 0.4 for use in China. This is also supported by the accuracy comparison conducted for the clear-day snow-cover day calculation. Terra V6 and Terra V5 have comparable accuracies whereas Aqua V6 shows better accuracy than Aqua V5 does. The revised temperature screen algorithm employed in V6 is found to be problematic with large snow commission errors in high altitude stations. Regionally, product V6 presents low CKs of 0.61 and 0.35 for the optimal thresholds of Terra and Aqua in the Tibetan Plateau, which are attributed to its high elevation and relatively small snow depth. This study provides practical implications for use of MODIS snow cover production V6 in China.
DOI: 10.1016/j.isatra.2019.04.035
2019
Cited 84 times
Adaptive output-feedback control with prescribed performance for trajectory tracking of underactuated surface vessels
In this paper, we address the problem of trajectory tracking control of underactuated surface vessels in a quantitative method with only position and attitude available. Combined with high-gain observer, parameter compression algorithm and performance function, an adaptive control scheme with prescribed performance is proposed. The high-gain observer is constructed to estimate the velocities, and the parameter compression algorithm is adopted to address persistent perturbations and model uncertainties in a more concise way. By prescribed performance function, the controller can be designed with prescribed performance. The results about system stability is given and proved by using the Lyapunov direct method. The signals concerning with all the errors converge to a bounded set. Compared with the existing methods, the developed scheme can reduce the number of tuning parameters, and guarantee the tracking errors bounded within the prescribed performance constraints in the transformed coordinate, which means the steady errors, convergence rates and maximum overshoots can be guaranteed by the performance function. Comparison and numerical simulations are given to demonstrate the effectiveness of the proposed scheme.
DOI: 10.1021/acsnano.8b01508
2018
Cited 82 times
Hierarchical Multiplexing Nanodroplets for Imaging-Guided Cancer Radiotherapy via DNA Damage Enhancement and Concomitant DNA Repair Prevention
Clinical success of cancer radiotherapy is usually impeded by a combination of two factors, i.e., insufficient DNA damage and rapid DNA repair during and after treatment, respectively. Existing strategies for optimizing the radiotherapeutic efficacy often focus on only one facet of the issue, which may fail to function in the long term trials. Herein, we report a DNA-dual-targeting approach for enhanced cancer radiotherapy using a hierarchical multiplexing nanodroplet, which can simultaneously promote DNA lesion formation and prevent subsequent DNA damage repair. Specifically, the ultrasmall gold nanoparticles encapsulated in the liquid nanodroplets can concentrate the radiation energy and induce dramatic DNA damage as evidenced by the enhanced formation of γ-H2AX foci as well as in vivo tumor growth inhibition. Additionally, the ultrasound-triggered burst release of oxygen may relieve tumor hypoxia and fix the DNA radical intermediates produced by ionizing radiation, prevent DNA repair, and eventually result in cancer death. Finally, the nanodroplet platform is compatible with fluorescence, ultrasound, and magnetic resonance imaging techniques, allowing for real-time in vivo imaging-guided precision radiotherapy in an EMT-6 tumor model with significantly enhanced treatment efficacy. Our DNA-dual-targeting design of simultaneously enhancing DNA damage and preventing DNA repair presents an innovative strategy to effective cancer radiotherapy.
DOI: 10.1021/acsami.9b00856
2019
Cited 82 times
Enhanced Performance of a CVD MoS<sub>2</sub> Photodetector by Chemical in Situ n-Type Doping
Transition metal dichalcogenides (TMDs) are a category of promising two-dimensional (2D) materials for the optoelectronic devices, and their unique characteristics include tunable band gap, nondangling bonds as well as compatibility to large-scale fabrication, for instance, chemical vapor deposition (CVD). MoS2 is one of the first TMDs that is well studied in the photodetection area widely. However, the low photoresponse restricts its applications in photodetectors unless the device is applied with ultrahigh source-drain voltage ( VDS) and gate voltage ( VGS). In this work, the photoresponse of a MoS2 photodetector was improved by a chemical in situ doping method using gold chloride hydrate. The responsivity and specific detectivity were increased to 99.9 A/W and 9.4 × 1012 Jones under low VDS (0.1 V) and VGS (0 V), which are 14.6 times and 4.8 times higher than those of a pristine photodetector, respectively. The photoresponse enhancement results from chlorine n-type doping in CVD MoS2 which reduces the trapping of photoinduced electrons and promotes the photogating effect. This novel doping strategy leads to great applications of high-performance MoS2 photodetectors potentially and opens a new avenue to enhance photoresponse for other 2D materials.
DOI: 10.1038/s41598-017-00535-8
2017
Cited 81 times
The gene expression profiles in response to 102 traditional Chinese medicine (TCM) components: a general template for research on TCMs
Traditional Chinese medicines (TCMs) have important therapeutic value in long-term clinical practice. However, because TCMs contain diverse ingredients and have complex effects on the human body, the molecular mechanisms of TCMs are poorly understood. In this work, we determined the gene expression profiles of cells in response to TCM components to investigate TCM activities at the molecular and cellular levels. MCF7 cells were separately treated with 102 different molecules from TCMs, and their gene expression profiles were compared with the Connectivity Map (CMAP). To demonstrate the reliability and utility of our approach, we used nitidine chloride (NC) from the root of Zanthoxylum nitidum, a topoisomerase I/II inhibitor and α-adrenoreceptor antagonist, as an example to study the molecular function of TCMs using CMAP data as references. We successfully applied this approach to the four ingredients in Danshen and analyzed the synergistic mechanism of TCM components. The results demonstrate that our newly generated TCM data and related methods are valuable in the analysis and discovery of the molecular actions of TCM components. This is the first work to establish gene expression profiles for the study of TCM components and serves as a template for general TCM research.