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Improved Na storage and Coulombic efficiency in TiP_(2)O_(7)@C microflowers for sodium ion batteries

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Nano Research 2021年第1期14卷 139-147页

作者： jun Pan Nana Wang lili li Feng Zhang Zhenjie Cheng Yanlu li Jian Yang Yitai qian Key Laboratory of Colloid and Interface Chemistry Ministry of EducationSchool of Chemistry and Chemical EngineeringShandong UniversityJinan 250100China Shenzhen Research Institute of Shandong University Shenzhen 518000China Institute for Superconducting and Electronic Materials Australian Institute for Innovative MaterialsUniversity of Wollongong Innovation CampusNorth Wollongong New South Wales 2500Australia State Key Lab of Crystal Materials Shandong UniversityJinan 250100China

Ti-based anode materials in sodium ion batteries have attracted extensive interests due to its abundant resources,low toxicity,easy synthesis and long cycle ***,low Coulombic efficiency and limited specific capacity affect their ***,cubic-phase TiP_(2)O_(7)is examined as anode materials,using in-situ/ex-situ characterization *** is concluded that the redox reactions of Ti4^(+)/Ti^(3+)and Ti^(3+)/Ti^(0)consecutively occur during the discharge/charge processes,both of which are highly *** reactions make the specific capacity of TiP_(2)O_(7)even higher than the case of TiO2 that only contains a simple anion,0^(2-).Interestingly,Ti species participate only one of the redox reactions,due to the remarkable difference in local structures related to the sodiation *** stable discharge/charge products in TiP_(2)O_(7)reduce the side reactions and improve the Coulombic efficiency as compared to T *** features make it a promising Ti-based anode for sodium ion ***,TiP_(2)O_(7)@C microflowers exhibit excellent electrochemical performances,〜109 mAh·g^(-1)after 10,000 cycles at 2 A·g^(-1),or 95.2 mAh·g^(-1)at 10 A·g^(-1).The results demonstrate new opportunities for advanced Ti-based anodes in sodium ion batteries.

关键词： TiP_(2)O_(7) electrochemical reactions anodes sodium ion batteries

Synthesis and Characterization of Cobalt-Carbon Core-Shell Microspheres in Supercritical Carbon Dioxide System

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Chinese Journal of Chemical Physics 2008年第1期21卷 76-80页

作者： jun-song Yang qian-wang Chen Hefei National Laboratory for Physical Sciences at Microscale Department of Materiab Science andEngineering Department of Chemisto4 University of Science and Technology of China Hefei 230025China

The synthesis of cobalt-carbon core-shell microspheres in supercritical carbon dioxide system was investi- gated. Cobalt-carbon core-shell microspheres with diameter of about 1μm were prepared at 350 ℃ for 12 h in a closed vessel containing an appropriate amount of bis（cyclopentadienyl）cobalt powder and dry ice. Characterization by a variety of techniques, including X-ray powder diffraction, X-ray photoelectron spectroscopy, TransmissiOn electron microscope, Fourier transform infrared spectrum and Raman spectroscopy analysis reveals that each cobalt-carbon core-shell microsphere is made up of an amorphous cobalt core with diameter less than 1 μm and an amorphous carbon shell with thickness of about 200 nm. The possible growth mechanism of cobalt-carbon core-shell microspheres is discussed, based on the pyrolysis of bis（cyclopentadienyl）cobalt in supercritical carbon dioxide and the deposition of carbon or carbon clusters with odd electrons on the surface of magnetic cobalt cores due to magnetic attraction. Magnetic measurements show 141.41 emu/g of saturation magnetization of a typical sample, which is lower than the 168 emu/g of the corresponding metal cobalt bulk material. This is attributed to the considerable mass of the carbon shell and amorphous nature of the magnetic core. Control of magnetism in the cobalt-carbon core-shell microspheres was achieved by annealing treatments.

关键词： Cobalt-carbon core-shell microspheres Supercritical carbon dioxide system

Energy Spectrum of a Bipartite Complicated-Coupled-Oscillator System

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Communications in Theoretical Physics 2006年第3期45卷 425-428页

作者： PANG qian-jun Physics Department Shanghai Jiao Tong University Shanghai 2000307 China

We present a general discussion on the eigenstate problem of a bipartite complicated-coupled-oscillator system. By use of a generalized intermediate entangled state representation, the eigenvalue and eigenfunction of Hamiltonian are analytically obtained. As its application, we obtain the energy spectrum for two special situations of Hamiltonian.

关键词： generalized intermediate entangled state bipartite coupled oscillator

Application of Coordinate-Momentum Intermediate Representation in Solving Eigenstate Problem of a Coupled Oscillator System

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Communications in Theoretical Physics 2005年第3X期44卷 440-444页

作者： PANG qian-jun Department of Physics Shanghai Jiao Tong University Shanghai 200030 China

We study the eigenstate problem of a kind of coupled oscillators in the new quantum mechanical representation ｜q,μ,υ〉, which is defined as the eigenvector of the operator （μQ ＋ υP）, whereμ and υ are two real parameters. We also use the U operator transformation method to deal with the same problem. We obtain the normally ordered product expressions of U operator and eigenvector. It is shown that the ground state of system Hamiltonian is a squeezed state.

关键词： coordinator-momentum intermediate representation coupled oscillator operator transformation method

Spatio-temporal variation of spring phenology in Tibetan Plateau and its linkage to climate change from 1982 to 2012

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Journal of Mountain Science 2016年第1期13卷 83-94页

作者： DING Ming-jun li Lan-hui NIE Yong CHEN qian ZHANG Yi-li Key Laboratory of Poyang Lake Wetland and Watershed Research Ministry of Education and School of Geography and EnvironmentJiangxi Normal UniversityNanchang 330022China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of SciencesBeijing 100101China Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China

The influence of climate change on vegetation phenology is a heated issue in current climate change *** used GIMMS-3g NDVI data to detect the spatio-temporal dynamics of the start of the growing season(SGS) over the Tibetan Plateau(TP) from 1982 to 2012 and to analyze its relationship with temperature and *** significant trend was observed in the SGS at the regional scale during the study period(R^2 = 0.03,P = 0.352).However,there were three time periods(1982-1999,1999-2008 and 2008-2012) with identifiable,distinctly different *** with a significant advancing trend were mainly scattered throughout the humid and semi-humid areas,whereas the regions with a significant delaying trend were mostly distributed throughout the semi-arid *** analysis showed that the response of the SGS to climate change varies *** SGS was significantly correlated with the spring temperature and the start of the thermal growth season(STGS) in the relatively humid *** increasing aridity,theimportance of the spring temperature for the SGS gradually ***,the influences of precipitation and winter temperature on the SGS were complicated across the plateau.

关键词： Spring phenology Spatial pattern Temporal variation Climate change CorrelationTibetan Plateau (TP)

A fully solid-state cold thermal energy storage device for car seats using shape-memory alloys

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Frontiers in Energy 2023年第4期17卷 504-515页

作者： Yian LU Suxin qian jun SHEN Department of Refrigeration and Cryogenic Engineering Xi’an Jiaotong UniversityXi’an710049China Key Laboratory of Cryogenics Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing100190China Department of Energy and Power Engineering School of Mechanical EngineeringBeijing Institute of TechnologyBeijing100081China

Thermal energy storage has been a pivotal technology to fill the gap between energy demands and energy *** a solid-solid phase change material,shape-memory alloys(SMAs)have the inherent advantages of leakage free,no encapsulation,negligible volume variation,as well as superior energy storage properties such as high thermal conductivity(compared with ice and paraffin)and volumetric energy density,making them excellent thermal energy storage *** these characteristics,the design of the shape-memory alloy based the cold thermal energy storage system for precooling car seat application is introduced in this paper based on the proposed shape-memory alloy-based cold thermal energy storage *** simulation results show that the minimum temperature of the metal boss under the seat reaches 26.2°C at 9.85 s,which is reduced by 9.8°C,and the energy storage efficiency of the device is 66%.The influence of initial temperature,elastocaloric materials,and the shape-memory alloy geometry scheme on the performance of car seat cold thermal energy storage devices is also *** SMAs are both solid-state refrigerants and thermal energy storage materials,hopefully the proposed concept can promote the development of more promising shape-memory alloy-based cold and hot thermal energy storage devices.

关键词： shape-memory alloy(SMA) elastocaloric effect(eCE) cooled seat cold thermal energy storage

Microbial community dynamics during composting of animal manures contaminated with arsenic,copper,and oxytetracycline

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Journal of Integrative Agriculture 2021年第6期20卷 1649-1659页

作者： Ebrahim SHEHATA CHENG Deng-miao MA qian-qian li Yan-li liU Yuan-wang FENG Yao JI Zhen-yu li Zhao-jun Key Laboratory of Plant Nutrition and Fertilizer Ministry of Agriculture and Rural Affairs/China-New Zealand Joint Laboratory for Soil Molecular EcologyInstitute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijing 100081P.R.China Department of Natural Resources and Agricultural Engineering College of AgricultureDamanhour UniversityDamanhour 22511Egypt Research Center for Eco-Environmental Engineering Dongguan University of TechnologyDongguan 523808P.R.China

Effects of the heavy metal copper(Cu), the metalloid arsenic(As), and the antibiotic oxytetracycline(OTC) on bacterial community structure and diversity during cow and pig manure composting were investigated. Eight treatments were applied, four to each manure type, namely cow manure with:(1) no additives(control),(2) addition of heavy metal and metalloid,(3) addition of OTC and(4) addition of OTC with heavy metal and metalloid;and pig manure with:(5) no additives(control),(6) addition of heavy metal and metalloid,(7) addition of OTC and(8) addition of OTC with heavy metal and metalloid. After 35 days of composting, according to the alpha diversity indices, the combination treatment(OTC with heavy metal and metalloid) in pig manure was less harmful to microbial diversity than the control or heavy metal and metalloid treatments. In cow manure, the treatment with heavy metal and metalloid was the most harmful to the microbial community, followed by the combination and OTC treatments. The OTC and combination treatments had negative effects on the relative abundance of microbes in cow manure composts. The dominant phyla in both manure composts included Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria. The microbial diversity relative abundance transformation was dependent on the composting time. Redundancy analysis(RDA) revealed that environmental parameters had the most influence on the bacterial communities. In conclusion, the composting process is the most sustainable technology for reducing heavy metal and metalloid impacts and antibiotic contamination in cow and pig manure. The physicochemical property variations in the manures had a significant effect on the microbial community during the composting process. This study provides an improved understanding of bacterial community composition and its changes during the composting process.

关键词： composting heavy metal and metalloid oxytetracycline microbial community principle component analysis redundancy analysis

用密封容器实现新温度参考点——NaCl凝固点

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计量学报 1987年第3期 180-186页

作者：朱其俊钱丽娜靖英张世才徐红军刘玉环中国测试技术研究院金属研究所

800℃附近需要一个新的温度参考点,NaCl凝固点的位置适宜,但难于实现。现在采取了有效技术措施,以密封容器实现了NaCl凝固点。它的复现性在±6mK以内,具有足够长的温坪持续时间（2～3小时）,过冷度小于1℃。该参考点t68,NaCl为（802.12... 详细信息

800℃附近需要一个新的温度参考点,NaCl凝固点的位置适宜,但难于实现。现在采取了有效技术措施,以密封容器实现了NaCl凝固点。它的复现性在±6mK以内,具有足够长的温坪持续时间（2～3小时）,过冷度小于1℃。该参考点t68,NaCl为（802.12±0.034）℃,可作IPTS次级参考点。现已在温标非唯一性实验研究及高温铂电阻温度计分度中付诸应用。

关键词：参考点凝固点转变温度铂电阻温度计 NaCl

Molecular Dynamics Study of Ionic liquid Film Based on [emim][Tf2N] and [emiml[TfO] Adsorbed on Highly Oriented Pyrolytic Graphite

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Chemical Research in Chinese Universities 2013年第2期29卷 366-373页

作者： XUE Xiang-gui ZHAO li LU Zhong-yuan qian Hu-jun State Key Laboratory of Theoretical and Computational Chemistry Institute of Theoretical Chemistry Jilin University Changchun 130021 P. R. China College of life Science Jilin University Changchun 130012 P. R. China

Molecular dynamics simulation was used to study the ionic liquid（IL） crystalline film based on 1-ethyl-3-methylimidazolium bis[trifluoromethylsulfonyl]imide（[emim][Tf2N]） and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate（[emim][TfO]） on the graphite surface. Our results show that the cations are parallelly dis- tributed to the surface in the 1/2 monolayer（ML） crystalline film. The [Tf2N] anions are parallel to the surface with the oxygen atoms at the bottom, whereas the [TfO]- anions are perpendicularly distributed to the surface also with the oxygen atoms at the bottom in the 1/2 ML crystalline film. It has been found that the IL-vapor interface strongly in- fluences the arrangement of ions at the interface. The anions in the top layer with the oxygen atoms outmost turn over to make themselves with the F atoms outmost so as to form C--H...O hydrogen bonds with the cations. The calcu- lated orientational ordering shows that in the outmost layer at the IL-vapor interface, the cation rings present either oarallel or oernendicular to the surface at 350 K.

关键词： Ionic liquid Molecular dynamics simulation Graphite surface