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Unlocking iron-based mixed-phosphate cathode for sodium-ion batteries through off-stoichiometry

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Nano Research 2024年第9期17卷 8119-8125页

作者： Zhaolu Liu Yongjie Cao Ning Wang Hui Yang Hao Zhang Xinyue xu Nan Wang Jie xu Yao Liu Junxi Zhang Yongyao Xia Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power Shanghai University of Electric PowerShanghai 200090China department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Fudan UniversityShanghai 200433China School of Materials Science and Engineering Anhui University of TechnologyMa’anshan 243002China Key Laboratory of Interfacial Physics and technology Shanghai Institute of Applied PhysicsChinese Academy of SciencesShanghai 201800China

The off-stoichiometric iron-based phosphate(Na_(3.12)Fe_(2.44)(P_(2)O_(7))_(2),denoted as Na3.12)as a low cost and high structure stability cathode material has been widely studied for sodium-ion batteries(SIBs).However,the lower theoretical specific capacity(117 mAh·g^(-1))has seriously limited its practical *** this work,we incorporate varying proportion of sodium-iron phosphate(NaFePO_(4))into the Na3.12 to form a series of new high specific capacity mixed-phosphates Na_(3.12+x)Fe_(2.44+x)(P_(2)O_(7))_(2)(PO_(4))x cathode materials for *** optimizing the introduction amount of NaFePO_(4)into Na_(3.12),the practical reversible of Na_(3.12+x)Fe_(2.44+x)(P_(2)O_(7))_(2)(PO_(4))_(x) increased from 92 to 125.2 mAh·g^(-1).The nano-size Na5.12Fe4.44(P_(2)O_(7))_(2)(PO_(4))_(2) cathode material shows a reversible specific capacity of 125.2 mAh·g^(-1)at 0.1 C in *** at 60 C,it still exhibits a reversible specific capacity of 93.3 mAh·g^(-1)and keeps a capacity retention ratio of 87%after 3000 cycles at 20 ***,we present a novel approach to design a series of off-stoichiometric mixed-phosphates cathode materials for SIBs.

关键词： sodium-ion batteries cathode material iron-based mixed-phosphates off-stoichiometric

Progress of vegetation modelling and future research prospects

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Science china Earth Sciences 2024年第9期67卷 2718-2738页

作者： Siqi LI xu ZHANG Zhengyao LU Jian NI Jianhua LU State Key Laboratory of Tibetan Plateau Earth System Resources and Environment(TPESRE)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China British Antarctic Survey Cambridge CB30ETUnited Kingdom department of Physical Geography and Ecosystem Science Lund UniversityLund 22362Sweden College of Life Sciences Zhejiang Normal UniversityJinhua 321004China School of Atmospheric Sciences Sun Yat-sen University and Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519082China

Terrestrial vegetation is a crucial component of the Earth system,and its changes not only represent one of the most distinct aspects of climate change but also exert significant feedback within the climate system by exchanging energy,moisture,and carbon *** quantitatively and mechanistically study climate-vegetation feedback,numerical vegetation models have been developed on the theory of ecophysiological constraints on plant functional *** models eventually can simulate vegetation distribution and succession across different spatial and temporal scales,and associated terrestrial carbon cycle processes by categorizing vegetation into biomes according different plant functional types and their associated environmental *** we review the developing history of vegetation models and provide recent advances and future *** 21st century,static vegetation models,as developed statistical models,can only simulate equilibrated characteristics of vegetation *** last several decades,Dynamic Global Vegetation Models(DGVMs)have been developed to simulate instantaneous responses of vegetation to climate change and associated dynamics,and can be coupled with Earth system models to investigate interactions among atmosphere,ocean,and *** are also widely applied to investigate the dynamics accounting for changes in the geographic distribution patterns of land surface vegetation at different spatial and temporal scales and to assess the impacts of terrestrial carbon and water fluxes and land use *** suggest that future vegetation modeling could integrate with machine learning,and explore vegetation transient response and feedback as well as impacts of process hierarchies and human activities on climate and ecosystem.

关键词： Vegetation models DGVMs Ecosystems Plant functional types Plant functional traits

Aligned Solidification Structure of the MnBi Phase in Semisolidified Bi-Mn Alloy with a Static Magnetic Field

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Journal of Materials Science & technology 2004年第3期20卷 311-314页

作者： Zhongming REN Hui WANG Kang DENG Kuangdi xu department of Materials Science and Engineerng,Shanghai university,Shanghai 200072, china Dept. of Mat. Sci. and Eng. Shanghai Univ. Shanghai 200072 China

The solidification structure of Bi-3 wt pct Mn alloy grown up in the semisolid zone under the influence of a staticmagnetic field (up to 1.0 T) and the relation of the magnetic property with the solidification structure have beeninvestigated experimentally. It was shown that the primary phase MnBi crystals in the alloy aligned and oriented alongthe direction of the applied magnetic field. The orientating tendency and the average length of the elongated MnBicrystals increased with the increase of the applied field and the solidification time. Moreover, the remanence of thealloy along the aligned direction of the MnBi phase in the case of solidification with a magnetic field was apparentlyanisotropic and nearly double of that without the magnetic field. This indicated that the MnBi crystals orientedand aligned along their easy magnetization axis. A model was proposed to explain the alignment and orientationgrowth of the MnBi crystals in a magnetic field in terms of the magnetic anisotropy of the crystals and the magneticinteraction between them.

关键词： Magnetic field Bi-Mn alloy MnBi Solidification

The influence of stress-dependent overpotential on dendrite growth in all-solid-state battery with cracks

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Science china(Technological Sciences) 2024年第8期67卷 2493-2504页

作者： ZHANG ZhenHua ZHANG Yong LIU Chang HOU xu WANG Jie department of Engineering Mechanics School of Aeronautics and AstronauticsZhejiang UniversityHangzhou 310027China Zhejiang Laboratory Hangzhou 311100China Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province Zhejiang UniversityHangzhou 310027China School of Aerospace Engineering and applied Mechanics Tongji UniversityShanghai 200092China applied Mechanics and Structure Safety Key Laboratory of Sichuan Province School of Mechanics and Aerospace EngineeringSouthwest Jiaotong UniversityChengdu 610031China department of Industrial and Systems Engineering The Hong Kong Polytechnic UniversityHong Kong 999077China

Dendrite growth is one of the main challenges in maintaining the service life of all-solid-state lithium-ion *** stress has been reported to significantly affect dendrite *** this study,to explain the effect of mechanical stress on electrochemical reactions in all-solid-state batteries,a modified phase-field model for dendrite growth is proposed by considering the stress-dependent *** growth under different mechanical loadings in an all-solid-state battery is investigated using the proposed *** with previous experimental results,the current result shows that compressive stress inhibits dendrite *** the stress concentration at the tips of processing-induced microcracks,the effects of the number and distribution of microcracks on dendrite growth are *** results show that the stress-concentration field induced at the tips of cracks or voids can change the morphology of dendrites and decrease their growth *** study provides a new perspective for explaining Li dendrite growth under mechanical stress and offers inspiration for prolonging the service life of all-solid-state batteries based on defect and stress regulation,which may be further realized in experiments by filling solid electrolytes with different types of nanofillers.

关键词： Butler–Volmer equation stress-dependent overpotential microcracks all-solid-state battery phase-field simulation

Preparation of PFSA/PSf hollow fiber composite membranes with recovered PFSA for the pervaporation separation of EtOH/H_2O

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Science china Chemistry 2010年第1期53卷 273-280页

作者： LANG WanZhong1,2,TONG Wei2,xu ZhenLiang2 & GUO YaJun1 1department of Chemistry,Shanghai Normal university,Shanghai 200234,china 2Chemical Engineering Research Center,East china university of Science and technology,Shanghai 200237,china department of Chemistry Shanghai Normal University Shanghai China Chemical Engineering Research Center East China University of Science and Technology Shanghai China

Perfluorosulfonic acid/Polysulfone(PFSA/PSf) hollow fiber composite membranes have been prepared by dip-coating method using PSf ultrafiltration(UF) membrane as substrate with recovered *** composite membranes were applied to the pervaporation separation of 95% ethanol(EtOH)/H2O *** images show that the thickness of the PFSA skin layer of the composite membranes is about 2 μm,much thinner than those of other PFSA composite membranes revealed in the *** of annealing temperature,coating solution concentration and counter-ions of PFSA on the pervaporation performances of the composite membranes were *** total flux decreases and separation factor increases with the increase of annealing *** highest permeation flux of 3230 g m-2 h-1 and a separation factor of 5.4 is obtained for the composite membrane annealed at 80°*** lowest permeation flux of 396 g m-2 h-1 and a separation factor of 27.7 is obtained for the composite membrane annealed at 160°*** permeation performances of the PFSA/PSf composite membrane are evidently influenced by the counter-ions of *** flux sequence of the PFSA/PSf composite membranes with different counter-ions is H+>Li+>Ca2+>Mg2+>Na+>K+>Ba2+>Fe3+>Al3+,and the separation factor sequence is H+Na+>K+.There are very little variations of △Eapp values between the composite membranes with three divalent counterions(Mg2+,Ca2+ and Ba2+),and the △Eapp values of the composite membranes with two trivalent counterions(Fe3+ and Al3+) are relatively high.

关键词： pervaporation hollow fiber composite membrane perfluorslulfonic acid(PFSA) ethanol(EtOH)/H2O mixture

Electromagnetic fields in ultra-peripheral relativistic heavy-ion collisions

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Nuclear Science and Techniques 2024年第2期35卷 103-109页

作者： Jie Zhao Jin-Hui Chen xu-Guang Huang Yu-Gang Ma Key Laboratory of Nuclear Physics and Ion-beam Application(MOE) Institute of Modern PhysicsFudan UniversityShanghai 200433China Shanghai Research Center for Theoretical Nuclear Physics NSFC and Fudan UniversityShanghai 200438China Physics department and Center for Particle Physics and Field Theory Fudan UniversityShanghai 200438China

Ultra-peripheral heavy-ion collisions(UPCs)offer unique opportunities to study processes under strong electromagnetic *** these collisions,highly charged fast-moving ions carry strong electromagnetic fields that can be effectively treated as photon *** exchange of photons can induce photonuclear and two-photon interactions and excite *** excitation of the ions results in Coulomb dissociation with the emission of photons,neutrons,and other ***,the electromagnetic fields generated by the ions can be sufficiently strong to enforce mutual interactions between the two colliding ***,the two colliding ions experience an electromagnetic force that pushes them in opposite directions,causing a back-to-back correlation in the emitted *** a Monte Carlo simulation,we qualitatively demonstrate that the above electromagnetic effect is large enough to be observed in UPCs,which would provide a clear means to study strong electromagnetic fields and their effects.

关键词： Electromagnetic fields Neutrons Ultra-peripheral relativistic heavy-ion collisions(UPC)

Predicted Critical State Based on Invariance of the Lyapunov Exponent in Dual Spaces

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Chinese Physics Letters 2024年第1期41卷 68-76页

作者：刘通夏旭 department of applied Physics School of ScienceNanjing University of Posts and TelecommunicationsNanjing 210003China Academy of mathematics and System Sciences Chinese Academy of SciencesBeijing 100190China

Critical states in disordered systems,fascinating and subtle eigenstates,have attracted a lot of research ***,the nature of critical states is difficult to describe quantitatively,and in general,it cannot predict a system that hosts the critical *** propose an explicit criterion whereby the Lyapunov exponent of the critical state should be 0 simultaneously in dual spaces,namely the Lyapunov exponent remains invariant under the Fourier *** this criterion,we can exactly predict a one-dimensional quasiperiodic model which is not of self-duality,but hosts a large number of critical ***,we perform numerical verification of the theoretical prediction and display the self-similarity of the critical *** to computational complexity,calculations are not performed for higher dimensional ***,since the description of extended and localized states by the Lyapunov exponent is universal and dimensionless,utilizing the Lyapunov exponent of dual spaces to describe critical states should also be ***,we conjecture that some kind of connection exists between the invariance of the Lyapunov exponent and conformal invariance,which can promote the research of critical phenomena.

关键词： state exponent critical

Extreme parameter sensitivity of transient persistence in spatially coupled ecological systems

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Theoretical & applied Mechanics Letters 2011年第6期1卷 51-56页

作者： Lin Du, Wei xu,) and Zhanguo Li department of applied mathematics, Northwestern Polytechnical university, Xi’an 710072, china department of applied mathematics Northwestern Polytechnical University Xi'an 710072 China

This paper investigates persistence of transient dynamics depending on parameters in spatially coupled ecological systems. We emphasis that the persistence time can be obtained by populations of species or Lyapunov exponents of transient dynamics. It is found that extreme sensitive dependence of persistence on parameters occurs commonly in ecological models. A non-zero uncertainty exponent is used to characterize the high sensitivity in a reasonable parameter region. The result of a small uncertainty exponent indicates a fractal structure of transient persistence in the two-dimensional parameter space. In spite of different methods of measurement, the fractal dimensions have a good consistency. Since populations of natural communities with many coupled oscillators are often affected by disturbance of migration rates, the large probability of error in estimating persistence of transients should be concerned.

关键词： transient dynamics predator-prey systems persistence sensitivity uncertainty exponents fractal dimensions

Preliminary results in Local Discontinuous Galerkin Methods for Two Classes of 2D Nonlinear Wave Equations

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Preliminary results in Local Discontinuous Galerkin Methods ...