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Exploration and progress of high-energy supercapacitors and related electrode materials

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Science China(Technological Sciences) 2015年第11期58卷 1851-1863页

作者： yang mei XIA Hui School of Materials Science and Engineering Nanjing University of Science and Technology Herbert Gleiter Institute of Nanoscience Nanjing University of Science and Technology

As one of new electrical energy storage systems, supercapacitors possess higher energy density than conventional capacitors and larger power density than batteries, integrating substantial merits with high energy, large power delivery, long cycle life, obvious safety, and low cost. However, the unsatisfying energy density is the inhabiting issue for the wide commercial applications. As the energy density(E, W h kg?1) is directly proportional to specific capacitance(C, F g?1) and the square of operating voltage(V, V), in this review, we summarize the recent progress in two sections: the exploration of high-performance electrode materials to achieve high specific capacitance and the construction of high-voltage supercapacitor systems for high working voltage. The progressive explorations and developments in supercapacitors could guide the future research towards high-performance, low-cost, and safe energy storage devices.

关键词： electrochemical capacitors high-energy supercapacitors electrode materials energy density energy storage systems

The Products of Three Theta Functions and the General Cubic Theta Functions

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Acta Mathematica Sinica,English Series 2010年第6期26卷 1115-1124页

作者： Xiao mei yang Department of Mathematics East China Normal University Shanghai 200241 P. R. China

In this paper we establish two theta function identities with four parameters by the theory of theta functions. Using these identities we introduce common generalizations of Hirschhorn-Garvan-Borwein cubic theta functions, and also re-derive the quintuple product identity, one of Ramanujan＇s identities, Winquist＇s identity and many other interesting identities.

关键词： Jacobi theta function quintuple product identity Winquist's identity Ramanujan identity

SimET: An open-source tool for estimating crop evapotranspiration and soil water balance for plants with multiple growth cycles

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The Crop Journal 2023年第5期11卷 1579-1585页

作者： Minguo Liu mei yang Huimin yang State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems College of Pastoral Agriculture Science and TechnologyLanzhou UniversityLanzhou 730020GansuChina

Accurate estimation of crop evapotranspiration(ETc) and soil water balance, which is vital for optimizing water management strategy in crop production, can be performed by simulation. But existing software has many deficiencies, including complex operation, limited scalability, lack of batch processing, and a single ETc model. Here we present simET, an open-source software package written in the R programming language. Many concepts involved in crop ETc simulation are condensed into functions in the package. It includes three widely used crop ETc models built on these functions: the single-crop coefficient,double-crop coefficient, and Shuttleworth–Wallace models, along with tools for preparing model data and comparing estimates. SimET supports ETc simulation in crops with repeated growth cycles such as alfalfa, a perennial forage crop that is cut multiple times annually.

关键词： Crop evapotranspiration Soil water balance Evapotranspiration model R package

Effects of the properties of Mg(OH)_(2)precursor on the hydrothermal synthesis of magnesium oxysulfate whiskers

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Particuology 2024年第9期92卷 13-23页

作者： Thanayos Boonrit mei yang Guangwen Chen Dalian Institute of Chemical Physics Chinese Academy of SciencesDalian116023China University of Chinese Academy of Sciences Beijing100049China

Magnesium oxysulfate(MOS)whiskers are commonly synthesized through a dissolution-precipitation mechanism,wherein Mg(OH)_(2)dissolves to form Mg(OH)_(6)^(4−),followed by reactions with SO_(4)^(2−)and H_(2)O to yield MOS ***,the impact of Mg(OH)_(2)precursor properties on the formation process of MOS whiskers has been insufficiently explored,and sector-like and needle-like morphologies were both observed in previous *** this study,we systematically investigated how the properties of Mg(OH)_(2)precursors influenced the crystalline structure and morphology of MOS *** various experimental conditions,MgSO_(4)·5Mg(OH)_(2)·2H_(2)O(152MOS)whiskers were consistently obtained,regardless of Mg(OH)_(2)morphology and *** size of Mg(OH)_(2)emerged as a critical factor in shaping the morphology of 152MOS ***-sized Mg(OH)_(2)(≤106±37 nm)favored the formation of sector-like whiskers,while larger-sized Mg(OH)_(2)(≥206±98 nm)encouraged the development of needle-like *** distinction was attributed to the slower dissolution rate exhibited by larger-sized Mg(OH)_(2),maintaining a smaller number of 152MOS nuclei and promoting the growth of needle-like whiskers instead of the aggregation of 152MOS nuclei into sector-like *** addition,the effects of the molar ratio of Mg^(2+)to SO_(4)^(2−)and hydrothermal temperature were also *** average length and diameter of the needle-like whiskers prepared with Mg(OH)_(2)of 331±145 nm under optimized conditions were 77±32 and 0.39±0.10μm,*** study presented an effective strategy for controlling the morphology of 152MOS whiskers.

关键词： Magnesium oxysulfate whiskers Morphology control Precursor Microreactor

HEAVY BALL FLEXIBLE GMRES METHOD FOR NONSYMMETRIC LINEAR SYSTEMS

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Journal of Computational Mathematics 2022年第5期40卷 711-727页

作者： mei yang Ren-Cang Li School of Mathematical Sciences Shanghai Jiao Tong UniversityShanghai 200240China Department of Mathematics University of Texas at ArlingtonArlingtonTXUSA

Flexible GMRES(FGMRES)is a variant of preconditioned GMRES,which changes preconditioners at every Arnoldi *** often has to be restarted in order to save storage and reduce orthogonalization cost in the Arnoldi *** restarted GMRES,FGMRES may also have to be restarted for the same reason.A major disadvantage of restarting is the loss of convergence *** this paper,we present a heavy ball flexible GMRES method,aiming to recoup some of the loss in convergence speed in the restarted flexible GMRES while keep the benefit of limiting memory usage and controlling orthogonalization *** tests often demonstrate superior performance of the proposed heavy ball FGMRES to the restarted FGMRES.

关键词： GMRES Flexible GMRES Heavy ball GMRES Preconditioner Linear system.

ADAPTIVE CGF COMMANDER BEHAVIOR MODELING THROUGH HTN GUIDED MONTE CARLO TREE SEARCH

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Journal of Systems Science and Systems Engineering 2018年第2期27卷 231-249页

作者： Xiao Xu mei yang Ge Li College of System Engineering National University of Defense Technology Changsha 410073 China

Improving the intelligence of virtual entities is an important issue in Computer Generated Forces （CGFs） construction. Some traditional approaches try to achieve this by specifying how entities should react to predefined conditions, which is not suitable for complex and dynamic environments. This paper aims to apply Monte Carlo Tree Search （MCTS） for the behavior modeling of CGF commander. By look-ahead reasoning, the model generates adaptive decisions to direct the whole troops to fight. Our main work is to formulate the tree model through the state and action abstraction, and extend its expansion process to handle simultaneous and durative moves. We also employ Hierarchical Task Network （HTN） planning to guide the search, thus enhancing the search efficiency. The final implementation is tested in an infantry combat simulation where a company commander needs to control three platoons to assault and clear enemies within defined areas. Comparative results from a series of experiments demonstrate that the HTN guided MCTS commander can outperform other commanders following fixed strategies.

关键词： Monte Carlo Tree Search Hierarchical Task Network Computer generated force Behaviormodeling

Progress and Perspectives of Hollow Multishelled Structures

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Chinese Journal of Chemistry 2022年第10期40卷 1190-1203页

作者： Jiangyan Wang mei yang Dan Wang State Key Laboratory of Biochemical Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Hollow multishelled structure(HoMs)has drawn tremendous attention due to its abundant attractive properties and promising ***,for a long time,the limited synthesis method hindered the development of *** sequential templating approach developed by our group,has greatly enriched its composition and'structure *** progress in HoMS synthesis promotes the discovery of its characteristics as well as widens its application ***,the recently explored temporal-spatial ordering characteristic of HoMS has shown great promise in drug delivery and cascade catalysis application ***,we summarize the current development progress of HoMS in the aspects of both synthesis and application,with a focus discussion on how to shape its application performance by manipulating its composition and structure *** addition,we discuss the current challenges and providethe future potentials holdingfor HoMs.

关键词： Hollow multishelled structure Sequential templating approach Temporal-spatial ordering Catalysis Structure-activity relationships

The first complete mitogenome of Acharax sp.(Protobranchia,Solemyida,Solemyidae):comparisons with other Solemyidae bivalves and deep-sea adaptive characteristics

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Journal of Oceanology and Limnology 2023年第6期41卷 2374-2390页

作者： mei yang Jixing SUI Xinzheng LI Department of Marine Organism Taxonomy&Phylogeny Institute of OceanologyChinese Academy of SciencesQingdao 266071China Center for Ocean Mega-Science Chinese Academy of SciencesQingdao 266071China University of Chinese Academy of Sciences Beijing 100049China Laboratory for Marine Biology and Biotechnology Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237China

Solemyidae is an ancient group of protobranch bivalves,and most solemyids are symbiotic with chemoautotrophic and gill-hosted bacteria,enabling them to survive in unusual habitats such as deepsea chemosynthetic ***,evolution of the mitogenomes in this family and their phylogenetic relationships remain poorly *** complete mitogenome of Acharax *** determined and compared with other available mitogenomes of *** mitogenome of Acharax *** 18970 bp in length and consists of 13 protein-coding genes,2 ribosomal RNA genes,and 22 transfer RNA *** gene arrangement was identical to those of other sequenced *** the present five mitogenomes of Solemyidae species,all protein-coding genes were initiated with the typical ATD(ATA,ATG,and ATT)codon and terminated with the TAA/TAG ***,the incomplete termination codon was *** Ka/Ks ratio analyses indicated that 13 protein-coding genes of five Solemyidae mitogenomes suffered strong purifying *** to 45 existing shallow water equivalents,the 18 available mitogenomes from the deep-sea,including the Acharax *** this study,show significantly more nonpolar amino acids in the 13 protein-coding genes,which indicates the adaptation to the deep-sea *** phylogenetic tree based on 48 Bivalvia complete mitogenomes provided further information to support the scientific classification of *** relationships among Solemyidae were assessed based on 2 mitochondrial(16S rRNA and COX1)and 3 nuclear(18S rRNA,28S rRNA,and histone H3)gene sequences from 17 in-group *** two genera Acharax and Solemya formed a monophyletic clade each,and Acharax *** with previously reported Acharax bivalves with high support values.

关键词： Solemyidae Acharax mitogenome deep sea adaptation phylogeny

Rheological Behavior of the Melts for Polyethylene-based Montmorillonite Nanocomposites

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Chemical Research in Chinese Universities 2006年第5期22卷 651-657页

作者： yang Hong-mei ZHENG Qiang DU Miao Department of Polymer Science and Engineering Zhejiang University Hangzhou 310027 P. R. China National Engineering Research Center for Compounding and Modification of Polymer Materials Guiyang 550025 P. R. China

The viscoelastic properties of melts of nanocomposites with partially exfoliated structures, which were composed of low-density polyethylene （LDPE）, ethylene vinyl acetate copolymer （EVA）, and montmofillonite and modified by cetyltrimethyl ammonium bromide and octadecyltrimethyl ammonium bromide, were studied. The results obtained through measurements of the dynamic storage modulus G′, the dynamic loss modulus G″, and the transiem stress relaxation modulus G（t） of the composites, reveal that the viscoelastic properties of the composites strongly depend on the amount of montmorillonite that is exfoliated into the composites. With the increase in montmoriUonite content, the composites show an obvious property of pseudo solid-like materials within the region of lower frequencies （ω）. The montmorillonite layers are aligned along the stress direction, and the dependence of dynamic modulus on ω, appears quite different for the composites before and after being exposed to a large amplitude oscillatory shears.

关键词： Rheological behavior Nanocomposite Polyethylene Montmorillonite