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Compound Product of Hypermatrices

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Journal of Systems Science & Complexity 2024年第1期37卷 169-183页

作者： CHENG Daizhan MENG min ZHANG Xiao ji Zhengping Key Laboratory of Systems and Control Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China Department of Control Science and Engineering School of Electronics and Information EngineeringTongji UniversityShanghai 201210China National Center for Mathematics and Interdisciplinary Sciences Chinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100149China.

The semi-tensor product(STP)of matrices is generalized to multidimensional arrays,called the compound product of *** product is first defined for three-dimensional hypermatrices with compatible orders and then extended to general *** different types of hyperdeterminants are introduced and certain properties are *** Lie groups and Lie algebras corresponding to the hypermatrix products are ***,these results are applied to dynamical systems.

关键词： Compound semi-tensor product hyperdeterminants hypereigenvalues and hypereigenvectors hypergeneral linear groups hypermatrices.

Impact of photoneutrons on reactivity measurements for TMSR-SF1

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Nuclear Science and Techniques 2017年第6期28卷 101-107页

作者： Rui-min ji ming-Hai Li Yang Zou Gui-min Liu Shanghai Institute of Applied Physics Chinese Academy of Sciences University of Chinese Academy of Sciences

The solid-fueled thorium molten salt reactor(TMSR-SF1) is a 10 MW_(th) test reactor design to be deployed in 5-10 years by the TMSR *** design combines coated particle fuel and molten FLiBe coolant for great intrinsic safety features and economic *** to a large amount of beryllium in the coolant salt,photoneutrons are produced by(y,n) reaction,hence the increasing fraction of effective delayed neutrons in the core by the photoneutrons originating from the long-lived fission *** of the delayed photoneutron groups are of long lifetime,so a direct effect is resulted in the transient process and reactivity *** study the impact of photoneutrons for TMSR-SF1,the effective photoneutron fraction is estimated using k-ratio method and performed by the Monte Carlo code(MCNP5) with ENDF/B-Ⅶ cross *** on the coupled neutronphoton point kinetics equations,influence of the photoneutrons is *** results show that the impact of photoneutrons is not negligible in reactivity *** considering photoneutrons in on-line reactivity measurement based on inverse point kinetics can result in overestimation of the positive reactivity and underestimation of the negative *** photoneutrons also lead to more waiting time for the doubling time *** the photoneutron precursors take extremely long time to achieve equilibrium,a "steady" power operation may not directly imply a "real" criticality.

关键词： TMSR-SF1 Delayed photoneutrons Coupled neutron-photon point kinetics Reactivity measurement

Wall-Attached Night Ventilation Combined with Phase Change Material Wallboard in Hot Summer:An Experimental Study on the Thermal Performance

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Journal of Thermal Science 2022年第2期31卷 318-331页

作者： ji Wenhui YUAN Yanping LI Yajun YU min School of Mechanical Engineering Southwest Jiaotong UniversityChengdu 610031China

Night ventilation is regarded as a promising cooling strategy by storing night cooling in the thermal mass of the ***,night ventilation performance in hot summer is restricted by the climatic *** this paper,we propose a new solution as the integration of wall-attached night ventilation(WANV)and phase change material wallboard(PCMW).The principle of the proposed system is to utilize the wall-attached jet ventilation to achieve forced convection and to adopt latent energy storage of PCMW to enlarge the energy storage density capabilities,and the coupling method is expected to improve the night ventilation *** experiments were conducted to evaluate the thermal performance of the hybrid system by evaluating indoor temperature history,thermal comfort time and cooling *** to the high thermal energy storage density capability of PCMW,it was found that the presence of PCMW has a negative influence on night cooling efficiency but still has a positive influence on the overall cooling *** proposed WANV combined with the PCMW system significantly increased the temperature decrease of room air and west wall inside surface during one hour's night ventilation by 94.97%and 67.74%,respectively,and reached an extension of 38.42%of indoor thermal comfort *** results highlight the potential of WANV integration of PCMW to improve the thermal performance of night ventilation.

关键词： night ventilation wall-attached jet ventilation phase change material wallboard thermal performance

A Modified Formulation of Singular Boundary Method for Exterior Acoustics

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Computer Modeling in Engineering & Sciences 2023年第4期135卷 377-393页

作者： Yi Wu Zhuojia fu jian min Institute of Grid and High Performance Computing College of Mechanics and MaterialsHohai UniversityNanjing211100China

This paper proposes amodified formulation of the singular boundarymethod(SBM)by introducing the combined Helmholtz integral equation formulation(CHIEF)and the self-regularization technique to exterior *** the SBM,the concept of the origin intensity factor(OIF)is introduced to avoid the singularities of the fundamental *** SBM belongs to the meshless boundary collocation *** additional use of the CHIEF scheme and the self-regularization technique in the SBM guarantees the unique solution of the exterior acoustics accurately and ***,by using the SBM coupled with the CHIEF scheme and the self-regularization technique,the accuracy of the numerical solution can be improved,especially near the corresponding internal characteristic *** numerical examples of two-dimensional and threedimensional benchmark examples about exterior acoustics are used to verify the effectiveness and accuracy of the proposed *** proposed numerical results are compared with the analytical solutions and the solutions obtained by the other numerical methods.

关键词： Singular boundary method CHIEF method self-regularization technique acoustic radiation and scattering

Monothetic and conductive network and mechanical stress releasing layer on micron-silicon anode enabling high-energy solid-state battery

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Rare Metals 2024年第3期43卷 1017-1029页

作者： Xiang Han min Xu Lan-Hui Gu Chao-Fei Lan min-Feng Chen Jun-jie Lu Bi-fu Sheng Peng Wang Song-Yan Chen ji-Zhang Chen College of Materials Science and Engineering Co-Innovation Center of Efficient Processing and Utilization of Forestry ResourcesNanjing Forestry UniversityNanjing210037China Department of Physics Xiamen UniversityXiamen361005China Western Digital Corporation MilpitasCA95035USA

Silicon has ultrahigh capacity,dendrite-free alloy lithiation mechanism and low cost and has been regarded as a promising anode candidate for solid-state *** to the low infiltration of solid-state electrolyte(SSE),not the unstable solid-electrolyte interphase(SEI),but the huge stress during lithiation-and delithiation-induced particle fracture and conductivity lost tend to be the main *** this study,starting with micron-Si,a novel monothetic carbon conductive framework and a MgO coating layer are designed,which serve as electron pathway across the whole electrode and stress releasing layer,*** addition,the in situ reaction between Si and SSE helps to form a LiF-rich and mechanically stable SEI *** a result,the mechanical stability and charge transfer kinetics of the uniquely designed Si anode are significantly ***,high initial Coulombic efficiency,high capacity and durable cycling stability can be achieved by applying the Si@MgO@C anode in *** example,high specific capacity of 3224.6 mAh·g^(-1)and long cycling durability of 200 cycles are *** work provides a new concept for designing alloy-type anode that combines surface coating on particle and electrode structure design.

关键词： Lithium-ion battery(LIB) Solid-state electrolyte(SSE) Silicon anode Stress relief Coating

Algebraic Method for Constructing Exact Discrete Soliton Solutions of Toda and mKdV Lattices

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Communications in Theoretical Physics 2008年第6期49卷 1407-1409页

作者： WANG Jun-min ji jie School of Information Henan University of Finance and Economics Zhengzhou 450002 China College of Statistics and Mathematics Zhejiang Gongshang University Hangzhou 310018 China

In this paper, with the aid of symbolic computation, we present a new method for constructing soliton solutions to nonlinear differentiM-difference equations. And we successfully solve Toda and mKdV lattice.

关键词： soliton solutions differential-difference equation

Analysis of Seismic Response for Vugular Reservoir Physical Model Data

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石油地球物理勘探 2009年第A2期44卷 79-85页

作者： ji min National Lab of Oil Resource and Survey China University of Petroleum (Beijing) Beijing 102249 China. Key Lab of Geophysical Prospecting China University of Petroleum (Beijing) Beijing 102249 China

Powder metallurgy of high-entropy alloys and related composites: A short review

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International Journal of minerals,Metallurgy and Materials 2021年第6期28卷 931-943页

作者： Bo-ren Ke Yu-chen Sun Yong Zhang Wen-rui Wang Wei-min Wang Pei-yan Ma Wei ji Zheng-yi fu State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China Beijing Advanced Innovation Center of Materials Genome Engineering State Key Laboratory for Advanced Metals and MaterialsUniversity of Science and Technology BeijingBeijing 100083China School of Mechanical Engineering University of Science and Technology BeijingBeijing 100083China School of Physics and Astronomy Shanghai Jiao Tong UniversityShanghai 200240China School of Chemistry Chemical Engineering and Life ScienceWuhan University of TechnologyWuhan 430070China

High-entropy alloys(HEAs)have attracted increasing attention because of their unique properties,including high strength,hardness,chemical stability,and good wear *** metallurgy is one of the most important methods used to fabricate HEA *** paper introduces the methods used to synthesize HEA powders and consolidate HEA *** phase transformation,microstructural evolution,and mechanical properties of HEAs obtained by powder metallurgy are *** also address HEA-related materials such as ceramic–HEA cermets and HEA-based composites fabricated by powder metallurgy.

关键词： high-entropy alloys powder metallurgy mechanical alloying consolidation

On the complexity of ω-pushdown automata

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Science China(Information Sciences) 2017年第11期60卷 156-170页

作者： Yusi LEI fu SONG Wanwei LIU min ZHANG Shanghai Key Laboratory of Trustworthy Computing East China Normal University School of Information Science and Technology Shanghai Tech University School of Computer Science National University of Defense Technology

Finite automata over infinite words(called ω-automata) play an important role in the automatatheoretic approach to system verification. Different types of ω-automata differ in their succinctness and complexity of their emptiness problems, as a result, theory of ω-automata has received considerable research *** automata over infinite words(called ω-PDAs), a generalization of ω-automata, are a natural model of recursive programs. Our goal in this paper is to conduct a relatively complete investigation on the complexity of the emptiness problems for variants of ω-PDAs. For this purpose, we consider ω-PDAs of five standard acceptance types: B¨uchi, Parity, Rabin, Streett and Muller acceptances. Based on the transformation for ω-automata and the efficient algorithm proposed by Esparza et al. in CAV’00 for verifying the emptiness problem of ω-PDAs with B¨uchi acceptance, it is trivial to check the emptiness problem of other ω-PDAs. However, this naive approach is not optimal. In this paper, we propose novel algorithms for the emptiness problem of ω-PDAs based on the observations of the structure of accepting runs. Our algorithms outperform algorithms that go through B¨uchi PDAs. In particular, the space complexity of the algorithm for Streett acceptance that goes through B¨uchi acceptance is exponential, while ours is polynomial. The algorithm for Parity acceptance that goes through B¨uchi acceptance is in O(k3n2m) time and O(k2nm) space, while ours is in O(kn2m) time and O(nm) space, where n(resp. m and k) is the number of control states(resp. transitions and index). Finally,we show that our algorithms yield a better solution for the pushdown model checking problem against linear temporal logic with fairness.

关键词： pushdown automata emptiness ω-words model checking linear temporal logic