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Maps on Positive Cones of C^(*)-algebras

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Acta Mathematica Sinica,English Series 2023年第3期39卷 387-398页

作者： ming chu GAO Gui Mei AN Department of Mathematics Louisiana Christian UniversityPinevilleLA 71359USA School of Mathematical Sciences and LPMC Nankai UniversityTianjin 300071P.R.China

We prove that a surjective map(on the positive cones of unital C^(*)-algebras)preserves the minimum spectrum values of harmonic means if and only if it has a Jordan *-isomorphism extension to the whole *** represent weighted geometric mean preserving bijective maps on the positive cones of prime C^(*)-algebras in terms of Jordan *-isomorphisms of the *** also characterize order isomorphisms and orthoisomorphisms of the projection lattice of the von Neumann algebra of all bounded linear operators on a Hilbert space,answering an open question arisen by ***,we give a description for Fuglede-Kadison determinant preserving maps on the positive cone of a finite von Neumann algebra and improve Gaal and Nayak’s work on this topic.

关键词： Operator means preserving maps positive cones projection lattices Fuglede-Kadison Determinants

Influence of static pre-loading on the dynamic bending strength of concrete with particle element modeling

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Science China(Technological Sciences) 2015年第2期58卷 284-296页

作者： WU ming Xin ZHANG chu Han State Key Laboratory of Hydroscience and Engineering Tsinghua University

Experimental tests show that static pre-loading has a significant effect on the dynamic strength of *** on meso-scale particle element model,numerical simulations of dynamic bending tests with pre-loading are *** stress–strain relationships are then *** increase in dynamic strength is found when the pre-loadings are imposed within the elastic limit of ***,when the imposition of pre-loadings reaches the plastic or softening range,dynamic strengths may gradually decrease along with the increase in *** distribution of energy components and the failure modes are discussed to explain the mechanisms of the phenomena.

关键词： concrete static pre-loading dynamic bending strength rate effect particle element modeling

Towards understanding abscisic acid-mediated leaf senescence

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Science China(Life Sciences) 2015年第5期58卷 506-508页

作者： liang Chengzhen chu Chengcai State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing) Institute of Genetics and Developmental Biology Chinese Academy of Sciences

Senescence is a necessary part of most complex organisms that controlled by many complicated genetic programs. However, unlike animals and humans, leaf senescence has a great impact on nutrient recycling from source to sink to promote reproductive success, thus has strong adaptive advantages in plants. Therefore, from the agricultural point of view, understanding the process of leaf senescence is extremely important for the breeding of higher-yielding crop with optimized nutritional qualities.

关键词：叶片衰老脱落酸介导植物适应性组成部分遗传程序养分循环品质育种

Pion and Kaon Production in Heavy-Ion Reactions at 1GeV/Nucleon

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Chinese Physics Letters 1996年第10期13卷 730-733页

作者： ZHENG Yu-ming chu Zi-li China Institute of Atomic Energy Beijing 102413

The pion and kaon production in heavy-ion reactions at 1GeV/nucleon has been investigated in the relativistic Vlasor-Uehling-Uhlenbeck model, which has been generalized to include the effect of nuclear medium on kaon and pion. The calculated results show that the attractive pion optical potential not only enhances apparently the yield of pions with low transverse momenta, leading to a reasonable fit to the experimental data, but also increases the kaon abundance.

关键词： attractive transverse ion.

Sharp power-type Heronian and Lehmer means inequalities for the complete elliptic integrals

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Applied Mathematics(A Journal of Chinese Universities) 2023年第3期38卷 467-474页

作者： ZHAO Tie-hong chu Yu-ming School of Mathematics Hangzhou Normal UniversityHangzhou 311121China Department of Mathematics Huzhou UniversityHuzhou 313000China

In the article,we prove that the inequalities H_(p)(K(r);E(r))>π/2;L_(q)(K(r);E(r))>π/2 hold for all r 2(0;1)if and only if p≥3=4 and q≥3=4,where Hp(a;b)and Lq(a;b)are respectively the p-th power-type Heronian mean and q-th Lehmer mean of a and b,and K(r)and E(r)are respectively the complete elliptic integrals of the first and second kinds.

关键词： power-type Heronian mean Lehmer means complete elliptic integrals

Superfluorescence from halide perovskite nanocrystal superlattices

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Journal of Semiconductors 2022年第10期43卷 5-6页

作者： liang chu Lixiu Zhang Liming Ding School of Electronics and Information Hangzhou Dianzi UniversityHangzhou 310018China Center for Excellence in Nanoscience(CAS) Key Laboratory of Nanosystem and Hierarchical Fabrication(CAS)National Center for Nanoscience and TechnologyBeijing 100190China

Progress has been made in accurately manipulating the size and shape of monodisperse nanocrystals over past 30 *** 1993,Bawendi et *** monodisperse CdS,CdSe and CdTe nanocrystals with similar size by a hot-injec-tion method[1].After two years,they prepared CdSe nanocrys-tal superlattices by self-assembling method with two distinct morphologies:faceted colloidal crystals and ordered thin *** size and spacing of nanocrystals were controlled with a nearly atomic precision[2].Then,engineering morpho-logy,interaction and surrounding environment are encour-aged to construct superlattices at atomic ***,the advanced technologies like electron microscopy and X-ray related tools help scientists to deeply understand the struc-tures and properties of nanocrystal superlattices[3].Com-pared to individual nanocrystal,their superlattices indicate col-lective properties due to coupling between nanocrystals[4].For instance,their original properties are enhanced because the ordered nanocrystals interact with each other under the light,electric or magnetic field;new properties can be gener-ated by the periodically ordered structures of the assembly;and comprehensive properties can be obtained via assem-bling nanocrystals with different functions.

关键词： ordered disperse size

Effective Response of Nonlinear Composite under External AC and DC Electric Field

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Communications in Theoretical Physics 2005年第4X期44卷 731-734页

作者： LIU Ye liang Fang-chu SHEN Hong-liang Institute of Oceanology the Chinese Academy of Sciences Qingdao 266071 China Graduate School of the Chinese Academy of Sciences Beijing 100039 China Department of Mathematics Ningbo University of Technology Ningbo 315016 China Hebei Province Tobacco Quality Testing Station of Hebei Tobacco Company Shijiazhuang 050051 China

A perturbation method is used to study effective response of nonlinear Kerr composites, which are subject to the constitutive relation of electric displacement and electric field, Dα=εαE＋xα｜E｜^2E. Under the external AG and DC electric field Eapp = Eα（1 ＋ sinωt）, the effective nonlinear responses and local potentials are induced by the cubic nonlinearity of Kerr materials at all harmonics. As an example in three dimensions, we have investigated this kind of nonlinear composites with spherical inclusions embedded in a host. At all harmonic frequencies, the potentials in inclusion and host regions are derived. Furthermore, the formulae of the effective linear and nonlinear responses are given in the dilute Iimit.

关键词： nonlinear composite dielectric response AC electric field

Predicted interfacial thermal conductance and thermal conductivity of diamond/Al composites with various interfacial coatings

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Rare Metals 2011年第5期30卷 544-549页

作者： liang Xuebing JIA Chengchang chu Ke CHEN Hui School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China General Research Institute for Nonferrous Metals （GRINM） Beijing 100083 China

The interfacial thermal conductance （ITC） and thermal conductivity （TC） of diamond/Al composites with various coatings were theoretically studied and discussed. A series of predictions and numerical analyses were performed to investigate the effect of thickness, sound velocity, and other parameters of coating layers on the ITC and TC. It is found that both the ITC and TC decline with increasing coating thickness, especially for the coatings with relatively low thermal conductivity. Nevertheless, if the coating thickness is close to zero, or quite a small value, the ITC and TC are mainly determined by the constants of the coating material. Under this condition, coatings such as Ni, TiC, Mo 2 C, SiC, and Si can significantly improve the ITC and TC of diamond/Al composites. By contrast, coatings like Ag will exert the negative effect. Taking the optimization of interfacial bonding into account, conductive carbides such as TiC or Mo 2 C with low thickness can be the most suitable coatings for diamond/Al composites.

关键词： metallic matrix composites coatings diamonds thermal conductivity interfacial thermal conductance

Effects of Joint Controller on Analytical Modal Analysis of Rotational Flexible Manipulator

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Chinese Journal of Mechanical Engineering 2015年第3期28卷 460-469页

作者： chu ming ZHANG Yanheng CHEN Gang SUN Hanxu Automation School Beijing University of Posts and Telecommunications

Modal analysis is a fundamental and important task for modeling and control of the flexible manipulator. However, almost all of the traditional modal analysis methods view the flexible manipulator as a pure mechanical structure and neglect feedback action of joint controller. In order to study the effects of joint controller on the modal analysis of rotational flexible manipulator, a closed-loop analytical modal analysis method is proposed. Firstly, two exact boundary constraints, namely servo feedback constraint and bending moment constraint, are derived to solve the vibration partial differential equation. It is found that the stiffness and damping gains of joint controller are both included in the boundary conditions, which lead to an unconventional secular term. Secondly, analytical algorithm based on Ritz approach is developed by using Laplace transform and complex modal approach to obtain the natural frequencies and mode shapes. And then, the numerical simulations are performed and the computational results show that joint controller has pronounced influence on the modal parameters： joint controller stiffness reduces the natural frequency, while joint controller damping makes the shape phase non-zero. Furthermore, the validity of the presented conclusion is confirmed through experimental studies. These findings are expected to improve the performance of dynamics simulation systems and model-based controllers.

关键词： flexible manipulator analytical modal analysis boundary constraints joint controller