检索结果-南通市图书馆

Finite-size effects in a D-dimensional ideal Fermi gas

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2009年第12期18卷 5189-5195页

作者：苏国珍欧聪杰 Wang A Qiu-Ping 陈金灿 Department of Physics and institute of Theoretical Physics and Astrophysics Xiamen University Xiamen 361005 China institut Supdrieur des Matdriaux et Mdcaniques A vancdes du mans 44 Av. Bartholdi 72000 Le Mans France

By using the Euler-MacLaurin formula, this paper studies the thermodynamic properties of an ideal Fermi gas confined in a D-dimensional rectangular container. The general expressions of the thermodynamic quantities with the finite-size corrections are given explicitly and the effects of the size and shape of the container on the properties of the system are discussed. It is shown that the corrections of the thermodynamic quantities due to the finite-size effects are significant to be considered for the case of strong degeneracy but negligible for the case of weak degeneracy or non-degeneracy. It is important to find that some familiar conclusions under the thermodynamic limit are no longer valid for the finite-size systems and there are some novel characteristics resulting from the finite-size effects, such as the nonextensivity of the system, the anisotropy of the pressure, and so on.

关键词： finite-size effect ideal Fermi gas thermodynamic property

Investigation of an energy nonadditivity for nonextensive systems

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2011年第34期56卷 3661-3665页

作者： WANG Ru NGANSO DJANTENG Sandrine KAABOUCHI EI Aziz WANG Qiuping Alexandre institut Supdieur des Materiaux du mans 44 Avenue F. A. Bartholdi Le Mans 72000 France College of Information Science and Engineering Huaqiao University Quanzhou 362021 China LPEC UMR CNRS 6087 Universite du Maine Av. O. Messiaen Le Mans 72085 France

We investigate the energy nonadditivity relationship E(AαB) = E(A) + E(B) + αE(A)E(B) which is often considered in the development of the statistical physics of nonextensive systems. It was recently found that α in this equation was not constant for a given system in a given situation and could not characterize nonextensivity for that system. In this work, we select several typical nonextensive systems and compute the behavior of α when a system changes its size or is divided into subsystems in different fashions. Three kinds of interactions are considered. It is found by a thought experiment that α depends on the system size and the interaction as expected and on the way we divide the system. However, one of the major results of this work is that, for given system, α has a minimum with respect to division position. Around this position, there is a zone in which α is more or less constant, a situation where the sizes of the subsystems are comparable. The width of this zone depends on the interaction and on the system size. We conclude that if α is considered approximately constant in this zone, the two mathematical difficulties raised in previous studies are solved, meaning that the nonadditive relationship can characterize the nonadditivity of the system as an approximation. In all the cases, α tends to zero in the thermodynamic limit (N→∞) as expected.

关键词：子系统能源统计物理学热力学极限相互作用思想实验近似系统等式

Application of varentropy as a measure of probabilistic uncertainty for complex networks

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2011年第34期56卷 3677-3682页

作者： JIANG Jian WANG Ru PEZERIL Michel WANG Qiuping Alexandre institut superieur des Materiaux et Mecaniques Avarices 44 Avenue F.A. Bartholdi 72000 Le Mans France Complexity Science Center Institute of Particle Physics Central China Normal University Wuhan 430079 China LPEC Faculte des Sciences et Techniques Universite du Maine Ave. O. Messiaen 72035 Le Mans France College of Information Science and Engineering Huaqiao University Quanzhou 362021 China

Varentropy is used as a general measure of probabilistic uncertainty for a complex network, inspired by the first and second laws of thermodynamics, but not limited to the equilibrium system. By exploring the relationship between the varentropy of the scale free distribution and the exponent of power laws as well as network size, we get the optimal design of a scale-free network against random failures. The behaviors of varentropy and the Shannon entropy of double Pareto law degree distribution are analyzed to compare their usefulness. Our conclusion is that varentropy is suitable and reliable.

关键词：概率不确定性网络应用 Shannon熵无标度网络第二定律平衡系统幂律指数网络规模

Large electromechanical strain at high temperatures of novel <001> textured BiFeGaO3-BaTiO3 based ceramics

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2020年第13期47卷 92-99页

作者： Jiangguli Peng Wenbin Liu Jiangtao Zeng Liaoying Zheng Guorong Li Anthony Rousseau Alain Gibaud Abdelhadi Kassiba Key Laboratory of Inorganic Functional Material and Device Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 201899China institut des Molécules et Matériaux du mans(IMMM) CNRS UMR 6283Facultédes SciencesUniversitédu MaineAvenue O.Messiaen72085 Le MansCedex 09France Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

BiFeGaO3-BaTiO3(BFG-BT)based ceramics with a large piezoelectric coefficient are potential high performance lead-free piezoelectric *** this work,textured and random BFG-BT ceramics were realized by the solid state reaction method with and without BaTiO3(BT)*** ceramics were obtained by a reactive templated grain growth(RTGG)method leading to a high-temperature electromechanical strain of S=0.27%at 40 kV/cm and to an effective piezoelectric coefficient(d33*)up to 685 pm/V at 180℃.The easy movement of oriented domains enhanced the electromechanical strain under an applied electric field in textured sample(Lotgering factor f=66.3%).Structural investigations reveal that the proportion and degree of distortion of BFG-BT rhombohedral phase(R3c)reached its maximum in textured ceramics,resulting in large ferrodistortive displacements under electric *** addition,the dense nanodomains with low domain wall energies,inferred from the high-resolution transmission electron microscope(HR-TEM)observations,contribute to the extra displacement of the textured sample under an applied electric *** textured ceramics,the remnant polarization was stable(about 17μC/cm2)from room temperature to 180℃,contributing to the stable ferroelectric property at high *** the introduction of BT templates,high-density nanodomains were formed and the Burns temperature was enhanced in textured *** electromechanical strain,polarization and dielectric behavior were correlated to the textured or random forms of the BFG-BT based ceramics.

关键词： Textured ceramics Strain hysteresis Reactive templated grain growth Dielectric responses

Comparative study using MS and XRD of Fe_(80)Al_(20) alloy produced by mechanical alloying

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2013年第8期56卷 1504-1507页

作者： HADEF F. OTMANI A. GRENèCHE J.M. Laboratoire de Recherche sur la Physico-Chimie des Surfaces et Interfaces LRPCSIUniversité 20 Ao t 1955BP 26Route d'El-HaddaiekSkikda 21000Algérie LUNAM Université du MaineInstitut des Molécules et Matériaux du MansIMMM UMR CNRS 628372085 Le MansFrance

An X-ray diffraction and 57Fe MOssbauer effect study of mechanically alloyed Fe80Al20 is presented. X-ray measurements indicate that the disordered bcc α-Fe（A1） solid solution was formed after 2 h of milling, while the analysis of Mrssbauer spectra suggested that total dissolution of aluminium is achieved after 10 h of milling. These differences can be attributed to：（i） rapid nanocrystallization of aluminium and/or （ii） small particles with small amounts of aluminium cannot be detected by the X-ray diffraction technique.

关键词： nanostructured materials Fe-AI alloys mechanical alloying X-ray diffraction M6ssbauer spectrometry

The uncertainty measure for q-exponential distribution function

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2013年第13期58卷 1524-1528页

作者： OU CongJie EL KAABOUCHI Aziz WANG QiuPing Alexandre CHEN JinCan College of Information Science and Engineering Huaqiao University institut Supérieur des Matériaux et Mécaniques Avancés du mans 44Avenue F.A. Bartholdi72000 Le MansFrance Department of Physics Xiamen University

Based on the q-exponential distribution which has been observed in more and more physical systems, the uncertainty measure of such an abnormal distribution can be derived by employing a variational relationship which can be traced from the first and second thermodynamic laws. The uncertainty measure obtained here can be considered as the entropic form for the abnormal physical systems having observable q-exponential distribution. This entropy will tend to the Boltzmann-Gibbs entropy when the nonextensive parameter tends to unity. It is very important to find that this entropic form is always concave and the systemic entropy is maximizable.

关键词：不确定性度量分布函数不确定性测度指数分布物理系统异常分布热力学定律吉布斯

Power law and small world properties in a comparison of traffic city networks

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2011年第34期56卷 3731-3735页

作者： MA Ke WANG ZhongWen JIANG Jian ZHU GuangXi LI Wei Department of Physics College of Maths and Physics China University ofGeosciences Wuhan 430074 China Department of Electronics and Information Engineering Huazhong University of Science and Technology Wuhan 430074 China Department of Mathematics Kashgar Teachers College Kashgar 844006 China institut superieur des Materiaux du mans 44 Avenue F.A. Bartholdi 72000 Le Mans France institute of Particle Physics Central China Normal University Wuhan 430079 China

We analyze the statistical properties of the urban public bus networks of two cities (Beijing and Chengdu) in China. To this end, we present a comprehensive survey of the degree distribution, average path length, and clustering of both networks. It is shown that both networks exhibit small world behavior and are hierarchically organized. We also discuss the differences between the statistical properties displayed by the two networks. In addition, we propose a weight distribution approach to study the passenger flow through the public bus networks we considered. A hierarchical structure is observed here also.

关键词：城市网络小世界属性交通统计特性公交网络路径长度重量分配

^(57)Fe Mössbauer spectrometry: A powerful technique to analyze the magnetic and phase characteristics in RE–Fe–B permanent magnets

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2021年第1期30卷 73-86页

作者： Lizhong Zhao Xuefeng Zhang Mi Yan Zhongwu Liu Jean-Marc Greneche institute of Advanced Magnetic Materials College of Materials&Environmental EngineeringHangzhou Dianzi UniversityHangzhou 310018China State Key Laboratory of Silicon Materials School of Materials Science and EngineeringKey Laboratory of Novel Materials for Information Technology of Zhejiang ProvinceZhejiang UniversityHangzhou 310027China School of Materials Science and Engineering South China University of TechnologyGuangzhou 510640China institut des Mol´ecules et Mat´eriaux du mans CNRS UMR-6283 Le Mans Universit´eLe Mans F-72085France

This review summarizes the recent advances on the application of ^(57)Fe Mössbauer spectrometry to study the magnetic and phase characteristics of Nd–Fe–B-based permanent magnets. First of all, the hyperfine structures of the Ce_(2)Fe_(14)B,(Ce,Nd)_(2)Fe_(14)B and MM_(2)Fe_(14)B phases are well-defined by using the model based on the Wigner-Seitz analysis of the crystal structure. The results show that the isomer shift δ and the quadrupole splitting öEQ of those 2:14:1 phases show minor changes with the Nd content, while the hyperfine field Bhfincreases monotonically with increasing Nd content and its value is influenced by the element segregation and phase separation in the 2:14:1 phase. Then, the hyperfine structures of the low fraction secondary phases are determined by the ^(57)Fe Mössbauer spectrometry due to its high sensitivity. On this basis,the content, magnetic behavior, and magnetization of the REFe_(2) phase, the amorphous grain boundary(GB) phase, and the amorphous worm-like phase, as well as their effects on the magnetic properties, are systematically studied.

关键词： ^(57)Fe Mössbauer spectrometry Nd–Fe–B-based permanent magnets (Ce,Nd)_(2)Fe_(14)B phase grain boundary phase

Long Division Unites or Long Union Divides:a Model for Social Network Evolution

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2013年第3期30卷 206-210页

作者： JIANG Jian WANG Ru Pezeril Michel Wang Qiuping Alexandre Complexity Science Center and institute of Particle Physics Huazhong Normal UniversityWuhan 430079 institut Supérieur des Matériaux et Mécaniques Avancés 44 Avenue F.A.Bartholdi72000 Le MansFrance IMMM UMR 6283Universitédu MaineAve.O.Messaen72085 Le MansFrance College of Mathematics and Computer Science of Wuhan Textile University Wuhan 430200 College of Infromation Science and Engineering Huajiao UniversityQuanzhou 362021

A remarkable phenomenon in the time evolution of many networks such as cultural,political,national and economic systems is the recurrent transition between the states of union and the division of *** propose a phenomenological modeling,inspired by the maxim"long union divides and long division unites"to investigate the evolutionary characters of these networks composed of the entities whose behaviors are dominated by these two *** nodes are endowed with quantities such as identity,ingredient,richness(power),openness(connections),age,distance,and interaction,which determine collectively the evolution in a probabilistic *** on a tunable parameter,the time evolution of this model is mainly an alternative domination of union or division state,with a possible state of final union dominated by one single node.

关键词： union collective quantities