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Entropy product measure for multipartite pure states

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Science China(physics,Mechanics & Astronomy) 2006年第5期49卷 606-615页

作者： CAO Wancang1,2, LIU Dan2, PAN Feng3.& LONG Guilu2,4 1. department of physics, Chifeng College, Chifeng 024001, China 2. Key Laboratory for Quantum Information and Measurements, department of physics, Tsinghua university, Beijing 100084, China 3. department of physics, Liaoning normal university, Dalian 116029, China 4. Key Laboratory for Atomic and Molecular Nano-Sciences, Tsinghua university, Beijing 100084, China Correspondence should be addressed to Long Guilu department of physics Chifeng College Chifeng 024001 China Key Laboratory for Quantum Information Measurements Department of Physics Tsinghua University Beijing 100084 China department of physics Liaoning Normal University Dalian 116029 China Key Laboratory for Atomic Molecular Nano-Sciences Tsinghua University Beijing 100084 China

An entanglement measure for multipartite pure states is formulated using the product of the von Neumann entropy of the reduced density matrices of the constituents. Based on this new measure, all possible ways of the maximal entanglement of the triqubit pure states are studied in detail and all types of the maximal entanglement have been compared with the result of ‘the average entropy’. The new measure can be used to calculate the degree of entanglement, and an improvement is given in the area near the zero entropy.

关键词： multipartite pure state von Neumann entropy entanglement measure

Silicon nanoporous pillar array and its surface copper deposition

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Chinese Science Bulletin 2005年第14期50卷 1424-1428页

作者： FU Xiaonan1,2,3. CHAI Huadou1,2 & LI Xinjian1,2 1. department of physics, Zhengzhou university, Zhengzhou 450052, China 2. Key Laboratory of Material physics (Zhengzhou university), Ministry of Education, Zhengzhou 450052, China 3. department of Mathematics and physics, Henan university of Tech- nology, Zhengzhou 450052, China department of physics Zhengzhou University Zhengzhou 450052 China Key Laboratory of Material physics (Zhengzhou university) Ministry of Education Zhengzhou 450052 China department of Mathematics and physics Henan University of Technology Zhengzhou 450052 China

Silicon nanoporous pillar array (Si-NPA) has been prepared by a hydrothermal etching technique. Using Si-NPA as substrate, a Cu/Si-NPA nanocomposite thin film has been obtained with immersion plating method. Morpho- logical and structural analysis indicates that Si-NPA is a typical structural composite system characterized by a triple hierarchical structure, i. e. the array of micron-sized silicon pillars, the nanopores densely distributed on the surface of the pillars, and the silicon nanocrystallites that constitute the pore walls. Cu/Si-NPA inherits the morphological character- istics of Si-NPA. The compactability of the deposited copper nanoparticles varies alternatively with the local geometrical features of Si-NPA and forms a quasi-periodical pattern. Such an experimental phenomenon is attributed to the veloc- ity dependence of the copper deposition upon the local geo- metrical features of Si-NPA. These results indicate that Si-NPA might be used as an ideal template for preparing specially patterned, structured or functionalized metal/ sili- con nanocomposite systems.

关键词：硅元素薄膜蚀刻技术电镀技术

Analysis on cohesive crack opening displacement considering the strain softening effect

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Science China(physics,Mechanics & Astronomy) 2006年第1期49卷 88-101页

作者： WANG Limin1, XU Shilang2 & ZHAO Xiqiang3.1. Mechanics department, Shandong university of Technology, Zibo 255049, China 2. Civil Engineering department, Dalian university of Technology, Dalian 116024, China 3. Mathematics department, Ocean university of China, Qingdao 266071, China Mechanics department Shandong University of Technology Zibo 255049 China Civil Engineering department Dalian University of Technology Dalian 116024 China Mathematics department Ocean University of China Qingdao 266071 China

In order to investigate the crack propagation in quasi-brittle materials like rock, ceramic and concrete, Hillerborg and his co-researchers abstracted the fracture process zone in front of a stress free crack in terms of a “fictitious crack zone”. On the fictitious crack zone, cohesive stresses distribute following a given softening relationship of stress vs. crack opening. Based on the polynomial or power series expression of cohesive crack opening displacement, the relationship of the cohesive stress vs. the crack opening displacement is established using elastic theory and integral equation, and some unknown physics variables are obtained using variation approach. The calculation results gained in this paper are close to the experimentally test ones.

关键词： cohesive crack, softening, dissipation work, variation approach.

X-ray spectra induced by ^(129)Xe^(q+) impacting the metal surface

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Science China(physics,Mechanics & Astronomy) 2008年第1期51卷 82-89页

作者： ZHANG XiaoAn 1,2 ,XIAO GuoQing 1 ,YANG ZhiHu 1 ,CHEN XiMeng 3.,ZHAO YongTao 1 , LI FuLi 4 ,WANG Li 1,2 ,CUI Ying 3.,ZHANG HongQiang 3.&ZHAN WenLong 1 1Institute of Modern physics,Chinese Academy of Sciences,Lanzhou 73.000,China 2department of physics,Xianyang{3. university,Xianyang 712000,China 3.1} of Modern physics,Lanzhou university,Lanzhou 73.000,China 4department of Applied physics,Xi’an Jiaotong university,Xi’an 710049,China 1. Institute of Modern physics Chinese Academy of Sciences Lanzhou 730000 China 2. department of physics Xianyang Normal University Xianyang 712000 China 3. department of Modern physics Lanzhou University Lanzhou 730000 China 4. department of Applied physics Xi’an Jiaotong University Xi’an 710049 China

Using the slow highly charged ions 129 Xe q+ (q=25,26,27;initial kinetic T0≤4.65 keV/a.u.)to impact Au surface,the Au atomic Mαcharacteristic X-ray spectrum is *** result shows that as long as the charge state of projectile is high enough,the heavy atomic characteristic X-ray can be effectively excited even though the incident beam is very weak(nA magnitude),and the X-ray yield per ion is in the order of 10-8and increases with the kinetic energy and potential energy of *** measuring the Au Mα-X-ray spectra,Au atomic N-level lifetime is estimated at about 1.3.×10-18s based on Heisenberg uncertainty relation.

关键词： slow highly charged ions characteristic X-ray level lifetime

SU（m+n）SU（m）×SU（n） ISOSCALAR FACTORS AND S（f1+f2）S（f1）×S（f2） OUTER-PRODUCT ISOSCALAR FACTORS

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Acta Mathematica Scientia 1985年第1期5卷 19-34页

作者：陈金全 department of physics Nanjing University Nanjing China

It is proved that the SU（m+n）SU（m）×SU（n） isoscalar factors （ISF） are equal to the S（f1+f2） outer-product ISF of the permutation group. Since the latter only depend on the partition labels, the values of the SU（m+n）SU（m）×SU（n） ISF do not depend on m and n explicitely. Consequently for a f（=f1+f2）-particle system, by evaluating the S（f） S（f1）×S（f2） outer-product ISF we can obtain all （an infinite number） of the SU （m+n） SU（m）×SU（n） ISF （or the f2-particle coefficients of fractional parentage） for arbitrary m and n at a single stroke, in stead of one m and one n at a time. A simple method, the eigenfunction method, is given for evaluating the SU（m+n） SU（m）×SU（n） single particle ISF, while the many-particle ISF can be calculated in terms of the outer-product reduction coefficients and the transformation coefficients from the Yamanouchi basis to the S（f1+f2） S（f1）×S（f2） basis.

关键词： ISF SU m+n f1+f2 f2

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Science China Mathematics 2004年第5期47卷 659-674页

作者： SHI Peihu & WANG Mingxindepartment of Mathematics, Southeast university, nanjing 210018, China department of Mathematics, Xuzhou normal university, Xuzhou 221116, China 1. department of Mathematics Southeast University 210018 Nanjing China 2. department of Mathematics Xuzhou Normal University 221116 Xuzhou China

This paper is devoted to study the classification of self-similar solutions to the quasilinear parabolic equations with nonlinear gradient termsu t = Δ(u m) - uq∣Δu∣ p withm ≥ 1,p,q > 0 andp +q >m. Form = 1, it is shown that the very singular self-similar solution exists if and only ifnq + (n +1)p 1, it is shown that very singular self-similar solutions exist if and only if 1

关键词： quasilinear parabolic equations, self-similar solutions, very singular solution, classification.

Sonochemical effect of a bifrequency irradiation

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Chinese Science Bulletin 2000年第2期45卷 142-145页

作者： ZHU Changping, FENG Ruo & ZHAO Yiyun department of physics. Jingzhou normal College, Jingzhou 43.100, China State Key Laboratory of Modern Acoustics,{3. university,{3. 210093. China Chemistry department of Yunnan university, Kunming 650091, Ch department of physics Jingzhou Normal College Jingzhou China State Key Laboratory of Modern Acoustics Nanjing University Nanjing China Chemistry department of Yunnan university Kunming China

The sonochemical effect of a bifrequency orthogonal ultrasonic irradiation has been studied by using two different detecting methods. It has been shown that the sonochemical yield produced by the bifrequency irradiation appears to be much more than the sum of the yields produced separately by the two irradiations. The bifrequency irradiation, therefore, can be expected to exert a great influence on the development of sonohemical

关键词： bifrequency sonochemistry effect.

Diffuse interstellar absorption bands

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Science China(physics,Mechanics & Astronomy) 2009年第4期52卷 489-501页

作者： XIANG FuYuan1,2,LIANG ShunLin2 & LI AiGen2,3.1 Faculty of Materials,Photoelectronics and physics,Xiangtan university,Xiangtan 411105,China 2 department of physics and Astronomy,university of Missouri,Columbia,MO 65211,USA 3.Purple Mountain Observatory,Chinese Academy of Sciences,nanjing 210008,China 1. Faculty of Materials Photoelectronics and Physics Xiangtan University Xiangtan 411105 China 2. department of physics and Astronomy University of Missouri Columbia MO 65211 USA 3. Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 China

The diffuse interstellar bands(DIBs) are a large number of absorption bands that are superposed on the interstellar extinction curve and are of interstellar origin. Since the discovery of the first two DIBs in the 1920s,the exact nature of DIBs still remains unclear. This article reviews the history of the detections of DIBs in the Milky Way and external galaxies,the major observational characteristics of DIBs,the correlations or anti-correlations among DIBs or between DIBs and other interstellar features(e.g. the prominent 2175 Angstrom extinction bump and the far-ultraviolet extinction rise),and the proposed candidate carriers. Whether they are also present in circumstellar environments is also discussed.

关键词： astrophysics interstellar matter interstellar extinction diffuse interstellar band circumstellar environment

Robustness and breakup of the spiral wave in a two-dimensional lattice network of neurons

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Science China(physics,Mechanics & Astronomy) 2010年第4期53卷 672-679页

作者： MA Jun 1,2, TANG Jun 2 , ZHANG AiHua 3.& JIA Ya 2 1 department of physics, Lanzhou university of Technology, Lanzhou 73.050, China 2 department of physics, Central China normal university, Wuhan 43.079, China 3.College of Electrical and Information Engineering, Lanzhou university of Technology, Lanzhou 73.050, China 1. department of physics Lanzhou University of Technology Lanzhou 730050 China2. Department of Physics Central China Normal University Wuhan 430079 China3. College of Electrical and Information Engineering Lanzhou University of Technology Lanzhou 730050 China

The robustness and breakup of spiral wave in a two-dimensional lattice networks of neurons are investigated. The effect of small- world type connection is often simplified with local regular connection and the long-range connection with certain probability. The network effect on the development of spiral wave can be better described by local regular connection and changeable long-range connection probability than fixed long-range connection probability because the long-range probability could be changeable in realistic biological system. The effect from the changeable probability for long-range connection is simplified by multiplicative noise. At first, a stable rotating spiral wave is developed by using appropriate initial values, parameters and no-flux boundary conditions, and then the effect of networks is investigated. Extensive numerical studies show that spiral wave keeps its alive and robust when the intensity of multiplicative noise is below a certain threshold, otherwise, the breakup of spiral wave occurs. A statistical factor of synchronization in two-dimensional array is defined to study the phase transition of spiral wave by checking the membrane potentials of all neurons corresponding to the critical parameters(the intensity of noise or forcing current)in the curve for factor of synchronization. The Hindmarsh-Rose model is investigated, the Hodgkin-Huxley neuron model in the presence of the channel noise is also studied to check the model independence of our conclusions. And it is found that breakup of spiral wave is easier to be induced by the multiplicative noise in presence of channel noise.

关键词： spiral wave factor of synchronization breakup multiplicative noise robustness