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Size distributions and magic number characteristics of cluster configurations formed during solidification processes of liquid metal Al

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Science China(Technological Sciences) 2006年第2期49卷 172-187页

作者： LIU Rangsu1. LIU Fengxiang1. DONG Kejun1. ZHENG Caixing1. LIU Hairong2. PENG Ping2.& LI Jiyong3.1. {1. of Physics, hunan University, changsha {3. China 2. {1. of Material Science and Engineering, hunan University, changsha {3. China 3. department of chemistry, hunan University, changsha {3. China 1. department of Physics Hunan University Changsha 410082 China 2. department of Material Science and Engineering Hunan University Changsha 410082 China 3. department of chemistry Hunan University Changsha 410082 China

A molecular dynamics simulation study has been performed for a large systemconsisting of 1.0000 liquid metal Al atoms to investigate the formation and magic numbercharacteristics of the cluster configurations formed during the rapid solidification processes. Thecluster-type index method (CTIM) has been adopted to describe various types of clusterconfigurations. The results indicate that the icosahedral clusters (1. 0 1. 0) and theircombinations play the most important role in the rnicrostructure transitions during solidificationprocesses; for the cluster configurations of different levels formed by various combinations withdiffering numbers of basic clusters, their size distributions possess obvious magic number sequencewhich is in turn as 1.0}1.0}, 1.(2.0}, 2.-2.(2.), 3.-3.(3.), 3.-40, 43.44, 48..., (those in bracket arethe corresponding value in liquid state); the magic numbers correspond to the peak value positionsof the cluster numbers for corresponding level formed with various combinations by 1. 2. 3. 4, 5, 6,7, ...basic clusters, respectively. This magic number sequence is in good agreement with theexperimental results obtained by Harris et al. At the same time, this simulation study also gives ascientific and reasonable explanation to these experimental results.

关键词： liquid metal, solidification processes, cluster configuration, magic numbers, computer simulation.

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A Series Piezoelectric Quartz Crystal Response Kinetics for *** Growth in the Presence of Cu(Ⅱ)

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Journal of Central South University 2000年第1期12卷 15-19页

作者： CHAI Li yuan 1.2.,WEI Wan zhi 2.YAO Shou zhuo 2.1. {2. of Metallurgical Science and Engineering, Central South University of Technology, {1. 41.083. China 2. College of chemistry and Chemical Engineering, {3. University, {1. 1. department of Metallurgical Science and Engineering Central South University of Technology 410083 Changsha China 2. College of chemistry and Chemical Engineering Hunan University 410082 Changsha China

The kinetics on the growth of *** in the presence of Cu(Ⅱ) was studied using of series piezoelectric quartz crystal (SPQC). Arsenic ion inhibits the growth of *** , which is consistent with the previous results by other measuring methods. This further demonstrates that the SPQC can monitor the chemical activity of *** growth. Cupric ion accelerates the growth of *** . The mechanism was discussed, i. e., copper promotes the protein enzyme of *** , rusticyanin, to form over the range of cupric ion concentration studied. The reaction order of cupric ion in accelerating the bacterial growth is 0.067. The growth of *** is dependent on temperature, the apparent reaction activation energy decreases from 2..56 kJ/mol to 1..3. kJ/mol because of the addition of 1. mg/L Cu(Ⅱ) to the bacterial growth solution of pH 2.0 at initial inoculum of 1.%.

关键词： series piezoelectric quartz crystal T.ferrooxidans growth kinetics sigmoid curve cupric ion

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Molecular dynamics simulation of thermal stability of nanocrystalline vanadium

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Science China(Technological Sciences) 2006年第4期49卷 400-407页

作者： WEI Mingzhi1. XIAO Shifang1. YUAN Xiaojian2.& HU Wangyu1.2.1. Material Science and Engineering College, hunan University, {1. 41.082. China 2. {3. of Applied Physics, hunan University, {1. 41.082. China Material Science Engineering College Hunan University Changsha 410082 China department of Applied Physics Hunan University Changsha 410082 China

The microstructure and thermal stability of nanocrystalline vanadium with an average grain size ranging from 2.86 to 7.50 nm are calculated by means of the analytic embedded-atom method and molecular dynamics. The grain boundary and nanocrystal- line grain atoms are differentiated by the common neighbor analysis method. The results indicate that the fraction of grain boundary increases with the grain size decreasing, and the mean energy of atoms is higher than that of coarse crystals. The thermal-stable tem- peratures of nanocrystalline vanadium are determined from the evolution of atomic energy, fraction of grain boundary and radial distribution function. It is shown that the stable tem- perature decreases obviously with the grain size decreasing. In addition the reasons which cause the grain growth of nanocrystalline vanadium are discussed.

关键词： nanocrystalline, embedded-atom method, molecular dynamics, thermal stability.

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A new orthogonality relationship for orthotropic thin plate theory and its variational principle

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Science China(Physics,Mechanics & Astronomy) 2005年第3期48卷 371-380页

作者： LUO Jianhui 1., LONG Yuqiu 2.& LIU Guangdong 1.1. College of Civil Engineering, hunan University, {1. 41.082. China 2. {3. of Civil Engineering, Tsinghua University, Beijing 1.0084, China 1. College of Civil Engineering Hunan University 410082 Changsha China 2. department of Civil Engineering Tsinghua University 100084 Beijing China

The thought how dual vectors are constructed in a new orthogonality relationship for theory of elasticity is generalized into orthotropic thin plate bending problems by using the analogy theory between plane elasticity problems and plate bending problems. Dual differential equations are directly obtained by using a mixed variables method. A dual differential matrix to be derived possesses a peculiarity of which principal diagonal sub-matrixes are zero matrixes. Two independently and symmetrically orthogonality sub-relationships are discovered. By using the integral form for elastic bending theory of orthotropic thin plate the orthogonality relationship is demonstrated. By selecting felicitous dual vectors a new orthogonality relationship for theory of elasticity can be generalized into elastic bending theory of orthotropic thin plate. By using the integral form a variational principle which is relative to differential form and a whole function expression are proposed.

关键词： theory of elasticity, thin plate theory, dual vectors, orthogonality relationship, orthotropic, variational principle.

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Robust Fault Diagnosis of Analog Circuits with Tolerances

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湖南大学学报（自然科学版） 2000年第S2期27卷 133-138页

作者： Ying Deng1. Yigang He1., Xu He2.,Yichuang Sun{2.1. College of Electrical and Information Engineering,{1. University, 41.082. changsha, {1., China 2. department of Computer Science, {1. University, 41.082. changsha, {1., China {2. department of Ele

A method for robust analog fault diagnosis using hybrid neural networks is proposed. The primary focus of the paper is to provide robust diagnosis using a mechanism to deal with the problem of element tolerances and reduce testing time. The proposed approach is based on the fault dictionary diagnosis method and backward propagation neural network (BPNN) and the adaptive resonance theory (ART) neural network. Simulation results show that the method is robust and fast for fault diagnosis of analog circuits with tolerances.

关键词： Analog circuits Fault diagnosis Tolerances Artificial neural networ|

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Effect of static magnetic field on activity of immobilized α-amylase

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Chinese Science Bulletin 1997年第2期42卷 127-130页

作者： YAN Liushui, ZHU Yuanbao, HE-Shuang’e and CAO Zhixiang1.department of Chemical Engineering, Nanchang Institute of Aeronautical Technology, Nanchang {1.00{1., China 2. department of chemistry and Chemical Engineering, {{1. University, changsha 41.082. China department of Chemical Engineering Nanchang Institute of Aenwututical Techndogy Nanchang China department of {1. and Chemical Engineering Hunan University Changsha China

BIOLOGICAL effect of magnetic field is one of the three major subjects of contemporary biomagnetism, and is also the basis of applied biomagnetism. In order to explore magnetic biological effects, the influence of various sorts of magnetic field on many living systems as well as their different constructural levels has been extensively studied. However, only a few studies with in vitro enzyme have been reported, and few researches concerning the influence of magnetic field on immobilized enzyme reactions have been published. This note describes

关键词： static magnetic field immobilized α-amylase enzyme activity oscillatory behaviour.

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A low frequency piezoelectric power harvester using a spiral-shaped bimorph

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Science China(Physics,Mechanics & Astronomy) 2006年第6期49卷 649-659页

作者： HU Yuantai1.2.HU Hongping2.& YANG Jiashi3.1. Institute of Mechanics and Sensing Technology,Central South University,{1. 41.083.China 2. department of Mechanics,Huazhong University of Science and Technology,Wuhan 43.074,China 3. department of Engineering Mechanics,University of Nebraska,Lincoln,NE 68588-052.,USA 1. Institute of Mechanics and Sensing Technology Central South University Changsha 410083 China 2. department of Mechanics Huazhong University of Science and Technology Wuhan 430074 China 3. {1. of Engineering Mechanics University of Nebraska Lincoln NE 68588-0526 USA

We propose a spiral-shaped piezoelectric bimorph power harvester operating with coupled flexural and extensional vibration modes for applications to low frequency energy sources. A theoretical analysis is performed and the computational results show that the spiral structure has relatively low operating frequency compared to beam power harvesters of the same size. It is found that to optimize the performance of a piezoelectric spiral-shaped harvester careful design is needed.

关键词： spiral-shaped bimorph,piezoelectric harvester,power density.

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Resolution of α-cyclohexyl-mandelic acid enantiomers by two-phase (O/W) recognition chiral extraction

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Science China chemistry 2007年第6期50卷 764-769页

作者： TANG KeWen1.2. ZHANG GuoLi2. HUANG KeLong2. LI Yuanjian3.& YI JianMin1.2.1.{1. of chemistry and Chemical Engineering, hunan Institute of Science and Technology, Yueyang 41.000, China 2.College of chemistry and Chemical Engineering, Central South University, changsha 41.083. China 3.College of Pharmaceutical Science, Central South University, changsha 41.078, China department of {1. and Chemical Engineering Hunan Institute of Science and TechnologyYueyang 414000China College of chemistry and Chemical Engineering Central South UniversityChangsha 410083China

This paper presents a new chiral separation technology:two-phase(O/W)recognition chiral *** behavior of alpha-cyclohexyl-mandelic acid enantiomers was studied in the extraction system with D(L)-isobutyl tartrate in 1.2.dichloroethane organic phase and beta-CD derivatives in aqueous phase,and the influence of the kind and concentration of extractant and pH on extraction performance was *** experimental results indicate that two-phase(O/W)recognition chiral extraction is of strong chiral separation ***-^-CD,HE-beta-CD and Me-beta-CD have higher recognition ability for S-CHMA than that for R-CHMA,among which HP-beta-CD has the strongest ability;whereas,D-isobutyl tartrate has reversed recognition ability for *** the extraction system containing HP-beta-CD and D-isobutyl tartrate,e.e.% of S-CHMA in aqueous phase reached 2..6% by one stage extraction,and the distribution ratio for R-CHMA(k_R)and for S-CHMA(k_S)and separation factor(alpha)are 2.44,0.89 and 2.49,***,pH and concentration of extractant have great effects on chiral separation ***-phase(O/W)recognition chiral extraction has great significance for preparative separation of racemic compounds.

关键词： two-phase(W/0)recognition chiral extraction alpha-cyclohexyl-mandelic acid enantiomers

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Clinical and genetic analysis of two Chinese families with benign familial neonatal convulsions

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Progress in Natural Science:Materials International 2005年第8期15卷 757-760页

作者： LI Haiyan1. TANG Beisha1., XIA Kun2. CAO Guifang{2. SHEN Lu1. JIANG Hong1. PAN Qian2. SONG Yanmin1.and CAI Fang2.1. {1. of Neurology, Xiangya Hospital, Central South University, changsha 41.008, China 2. National Laboratory of Medical Genetics of China, changsha 41.008, China {2. {1. of Neurology, the First Affiliated Hospital, Tsinghua University, Beijing 1.0061. China) department of Neurology Xiangya Hospital Central South University Changsha 410008 China. National Laboratory of Medical Genetics of China Changsha 410008 China. department of Neurology First Affiliated Hospital Tsinghua University Beijing 100061 China

Benign familial neonatal convulsions (BFNC) is a rare autosomal dominant inherited epilepsy syndrome. Two voltage-gated potassium channel genes, KCNQ2.and KCNQ3. have been identified as the genes responsible for BFNC. Here we report two Chinese families with clinical histories of typical BFNC. Using six microsatellite markers, two located at KCNQ2.locus and four at KCNQ3.locus, linkage analysis was performed in the two families, which excluded the linkage of BFNC to KCNQ3. but could not exclude the linkage to KCNQ2. Direct DNA sequencing of the KCNQ2.gene in the two families was performed, and two formerly unknown polymorphisms were identified, but no KCNQ2.mutation was found in the two families. Our study suggests the genetic heterogeneity in Chinese families with BFNC and proves the existence of a new gene locus for BFNC.

关键词： BFNC epilepsy potassium channel linkage analysis mutation analysis.

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Nonlinear elastic waves in a monatomic chain with nonlinear interaction

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原子与分子物理学报 2002年第1期19卷 79-82页

作者： PAN Liu-xian 1. ZHOU Guang-hui 2. LI Shu-shen 3.1.{1. of Physics, Yiyang Teacher's College, Yiyang 41.0}49 2. {1. of Physics, hunan Normal University, {3. 41.081.3. National Laboratory for Supperlattice and Microstructure, Chinese department of Physics Yiyang Teacher's College Yiyang 413049 department of Physics Hunan Normal University Changsha 410081 中科院半导体所 National Laboratory for Supperlattice and Microstructure 北京 100083

Nonlinear wave equation for a one-dimensional anharmonic crystal lattice in terms of its microscopic parameters is obtained by means of a continuum approximation. Using a small time scale transformation, the nonlinear wave equation is reduced to a combined KdV equation and its single soliton solution yields the supersonic kink form of nonlinear elastic waves for the system.

关键词： Monatomic chain Continuum approximation Nonlinear elastic wave

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