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Minimal systems of generators for central division algebra and semi-simple algebra

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Chinese Science Bulletin 1998年第21期43卷 1777-1780页

作者： QIU Qizhang 1.and SUN Ling 2.1. Department of Mathematics, Wuhan {1., Wuhan 430072. china 2. Department of Information science, Wuhan {1., Wuhan 430072. china. Department of Mathematics Wuhan University Wuhan China Department of Information science Wuhan University Wuhan China

Suppose that F is a field of characteristic zero and (ⅰ) D is a finite-dimensional central division algabra over F; (ⅱ) A is a finite-dimensional semi-simple algabra over F. It is proved that as F-algebras, D and A ... 详细信息

关键词： central division algebra semi-simple algebra generator minimal system of generators.

I-V and C-V properties of TiO_2.thin film by pulsed-laser reactive deposition

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Chinese Science Bulletin 1998年第16期43卷 1344-1349页

作者： FU Zhengwen 1. ZHOU Mingfei 1. ZHANG Shengkun 2.CHEN Lianyao 2.and QIN Qizong 1.1. Laser Chemistry Institute, Fudan university, Shanghai 2.0433, china 2. Department of Physics, Fudan university, Shanghai 2.0433, china Laser Chemistry Institute Fudan University Shanghai China Department of Pnysics Fudan University Shanghai China

TiO-2.thin films have bee deposited on p-Si(1.1. substrates by pulsed-laser ablation of metallic Ti target in the O-3 ambient. The current-voltage and capacitance-voltage of the Al/TiO-2.Si capacitors are measured. The results show that the dielectric constant of thin film after being annealed at 700℃ is found to be 46, and the border trap density and the interface state density at the TiO-2.p-Si interface are 1.8×1. 1.0}cm -2.and 2.1. 1.0}eV -1.cm -2. respectively. The conduction mechanisms of as-deposited films are also discussed.

关键词： TiO-2 dielectric properties electrical properties pulsed-laser deposition.

Monte Carlo calculation method on low energy electronscattering in polybasic medium

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Chinese Science Bulletin 1998年第2期43卷 171-174页

作者： TAN Zhenyu 1.and HE Yancai 2.1. College of Electric Power, Shandong {1. of Technology, Jinan 2.0061. china 2. Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 2.0050, china College of Electric Power Shandong University of Technology Jinan China Shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai China

A novel Monte Carlo method of simulating low energy electron (LEE) scattering in polybasic medium is presented. The Mott cross section is adopted to describe the elastic scattering of LEE, and a mean cross section idea is proposed instead of usual determination of the scattering center. The Joy’’s modified Bethe equation is used to calculate energy loss of LEE. The scattering processes of LEE in bulk PMMA have been simulated. And the electron backscattering coefficients, the electron interaction range and energy dissipation distribution of LEE in bulk PMMA have been calculated and compared with those calculated by the method of determining scattering center.

关键词： low_energy electron scattering Monte Carlo method cross_section.

Nonlinear analysis on the coupling process of electromagnetic vibrator and earth

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Science china Earth Sciences 2005年第8期48卷 1175-1182页

作者： CHEN Zubin1.2. TENG Jiwen2. LIN Jun1. ZHANG Linhang1.& JIANG Zhongjin1.1. Institute of Intelligent Instrument & Measurement Control Technology, Jilin university, Changchun 1.002., china 2. Institute of {2. & Geophysics, Chinese Academy of Sciences, Beijing 1.002., china 1. Institute of Intelligent Instrument & Measurement Control Technology Jilin University 130026 Changchun China 2. Institute of {1. & Geophysics Chinese Academy of Sciences 100029 Beijing China

The linear model based on the hydraulic pressure vibrator has been no longer adaptable to the electromagnetic vibrator. In order to realize the effective transmission of the limited energy from the vibrator to the ground, it is important to study the coupling model of the electromagnetic vibrator and the earth. In this paper, a nonlinear restore term was introduced to the coupling model because of the existence of a large amount of harmonics in the vibrator baseplate. The nonlinear vibration analysis was applied to the model by the multiscale method. In the course of energy transmission from the vibrator to the ground, ultraharmonic resonance was used to explain the generation of harmonics. An improved scheme was advanced to select the cross correlation reference signal in the vibrator seismic exploration. Good application results were obtained in field experiments.

关键词： vibrator, coupling model, electromagnetic, nonlinear vibration.

Determination of tectonic background for sedimentary basin from sandstone geochemistry

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Chinese Science Bulletin 1998年第14期43卷 1191-1196页

作者： SHAO Lei 1. K. Stattegger 2.and LI Wenhou 3 1. Laboratory of Marine {1., Tongji university, Shanghai 2.0092.{2. 2. Geological and Paleontological Institute, university of Kiel, 2.1.8 Kiel, Germany 3. Department of {1., Northwest Unive Laboratory of Marine geology Tongji University Shanghai China Geological and Paleontological Institute University of Kiel Kiel Germany Department of geology Northwest University Xi’an China

The chemical composition of sedimentary rocks is mainly controlled by source rocks. Through examining chemical composition of terrigenous rocks, the tectonic evolution of a sedimentary basin can be modeled. The Turpan Basin belongs to a continental sedimentary basin and its source rocks are derived from the upper continental crust.

关键词： sedimentary rock geochemistry basin analysis Turpan Basin.

Metallogenic characteristics of epithermal gold deposits in china

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Chinese Science Bulletin 1999年第S2期44卷 136-138页

作者： FENG Jianzhong~1.and WANG Jingbin~2.1. Department of {1., Peking university, Beijing 1.0871.{2. 2. Beijing Institute of {1. For Mineral Resources, Beijing 1.001.0}{2. Department of geology Peking University Beijing 100871 China Beijing Institute of geology for Mineral Resources Beijing 100012 China

VOLCANIC-SUBVOLCANIC rocks are extensively distributed in china, in which a series of epithermal golddeposits related to volcanism have been discovered. 1.Metallogenic tectonic settings of epithermal gold deposits The epithermal gold deposits are mainly formed under the following tectonic settings: (i) ancient island arc collision, such as Xingxingxia island arc, Armantai island arc, Beishan island arc and Jueluotage island arc, etc. in periphery of Gunggar, Altai, Baishan, etc. in ancient Europe domain; (ii) extension area of continental margin of back arc, such as Fujian, Zhejiang, Jiangsu and Henlongjiang, *** circum-Pacific metallogenic domain; (iii) Mesozoic-Cenozoic island arc, such as the Tethys-Himalayametallogenic domain and Taiwan; (iV) intracontinental faulting depression or intraplate deep-seatedfaults, such as northern Hebei, Liaoning, Inner Mongolia at the north margin of the North china platformand periphery of Taicheng-Loujiang fault.

关键词： metallogenic characteristics gold deposits china.

Optimization of thermomechanical processes in Cu-Cr-Zr lead frame alloy using neural networks and genetic algorithms

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Science china(Technological Sciences) 2005年第5期48卷 510-520页

作者： SU Juanhua1.2. LIU Ping2. DONG Qiming2.& LI Hejun1.1. College of Materials Science and Engineering, Northwestern Polytechnical university, Xi’an 71.072. china 2. College of Materials Science and Engineering, Henan university of Science and Technology, Luoyang 471.03, china 1. College of Materials Science and Engineering Northwestern Polytechnical University 710072 Xi’an China 2. College of Materials Science and Engineering Henan University of Science and Technology 471003 Luoyang China

The thermomechanical treatment process is effective in enhancing the properties of the lead frame copper alloy. In this study, an optimal pattern of the thermomechanical processes for Cu-Cr-Zr was investegated using an intelligent control technique consisting of neural networks and genetic algorithms. The input parameters of the artificial neural network (ANN) are the reduction ratio of cold rolling, aging temperature and aging time. The outputs of the ANN model are the two most important properties of hardness and conductivity. Based on the successfully trained ANN model, genetic algorithms (GA) are used to optimize the input parameters of the model and select perfect combinations of thermomechanical processing parameters and properties. The good generalization performance and optimized results of the integrated model are achieved.

关键词： Cu-Cr-Zr alloy, thermomechanical processing optimization, artificial neural network, genetic algorithms.

New type of adaptive control for a class of distributed time-delay systems with adaptation regard to delay parameter

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Journal of Systems Engineering and Electronics 2010年第6期21卷 1054-1062页

作者： Lin Chai1. 2. Shumin Fei1. 2. Haiyan Jin1. 2. Ruimin Wang1. 2. and Yanhong Li1. 2.1. Key Laboratory of Measurement and Control of Complex Systems of Engineering, Southeast university, Nanjing 2.0096, P. R. china 2. School of Automation, Southeast university, Nanjing 2.0096, P. R. china Key Laboratory of Measurement and Control of Complex Systems of Engineering Southeast UniversityNanjing 210096P.R.China School of Automation Southeast UniversityNanjing 210096P.R.China

The problem on stabilization for the system with distributed delays is researched. The distributed time-delay under consideration is assumed to be a constant time-delay, but not known exactly. A design method is proposed for a memory proportional and integral （PI） feedback controller with adaptation to distributed time-delay. The feedback controller with memory simultaneously contains the current state and the past distributed information of the addressed systems. The design for adaptation law to distributed delay is very concise. The controller can be derived by solving a set of linear matrix inequalities （LMIs）. Two numerical examples are given to illustrate the effectiveness of the design method.

关键词： distributed delay linear matrix inequality (LMI) adaptive control time-delay systems memory PI feedback.

Theoretical study on thermal decomposition of azoisobutyronitrile in ground state

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Science china Chemistry 2004年第5期47卷 373-380页

作者： SUN Chengke1.2. ZHAO Hongmei1.& LI Zonghe1.1. Department of Chemistry, Beijing Normal {1., Beijing 1.0875, china 2. Department of Chemistry, Qujing Normal College, Qujing 655000, china 1. Department of Chemistry Beijing Normal University 100875 Beijing China 2. Department of Chemistry Qujing Normal College 655000 Qujing China

The thermal decomposition mechanisms of azoisobutyronitrile (AIBN) in the ground state have been investigated systematically. Based on the potential energy surfaces (PES) of various possible dissociation paths obtained using the semiempirical AM1.method with partial optimization, the density function theory B3LYP/6-31.G* method was employed to optimize the geometric parameters of the reactants, the intermediates, the products and the transition states, which were further confirmed by the vibrational analysis. The obtained results show that the re- action process of the two-bond (three-body) simultaneous cleavage Me2.CN)C─ N=N─ C(CN)Me2. 2.e2.CN)C?+N2.is much more favorable than the reaction process of the two one- bond asynchronous cleavage Me2.CN)CN=N─C(CN)Me2.? Me2.CN)CN=N?+ Me2.CN)C?? Me2.CN)C?+ N2. It was suggested that the electron shrinking effect of double bond (─N=N─) in AIBN and the stabilities of the Me2.CN)C?radical as well as N2.molecule are main factors of leading to the reaction proceeding in the former pathway. The calculation results were consistent with all the experimental facts.

关键词： azoisobutyronitrile, radicals, thermal decomposition, density function theory (DFT).