检索结果-南通市图书馆

DISTURBANCE REJECTION AND TRACKINGDESIGN VIATHE SSR APPROACH FOR SECOND ORDERUNCERTAIN SYSTEMS

在线全文

学校读者我要写书评

暂无评论

Systems Science and Mathematical sciences 1999年第S1期12卷 96-103页

作者： HUANG Yi HAN Jingqing(institute of Systems Science, chinese academy of sciences, Beijing {2., china)

In this paper, the SSR approach and some nonlinear approaches are used fordisturbance rejection design and object tracking design. The theoretical analysis and thesimulation results show that the abilities of strong disturbance rejection and small trackingerror can be obtained by nonlinear design approaches and that the response speed and thespecification of no overshoot can be designed separately by the SSR approach.

关键词： Uncertain systems the SSR approach nonlinear design approach disturbance rejection tracking problem.

Research on Thermal Effect of Window of High Power Fast Axial Flow CO2.Laser

在线全文

学校读者我要写书评

暂无评论

chinese Journal of Lasers 2000年第2期9卷 116-120页

作者： JIANG Jinbo CHENG Zhaogu NIU Zhenya ( Shanghai institute of Optics and fine Mechanices, The chinese academy of sciences, Shanghai 2.1800, {2. Chagnchun institute of Optics and fine Mechanics, chinese academy of sciences, The Changchun 13002., {2.) 中科院上海光学精密机械所上海中科院长春光学精密机械所吉林长春

Because of the thermal effect of window of high power fast axial flow CO2.aser, the coupler will be distorted and become a convex lens. In this paper, the thermal distorted coupler is taken as a quasi-lens ABCD system, and through experiment and theoretical analysis, relations between the position of the output beam waist, the beam waist size, divergence angle, and the output power are given.

关键词： quasi-lens ABCD system beam waist

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

小批量生产过程中产品质量控制的研究

系统工程理论与实践 2002年第5期22卷 24-30页

作者：张文生中国科学院软件研究所

借助支持向量机技术解决了下面三个问题 :1 .在给定核函数的前提下 ,客观地、系统地给出一组增强输入模式 ,进而构造指出向量机网络 ,求出小批量数据所遵循的规律 ;2..通过理论分析说明 ,该方法不仅能控制学习结果对测试样本的误差 ,而... 详细信息

借助支持向量机技术解决了下面三个问题 :1 .在给定核函数的前提下 ,客观地、系统地给出一组增强输入模式 ,进而构造指出向量机网络 ,求出小批量数据所遵循的规律 ;2..通过理论分析说明 ,该方法不仅能控制学习结果对测试样本的误差 ,而且能提高学习结果的泛化能力 ,从而避免 BP学习过程的缺陷 ,;3.通过求解小批量生产过程产品质量规律的实例 ,验证了上述结果。

关键词：小批量生产过程产品质量控制函数型连接网络支持向量机现代制造业

Conformational Studies of Arabinoglucuronomannology (AGM)

在线全文

学校读者我要写书评

暂无评论

生物物理学报 1996年第4期12卷 547-553页

作者： Imshik Lee Bai Chunli Wang Chen (institute of Chemistry, chinese academy of sciences, Beijing, {2.) 中科院化学所北京

ＣｏｎｆｏｒｍａｔｉｏｎａｌＳｔｕｄｉｅｓｏｆＡｒａｂｉｎｏｇｌｕｃｕｒｏｎｏｍａｎｎｏｌｏｇｙ（ＡＧＭ）ＩｍｓｈｉｋＬｅｅ；ＢａｉＣｈｕｎｌｉ；ＷａｎｇＣｈｅｎ（ＩｎｓｔｉｔｕｔｅｏｆＣｈｅｍｉｓｔｒｙ，Ｃｈｉｎｅ... 详细信息

ＣｏｎｆｏｒｍａｔｉｏｎａｌＳｔｕｄｉｅｓｏｆＡｒａｂｉｎｏｇｌｕｃｕｒｏｎｏｍａｎｎｏｌｏｇｙ（ＡＧＭ）ＩｍｓｈｉｋＬｅｅ；ＢａｉＣｈｕｎｌｉ；ＷａｎｇＣｈｅｎ（ＩｎｓｔｉｔｕｔｅｏｆＣｈｅｍｉｓｔｒｙ，ＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＳｃｉｅｎｃ...

关键词： Arabinoglucuronomannology(AGM) X - ray diffraction Conformation Relative humidity (RH)

Mechanisms of the pancake vortex and vortex line movement in the high T_c superconductors Bi_2.r_2.aCu_2._8+δ and La_(1.93)Sr0.0_7CuO_4+δ

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(physics,Mechanics & Astronomy) 2007年第2期50卷 240-248页

作者： WANG WeiXian1,ZHOU Fang2.TAN Shun1,WU Huan1 & ZHANG YuHeng1 1 National High Magnetic Field Laboratory,University of Science and Technology of china,Hefei 2.002.,china 2.National Laboratory for Superconductivity,lnstitute of {2. and the Center for Condensed Matter {2.,chinese academy of sciences,Beijing 100080,china 1. National High Magnetic Field Laboratory University of Science and Technology of China Hefei 230026 China 2. National Laboratory for Superconductivity Institute of Physics and the Center for Condensed Matter Physics Chinese Academy of Sciences Beijing 100080 China

In the strict sense, it is not very clear why with magnetic field increasing, the normal-superconductive (NS) transition becomes broad for Bi2.r2.aCu2.8+δ(Bi2.12. while the NS transitions are almost parallel for La193Sroo7Cu04+δ(La2.4). In this paper, R-T relations are measured by the six-probe method. We propose a moving mechanism of the pancake vortex and vortex line for Bi2.12. The theoretical curves fit the experiment data well.

关键词： superconductivity superconductive pancake vortex dynamics

Accurate studies on dissociation energies of diatomic molecules

在线全文

学校读者我要写书评

暂无评论

Science china(physics,Mechanics & Astronomy) 2007年第5期50卷 611-621页

作者： SUN WeiGuo1, FAN QunChao1 & REN WeiYi1,2.1 institute of physics, Sichuan University, Chengdu 610065, {2. 2.institute of theoretical physics, Xihua Normal University, Nanchong 637002. {2. institute of physics Sichuan University Chengdu 610065 China institute of theoretical {2. Xihua Normal University Nanchong 637002 China

The molecular dissociation energies of some electronic states of hydride and N2.molecules were studied using a parameter-free analytical formula suggested in this study and the algebraic method (AM) proposed recently. The results show that the accurate AM dissociation energies DeAM agree excellently with experimental dissociation energies Deexpt, and that the dissociation energy of an electronic state such as the 2.Δg state of 7Li2.whose experimental value is not available can be predicted using the new formula.

关键词： algebraic method, diatomic molecule, vibrational energy, dissociation energy

Experimental studies on perturbed acoustic resonant spectroscopy by a small rock sample in a cylindrical cavity

在线全文

学校读者我要写书评

暂无评论

Science china(physics,Mechanics & Astronomy) 2006年第6期49卷 683-701页

作者： CHEN Dehua1,2.WANG Xiuming2.3,CONG Jiansheng1,XU Delong1,SONG Yanjie1 & MA Shuilong4 1. Department of Geophysics,Daqing Petroleum institute,Daqing 163318,{2. 2. institute of Acoustics,chinese academy of sciences,Beijing 100080,{2. 3. Division of Petroleum,Australian Commonwealth Scientific and Industrial Research Organization,Bent-ley WA 6102.Australia 4. Daqing Testing and Technology Services Corporation,Daqing 163153,{2. Department of Geophysics Daqing Petroleum Institute Daqing 163318 China institute of Acoustics Chinese Academy of Sciences Beijing 100080 China Division of Petroleum Australian Commonwealth Scientific Industrial Research Organization Bentley WA 6102 Australia Daqing Testing Technology Services Corporation Daqing 163153 China

A measurement system for acoustic resonant spectroscopy (ARS) is estab-lished,and the effects of resonant cavity geometry,inner perturbation samples and envi-ronmental temperature on the ARS are investigated. The ARSs of the small samples with various sizes and acoustic properties are measured. The results show that at the normal pressure,the resonant frequency decreases gradually with the increase of liquid tem-perature in the cylindrical cavity,while the resonant amplitude increases. At certain pres-sure and temperature,both the resonant frequency and the amplitude decrease greatly when there exist air bubbles inside the cavity fluid. The ARS is apparently affected by the sample porosity and the sample location in the resonant cavity. At the middle of the cavity,the resonant frequencies reach their maximum values for all of the measurement samples. The resonant frequencies of the porous rock samples are smaller than those of the com-pacted samples if other acoustic parameters are the same. As the sample is moved from the top to the middle of the cavity along its axis,the resonant amplitude increases gradu-ally for the compacted rocks while decreases for the unconsolidated rocks. Furthermore,the resonant amplitude increases firstly and then decreases if the porosity of the rock sample is relatively small. In addition,through the comparisons between the experimental and theoretical results,it is found that the effects of the acoustic parameters and sizes of the samples and the size of the cylindrical cavity on the laboratory results agree well with the theoretical ones qualitatively. These results may provide basic reference for the ex-periment study of rock acoustic properties in a low frequency using ARS.

关键词： acoustic resonant spectroscopy,acoustic velocity and attenuation,experiment measurement,rock acoustic property.

DFT study of the conductance of molecular wire:The effect of coupling geometry and intermolecular interaction on the transport properties

在线全文

学校读者我要写书评

暂无评论

Science china Chemistry 2006年第6期49卷 492-498页

作者： QI Yuanhua1,2. GUAN Daren1 & LIU Chengbu1 1. institute of theoretical Chemistry, Shandong University, Jinan 2.0100, {2. 2. School of physics and Microelectronics, Shandong University, Jinan 2.0061, {2. 1. institute of theoretical Chemistry Shandong University Jinan 250100 China 2. School of physics and Microelectronics Shandong University Jinan 250061 China

The density functional theory (DFT) combining with the non-equilibrium Green functions (NEGF) method is applied to the study of the electronic transport properties for a Di-thiol-benzene (DTB) molecule coupled to two Au(111) surfaces. The dependence of the transport properties on the bias, the coupling geometry of the molecule-electrode interface, and the intermolecular interaction are examined in detail. The results show that the existence of the hydrogen atom at the end of the DTB molecule would significantly decrease the transmission coefficients, and then the differential conductance (dI/dV). By changing the position of the DTB molecule located between two electrodes a maximum value of calculated current is observed. It is also found that the intermolecular interaction will strongly influence the transport properties of the system studied.

关键词： non-equilibrium Green functions method, transmission spectrum, the molecular projected selfconsistent Hamiltonian, projected density of state.

Nucleon Form Factors and N-A Transitions in a Hypercentral Constituent Quark Model with Meson Cloud

在线全文

学校读者我要写书评

暂无评论

Communications in theoretical physics 2007年第3期 539-546页

作者： CHEN Dina-Yong~(1,2. DONG Yu-Bing~(1,+)1 institute of High Energy physics,the {2.,Beijing 100049,china2.Graduate School of the {2.,Beijing 100049,china institute of High Energy physics，the {2.，Beijing 100049，china Graduate School of the chinese academy of sciences，Beijing 100049，china institute of High Energy physics，the {2.，Beijing 100049，china

We study the nucleon form factors and the nucleon-△(12.2.transitions in a framework of hypercentralconstituent quark *** pion meson cloud effect is taken into account *** results show that the pioncloud contributes substantially to the nucleon form factors as well as to the helicity amplitudes of △(12.2.,and it givesan improved agreement compared to the experimental measurement.

关键词： electromagnetic form factor nucleon and △(12.2. hypercentral constituent quark model meson cloud