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STUDY ON THE STABILITY OF GOLDEN SECTION ADAPTIVE CONTROL systems BASED ON CHARACTERISTIC MODELLING

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STUDY ON THE STABILITY OF GOLDEN SECTION ADAPTIVE CONTROL SY...

Syntheses, Crystallographic and Magnetic Properties of Nd_3Fe_(29-x)Cr_x and Other Associated Compounds

第11届国际模糊系统协会世界大会

作者： Duoqing SUN Hongxin WUbeijing Institute of Control Engineering chinese academy of Space Technology beijing 100080 china Department of mathematics & Physics Hebei Normal University of science & Technology Qinhuangdao 066004 china

＜正＞ The method of characteristic modelling provides a theoretical foundation for the designs of intelligent controllers and the control of higher-order plants by using lower controllers. However, for any linear time-invariant higher order plant with unknown parameters and order, the stability analysis of the adaptive control systems based on characteristic modelling is still an open question in general case. Based on Lyapunov’s direct method for time-variant discrete systems, this paper gives the conditions for the uniformly asymptotic stability of the golden section adaptive control systems based on characteristic modelling. The given conditions are only related to the variable rates of the closed-loop system parameters. The result in this paper can be used to analyze quantitatively the stability of time-variant discrete systems.

关键词： golden section adaptive control characteristic modelling asymptotic stability.

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Journal of Materials science & Technology 2000年第3期16卷 261-268页

作者： Xiufeng HAN and Terunobu Miyazaki (Department of Applied Physics, Faculty of Engineering, Tohoku University, Sendai 980-77, Japan) Qiyuan WANG, Jun WANG, Yude ZAN and Lanying LIN (Material science Center, Institute of Semiconductors, chinese academy of Sc Department of Applied Physics Faculty of Engineering Tohoku University Sendai 980-77 Japan Material science Center Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China

A systematic study of syntheses and magnetic properties of the Nd_3Fe_(29-x)Cr_x (x=4.5, 4.7, 5.0, and 5.5) compounds has been performed. The single-phase compounds of Nd_3Fe_(29-x)Cr_x can be formed in the range 4.5≤ x ≤ 5.5. The Curie temperature T_C, the saturation magnetization M_s at 4.2 K, the anisotropy field H_A at 4.2 K and room temperature. and the intra-sublattice exchange coupling parameter j_(FeFe) at 4.2 K for the Nd_3Fe_(29-x)Cr_x compounds decrease with increasing Cr composition from x=4.5 to 5.5, respectively. Nitrogenation and carbonation, unlike hydrogenation. result mainly in improvements of the Curie temperature, the saturation magnetization and the anisotropy field at 4.2 K and room temperature for the Nd_3Fe_(29-x)Cr_x compounds compared with their parent compounds.

关键词： Fe Crystallographic and Magnetic Properties of Nd3Fe x)Cr_x and Other Associated Compounds Syntheses Nd

ADMISSIBILITY AND Г-MINIMAXITY OF LOSSESTIMATORS IN MULTIVARIATE LINEAR MODEL

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systems science and Mathematical sciences 1998年第1期11卷 69-81页

作者： Kazuo Noda(Department of mathematics, science University of Tokyo, Tokyo, Japan 162)WU Qiguang(Institute of Systetns science, Academia Sinica, beijing 100080, china)

Let an n x m matrix of observations, Y, have distribution N(XB, G V),where X, G > 0 and V > 0 are known n x p) n x n and m x m matrices respectively,B is an unknown P x m matrix of parameters. We consider the problem of estimatingthe loss L = (SXB - SXB)C(SXB - SXB)’, where S and C > 0 are known t x n andm x m matrices respectively B = (X’G-’X)-X’G-’y It is pr0ved that the uniformlyminimum risk unbiased estimator of L, L. = (trCV)SX(X’G-’X)-X’S’, is admissiblefor q = rankSX = 1 and m 4, or for q 2 and m 2 and inadmissible for m 5 witha matrix loss function. It is also shown that the above Lo is a r-minimax estimator 0f Lagainst a class of priors.

关键词： Admissible loss estimator r-minimax loss estimator matrix loss function.

Experimental Study of the Influence of Hydrous Minerals on the Melting Behaviour of Rocks at High Temperatures and Pressures

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Acta Geologica Sinica(English Edition) 1996年第2期70卷 157-167页

作者： Zheng Haifei Xie Hongsen Xu Yousheng Song Maoshuang Zhang Yueming Wang Mingzai and Xu Huigang Department of Geology, Peking University, beijing Institute of Geochemistry, chinese academy of sciences, Guiyang,Guizhou

The experimental study on the melting of potassic basalt and eclogite with about 2% waterat 800-1300℃ and 1.0-3.5 GPa shows that the solidi of both rocks are significantly lower thanthose obtained from the previous experiments of the same type of rocks under dry conditions,and the former which is enriched in potassium has a lower melting point than the latter. It is con-sistent with the previous study. The melting temperature of eclogite increases with pressure,whereas potassic basalt has similar properties only at 1.5—2.5 GPa and>3.0 GPa, and at 2.5—3.0 GPa the melting temperature decreases with pressure. This can be explained as follows: (1)eclogite only has one hydrous mineral amphibole and the dehydous temperature is lower than thewet solidus of the rock. (2) Amphibole exists in potassic basalt at the pressures lower than 2.5GPa and phlogopite exists at pressures higher than 2.5 GPa, and the special compositions of bothminerals determine that amphibole has a dehydration temperature higher than or close to that ofthe wet solidus of the rocks, while phlogopite has a dehydration temperature lower than that ofthe wet solidus. On the other hand the features of the continuous solidus in the experiment ofhydrous eclogite were produced by the fact that the dehydration temperature of its amphibolelower than or close to the melting temperature of the hydrous conditions. So the melting tempera-ture lowers at higher pressures. Therefore, the composition of the rocks in the lithosphere and thetypes of hydrous minerals and their stable P-T conditions are the important factors controllingthe solidi of rocks. It can quite well explain the partial melting of rocks and the origin of the lowvelocity zone in the deep lithosphere.

关键词： high-T/P hydrous minerals melting point of rock experimental condition

Development of a Wire Driven Robot for Grinding with Stiffness Adapted

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Development of a Wire Driven Robot for Grinding with Stiffne...

Mn_(12)-Ac磁性分子团簇单晶的热重-差热分析与结构转变

第十届国际制造工程与管理会议

作者： ZHANG Bo, ZHAO Ming-yang(1. Graduate School of the chinese academy of sciences, beijing 100039, china 2. Robotics Laboratory, Shenyang Institute of Automation, chinese academy ofsciences, Shenyang 110016, china)

＜正＞ Along with development of new design and machining method production with more complex surface can be manufactured. Researching on the new equipment used for surface disposal has become the important matter. Grinding and polishing are a common surface processing method. A new type wire driven parallel robot used for grinding processing is proposed in this paper. Wire driven parallel robot is developed from parallel robot and serial wire driven robot. Steel wire is used to replace the leg of parallel robot. Compared with parallel robot, this kind of robot has lager workspace, lower weight, higher rigidity and higher load/deadweight ratio. And the stiffness of robot is controlled by changing the tension of wire. The robot proposed in this paper has three DOF. The moving part is driven by four wires, three of them are used to drive and the rest to keep them tension, with a restraining machine. The position sensors are installed in restraining machine. The position of terminating of end-effecter can be ascertained in the space. The tension sensors are installed in each wire to form force feedback system. By changing the tension the force on the workpiece can be controlled. Also the stiffness of robot can be adjusted.

关键词： wire driven parallel robot stiffness control

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物理学报 2004年第11期53卷 4015-4020页

作者：刘颖葛培文苏少奎张丽娟王云平中国科学院物理研究所北京100080 北京化工大学理学院北京100029

通过热重差热分析 (TG DTA) ,考察了Mn1 2 Ac磁性分子晶体从室温到 2 70℃的热失重过程 .结合x射线粉末衍射分析 ,认为在第一个失重阶段 ,即 2 5— 110℃ ,Mn1 2 Ac失去了处于团簇分子间隙的结晶乙酸和结晶水 ,同时失去了团簇分子中... 详细信息

通过热重差热分析 (TG DTA) ,考察了Mn1 2 Ac磁性分子晶体从室温到 2 70℃的热失重过程 .结合x射线粉末衍射分析 ,认为在第一个失重阶段 ,即 2 5— 110℃ ,Mn1 2 Ac失去了处于团簇分子间隙的结晶乙酸和结晶水 ,同时失去了团簇分子中与 4个Mn3+ 配位的 4个H2 O ,Mn1 2 Ac单晶结构被破坏 ,但是团簇分子的基本结构依然存在 ;在第二个失重阶段 ,即 180— 2 30℃ ,Mn1 2 Ac转变为γ Mn2 O3,其中混有少量Mn3O4 .

关键词：分子团簇磁性配位单晶结构 TG-DTA 分子间分子晶体热重-差热分析热失重乙酸

Sorption behavior of U(VI), ^(234)U(VI) and ^(238)U(VI) onto fracture-filling clays in Beishan granite, Gansu: Application to selecting the site of high-level radwaste repository in china

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science china Earth sciences 2005年第10期48卷 1649-1655页

作者： MIN Maozhong1,2, LUO Xingzhang3, WANG Ju4, JIN Yuanxin4 & WANG Rucheng1 1. Department of Earth sciences, State Key Laboratory of Mineral Deposit Research, Nanjing University, Nanjing 210093, china 2. Center of Materials Analysis, Nanjing University, Nanjing 210093, china 3. Department of Environmental science and Engineering, Nanjing University, Nanjing 210093, china 4. beijing Geology Institute, Nuclear Industry, beijing 100029, china Department of Earth sciences State Key Laboratory of Mineral Deposit Research Nanjing University Nanjing China Center of Materials Analysis Nanjing University Nanjing china Department of Environmental science and Engineering Nanjing University Nanjing china beijing Geology Institute Nuclear Industry beijing china

The first results of sorption experiments of U(VI), 234U(VI) and 238U(VI) onto original (unpurified) fracture-filling clays from No.1 monzonitic granite intrusion, Beishan area, Gansu Province, china are reported. The monzonitic granite intrusion is a potential location for a high-level radwaste (HLW) repository in china. The present experimental results show that the maximum U(VI) sorption reached 92% at near-neutral pH and the distribution coefficient (Kd) was 1226 mL/g. A high sorption capacity of the fracture-filling clays in host rock on radioactive ele-ments is necessary for HLW deep geological disposal repository. No preferential sorption of 234U onto the clays was found. Finally, the sorption of U(VI) onto the clays was also modeled using a surface complexation model.

关键词： HLW geological disposal repository, granite, uranium, radionuclide, clay, sorption.

Stress Corrosion Cracking and Passive Film-inducedTensile Stress in α-Ti

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Journal of Materials science & Technology 2001年第4期17卷 413-416页

作者： Hong LU Kewei GAO, Hui LIU Lijie QIAO and Wuyang CHU Dept. of Materials Physics, University of science and Technology beijing, beijing 100083, china Univ Sci & Technol beijing Dept Mat Phys Beijing 100083 Peoples R China

α-Ti foil with a protective layer formed on one side was deflected during corrosion in a methanol solution containing 0.6 mol/L KCI and then a tensile stress was generated at or near the metal passive film interface. The in situ TEM observation showed that corrosion process could facil- itate dislocation emission and motion. Adding 10% H2O into the methanol solution decreased the passive film-induced stress from 320 MPa to zero, and the susceptibility to SCC measured in slow strain rate tests decreased correspondingly from 98% to zero.

关键词： Ti Stress Corrosion Cracking and Passive Film-inducedTensile Stress in SCC

DETERMINATION OF ACTIVITY OF AI IN SOLID Cu-Al ALLOYS

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Acta Metallurgica Sinica(English Letters) 1989年第11期2卷 360-363页

作者： ZHANG Qianxiang, University of science and Technologys beijing, beijing, china

Activities and activity coefficients of Al in solid Cu-AI alloys have been determined by means of solid electorlyte galvanic cells Al(a_1 , in alloy), Al_2O_3 | ZrO_2· Y_2O_3 | Ni, NiO and Al(a_1 , in alloy), Al_2O... 详细信息

关键词： Cu-Al alloy Al activity activity coefficient solid electrolyte galvanic cell