Robust H_∞ control for uncertain systems with heterogeneous time-varying delays via static output feedback

This paper is concerned with the problem of robust H∞ control for a novel class of uncertain linear continuous-time systems with heterogeneous time-varying state/input delays and norm-bounded parameter uncertainties.The objective is to design a static output feedback controller such that the closed-loop system is asymptotically stable while satisfying a prescribed H∞ performance level for all admissible uncertainties.By constructing an appropriate Lyapunov-Krasvskii functional,a delay-dependent stability criterion of the closed-loop system is presented with the help of the Jensen integral inequality.From the derived criterion,the solutions to the problem are formulated in terms of linear matrix inequalities and hence are tractable numerically.A simulation example is given to illustrate the effectiveness of the proposed design method.     

Small Compact Perturbation of Operators in B∞（Ω）

Abstract： We consider an approximation problem related to strongly irreducible operators, that is, does the direct sum of a strongly irreducible operator in B∞（Ω） and certain operator have a small compact perturbation which is a strongly irreducible operator in B∞（Ω）？ In this paper, we prove that the direct sum of any strongly irreducible operator in B∞（Ω） and certain biquasitriangular operator have small compact perturbations which are strongly irreducible operators in B∞（Ω）.     

变时滞不确定线性系统的H_\infty控制

对于一类不确定状态时变时滞系统,利用基于时滞划分的Lyapunov-Krasovskii泛函讨论其稳定性,并得到以LMI形式给出的一种保守性小的稳定性条件,最后通过分析并给出了保证系统鲁棒稳定的H_\infty控制器,数值实例表明了方法的有效性.     

Electron Transfer Reaction between M-C_6H_6 and M~ -C_6H_6 Complexes in the Gas Phase: Density Functional Theory Study

Significant progress has been made in understanding the nature of the transition state andthe paths for electron transfer, especially the influences of environmental factors and themolecular properties on the electron transfer rate. These classical and semi-classical, aswell as quantum-mechanical theory, have been very successful in rationalizing severalstructure-reactivity relationships and in predicting novel features of reactivity. Thesemodels established some links between the electron tra…     

一类非线性时滞系统与时滞相关的H_∞控制

考虑一类非线性时滞系统的H∞控制.并对非线性项给出了一个新假设,在其假设下利用线性矩阵不等式方法得到了与时滞相关的H∞控制,同时也得到了该类非线性时滞系统鲁棒镇定的充分条件.     

一类切换线性系统的动态输出反馈H_∞控制:LMIs方法

研究一类由任意有限多个线性子系统组成的切换系统的动态输出反馈H∞控制问题.利用共同Lyapunov函数方法和凸组合技术,给出由矩阵不等式表示的控制器存在的充分条件,并设计了相应的子控制器和切换规则.采用消元法,将该矩阵不等式转化为一组线性矩阵不等式(LMIs).最后给出一个数值仿真实例证明结论的有效性.     

FINITE ELEMENT MODELING AND ROBUST VIBRATION CONTROL OF TWO-HINGED PLATE USING BONDED PIEZOELECTRIC SENSORS AND ACTUATORS

Active vibration control for a kind of two-hinged plate is developed in this paper. A finite element model for the hinged plate integrated with distributed piezoelectric sensors and actuators is derived, including bending and torsional modes of vibration. In this model, the hinges are simplified as regular plate elements to facilitate operation. The state space representations for bending and torsional vibrations are obtained. Based on two low-order models of the bending and torsional motion, two H ∞ robust controllers are designed for suppressing the vibrations of the bending and torsional modes, respectively. The simulation results indicate the effectiveness and feasibility of the designed H ∞ controllers. The vibration magnitudes of the low-order modes can be reduced without affecting the high frequency modes.     

低能电子被水分子散射总截面的计算

基于固定核近似原理,利用R矩阵方法和分子的R矩阵程序计算了在4-20 eV能量范围内电子被水分子弹性散射的总碰撞截面,同时讨论了R矩阵半径的取值对总截面的影响.并将结果与实验值及其它理论计算作了比较,结果显示这种计算方法对于电子分子碰撞是很有效的.     

光助/H2O2/草酸铁处理垃圾渗滤液

利用光助／H2O2／草酸铁处理已经过生化处理的垃圾渗滤液(CODcr=450mg／L左右)时，采用365nm、125W的UV灯照射下，光强为Iu=2．9mW／cm^2时，反应较佳条件是pH值=4．0左右及总药剂用量为1．4％(体积比)。草酸铁的用量要适当，投加量过少，混凝效果较差，有效光子不能完全转化为化学能，处理效果不理想；投加量过多，溶液形成棕色浑浊，使紫外光的吸收降低，造成光散射，降低反应速度。而H2O2的投加量过多，将使铁的络合物更加稳定，H2O2的分解速率受到限制，投加量过少，效果也会降低。当总药剂用量为1．4％(体积比，其中30％过氧化氢0．6％，0．1mol／L草酸铁溶液0．8％)时，反应30min后，CODcr去除率可达80％左右，脱色率可达90％以上。     

蓝色铬膜层的电沉积机理

本文通过对蓝色铬膜层的XPS分析及电化学方法研究了该膜层的沉积过程。结果表明,整个膜层可分为:120nm厚的交界层(主要成分是Cr和基底Ni),250nm厚的中间层(Cr_2O_3,Ct和CtSe,后者决定了膜层呈蓝色),以及100nm厚的表面层(吸附的Cr(Ⅵ)、Cr(Ⅲ),SeO_4~(2-)和Se),对电沉积历程和机理进行了探讨。