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Spectral Analysis and Variable Structural Control of an Elastic Beam

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Journal of Applied Mathematics and Physics 2013年第5期1卷 98-104页

作者： xuezhang hou Mathematics Department Towson University Baltimore USA

An elastic beam system formulated by partial differential equations with initial and boundary conditions is investigated in this paper. An evolution equation corresponding with the beam system is established in an appropriate Hilbert space. The spectral analysis and semigroup generation of the system operator of the beam system are discussed. Finally, a variable structural control is proposed and a significant result that the solution of the system is exponentially stable under a variable structural control with some appropriate conditions is obtained.

关键词： Spectral Analysis Semigroups of Linear Operators Elastic Beam System Variable Structural Control

The Controllability of Cartesian Flexible Robot System

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Systems Science and Systems Engineering 1996年第2期6卷 240-245页

作者： WANG Zheng LIN Xianning hou xuezhang(Department of Mathematics, Northeast NOrmal University, Changchun, 130024)

The control system of X-Y Catesian flexible robot is considered in present *** have established the evolution equation model in an appropriate Hilbert space for the system of one-link flexible arm with payload, and us... 详细信息

关键词： flexible robot control system controllability

Variable　Structure　Control　of　Distributed　Parameter　Systems　and　Application　to　the　System　of　Heat　Process

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Systems Science and Systems Engineering 1994年第3期4卷 257-262页

作者： ZHAO Wenrong Department of Mathematics,Ningxia Education College,Yinchuan,750002 hou xuezhang Department of Mathematics,Northeast Normal University,Changchun,130024

The variable structure control problems of distributed parameter system are in vestrigated in this *** the conditions more general than in[1],[2],the equivalent, control theorem is ***,as an application to system of heat process,we give some conditons for sliding model such that the solution of system of heat process is exonentially stable unde the variable structure control.

关键词： distributed parameter system sliding mode variable structure control heat process

A Control Problem for Nonstationary Population Systems

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Systems Science and Systems Engineering 1994年第1期4卷 66-73页

作者： WANG Hui(Department of Mathematics.Harbin Normal University,Harbin 150080)hou xuezhang(Deparfment of Mathematics,Northeast Normal University,Changchun 130024)

In this paper,we study the nonstationary population control systems:We regard the female-sum fertility rate β(t) as control auction ac judge its optimality by"norm minimum",and discuss the minimum norm control problems for the above population control *** space L2(0,T)’s reflexivity,smoothness and strict convexity,we prove the existence,the uniqueness and the approximation property of the minimum norm control for the nonstationary population control systems and give the corresponding optimality conditions by means of the methods of the dial mapping of Banach space.

关键词： variable population systems minimum norm control female-sum fertility rate dual mapping

Research on an Elastic Robot Control System

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Systems Science and Systems Engineering 1994年第2期4卷 164-171页

作者： hou xuezhang(Department of Mathematics .Northeast Normal University , Changchun 130024. China)WANG Hui(Departnment of Mathematics. Harbin Normal University , Harbin 150080, China)

This paper is concerned with robot control system formulated as a vibrating elasticsystem. We describe this system as all evolution system in an appropriate Hilbert space , and have proved that the posture of the elastic forearm of the robot may arrive at the arbitrary designated place under the given control . and then obtained some asymptotic behavior of the system.

关键词： rebot control system posture arriving at the designated place.

The Reducibility of Closed Operators on Banach Space

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Chinese Quarterly Journal of Mathematics 1989年第2期4卷 49-55页

作者：侯学章东北师范大学数学系

In this paper, having investegated some properties of closed spectral reducible operator on Banach space, we have obtained the necessary and sufficient condition for a closed operator becoming a closed spectral operator. The main results are as follows: (1) Let T be a closed spectral reducible operator, then for any closed subset F of complex plane, We have (2) Let T be a closed operator, then T becomes a closed spectral operator if and only if 1. T is a spectral reducible closed decomposable operator with property (B); 2. for every α∈ρ(T), the spectral measure E(·) of R(a,T) is satisfied with the condition E({0}) =0.

关键词：闭算子 Banach空间可分解算子谱算子扩充复平面闭线性算子解析扩张类算子充分必要条件解析函数

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一类柔性梁系统的谱分析和半群生成(英文)

应用泛函分析学报 2011年第3期13卷 319-331页

作者：侯学章陶森大学数学系美国马里兰州212520001

讨论了一类双臂三关节柔性梁系统的分析问题.首先,建立了一个与柔性梁的偏微分方程组及初值边值条件相应的希尔伯特空间中的一阶发展系统.接着讨论系统算子的谱性质和半群性质.最后借助系统算子的谱性质和半群性质提出并证明了柔性梁系... 详细信息

讨论了一类双臂三关节柔性梁系统的分析问题.首先,建立了一个与柔性梁的偏微分方程组及初值边值条件相应的希尔伯特空间中的一阶发展系统.接着讨论系统算子的谱性质和半群性质.最后借助系统算子的谱性质和半群性质提出并证明了柔性梁系统的指数稳定性.

关键词：柔性梁系统谱分析线性算子半群指数稳定性

Preparation of Laser Cladding Coating Undercooling Cu-based Alloy and Co on Non-equilibrium Solidification Structure

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Journal of Wuhan University of Technology(Materials Science) 2024年第2期39卷 463-472页

作者：田徐铭 CAO Shichao hou Kai hou Xiaopeng WANG Hongfu 张煜 Department of Outpatient Xinzhou People’s HospitalXinzhou 034099China School of Mechanical Engineering North University of ChinaTaiyuan 030051China Department of Neurosurgery Xinzhou People’s HospitalXinzhou 034099China Department of Orthopedics Xinzhou People’s HospitalXinzhou 034099China

The effect of the gradient content of Co element on the solidification process of Cu-based alloy under deep under cooling conditions was *** non-equilibrium solidification structure of the under cooled alloy samples were *** is found that the rapidly solidified alloy has undergone twice grain refinement during the undercooling *** and significance of the maximum undercooling refinement structure of Cu60Ni35Co5 at T=253 K were ***-density defects were observed,such as dislocations,stacking faults networks,and twinning *** standard FCC diffraction pattern represents that it is still a single-phase *** on the metallographic diagram,EBSD and TEM data analysis,it is illustrated that the occurrence of grain refinement under high undercooling is due to stress induced *** addition,the laser cladding technology is used to coat Co-based alloy(Stellite12) coating on 304 stainless steel substrate;the microstructure of the coating cross-section was *** was found that the microstructure of the cross-section is presented as columnar crystals,planar crystals,and disordered growth direction,so that the coating has better hardness and wear *** electrochemical corrosion of the substrate and coating,it can be seen that the Co and Cr elements present in the coating are more likely to form a dense passivation film,which improved the corrosion resistance of the coating.

关键词： non-equilibrium solidification structure undercooling recrystallization laser cladding coating

Herbivore and native plant diversity synergistically resist alien plant invasion regardless of nutrient conditions

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Plant Diversity 2024年第5期46卷 640-647页

作者： Liping Shan Meng hou Key Laboratory of Wetland Ecology and Environment State Key Laboratory of Black Soils Conservation and UtilizationNortheast Institute of Geography and AgroecologyChinese Academy of SciencesChangchun 130102China

Alien plant invasion success can be inhibited by two key biotic factors:native herbivores and plant ***,few studies have experimentally tested whether these factors interact to synergistically resist invasion success,especially factoring in changing global environments(*** enrichment).Here we tested how the synergy between native herbivores and plant diversity affects alien plant invasion success in various nutrient *** this purpose,we exposed alien plant species in potmesocosms to different levels of native plant diversity(4 vs.8 species),native generalist herbivores,and high and low soil nutrient *** found that generalist herbivores preferred alien plants to native plants,inhibiting invasion success in a native *** inhibition was amplified by highly diverse native ***,the amplified effect between herbivory and native plant diversity was independent of nutrient *** results suggest that a higher diversity of native communities can strengthen the resistance of native generalist herbivores to alien plant invasions by enhancing herbivory *** synergistic effect remains in force in nutrient-enriched habitats that are always invaded by alien plant *** results shed light on the effective control of plant invasions using multi-trophic means,even in the face of future global changes.

关键词： Biological invasion Biotic resistance Diversity conservation Plant-herbivore interactions Resource availability Global change