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控制理论与应用（英文版） 2012年第2期10卷 216-222页

作者： Zhiyuan LIU 1 , Guowei FAN 1 , Hong CHEN 2 1.department of control science and engineering, Harbin Institute of Technology, Harbin Heilongjiang 150001, china 2.department of control science and engineering, jilin university, changchun jilin 130025, china department of control science and engineering Harbin Institute of Technology Harbin Heilongjiang China department of control science and engineering Jilin University Changchun Jilin China

Stabilization problem of discrete-time linear switching systems with bounds on the state and control input is solved in this paper. First, the synthesis of state feedback controllers that ensure the stability of closed-loop switching systems is studied under a sufficient condition. By using the idea of positive invariance, a stabilizing controller design methodology is proposed. Based on these results, the convergence rate problem is also discussed. A state feedback controller that guarantees the optimal convergence rate of closed-loop switching systems is obtained via optimization. Finally, an example made up of two subsystems is studied to show the application of our method.

关键词： Switching systems Constraints Stabilization problem Convergence rate problem

Integrative multi-omics approaches reveal that Asian cultivated rice domestication influences its symbiotic relationship with arbuscular mycorrhizal fungi

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Pedosphere 2024年第2期34卷 315-327页

作者： Lei TIAN jilin WANG Hongping CHEN Weiqiang LI Lam-Son Phan TRAN Chunjie TIAN Key Laboratory of Mollisols Agroecology State Key Laboratory of Black Soils Conservation and UtilizationNortheast Institute of Geography and AgroecologyChinese Academy of SciencesChangchun 130102China Rice Research Institute Jiangxi Academy of Agricultural SciencesNanchang 330200China Institute of Genomics for Crop Abiotic Stress Tolerance Department of Plant and Soil ScienceTexas Tech UniversityLubbock TX 79409USA

Potential changes in the symbiotic relationship between rice(Oryza sativa)and microorganisms have occurred during the domestication of Asian cultivated rice(***)from common wild rice(Oryza rufipogon)and in response to global climate change,along with evolving adaptations to the *** potential genes may express differently or dominate the symbiotic relationships between arbuscular mycorrhizal fungi(AMF)and plants,which may be beneficial to rice *** date,research on this important topic has been *** this study,we aimed to examine the symbiotic relationships of Asian common wild and cultivated rice species with *** conducting a comparative metagenomic analysis of the rhizospheres of wild and cultivated rice species,we identified differences in Rhizophagus intraradices-related genes associated with wild and cultivated rice,as well as functional genes of ***,we obtained root-related genes associated with AMF from transcriptome data of rice *** results collectively suggest that ***-related genes in the rhizosphere of wild rice may be more conducive to its ***,bacteria from the Nitrosomonadaceae and Nitrospiraceae families identified in the rhizosphere of wild rice exhibited positive correlations with ***-related genes with protein identifiers 1480749 and1871253,which may indicate that nitrobacteria can enhance the functions of *** in association with wild ***,in a case study using comparative transcriptome analysis of root samples obtained from ***-inoculated wild and cultivated rice plants,we found significantly higher expression levels of the strigolactone pathway-related genes DWARF3(D3)and DWARF14(D14)in ***-inoculated common wild rice than in ***-inoculated cultivated *** study provides a theoretical basis for identifying the effects of domestication on mycorrhizal symbiosis-related genes,which could be promoted in wi

关键词： Rhizophagus intraradices root-related gene symbiotic effect strigolactone wild rice

Robust observer-based control for uncertain discrete-time piecewise affine systems

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控制理论与应用（英文版） 2012年第2期10卷 236-243页

作者： Yahui GAO 1 , Zhiyuan LIU 2 , Hong CHEN 3 1.AVIC (Aviation Industry Corporation of china) china Aviation Motor control System Institute, Wuxi Jiangsu 214063, china 2.department of control science and engineering, Harbin Institute of Technology, Harbin Heilongjiang 150001, china 3.department of control science and engineering, jilin university, changchun jilin 130025, china AVIC (Aviation Industry Corporation of china) china Aviation Motor control System Institute Wuxi Jiangsu China department of control science and engineering Harbin Institute of Technology Harbin Heilongjiang China department of control science and engineering Jilin University Changchun Jilin China

The main contribution of this paper is to present a novel robust observer-based controller design method for discrete-time piecewise affine systems with norm-bounded uncertainties. The key ideas are to construct a piecewise quadratic Lyapunov function to guarantee the stability of the closed-loop systems, approximate polytopic operating regions by ellipsoids, and use the singular value decomposition technique to treat the constraint of matrix equality. It is shown that the suggested control method can be formulated as linear matrix inequalities that are numerically feasible with commer- cially available software. A numerical example is also given to verify the proposed approach.

关键词： Piecewise affine systems Robust control Observer Linear matrix inequality

Kernel model-based diagnosis

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Progress in Natural science:Materials International 2002年第2期12卷 63-67页

作者： OUYANG Dantong(department of Computer science, jilin university, changchun 130012, china) jilin Univ Dept Comp Sci Changchun 130012 Peoples R China

The methods for computing the kernel consistency-based diagnoses and the kernel abductive diagnoses are only suited for the situation where part of the fault behavioral modes of the components are known. The characterization of the kernel model-based diagnosis based on the general causal theory is proposed, which can break through the limitation of the above methods when all behavioral modes of each component are known. Using this method, when observation subsets deduced logically are respectively assigned to the empty or the whole observation set, the kernel consistency-based diagnoses and the kernel abductive diagnoses can deal with all situations. The direct relationship between this diagnostic procedure and the prime implicants/implicates is proved, thus linking theoretical result with implementation.

关键词： model-based diagnosis general causal theory prime implicant/implicate diagnostic space.

PARTICLE DISTRIBUTION IN CENTRIFUGAL ACCELERATING FIELDS

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Chinese Journal of Mechanical engineering 2003年第3期16卷 329-333页

作者： Yu SirongZhang XinpingHe ZhenmingLiu YaohuiCollege of Materials scienceand engineering,jilin university,changchun 130025, china College of Materials science and engineering Jilin University Changchun 130025

Based on continuum theory and moving law of particles, a model is presentedto obtain gradient distribution of particles in centrifugal accelerating field, by which theparticle distribution in gradient composite material can be predicted. The simulation shows withincreases in rotating time, four regions gradually appear from the internal periphery to theexternal one, they are free region, transition region, steady region and surface reinforced region,and the latest three regions are defined as a rich region. Finally, the steady region disappears,and the rich region only includes transition region and surface reinforced region. The influences ofcentrifugal acceleration coefficient G, primary volume fraction phi_0, pouring temperature theta_pand density difference between the particle and the metal matrix on particles gradient distributionare studied in detail. The results of the theoretical analysis agree with experiment ones. Both ofanalysis and experiment results indicate that with the increase in G and theta_p the particledistribution becomes more centralized and the consistence of particle in the surface peripherybecomes larger.

关键词： Centrifugal accelerating field Particles Numerical simulation Functionalgradient material

Effects of different pack aluminizing fillers on the aluminide coatings of Ti-6Al-4V alloy and their high-temperature oxidation behaviors

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Rare Metals 2007年第S1期26卷 306-312页

作者： ZHOU Wei,ZHAO Yuguang,and MEI Xuelian Key Laboratory of Automobile Materials of Ministry of Education,department of Materials science and engineering,jilin university,changchun 130025,china jilin Univ Dept Mat Sci & Engn Key Lab Automobile Mat Minist Educ Changchun 130025 Peoples R China

The aluminide coating process of Ti-6Al-4V alloys with different fillers(100wt.% Al_2O_3,50wt% Y_2O_3+50wt.% Al_2O_3 and 100wt.% Y_2O_3) for improvement of the oxidation resistance were *** results show that the filler does not only participate in the aluminizing process,but also has much effect on the coating *** XRD analysis reveals that the aluminide coating with filler Al_2O_3 is predominant with TiAl_3 and TiAl phases;while the aluminide coatings with filler Y_2O_3+Al_2O_3 are predominant with Ti_3Al *** oxidation kinetics shows that different fillers affect greatly the oxidation resistance of aluminide coating,and the oxidation resistance of aluminized specimens with pack aluminizing filler Al_2O_3 are about 5-8 times than that of the aluminized specimens with other pack aluminizing fillers.

关键词： Ti-6Al-4V alloy aluminide coating fillers oxidation

Efficient computation for dynamic responses of systems with time-varying characteristics

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Acta Mechanica Sinica 2009年第5期25卷 699-705页

作者： Liang Ma Yudong Chen Suhuan Chen Guangwei Meng department of Mechanics, Nanling Campus,jilin university, 130025 changchun, china department of Mechanics Nanling Campus Jilin University 130025 Changchun China

Based on Neumman series and epsilon-algorithm, an efficient computation for dynamic responses of systems with arbitrary time-varying characteristics is investigated. Avoiding the calculation for the inverses of the equivalent stiffness matrices in each time step, the computation effort of the proposed method is reduced compared with the full analysis of Newmark method. The validity and applications of the proposed method are illustrated by a 4-DOF spring-mass system with periodical time-varying stiffness properties and a truss structure with arbitrary time-varying lumped mass. It shows that good approximate results can be obtained by the proposed method compared with the responses obtained by the full analysis of Newmark method.

关键词： Dynamic responses Efficient computation Epsilon-algorithm Time-varying characteristics

DYNAMIC OPTIMIZATION FOR UNCERTAIN STRUCTURES USING INTERVAL METHOD

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Acta Mechanica Solida Sinica 2003年第2期16卷 141-146页

作者： Chen Suhuan Wu Jie Liu Chun (department of Mechanics,jilin university,changchun 130025,china) departmentofMechanics JilinUniversityChangchun130025China

An interval optimization method for the dynamic response of structures with inter- val parameters is *** matrices of structures with interval parameters are ***- bining the interval extension with the perturbation,the method for interval dynamic response analysis is *** interval optimization problem is transformed into a corresponding de- terministic *** the mean values and the uncertainties of the interval parameters can be elected design variables,more information of the optimization results can be obtained by the present method than that obtained by the deterministic *** present method is implemented for a truss *** numerical results show that the method is effective.

关键词： interval optimization interval parameter structure interval extension of function dynamic interval response

STUDY ON ELECTRORHEOLOGICAL FLUID DAMPER FOR APPLICATION IN MACHINING CHATTER control

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Chinese Journal of Mechanical engineering 2003年第1期16卷 13-16页

作者： Yu Junyi Zhang YongliangWang Maohua Zhou XiaoqinFaculty of Mechanical scienceand engineering,jilin university,changchun 130025, china Faculty of Mechanical scienceand engineering Jilin University Changchun 130025

The electrorheological fluid(ERF)is a kind of intelligent material withbright prospects for industry applications, which has viscoelastic characteristic under the appliedelectric field. The dynamic model of a milling system with an ERF damper is established, and thechaffer suppression mechanism of the ER effect is discussed theoretically. Both the theoreticalstudy and the experimental investigation show that the additional damping and additional stiffnessproduced by the ERF increase with the rise in the strength of electric field E, but their influenceon the cuffing stability is different. Only when both additional damping and additional stiffnesscooperate, the milling chatter can be suppressed quickly and effectively. In additional, an ERFdamper used on the arbor of horizontal spindle milling machine is developed, and a series of millingchatter control experiments are performed. The experimental results show that the milling chaffercan be suppressed effectively by using the ER damper.

关键词： Machining chaffer ERF damper Additional damping Additional stiffness Chaffer control

Properties of meso-tetrakis (4-n-alkanoyloxyphenyl) porphyrin liquid crystal Co and Ni complexes

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science china Chemistry 2007年第4期50卷 488-493页

作者： LIU Wei1,2 & SHI TongShun2 1 College of Materials science and engineering, Shandong university of Technology, Zibo 255049, china 2.department of Chemistry, jilin university, changchun 130023, china 1. College of Materials science and engineering Shandong University of Technology Zibo 255049 China 2. department of Chemistry Jilin University Changchun 130023 China

Six series of meso-tetrakis (4-n-alkanoyloxyphenyl) porphyrin Co and Ni complexes (12 kinds) were reported. Nine of the compounds were found to exhibit liquid crystal properties and display a hexagonal columnar discotic columnar (Colh) phase. Molecular structure of all synthesized compounds was confirmed by IR, UV, MS, 1H NIVR, and elemental analysis. These liquid crystalline compounds have been studied by cyclic voltammetry, luminescence, and surface photovoltage spectroscopy.

关键词： porphyrin liquid crystal cyclic voltammetry luminescence surface photovoltage spectroscopy