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science china(Technological sciences) 2005年第5期48卷 510-520页

作者： SU Juanhua1,2. LIU Ping2. DONG Qiming2.& LI Hejun1 1. College of Materials science and engineering, Northwestern Polytechnical {2., Xi’an 710072. china 2. College of Materials science and engineering, Henan {2. of science and technology, Luoyang 471003, china 1. College of Materials science and engineering Northwestern Polytechnical University 710072 Xi’an China 2. College of Materials science and engineering Henan University of Science and Technology 471003 Luoyang China

The thermomechanical treatment process is effective in enhancing the properties of the lead frame copper alloy. In this study, an optimal pattern of the thermomechanical processes for Cu-Cr-Zr was investegated using an intelligent control technique consisting of neural networks and genetic algorithms. The input parameters of the artificial neural network (ANN) are the reduction ratio of cold rolling, aging temperature and aging time. The outputs of the ANN model are the two most important properties of hardness and conductivity. Based on the successfully trained ANN model, genetic algorithms (GA) are used to optimize the input parameters of the model and select perfect combinations of thermomechanical processing parameters and properties. The good generalization performance and optimized results of the integrated model are achieved.

关键词： Cu-Cr-Zr alloy, thermomechanical processing optimization, artificial neural network, genetic algorithms.

Algorithm of graph isomorphism with threedimensional DNA graph structures

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Progress in Natural science:Materials International 2005年第2期15卷 86-89页

作者： LIU Guangwu 1,2., YIN Zhixiang 1,3, XU Jin1 and DONG Yafei1(1. Department of Control science and engineering, Hua Zhong {2. of science and technology, wuhan 43.074, china 2. College of Transportation, wuhan {2. of technology, wuhan 430063, china 3. Department of Mathematics and Physics, Anhui {2. of science and technology, Huainan 2.2.01, china) Department of Control science and engineering Hua Zhong University of Science and Technology Wuhan 430074 China. College of Transportation Wuhan University of Technology Wuhan 430063 China. Department of Mathematics and Physics Anhui University of Science and Technology Huainan 232001 China

An algorithm for solving the graph isomorphism problem with 3-D DNA structures is proposed in this paper. The k-armed branched junction molecules are used to code k-degree vertices. Double stranded molecules are used to code edges. Then the molecules are mixed in a tube to be ligated. The result can be detected by gel electrophoresis. The time complexity of the algorithm is O(n2., where n is the number of vertices of the graph.

关键词： DNA computing DNA graph structure graph isomorphism

On the new results of global attractive set and positive invariant set of the Lorenz chaotic system and the applications to chaos control and synchronization

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science in china(Series F) 2005年第3期48卷 304-321页

作者： LIAO Xiaoxin 1, 2. 3 , FU Yuli 4 & XIE Shengli 4 1. Department of Control science & Control engineering, {2. university of science & technology, wuhan 43.074, china 2. School of Automation, wuhan university of science & technology, wuhan 430070, china 3. School of Information, Central South university of Economy, Politics and Law, wuhan 430064, china 4. School of Electronics & Information engineering, South china university of technology, Guangzhou 510640, china Correspondence should be addressed to Liao Xiaoxin (email: xiaoxin_liao@***) 1. Department of Control science & Control engineering Huazhong University of Science & Technology 430074 Wuhan China 2. School of Automation Wuhan University of Science & Technology 430070 Wuhan China 3. School of Information Central South University of Economy Politics and Law 430064 Wuhan China 4. School of Electronics & Information engineering South China University of Technology 510640 Guangzhou China

Constructing a family of generalized Lyapunov functions, a new method is proposed to obtain new global attractive set and positive invariant set of the Lorenz chaotic system. The method we proposed greatly simplifies the complex proofs of the two famous estimations presented by the Russian scholar Leonov. Our uniform formula can derive a series of the new estimations. Employing the idea of intersection in set theory, we extract a new Leonov formula-like estimation from the family of the estimations. With our method and the new estimation, one can confirm that there are no equilibrium, periodic solutions, almost periodic motions, wandering motions or other chaotic attractors outside the global attractive set. The Lorenz butterfly-like singular attractors are located in the global attractive set only. This result is applied to the chaos control and chaos synchronization. Some feedback control laws are obtained to guarantee that all the trajectories of the Lorenz systems track a periodic solution, or globally stabilize an unstable (or locally stable but not globally asymptotically stable) equilibrium. Further, some new global exponential chaos synchronization results are presented. Our new method and the new results are expected to be applied in real secure communication systems.

关键词： Lorenz chaotic system global attractive set positive invariant set globally exponential tracking globally exponential synchronization.

YIELD CRITERION IN PLASTIC-DAMAGE MODELS FOR CONCRETE

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Acta Mechanica Solida Sinica 2010年第3期23卷 220-230页

作者： Ji Zhang Zhongxian Zhang~★Chuanyao Chen (School of Civil engineering and Mechanics,huazhong {2. of science and technology, wuhan 43.074,china) [a] School of Civil engineering Mechanics Huazhong University of Science technology Wuhan 430074 China

A class of plastic-damage models for concrete require an unambiguous definition of cohesion in the yield criteria. For this reason, the Lubliner yield criterion has been adopted by many investigators and the commercial FE program Abaqus. As is well known, this criterion has achieved great success especially in plane stress states. In this paper, we are trying to extend it to triaxial compression stress states. First, a major limitation of the Lubliner criterion is analyzed. Then, a revised version of the Lubliner criterion is proposed, which shows appropriate properties over a wide range of stress states often encountered in engineering structures, and the predicted failure envelopes fit well with experimental data. For the concrete damaged plasticity model in Abaqus, a calibration strategy is suggested for uniformly confined concrete.

关键词： plastic-damage model Lubliner yield criterion triaxial compression concrete damaged plasticity

Cu+Al_2._3 composite coating on AISI 1045 steel surface by laser cladding

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中国有色金属学会会刊：英文版 1999年第3期9卷 462-467页

作者： Wang Maoqiu(王毛球), Xie Changsheng(谢长生), Zeng Dawen(曾大文) School of Materials science and engineering,{2., wuhan 43.074, P. R. china huazhong Univ Sci & Technol Sch Mat Sci & Engn Wuhan 430074 Peoples R China

Perfect composite coatings have been successfully produced with preplaced mixture of Cu+Al 2. 3(2.～2.%) on AISI 1045 steel substrate by using a 2.kW CO 2.laser. A suitable amount of Al 2. 3 in Cu as additive can improve the processing conditions of laser cladding. Fe rich particles were observed in the clad layer during microstructural observation with SEM and chemical composition analysis by EDAX. The experimental results showed that microhardnesses of the coatings were over 150HV 0.05 and the electric resistivities were about 4.0×10 -8 ～4.5×10 -8 Ω·m. Perfect composite coatings have been successfully produced with preplaced mixture of Cu+Al 2. 3(2.～2.%) on AISI 1045 steel substrate by using a 2.kW CO 2.laser. A suitable amount of Al 2. 3 in Cu as additive can improve the processing conditions of laser cladding. Fe rich particles were observed in the clad layer during microstructural observation with SEM and chemical composition analysis by EDAX. The experimental results showed that microhardnesses of the coatings were over 150HV 0.05 and the electric resistivities were about 4.0×10 -8 ～4.5×10 -8 Ω·m.

关键词： laser cladding conductive coating microhardness tests resistance

Statistical damage detection method for frame structures using a confidence interval

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Earthquake engineering and engineering Vibration 2010年第1期9卷 133-140页

作者： Li Weiming,Zhu Hongping~(++),Luo Hanbin~(++) and Xia Yong~(++) School of Civil engineering and Mechanics,huazhong {2. of science and technology,wuhan 43.074,china ~+PhD Candidate ++ Professor School of Civil engineering and Mechanics Huazhong University of Science and Technology Wuhan China

A novel damage detection method is applied to a 3-story frame structure, to obtain statistical quantification control criterion of the existence, location and identification of damage. The mean, standard deviation, and exponentially weighted moving average （EWMA） are applied to detect damage information according to statistical process control （SPC） theory. It is concluded that the detection is insignificant with the mean and EWMA because the structural response is not independent and is not a normal distribution. On the other hand, the damage information is detected well with the standard deviation because the influence of the data distribution is not pronounced with this parameter. A suitable moderate confidence level is explored for more significant damage location and quantification detection, and the impact of noise is investigated to illustrate the robustness of the method.

关键词： damage detection standard deviation statistical method confidence interval noise

Crystallization and Electrical Properties of (Ba_(0.4)Pb_(0.3))Sr_(0.3)TiO_3 Thin Film by Pulsed laser Deposition

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Journal of wuhan university of {2.(Materials science) 2007年第4期22卷 634-637页

作者：杨卫明 Department of Electronic science and technology Huazhong University of Science and Technology

（Ba0.4Pb0.3）Sr0.3TiO3 thin films were fabricated via pulsed laser deposition （PLD） technique on Pt/TiO2.SiO2.Si substrate. The crystallization of the films was characterized by XRD and FSEM, and the experimental results suggested deposition parameters, especially the deposition temperature was the key factor in forming the perovskite structure. The dielectric properties of the film deposited with optimized parameters were studied by an Agilent 42.4A impedance analyzer at 1 MHz. The dielectric constant was 772. and the loss tangent was 0.006. In addition, the well-shaped hysteresis loop also showed that the film had a well performance in ferroelectric. The saturated polarization P, remnant polarization Pr and coercive field E were about 4.6 μC/cm2. 2.5 μC/cm2.and 2. kV/cm （the coercive voltage is 0.7 V）, respectively. It is suggested the film should be a promising candidate for microwave applications and nonvolatile ferroelectric random access memories （NvFeRAMs）.

关键词： (Ba0.4Pb0.3)Sr0.3TiO3 thin film PLD dielectric properties ferroelectric properties

Early Age Properties of Cementitious Materials by Electrical Resistivity Measurement

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Journal of wuhan university of {2.(Materials science) 2010年第4期25卷 641-644页

作者：魏小胜 School of Civil engineering and Mechanics Huazhong University of Science and Technology

Three cement pastes were prepared with the fixed water-binder ratio and different fly ash contents. The compression test and electrical resistivity measurement of the paste mixes were conducted during 48 h. The changes of the CH content and the non-evaporable water content in the cement-fly ash hydration systems with time were obtained by the thermal gravimetric analysis. The experimental results show that dilution effect of fly ash as micro-filler is dominant mechanism before 48 h, which appears to decrease in the CH content and the non-evaporable water content, also in compressive strength and electrical resistivity, with the increase of fly ash replacement. The relationships between CH content, non-evaporable water content and electrical resistivity show that electrical resistivity can be the indicators of hydration products CH and non-evaporable water. The correlation of the compressive strength fc and the electrical resistivity ρcan be obtained as fc=8.342.ρ=6.7088 for the period of 48 h. The early age compressive strength can then be predicted by electrical resistivity measurement.

关键词： electrical resistivity fly ash compressive strength hydration

Electrical Measurement to Assess Hydration Process and the Porosity Formation

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Journal of wuhan university of {2.(Materials science) 2008年第5期23卷 761-766页

作者：魏小胜 Department of Civil engineering Huazhong University of Science and Technology

The change of electrical resistivity with time at early ages was used to investigate the hydration process and the porosity development. Porosity reduction process of cement-based materials hydration was developed by a proposed method. The porosity reduction is fast at the setting period. The results find that the pore discontinuity occurs faster at lower water/cement ratios than at higher water/cement ratios which is similar to the results of the Percolation method.

关键词： electrical resistivity hydration setting time percolation

Tissue P systems with cell separation: attacking the partition problem

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science china(Information sciences) 2011年第2期54卷 293-304页

作者： ZHANG XingYi1, WANG Shuo2. NIU YunYun2.& PAN LinQiang2.1Key Lab of Intelligent Computing and Signal Processing of Ministry of Education, School of Computer science and technology, Anhui {2., Hefei 2.0039, china 2.mage Processing and Intelligent Control Key Laboratory of Education Ministry of china, Department of Control science and engineering, huazhong university of science and technology, wuhan 43.074, china 1. Key Lab of Intelligent Computing and Signal Processing of Ministry of Education School of Computer Science and Technology Anhui University Hefei 230039 China2. Image Processing and Intelligent Control Key Laboratory of Education Ministry of China Department of Control Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China

Tissue P systems are distributed parallel and non-deterministic computing models in the framework of membrane computing, which are inspired by intercellular communication and cooperation between neurons. Recently, cell separation is introduced into tissue P systems, which enables systems to generate an exponential workspace in a polynomial time. In this work, the computational power of tissue P systems with cell separation is investigated. Specifically, a uniform family of tissue P systems with cell separation is constructed for effciently solving a well-known NP-complete problem, the partition problem.

关键词： membrane computing tissue P system cell separation partition problem