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3-D Lightning Location Solution and Precision Analysis of Cloud Flash

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wuhan university Journal of Natural {2.s 2009年第3期14卷 241-244页

作者： ZHANG Ping1,2. ZHAO Wenguang2.3?, HU Zhixiang2.3, WEN Yinping2.3 1. School of Architecture and Urban Planning, huazhong university of science and technology, wuhan 430074, Hubei, {2. 2. School of Civil Engineering and mechanics, huazhong university of science and technology, wuhan 430074, Hubei, {2. 3. Hubei Key Laboratory of Control Structure, huazhong university of science and technology, wuhan 430074, Hubei, {2. School of Architecture and Urban Planning Huazhong University of Science and Technology Wuhan 430074 Hubei China School of Civil Engineering and mechanics Huazhong University of Science and Technology Wuhan 430074 Hubei China Hubei Key Laboratory of Control Structure Huazhong University of Science and Technology Wuhan 430074 Hubei China

Using the spatial coordinates of detection stations and the time of arrival of lightning wave, the observation equations can be expressed. For the large lightning detection network, the least square method is used to process the adjustment of observation data to find the most probable value of lightning position, and the result is assessed by the mean error and dilution of precision. Lightning location precision is affected by figure factor. The conclusion can be used in the design of location network, data processing, and data analysis.

关键词： 3-D lightning location cloud flash detection solution model dilution of precision figure factor

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 430074, 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.

Inhibition of ethanol-induced toxicity by tanshinone ⅡA in PC12.cells

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Acta Pharmacologica Sinica 2006年第6期27卷 659-664页

作者： Xian-fang MENG~2.Xiao-jing ZOU~3 Bin PENG~2.Jing SHI~2.Xin-min GUAN~2.Chun ZHANG~(4,5)2.department of Neurobiology,Tongji Medical College,huazhong university of science and technology,{2. 430030,china 3 department of Anesthesiology,4 department of Nephrology,Union Hospital,Tongji Medical College,huazhong university of science and technology,{2. 43002..china department of Neurobiology Tongji Medical College Huazhong University of Science and Technology Wuhan China department of Anesthesiology Union Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan China department of Nephrology Union Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan China

Aim:To observe the effects of tanshinone IIA(Tan IIA)on the neurotoxicityinduced by ethanol in PC 12.cells and to explore its protective ***:PC 12.ell survival was measured by MTT *** formation of reactive oxygenspecies(ROS)and lactate dehydrogenase(LDH)release were detected by 2.,7′-dichlorofluorescin(DCF)fluorescence and calorimetric method,*** of cell apoptosis was monitored by flow *** expression ofp53 was detected by immuno-fluorescence and flow ***:Ethanolsignificantly impaired the survival of PC12.cells as demonstrated by MTT *** also induced significant ROS formation and increased LDH ***-incubation with Tan IIA in the culture medium significantly reversed these *** caused cell apoptosis and the upregulation of p53 *** anti-apoptosis effects of Tan IIA on ethanol-induced toxicity were accompanied by thedownregulation of pro-apoptotic p53 protein ***:Tan IIAcan protect neurons from apoptosis and might serve as a potential therapeuticdrug for neurological disorders induced by ethanol.

关键词： apoptosis ethanol PC12.cells p53 tanshinone ⅡA

Sufficient and necessary conditions for Lyapunov stability of Lorenz system and their application

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science china(Information sciences) 2010年第8期53卷 1574-1583页

作者： LUO Qi 1 , LIAO XiaoXin 2.& ZENG ZhiGang 2.1 College of Information and Control, Nanjing university of Information science and {2., Nanjing 2.0044, china 2.department of Control science and Engineering, huazhong university of science and technology, Image Processing and Intelligent Control Key Laboratory of Education Ministry of china, wuhan 430074, china 1. College of Information and Control Nanjing University of Information Science and Technology Nanjing 210044 China2. Department of Control Science and Engineering Huazhong University of Science and Technology Image Processing and Intelligent Control Key Laboratory of Education Ministry of China Wuhan 430074 China

The sufficient and necessary conditions for Lyapunov stability of the zero equilibrium point of Lorenz system are discussed, and some brief criteria are presented for globally exponential stability, globally asymptotical stability and instability. Furthermore, the behavior of the non-zero equilibrium point of Lorenz system is also investigated, and several sufficient and necessary conditions are provided for locally exponential stability and instability. The established theorems in this paper develop and extend the existing achievements on Lyapunov stability of Lorenz system. In conclusion, by applying the obtained results, some less conservative feedback-control laws are derived to guarantee the globally exponential stability of the chaos control of Chen system, Lu¨ system, Yang-Chen system and Yu-Xia Li system.

关键词： Lorenz system Lyapunov stability sufficient and necessary condition bifurcation values globally exponential synchronization

Ferroelectric properties of Bi_(3.2.)La_(0.75)Ti_(3)O_(12. thin films prepared by sol-gel method

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science china(Technological sciences) 2007年第1期50卷 1-6页

作者： GUO DongYun1, LI MeiYa1, PEI Ling1, YU BenFang1, WU GengZhu1, ZHAO XingZhong1, WANG YunBo2.& YU Jun2.1 department of Physics, wuhan {2., wuhan 430072. china 2.department of Electronic science and technology, huazhong university of science and technology, wuhan 430074, china 1. department of Physics Wuhan University Wuhan 430072 China 2. department of Electronic science and {2. Huazhong University of Science and Technology Wuhan 430074 China

The Bi3.2.La0.75Ti3O12.thin films were fabricated on the Pt/Ti/SiO2.Si substrates using sol-gel method. The structure and morphology of the films were characterized us-ing X-ray diffraction and atomic force microscopy. The thin films showed a perov- skite phase and dense microstructure. The 2.r and 2.c of the Bi3.2.La0.75Ti3O12.thin films annealed at 700℃ were 18.6 μC/cm2.and 4.1 V, respectively, under an applied voltage 10 V. After the switching of 1×1010 cycles, the Pr value decreased to 90% of its pre-fatigue values. The films showed good insulating behavior according to the test of leakage current. The dielectric constant and the dissipation factor of the Bi3.2.La0.75Ti3O12.thin films were about 176 and 0.046 at 1 kHz, respectively.

关键词： Bi3.2.La0.75Ti3O12 thin film sol-gel method ferroelectric properties fatigue leakage current

Design of a 6 DOF Input Device in Telerobotics and Virtual Reality

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Journal of Systems Engineering and Electronics 2002年第2期13卷 36-44页

作者： Peng Gang, Huang Xinhan, Xiong Chunshan & Wang MinControl science and Engineering department, {2., wuhan 430074, P.R. china(Received June 6,2.01) Control science and Engineering department Huazhong University of Science and Technology Wuhan 430074 P. R. China

The pincipl of a 6 DOF (degress of freedom) input device using ultrasonic distance measurement is presented in this paper. The system employs the method of measuring the time of flight. In addition, some techniques, including automatic gain control, self-adaptive variable threshold and temperature compensation, are also used to improve precision. Then, the positions and orientation of the input device can be calculated by the method of spatial analytic geometry. Meanwhile, commands from the 3-D input device are detected and carried out. The validity and precision of the input device are verified by the experiment in a robot system. The proposed device not only can be used for end effector position and orientation measurement in telerobotics, but also can be an interactive device in virtual reality systems, such as helmet tracking, viewpoint navigation and object manipulation.

关键词： Degrees of freedom (mechanics) Three dimensional Ultrasonic applications Virtual reality

WAVE EQUATION MODEL FOR SHIP WAVES IN BOUNDED SHALLOW WATER

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Journal of Hydrodynamics 2000年第4期12卷 109-119页

作者： T.S.Lee Mechanical & Production Engineering department, National university of Singapore, Singapore 11962. Wu Jian kang, Xiong Chuan guang {2. department of huazhong university of science & technology, wuhan 430074, P.R.china C.Shu Mechani Mech. and Production Eng. Dep. Natl. Univ. of Singapore Singapore 119620 Singapore

Ships were modelled as moving pressure disturbances on the free surface of a shallow water basin in the present paper. The moving pressure generating waves were subjected to the reflection of land boundaries and the radiation of open boundaries. This paper proposed and examined a wave equation model (WEM) to solve the shallow water equations with moving surface pressures simulating ship waves in a bounded shallow water region. The Galerkin finite element method was used to solve a second order wave equation for the free surface elevations and the hydrodynamic pressure of the ship bottom simultaneously. Horizontal velocities were obtained from the momentum equations. Numerical solutions of Series 60 C B=0.6 ships moving with the depth Froude number of F h= 0.6, 1.0, 1.3 in a rectangular shallow water harbor were investigated. Three dimensional surface elevation profiles and the depth averaged horizontal velocities were analysed. The numerical results characterised very well the ship waves in shallow water. Strong boundary reflection waves were found in the case of high depth Froude number (F h=1.3). Waves generated by the interactions of two ships moving in the same directions and in the opposite directions were also numerically investigated in the present study.

关键词： ship waves shallow water equations FEH

Anomalous temperature effect of nonlinearity of WO_3 varistor doped with Al_2._3

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Chinese science Bulletin 1999年第7期44卷 671-672页

作者： WANG Yu, Z. Aburas and YAO Kailundepartment of Physics , huazhong university of science and technology, {2., china department of Physics Huazhong University of Science and Technology Wuhan China

MAKAROV and Trontelj first reported the WO3-based low voltage varistor material doped with MnO2.and Na2.O3 in 1994. This material is worth further study because of its low threshold voltage （ 2.3 can obviously improv... 详细信息

MAKAROV and Trontelj first reported the WO3-based low voltage varistor material doped with MnO2./sub> and Na2./sub>CO3 in 1994. This material is worth further study because of its low threshold voltage （ 2./sub>O3 can obviously improve the nonlinearity of WO3-MnO2./sub>-Na2./sub>CO3 series with nonlinear coefficient α≈ 2.and a may be higher than 5 when the amount of Co2./sub>O3 is 1% （mole percentage）. However, the nonlinear characteristic almost vanished when 0.5% Al2./sub>O3 was doped into this system at room temperature, and Al2./sub>O3 showed very stable

关键词： Anomalous temperature effect of nonlinearity of WO3 varistor doped with Al2.3 Al

EXPONENTIAL ESTIMATES FOR STOCHASTIC DELAY EQUATIONS WITH NORM-BOUNDED UNCERTAINTIES

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Journal of Systems science & Complexity 2009年第2期22卷 324-332页

作者： Hongchu WANG Shigeng HU School of Mathematics science South China Normal University Guangzhou 510631 China. department of Mathematics Huazhong University of Science and Technology Wuhan 430074 China.

This paper presents the sufficient conditions for the exponential stability of linear or semi-linear stochastic delay equations with time-varying norm bounded parameter ***-tial estimates for the solutions are also obtained by using a modified Lyapunov-Krasovski *** conditions can be tested numerically using interior point algorithms.

关键词： Exponential estimates time delay uncertainty.