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Journal of Thermal science 1995年第1期4卷 38-43页

作者： Wang Suofang(department of Power engineering,{2. of Aeronautics & Astronautics, 2.0016 {3., China) department of Power engineering Nanjing University of Aeronautics & Astronautics Nanjing China

Natural convection heat transfer in eccentric annuli made of two isothermal horizontal circular cylinders is numerically investigated. Bipolar coordinates are used for the eccentric annuli. The governingequations are transformed into finite difference equations (FDE) by the central difference *** transfer and flow convection pattern results are simulated for 5.0≤RaL≤1.0×105, withPr = 0.3.- 100, Do/Di = 1.2. - 5.0, andε= 0.01-0.95. The axis of the inner cylinder lies onan inclined plane with θp= 0°- 180°.A Mach-Zehnder interferometer is used for the experimentalstudy. The range is for RaL = 5.3.102.2.41×104, with Do/Di = 2.0, 2.5 and 3.12.,ε= 0.0-0.85,and θp= 0°-180°.Air is used as the medium. Comparison of the numerical results with the experimental data shows good agreement.

关键词： natural convection heat transfer eccentric cylinder horizontal annuli.

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 Technology, {2. 2.0044, China 2.{3. of Control science and engineering, Huazhong university of science and Technology, Image Processing and Intelligent Control Key Laboratory of Education Ministry of China, Wuhan 43.074, 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

Molecular dynamics simulations on the structures and properties of ε-CL-2.-based PBXs ——Primary theoretical studies on HEDM formulation design

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science China Chemistry 2007年第6期50卷 737-745页

作者： XU XiaoJuan1,2. XIAO JiJun1, HUANG Hui3. LI JinShan3.& XIAO HeMing1 1 {2. of Chemistry, nanjing university of {2. and Technology, {3. 2.0094, China 2.{2. of Chemistry, Yancheng Teacher’s College, Yancheng 2.4002. China 3.Institute of Chemical Materials, China Academy of engineering Physics, Mianyang 62.900, China department of Chemistry Nanjing University of Science and TechnologyNanjing 210094China department of Chemistry Yancheng Teacher''s CollegeYancheng 224002China Institute of Chemical Materials China Academy of Engineering PhysicsMianyang 621900

Five polymer bonded explosives(PBXs)with the base explosive epsilon-CL-2.(hexanitrohexaazaisowurtzi-tane),the most important high energy density compound(HEDC),and five polymer binders(Estane 5703.GAP,HTPB,PEG,and F_(2.0}4))were *** dynamics(MD)method was employed to investigate their binding energies(E_(bind))2./PEG 2./ Estane5703.≈ epsilon-CL-2./GAP 2./HTPB 2./F_(2.0}4).By pair correlation function g(r)analyses,hydrogen bonds and vdw are found to be the main interactions between the two *** elasticity and isotropy of PBXs based epsilon-CL-2. can be obviously improved more than pure epsilon-CL-2. *** is not by changing the molecular structures of epsilon-CL-2. for each binder to affect the *** safety and energetic properties of these PBXs are mainly influenced by the thermal capability(C_p^(deg))and density(p)of binders,respectively.

关键词： high energy density material (HEDM), hexanitrohexaazaisowurtzitane (CL-2.), polymer bonded explosives (PBXs), molecular dynamics (MD), compatibility, safety properties, mechanical properties, energetic properties

Study on impurity desorption induced by femtosecond pulse laser based on a stochastic process model

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science China(Technological sciences) 2006年第1期49卷 78-88页

作者： CHI Yinsheng1, LIN Xiaohui1, ZHUANG Ping1 & CHEN Yunfei1,2.1. department of Mechanical engineering, Southeast {2., {3. 2.0096, China 2. Key Laboratory of MEMS of China Educational Ministry, Southeast {2., {3. 2.0096, China department of Mechanical engineering Southeast University Nanjing 210096 China Key Laboratory of MEMS of China Educational Ministry Southeast University Nanjing 210096 China

With the advantages on non-equilibrium heating and desorption induced by electronic transition, the femtosecond pulse laser introduces a new way for solving the problem of impurity pollution adsorbed on a solid thin film in micro-electro-mechanical systems (MEMS). A model based on stochastic processes was established for stimulated desorption induced by the femtosecond pulse laser to interpret the interaction of the opti-cally excited hot electrons with the adsorbed molecules in a metal substrate. Numerical simulation results reveal a time-dependent desorption probability of adsorbed molecules and indicate that how key parameters of femtosecond pulse laser, such as incident laser energy flux, pulse duration, and wavelength of pulse, have a great effect on the desorption probability.

关键词： desorption, femtosecond pulse laser, stochastic process.

EFFECTS OF COMBINED ADDITIONS OF TUNGSTEN AND MOLYBDENUM ON THE CREEP PROPERLIES OFFe_3.l-BASED ALLOYS

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Acta Metallurgica Sinica(English Letters) 2000年第6期13卷 1136-1140页

作者： X.Q. Yu and Y.S. Sun (department of Materials science and {2., Southeast {3., nanjing 2.0096, China) Dep. of Materials and Eng. Southeast Univ. Nanjing 210096 China

Effects of combined additions of tungsten and molybdenum on the creep properties of Fe3.I-based alloys have been investigated. Results show that combined additions of tungsten and molybdenum increase significantly the creep rupture life of the Fe3.l base alloys at high temperature. TEM analysis of the alloys containing tungsten plus molybdenum indicates that both solid-solution strengthening and precipitation harden- ing make the significant increase of creep rupture life.

关键词： Fe3.l creep property tungsten molybde8

Mechanical behavior of a shelter system based on cable-strut structures

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Journal of Zhejiang university-science A(Applied Physics & {2.) 2012年第12期13卷 895-903页

作者： Jian-guo CAI1,2.Ya ZHOU1,Jian FENG1,2.Yi-xiang XU3.(1Key Laboratory of C&PC Structures of Ministry of Education,Southeast university,{2. 2.0096,China) (2.ational Prestress {2. Research Center,Southeast university,{2. 2.0096,China) (3.5} of Civil {2.,Strathclyde university,Glasgow,UK) 1. Key Laboratory of C&PC Structures of Ministry of Education Southeast University Nanjing 210096 China 2. National Prestress engineering Research Center Southeast University Nanjing 210096 China 3. department of Civil {2. Strathclyde University Glasgow UK

A shelter system based on cable-strut structures,consisting of compressive struts and high-tensile elements,is described in this *** deployment of the shelter is achieved by tightening inclined *** cables are used to terminate the *** state of self-stress of the cable-strut structures in the fully deployed configuration is given,and the minimum strut length and the maximum load design of the shelter are *** mechanical behavior of the system was studied under symmetrical and asymmetrical load *** results show that the shelter in the deployed configuration satisfies the ultimate limit and the serviceability limit state ***,the stability of the cable-strut system is investigated,considering the effect of imperfections on the buckling of the *** conclude that the influence of imperfections based on the consistent imperfection mode method is not significant.

关键词： Foldable structures Cable-strut structures Mechanical behavior Self-stress Stability

Surface roughness and removal rate in magnetorheological finishing of a subsurface damage free surface

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Progress in Natural science:Materials International 2005年第6期15卷 538-544页

作者： CHENG Haobo1*, WANG Yingwei2. FENG Zhijing1 and CHENG Kai3.1. State Key Laboratory of Tribiology, Tsinghua university, Beijing 100084, China 2. {2. of Material {2.s, Changchun university of {2. and Technology, Changchun 13.02., China 3. Faculty of Information and engineering Systems, City Campus, Leeds LS1 3.E, UK) State Key Laboratory of Tribiology Tsinghua University Beijing 100084 China department of Material sciences Changchun University of Science and Technology Changchun 130021 China Faculty of Information and engineering Systems City Campus Leeds LS1 3HE UK

Based on computer-controlled optical surfacing, a new technique called magnetorheological finishing (MRF), is presented. The new technique combines the features of conventional loose abrasive machining with a wheel shaped polishing tool. The tool incorporates a host of features and has unprecedented fabricating versatility. The pre-polishing and fine polishing processes can be performed only by adjusting different parameters. The material removal function is studied theoretically and the results of simulation present a Gaussian distribution feature. Based on the established theoretical model, material removal rate experiments involving a parabolic mirror are designed and carried out to determine the effect of controllable parameters on size of the gap between the workpiece and the polishing wheel, rotating speed of the polishing wheel, concentration of volume fraction of non-magnetic particles and polishing time. Further experiments are carried out on the surface microstructure of the workpiece, the final surface roughness with an initial value of 10.98 nm reaches 1.2. nm root mean square (RMS) after 2. min of polishing. The subsurface damage experiment and the atomic force microscopy (AFM) measurement on the polished surface can also verify the feasibility of the MRF technique.

关键词： magnetorheological finishing surface roughness computer controlled optical surfacing subsurface damage removal function.

THEORETICAL ESTIMATION OF GROUNDWATER DISCHARGE AND ASSOCIATED NUTRIENT LOADING TO A LAKE WITH GENTLE SLOPE BOTTOM

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Journal of Hydrodynamics 2007年第1期19卷 30-35页

作者： LI Yong WANG Chao College of environmental science and {2. Hohai University Nanjing 210098 China

A simple estimation model of groundwater discharge and nutrient flux from nearshore unconfined aquifer to lake was studied. It was supposed that the aquifer was permeable isotropic homogeneously and its thickness approximated to the depth of lake. Distribution of the hydraulic gradient and the specific discharge along the transect of the discharge zone were discussed. Results show that the groundwater discharge patterns vary with the inclination angle of lakeshore bottom. For a shallow lake with gentle slope bottom, the rate of discharge of groundwater to lake is not constant across a discharge zone, but the discharge is concentrated in a narrow portion of the littoral zone where the Dupuit assumptions are invalid. The width of the discharge zone is correlative with aquifer thickness and slope of the lake bottom. The distribution functions of hydraulic gradient and groundwater discharge rates accord exponentially with offshore distance.

关键词： shallow lake unconfined aquifer groundwaterdischarge nutrient loading

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 {2. and {2., Hua Zhong {3. of {2. and Technology, Wuhan 43.074, China 2. College of Transportation, Wuhan {3. of Technology, Wuhan 43.063. China 3. department of Mathematics and Physics, Anhui {3. of {2. and Technology, Huainan 2.0}001, China) department of Control science and {2. 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

Predicting neutron star spins from twin kHz QPOs

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science China(Physics,Mechanics & Astronomy) 2010年第S1期53卷 247-248页

作者： SHI ChangSheng department of Astronomy,nanjing {2.,nanjing 2.0093,China College of Material science and Chemical engineering,Hainan {2.,Hainan 5702.8,China 1. department of Astronomy Nanjing University Nanjing 210093 China

We briefly review the proposed relations between the frequencies of twin kilohertz quasi-periodic oscillations(kHz QPOs) and the spin frequencies in neutron star low-mass X-ray binaries(NSLMXBs).To test the validity of the proposed models,we estimate the spin frequencies under these theoretical relations and compare them with the measured *** seems that magnetohydrodynamic(MHD) oscillations are more promising to account for the kHz QPOs.

关键词： win kHz QPOs spin neutron stars LMXBs