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GENERALIZED　BIHARMONIC　OPERATOR　AND　ITS　APPLICATION　TO　THE　BENDING　OF　ELASTIC　THIN　PLATES

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applied Mathematics and mechanics(eng.ish Edition) 1994年第2期15卷 167-174页

作者：俞中直 dept. of eng. mechanics Dalian University of Tech. Dalian

In this paper, δ-function is used to construct the generalized biharmonicoperators, the corresponding quadratic function is presented, and the latter is appliedto the bending of elastic thin plates, The result shows that when the arguments in the variational functional are generalized functions, discontinuity to sone degreeis allowed, and the modified variational principle by using the Lagrange multipliers is merely a special form of the result mentioned above.

关键词： tunction. generalized derivative thin plate variation (mathematies)

Three-dimensional Motion of Multichain-Buoy Mooring System in shallow Water and Survival Conditions

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China Ocean eng.neering 1997年第3期12卷 261-272页

作者： Zhang Ting Sun Mingguang Graduate student, Department of applied mechanics and eng.neering, Zhongshan University,Guangzhou 510275Professor, Department of applied mechanics and eng.neering, Zhongshan University, Guangzhou 510275 dept. of Appl. mechanics and eng. Zhongshan University Guangzhou 510275 China

An eng.neering numerical model for three dimensional motion of multichain-buoy mooring system in shallow water and survival condition is given in this paper. Shooting-aim method is employed for solving the dynamic equations of chain system in order to match the computation of buoy motion. The responses of buoy and chain have been computed for different wind-wave-current directions and different rigidity of chain. The results show that the present numerical model is reasonable.

关键词： survival condition shallow water chain system three-dimensional motion

A Practical Approach of Developing Mathematical Model for All Speed Governors

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Journal of Shanghai Jiaotong university(Science) 2005年第2期10卷 175-181页

作者：王永生 Dennis N.Assanis 张煜盛 Inst. of Energy & Power Huazhong Univ. of Science and Technology Wuhan 430074 China 201 Mail-Box Naval Univ. of Eng. Wuhan 430033 dept. of mechanical eng. & applied mechanics Univ. of Michigan 48109-2125 USA

The paper introduced a special approach for diesel’s all-speed-governor modeling, which, in some cases, could solve the knotty problem frequently met in computer simulation of diesel propulsion system or diesel generating set. Suppose that it is hard to get a control-oriented governor mathematical model when the general approaches, the analytical approach or the experimental approach, are applied, and that an open-loop step response of the diesel eng.ne and its system is available by means of computer simulation, the critical three parameters of a governor mathematical model, the proportional gain K_p, integral time constant K_i, and derivative time constant K_d, can be determined by use of PID tuning method which are widely applied in industrial process control. This paper discussed the train of thought of the approach, precondition, procedure, several modifications of the classical PID model, and some points for attention. A couple of case studies were given to demonstrate the effectiveness of this approach.

关键词： computer simulation mathematical model diesel eng.ne speed governor PID controller

CDS Simulation and Pattern Formation of Phase Separation

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Communications in Nonlinear Science and Numerical Simulation 1998年第4期3卷 233-236页

作者： Zhanaji LIU Men CHeng.Jiong RUAN and Shouji CHeng.(Department of mechanics and eng.neering Science, Fudan University, Shanghai 200433,China)(Department of Mathematics, Fudan University, Shanghai 200433, China) dept. of mechanics and eng. Science Fudan University Shanghai 200433 China Department of Mathematics Fudan University Shanghai 200433 China

Several properties of the generation and evolution of phase separating patterns for binary material studied by CDS model are proposed. The main conclusions are (1) for alloys spinodal decomposition, the conceptions of "macro-pattern" and "micropattern" are posed by "black-and- white graph" and "gray-scale graph" *** find that though the four forms of map f that represent the self-evolution of order parameter in a cell(lattice) are similar to each other in "macro-pattern" , there are evident differences in their micro-pattern, e.g., some different fine netted structures in the blackdomain and the white domain are found by the micro-pattern, so that distinct mechanical and physical behaviors shall be obtained. (2) If the two constitutions of block copolymers are not symmetric (i.e. r ≠ 0.5), a pattern called "grain-strip cross pattern"is discovered,in the 0.43 < r < 0.45.

关键词： lattice gas automata CDS phase separation Pattern formation

λ-PDF AND GEGENBAUER POLYNOMIAL APPROXIMATION FOR DYNAMIC RESPONSE PROBLEMS OF RANDOM STRUCTURES

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Acta Mechanica Sinica 2004年第3期20卷 292-298页

作者：方同冷小磊马晓平孟光 dept.of mechanics Northwestern Polytechnical UniversityXi'an 710072China dept.of mechanics Northwestern Polytechnical UniversityXi'an 710072China College of Mechanical and Power Energy Eng.Shanghai Jiaotong Univ.Shanghai 200030China Institute of UAV Northwestern Polytechnical UniversityXi'an 710072China College of mechanical and Power Energy eng. Shanghai Jiaotong Univ.Shanghai 200030China

A bounded,mono-peak,and symmetrically distributed probability density function, called λ-PDF,together with the Gegenbauer polynomial approximation,is used in dynamic response problems of random *** λ-PDF can reasonably model a variety of random parameters in eng.neering random *** Gegenbauer polynomial approximation can be viewed as a new extension of the weighted residual method into the random *** of them can be easily used by scientists and eng.neers,and applied to a variety of response problems of random *** numerical example shows the effectiveness of the proposed method to study dynamic phenomena in random structures.

关键词： λ-PDF Gegenbauer polynomial dynamic response random structure bounded random variable

Modeling of Mold Filling and Solidification in Lost Foam Casting

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Journal of Materials Science & Technology 2003年第5期19卷 395-397页

作者： Feng.un LI, Houfa SHEN and Baicheng.LIUDepartment of mechanical eng.neering, Tsinghua University, Beijing 100084, China dept. of Mech. eng. Tsinghua Univ. Beijing 100084 China

Based on the characteristics of the lost foam casting (LFC) and the artificial neural network technique, a mathematical model for the simulation of the melt-pattern interface movement during the mold filling of LFC has been proposed and experimentally verified. The simulation results are consistent with the experiments in both the shapes of melt front and filling sequences. According to the calculated interface locations, the fluid flow and the temperature distributions during the mold filling and solidification processes were calculated, and the shrinkage defect of a lost foam ductile iron casting was predicted by considering the mold wall movement in LFC. The simulation method was applied to optimize the casting design of lost foam ductile iron castings. It is shown that the model can be used for the defects prediction and for casting design optimization in the practical LFC production.

关键词： Lost foam casting Numerical simulation Artificial neural network

A Study of the Jet System of the Recovery Concerning Waste Heat of Steam Condensate

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Journal of Systems eng.neering and Electronics 1994年第4期5卷 71-77页

作者： Quo Jinji, Xing Haoxu & Ye Moupingdept. of applied mechanics & eng., Zhongshan University, Guangzhou 510275, ChinaZhang Kangzhi, Wang Guojin & Chen MinjianYinglong Cement Plant, Guangdong, 513000, China dept. of applied mechanics & eng. Zhongshan University Guangzhou 510275 China Yinglong Cement Plant Guangdong 513000 China

This paper presents a frame figure of the recovery system concerning waste heat of steam condensate. When steam phase changes into liquid state in the condenser, the heat equilibium equation, gas state equation, mass flow calculating equation of the jet steam and incondensable gas equation are established. The coupling function between condensate unit and recovery pump of the hot condensate with ejector is studied. The paper sets up the fluid continuity equation, heat equilibium equation and efficiency equation of the ejector and points out the technical key how the prevent hot condensate change into steam phase. When fluid passes from circulation loop through pump to export, the energy equations are obtained here. At last, signal figure of the applied examples are given and settle the techanical questions of the jet system are discussed.

关键词： Steam condensate Heat equilibium equation Recovery heat Jet system

The Application of SCC-DV-X_a Computational Method of Quantum Chemistry in Cement Chemistry

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Journal of Wuhan University of Technology(Materials Science) 2001年第3期16卷 6-11页

作者：王志 dept. of Materials Sci. and eng. Jinan University Shandong 250022 China

It has been explored why quantum chemistry is applied to the research field of cement chemistry. The fundamental theory of SCC-DV-Xα computational method of quantum chemistry is synopsized. The results obtained by computational quantum chemistry method in recent years of valence-bond structures and hydration activity of some cement clinker minerals, mechanical streng.h and stabilization, of some hydrates are summarized and evaluated. Finally the prospects of the future application of quantum chemistry to cement chemistry are depicted.

关键词： quantum chemistry cement calculated results hydratian property

Research on the Electrostatic Torques in the MUM-ESG

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Journal of Shanghai Jiaotong university(Science) 2007年第3期12卷 370-376,382页

作者：郭晋峰糜长军田蔚风金志华 dept. of Instrument Science & eng. Shanghai Jiaotong Univ.

A research on the electrostatic torques in the electrostatically suspended gyroscope (ESG) that uses the mass-unbalance modulation (MUM) scheme (MUM-ESG) to sense the direction of the rotor's spinning axis is presented here. Spherical harmonic functions are used to describe the asphericity of the rotor and the electrodes. Rotational matrix theory in quantum mechanics is utilized to transform the description of the rotor's asphericity from the rotor-fixed frame into the cavity-fixed frame. And the principle of the virtual displacement is applied to find out the electrostatic torques acting on the rotor. Analytical expressions of the electrostatic torques indicate that there are only three kinds of factors need to be considered when looking for the electrostatic torques in the MUM-ESG. The factors are the asphericity of the rotor, the eccentric rotation of the rotor, and the coupling between the rotor's translational displacement and asphericity. An intuitionistic explanation for the electrostatic torque that comes of the rotor's eccentric rotation is presented also. The effects of these conclusions should be tested and verified in the future experiments and applications.

关键词： inertial instruments electrostatically suspended gyroscope (ESG) electrostatic torque