Abstract:A boundary integrate equation and its discrete technique for multi-body contact problem is carried out on basic equations of boundary element method and its fortran program is compiled. Using the method ,the press distribution on the roller plate of the huge excavator with capacity 16 m3 was calculated and a distroy stress analysis of caterpillar of the excavator was carried out.

Abstract:A optimal design with whole structure parameters and its program are carried out. A reasonable model is established. Using the method a optimal design with whole structure parameters by original parameters of American P&H2300xp excavator was calculated. The size,carried out by the method,approximates to the size of P&H2300xp excavator very well.

Abstract:Based on a thermomechanically consistent mechanical model, the constitutive law for a class of complex two-phase materials with locking-in inter-phase residual stress capability is proposed. The developed model contains the current plastic strain in its hereditary integral so that the main features of the above materials subjected to cyclic loading can be well described. The developed model can include both the endochronic constitutive equation and Bower' s empirical formula as special cases. The cyclic plasticity and ratcheting of OFHC copper (single-phase material) and rail steel BS1l(two-phase material)are analyzed and compared with experimental results

Abstract:A new mechanical model on impact system with non-linear element is presented and the practical method for measuring and identifying the parameters is also studied. The results of the experimental analysis and theoretical calculations are satistactory. And we hope to provide more acurate theorecical model for the study and design of impact dampers.

Abstract:The effect of phase angles of commutating voltages on the performance of dc filters is analgzed for the first time and a heurestic method is presented to choose appropriate parameters for swoothing reactors and dc filters.

Abstract:Based on the selaxaticn t echnique, a new approach to solving quadratic programming is presented in this paper. The idea of parametric programming is introduced in the process of solving the problem,and the optimal solution can be obtained through a finite numfer of search iterations. The features of the proposed method are few regurements for the initial values and little computation. It can also be used to solve the parametric quadratic programming. As an example of application, it is applied to solve a real power secure economic dispatch problem in electric power systems,and its calculation results are given.

Abstract:This paper presents the concept of equivalent-unit and the solution method of state probabilities for short-term reliability evaluation for generation systems. The ideas and methods are applied to evaluate short-term reliability of intercommected power systems,and the models of equivalent assistance,which can be conveniently combined with subsystem models,are propesed. The models and algorithm proposed not only solve the difficult problem of "state explosion" , but also improve the calculating accuracy. A numerical example is given to show that the models and algorithm are feasible and effective.

Abstract:The reason of the STM image distortion is analyzed according to the principle of the Scanning Tunneling Microscope (STM). A physical and mathematical model is established and the numeral value solution is obtained by the computer. Finally,the STM distorted image is correctted with a satisfactory result.

Abstract:本文研究了磷钨钼杂多蓝的形成条件及某些光度性质和组成；在0.05～0.20mol/L H2SO、[P]：[W]：[Mo]=3：10：1和 0.4g/L抗坏血酸时形成磷钨钼蓝，其λmax=500nm,ε′=1.3×10∧3L/mol·cm，以Mo（Ⅵ）计0～0.20g/L遵守比尔定律，磷钨钼蓝络合比np·nw：nMo=1：1：2。首次提出测定高速钢中钼的磷钨钼蓝光度法，此法有较高的准确度、重现性、选择性而且较简单快速。

Abstract:The kinetic process of spinodal decomposition in Fe-Cr alloys has been simulated with the aid of the compuler M340. The uphill diffosion of Fe-Cr alloy during spinodal decomposition has been investigated in atomic scale with Monte Carlo method. The computer simulated diagram is in agreement with the experimentally measured one.

Abstract:The precise solution of mathematical model for two-step carburigation has been induced which is under the condition of the third boundary. This solution has been compared with the finite difference technique and its correctness and practicality have been proved.

Abstract:The conditions that the stamping pillow block replaces the founding pillow block is discussed with testing, analyzing, computing and simulative experimenting. In addition,the stamping pillow block s effects on the working internal clearance, the fitting characters and the bearings' durability are analyzed. And finally, the practical parameters of the stamping pillow block are obtained in different working conditions.

Abstract:Experimental results of the basic mechanical properties and failure mode performed on rock salt demonstrate that rock salt is a typical and peculiar soft rock , whose" Young' s modulus/strength(E/S)"ratio is extremely small,and whose failure follows the deformation failure criterion. With these results,this paper develops a theoretic breakdown criterion of hydraulic fracturing in rock salt,which is based on the greatest tension strain failure theory and includes the vertical stress effects. It has been suggested that the critical tension strain should be determined from uniaxial compression tests. This theoretic criterion exceedingly agrees with experimental results and is applicable for every soft rock with small E/S ratio under various stresses.

Abstract:The present paper decribes numerical analytical results of natural convection in a closed cavity partially filled with porous medium by means of Forchheimer-Brinkman model. The effects of heated rate,permeability,height of porous region,heat conduction coefficients and aspect ratio on flow and heat transfar in the cavity are systematically investigated. Velocity and temperature fields in the cavity are given and dependence of average Nu on time is obtained.

Abstract:A processing method for the weight of the object in the fuzzy solving method for the multiojectide optimization are presented. The methods are using different type of membership functions and using the same kind membership function adjusting the parameter. Some corresponding analysis and examples are discussed and the results show that the two methods are very effective.

Abstract:A new scoap-like testability measure SCTM(a signal conflict oriented testability meaure) is presented, which represents not only the difficulty to control and observe the value of a node,but also the probability to cause signal conflict in the process of test generation. A parallel calculation scheme is offered, which speeds up the calculation m/2 times. Here m is the word length of a computer.

Abstract:ABS algorithms new agorithm is introduced with the discussions of the sparse structuere of the projection matrixes and the reorder methods of equations. To apply ABS algorithm on qarallel computer, the parallel ABSalgorithu is also discussed with numerical examples and the time need for the computation.

Abstract:In this paper,we discuss a mathematical mode) for optimization of active power dispatch of large-scale hydro-thermal power systems with cascaded hydropower stations. The following factors are taken into account: the variation of the head in the hydropower stations, water transport delay between cascaded stations etc. Using the decomposition-coordination method of large scale systems, we obtain a three-layer-hierarchical coordination system and a three-layer-hierarchical computational structure. We also discuss the computational methods which are used by each hierarchy. We have taken a test computation and analysing the result of an actual hydrothermal power system. The computational results show that it may obtain a satisfactory economic benefit. The paper provides some research work on the economic scheduling of hydrothermal power systems by the decomposition-coordination method of large-scale systems,multiplier method and a new variable metric method.

Abstract:设Ω是R∧N中单位球，N≥3，本文考虑Dirichlet问题：（*）{-△u=K（x）|u|∧p-1u λu x∈Ωu=0， x∈ЭΩ径向对称正解的存在性。其中0≤K（x）≤C（1 |x|∧α），K（x）≡/0，-N/2<α<0，1

Abstract:A process to develop the valve seat inserts in JL462Q engine is studied. The material is an iron-based alloy without Cr. The results show that the microstructures and properties of the product are as good as those of the product made in Japan. The effects of Mo. Ni. Co. Cu etc. in the alloy are also discussed respectively.

Abstract:This paper discuss the effects of automatic plug mills in small seamless tube mills. Far from traditional ideas,the auther comes rp with mew ideas, which adot the mew process of replacing rolling by piercing,a huge sum of economical interests and great social benefits will be gained.

Abstract:采用自制的喷射装置将Co3O4和T1O2粒子分别喷入锌铝合金（ZA-12）中，研究它们对该合金的机械性能的影响效果。实验结果表明：喷射Co3O4和T1O2粒子能有效地提高合金在室温和100℃下的综合机械性能，特别是高温性能，进一步的观察和分析表明：弥散分布在基体中的氧化物粒子是提高合金机械性能的原因。