林木生长与养分动态模型研究Ⅲ.生长方程的假设与前提

结合实例对吴和胡提出的杉木直径、高和蓄积生长方程的基本假设和边界条件进行了详细的说明和论证,并在直径和高生长方程的基础上给出了杉木径高比系数的动态方程．径高比系数随树龄增长而递减的规律表明杉木直径和高的生长速率递减存在不同步现象,产生这一现象的主要原因是林木生长的平面限制效应大于高度限制效应,因此,森林蓄积增长的主要限制因子是树木的直径生长速率．     

日本胴体产肉率方程对我国牛胴体评价的适用性研究

用ＳＡＳ软件对１５２头商品牛的屠宰数据进行统计分析。通过产肉率方程的估测值与实测值的相关及回归分析,初步认为,日本方程对我国晋南牛胴体产率具有一定的预测作用,预测准确率为６６．７８％,但高估了约１０个百分点。但对鲁西牛、杂交牛（西门达尔×南阳牛）、北牛等无预测作用。     

Case- carburization Numerical Modeling and Craft Optimization on Steel Parts of Various Shapes

According to the diffusion equation of carburizing process and its boundary conditionand initial condition, various shapes steel parts are modeled under various case carburize craft parameters, concentration distribution curves have been obtained. Various craft parameters are compared, and carburizing temperature has more influence on carbon concentration distribution. Various shapes steel parts' carbon concentration distribution curves have some difference. According to the carbon concentration distribution curve, craft parameters can be adjusted in order to obtain the best carburizing craft.     

Boundary Element Methods with Overlapping Domain Decomposition for Parabolic Problem

Boundary element method is a numerical method for solving partial differential equations. There are several formulations of boundary element method (BEM) applied to solve a parabolic differential equation.The approach,which employs time- dependent fundamental solution,allows longer time steps in time integration than other approaches,and this can cut down on time for computer implementation with high precision.Domain decomposition method,which decompose the domain that a given problem is to be solved into subdomains,has the advantages of reducing the large problem into smaller ones and reducing the complex problem into simpler ones,and allows parallel computing.An overlapping domain decomposition method is applied combining a boundary element formulation with time-dependent fundamental solution to solve a diffusion equation. Firstly, by domain decomposition, the problem divided into two problems on subdomains, and then the initial-Boundary problems are solved by boundry element method on each subdomain.Some numerical examples are presented to illustrate feasibility and efficiency of the method. The numerical experiments show that the convergence rate of the method is dependent with the overlapping degree of the subdomains.     

Research for Eexperimental System of Differential Isodyne

The .experimental system of differential Isodyne developed by authors is represented. The function and structure characteristic of the rotatable real-time loading device which is set in oil tank , the hydraulic scanning device and the device for synchronous movement of incident beam and Isodyne collector are mainly discussed. The fringe pattern of differential Isodyne in various characteristic directions and planes can be real-timely taken, by using this system. This system is able to apply to stress analyses of local effect .composite materials and structures.     

The Multiple Solutions for a Class of Quasilinear Elliptic Equations

A three critical point theorem is proved. As its applications, Dirichlet problem for a class of quasilinear elliptic equations cf second order is considered.     

Quadrature Methods and Their Extrapolations for Solving Boundary Integral Equations of Steady Navier-Stokes Problems

This paper presents an iteration method of solving non linear boundary integral equations (BIE) of the plane Navier Stokes problem,which each step of the iteration is to solve a linear BIE of nonhomogeneous Stokes problem. Using the quadrature methods of [1],we give a new algorithm with a high order accuracy.The algorithm not only saves work,but also the accuracy can be improved by Richardson extrapolation.     

Damage Constitutive Equation and Experiment of Layered Rock

The microcosmical study on many speciments of sedimentary rock by SEM and petrography theory show that rock is formed of microcrystalline and micropore with all kinds of forms.Therefrom the microstructure model of rock is established.Further the three dimensional nonlinear damage constitutive equation and damage evolution equation of layered rock including respective process of damage evolution,mechanical parameter,effective stresses,and unequal biaxial stress in different rocks are derived.The results of the experiment indicate that the theoretical curve is fairly close to the experimental curve.     

Theoretical Analysis on 13-Bit Lattice Gas Automata Model with Poly-velocity and its Simulation

An 13 bit lattice gas automata model has been investigated from fluid discrete dynamics. By gaining the moment equations from lattice Boltzmann equation and using Chapman Enskog expansion, the fluid dynamics equation and energy equation of 13 bit lattice gas automata model with polyvelocity have been deduced. The validity of the model using for non isothermal fluid dynamics has been proved . Finally, simulation results for non isothermal flow pass plate have been shown