查询词典 calculus of finite differences

Objective: The purpose of this study is to develop a systemic and geometrical detailed three-dimensional finite element model based on the healthy human foot and investigate the foot inner biomechanical properties during balanced standing using a static finite element analysis.

目的：建立一个基于健康人体的、系统的、具有高度几何相似性的足部三维有限元模型，并用此模型静态地分析人体双足站立相时的足部内部的生物力学特性，量化足部内部的应力/应变状况、足部内侧纵弓变化等。

Modify the model by FreeForm software and dissecte the model of haunch bone; import the 3D visible model of haunch bone into Ansys8.0 software. Add mechanics parameter to the haunch bone model, construct 3D finite element model of acetabulum. 2、On the base of common fracture line of acetabular posterior wall fracture in clinical cases, split the acetabular 3D finite element model according to 1/3, 2/3, 3/3 areas fractures of posterior wall after simplify setting, obtain four types of acetabular posterior wall fracture model(including normal condition of acetabulum).

按髋臼骨折Letournel分类标准并根据临床髋臼后壁骨折病例常见骨折线位置，进行简化设定，依次按后壁1／3，2／3，3／3面积骨折将髋臼三维有限元模型后壁进行拆分，获得三种髋臼后壁骨折状态的有限元模型；再模拟双足直立位对髋骨约束设定，分别对后壁正常及不同面积骨折状态模型进行加载，获取各模型应力分布图并记录臼顶负重区、髋臼前壁和剩余后壁在不同后壁骨折状态下应力分布大小及改变。

Chapter 4 puts up the basic theory of non-linear finite element calculation methods and deduces calculation iterative formula and relevant accelerating iterative format. In the calculation of non-linear finite element, yielding element calculation is a difficult problem,"fictitious elastic stress" methods propounded in this paper puts the axe in the helve.

第四章提出了非线性随机有限元法的基本理论，并推导了计算迭代公式，为加快计算速度，提出了相应的加速迭代格式，对于基于非线性随机有限元的可靠度计算中，屈服单元的计算方法是一个难题，本文提出了"虚拟弹性应力"法，较好的解决这个难点。

The fatigue is analyzed for the SENT specimen of TA6V titanium alloy at different stress ratio and on different stress level by the general finite element analysis software ANSYS. The dangerous fatigue location is predicted by the nodal stress Y-direction of the hemicycle notch for TA6V titanium alloy SENT specimen. Based on the local stress-strain method and the material S-N graph, the nominal stress-strain of the specimen is converted to the local stress-strain of the dangerous location by the elastic and plastic finite element analysis, thus the fatigue life is estimated by Miner fatigue damage accumulation theory and compared with the fatigue test of small crack growth.

借助大型通用有限元分析软件ANSYS对TA6V钛合金SENT试样在不同应力比和不同应力水平下进行疲劳分析，根据SENT试样缺口处的应力状态分布预测疲劳危险部位，采用局部应力应变法，结合材料循环的S-N曲线，通过弹塑性有限元法将构件上的名义应力谱转换成危险部位的局部应力应变谱，从而根据危险部位的局部应力应变历程采用Miner累积损伤理论对构件的疲劳寿命进行估算，并与疲劳小裂纹试验数据进行比较分析。

In chapter two, the basic knowledges of finite state automata and finite homogeneous Markov chain are introduce.

第二章，介绍有限状态自动机、有限齐次马尔可夫链及随机系统的基础知识。

By using non-linear finite element theory, a non-linear finite element model for hydroforming for rear axle housing is established.

利用非线性有限元理论方法，建立了后桥壳液压胀形有限元模型。

In the fourth section, we stress on the study of the finite type rotation hypersurfaces, and obtain the classification of two and three dimensional spherical and hyperbolic rotation surfaces of finite type. It is proved that the parabolic rotation hypersurfaces are minimal or maximal.

第四节着重对有限型旋转超曲面进行了研究，得到二维和三维球型、双曲型有限型旋转曲面的分类结果，证明了有限型抛物型旋转超曲面是极小或极大超曲面。

In this paper, a high order accuracy difference method is presented for solving unsteady convection diffusion equation by using Implicit Perturbation Finite Difference scheme. Firstly, we use the steady convection diffusion equation, the constant coefficients of this equation are expanded to power series of grid-spacings, then the high-order Perturbation Finite Difference scheme is obtained by determining the coefficients of the power series. Put this scheme on unsteady convection diffusion equations and modified it, the IPFD scheme is constructed.

本文利用摄动差分思想，对定常对流扩散方程中的空间微商系数进行摄动展开，展开幂级数系数通过消去摄动格式修正微分方程的截断误差项求出，由此获得方程的隐式摄动差分格式，将此方法应用于非定常对流扩散方程，并加以修正，得到该方程的修正隐式摄动差分格式。

With an additional terminal cost in the standard finite horizon objective functional and a terminal inequality constraint,the prediction is expanding quasi to infinity but the control profile to be determined by on-line optimization is only of finite horizon.

开环优化问题含有附加的终端代价项和终端约束条件，这样预测时域延伸至准无限，而需在线优化获得的控制函数仅为有限时域。

By extending the concepts of supremum and infimum in real space to the casein any finite-dimensional Euclidean space a weak supremum set and infimumset theory with respect to cones for the set in finite-dimensional Euclideanspace is developed,and several similar properties to the set in real space are ob-tained,with the concepts of this weak supremumset,w-D-conjugate maps and w-D-subdifferentials theory for the point-to-setmap are developed,and its several properties and its relationships with weakefficient solutions of the multiobjective programming are studied.

推广实空间中上、下确界的概念至任意有限维欧氏空间，建立了有限维欧氏空间中集合的锥弱上、下确界集理论，得到了与实空间中十分相似的性质。借助于这一理论，应用上、下确界的概念，给出了点集映象的w-D-共轭映象及w-D-次微分理论，并研究了它们的若干特性及其与弱有效解之间的关系，此外还讨论了弱鞍点问题。

World War II: Battle of Saipan - Americans take Saipan.

1944年的今天，美国在塞班战役中拿下塞班岛。

When the scorner, the rejecter of truth, has become presumptuous; when the routine of work in the various money-making lines is carried on without regard to principle; when the student is eagerly seeking knowledge of everything but his Bible, Christ comes as a thief.{DA 635.3

当讥诮和拒绝真理的人，到了任意妄为时，当追求财利者罔顾按道义经营谋利时，当学人正在兢兢业业地研究各种知识，而单把圣经丢在一边时，基督要像贼一样来临。