查询词典 finite element method

There are direct-acting identification method,jar or bottle identification method,steel tube identification method and hole identification method.Steel tube identification method and hole identification method are better than others method for forensic science,because these two methods have the higher credibility.

目前已经形成的警犬鉴别人体气味的方法有直接鉴别法、罐内或瓶内鉴别法、管式鉴别法和气孔鉴别法，由于管式鉴别法和气孔鉴别法的鉴别结果有较高的可信度，故被法庭科学认为是2种较好的鉴别人体气味的方法。

During the calculation the results got by quintic spline kernel was the best so it was chosen as the proper kernel for the SPH simulation. By comparison of the simulation results got by SPH and finite volume method, it was proved that the buffer cells method proposed in the SPH simulation to implement the Dirichlet boundary conditions was accurate, and this is of great importance for the simulation of flows pass a pipe. At last, the SPH method was improved to simulate the liquid-solid two phase flows and the results show that this method was appropriate for the simulation of flows containing viscous fluid and macroscopic solid components. Now the two methods are both able to predict the continuum flows and rarefied flows severally, but the hybrid program still has some aspects to be improved.

首先用标准算例验证了SPH方法的理论模型和计算程序的准确性；通过比较确定选用五次样条核作为计算低雷诺数下的粘性连续流动时的核函数；采用SPH方法和有限体积法分别对同一管道流动进行了对比计算，证明了本文提出的边界缓冲区方法在实现SPH方法中的流体边界条件时的有效性，解决了SPH方法模拟管道流动时的一个关键问题；巧妙地使用SPH方法对化工分离流动中常见的固液两相流及固液耦合作用进行了模拟尝试，获得了较好的结果；在跨尺度计算方面，目前两个子程序已经能够分别模拟连续的和稀薄的二维管流问题，二者的耦合计算程序还处于调试和优化阶段，各个参数对于计算精度和计算速度的影响规律仍在探索中。

More practical ray tracing methods currently include the wavefront method, the shortest path method, the travel time epenthesis method, the eikonal equation finite difference method, etc.

当前实用性较强的射线追踪方法，包括波前法，最短路径法，走时插值法，程函方程有限差分法等。

This method is variational method, which will be much faster and more efficiency than other method.Firstly we use gauss integral method to disperse the least potential energy of barrette pile group, with the help of vertical settlement finite series and Mindlins equation, we derived vertical load-settlement solution of barrette pile group.

另外，目前有关壁板桩群桩水平承载特性的研究也比较少，因此，为了加深对壁板桩群桩承载特性的理解，本文利用变分法对壁板桩群桩竖直或水平受荷情况下的承载特性进行了初步的研究，通过变分法直接得出荷载位移显式方程，较之以往方法更加快捷。

This thesis is divided into six parts. The first chapter is preface, the current status of research in the inverse problems for parabolic partial differential equations is reported; the second chapter is "regularization methods for numerical differentiation and their applications ", in this chapter we investigate many regularization methods from a viewpoint of regularization theory and algorithm, some applications in the inverse problems for parabolic partial differential equations are given; the third chapter is "spectral regularization methods". Based on Fourier analysis, within the framework of regularization theory, we apply the spectral methods to some ill-posed problems. Many numerical experiments are done in order to show the validity of the methods; the fourth chapter is devoted to wavelet dual least squares method and a revised wavelet method; in the fifth chapter,we combine finite difference method with method of lines and apply it to the backward heat conduction problem in time; in the sixth chapter "identification problems for unknown source ", the essence and the degree of two problems related to source identification are pointed out, at the same time, some numerical methods are reported.

本文分为六个部分，第一章前言简要分析了国内外抛物型偏微分方程反问题的研究现状；第二章数值微分的正则化及其应用从正则化理论和算法的角度出发，考察了许多正则化方法，还给出了数值微分在抛物型偏微分方程反问题的一些应用；第三章谱正则化方法是在Fourier分析的基础上，在一般正则化理论的框架下，给出了这种方法在各种不适定问题中的应用，数值实验表明谱方法是有效的；第四章研究了小波对偶最小二乘方法和改进的小波方法；第五章主要研究了有限差分方法结合线方法在时间反向热传导问题中的应用；第六章是未知源识别问题，主要指出了两类未知源问题的不适定程度和不适定本质，同时报告了一些数值方法。

The material job and main conclusion are as follows:(1)A simple boundary orthogonalization procedure independence grids generation method is put forward on the base of algebraic grid generation method; Data structure and computational model on interface are established aiming at blocks of structured grids.(2) SIMPLE procedure is established in nonorthogonal grids by use of the finite volume method and in-depth discusses on special topic such as boundary condition in nonorthogonal grids, deferred correction method and grads compute on calculational nodes, and so on.

本文完成的具体工作和主要结论如下： 1以代数网格生成方法为基础提出了一种简单的、可独立于网格生成方法之外的边界正交化技术；针对分区结构网格系统建立了分区交界面处的数据结构与计算模型； 2利用有限体积方法在非正交同位网格系统中建立了SIMPLE求解算法，对非正交网格系统中的边界条件、延迟修正技术及计算节点的梯度计算等专题进行了深入讨论。

The Rayleigh method, the Ritz method, the Galerkin method, and the finite difference method are extended to solve the engenvalue problem of the plates.

把瑞雷法、李兹法、伽勒金法和有限差分法推广到了这种板的特征问题的求解。

In this thesis, I summarize the theoretical calculation method, applied scope and notice of siphonic drainage system, and point out the advantage of siphonic drainage system compared with gravitation drainage system. In the archetype experiment study of siphonic drainage tube, I adopt different tube diameter and different structural height to survey the drainage volume and press in different place. I observe various kinds of flow state, and get chief factors which influence hydraulic peculiarity of system as the tube diameter or structural height, and find out the relevance of factor to flux. I apply CFD Fluent software and adopt standard k-ε model and RNG k-ε model, then use finite volume method and second-order upwind scheme to discrete numerical model, while coupling numeration of velocity field and press is based on SIMPLE. In the numerical simulation of curved part of tube, siphonic drainage tube experiment system and multi-outlet siphonic drainage system, I make research on internal velocity and press of system in different project condition by changing the tube diameter of curved part, negative press value in tube export and improving the quantity of water gutter. This thesis first adopts a method of combining archetype experiment and numerical simulation to study the siphonic drainage system, test and verify the validity of experiment and numerical simulation, and makefurther study on system, it solves the problems of limited testing conditions, and has a logical results, it can provide a valid method for optimizing and designing the drainage tube-net system. The conclusion have referring value for study and design of siphonic drainage system.

本文首先对虹吸式排水系统理论计算方法、适用范围以及注意事项做出总结，并分析了虹吸式排水系统的优势；再对虹吸式排水管道进行原型试验研究，采用不同管径不同立管高度，对系统流量、管道压强进行量测，观察了各种工况下的流态，对其水力特性进行研究分析，找出影响水力特性的落差、管径主要因素以及与排水量的关系；进一步应用计算流体力学Fluent软件，采用标准κ-ε模型与RNGκ-ε模型，计算过程应用有限体积法和二阶迎风格式对数值模型进行离散，速度和压力的耦合采用SIMPLE算法，分别对系统弯管段、虹吸排水管道试验系统、多斗虹吸式排水系统进行数值模拟分析，通过改变管段弯头处半径、管段出口负压值、增加雨水斗数对不同工况下系统内部的速度和压力进行研究；本文首次采用结合原型试验与数值模拟相结合的方法，对虹吸式屋面雨水排水系统进行研究，试验与模拟相互验证，并进行拓展，很好地解决了虹吸式屋面雨水排水系统由于试验条件限制问题，结果正确合理，为排水管网系统设计和优化研究提供了有效的方法，对工程设计有较好的参考价值。

There are many methods for computation of the slope and deflection of beams such as the integration method, the finite difference method, the Macaulay's method, the Mohr's 'area-moment' method and so on. They possess mostly the characteristics of complex computing or searching schematics.

有多种方法求梁的位移，如积分法、迭加法、初参数方程法、其轭梁法、有限差分法、奇异函数法和莫尔&面积一力矩&法等等，其大都具有或计算复杂或依赖各种不同的图表等特点。

Usually, distribution networks operate in arborescence mode, so in the simulation of fault analysis the impact of faulty switch element on system reliability is apportioned to failure consequences of adjacent sections that connect to switch, and then an equivalent analytical model considering switch fault is proposed. Thus, not having to conduct the reliability analysis of switch element singly, the impact of switch element fault on system reliability can be calculated. Applying the proposed algorithm in RBTS-BDS6 system, RBTS-BUS4 system and actual medium-voltage distribution network to conduct reliability assessment, the results show that the proposed algorithm is superior in speed and possesses efficiency and engineering practicality.

配电网常具有树状运行特点，在故障解析模拟时，将开关元件故障对系统可靠性的影响分摊到连接开关的相邻分块的故障后果中，进而提出计及开关故障的可靠性等值解析模型，不需单独进行开关元件故障的可靠性分析即可计算其对系统可靠性的影响，应用该算法对RBTS-BUS6和RBTS-BUS4系统及实际中压配电网进行了可靠性评估，结果表明该算法有较明显的速度优势，具有高效性和工程实用性。

Metrorrhagia is also gynaecological problems of common diseases.

崩漏是妇科常见病也是疑难症。

WordFTP gives you the convenience and timesaving you need.

wordftp让您的方便和省时您所需要的。