查询词典 finite difference approximation

The light distributions in an erythrocyte with the shape of native biconcave,oblate spheroid,or disk sphere under the irradiation of a plane light of 632.8nm were studied with a numerical calculation method of finite difference time domain.

我们用有限时域差分的数值计算方法来研究用632.8nm平面光波照射双凹型，扁球体型或圆盘球体型红细胞后在红细胞内部产生的光分布。

Based on the Boltzmann equation,taking the silicon film as example,the temperature effects on the heat capacity of carrier and lattice,thermal conductivity,relaxation time have been studied with the finite difference method.

基于Boltzmann方程，采用了Chen J K等人建立的自相关模型，考虑了Si薄膜的热容、热导率、弛豫时间等热力学参量随温度非线性变化的影响。

The thesis is organized as follows:In Chapter 1,a new partial differential equation model for Spontaneous Potential log in heterogeneous formations is introduced.At the same time,the existence and uniqueness of weak solution to the problem are proved,and the problem of resistance identification in SP log is studied.Furthermore,a jump condition capturing finite difference scheme is proposed and applied to solve such elliptic interface problems.The effects of various factors on SP response,which include objective layers resistivity,bed thickness,bore-hole diameter,invasion and water-flooded zones and so on,are investigated quantitatively by the proposed method, and satisfactory results are obtained.

具体安排如下：第一章首先建立复杂地层中自然电位测井的偏微分方程数学模型，证明了该边值问题弱解的存在唯一性，在此基础上研究了自然电位测井电阻率识别问题：然后发展了用于求解椭圆交界面问题的间断捕捉有限差分方法，利用该方法定量分析了目的层电阻率、地层厚度、井径、侵入带和水淹层等因素对自然电位测井响应的影响，取得了满意的结果。

In the finite-difference time-domain method, the perfectly matched layer is a kind of high efficient absorbing boundary condition.

在时域有限差分算法中，完全匹配层是一种高效的吸收边界条件。

And the control volume finite difference method based on the boundary fitted curve line coordinate for the coupling model of whole system;(2)introduction of the relative temperature gradient function Sv , which is used to determine the evolution of crystal / melt interface shape, because the shape of the crystal / melt interface during crystal growth is an important factor in determining the crystal quality.

本文采用数值模拟方法，研究了传热对晶体生长的影响，包括以下几个方面：(1)建立了晶体的简化模型，熔体的简化模型和相应的数值计算方法；为了从总体上研究晶体生长的动态特性，首次导出了旋成体曲线座标系的SIMPLEC算法，并成功地应用于晶体生长的整体模拟。

First, the finite difference time domain method with various boundary conditions is introduced.

首先，我们介绍时域有限差分法和相关的边界值条件。

Preserved-amplitude migration ; One-way wave equation ; Fourier finite difference ; Migration operator ; Boundary conditions ; Imaging conditions

保幅偏移；单程波方程；傅里叶有限差分；偏移算子；边界条件；成像条件

Major research work and conclusions are summarized as follows:1 The development of molecular distillation are reviewed in respect of the principle, model research and application; The technical and structure parameters are analyzed with respect to the evaporation rate and separation factor.2 Based on analysis of heat transfer and mass transfer process in WFMD, the discretization forms of bow wave ordinary differential equations and film partial differential equations are obtained with Runge-Kutta method and finite difference method respectively.

主要工作与研究结果如下： 1 综述分子蒸馏技术的应用及其发展现状，从分子蒸馏技术的原理、模型研究及其应用的发展等进行了系统评述；并结合蒸发速率和分离效率这两个评价分子蒸馏效果的重要指标，对刮膜分子蒸馏器工艺参数与结构参数进行了分析与讨论。

Based on time domain Maxwell equations, the basic theory of Finite Difference Time Domain of the cartesian coordinates is introduced in detail.

本文由时域麦克斯韦方程出发，在直角坐标系下介绍了时域有限差分方法的基本原理，分析了电磁波在空间的传播规律及吸收边界的吸收效果。

Numerical simulations of the three dimension viscous flow over the SUBOFF-1 model provided by DARPA and other two models are processed by solving RANS equations withκ-εtwo-equation turbulence model and finite volume method, and with SIMPLEC method for pressure-linked terms, central difference shemes for temporal derivative terms, and second-order upwind schemes for convective and diffusive terms.

本文基于RANS方程，采用κ-ε两方程湍流模型来封闭控制方程，采用有限体积法离散控制方程，对于速度压力关联方程，应用协调一致的SIMPLEC算法求解，变化率项用中心差分，对流扩散项采用二阶迎风格式，分别对DARPA提出的裸艇体SUBOFF-1模型以及另外两种回转体模型进行了数值模拟计算。

We have something to do in the new stage.

在这段崭新的时期中，我们有一些要做的。

The difference between tourism decision-making under uncertainty and risky tourism decision-making is indistinctive.

其中不确定性旅游决策和风险旅游决策的界线比较模糊，两者的区分是相对的。