查询词典 method of difference

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。

This research method is independent of Green"s function and variational structure. So it can tackle with the BVP for non self-adjoint and self-adjoint difference equations and overcome the difficulties brought about by the establishment of Green"s function, a study of the sign and the estimate of below and above bounded for Greens function.

本章的研究方法既不依赖于Green函数又不依赖于变分结构，因而能解决非自共轭的差分方程边值问题，且克服了Green函数的建立、其符号的判断及其上下界的估计给研究带来的困难，该方法同样适用于研究自共轭的差分方程边值问题。

The elementary principle of the method is to get out acoustic information from acoustic solid medium firstly through Bragg diffraction ,and then to measure the difference of deflection angular from reference beam of light.

该方法的核心是通过声光布喇格作用，把SAW陀螺效应引起的声速变化信息寄载到布喇格衍射光中，通过检测布喇格衍射角度推算出固体介质的旋转角速度。

Introduced the makeup and analysis procedure of ANSYS software, and the calculating precision difference between tetrahedron element and hexahedron element are discussed, and thorough research are made to the hexahedron mesh method.

介绍了ANSYS程序结构及其分析的基本过程，重点讨论了ANSYS的模型建立和网格划分，初步分析了四面体和六面体单元对计算精度的影响，并对六面体网格划分方法进行了深入的研究。

A detection method based on phase correlation uses a phase difference as the statistical quantum to detect double frequency carrier signal for BPSK DS/SS signals, it has the advantage of the rapid detection and can work well under low SNR condition.

基于相位相关的检测方法把相位差累积量作为检验统计量，通过检测载波二倍频信号来实现对BPSK DS/SS信号的检测，具有检测迅速并能够在低信噪比条件下工作的优点。

On detailed study of the central difference finite volume method proposed by Jameson, discrete formulae of 3-D Euler equations and N-S equations are presented.

详细研究了Jameson的中心差分有限体积法，推导了Euler方程和N-S方程的空间和时间离散公式。

Results 2 parallel detection method chancre hard,flat condyloma and syphilitic rash of patients have significant differences,and the detection rate is a greater difference,PCR results from the higher than RPR.

结果 两种方法平行检测硬下疳、扁平湿疣及梅毒性斑丘疹患者的结果差异有统计学意义，其检出率也有较大的差异，PCR检测所得的结果均比RPR高。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。