查询词典 implicit difference scheme

Within this context, four specific areas are addressed:(1) By means of finite integration technique, a new kind of the first order partial difference equation is derived from the original disperse transmission line equation of the uniform waveguide's. As it is the kind of one dimension Dirichlet's boundary problem, it is convenient for us to solve this equation from the leapfrog scheme. Because computation is carried out in one dimension, both high calculation efficiency and precision have been obtained in this method. Meanwhile, this method provide us a different selection to simulate the transient response of waveguide with non-simplical, for examples cylinder and elliptic waveguide, and avoid solving the second order equation, or using finite difference time domain to simulate a three dimension problem, sometimes the latter precision is not satisfied with the need, or low efficiency.

在这一研究内容下，主要研究四个方面的问题：(1)在完成金属波导传输线方程时域形式的基础之上，应用有限积分技术，把波导特征模式的色散传输线方程，化简为一组新的一阶偏微分方程组，该边值问题属一维Dirichlet边值问题，从而便于用蛙跳格式求解，由于是在一维中计算，该方法具有很高计算效率和精度，从而避免了以往为得到金属波导中特征模的时域响应特性，须要求解二阶方程，或用时域有限差分方法求解三维问题的方法，对于后者来说，计算有时是不准确的，或是很耗时的例如计算诸如圆波导、椭圆波导等其它复杂形状的波导。

But the finite difference methods require that the computational domain is regular, and usually people construct the finite difference scheme for one dimension and then extend it to two or three dimensions in a dimension by dimension fashion.

有限差分方法要求计算区域比较规则，随着工程问题的复杂化，计算区域也变得复杂，这对数值方法提出了新的挑战。

But the finite difference methods require that computational domain is regular, and usually people construct the difference scheme for one dimension and then extend it to two or three dimensions in a dimension by dimension fashion.

有限差分方法要求计算区域比较规则，而且人们往往是对一维方程构造差分格式，再用分裂方法将其推广到多维。

A combined super compact finite difference scheme is proposed.Numerical characteristics of CSCD is analysed and compared with other symmetric difference schemes.

提出一族组合型超紧致差分格式，对CSCD的数值特性作了分析，并同其他中心型差分格式进行比较。

We introduce the Lax-Wendroff difference method into the calculation of interconnect transmission lines.An efficient Lax-Wendroff difference scheme with second order accuracy is proposed by considering the structure characteristic of telegrapher's equations.

1引言随着信号频率的增加和部件物理尺寸的减小，互连传输线对电路系统的影响越来越明显，该方面的研究在现代高速VLSI设计中具有十分重要的意义。

In APAR simulator system design scheme a new design is used to generate all the sum, azimuth difference and elevation difference channel target echo signal by passing only one channel signal of target through antenna gain multiplication circuit, which simplified the simulator design.

提出了在很短的一帧时间里用匀加速直线运动拟和目标实际运动轨迹的方法，简化了目标回波模拟系统并实现了目标数据的实时模拟。

To investigate the thermal protection effects of a heat sinking vest with phase-change material in high-temperature and high-humidity environment and the feasibility of numerical computation of heat transfer to the vest, based on the analysis of heat and mass transfer characteristic about the accouterments, a thermodynamic model was set up with the enthalpy method. The uniform energy equation was constructed for the whole domain, and the implicit difference equation was used in every node, the distribution of enthalpy was solved by numerical method.

为了研究相变材料降温服在高温高湿条件下的热防护性能和相变材料数值计算方法应用于降温服传热计算的可行性，在分析服装传热传质特点及计算方法的基础上，利用焓值分析法对服装中的相变材料建立传热模型，在整个区域建立统一的能量方程，在区域结点进行离散，并进行隐式求解，得到焓的分布。

To reduce the large numerical dispersion error for the alternating direction implicit finite-difference time-domain method, an isotropic ADI-FDTD method with low numerical dispersion error was presented.

针对交替方向隐式时域有限差分方法数值色散严重的缺点，提出了一种低数值色散的各向同性ADI-FDTD方法。

Based on the second- and fourth-order compact difference formulas for second-order derivatives and the idea of weighted average, two classes of the alternating direction implicit method are proposed for solving two-dimensional wave equation. The methods are of accuracy O (T^2+h^4) and O (T^4+h^4) respectively. Stability conditions are obtained by Fourier analysis method.

基于二阶微商的四阶紧致差商逼近公式及加权平均思想，提出了数值求解二维波动方程的2种精度分别为O(т^2+h^4)和O(т^4+h^4)的交替方向隐式格式，以及与其相匹配的第一个时间层的同阶离散格式，并且通过Foulier方法分析了格式的稳定性。

Basing on the nonatationary linear mild-slope equation developed by Hong Guangwen in 1995, a complete wave model is built considering the bottom friction, nonlinear dispersion relation, and allied reflection and diffraction of several islands. Integrating with corresponding physical and imaginary boundaries, it is solved through Alternating Direction Implicit difference method.

本文以洪广文(1995)推导的非定常线性波缓坡方程为基础，建立考虑底摩阻项，非线性弥散关系，及多岛屿绕射反射作用的缓坡方程求解模式，采用经典的ADI法差分格式，结合物理和虚拟边界条件进行求解。

Pachomius manual labour was organized as an essential part of the monastic life; and since it is a principle of the monks as distinguished from the mendicants, that the body shall be self-supporting, external work of one sort or another has been an inevitable part of the life ever since.

根据圣pachomius体力劳动组织作为一个重要组成部分寺院生活；以来，这是一个原则的和尚，作为有别于乞丐，该机构应自支撑，对外工作的这种或那种已一个必然的一部分，生活至今。

In order to study the effects of parametrical rolling on the ship movement and tilts, in allusion to ship's navigating in regular following waves, the equation of ship rolling motion is transformed into normal Mathieu equation by proper variable replacement when strong parametrical excitation in restoring moment varied according to sine or cosine wave.

为研究参数横摇对船舶运动和倾覆的影响，通过对船在规则波上随浪航行时，恢复力矩中出现的1个以正余弦规律变化的强参数激励项进行适当的变量置换，将船舶的横摇运动方程转换成标准形式的Mathieu方程。