查询词典 difference differential equation

The basic concept in these sections is replacing backward Euler's method by modified backward Eulers's method to approximate the characteristic differential equation and discretizing the convection-diffusion equation at the middle point of the approximate characteristic curve, which will make the convective term get up to second order accuracy.

这三节的基本离散方法是用改进的Euler公式代替向后Euler公式来近似特征微分方程，并且将近似特征线的中点作为离散节点，使得对流项的离散精度提高到二阶，对于扩散项，将其转移到待求时间层进行离散。

The associated Euler-Lagrange equation leads to a nonlinear partial differential equation of second order in the wavelet domain.

通过求解该模型的极小化，推导出其相应的Euler-Lagrange方程为小波域中的二阶非线性偏微分方程。

Some new solutions of an auxiliary ordinary differential equation are obtained, which were neglected by Sirendaoreji etc. in auxiliary equation method.

得到了一个辅助微分方程的一些新解，这些解在Sirendaoreji等的辅助方程方法中没有给出。

By utilizing the auxiliary ordinary differential equation and its solutions, the first kind and second kind of KdV equation with variable coefficients were investigated by means of the extended tanh-function method, and abundant new exact solitary wave solutions were obtained under certain conditions.

利用该方程及其解，采用改进的tanh函数展开法研究了第1类和第2类变系数KdV方程，获得了在一定条件下的若干新精确孤波解。

Based on the theory of mechanical energy conservation,a compressible non-Newton fluid flowing ordinary differential equation on pressure is found by deducing and simplifying the academic formulas with considering the pressure gradient of acceleration,consummating the state equation of foam by using Berthelot second virial coefficient,and logical assumptions.

基于机械能守恒原理，考虑加速度压力梯度项，以Berthelot第二维里系数完善了泡沫流体的状态方程，结合了合理的假设，通过对理论公式推导和化简，得到了非牛顿流体可压缩流动的关于压力的常微分方程。

Many types of optical transmission, and here I step on the weak-guided wave fiber wave equation to study and understand the step-index optical waveguide mode, are second-order differential equations Bessel equation.

光纤传输的种类很多，在这里我只对阶跃型弱导波光纤波动方程进行研究，了解阶跃折射率光纤的波导模式，得到二阶微分方程Bessel方程。

This paper, firstly, after a deep study of image mathematical models, sets up two kinds of image models namely Laplace partial differential equation model and biharmonic equation model and then obtains the eigenvectors of image by the methods of eigenfunction expansion and boundary recurrence.

本文首先较深入地研究了图象的数学描述，提出图象的Laplace偏微分方程和双调和方程两种模型，继而采用特征函数展开法和边界递推法分别求得图象的特征矢量。

In this paper we study the method of interpolation by radial basis functions in H~k(k ≥ 1) and give some error estimates. By means of such interpolation with a special kind of radial basis function, we construct a basis in H~k(k ≥ 1). Combined with the Galerkin method, this theory can be applied to solve boundary value problems for elliptic partial differential equations (such as the third boundary value problem for Poisson equation and the corresponding problem for the biharmonic equation), and some numerical experiments are also given.

本文从求解偏微分方程的角度出发，在被逼近函数u属于一般的Sobolev空间H~k(k≥1)的情形，引入了一种径向基函数插值方法，并建立了相应的误差估计；再利用这种插值性质，从一类特殊径向基函数出发构造Sobolev空间的一组基，针对Poisson方程第三类边值问题和重调和方程类似边值问题，为用无网格算法求解偏微分方程边值问题建立了相应的理论，并通过算例来验证了这一算法。

It is a boundary value problem described by a third-order nonliear differential equation which is called the Blasius equation.

它是一个由三阶非线性微分方程描述的边值问题，其微分方程称为Blasius方程。

In chapter 3, the equation for solving free vibration of tube in tube tall building, which is developed by using equivalent closed tube method, is proved strictly to be the fourth-order Sturm-Liouville differential equation.

第三章严格证明了按等代筒体法推导出来的筒中筒高层结构自由振动方程是四阶Sturm-Liouville微分方程。

There had been a moment during the breakfast meeting, though, after the backslapping and the small talk and when all of us were seated, with Vice President Cheney eating his eggs Benedict impassively and Karl Rove at the far end of the table discreetly checking his BlackBerry, that I witnessed a different side of the man.

那次早餐会期间，在表示过关心和寒暄以后，我们所有人坐了下来，我注意观察了一下，副总统切尼面无表情地吃着班尼迪克蛋（Eggs benedict，源自美国，以英式松饼、火腿、水煮蛋以及荷兰酱组合而成），卡尔。罗夫在餐桌的远端谨慎地经常查看他的黑莓手机，我目睹了他所不为人知的一面。

Talk Undelete failed; someone else may have undeleted the page first.

Talk 无法删除选定的页面或图像（它可能已经被其他人删除了）。