查询词典 difference equation

In system on chaos state, motion trajectory controlled by a equation is sensitive to initial conditions. For example, two trajectory from two close initial values were not very difference at short notice. But the distinct difference will presented consequentially after an enough long time.

混沌状态下的系统，按照某方程运行的轨道敏感地依赖于初始条件，例如从两个邻近的初值出发的两条轨道，在短时间内似乎差距不大，但在足够长的时间以后，必然呈现出显著的差别。

It is shown that in Jameson's algorithm is not an orthogonal stream-lines coordinate system, but a local stream-lines coordinate system instead. Nevetheless, because of the finite-difference discretization in Jameson's scheme is not carried out along the direction of s and n, but along the Cartesian coordinates, the analysis on all terms of the full potential equation in Cartesian coordinates reveals that his scheme does take a back-ward difference along the streamwise exactly at all points in the supersonic flow region.

表明其所采用的坐标系不是真正的正交流线坐标系，而是局部流线坐标系；同时由于Jameson方法并不对s，n进行差分离散，而是在原笛卡尔坐标系下作差分离散，对笛卡尔坐标系下的全位势方程中的各项的分析表明，Jameson方法恰好能做到在超音速点沿真正的流线方向作后差分。

Firstly, based on the wave equation, determining reasonably its initial boundary condition, the paper establishes a computer diagnostic model of oil pumping mechanical well, the damping factor in the model has been reasonably determined, the implicit difference solutionis conducted to the model by changing of step width expression difference solves, and the half analytical solution is explored to the model - fine integral method; and realizes the transformation from dot indicator diagram to indicator diagram of any section.

首先从抽油机井计算机诊断技术的理论基础入手，考虑多级抽油杆连续性，建立了粘滞阻尼波动方程，合理确定模型中的阻尼系数，采用无条件稳定的隐式差分法及半解析方法求解方程，获得抽油杆柱任意断面和抽油泵处的示功图。

The finite difference approximation for this equation is presented.The stability and convergence of the finite difference approximation are analyzed.

并证明了显式格式条件稳定和条件收敛，而隐式格式则是无条件稳定和无条件收敛。

A new scheme for approximating the solution of 2D Maxwell's equations-the high order symplectic scheme is proposed to overcome the shortcoming of the conventional finite difference time domain. The scheme is obtained by discretizing the Maxwell's equations in time domain based on symplectic scheme with high order, and then evaluating the equation in spatial domain with second or fourth order finite difference approximation.

为克服标准时域有限差分方法的缺陷，引入一种新的数值计算方法－高阶辛算法求解Maxwell方程，即在时间上用高阶辛差分格式离散，空间分别采用二阶及四阶精度的差分格式离散。

There are many ways to analysis and computation of Mikthw's two rotations equation,finite difference method is the most one while using the finite difference method,a flood of data need be collected and computed.

而在目前高性能计算机系统中，最广泛使用的并行环境是MPI(Message Pass-ing Interface)，它已成为一种并行程序的标准。

In this paper, a high order accuracy difference method is presented for solving unsteady convection diffusion equation by using Implicit Perturbation Finite Difference scheme.

本文利用摄动差分思想，对定常对流扩散方程中的空间微商系数进行摄动展开，展开幂级数系数通过消去摄动格式修正微分方程的截断误差项求出，由此获得方程的隐式摄动差分格式，将此方法应用于非定常对流扩散方程，并加以修正，得到该方程的修正隐式摄动差分格式。

To price the continuously sampled arithmetic average Asian option, an implicit upwind difference scheme is constructed based on the final boundary value problem of partial differential equation, which is satifiable to the option pricing problem. Then the unique existence and unconditional stability of the difference solution are demonstrated and the error estimate is given under the discrete L2 norm.

研究连续取样的算术平均亚式期权定价问题的差分方法，根据问题所满足的偏微分方程终边值问题，构造出一种隐式的迎风差分格式，论证了差分解的惟一存在性和绝对稳定性，并给出差分解在离散L2范数下的误差估计。

This paper is composed of three chapters, which respectively discusses the following impulsive delay difference equations with discrete variables and continuous variables:In chapter 1, we investigate the oscillation and nonoscillation of equation and some sufficient conditions for oscillation and nonoscillation are obtained. Consequently we extend these results to the difference equations with several delays and with nonlinear impulsive perturbations and with variable delays respectively.

本篇论文由三章组成，分别讨论下面四类具离散变量和连续变量的脉冲差分方程这里p≥0，Q＞0，当n∈N(0)时；p∈C(-1，∞)，R~+，Q∈C

The mathematical models of the dynamics of the mass transfer based on the Nernst-Planck equation were established from which it is found that the different characteristics of the water decomposition between the cation and the anion exchange membranes or resins, is owing to the different potential gradient on the two kind of ion-exchange interfaces, which is further because of the difference between the structure and performance of the different membranes or resins, and is also because of the difference between transfer numbers of cation and anion ions.

根据所建立的传质数学模型方程获知在阴阳膜／树脂表面与水接触的界面层中发生的水解离的差异性，是在于离子交换界面电势梯度的差异，而这种差异又与膜与树脂的结构、性能以及阴阳离子在水溶液中的迁移数的差异有关。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。