查询词典 difference equation

This paper, considers conservative equation with periodic boundary value problem, and construct a difference scheme, Uses the method of decomposing the singular term from its solution and combining an asymptotic expansion of the equation, proves that the scheme converges uniformly to the solution of differential equation with order one.

研究守恒型奇振动方程的周期边界问题，构造一个差分格式，利用分解解的奇性项的方法，结合问题的渐近展开，证明所构造的差分格式为一阶一致收敛。

By using the solutions of a new auxiliary elliptic equation,a direct algebraic method is proposed to construct the exact solutions of some nonlinear evolution equations.The main difference between this method and previous auxiliary elliptic equation methods is that the balance order becomes smaller after using the new auxiliary elliptic equation.Therefore,the derived algebraic equations are greatly simplified.

利用一个新的辅助椭圆方程将求解非线性发展方程精确解的问题转化为一个代数方程组进行求解，与已有的辅助椭圆方程法的主要不同是，应用这一新的辅助椭圆方程后降低了平衡次数，减少了所得的代数方程组的个数和方程的项数，从而大大地简化了代数方程组的求解。

Spectral element methods for partial differencial equation is introduced in this study from viewpoint of the collocation approximation of Chebyshev polynomial. Wave Equation and its space discretization are deduced. Two time integral methods, central difference method and implicit Newmark method, are introduced, and their stability and applicability are also discussed in some details. The significance of absorbing boundary conditions in spectral element methods for Aeroacoustics is explained, and Clayton-Engquist-Majda absorbing boundary conditions is emphasized and introduced, then the discrete scheme of this boundary conditions is deduced and applied to spectral element methods for wave equation.

本文从Chebyshev多项式逼近理论出发，详细介绍了谱元方法求解偏微分方程的过程；推导了流体中的声波动方程并在空间上对其进行了谱元离散；详细讨论了两种时间积分方法──中心差分法和Newmark方法，分析了它们的稳定性条件，并从理论上对比了两种方法的优缺点和适用范围；将吸收边界条件推广应用于谱元方法求解气动声学问题中，重点介绍了Clayton-Engquist-Majda吸收边界条件的原理和公式，推导了该吸收边界条件的变分形式，并将其引入波动方程的离散形式中。

On the basis of the thermal balance equation,specific inner work equation,cyclic heat absorption equation of a thermal system and the standard coal-consumption calculation formulae of power generation,derived was a general calculation model featuring the influence of lower terminal temperature difference of a heater on the coal consumption of a power plant.

根据热力系统热平衡方程、比内功方程、循环吸热量方程及发电标准煤耗率计算公式，导出了加热器下端差对机组煤耗影响的通用计算模型；并且在考虑到加热器下端差的影响的基础上，改进了以往的建模方法，得到了更为完善的加热器上端差对机组煤耗影响的通用计算模型。

The researches in this paper have offered solutions to initial value problem for ordinary differential equation involving difference of two monotone functions, ordinary differential equation with integral boundary conditions, and first-order impulsive ordinary differential equation with anti-periodic.

本文结果包含了具有两个函数差的常微分方程初值问题(当 Ik=Gk=0，λ1=λ2=0 时)，常微分方程积分边值问题(当 Ik=Gk=0，g=0，λ1=0，λ2=±1时)，一阶脉冲微分方程反周期边值问题(当 g=0，Gk=0，λ2=d=0 时)的相关结果。

By introducing the parameter , construct a new kind of weighted implicit difference scheme for (1+1)-dimension nonlinear Sine-Gordon equation and the generalized nonlinear Sine-Gordon equation respectively. Give out an ADI scheme for (2+1)-dimension nonlinear Sine-Gordon equation.

通过引进参数，分别为（1+1）维的非线性Sine-Gordon方程和广义的非线性Sine-Gordon方程建立了它们的加权隐式差分格式，给出了（2+1）维的非线性Sine-Gordon方程的ADI格式。

Starting with the basic concept about particle transport and the universal form of transport equation, the discuss is concentrated upon the transport equation and the implicit difference scheme under 3-D Cartesian coordinate, as well as the transport equation and the discontinuous finite element scheme under 2-D cylindrical geometry.

从粒子输运的基本概念和输运方程的一般形式入手，重点讨论了三维直角坐标中子输运方程和隐式差分格式，以及二维柱坐标中子输运方程和间断有限元格式。

Therefore,it is necessary to research diffusion equation for suspended sediment because it describes the sediment move process in the water body.The equation is a various coefficients second-order linear partial differential equa-tion,such equation under complex boundary condition is very difficult to get its analytical solution,while its numerical solution relative analytical solution is more easier and has the obvious superiority:simple,the computation convenience.but to get a kind of difference format which is good accuracy and stability is not easy.

泥沙扩散方程实际上是一个变系数的二阶线性偏微分方程，这样的方程在各种复杂边界条件下求解是十分困难的，求它的解析解在数学上存在着难以克服的障碍，无法求出其精确解，因此常用数值方法求它的近似解，相比较而言，数值方法有着明显的优势：即简单灵活、计算方便快捷，但要寻找一种精度高、稳定性好、计算方便的差分格式也并非易事。

In this paper, based on summarizing previous numerical studies on wave transformations, deriving an extended form of mild slope equation, which is taken as the governing equation. The equation simulates wave transformation in offshore area with finite difference.

本文在总结概述前人关于缓坡方程波浪数学模型的基础上，推导出一改进型缓坡方程，并以此为控制方程，采用有限差分方法，模拟近海海域的波浪变形。

For example, a regenerative reheating furnace fluid flow and heat transfer is researched, which has simplified the flow and heat transfer of hot air stove according to its real operating conditions.The fluid flow and heat transfer of a hot air stove are numerically simulated by using finite volume method or finite difference method,which bases on the heat transfer equation,flow equation of the gas and heat balance equation.

根据热风炉的实际运行状况对蓄热式热风炉内的流动换热过程进行了合理的简化，并基于热传导方程、气体流动方程和气体的热平衡方程，建立了蓄热体的非稳态传热模型，在对模型利用有限差分法和有限容积法得到离散方程的基础上，采用C 语言编制了模拟计算程序。

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

If you have any questions, you can contact me anytime.

如果有任何问题，你可以随时联系我。