微商

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。

In this paper, a high order accuracy difference method is presented for solving unsteady convection diffusion equation by using Implicit Perturbation Finite Difference scheme. Firstly, we use the steady convection diffusion equation, the constant coefficients of this equation are expanded to power series of grid-spacings, then the high-order Perturbation Finite Difference scheme is obtained by determining the coefficients of the power series. Put this scheme on unsteady convection diffusion equations and modified it, the IPFD scheme is constructed.

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。

According to differentiable manifolds theory, the paper discusses tile Legendre transformation of the Pfaffian form, introdues the operator of the Legendre transformation, derives the relation between the Legendre transformation and the partial differentiation and proves three law s.

从微分流形理论出发，讨论了Pfaff形式的勒让德变换；引入了勒让德变换算子；给出了勒让德变换与偏微商的关系；证明了两个定理和一个引理。

In Chapter 5,Use the logarithmic derivative formula of Г function, analysis the characters of X2distributed density function in detail, and the effects of change of the parameter on density curve.

利用Γ函数对数微商公式，较详细地分析了X~2分布密度函数的性质，研究参数n对密度函数曲线的影响。

In Chapter 1, we introduce some theories and methods about the estimation of regression coefficient and do some preparations including some theories in the mean vector, the covariance matrix, the quadratic form of random vector, matrix derivative.

第1章概括介绍线性回归模型回归系数估计的一些理论和方法，并给出均值向量与协方差阵、随机向量的二次型、矩阵微商等预备知识。

In this paper, Some problems about derivations acted on some multilinear polynomials in semiprime rings are discussed. The main result is as follows.

本文主要讨论了半素环的微商共同作用在某些扩张形心上的特殊多线性多项式的问题。

Barles onlyproved the existence of oblique derivative problems by Perron methods i.e.assumethat there is an uppersolution and a lowersolution,then there is a viscosity solution.

Barles也讨论斜微商问题的粘性解的存在性，但他得到的结果也只有在假设上、下解存在情况下有粘性解，这结果不如我们的结果来得直接。

It is proved by using the function approximation theory and martrix theory that for a degenerate elliptic equation of the first class, if the third boundary value condition is satisfied at its nondegenerate boundary and the given derivative values are satisfied at its degenerate boundary, then its solution is existent and unique.

摘 要 运用逼近理论及矩阵理论证明：如果一类退化椭圆型方程在非退化边界上满足第三边界条件，在退化边界上满足给定微商值，那么它的解是存在且唯一的。

It was derived that the modulated reflective spectrum of weak electric field is proportional to the third derivative of the dielectric function with respect to the energy.

分析表明波长调制反射谱的实质，是介电函数对能量的一级微商。

Thermo _ gravimetric analysis is used to determine the components and their contents of a sample of mixture.

白正伟，测定混合物组成及组分含量的热重分析法采用热重-微商热重法确定混合物的组成及各组分的含量。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐