查询词典 perturbation method

The existence of the radially classical solutions with Dirichlet boundary value in unit ball was investigated. Based on perturbation technique, topological method and comparability theorem, the existence of the radially symmetric solutions for the generalized mean curvature equations with proper presupposition was established.

在单位球内考虑广义平均曲率方程组具有Dirichlet边值条件的径向古典解，运用摄动技巧、拓扑方法及比较原理，在一个适当的条件下，证明了广义平均曲率方程组径向对称解的存在性。

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 order to reduce the influence caused by the controller parameter variations and the plant parameter perturbation, and assurance the tracking performance and the restraint disturbance performance, the improved robust two degree-of-freedom control structure and the linear matrix inequation design method are adopted to design the robust two DOF controller of the servo system in this thesis.

为了降低控制器参数及被控对象参数摄动对系统性能造成的影响，同时，保证系统的跟踪性能和抗扰性能不变。

Design method of the electromechanical actuator controller based on the robust mixed H2/H* control theory is studied, taking advantage of the priority of the linear matrix inequation in solving the problems of the multiobject control, the robust mixed H2/H* control problem of the electromechanical actuator under the condition of parameter perturbation and external disturbance can be transformed to the solving of the linear matrix inequation.

研究了基于鲁棒H_2／H_∞混合控制理论的电动舵机的控制器设计方法，利用线性矩阵不等式在多目标综合控制问题求解方面的优势，将存在参数摄动及外部扰动时的电动舵机的鲁棒H_2／H_∞混合控制问题转化为线性矩阵不等式问西北工业大学博士学位论文题并进行求解。

According to the electric field integral equation of the surface, the recursive solution for the induced current on the slight rough surface is derived using the perturbation expansion of the surface, and the method for computing the interaction field is given.

根据粗糙表面电流积分方程并利用表面微扰展开，得到了微粗糙面表面极化电流的迭代解，给出了耦合电场的计算方法。

Phonon spectrum throughout the Brillouin zone and the interatomic force constants are obtained using the density-functional perturbation theory by the linear response method.

在密度泛函微扰理论的框架下采用线性响应的方法得到了整个声子谱，并分析了原子间力常数。

The exchange energy for the electron transfer process at large internuclear distance may be calculated using either perturbation or variational method.

中文摘要与电子传递相关的远程交换能可用微扰法或变分法计算。

The coulostatic perturbation technology proposed in this paper is a kind of interruptive relaxation method which is characterized by the high measuring speedand will not be influenced by the high resistance media.

本文提出的恒电量微扰技术是一种断电的松弛方法，测量速度快(一般只需几秒钟完成测量)，可以不受高阻介质的影响，特别适宜于像涂装金属这样的高阻体系中应用。

Based on the small steepness parameter, three-layer incompressible, inviscid and irrotational fluid system of arbitrary depth is discussed by using the perturbation method, and a unified theory of nonlinear interfacial-internal wave propagation and the approximate nonlinear evolution equations for interfacial-internal elevations are given on the basis of the rigid upper boundary and the flat impermeable bottom.

基于波陡很小的假设下，利用摄动法，讨论了任意深度的二维不可压缩、无黏性、无旋的三层流体系统，在刚性上边界、平底不可渗透条件下，给出了界面内波传播的统一理论以及描述界面内波波剖面的近似非线性演化方程，最后还讨论了几种特殊情形下的近似非线性演化方程。

In this paper, by using iteration and variation method, the perturbation problem in quantum mechanics will be sloved.

如果满足用微扰方法求解问题的条件，似乎问题已经解决了(见文献[1])。

If you were not , and OS X just booted normally, have no fear.

如果你没有，和OS X刚刚启动通常，没有恐惧。

I only want to preserve our all .

我只想保存好我们的一切