查询词典 perturbation method

Secondly, we present the general procedure of our approach and its major characteristics. In the second chapter, we establish the perturbation theory for the nonlinear Schrodinger equation, and study its specific perturbation.

第二章给出了关于非线性薛定谔方程的微扰理论，并通过具体工作来说明我们的基于直接微扰理论的两种不同的思路方法。

Fig.6 Images reconstructed of the semispherical head phantom with and without a homogeneous "skull"approximate positions of perturbations, using a 29 mm diameter plaster rod as a perturbation and using a 16 mm diameter cylinder made of copper sheet as a perturbation.

图6扰动在半球形头模型中的大概位置；扰动目标为直径29 mm的石膏柱；扰动目标为直径16 mm铜管

The comparison of the simulations of the same perturbation in 2D and 3D shows that both are similar before the perturbation arrives at 7 solar radii, and that both have the observed three parts of the classical CMEs. However, the reflecting effect of the adopted boundary conditions at both poles in the 3D simulation has a significant effect on the simulation of more hours, and causes unphysical changes in the polar region, such as the enhancement of density and the change of the magnetic field topology.

从对相同扰动的二维和三维模拟结果的对比来看，在扰动到达7个太阳半径之前，模拟结果相似，都可以模拟出CMEs事件的三部分观测特征，但是三维模拟采用的两极边界条件存在的反射效应，对更长时间的模拟有明显的影响，在两极产生密度增强和磁场位形发生较大变化两个非物理扰动。

In order to give a clear description of the Stark effect of Ba atom, a theoretical study based on the perturbation theory have been carried out, results of which are satisfactory in the weak-electric-field region but unsatisfactory in the strong-electric-field region,indicating the unsuitability of the perturbation theory in this region.

为了更好的解释所观察到的光谱现象，并对Ba原子Stark效应的物理内含进行深入的了解，我们用量子微扰理论对Ba原子在电场下的Stark能级分裂情况进行了理论分析。

The biggest advantage of this mean is that don"t need to computer the perturbation matrix element by using zero level wave function, even don"t need to give out high rank amendatory result using infinite series to sum like the ordinary perturbation theory. Thus, it not only avoids many complicated integral operation, but also obtains high rank amendatory result that it is very difficult to get or cant get.

这种方法最大的优点就是不需要用零级波函数来计算微扰矩阵元，更不需要像普通微扰论那样用无穷级数求和给出高阶修正的结果，这样一来，不仅避免了许多繁复的积分运算，而且求得了普通微扰论很难得到或不可能得到的高阶修正的结果。

Based on the fundamental theory of the cable-prestressed steel truss established in paper [1], the inversive iterative perturbation equations which can be used to determine the stiffeness of elements of the prestressed steel truss with elastic supports are put forward by using the principle of matrix perturbation and introducing the concepts of the combined elements and stiffeness factors.

本文基于文献[1]所建立的拉索式预应力钢桁架基本理论，通过引入组合单元和刚度变化因子，利用矩阵摄动原理建立了以结点竖向位移为约束，以确定弹性支承多次张拉预应力钢桁架各类单元刚度为目标的反演摄动迭代方程。

Some new concepts and algorithms are proposed,such as jobnomial sequence,job perturbation sequence,neighbourhood of job nomial sequence and jobsequence perturbation analysis.These job sequence PA algorithms extend PA techniques aboutcontinuous parameters to discrete parameters and provide some new kinds of tools for solving suchcombination optimization problem.

论文提出了工件序的邻域、摄动序等概念以及对工件序进行摄动分析的思想和算法，将传统的PA算法从连续参数领域推广到离散参数的组合优化领域，为此类组合优化问题增添了新的求解工具。

In order to learn the effect of the random perturbation on imaging quality of the camera during the motion,the process of the dynamic imaging of the camera is analyzed,and the modulation transfer function of the camera is obtained.Then,the influence of the random perturbation,which submits to normal distribution or changes sinusoidally,is studied respectively.

为了描述航天相机运动过程中随机扰动对成像质量的影响，通过分析相机动态成像过程，得到了存在扰动时相机的调制传递函数，并分别讨论了服从高斯分布和具有正弦规律变化的随机扰动对像质的影响。

Based on that, two particular indentities of unitarily invariant metrics are obtained.3 Perturbation analysis of the canonical subspaces: This paper gives the least perturbation bound of the unitary factor on the unitary decomposition.

并利用C-S分解，给出了这类新的酉不变度量的上下界。由此，得到两个特殊的酉不变度量的恒等表达式。3 标准子空间的扰动分析：本文给出了矩阵的酉分解中酉因子的最小扰动界。

This thesis focuses on maximum-power-point-tracking algorithm applying for wind-turbine generator system. The system includes the serve-motor, induction generator, three-phase full bridge rectifier, buck converter and fixed load. This thesis uses traditional Current Perturbation Algorithm as well as Perturbation Stochastic Approximation Algorithm to implemented with Matlab/simlink and hardware to achieve the maximum power tracking.

本文针对风力发电系统提出最大功率追踪法则，整体系统架构包含了伺服马达、感应发电机、三相全桥式整流器、降压直流转换器和固定负载，并由传统电流型扰动观察法合并扰动近似演算法，进行Matlab/simlink 模拟与电路实作设计来完成最大功率追踪。

There are different types of personal loans available.

有许多不同类型的个人贷款优惠。

The above mentioned teaching model of spiral rising can be used to avoid rigidness in teaching.

上述螺旋式上升的教学模式，可以避免教学形成模式後的僵化现象。