查询词典 perturbation theory

This paper mainly consists of three parts:(1) Based on the Reddy's higher-order shear deformation plate theory and general von Kármán-type equations, put forward the governing equations of pre- and post-buckled vibration of several hybrid FGM plate forms which have not been studied adequately, triumphantly applying the perturbation technique combined with Galerkin method into equations solving, and get the comparatively simple result forms with complicated deduction at last;(2) As a new type of materials, piezoelectric fiber reinforced composite actuators were applied to optimal vibration control, interrelated informatons be depicted in this paper;(3) During the investigative cource, some factors not been considered adequently in other researches were discussed fully in the postbuckled vibration analysis, such as the temperature-dependent material coefficients, heat conduction and nonlinear vibration characteristic etc.

本文的研究工作主要包括：(1)基于Reddy高阶剪切变形板理论和广义Kármán型方程，给出了几类现有研究成果较少或没有彻底解决的FGM混合板结构的屈曲前和屈曲后振动特性研究的控制方程，成功将摄动-Galerkin混合法应用于求解过程，并给出了各控制方程相对直观且易于计算的解析解形式；(2)单向压电纤维增强复合材料(Piezoelectric Fiber Reinforced Composite，简称PFRC)是一种新型压电材料，本文将其应用到了结构振动控制研究当中，发现通过压电纤维体积含量的选择可以实现混合板结构的优化振动控制；(3)围绕几种有代表性的FGM混合板结构，讨论其屈曲后的振动特性，在分析中同时考虑热传导，材料物性参数的温度相关性，以及机/热/电荷载耦合效应对非线性振动特性的影响，最后给出了大量数值计算结果。

However, the solutions of the Cauchy problem of the nonlinear hyperbolic system generally develop singularities in finite time even if the initial data are small and smooth.For this reason, solutions must be found in the space of discontinuous functions. Therefore, one can not directly use the classical analytic techniques that predominate in the theory of partial differential equations of other types. Instead, we construct approximate solutions via the singular perturbation methods. By using the compactness of the approximate solutions, we can obtain the existence of the solutions of original system.

然而一般而言，即使是在初值很小且光滑的情况下，非线性双曲型守恒律的Cauchy问题的解在有限时间内也会出现奇异性，为此，我们必须在不连续函数空间中寻找上述问题的解，因此对这类问题的研究，我们也不可能直接利用在其它类型的偏微分方程中占主导地位的解析方法来解决问题，而是通过奇异扰动法构造近似解，由近似解的紧性得到原问题解的存在性。

A kind of one parameter planar singular perturbation equation is studied by the qualitative theory of ordinary differential equations, asymptotic analysis methods, implicit function theorem and fixed point methods.

本文应用微分方程定性理论、渐进分析方法、隐函数定理以及不动点理论的方法研究一类单参数二维奇异摄动系统。

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。

One is the theory of perturbation based on the inverse scattering transformation, which is essential method in searching the solution of soliton, so it have important academic meaning, however, the method is not easily understood and grasped because of its complicated line of thinking.

逆散射法是求孤子解的基本方法，这种微扰论有重要的学术意义，但它的思路迂回曲折，不太容易理解和掌握，因此实用上并不十分方便。

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。

The question studied in the dissertation is supported by National Natural Science Fund(N259675041): Theory and Method of Visual Inverse Perturbation Method.

本文针对上述存在问题，研究机械和工程结构动力优化设计的理论和方法，重点研究逆摄动法求解上述两类反问题。

Based on mathematic operation function of ANSYS parametric design language, reliability calculation of component was realized by programming with APDL according to the perturbation method of reliability theory.

基于ANSYS参数化设计语言的数学运算功能，运用可靠性理论的摄动分析法，利用APDL编程实现零件的可靠度计算，避免了有限元建模、分析和结果的参数化提取等步骤。

The potential energy surfaces of ground state of He—HBr complex have been calculated at several levels of theory, including the single and double excitation coupled-cluster method with noniterative perturbation treatment of triple excitation CCSD.

在用非迭代的三重激发项来校正CCSD的CCSD理论水平下，采用aug-cc- pVQZ基函数对He—HBr的分子间势进行了系统的研究。

In this paper, the current states of research about the basic theory of stationary state perturbation method are firstly reviewed, on base of them, and studied some physics issues mainly about hydrogen atom. The stark effect of the energy level (n = 4) of hydrogen atom is calculated and the stark effect of three dimensional hydrogen atom is discussed by the use of the parabolic coordinates, then the perturbative matrix elements for each energy level are given.

本文首先综述了关于定态微扰论基本理论的研究现状，在此基础上利用定态微扰论对某些物理问题，主要是对氢原子问题展开了研究，计算了氢原子n=4能级的斯塔克效应，并利用抛物线坐标法求解了三维氢原子的斯塔克效应，给出了氢原子斯塔克效应中微扰矩阵元的普遍公式。

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。