数值分析

Then the propagation of an arbitrary nonideal optical beam is analyzed. In terms of the moment theorem, the performance of modes of BOR is analyzed from both points of view of geometry optics and diffractive optics. Comparing BOR with the resonators using plane mirror and spherical mirror or using plane mirror and aspherical mirror by finite element method, the design procedure for BOR is gave.

然后以衍射的角谱理论为基础，用矩量定理讨论了任意光束的传播规律，从几何光学和衍射光学的角度完整地分析了二元光学谐振腔的模式特征，用有限元方法数值对二元光学谐振腔、非球面腔和球面腔进行衍射分析，比较了三种腔型的差异，给出了二元光学谐振腔的设计方法。

To improve the simulation accuracy and to make the increment of computation amount the smallest, the quantitative comparison was used to compare the effect of incident direction and difference accuracy on numerical dispersion with the changing of the ratio of horizontal and vertical gird. The results show that the rectangular grid is better than square mesh in suppressing dispersion and can avoid the low computational efficiency caused by high-order difference.

为提高模拟精度，同时又尽可能减少计算量，采用定量分析的方法，对比分析了横纵网格比变化时入射方向和差分精度等因素对数值频散的影响，分析结果表明，矩形网格较之正方形网格能更好地压制频散，同时可以避免高阶差分导致的低计算效率。

MATLAB language is used to develop the computer simulation program by means of the dynamic mathematical model of three - phase induction motors in phase quantities, The program is applied to series asymmetrical resistance starting operation process of three - phase cage - type induction motors in one phases or two phases of the stator circuit.

为了得到起动特性，根据三相异步电动机在相坐标系下的瞬态数学模型，编写计算机仿真程序，通过实例对三相笼型异步电动机的定子电路一相串联电阻以及两相串联电阻时的起动过程进行仿真计算，对仿真结果进行比较分析；用对称分量法分析定子电路一相串联电阻以及两相串联电阻时的不对称系统，初步计算起动电阻的数值，然后通过计算机仿真的调整来较准确地加以确定。

In the aspect of the study of the application of HHT method, This dissertation has done three part of jobs: first, the Elcentro strong ground motion which is in common use in earhtquake engineering is analyzed by HHT method, getting its amplitude-frequency-time distribution and the comparison between the HHT marginal spectrum and Fourier spectrum is also made; second, the typical nonlinear system defined by the Duffing equation is analyzed by HHT method, getting its numerical value's amplitude-frequency-time distribution and the comparison between the HHT marginal spectrum and Fourier spectrum is also made; third, define the stationary degree of non-stationary signals making use of 3-D time-frequency spectrum and marginal spectrum, the stationary degree curve of Elcentro seismic recording is protracted according to its defining formula, the stationary degree curve of Elcentro seismic recording which change with time is protracted according to similiar definition.

在HHT方法的应用研究方面，本文做了三部分的工作：首先，利用HHT方法分析了地震工程中常用的Elcentro非平稳强震记录，得到了该记录的振幅－频率－时间分布特性，并将得到的边际谱与傅立叶谱做了比较；其次，应用HHT方法分析了典型的非线性系统－Duffing方程，得到了该方程数值解的振幅－频率－时间分布特性，并将得到的边际谱与傅立叶谱做了比较；最后，利用三维时频谱与边际谱定义了非平稳信号的平稳度，并依照其定义式绘制了Elcentro地震波记录的平稳度曲线，依照类似与依赖与频率变化的平稳度定义，初步尝试编程绘制了Elcentro地震波随时间变化的平稳度曲线。

Data, Analysis, Results - Our writers always make it a point to include all pertinent numerical data useful in statistical analyses to support hypothesis testing.

数据，分析，结果-我们的作家总是强调要包括所有相关的统计分析有用的数值数据支持假设检验。

Stability of 14 high-cut slopes in Guangdong province is analyzed with typical rock mass structure analysis method and stereographic projection method, and with the numerical simulation method UDEC this paper simulated the excavation and reinforcement courses of the important slopes. Some conclutions and suggestions are based the analysis above.

本文结合广东某省道沿线14个高陡岩石边坡的开挖和支护方案的选择设计，运用常用的岩体结构分析方法和赤平投影方法对边坡的稳定性进行了分析，采用UDEC数值模拟方法对一些重点边坡的开挖支护进行了模拟，得出了以下一些结论： 1、边坡支护形式的选择应遵循"安全绿色、水土保持、恢复自然、环保之路"的设计原则。

In order to study the stability of stratified rock slope in Zhu-Cheng road and its reinforcement method, the potential deformation and slipping mechanism of slope were analyzed using insitu-investigation and stereographic projection analysis method. The numerical calculation model for stratified rock slope was founded with UDEC software. The deformation of rock mass was analyzed in the excavation procedure, and the long-short compound bolt reinforcement structure was proposed according to the deformation failure mode of stratified rock slope.

摘 要：为了研究竹城公路层状岩质边坡的稳定性及防治措施，通过现场调查和赤平投影分析边坡潜在变形滑动机理；利用UDEC软件建立层状边坡数值计算模型，分析开挖过程中岩土体的变形情况；根据变形破坏模式提出层状岩质边坡的长短锚杆交替复合支护结构。

In a word, the use of the pressure test observation, similar simulations, numerical simulation, theoretical analysis, and other means, analyzed systematic to the behavior of superincumbent strata in mining 45 degree coal seams using horizontal section top-coal caving ,and it is for the 45 degree coal seams safe, high-yielding, and high efficiency production of research is of great significance.

综上所述，本文利用现场实测、相似模拟、数值模拟、理论分析等手段，较系统地对45°煤层水平分段综放开采后的上覆岩层移动破坏规律进行了分析，对于45°煤层安全高产高效生产的研究具有重要的意义。

The aerodynamic characteristics of the cuted tip rhombus wing and double-delta wing of middling sweepback angle and aspect ratio about sixty type are investigated by a numerical method based on Eular equations.

采用Euler数值计算方法，对60多种中等后掠角及展弦比的切尖菱形机翼、双三角机翼纵向气动力特性进行了计算、分析和比较，从中筛选出16种切尖菱形机翼、14种双三角机翼进行了全机高速风洞实验研究，给出了机翼的展弦比、前缘后掠角、根梢比及几何扭转变化对全机升力、阻力及俯仰力矩的影响曲线和数据分析，在此基础上提出了用于定量估算两类机翼纵向气动力特性的关系式及修正因子。

All the analytic calculation are verified by Pspice simulation or numeric simulation or experimental measurement , and the two kinds of results are in good agreement, respectively, which show that the proposed symbolic method provides the advantages of both simplicity and accuracy.

本文的所有工作都经过Pspice仿真或数值仿真验证，并在附录中以PWM占空比控制的Boost调节器为例进行了实验验证，所得结果同理论分析非常一致，说明本文提出的闭环系统的符号分析法具有较高的准确性。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。