查询词典 numerical analysis

In this article two functional modes of the Fly-back Converter (Continuous Conduct Mode and Discontinuous Conduct Mode) are particularly analyzed, which include their characteristics, applications, the critical pattern of two functional modes is argued, both the exact boundary from the angle of circuit parameters is crystallized, at the same time, basic principle of PFC under the DCM mode is introduced, which settle theoretical basis for the subsequent design; by establishing the mathematic model of the converter, a further investigation of the configuration is made, qualitatively and quantitatively, analyzed to settle exactly theoretical basis for the subsequent emulation and the experimental parameter; from the angle of steady-state analysis, the transfer function of the system is deduced to establish dynamic small-signal state equation, emulating the system with the help of matlab, then according to the simulation result and the theory of PFC revise the system, lastly, we adopt the project which add a zero-pole compensator to the voltage loop, by this way, a satisfied system performance is gained and the PFC scheme is ensured successfully; finally, based on the previously-done work, we combining with the situation of specific design requirement, acquired the numerical value of each unit devices in this converter

详细分析了反激式变换器的两种工作状态，连续模式(Continuous Conduct Mode ，简称CCM)和断续模式(Discontinuous Conduct Mode，简称DCM)以及各自的特点、应用场合，论证了两种工作状态的临界模式，从电路参数的角度明确了二者的界限，同时还介绍了DCM模式下PFC的基本原理，为后面的设计奠定理论基础；通过对整个变换器系统建立准确的数学模型，对此变换器的电路结构做了进一步的研究，定性、定量地分析了变换器各部分的工作状态，为仿真和实验参数的确定以及电路参数的优化提供理论依据；从稳态分析的角度，为系统建立了动态小信号状态方程并推导出系统的传递函数，利用matlab对系统进行仿真，进而根据仿真结果以及PFC的相关理论对系统进行校正，采用在电压环加入零点—极点补偿器的设计方案，得到了满意的系统特性并且保证了PFC的顺利实现；最后，在前面所做工作的基础上，结合设计要求计算出此变换器系统中每个元器件的数值，利用Pspice对其进行了仿真、优化，然后根据仿真结果搭建了硬件电路。

The basis function of the coinjection of Nitrogen and steam is increasing the displacement volume and supply the displacement energy on the basis of Nitrogen, the result of the numerical simulation showed that, after the coinjection of Nitrogen and steam (the optional aqueous Nitrogen ratio was 1: 20～1: 50), the theamal readius increased from 30m to 55m more or less, the recovery ratio increased by 5～10％. The production effect of the high cycles steam stimulation will be improved and the pattern infill will be avoided and the economic results will be improved. 4. The poor result of steamflood is another problem. On the basis of the analysis of the foamer mechanism in the propayation, movement and stabilization, this paper showed that the main meachanism of the increasing recovery of the Nitrogen foam and steamflood was the increasing displacement factor and oil displacement efficiency.

三针对蒸汽吞吐加热半径有限（一般30m左右）而蒸汽吞吐轮次已高达5轮以上的具体情况，将氮气与蒸汽混合（套管环空中注氮气，油管中注蒸汽）进行吞吐可增加加热半径1～2倍以上；在对原油流变性研究基础上，对氮气蒸汽原油体系状态进行了分析，指出了氮气在油藏中基本上是以气相方式存在；热氮混合吞吐的基本作用为扩大波及体积和提供驱油能量；在此基础上所进行的热氮混注数值模拟研究表明：蒸汽中加入氮气后（最佳汽氮比为1：20～1：50），加热半径从30m增至55m左右，采收率可提高5～10％以上，大大改善了高轮次蒸汽吞吐的生产效果，可避免大规模井网加密，提高了经济效益。

After compared with other several numerical analysis methods, Fourier series fitting method is applied to calculate the parameters of motion of the mechanism.

最后通过对几种数值计算方法在计算机上进行实际计算比较，确定采用基于最小二乘原则的Fourier级数拟合方法计算出机构的运动参数。

In Chapter 4, we consider more complex fractional nonlinear differential equation,also using the high order approximation presented by Lubich to construct correspond-ing numerical scheme and giving the error analysis of the algorithms.

在第四章中，进一步的考虑更复杂的非线性分数阶常微分方程，同样利用的是Lubich提出分数阶导数的高阶近似，构造相应的数值格式，并给出这一算法的误差分析，即相容性，收敛性和稳定性的证明。

Finally, based on the fundamental solutions of Biots consolidation of transversely isotropic saturated multi-layered soils, the Fredholm integral equation of second kind for the interaction between transversely isotropic saturated multi-layered soils and rectangular piles is established, the relevant numerical analysis is also carried out.

最后，基于横观各向同性层状饱和地基Biot固结问题的基本解答，建立了横观各向同性层状饱和地基与方形单桩、群桩共同作用问题的第二类Fredholm积分方程，并进行了数值分析与计算；通过将矩形刚性基础基底划分成若干个大小相等的矩形网格，用矩形均布荷载表示网格的基底反力，并利用已获得的横观各向同性层状饱和地基Biot固结问题的基本解来求解每个矩形网格的柔度系数，然后根据刚性基础与层状饱和地基的接触条件和其本身的静力平衡条件，求解分析了横观各向同性层状饱和地基与刚性矩形板的共同作用问题。

On the basis of theoretical analysis of digital holography, the preliminary study carries out through computer simulation and experiments. The main work is as follows:Firstly, on the basis of off-axis Fresnel diffraction, the principles of optical holography and digital holography are introduced. Besides, the theories such as recording digital hologram, numerical reconstruction and the related digital image processing methods are analyzed.

本论文从理论分析、计算机仿真和实验三个方面对数字全息技术进行了初步的研究，主要完成了以下工作：首先，介绍了传统的光学全息术和数字全息技术的基本原理，以离轴菲涅耳全息为例对数字全息的记录条件、数值重现算法、以及相关的数字图像处理方法进行了详尽的理论分析。

The rigorous full-wave analysis of monolithic microwave integrated circuits and microstrip antennas has been made possible due to large increases in computing power and the development of a number of numerical techniques.

随着计算能力的提高和数值方法的发展，单片微波集成电路和微带天线的严格全波分析有了可能。

Therefore, a new and functional numerical method and quantitative analysis method are provided.

因此对该类问题的研究提供了新的实用的数值解法和数值分析方法。

The numerical results of ultimate uplift resistance coefficient obtained by using two typical normally consolidated clay, gault and kaolin clay agree well with limit analysis accurate solution.

重粘土和高岭土两组典型正常固结土样所得的极限承载力系数与极限分析给出的精确解一致。

Gauss numerical integral method is used in the precise elasto-plastic analysis of structures andthus the development of plastic deformation along the section and the length can be considered.

并通过与实体模型计算效率和计算精度的比较，说明了本文的分析力学模型、分析方法和分析程序的正确性、精确性和有效性。

The production moved off-Broadway to New York City, where she won the Joseph E. Calloway award for her performance, and was profiled in American Theater Magazine as one of ten young theater artists to watch.

生产提出过百老汇的新的纽约市，在那里她赢得了约瑟夫calloway奖，她的表现，并于异型在美国的战区杂志之一， 10战区的青年艺术家观赏。

It's a risk tradeoff, and I believe that adding test support code usually wins.

这是一个风险的权衡，我相信添加测试代码通常会占上风。