查询词典 numerical analysis

It is hardly to get and express the solution of the equation of evolution by the analysis, so it used to solve the equation by numerical method.

根据解析的方法求发展方程的解，并且通过已知函数表示出来。

The results of numerical calculation conform the exactness and validity of theoretical analysis and circuit design.

结合理论分析和实验结果，用数值方法进行了对照分析，进一步验证理论分析和实验电路设计的正确性和有效性。

The thecretical analysis is done for the problems of the integral initial values, the accumulated error and the excursive error induced by numerical integrals. It is found that these errors possess characteristics of lower frequencies and they can be treated as the low frequency noise.

针对积分初值、数值积分积累误差和数值积分引入的偏移误差进行了理论分析，得出此类误差均具有低频特性的性质，可作为信号低频噪声进行处理。

Firstly numerical simulations of 2D turbulence flow over trains with wall and without wall are performed so as to investigate mesh, turbulence model, boundary conditions and relative parameters, at the same time, through the analysis characteristics of flow field and aerodynamic forces are acquired for the train under static condition.

首先进行列车有挡风墙和无挡风墙情况下的二维湍流绕流数值计算分析，研究模型网格、湍流模型、边界条件以及有关的参数设置和选取，并获得列车在二维绕流情况下静止时的流场特性与气动力。

In order to solve the problem,starting from the analysis of the simplest plane wave numerical theory,we derived the formula of relative phase velocity and group velocity under the condition of arbitrary high-order finite-difference approximation,and gave the computational method for acquiring the optimum Courant number,and then analyzed the anisotropic effects due to finite difference approximation.

针对此，从最简单的平面波数值理论分析出发，推导了任意高阶有限差分近似条件下相对相速度和相对群速度的计算公式，给出了求解最佳Courant数的计算方法，分析了差分近似造成的各向异性效应。

In this paper,based on the analysis of basic features of ground fissures in Xi an ,the numerical simulation of ground fissures in Xi an is made by using two dimensional finite element method.

本文在分析总结西安地裂缝基本特征的基础上，采用二维有限元法，对西安地裂缝进行了数值模拟。

The model of folded plate flocculator is the test object in this paper. Using the the mechanism and dynamic of coagulation precipitation, vortex of fluid of folded plate flocculator impacting on the coagulation process is studied by test, numerical simulation and theoretical analysis.

论文以折板絮凝池模型为试验对象，结合絮凝机理，采用试验测试、数值模拟及理论分析相结合的方法，对影响絮凝沉淀过程的折板絮凝池中水流涡旋进行了研究。

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。

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。

For a big chunk of credit-card losses; the number of filings (and thus charge-off rates) would be rising again, whether

年美国个人破产法的一个改动使得破产登记急速下降，而后引起了信用卡大规模的亏损。

Eph. 4:23 And that you be renewed in the spirit of your mind

弗四23 而在你们心思的灵里得以更新