数值方法

To reduce the large numerical dispersion error for the alternating direction implicit finite-difference time-domain method, an isotropic ADI-FDTD method with low numerical dispersion error was presented.

针对交替方向隐式时域有限差分方法数值色散严重的缺点，提出了一种低数值色散的各向同性ADI-FDTD方法。

Base on the techniques of the Simulation Modeling and analysis, and computer graphics, this paper research the theory and method o...

本文综合运用油藏数值模拟技术、仿真数值分析方法及计算机图形学等科学理论，进行了油气藏开发动态过程仿真技术与方法研究。

The control volume integration was applied to deduce the discrete expressions of the convection-diffusion equations. The staggered grid and SIMPLE algorithm were introduced to deal with coupling between pressure and velocity, and then the numerical computation expressions of such variables as fluid flow velocity and pressure were deduced. Using the backward difference method and incremental theory to discretize the governing equations for fields of chemical reaction, material structure and chemorheology, the numerical computation expressions of variables such as the monomer conversion, average molecular weight and fluid viscosity were constructed.

应用控制容积积分法导出了对流—扩散方程的离散表达式，引入交错网格技术与SIMPLE算法，实现了耦合的压力场与速度场的分离式求解，推导得到了流体的流动速度、压力等物理量的数值计算式；采用向后差分方法和增量方法，实现了化学反应场、材料结构场、化学流变场控制方程的离散，获得了反应转化率、聚合物平均相对分子质量、流体黏度等物理量的数值计算式。

And some computing methods of stochastic differential equation are given.

基于Monte Carlo方法，结合微分方程数值解的方法，采用多种随机过程产生策略和随机模拟方法，对原系统进行了仿真，提出了相应的数值计算格式。

Compared with the conventional model test method and empirical method it is found that the numerical method is more cost-effective and the method is worthy of being advertent and developed.

这一数值计算方法较之传统的实验和经验方法提高了计算分析效率、降低了成本，是一种值得重视和发展的数值计算方法。

Based on the dynamic equation, the transport and acceleration of out-flowing ionospheric ions in the magnetosphere are studied by means of finding the ion distribution function. They include two parts: the study of static ion distribution with analysis and numerical compute; the study of ion acceleration by induced electric feild in the period of dipolarization of taillike geomagnetic lines in the substorm expansion phase with the numerical simulation of the ion distribution function.

本文在磁层中上行离子的加速与传输理论研究领域中，采用动力论方程，用求解离子分布函数的方法来研究问题：(1)用解析求解和数值计算的方法，对上行离子在不同Kp指数条件下磁场位形中的定态分布进行了研究；(2)用数值模拟计算分布函数的方法，对上行离子在亚暴膨胀相磁场向偶极形驰豫过程中受磁尾的感应电场加速进行了研究。

Chapter 4 of this dissertation has carried out a physical simulation study about the processes of formation and laws of evolution of the fan delta in Baimiao gas field. Based on the results of the study about the geological background in this area, this paper has discussed about the sedimentation facies marks for the fan delta in Baimiao gas field, worked out a detailed proposal about the development of physical simulation experiment about the fan delta, and described in detail the general laws and major controlling factors governing the sedimentation processes of the fan delta. A detailed measurement was made about the experimental results, and a systematic comparison was made relative to the prototypic characteristics. Based on the observation and description about the experimental processes and the analyses about the experimental results, this paper has give

在本章中，指出了数值模拟研究的基本特点，给出了扇三角洲形成过程的基本控制方程和数学解法：在此基础上设计和开发了扇三角洲形回成过程的平面二维数值模拟软件，并对计算过程中所遇到的主要问题一计算速度较慢开展研究，对比了以天、旬、月为时间单元进行汁算对沉积结果的影响，研究认为，在流量无突变的情况下，可以适当增长计算的时间步长和适当放松精度要求；根据白庙气田扇三角洲的基本地质特征设计了数值模拟计算的基本条件，以月为单位，计算了扇三角洲四百年的形成过程及演化规律，并以50年为单位输出沉积结果；本章最后还对数值模拟方法及结果进行了讨论。

It effectively solves the problem of contact mechanics between burden granules. The dynamic data structure that is a linked list is built to save and delete the varying data in simulation calculation process. Therefore, the distinct element method simulation model of charging bell-less top blast furnace is established in view of the distinct element method model of blast furnace burden granular.

本文首先对离散单元法的基本原理和数值计算方法进行了系统研究，针对高炉炉料颗粒介质特点，对离散单元法进行了相应改进，建立了高炉炉料颗粒运动的离散单元法基本数学模型，推导出了相应的高炉炉料颗粒离散单元法数值计算基本参数的计算公式，例如阻尼、刚度、时步等，并确定了合理的数值模拟参数值。

The one-dimensional complete hydrodynamic model for border irrigation based on the hybrid numerical method can obviously increase computational stability and convergence, and effectively improve computational precision and efficiency, and provide a good numerical simulation tool for the design of border irrigation system and performance evaluation.

基于混合数值解法的一维畦灌全水动力学数值模拟方法可明显增强数值计算的稳定性和收敛性，有效提高了计算精度和效率，为开展畦灌系统设计与性能评价提供了可靠的数值模拟手段。

In the third chapter, using the methods of nonlinear feedback functions and Lyapunov functions and combining analytical with numerical methods, the nonlinear feedback methods are introduced and the synchronizations of chaos in Hadley system of aerographs and LFRBM system of physics are realized. Some of nonlinear feedback functions are constructed.

第三章在介绍非线性反馈方法原理的基础上，应用非线性控制的基本思想及Lyapunov函数方法，将解析法与数值法相结合，分别对气象学中著名的Hadley环流和物理学中的LFRBM系统进行研究，找到了一类非线性反馈函数，实现了混沌自同步，并利用Mathematica软件进行仿真实验，数值结果说明了该方法的有效性。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。