数值

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。

An extended hyperbolic mild-slope equation, which can take such terms as wind input, bottom friction and nonlinearity of wave into account, here has been deduced into a parabolic one in the form of a series of governing equations described with complex amplitude. It became a complete wave model when integrated with corresponding physical and imaginary boundaries, and can be solved through the improved Crank-Nicholson or the well known Alternating Direction Implicit difference method, both of which can accelerate the convergent speed , expand limitation of the mathematical method and improve the quality of the solution.

本文基于综合考虑底摩阻、风能输入及非线性影响的推广双曲型缓坡方程，将其进行转换，产生一个演变方程，其复振幅控制方程为抛物线性，并采用ADI差分格式、改进的Crank-Nicholson格式及相应的物理和虚拟边界条件进行求解，以提高数值模拟的适用性、数值计算的稳定性、收敛速度及精度。

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。

This semi-analytical method is accurate and widely used. It overcomes the limitation of the analytical solution such as conformal mapping. The position of cracks can be arbitrary.

这种解析数值相结合求解应力强度因子的方法，充分利用了解析方法精度高和数值方法适用性广的特点，同时又克服了保角变换等解析解的局限，各裂纹位置可以是任意的。

The main works include: In this thesis, we use Finite Difference Time Domain method to study the relationship between diffraction efficiency, angular dispersion and grating constant, to discuss how the grating figure influence the diffraction efficiency, and to research the frequency spectrum characteristic.

主要工作包括：本文分别在垂直入射和自准直入射（光垂直于光栅刻槽面入射）情况下，采用时域有限差分方法，利用商业数值计算软件OptiFDTD对二维闪耀光栅进行了矢量电磁场数值计算，研究了光栅的衍射效率和角色散随光栅常数的变化情况，研究了光栅形状对光栅衍射效率的影响，还讨论了各种光栅的频谱特性。

For the radiation transfer equation, both the spatial domain and the angular domain is discretized, and the finite volume method is used to solve the equation in an explicit way.

把一种新的三维热辐射计算方法应用到高超声速非平衡流场的数值模拟过程中：在非结构网格上对高超声速化学非平衡流场的数值模拟过程中，耦合了辐射输运方程来求解辐射热流。

Based on the former studies, this paper promotes an innovation about this topic using new satellite altimetry data and hydrographic data along with numerical experiments: Firstly, the temporal variation of the deformation of Kuroshio accompanied by the periodically shed anticyclonic eddies from the Kuroshio bend is discovered; Secondly, the major mechanism of the anticyclonic eddy separating from the Kuroshio bend, which is the frontal instability, is brought forward and then proved; Thirdly, the factors with important impact on the periodical variation of the Kuroshio bend and the eddy shedding, which are the strength of the Kuroshio transport and the circulation in the winter SCS, are determined.

本文在前人工作的基础上，利用了最新的卫星遥感资料和海洋调查资料，通过数值模式的数值实验，得到了以下前人没有得到的创新成果：发现在吕宋海峡处黑潮的形变随时间变化，并伴有反气旋涡周期性地从黑潮主体中脱落；提出并证明了吕宋海峡黑潮锋附近的锋面不稳定是反气旋涡从黑潮弯曲中脱落的主要机制；确定了对黑潮弯曲周期性变化以及反气旋涡脱落有重要影响的物理因素是黑潮流量的大小及冬季南海局地环流。

In this dissertation, the following critical theoretical problems on local La-grangian numerical differentiation are studied: explicit formulas, local estimate for the remainder, and the highest order of approximation in the case that the values of the function at these interpolation nodes have perturbationsLagrangian numerical differentiation is a method that the Lagrange interpolation polynomialis differentiated to approximate the derivative, where Tn ={t_0,t_1,......

本文主要研究有关局部Lagrange数值微分法的一些关键性的理论问题：公式的显式表示，余项的渐近估计，以及在插值数据有扰动的情况下，局部Lagrange数值微分法的最大逼近阶。

Some numerical examples are given to show that the numerical method presented is an approximation method with high efficiency and convergence.

数值计算表明本文数值方法是一种高效和收敛的近似方法。

If SUBNAME is specified, it gives the name of a subroutine that compares two list elements and returns an integer less than, equal to, or greater than 0, depending on whether the elements are in ascending sort order, equal, or descending sort order, respectively.

如果指定了SUBNAME，也就是说，指定一个子程序名来比较列表中的两个元素，根据它们的关系是升序排列、相等，还是降序排列，来返回一个小于0的整数值、0，大于0的整数值。

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。