数值的

The SEM can get a global diagonal mass matrix, which leads to a very simple explicit time difference scheme and high efficiency. Numerical simulation in the transversely isotropic medium are shown and the results approved that the SEM is a effective method for seismic wave modeling.

文中阐述了基于Legendre多项式的谱元法的理论和推导过程，该方法可以形成全局对角质量矩阵，在时间域使用显式的差分算法，提高运算效率，最后通过横向各向同性介质的数值计算，模拟结果表明该方法是一种有效的数值模拟方法。

The outflow fields of a simplified fastback car were studied with numerical methods of different turbulence models and diflerent discretization scheme s with the CFD code STARCD.

以简化的直背式轿车模型为研究对象，以商用计算流体力学软件STAR-CD为工具，应用不同的湍流模型和离散格式对轿车外流场进行了数值模拟，通过与试验结果的对比，研究了湍流模型和离散格式对直背式轿车外流场数值计算精度的影响，同时对SIMPLE算法及其两种修正方法PISO和SIMPISO算法的计算精度进行了比较。

The computation results agree with the experiment results very well. The muzzle flow field of an artillery with a muzzle brake is also simulated. The main characteristics and the mutual relations of shock waves in the muzzle flow field are obtained by the simulation. On the basis of the simulation results, the influences of the brake holes on the muzzle brake capabilities are analyzed.

对某口径火炮带有制退器的膛口流场进行了数值模拟，其结果反映了制退器内外流场的主要特征和冲击波波系之间的相互作用，在数值模拟的基础上分析了3排侧孔对制退器性能的影响。

By using unstructured dynamic grid based on local remeshing method, the variation of grid caused by projectile movement was analyzed. Numerical computation results of gun muzzle flow field which arranged in time was obtained. The creation process of the complex flow field of gun muzzle was described. The numerical simulation of flow field including moving projectile was achieved.

采用基于局部网格重构法的非结构动网格技术处理弹丸运动造成的网格变化，给出一系列按时间顺序排列的膛口流场数值计算结果，描述了复杂的膛口流场形成发展过程，实现了含运动弹丸的膛口流场的数值模拟。

The diffraction distributions of Gaussian beam limited by the circular apertures with different sizes in scanning objectives focal plane were studied, and then the effective spot radius in focal plane was calculated using second moment and compared with the ideal one. The influence of apertures with different sizes on resolution was analyzed.

在不同孔径圆孔的限制下，对扫描物镜焦面上的衍射光场分布进行数值计算，并利用二阶矩统计的方法对焦面上的等效光斑半径进行数值计算，将其与不受限时的理想情况进行对比，分析孔径尺度对激光束扫描系统分辨率的影响。

According to the character of outer shape of modem buses, the numerical calculations are performed from the simplest shape-cuboid by using ANSYS/FLOTRAN software. First, the foreside of the cuboid is modified step by step in 17 models (this is equal to the process of modification to the foreside of a bus).

在本文中，应用ANSYS／FLOFAN软件，根据现代客车外形的特点，从最简单的长方体开始进行数值模拟计算，首先对长方体的前部进行逐步改造(相当于对一个客车头部进行改造的过程)，这一步骤包括了17个模型；然后再对其尾部进行变化，以模拟客车后车体形状对空气阻力系数的影响，该步骤包括9个模型：最后给出两种现代客车的数值模拟结果。

The evolution of frontal rainbands happening during the frontogenesis induced by deformation field is investigated through the numerical cloud model. Besides, in order to get insight from the results of numerical simulations, the semigeostrophic frontogenesis model is used to investigate the effect of diabatic heating on the frontogenesis and the analytical method of WKBJ is used to study the influence of large-scale deformation field and frontal circulation on the development of symmetric disturbance happened in the frontal zone.

为了加深对数值模拟结果的理解，还利用半地转模式对非绝热加热影响锋生的过程进行了讨论，通过WKBJ方法讨论了变形场锋生条件下对称扰动的发展，从中可以了解大尺度变形场和锋生环流对中尺度扰动的作用，这方面的工作可以对前面非静力数值模拟结果的理解提供帮助。

Similarly, numerical experiments are performed to demonstrate the efficiency and efficacy of the geodesic distance based MFS for piecewise smooth domain. In addition, the effect of the number of collocation points and the stability with respect to the anisotropy are discussed.In Appendix A.

在后面同样给出了数值例子以说明方法的优越性，不同的是这里考察了分片光滑的几何区域，并加上了配置点数目对数值结果的影响以及该方法对各向异性的稳定性分析。

The GKS stability theorem for one-dimensional model of hyperbolic initial and boundary value problem, Trefethen's explanation and extension based on the concept of group velocity are generalized firstly. Another possible high-frequency instability mechanism in numerical realization of MTF is pointed out based on his explanation and extension, namely, coupling effect of outgoing harmonic wave along one direction and node motion in the other directions can reverse the energy propagation in multi-dimensional discrete grids.

本文概述了—维双曲型偏微分方程组初边值问题数值稳定性的GKS定理及Trefethen基于群速度概念对这一定理的解释和推广；并应用Trefethen的解释和推广指出了MTF在数值实现中可能出现的另一种高频失稳机制，即在多维离散网格中，沿某一空间方向的外行简谐波，由于与其他空间方向节点运动的耦合效应可以使能量传播方向反向。

The relation between the center of time gravity of the ultrashort pulse and the carrier phase was studied by using three kinds of pulses,named Gauss,Hyperbolic Secant and Lorentz pulses.The analytical expressions of the relation between them was deduced.

以Gauss、Hyperbolic Secant、Lorentz三种脉冲为例，利用理论推导和数值模拟的方法研究了载波相位对超短脉冲时间重心的影响，并给出了三种脉冲的时间重心与载波相位的解析表达式和数值模拟的图形。

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。