波动方程

Its discretization is based on spectral elements in space and central differences method in time. The numerical result, shows that this approximation has spectral accuracy in space and up to second-order in time.

该解法引入一阶Clayton-Engquist-Majda吸收边界条件，在空间上利用谱元方法，在时间上利用中心差分的积分方法得到波动方程的离散形式，并给出具体算例进行了验证。

Various forms of wave equations, definitions of wave number and frequency, derivations of phase speed and group velocity, and a quick discussion on dispersion relationships.

各种形式的波动方程，波数和频率的定义，相速度和群速度的引入，以及一个关於色散关系的小讨论。

Week 6 Standing wave equation, quantitative analysis of standing wave quality, source of light and interference source of light.

第6周 驻波的波动方程；驻波特性定量分析；光源和相干光源。

To analyze the pseudo phenomena caused by migration velocity error, the paper firstly studied the depth error between post-stack migration and prestack migration caused by same velocity error, and found the depth error was only relative to velocity error and had no direct matter with methods of depth migration (post-stack migration or prestack migration). Then the paper did numerical simulation of a complex lenticular body model with wave-equation modeling and migration, and found that the velocity error could not only induce depth error, but also could change the modality of construction and the event of subjacent layers. Furthermore, it could change the frequency of reflective event. They are the pseudo phenomena caused by migration.

从分析偏移速度误差带来的各种假象出发，本文首先对比分析了速度误差对叠后深度偏移和叠前深度偏移的影响，发现偏移剖面的深度误差仅与速度模型的误差有关系，与具体的偏移方法没有直接的关系；然后对一个复杂的透镜体模型进行了波动方程叠后正演和偏移计算，详细地讨论了不同的速度误差带来的各种假象，发现速度误差不仅会带来深度误差，而且会造成构造体的形态变化，下覆地层同向轴的扭曲，还可能引起地层同向轴的频率发生变化，给资料解释带来一定的假象。

The imaging results of salt flanks and subsalt structures by applying reverse imaging are better than one-way wave-equation migration.

实例分析表明，逆时偏移对盐体侧翼及盐下构造的成像效果要优于单程波波动方程偏移。

In this paper, inverse scattering series method is based on wave equation and Born series, multiples are predicted and removed by constructing a subseries corresponding to surface-related multiples. This method does not need any subsurface information and is suitable for different kinds of complex structures.

本文研究的逆散射级数法以波动方程和Born级数为基础，构造一个与自由表面多次波相关的子序列来预测并消除多次波，该方法不需要知道地下的速度结构信息，适用于各种复杂的地下情况。

For the wave equation on the torus, we look for some special global solutions-periodic solutions.

接下来我们对二维环面上的波动方程寻找一些特殊的整体解：周期解。

Beginning with wave equation, the paper has deduced the propagation of gauss pulses in single mode fiber and fiber grating transmission compensation. The characteristics of cascaded phase-shift gratings are discussed by numerical simulations of coupled-mode theory and T-matrix method. The experimental works and measurement results are shown in this paper. On the other hand, we have introduced the basic theory of EDFA and figured out the characteristics for EDFA at different conditions by numerical simulation. Some experimental results for EDFA are also presented here. In this article, you can find the influence on Optical Fiber Amplifier by Gain Tilt, especially, the negative effect on CSO in CATV transmission system.

论文首先从波动方程入手，对高斯脉冲在单模光纤中的传播演化及光纤光栅透射补偿进行了详细的研究；较系统地介绍了光纤光栅的耦合模理论，并将传输矩阵计算法用于计算级连相移光纤光栅的光学特性；重点介绍了作者在光纤光栅刻制及特性测量方面所做的一些实验研究工作；较系统介绍了EDFA的基本理论，计算出各种条件下EDFA的光学特性，并进行了一些实验研究；综合分析光纤放大器对光纤传输系统的影响，特别分析了光纤放大器增益不平坦对光纤CATV系统中CSO恶化的原因及其解决方法，并研究了光纤布拉格光栅在稳定980nm泵浦源输出功率和输出波长方面的应用；结合一个基于光纤光栅和光纤放大器的光纤用户接入网方案，对光纤用户接入网的若干问题进行了理论与初步的实验研究。

On the basis of the method of separating variables of sucker rod wave equation,in combination the matrix recursion technology with trigonometric series recursion technology,a kind of quick arithmetic of pump dynamograph in failure diagnosis technology of sucker rod pumping system is proposed.

在抽油杆柱波动方程分离变量法的基础上，将矩阵递推技术与三角级数递推技术相结合，提出了有杆抽油系统故障诊断技术中计算泵功图的一种快速算法，这种方法不仅适用于单级抽油杆采油系统，同时也适用于不同材质、不同杆径抽油杆组成的抽油系统。

Xwfd pre-stack migration based on wave equation has strong adaptability to the medium which has strong variable transverse velocity and it can be used for migration with dual-complexity.

波动方程的频率空间域有限差分深度偏移对介质速度横向变化有较强的适应性，适宜于复杂构造的偏移成像。

Shop assistant: Please check at the door.

店员：请您到门口柜台交费。

In the end, transportation of PAHs in the environmental matrix was preliminarily investigated and discussed according to PAHs data of soils and sediments from a certain region in Shanghai. The result indicated that there are two or more pathways on PAHs transportation in the environmental matrix.

最后，对上海特定地区内PAHs在环境介质中的迁移径途进行了分析讨论，结果表明上海市土壤和沉积物等环境介质中PAHs的迁移存在多种途径。