波的传播

The stability of algorithm, the condition of absorbing boundary and free surface boundary, the grid dispersion and the process of source are discussed in details. The numerous simulations of wave propagation are carried out in isotropic media, transversely isotropic media and anisotropic media induced by fractures. The difference between anisotropic and isotropic effects on surface records is analysized.

接着讨论了有限差分算子的稳定性和收敛性，以及吸收边界条件、自由边界条件、数值频散和震源的处理，对各向同性介质、横向各向同性介质以及裂隙引起的各向异性介质中传播的弹性波场进行了数值模拟，分析了多波多分量数据中的各向异性效应以及各向同性在地表地震记录中的反映。

Based on the nonlinear dispersion relation of electromagnetic wave in relativistic plasma, the nonlinear controlling equation for linearly polarized mode is obtained using Karpman's method. The modulation instability of intense laser pulse propagating through relativistic plasma is analyzed and the modulation instability growth rate as a function of perturbation wave number for laser beam propagating through relativistic plasma is given.

从相对论等离体中电磁波的非线性色散方程出发，利用Karpman方法获得了线性偏振波模所满足的非线性控制方程，在非线性色散方程和非线性控制方程的基础上对线性偏振激光在相对论等离体中传播的调制不稳定性进行分析，给出了调制不稳定的时间增长率与扰动态波数之间的函数关系。

There exhibited different characteristics in geoelectrical field anomalies, but they were closely related to tidal waves, for example, the increasing in amplitude at semidiurnal and semimonthly periods of tidal ...

分析异常产生机理认为，强震前的这种异常现象是震源区临震孕育过程中岩石弱化产生的电场异常，经自由空间或地壳传播到达地电台站后，与台站记录的电场潮汐波相叠加产生潮汐波增强或减弱现象。

A simplified theoretical analysis of the evanescent wave phenomenon was presented based on The Snell's Law.

运用Snell定律的波动形式解释了光在介质中传播时的消逝波现象，并探讨了提高消逝波光纤生物传感器分析灵敏度的方法。

Based on the two phase anisotropic model this paper analyses and presents the dynamic equations of elastic wave propagation, the Galerkin variational equation, and the finite element equation in two phase anisotropic media.

基于双相各向异性介质模型，首先推导了双相各向异性介质中弹性波传播的动力学方程及其Galerkin变分方程和有限元运动方程，然后给出了孔隙弹性波方程的有限元数值解法以及二维双相PTL介质中波场模拟的人为吸收边界条件。

In this method, the bucket sort is applied to manage wavefront nodes.

本文的快速算法改进了波前点的管理和子波传播的计算这两项耗时的工作，较大幅度地提高了传统算法的效率。

Utilizing the acoustic wave's characteristics, we can detect the interior structure and quality of the anchor system and, judge the anchorage state by beating the anchor bar's top with a hammer.

利用振动波传播具有的许多独特性质，可以在锚杆表面人工激发应力波来探测锚杆体系内部的结构和性质，以此来判断锚杆的锚固状态。

The application of the modified Rytov's method to the study of the optical-wave oblique propagation is discussed in this paper. The fluctuation index of the plane wave and the spherical wave is obtained.

将修正的Rytov方法推广应用于研究斜程传输问题，推导了平面波和球面波斜程传输时的闪烁指数，并根据ITU-R湍流大气结构模型，对平面波和球面波在不同传播高度、近地面风速、近地面大气结构常数、零内尺度以及非零内尺度下的闪烁指数进行了理论据导，做出了具体的数值分析。

The Y branch of low-loss and wide branch angle can be used as power dividers/combines in modulators, switches, interferometric devices, semiconductor laser arrays, planar silica-based waveguide lasers.

本论文在最后还应用改进的广角光束传播法研究和设计了新型的低损耗Y分支波导结构，这种波导结构同时具有大分支角度的特点，在光波导开关、M—Z干涉仪等光器件中具有重要的应用。

To further study this problem, the optical axis is rotated by an arbitrary angle. A striking phenomenon is discovered that the Brewster angle is always equal to the rotation angle. This is because the waves in the direction perpendicular to the optical axis become evanescent since the permittivity is positive while the permeability is negative in this direction.

然后进一步的研究了主轴不垂直于界面的情况，发现主轴转动的角度恰好等于此时的Brewster角，这是因为此时垂直于主轴的方向上介电常数为正磁导率为负，只有倏逝波而没有可传播的波存在，因此反射系数为0。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。