波的传播

The Green's tensor in frequency domain for cylindrical layered media was deduced from the 3-D Green dyadic for homogeneous media according to the propagation laws of waves in layered media,then the Green's tensor in spatial domain can be achieved with Fourier transformation ,which is a singular integral of wave-number.

根据分层介质中波的传播规律，由均匀介质中的三维张量格林函数得到频率域中柱状分层介质的张量格林函数表达式，经过傅立叶变换，可以得到空间域的格林函数，它是一个关于波数的奇异积分。

The Green's tensor in frequency domain for cylindrical layered media was deduced from the3-D Green dyadic for homogeneous media according to the propagation laws of waves in layered media,then the Green's tensor in spatial domain can be achieved with Fourier transformation,which is a singular integral of wave-number.

摘要根据分层介质中波的传播规律，由均匀介质中的三维张量格林函数得到频率域中柱状分层介质的张量格林函数表达式，经过傅立叶变换，可以得到空间域的格林函数，它是一个关于波数的奇异积分。

The results show that the density of gritstone is decreased gradually as the temperature increasing; so that it can be ignored; the longitudinal wave velocity is linearly decreased when the temperature increasing, and decrease rate of it follows the law of conic; R is one temperature point, which makes the law of tensile strength of gritstone after high temperature follows the law of parabola; and the maximal tensile strength appears when the operative temperature is R. After the temperature is higher than 700 ℃, tensile strength is small and change range is small when the temperature is increased.

结果表明，高温后粗砂岩的密度随试验温度的升高减小幅度很小，几乎可忽略不记；高温后试件中纵波波速的传播随温度升高基本呈线性降低，而减小率呈二次曲线规律变化；存在一个温度点R，使高温后试件的抗拉强度呈开口向下抛物线关系变化，且在R温度作用后试件抗拉强度达到最大；当试验温度大于700 ℃后，试件的抗拉强度变得很小，且当温度升高时变化幅度也很小。

Based on the analysis of mechanism and spread characteristics of the vibration wave produced by small diameter abnormal hammer tamping,and with the example of the engineering of dynamic compaction on a rubble fill site,the velocity-distance equation is built and the minimum safety distance is defined during small diameter abnormal hammer tamping with the maximum resultant velocity as the evaluation index.

在分析小直径异型锤强夯产生振动波的机理和传播特点的基础上，结合强夯处理块碎石土工程实例，以最大合速度作为强夯振动对环境影响的评价指标，得到了速度随距离增大的衰减公式和用小直径异型锤强夯具体能级下的最小安全距离，并验证了隔振沟有效性。

When semidiurnal tides move from the open sea to offing, they first get the high tide in the mouth of Samen bay, then bifurcate to two branches, one goes along the northwest direction and the other goes along southwest. And it can be easily found that the moving direction of diurnal tides is obviously different from semidiurnal tides.

半日潮波，由浙江东南外海向近海传播时，首先在三门湾湾口附近达到高潮，之后又分为南北两支，一支向西北传播，另一支向西南传播，而全日潮波与半日潮波传播方向有明显的不同。

Ground penetrating radar have so many advantage, therefore applied very extensive. But now it still exist some proportion to waiting for improvement, for example, distinguishing the GPR diagram primar ily stays in the foundation of the artificial naked eye distinguish and handcraft identify. Therefore it is beneficial to us to understand the electromagnetic wave spreading regulation, and scoop out much more useful information from the GPR wave inside, through forward simulate the familiar penetrating object in physical.

地质雷达具有如此多的优点，故应用十分广泛；但是目前地质雷达亦还有待改进之处，如雷达图像的识别主要还停留在人工的肉眼和手工的基础上；所以对常见探测对象的物理正演模拟，有助于我们了解电磁波的传播规律，挖掘雷达波中更多有用信息。

The results are verified from deep to extremely shallow water conditions. The shoaling waves, standing waves, 3D disturbance waves, tidal waves and solitude waves are simulated and verified,and waves over an underwater bar,the diffraction near single breakwater, breakwater gap, offshore breakwater, Breakhoff experiment are taken into account in this model. Furthermore, the wave harbor resonance under special topography, and "Bragg" resonance are simulated. The wave refraction problem under current fields,the nonlinear wave refraction-diffraction under "Arthur" current field, and the wave propagation under slowly varying current field are studied. The favorable calibrations show the model's feasibility in dealing with the wave nonlinearity and simulation in both deep and shallow water.

论文对深水至极浅水非线性波进行了较全面的验证，计算模拟了波浪浅化、立波、三维干涉波、潮波、孤立波以及波浪越过潜堤、单突堤绕射、双突堤绕射、岛式堤、Berkhoff实验和多连通水域波浪传播等问题，还对特殊地形条件下波浪发生港湾共振、布拉格共振进行了仿真；论文研究了水流中波浪传播折射变形问题，Arthur流场上非线性折射-绕射、水位缓变的转向潮流中波浪传播等缓变水流中波浪问题，各类问题的较好解决验证和表明了本文模式与方法具有适用于深浅水的可计算性与非线性。

When the speed of piton changes from several positive meters per second to negative during short time , a huge transient impacting force acts on the piston. The force spreads in the piston with stress wave. Converging force will become at some sections, which can destroy the piston.

从风动冲击器的工作原理可以得知，风动冲击器的活塞在高压气流的推动下，反复冲击钻头，冲击时活塞的速度由向下的几米每秒在极短时间内反弹为向上的速度，因而对活塞产生一个极大的瞬时冲击力，该力以应力波的形式在活塞内传播，就会在活塞的某些断面产生应力集中，造成活塞的破坏。

The torsion meter can be used to mock the torsion waves' spreading and destruction, it also can be used to make traditional rocking bed experiment, bouncing bed experiment and three dimension mixed experiment.

扭仪除了可以用来模拟扭波的产生传播和破坏而外，还能用它来作传统的摇床式实验、蹦床式实验和三维混合实验，是一个万能实验仪，可用它来证明各种传统的实验结果均与地震破坏相悖，都不能做为设防抗震的依据。

The first part is about history and independent revolution of Belgium, and the second monarch of Belgium—Leopold II .Then classifies and narrates the article according todiplomatic , economy , religion , education. Narrates separately the diplomatic activity between China and Belgium, the construction of the Beijing-hankou railroad, the spreads of the Congregation of the Immaculate Heart of Mary, sending students to study in Belgium for four pieces.

首先简单叙述了比利时的历史和比利时的独立革命，以及比利时第二任君主利奥波德二世，接着按外交、经济、宗教、教育分类叙述，分别论述了中比之间的外交活动、芦汉铁路的修建、圣母圣心会在华的传播、留比学生的的派遣四个方面。

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％。