衰减系数

Based on basic theory of elastic wave propagation, wave equation forpropagation of elastic wave in 2 dimension vertical inhomogeneous mediumof similar concrete cutoff wall model is developed. 2 dimension elastic sheetof concrete cutoff wall is established to research law and energy distributionrelations between propagation, attenuation, reflection and transmission ofelastic wave in concrete cutoff wall; Based on the concept of resolution, thecontent of vertical reflection method used to inspect concrete cutoff wallresolution is raised and factors will have influences on resolution are analyzed,expression of defective layer composite reflection factor and detectabledefective layer maximum thickness are developed; Relations between allsteps of sampling system of vertical reflection are build, the influence ofcentrum characteristics and receiving sensor on testing results are analyzed,therefore parameter requirements for testing instrument and parameter selection principle of collected parameters are raised.

2从弹性波传播的基本理论研究出发，推导了弹性波在类似混凝土防渗墙模型的二维垂向不均匀介质中传播的波动方程式；建立了混凝土防渗墙二维弹性薄板模型，研究弹性波在混凝土防渗墙中的传播、衰减、反射、透射规律及能量分配关系；从分辨率的概念出发，提出了垂直反射法检测混凝土防渗墙分辨率的内涵，对影响分辨率的因素进行了分析，推导出了缺陷层复合反射系数、可检测缺陷层极限厚度的表达式；建立了垂直反射法采样系统各环节之间的关系，研究分析了震源特性、接收传感器对测试结果的影响，提出了对测试仪器参数的要求及采集参数的选择原则。

The previous researches have been done experiments mostly in the Water tank. In order to simulate turbulence of flow in river and research its characteristics, the characteristics of turbulence are studied by experiments in the water channel with ADV technique. The research results indicate that R.M.S. velocity linearly relates to the oscillating-grid frequency; R.M.S. velocity decays by power exponent relates to the distance from the grid midplane; and the relationship between the geometrical factors and the free movement space of water is direct proportion.

以往研究大都在水箱中对振动格栅紊流特性进行实验研究，为能模拟天然河道中的紊流，研究天然河道中紊流特性，利用ADV技术在水槽中对振动格栅紊流进行了实验研究研究结果表明：均方根速度与格栅振动频率成线性关系；均方根速度与距格栅中平面的距离成幂指数关系衰减；几何系数与水的自由运动空间成正比关系。

Lugalbanda was a god and shepherd king of Uruk where he was worshipped for over a thousand years.

Lugalbanda 是神和被崇拜了一千年多 Uruk古埃及喜克索王朝国王。

I am coming just now,' and went on perfuming himself with Hunut, then he came and sat.

我来只是现在，'歼灭战perfuming自己与胡努特，那麼，他来到和SAT 。