查询词典 type A wave

Based on the basic principle of reflection and transmission in the process of the propagation of logitudinal wave, this paper recounts a new theory and method for the application of pile body completeness inspection data with reflection wave method to the quantitative determination of apparent reflection coefficients and the round travelling time of reflection wave.

摘要从纵波传播过程的反射和透射的基本原理出发，介绍了反射法桩身完整性检测数据在频率域中定量确定视反射系数和反射波往返时间的一种新的理论和方法。

The main contents include the ray phenomenon and its generation conditions; the deduction and physical illumination of wave action conservation equation and wave number conservation equation; ray theory for sinusoidal waves; Fermat's principle; the variation of amplitude in the case of straight and parallel depth contours and circular depth contours; the amplitude near the caustics; wave trapping; deduction of mild-slope equation and the relevant numerical solution methods.

讲授折射现象及其发生的条件；波作用守恒方程和波数守恒方程的推导及物理解释；稳恒正弦波的控制方程及射线方程；费马原理；利用射线方程研究等深线是平行直线和圆周线时波振幅的变化，特别是焦散线附近波高的变化以及由此而产生的波的俘获；缓坡方程的推导及有关的数值求解方法。

The second feature might be the spatial wave which appears as a progressive wave in the area. The direction of the wave movment appr...

采用多维谱分析方法，探讨了各季节的南方涛动指数与气压场的振荡特性，结果表明它们之间存在准3.5年的耦合振荡，且以南方涛动变化超前气压场为主要特点，冬季更为显著。

Then by measuring the pulse wave propagation time between the progressive wave and reflected wave, we can find the relationship of the time and the blood pressure, and establish the related systolic blood pressure measurement equation.

具体方法是通过交替点亮红光和红外光获取容积脉搏波，经放大滤波及信号处理后得到加速脉搏波，通过测量其中推进波和反射波之间的脉搏波传播时间来建立与血压的关系。

It has been proven that, from the propagation process of the tidal waves and wave energy rates, the whole radial sandbanks area is controlled by the progressive tidal wave in the south and the rotational standing tidal wave in the north.

另外还研究了辐射沙脊群海域的余流及余流量的分布，发现在潮流沙脊两侧存在平面余环流，余环流将有利于泥沙在脊顶沉积，与潮流沙脊的维持发育密切相关。

Firstly, radial horizontal component and transverse horizontal component are derived from tri-channel seismic data at the surface and the bedrock in borehole array by back-azimuth decomposition method, and the histories of radial and vertical components are divided into two parts by Sg wave arrived time. Moreover, it is supposed that transverse horizontal components are made up of SH wave, while vertical component and radial horizontal component are constituted by P-SV wave system.

针对钻井台阵的两处三分量加速度记录，根据反向方位角将两水平分量分解为径向水平分量和横向水平分量，假设横向水平分量由SH波系组成，竖向分量和径向分水平量由P-SV波系组成。

in this paper,the stealthy target′s millimeter wave radiation character is studied.the millimeter wave attenuation induced by sea fog is analyzed.and the detecting capability of the ground-based passive millimeter wave radiometry arrays is discussed.according to one dimension 32 channel 8 mm radiometry arrays detecting stealth target,we have a simulation.the results of the simulation show that it is an efficient way in the thick sea fog condition.

摘 要：研究了空中隐身目标的毫米波辐射特性，分析了浓海雾对毫米波辐射信号的衰减，并对无源毫米波辐射计阵列探测热辐射源的性能进行了分析。在理论建模的基础上针对一维32通道8 mm辐射计阵列探测空中隐身目标进行了仿真实验，结果表明毫米波辐射计阵列在浓海雾气候条件下探测空中隐身目标是一种非常有效的手段。

The sediments of delta front around wave base plane are eroded by wave action and took along to redeposit below wave base plane, during which turbidite is formed.

波浪作用可以侵蚀浪基面附近的三角洲前缘砂体，并在回流作用下携带至最大浪基面之下再沉积，沉积过程中形成小型浊积体。

Depending on the character of Lamb wave propagation , thedamage scat tering signals were time reversed and reemit ted to the damage , and then they will arrive at the damage synchronously so that the damage scat tering signal caught again will be amplified. Details about the time reversal amplifying process were analyzed and given. Based on the focalization ability of time reversal theory to the wave origin , the wave propagation was rebuilt by an image method which displays the damage as the focusing point .

根据信号传播自身的特性，研究采用时间反转聚焦方法使损伤散射信号能量叠加放大，从而提高信号的信噪比，分析给出了具体的损伤信号时间反转聚焦增强过程；利用时间反转法对波源的自适应聚焦能力，重建信号传播波动图，通过信号聚焦显示损伤位置和区域。

On the basis of shock wave characteristic of the supersonic projectile and the detailed analysis of measured datas,a method of decomposing and reconstructing the trajectory shock wave signal and muzzle blast wave signal is proposed and the characteristic parameters for positioning sound source and calculating trajectory vector with regular tetrahedron detection array are extracted.

根据空气动力学原理，在阐述超音速弹丸的弹道波特性的基础上，通过详细分析实测的声信号，提出了弹道波信号和枪口冲击波信号的小波分解和重构方法，提取了利用正四面体探测基阵进行声源定位和弹道矢量计算的特征参数，获得了满意的实验结果。

So it was last week in Selma , alabama.

上星期在亚拉巴马州塞尔马市发生的事件也是这样一个转折点。

The group also spearheads various social programs in China.

该组织还带头参与中国的各种社会活动。