波

The composite scattering between dielectric sea surface and a conducting plate above it is calculated by using Physical Optical method and reciprocity theorem. Meanwhile, the dependence of the plate size on the composite scattering field is considered. The Doppler spectrum and the chaotic characteristic for the time series of composite scattering field are analyzed. Finally, artificial neural networks and wavelet analysis are introduced into the study of the sea clutter to realize the purpose of target detection, the factors which affect the detection of the target are discussed and the solutions to these problems are given.

同时利用物理光学近似结合互异性原理计算了介质粗糙海面与其上方导体运动平板的复合散射，考虑了平板尺寸对复合散射场的影响，并对复合散射场时间序列进行了多普勒谱分析和混沌分析，最后将人工神经网络和小波分析引入到海杂波的分析当中，实现了海杂波中目标探测的功能并讨论了影响目标探测功能的因素以及解决这类问题的方法。

An accurate measurement scheme is proposed for testing the error of cone prisms with Hartmann wavefront sensor. The measurement theory was discussed, the reconstruction of the wavefront reflected from a cone prism was studied, and the relation between the wavefront characteristics and the errors of a cone prism was given.

因此，提出一种用哈特曼波前传感器全面检测角锥棱镜角度误差和面形误差的技术方案，从理论上分析了哈特曼法的测量原理，深入研究了光经过角锥棱镜后的波面重建，给出了波面特征与角锥棱镜误差参量之间的关系。

It is difficult to get eigen equation of the regular polygon cross section waveguide.

其中平板波导和圆截面波导已经得到了比较充分地研究[1-2]，但对正多边形截面波导的研究，一直没有简便有效的方法。

Numerical results demonstrated that there are three kinds of the instability for the under-expanded supersonic jets according to their shock cell structure patterns:(1) the regular reflection shock cell with a single shear layer,(2) the Mach reflection shock cell with two shear layers and (3) the curved Mach stem with a relatively high expansion ratio.

计算结果表明欠膨胀超声速射流的失稳机制根据射流激波结构的特征可分为3种失稳模式：具有规则反射激波结构和单一剪切层特征的射流不稳定性；带有马赫反射激波结构和双剪切层特征的射流不稳定性；具有弯曲马赫杆和高度欠膨胀射流的不稳定性。

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。

A multi-layer viscoelastic model is developed, and the boundary-value problem under linear conditions about the multi-layer model is solved. Calculated values of wavelength and damping rate of wave height are compared with measured data. It is showed that the transformation of regular waves over muddy bottoms can be successfully predicted by this model.

建立了多层粘弹性体模型，求解了多层模型在线性化边界条件下的定解问题，得到了规则波在泥床上传播时波要素变化的理论值，并同大量实验数据进行了比较，结果表明，多层模型能够成功地预报规则波在泥床上的传播规律。

Although noise is relatively weak in the case of large offsets, seismic wave field is very complex. There are a variety of high-energy regular waves such as first arrivals and refractions.

在大偏移距处，虽然一些随机噪音会相对减弱，但地震波场十分复杂，各种有规律性的波，如直达波，折射波的能量很强。

The system provides a choice of three different effects toning lifting, improving circrlation and mrscle relaxtion. It does this by varying the shapes of the impulses or waveforms. The waveforms are sine ramp and square.

花想容微波拉皮仪提供了三种不同的效果以供我们选择：收紧和提升，改善血液循环和放松肌肉，它靠几种不同的脉冲或微波来达到这种效果，这些微波是：正弦波、斜波、方波。

The target model is structured using vector resultant of multi-scatter center. Second, based on the character of land clutter, different kinds of land clutter are simulated. Last, the hardware of the system is designed.

首先分析了目标的反射特性，利用多散射点合成的方法建立目标回波模型；然后根据地杂波的特性，模拟产生了不同分布类型的地杂波；最后设计了脉冲体制目标模拟器的硬件实现方案。

Taking advantage of retractility and time-delay characteristics of wavelet, this paper solves the problems of fixed resolving power and large redundance of the information caused by traditional sonogram analysis by choosing the scale of wavelet correctly.

本文将离散小波变换应用于蝙蝠回声定位叫声的分析中，利用小波的伸缩和时移特性，通过对小波尺度的适当离散，解决了传统语谱分析的分辨率固定、信息冗余量大的问题。

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％。