波

In this algorithm, the direction-of-arrival is assumed to be a discrete random variable with a priori probability density function defined on a set of candidate points. Whether or not the secondary sample is required is based on the a posteriori probability distribution of a set of candidate point"s, which can be calculated from the array received signals. And then, the resulting beamformer is a weighted sum of the beamformers pointed at the latest set of point"s, which are combined according to the value of the a posteriori probability for each pointing direction.

在该算法中，期望信号的波达方向被看作是一个定义在若干候选波达方向上的离散随机变量，由阵列接收信号计算出各候选波达方向的后验概率，并将后验概率的分布作为是否需要进行二次采样的判断标准；随后，对各波达方向上的波束成形权值线性加权，便可得到自适应波束成形器，权系数为各候选波达方向的后验概率值。

Therefore, the multi-stage interaction structures with losses and severed structure were more stability for absolute instability and gyrotron backward oscillations. This study presents a nonlinear analysis of typical oscillations, including absolute instability, gyrotron backward oscillation and reflective oscillation. The multi-stage gyro-TWT seem to increase effectively the start-oscillation currents of the absolute instability, gyro-BWO, and reflection oscillation.

所以在本研究分析中，藉由了解磁旋行波放大器中的自发振荡物理原因及特性，将有助於高功率放大器的设计，并且引用非线性程式进行磁旋行波放大器稳定分析，并且采用兼具隔离管及散布式损耗结构的磁旋行波放大器，同时提升绝对不稳定、磁旋返波振荡及反射振荡的稳定性能有效提升磁旋行波放大器输出功率和频宽。

The results are presented and compared with the available results of other authors, which shows satisfying agreement. And a submerged body beneath the free surface in accelerated motion is considered; the numerical results of instant wave resistance and free surface elevation are presented and discussed.

对非定常线性兴波问题的求解，第5章作为算法的验证，从较简单的近自由面运动潜体的非定常兴波问题入手，首先对无限水深近自由面潜体突然加速和渐近加速的非定常兴波问题作了计算，给出了非定常兴波波形和非定常兴波阻力随时间的变化曲线，计算结果与其它文献给出的结果进行了比较，其吻合程度令人满意。

As the foundation of ultrasonic testing of composite materials, this thesis is intended to explore in detail a number of features of wave propagation in anisotropic plates, and the following essential problems will be considered:(1) Propagation of plane bulk waves in homogeneous and orthotropic anisotropic media;(2) Lamb wave propagation in multilayered anisotropic plates;(3) Influence of isotropic solid or liquid loading on Lamb wave propagation in anisotropic solid media;(4) Influence of interface layers on Lamb wave propagation in layered anisotropic composite laminates;(5) Dispersion characteristic analysis of attenuation Lamb wave while existing an thin viscous layer which is used for simulating the poor curing in adhesively bonded joints.

作为复合材料超声检测的基础，本文研究了如下国际前沿性的课题：（1）平面体波在正交均匀各向异性媒质中的传播；（2）多层各向异性媒质中Lamb波的传播；（3）各向同性固体或液体负载对各向异性固体媒质中Lamb波传播的影响；（4）界面层对层状各向异性复合媒质中Lamb波传播的影响；（5）胶粘剂未固化而呈现粘弹性时粘接结构中衰减Lamb波的频散特性分析。

The linear theory of antisymmetric ducted gravity waves supported by mesospheric thermal duct is presented, propagation and evolution of gravity wave packets in thermal duct is also simulated by using a nonlinear two-dimensional model. Numerical results show that lower atmospheric wave disturbance can penetrate into the duct area and be trapped.

给出了重力波在中层大气温度波导中的反对称形式导制传播的线性理论模型，并采用二维非线性的数值模型对重力波波包在中层大气温度波导中的传播和演变过程进行了模拟研究。

The characteristics of the three main parts of mono-pulse slotantennas——longitudinal radiating slot, center-inclined slot and magic T using couplingslot, are analyzed. Also the influence of the design parameters, such as the length and width of the slot etc., are analyzed. The engineering curves of design are given, and some beneficial conclusions are gained too. These also give powerful supports for the design of slot antennas.

针对毫米波单脉冲波导缝隙天线的三个主要组成部分——波导宽边辐射纵缝、波导宽边中心斜缝和宽边缝隙耦合魔T的特性及其各项设计参数(如缝隙长度、宽度、半高波导、全高波导等)对性能的影响进行了较为全面、详细的分析，给出了相应的工程设计曲线，得到了一些有益的结论，为高性能波导缝隙阵列天线的设计提供了有力的参考。

Fifthly, the conception and the method of image compress is dissertated, also discusses the conception of wavelet transformation、continuous wavelet、discrete wavelet and multi-resolution analyses、Mallat algorithm, and do further research on the characteristic of wavelet images、the choice of wavelet bases and the continuation of image border, and based on this work, the way of freight train images compression combined with the wavelet and JPEG is put forward.

第五，论述了图象压缩的概念、方法，对小波变换的概念、连续小波、离散小波以及多分辨率分析、Mallat算法进行了讨论，并对小波图象的特点、小波基的选择以及图象边界的拓延进行了深入研究，在此基础上提出了小波和JPEG相结合的货车图象压缩方案。

The results show that:(1) The space-charge fields(include dc space-charge fields and ac space-charge fields) have important effect on the beam-wave interaction output power, make the saturated output power lower, saturated position delay;(2) The back-radio excited by the electron beam has little effect on the output power, and can be ignored;(3) The transverse motions of electron beam has some effect of the output power;(4) The means of phase velocity taped and bunch compression can improve the relativistic TWT efficiency, especially bunch compression can greatly improve the efficiency.

五、分析了相对论行波管三维非线性特性，分析结果表明：(1)空间电荷场（包含直流和交流空间电荷场）对注波互作用输出功率影响很大，会造成饱和输出功率减小，饱和位置推后；(2)电子注激发的反向辐射对输出功率影响比较小，基本上可以忽略不计；(3)电子注横向运行对注波互作用的直接影响比较大；(4)通过改变耦合腔内半径来调节慢波结构相速，采用相速跳变和预群聚的方法可以改善相对论行波管的效率，特别是采用预群聚方法，可以尽量提高相对论行波管的效率。

Four-port network with partial height cylindrical objects in rectangular waveguide junctions (i.e., Four-port rectangular junctions), multiple-stepped rectangular waveguide bend and T-septum rectangular waveguide junction are modeled by full-wave mode matching method in order to quickly design the combline cross-coupled filter, corner waveguide diplexer, generalized chebysheve waveguide filters and diplexers with high efficiency in this paper.

本文将它运用于矩形波导接头中带通用圆柱杆的四口网络、多阶梯矩形波导弯头和T—septum矩形波导接头的全波建模，有助于快速高效设计梳状广义切比雪夫滤波器、拐弯波导双工器、广义切比雪夫波导滤波器和双工器。

Bispectral analysis and dynamic spectral analysis are applied to the wind data of June, 1997, measured by MF radar in Yamagawa, Japan, to investigate nonlinear interactions among planetary waves, tidal waves and gravity waves in the mesopause region.

对中纬度中频雷达1997年6月82km高度的小时平均风场数据进行了动态谱分析和双谱分析，得到了中层顶区域谱行为具有多样性和各向异性的特点，以及行星波、潮汐波和重力波之间相位相干的现象，讨论了中层顶行星波、潮汐波和重力波之间存在非线性相互作用的可能性。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。