激波

along with the development of digital technology,digital filters are widely used in many fields,this paper introduces how to design a iir digital notch filters in matlab environment.the design of digital notch filters can be achieved through three steps:firstly,the design of analog lowpass filter; secondly,it is analog lowpass to analog band stop filter conversion;at last,using the bilinear transformation make the analog notch filters change into digital notch filters.the paper also introduces how to design the transfer function of the digital notch filters using all the zeros and farthest points at the same time,it also introduces the program of the digital notch filters under butterworth analog lowpass prototype.

摘 要：随着数字技术的发展，数字滤波器在许多领域得到广泛的应用。研究一种在matlab语言环境下设计iir数字陷波滤波器的方法，在数字陷波滤波器设计过程中，先进行模拟低通滤波器的设计，然后进行模拟低通/模拟带阻滤波器转换，最后采用双线性变化法将模拟陷波滤波器转化成数字陷波滤波器。提出一种用所有零点和极点来表达数字陷波器传递函数的方法，同时给出以巴特沃斯模拟低通为原型设计数字陷波滤波器的程序。关键词：无限冲激响应；巴特沃斯滤波器；数字陷波滤波器；matlab；双线性变换

This method decomposes wave-front phase to a linear combination of orthonormal basis functions, According to the covariance of weight coefficient, a random wave-front phase is realized.

协方差冲激函数产生法对连续波前相位进行冲激函数正交分解，根据正交分解系数的协方差模拟平行光通过大气后的瞬时波前相位。

By analyzing the behavior of metallic surface plasmon wave, the resonance condition and origin of frustrated total reflection are got.

分析了金属表面等离激元波的行为，得到了等离激元波与入射电磁波的共振条件及受抑全反射的产生原因。

This paper introduces the generating mechanism, theoretical calculation and lab test of self-excited wave.

介绍了自激压力波产生的机理、理论计算及室内试验情况，自激压力波频率小、幅值大，可对油层产生连续波动作用。

Theory analysis and the measured data are shown that excitation pulse in pile integrity testing is silimar to half-period of the sine curve, and different exciting methods produce signals with different period of time, so its frequency composition is also different.

理论计算及实测资料表明，反射波法基桩动测激振信号近似为半周期正弦波，不同激振方式产生的桩顶速度脉冲信号宽度不同，相应频率成分也就不同。

The ground-state binding energy of an exciton confined in quantum wires and quantum wells in the presence of a uniform electric field has been calculated under the effective-mass approximation using variational approach.

本文采用变分法研究了外加电场下无限深方形量子线中重空穴激子的束缚能，我们用平面波展开的方法求解在电场作用下无限深方形量子线中电子和空穴的基态能和基态波函数及低激发态的能量和波函数，并用所得到的波函数进一步计算激子的基态及低激发态的束缚能，最后计算了激子的Stark能移。

In this dissertation, InGaAs/InGaAsP/InP MQW microdisk laser and its characterization were presented. Some conclusions are as following: the characteristics of lasing threshold was discussed by using rate equation. The dependent relations between threshold and cavity volume, spontaneous emission coupling efficiency β were investigated. The whispering gallery mode and spontaneous emission in a microdisk geometry were then studied. Almost all spontaneous emission was coupled into the lowest order TE mode when the normalized thickness of photonics well was between 0.15 and 0.5. The design principle and device process of InGaAs/InGaAsP/InP MQW microdisk laser were presented. The microdisk lasers with the diameter of 8μm, 4. 5μm and 2μm were succesfully fabricated by using etching techniques. The pulse lasing thresholds for the microdisk with the diameter of 8μm and 4. 5μm were 170μW and 15μW, a record results compared with the published in the literature. The cw lasing threshold for a 2-μm-diameter microdisk was only a few μW. We haven't found similar report up to now. To solve the problem of directional output in a microdisk laser, the power coupling efficiency in a double disk geometry was investigated with the theory of waveguide mode couple. A new structure of electrically pumped microdisk laser with output waveguide was designed, making a foundation for the practical use of microdisk laser.

本文主要研究InGaAs/InGaAsP/InP多量子阱半导体碟型激光器的研制和特性表征，并取得如下结果：利用速率方程理论讨论了激光器激射阈值的特性，分析了阈值与腔体积和自发发射耦合系数β之间的关系；讨论了微碟光子阱结构中的自发发射特性和微碟中WGM模式特性；光子阱结构在其归一化厚度在0.15-0.5之间时，几乎全部自发发射进入到最低阶TE模式中；研究了InGaAs/InGaAsP/InP多量子阱微碟激光器的结构设计原理和器件的制备工艺；利用刻蚀方法成功制备出直径分别为8μm、4.5μm、2μm的碟型微腔激光器；直径8μm和4.5μm的微碟脉冲光泵浦激射阈值分别为170μW、15μW，是目前所见文献报导中比较低的；直径2μm的微碟连续光泵浦激射阈值仅几μW，目前尚未见到达到类似结果的研究报导；为解决微碟激光器激射光定向引出的问题，通过波导耦合模理论分析了双层碟之间功率耦合效率；据此设计了新型带耦合输出波导的电泵浦微腔激光器，为进一步研制可实用的电泵浦微腔激光器打下基础。

SBS partial phase-conjugate compensating phenomenon has been researched experimentally.The difference between single-transverse-mode laser SBS and wave-front-distorted laser SBS were analyzed illustratively.

通过实验观察了受激布里渊散射相位共轭波前补偿现象，分析了单横模激光、波前弱畸变及强畸变激光受激布里渊散射现象的差异。

3D effect is analyzed and the average velocity of wave propagating in the pile, which mainly influences inverse interpretation, is discussed. Finally, the theory results are verified by model experiment. It is shown that 3D results have the same phase with ID results. The pile radius, the duration of impulse, the ratio of hammer radius to pile radius and shear velocity of the soil around the pile have influences on 3D effect. The best position of receiver is 0.55R from the pile center. The average velocity of wave propagating in the pile reduces due to transversal inertia effect and 3D effect.

结果表明：三维曲线与一维结果在相位特征上一致；波场图直观地反映了波在桩中的传播规律；三维效应与桩径、激振脉冲宽度、相对激振半径及桩周土剪切波速有关；传感器放在0.55R处可以得到干扰较小的信号；三维效应和横向惯性效应的存在会使桩中的波速减小，土的性质对波速影响不大；反演精度与缺陷的性质、激振条件有关。

First, the effects of magnetic RAM relaxation time and the rise-time of incident pulse signal on reflection signal are discussed, the relationship between the rise-time of incident pulse and relaxation time based on the energy of reflection signal is revealed. Then, the effects of magnetic hysteric, susceptibilities and saturation upon reflection signal are analyzed, the results reveal the reflection of RAM target and UWB signal design. In the meantime, dielectric relaxation time effect about dielectric RAM target is analyzed simply, and the effects of relaxation time and the width of incident pulse upon reflection signal are probed. Finally, a few RAM targets are measured in the chamber using the impulse radar experiment system which is developed by the team of anti-stealth impulse radar on Department of Electrical Engineering, National University of Defense Technology. The experimental results show the similarity of the rule of echos with the theory. From the compared results of different tagets, we concluded, compared with 15% wideband sinusoidal signal, the impulse signal has increased 10～12dB energy from the same loaded RAM target; this, in turn, shows the nonlinear effects of RAM to the echoes, and the potentiality of the impulse signal to RAM targets.

首先分析了磁性RAM的弛豫时间及入射脉冲信号的上升时间对反射信号的影响，从反射信号能量角度出发，给出了入射脉冲上升时间与弛豫时间的关系；接着分析了磁性RAM的磁滞特性、磁化率及磁化强度对反射信号的影响，给出了RAM目标辐射和有关UWB信号设计的一般性结论；其次，对介电RAM的弛豫时间效应作了简单的分析，探讨了介电弛豫时间及入射脉冲宽度对反射信号的影响；最后利用国防科技大学电子技术系&反隐身冲激雷达技术研究组&研制的冲激雷达实验系统，在微波暗室中对几种不同的RAM目标进行了测量，结果表明：其反射波形的基本规律与上述理论分析相一致；从各种不同目标回波的能量对比结果得出，涂覆RAM目标对冲激信号的吸收比15％带宽的正弦信号要小10～12dB，证实了RAM的非线性效应对回波的影响，也证实了冲激信号反隐身的潜力。

She gently rebuff ed him, but agreed that they could be friends

她婉言拒绝了，但同意作为朋友相处。

If in the penal farm, you were sure to be criticized.

要是在劳改农场，你等着挨绳子吧！