查询词典 undamped wave

The research which is the important part of the tunable erbium-doped fiber laser is composed of two main parts: 1. the gain part of the tunable erbium-doped fiber laser, which in fact is an erbium-doped fiber amplifier, its output characteristics are discussed both in theory and experiment, and the differences are also discussed between theory and experiment; 2. the saturated absorber part of the tunable erbium-doped fiber laser, also the part to narrow the line width of the fiber laser. The line-width narrowing mechanism in fiber laser induced by unpumped Er-doped fiber is presented from the aspect of coupling wave equation, and the main factor is considered as the standing wave induced by interference. The line-width is narrower when the standing wave is stronger, and the narrowing effect disappears with the disappearance of the standing wave. In the experiment, when adding a Faraday mirror in the laser cavity to remove the standing wave , the narrowing effect disappears. So the theory is proved by the result of the experiment.

本课题的研究内容是集成光学声光可调谐掺铒光纤激光器的重要组成部分，主要分两部分：1、声光可调谐掺铒光纤激光器中增益部分的研究，相当于对掺铒光纤放大器的研究，理论上对掺铒光纤放大器的输出特性进行分析，实验上实现了掺铒光纤放大器系统，并将实验数据与理论计算数据进行对比，分析了误差产生原因；2、声光可调谐掺铒光纤激光器中饱和吸收体部分的研究，即压窄光纤激光器输出线宽的研究，从耦合波方程出发，理论上解释了未泵浦掺铒光纤压窄光纤激光器线宽的原理，分析了影响该作用的主要因素是未泵浦掺铒光纤中相对传输的光干涉形成的驻波：驻波越强，压窄效果越好，相反当没有驻波时，没有压窄效果，在实验上通过在激光器腔内加入法拉第旋转镜使驻波消失，同时压窄效果消失，从而验证了理论分析的正确性。

In the research on the backward-wave oscillation suppression the startoscillation current which is derived from Two-wave theory approximately is given up. Four typical un-uniform slow wave structures start-oscillation current equations are derived by backward-wave amplifing gain expressions with the Two-wave theory. Then the start-oscillation current rates I〓/I〓 between ununiform circuit and uniform circuit of the four structures have been got.

在返波抑制问题的研究中，从二波理论出发，抛弃了二波理论中从起振条件出发来得到起振电流近似表达式的方法，而是利用二波理论的基本关系式分别推导出了四种典型实用的非均匀输出线路的返波增益表达式，采用计算返波增益的方法来得到四种非均匀输出线路的起振电流与均匀输出线路起振电流的比值I〓/I〓。

The paper has studyed the characteristics of seismic wave field in the media of EDA, and has made out three aspects of numerical simulation on wave field features by using definite difference: The simulation of P-wave ground seismic logs in the media of EDA; the diagnostic complication of seismic wave field in cranny belts due to the scattering of cranny wrappage; the decreasing of amplitude and the reversing of polarity of the wave reflected on not only the top but also the bottom of fracture zone.

2通过罗67井岩芯的系统研究表明，泥岩的横波和纵波速度随温度增大而降低，一定温度条件下随为压力而增大；泥岩裂缝的测井曲线一般表现为高电阻率、负自然电位异常、低声波时差，利用该规律可以半量定地识别划分泥岩裂缝储层特征，为解决不同度数据的相互匹配这一重点和难点问题提供了思路和方法。

At present, millimeter wave response of K wave band was applied in American BCIS system, the millimeter wave identification was used in French BIFF system, beaconing identification of millimeter wave was applied in British M-TICE system, laser enquiry and response of L wave band was used in Germanic ZEFF system.

目前，美BCIS系统采用K波段毫米波问答，法BIFF系统采用毫米波识别，英M-TICE系统采用毫米波信标识别，德ZEFF系统采用激光询问和L波段应答。

The growth relationship between spectrum parameter and fetch were studied, from which three parameters and overshot phenomenon that appears during wind wave spectra developing were tested, and an equation describing the growth of three-parameter spectra with wind wave was obtained With the equation, the spectra of wind waves were obtained at zero-dimensional fetches of 300, 500, 2000, 5500, 10000, and 15000, and the overshot was described more clearly. However, the overshot does not exist in the whole process of wind wave spectrum development as stated previously by Hasselmann, but in the early stage of the development only, extenuates with wave growth and then disappears when the wave fully grows.

基于已得到的谱参量随风区的变化关系，对三参量风浪频谱以及风浪频谱成长过程中存在的&超射&现象作深入的研究，得到三参量风浪频谱随风区的成长关系：在此基础上，得到无因次风区：300、500、2000、5500、10000、15000下，风浪频谱的谱线，从而直观地描述了风浪频谱成长过程中的&超射&现象，并认为在风浪频谱的成长过程中确实存在着&超射&现象，但是该现象并不如Hasselmann等提出的理论中阐述的那样存在于风浪频谱成长的全过程，而是仅存在于风浪频谱成长的初期。

The numerical results of stationary and transient Green'sfunction for high-velocity surface-head wave on some selected crystals are comparedThrough the above analyse,it is indicate that the first arrival wave mode is thelongitudinal-wave head-wave,and its propagate velocity is equal to the groupvelocity of the longitudinal bulk wave alone the surface.Furthermore,this modedoes not have the Δv/v effect,i.e.,its velocity is the same no matter the surface isfree or metalized.

通过对表面激发的瞬态和稳态Green理论分析和数值计算，表明在压电晶体表面上实际上看到的最高速的最先到达的波动模式是纵波头波，它具有沿表面纵波的群速度，而且对压电晶体，它不具有Δv/v效应，即在自由表面和金属化表面其传播速度是一样的，而压电晶体表面波及伪表面波均存在Δv/v效应。

First the relationship of shoaling coefficient and relative water depth in regular and irregular wave fields has been analyzed. The experimental result shows that shoaling wave height decreases at first then increases until wave breaking. The broken wave height of regular waves is smaller than irregular waves with same wave steepness and relative water depth.

本文首先就规则波及不规则波实验分析波浪的浅化系数与相对水深之关系，实验结果显示浅化波高有先减后增之趋势，在碎波前达到最大，碎波后之波高在相同水深与深海波浪尖锐度成反比，规则波碎波后波高较不规则波小。

The results are verified from deep to extremely shallow water conditions. The shoaling waves, standing waves, 3D disturbance waves, tidal waves and solitude waves are simulated and verified,and waves over an underwater bar,the diffraction near single breakwater, breakwater gap, offshore breakwater, Breakhoff experiment are taken into account in this model. Furthermore, the wave harbor resonance under special topography, and "Bragg" resonance are simulated. The wave refraction problem under current fields,the nonlinear wave refraction-diffraction under "Arthur" current field, and the wave propagation under slowly varying current field are studied. The favorable calibrations show the model's feasibility in dealing with the wave nonlinearity and simulation in both deep and shallow water.

论文对深水至极浅水非线性波进行了较全面的验证，计算模拟了波浪浅化、立波、三维干涉波、潮波、孤立波以及波浪越过潜堤、单突堤绕射、双突堤绕射、岛式堤、Berkhoff实验和多连通水域波浪传播等问题，还对特殊地形条件下波浪发生港湾共振、布拉格共振进行了仿真；论文研究了水流中波浪传播折射变形问题，Arthur流场上非线性折射-绕射、水位缓变的转向潮流中波浪传播等缓变水流中波浪问题，各类问题的较好解决验证和表明了本文模式与方法具有适用于深浅水的可计算性与非线性。

In the process of impact of abrasive jet on rock, resulting dynamic stress plays an important role in rock destruction. The stress wave resulted makes local rock tensile and shearing, then makes rock destructed. In the conditions of some hypotheses, the mechanical model that rock is applied by stress wave, i.e. jet wave basic equations, are set up by wave theory, and the formula of the maximum normal stress resulted by stress wave is deduced according to known boundary conditions.

描述了岩石材料在磨料射流的冲击下破坏的主要原因，分析了应力波就是岩石局部受到拉伸和剪切并最终使岩石发生破坏的根本因素，在这一假设的前提下采用波动理论建立了岩石受应力波作用的力学模型即射流波动的基本方程，在已知的边界条件下推导出了由波动引起的最大正应力的计算公式。

In this paper, we present a wave theory based rendering technique: light wave field rendering, by combining wave graphics, Fourier optics, computational holography and the existed image based rendering techniques. In light wave field rendering, a 3D wave field is represented by one or more wavefronts which are stored as 2D arrays of complex numbers.

本文结合波动图形学、计算全息学和傅立叶光学等研究领域的相关技术，将波动的概念引入光场绘制过程，根据定态光波场的解析特性，使用平面或封闭曲面波前上的二维复振幅分布，来表示无源空间中三维的光波场，提出了一种基于光波场的绘制技术，用于三维物体的视点无关绘制和立体真实再现。

More direct, directer ; most direct, directest

径直的，笔直的

Do you know how to use a chain saw?

你知道如何使用链锯吗？