查询词典 wave pattern

The transmit part adopts the phase-locked loop pattern of frequency synthesizing technology and uses the MC145152 and MC12022 chips to compose the phase-locked loop.It locks the frequency of the carrier-wave at 35MHz.The stabilization of the carrier-wave can be 4×10-5,the accuracy can be 3×10-5.The frequency modulation and the confection of the carrier-wave are realized by the capacity-changing diode V149 and the integration voltage-control oscillator MC1648 chip.The end power amplifier uses the audion 2SC1970 to make it work in the third magnifying state,it improves the efficiency of the magnifier and the power of the output reaches the design demand.

发射部分采用锁相环式频率合成器技术， MC145152和MC12022芯片组成锁相环，将载波频率精确锁定在35MHz，输出载波的稳定度达到4×10-5，准确度达到3×10-5，由变容二极管V149和集成压控振荡器芯片MC1648实现对载波的调频调制；末级功放选用三极管2SC1970，使其工作在丙类放大状态，提高了放大器的效率，输出功率达到设计要求。

1Niche construction can lead to stable coexistence of diverse genotypes in spatially structured population, which supports a stable polymorphism even without heterozygote superiority.(2)With habitat deterioration, niche construction accelerates the formation of steady polymorphism and hence impedes the harmful influences of environment on the population, which might embody a life-history strategy of organism under the unfavorable environment.(3)Niche construction results in the coexistence with alternative polymorphism through genotype-environment feedback and limited gene flow.(4)The niche-constructing organism is an active force to alter its environment and hence the direction of natural selection in order to better survival.(5)Spatial dynamics and distribution pattern of metapopulation are profoundly influenced by time-lagged niche construction.(6)Metapopulation size can reach a fixed level in the recency effect and equal weighting of time lag but is statistical stability in primacy effect, which implies the primacy effect is most remarkable.(7)The increment in the relative weightingof each generation\' niche construction and the length of time lag are significant factors for system destabilization.(8)Moderate capacity of positive niche construction benefits the metapopulation persistence.(9)The narrowing of niche breadth can decrease the metapopulation size and thereby increase the extinction risk.(10)The coupled function of time lag and niche construction make the system oscillation and generate the spiral wave, spiral-broken and circular wave in heterogeneous habitat.The spatial distributions of metapopulation and resource content are complementary due to a phase lag of their both frequencies.(12)Metapopulation persistence with niche construction depends not only on the balance between colonization and extinction, but also on the balance between the ability of niche construction and natural dissipation of habitat.(13)Metapopula-tion can survive under certain condition when the percent of suitable patches in habitat is lower than the ration of extinction to colonization.(14)Two thresholds exist in the process of transition of habitat quality dynamics from unsuitable to suitable, which include the intensity of niche construction and the initial condition of system.(15)Metapopulation size is positive correlated with the ability of positive niche construction, which means that organism or population who has strongly positive influences on their environment plays an important role to maintain the available habitat.

通过上述几个方面的研究，主要得出以下15条结论：(1)生态位构建可使空间结构种群，甚至是在没有杂合子优势的条件下，形成多种可能的稳定基因型分布模式；(2)随着环境的破坏与恶化，种群的生态位构建作用加速其较早形成稳定多态以阻碍环境对种群的不利影响，解释了有机体在不利环境下的一种生活史对策；(3)生态位构建作用通过基因型—环境反馈机制及有限的基因交流导致基因型多态的稳定共存；(4)有机体的生态位构建作用是一种积极的动力改变环境进而改变其自然选择的方向；(5)生态位构建的时滞作用对集合种群动态和空间分布产生深刻影响；(6)集合种群大小在时滞的崭新效应和等权重效应下达到一固定值，而在首位效应下达到统计稳定，表明首位效应的影响最显著；(7)首位效应下生态位构建相对权重的增量和时滞的长度是影响系统不稳定性动态的关键因素；(8)适中的生态位构建强度有利于集合种群的续存；(9)生态位宽度变窄会减少集合种群的数量从而增加其灭绝风险；(10)时滞和生态位构建的双重作用使系统产生周期振荡，并在异质性环境中产生稳定的螺旋波，破碎的螺旋波和环形波三种分布模式；(11)集合种群与资源含量的空间分布因为相滞而互补；(12)具有生态位构建的集合种群续存不仅取决于侵占率与灭绝率之间的平衡，而且依赖于生态位构建能力同其生境的自然消耗速率之间的妥协；(13)当生境中适合侵占的斑块比例小于其侵占率与灭绝率之比时，生态位构建作用促使集合种群在一定条件下续存：(14)生境斑块的状态从不适合到适合转变过程中存在生态位构建强度和系统初始条件这两个阈值；(15)集合种群的大小同正生态位构建能力正相关，意味着对环境具有较强正作用的有机体对维持有效生境起积极作用。

The key components in laser gyro is He-Ne ring laser, and the reciprocal action theory between light and medium is the base in studying the ring laser, use the Lamb half classical theory, and on the base of density matrix theory, the optical Brounch equation was established, which described the movement of amplifying medium atom in the ring syntonic cavity, and according to the medium polarize theory the self consistent equations was deduced, which describe the light intensity and phasic of the counter-propagating wave. On the basis of this equations, adopted the simulation software MATLAB and virtual instrument programming language LabWindows/CVI, we can do some simulated experiments in study the phenomenas such as amplify and dispersive characteristic of medium, mode pushing effection, burned hole effection and pattern competition, lock-in of frequency and the characteristic of light intensity and phasic of the counter-propagating wave in laser gyro.

激光陀螺的核心部件为He-Ne环形激光器，而掌握光与介质的相互作用理论是研究激光器的关键，采用拉姆半经典理论为主，在密度矩阵理论的基础上，推导环形谐振腔中描述He-Ne气体增益介质原子运动的光学布洛赫方程，运用介质极化理论得出描述激光陀螺反向行波的光强、位相所满足的自洽场方程组，在此基础上，运用MATLAB仿真软件和虚拟仪器编程语言LabWindows/CVI，对激光陀螺中的介质增益色散特性、频率牵引效应、烧孔效应及模竞争、闭锁效应及环激光的光强和相位特性进行仿真试验研究，并且运用全量子理论，对激光工作原理进行分析，得出二能级系统单模辐射场的光子数密度分布，得出激光场的光子统计分布，仿真激光场的动态建立过程。

One of the important tasks in my dissertation is to investigate Fraunhofer diffraction pattern of a polychromatic, spatially coherent wave diffracted by an annular aperture. The phenomena of spectral anomalies in the vicinity of the Airy rings in Fraunhofer diffraction pattern are investigated in detail. The effect of the parameters of the annular aperture on the spectral changes is studied particularly.

本学位论文的一部分内容进一步研究了在夫琅和费衍射模型下，多色空间相干光经过环形光阑衍射后的光谱变化情况，详细讨论了在该模型下振幅为零的点附近的光谱奇异现象，着重研究了改变环形光阑参数等对光谱变化的影响。

Ultrasonic is one of mechanical wave with wave frequency scope 20-106 KHz, Using Ultrasonic to accelerate or generate a new reaction is its new pattern arisen intercross course.

超声波是频率范围20-10~6KHz的机械波，利用超声波来加速或引发新的反应是一门新兴的交叉学科。

When the plane wave returns and crosses the molecule, it produces an interference pattern with the stationary part of the electron wave function, like two trains of water waves crossing and forming a checkerboard disturbance.

一旦平面波折返并横越过分子，它便会与待在轨道上的电子波产生干涉图样，就像是两道水波相遇所形成的西洋棋盘般明暗交错的扰动。

It is found that topological charge of vortex beam influences the interference pattern, i.e., by compared with the straight interference pattern of plane wave, the interference pattern of vortex beam is shifted in the transverse direction as we look from the top of the interference to the bottom, and the magnitude and direction of shift are related to the topological charge.

详细介绍了涡旋光束的拓扑荷数对干涉条纹分布的影响。发现同平面波的竖直干涉条纹相比较，涡旋光束的干涉条纹，从顶部向底部看去，沿着横向出现移动，并且移动的大小和方向与拓扑荷数的取值有关。

This text introduce a sort of new pattern soft switch PFC circuit .First, analyze the develop course of the on-off power supply. Second, relate the harm of humorous wave to the commonality electricity net. Third, present the topology and the principium chart of the soft switch PFC and analyze it .At last ,set the parameter and simulates the converter of with matlab simulation. more over ,get the hold of well voltage and current wave , minish the spoilage of the circuit, enhance the efficience of the circuit, meet the demand of the miniaturization and viridity.

本文引入了一种新型的软开关PFC电路，首先分析了开关电源的发展历程，然后讲了谐波给公共电网造成的危害，再给出了这种软开关PFC的电路拓扑及原理图并对其工作原理进行了分析，最后对其参数进行设置在MATLAB软件进行了仿真，并得到了良好的电压电流波形，而且减小了电路的损耗，提高了电路的效率，实现了小型化，绿色化的要求。

The result shows that' this method can effectively optimize the data-visiting pattern of filter wave processing so as to raise the speed of two-dimensional and three-dimentional picture's filter wave processing.

结果表明，此方法能有效地优化滤波处理的数据访问模式，从而使二维和三维图像滤波处理速度提高3至7倍。

In degraded PSM matching classification, errors modification method of degraded PSM is presented and the matching tensor of every canonical scattering centers is given. In Chapter 4, the theory of wideband millimeter-wave radar target identification is introduced. It is indicated that, for HR radar target identification, description of temoral relations among features and pattern recogntion adaptive to variation of target angles are of key importance. A rule-based pattern recogniton method of sequential reasoning is proposed, which uses a series of rules to describe relations of features variation caused by target angles variation and has the advantages of adaption to unrandom variation and false probability control in classification over traditional statistical pattern recognitiop method. Feature extraction is crucial step in target identification. In range profiles identification application, features are extracted by means of range domain pre-processing algorithm, spacial and amplitude visual computation directly from range profiles and transform algorithm based on range profiles. Visual or transformed features are either sufficiently convinced or necessarily convinced and both of them are effective and robust to range profiles identification.

在第四章，首先对宽带毫米波体制背景下目标识别方法的一些特点进行了阐述并指出，在毫米波雷达目标识别中，特征之间动态关系的描述以及能适应目标姿态角变化的模式识别方法的研究乃是要解决的关键问题；进而提出了一种基于规则库的序贯推理模式识别新方法，在这种方法的研究中，主要包括序贯推理规则库的规则排列与特征选用顺序以及规则库的收敛等问题；这种方法克服了传统的统计模式识别方法特征利用效率不高、难以适应特征值的非随机性变化的缺点，把姿态角变化所引起的特征的变化用一系列规则加以表示，其优点是能适应特征值的非随机性动态变化，并能控制分类过程中的差错概率α；特征抽取是目标识别中的关键步骤，在基于目标距离像的特征抽取方法研究中，提出了距离空间域的预处理算法、距离空间域与幅度域的直观特征抽取方法以及基于目标距离像变换分析的特征抽取方法。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。