查询词典 frequency analysis

The time-domain response of the induced currents on a scattering object irradiated by a plane wave with a Gaussian pulse in time is expanded as an associate Hermite series in this paper. Using the isomorphism of the associate Hermite function and its Fourier transform, the frequency-domain information can be obtained similarly to the time-domain expansion. According to the corresponding relation between time-domain analysis and frequency-domain analysis, and using the early-time response and the low-frequency information of the induced currents, the non-known coefficients in the expansion series can be decided. The entire responses of the induced currents on the scattering object in both time and frequency domains can be obtained at one time by simultaneous extrapolation computation using both the early-time response and the low-frequency information of the induced currents.

摘要首先根据散射体在高斯脉冲平面波激励下感应电流的能量几乎全部集中在时间轴和频率轴上的有限范围内，该文将时域响应展开为系数待定的连带Hermite级数的叠加，并根据连带Hermite函数的傅里叶变换的自反性，得到与时域响应形式类似的频域响应；然后利用时域方法和频域方法分别计算散射体上感应电流的早时响应和低频信息；最后经过时域和频域联合外推计算，由早时响应和低频信息确定时域和频域响应的待定系数，从而获得了整个时域和频域的完全响应。

A detailed analysis of the main circuit introduction, control method and working principle of the direct-drive wind energy conversion system are given to introduce the two important parts a of this paper: First part is the control method of the multiple boost convertor, the important instantaneous current control method of this paper is given through the analysis of the main circuit structure, control method and working principle. Then a steady-state analysis for low-frequency, a high-frequency component analysis, and a closed-loop tracking performance analysis for dynamic response are provided to analyze the method proposed; And the second part is the control method of invertor.

在系统变流器整体结构分析的基础上，引出本文重点研究的两个变流环节的控制：第一部分是系统升压斩波器的控制，通过分析相关主电路结构、原理，建立了数学模型，引出本文重点研究的瞬时值控制策略的概念和具体实现，并对升压斩波器的瞬时值控制策略进行了详细的高频、低频模型分析和稳态、动态性能分析；第二部分是系统并网逆变器的控制，通过对逆变器主电路的数学建模和控制要求分析，研究了并网逆变器的瞬时值控制策略，包括电感电流控制内环和直流电压控制外环的具体设计和实现方法。

Chapter one is "Introduction". On the basis of summarizing the history of the study of the pictophonetic characters, we suppose some theoretical principle, such as the principle of the correspondence between the form and the meaning of the individual graph of Chinese characters, the principle of the total graphs of Chinese characters being a character-formation system, and the principle of the optimum development of the character -formation system in the history, and som analytic methods, such as the methods of structrue-function analysis, form-position analysis and meaning factor analysis, in the study of the pictophonetic characters. Chapter two is titled"General knwledge of the pictophonetic character." We discuss their origins, nature and some standards of distingnishing them, introduce the knowledge about the editions of SHUO WEN JIE ZI, analyse the functions of the modules of pictophonetic characters in detail, discuss concretely the function of phonetic graphs showing origins and pronunciations, the function of meaning graphs showing meanings and analogies, and the function of distinguishment when the two kinds of graphs are conbined. Chapter three is"The system of meaning graphs of Xiao Zhuan system."After we describe the structure of the meaning graph system, the relations between meaning graphs, the distributions of the function of meaning graphs showing meanings, and the frequency of all this kind of graphs, we get a table of all meaning graphs, a table of the frequency. Chapter four is"The system of phonetic graphs of Xiao Zhuan system."We describe the structure of the phonetic graph system, the relations between phonetic graphs, and between their function showing origins and their function showing pronunciations, and their frequency, then we get ageneral table of phonetic graphs and table of their frequency. Chapter five is "conclusion". We think that systematical methodology is useful in describing and analysing the formation system of Chinese characters. The methodology is adaptable in describing the formation system of modern Chinese characters as well as the historical character systems, adaptable in describing horizontally as well as comparing vertically. Only when we finish the systematical vertical compare on the base of systematical horizontal decription, could we know the true history of the system of Chinese characters, recover the rule of the system's development, and supply the theoretical supports for the scientifical arrangement of modern Chinese characters.

第一部分—绪论，在总结形声字研究历史状况的基础上，提出了研究形声系统的理论原则和分析方法，即汉字个体字符形义统一的思想，汉字字符集合构形系统的思想，汉字构形系统历史演变系统优化的思想等三项理论原则和结构功能分析法，形位分析法，义素分析法等三种分析方法，还扼要地介绍了具体的工作程序和论文的主要内容；第二部分—形声字概述，论述了形声字的来源、性质和鉴别标准，介绍了对《说文解字》正篆形声字说解中的传抄讹误，版本异文，说解错误校勘和考证的经过，详细分析了形声字构件的功能，具体讨论了声符的示源功能与示音功能，义符的示意功能与类化功能以及声符与义符组合中的相互区别功能；第三部分—小篆字系的义符系统，从义符系统的构成、义符间的相互关系，义符示意功能的分布及义符的构字频度等不同侧面，对义符系统进行了全面的描写，产生了义符总表、义符间意义关系总表和义符构字频度总表；第四部分—小篆字系形声字的声符系统，从声符系统的构成、声符间的相互关系，声符的示源功能与示音功能的关系以及声符的构字频度等不同侧面，对声符系统进行了全面描写，产生了声符总表和声符构字频度总表；第五部分—结束语，在全面测查小篆字系形声字的基础上，对研究汉字的方法和现代汉字发展方向的问题提出了一些看法，认为系统论的方法是描写和分析汉字构形系统行之有效的方法，系统论方法，不仅适用于历史上文字系统的描写，也适用于现代汉字构形系统的描写，不仅适用了断代描写，也适用于历史比较，只有在对汉字断代系统描写的基础上进行系统的历史比较，才能认清汉字系统历史演变的真相，揭示汉字系统发展的客观规律，为科学地整理现代汉字提供理论上的依据。

In the part of the vibration experiments and analysis, firstly, used the simple-beam theory to estimate the natural frequency of the beam of the 20-headed computerized embroidery machine.secondly, measured the beam of its low rank natural frequency, the beams horizontal vibrating acceleration amplitude, speed amplitude and the displacement amplitude in different rev and different turn parts. Found that it is sympathetic vibration, which bring on the thread-broken rate rise rapidly. On this base, established the finite element analysis modle of the vibrating beam, and took on hamonic analysis and modal analysis with the mold. The rusult of test and analysis offer the basis for farther improvement of the computerized embroidery machine.

振动分析部分，首先由简单梁理论出发，对横梁的固有频率进行估算；接着通过测振仪器对20头电脑刺绣机横梁进行了试验模态分析和不同工况振动测试；获得了横梁前四阶固有频率和模态振型，以及在不同工作转速、不同回转部件下横梁振动的加速度幅值、速度幅值和位移幅值；找到了横梁振动加剧的原因——共振；在此基础上建立了符合实际情况的横梁有限元模型，对模型进行了模态和谐响应计算，证实了模型的可靠性，为下一步的改进设计提供了依据。

Secondly, the paper has carried on the analysis to the millimeter wave blasting fuse near field target characteristic, and has produced a RCS measuring technique. The analysis is that non- atmosphere window triangle wave modulation millimeter wave blasting fuse slip frequency spectrum, which has completed under the triangle wave modulation slip frequency signal time domain and the frequency range analysis.

随后对毫米波引信近场目标特性进行了分析，并给出了一种RCS的测量方法，并系统分析了非大气窗口三角波调制毫米波引信的差频频谱，完成了三角波调制下的差频信号时域和频域分析。

This system ofcompatible electromagnetism of frequency spectrum has someimportant functions listed as follows:(1) Analysis disturbance of the same or adjacent frequencies (2) Analysis of performance of radio link (3) Analysis of intermodulation (4) Automatic selection of frequency(auxiliary assignment of frequency)(5) Prediction of region of radio field intensity (6) Harmonization of frequency border (7) Analysis and design the system of microwave and satellite earth station.(8) Generate photographs This paper realizes the function of harmonization analysis ofthe system of microwave and satellite earth station. The concretework includes:(1) Based on the propagation model of radio wave,computing the absorption loss of atmosphere of microwavecommunication system and its fading, simulating the receivingvoltage and realizing the computation of disturbance andharmonization between microwave station and earth station.

频谱电磁兼容分析系统主要实现以下几个功能：⑴同、邻频干扰分析⑵无线链路性能分析⑶互调分析⑷频率自动选择⑸场强覆盖预测⑹边界协调⑺微波与卫星地球站系统设计和干扰协调分析⑻图形制作功能本文做为全省建设的电磁兼容分析系统的一部分，实现了微波站与地球站干扰协调分析这一功能，具体有：⑴以无线电波自由空间传播为模型，对微波通信系统的大气吸收损耗和衰落储备量进行了计算、对接收电平进行了模拟仿真，实现了微波- I -吉林大学硕士学位论文 Abstract站与地球站之间的干扰与协调计算。

With other books on the subject either limited in scope or seriously outdated, Flood Frequency Analysis provides the ideal vehicle for practicing hydrologists and engineers to explore and apply the latest methods and research results, and in doing so, contribute to the advancement of the field.

因为其他书在学科上既没在或者严重过时的范围限制，洪水频率分析为培训水文工作者和工程师探索并且使用最新的方法和研究结果提供理想的车辆，并且在此过程中，有助于领域的改进。

The principle of laser interferometric imaging is clarified with the theory of frequency analysis.

以频域分析的方式对激光干涉条纹成像原理进行了阐述

Using Matlab language of the wavelet transform procedure is time-frequency analysis of a kind in the time domain and freq...

这是一个用matlab语言编写的小波变换的程序，是时频分析的一种，可以在时域和频域内对信号进行分析。

Using tools from dynamical system theory, such as phase space diagrams, Frequency analysis, Poincare sections and the calculation of statistical quantity of chaos: the correlation dimension, Reni entropy, Laypunov exponent and so on, the different solutions to the Navier-Stokes equations at different values of the Reynolds number have been identified and characterized through reconstructing the phase space of velocity time series by means of time delay and dimension embeding.

通过时间延迟和维数的嵌入对速度时间序列重构相空间，利用非线性动力系统理论方法诸如相空间分析，频谱分析，Poincare映射，以及通过对混沌统计量：关联维数，Reni熵，Laypunov指数等计算，对不同雷诺数N-S方程解的特征作了分辨。

Since historical times,England ,where the early inhabitants were Celts, has been conquered three times .

从有历史以来，英国，在此地早期居住的是凯尔特人，已经被征服了三次。

Bluetooth OBEX File Transfer Enables the sending and receiving of files on your phone via Bluetooth.

蓝牙OBEX文件移动允许经过蓝牙传送和接受文件。。。。