propagation structure 中文意思是什麼

On the base, we designed the waveguides " structure and fabrication parameter. and in the design of symmetric y - branch of proton - exchange s ingle - y phase linbo3 modulaor, we used finite difference beam propagation method to analyze and compare the optical transmission loss of different s - bend y - branch

本文對質子交換linbo _ 3單y相位調制器的重要部件y分支進行了深入的研究，比較了不同s彎曲形式的y分支過渡長度與損耗的關系，並計算出間距250 m時的最小彎曲長度。

The most achievement is that we firstly obtain the analytic accurate solution of the modal fields of the waveguide structure and find some available character : ( 1 ) the different uniaxial crystal materials have the different propagation properties ; ( 2 ) when the optical axis of the crystal is on the plane that is made up of the normal direction of the waveguide plane and the propagation, there are te mode and tm mode in this special waveguide, but the principal mode is different of the character of the uniaxial crystal, the principal mode is the principal mode of te mode for the negative uniaxial crystal, but the one of tm mode for the positive uniaxial crystal ; ( 3 ) when the crystal optical - axis parallel to the waveguide plane, for the positive uniaxial crystal material, the principal mode of the waveguide is a te wave, which can be excited by the light at any frequency ; when the light frequency satisfies a single mode propagation condition, there will be only the principal mode propagating in the waveguide, otherwise some of the higher order modes can be excited, which are neither te modes, nor tm modes, but the hybrid guided modes

本文就是在此背景下，利用金屬波導和單軸晶體的一些特性，結合麥克斯韋方程組和波導的邊界條件，從三種不同的情況研究了光在對稱平面單軸晶體金屬波導（波導層是單軸晶體，兩個波導界面均為金屬）內的傳輸特性，其主要貢獻為，首次解析地得到了這種波導結構下模式場的精確解，並發現了一些有用的特性： （ 1 ）模式場的性質因單軸晶體的性質不同而異； （ 2 ）當單軸晶體光軸位於波導界面法方向與傳輸方向構成的平面內時，波導中傳輸te波和tm波，只不過其主模因單軸晶體的性質不同而異，當波導層介質為負單軸晶體時，波導主模是te波主模，而波導層介質為正單軸晶體時波導主模是tm波主模。 （ 3 ）當單軸晶體光軸位於波導面內時，對于正單軸晶體，波導的主模是橫電波te _ 0模，任何頻率的光波均可激勵該模式；當光波波長滿足一定條件時，波導內傳輸單模，否則，將激勵起高階模式，高階模即匪te波，也匪tm波，而是兩者耦合而成的混合模。

Because of its complexity, no analytic solution can be got. to better understand the propagation characteristics of the waveguide, it is necessary that analytic solution should be got for simpler structure. based on the background, in this paper, we discuss the propagation characteristic of ray in the planar symmetric metal - clad uniaxial waveguide ( the waveguide layer is uniaxial crystal

但是以前人們只局限於對非對稱金屬波導（即在各向異性介質波導層一面上鍍有金屬膜）的討論，由於其復雜性，他們沒有給出解析解，為了能更好的解析討論其傳輸特性，需要討論較簡單的波導結構。

The aesculus chinensis, euptelea pleiospermum, cercidiphyllum japonicum, taxus chinensis, picea brachytyla arid emmenopterys henryi oliv compose and stand structure of were studied, and the comparability matrix among those main woods distribution ere studied, and the protection propagation countermeasures were put forward, which are important for researching and protecting these rare woods in funiu mountain natural reserve

經調查，基本摸清了國家保護植物七葉樹林、領春木樹林、連香樹林、紅豆杉樹林、雲杉樹林、香果樹林6種珍稀樹種林分的組成與結構，研究了主要林分之間的相似性矩陣，同時提出了保護繁育對策，對開展研究和保護珍稀樹種具有重要意義。

Using the beam propagation method ( bpm ) simulation, we confirm that wide controllability of the branching ratio and low excess loss can be realized by this structure

用bpm方法模擬的結果表明，此結構實現了50 - 94的不對稱分支比，並且具有低的附加損耗的特點。

In order to utilize the frquency resource adequately and increase the capacity of mobile communication system, the wireless electric wave propagation of existing mobile system always adopts the microcell structure. forecasting the path loss characteristic of electric wave accurately can provide the necessary condition for the layout and design of wireless network, at the same time it is a precondition for the research on the microcell mobile system. the methods of forecasting of wireless electric wave propagation can divide into two parts : one is pluse and respond, that is establish the empirical model based on experimental and statistical data ; the other is ray tracing method, that is establish the deterministic model based on theoretical analyse. the paper discuss the characteristic of wireless signal electric wave transmition in symmetrical atmosphere of earth, and introduce the common path loss transmition model in land mobile communication system, also point out the localization of these models based on experiential methods

而精確預測無線電波傳播路徑損耗特性，則為合理的微蜂窩無線網路規劃、設計提供了必要條件，同時也是研究微蜂窩移動通信系統性能的前提。無線電波傳播預測的方法分為兩類：一是用沖激響應法，即根據實驗、統計所得數據建立經驗性傳播預測模型；另一種是用射線跟蹤方法，即依據理論分析來建立確定性的傳播預測模型。本文首先討論了在地球表面均勻大氣中的無線電波傳播的基本特性，介紹了陸地移動通信系統中常用的幾種電波傳播路徑損耗經驗性預測模型，並指出了這些經驗性傳播模型對于微蜂窩小區無線電波傳播特性研究的局限性。

Soil - structure dynamic interaction is the dynamic responding of soils, foundation and superstructures excited by wave propagation in soils and structure virtually and, dynamic analysis of soil - foundation interaction is the key problem in studying soil - structure interaction

土?結構動力相互作用的本質就是波動在結構地基系統內傳播時引起的結構和地基的動力反應問題。研究土?基礎結構的動力相互作用是分析土?結構動力相互作用的關鍵。

According to fractal propagation characteristics of fatigue crack, it defines structure fatigue fractal damage variables and sets up the structure fatigue damage fractal evolution mode which macro and micro are consistent

採用分形維數定義了結構疲勞分形損傷變量，根據疲勞裂紋的分形擴展特點，建立了宏細觀統一的結構疲勞損傷分形演化模型。

To find the failure propagation mechanism from the inherent topological structure of the complex electromechanical system, the topological structure statistical properties of the system were analyzed with small world net theory, and a failure propagation model based on the small world clustering was proposed

摘要為了從復雜機電系統自身固有的網路拓撲結構出發來研究故障的傳播機制，採用小世界網路理論分析方法，對系統網路拓撲結構統計特性進行分析，建立了基於小世界聚類特性的故障傳播模型。

And the no - isothermal structure can accelerate the breaking of gravity wave in mesospause, and the breaking of gravity wave is an important source of convection and small - scale waves. the propagation of gravity wave will affect the distribution of minor species. the breaking of gravity wave accelerates the downward transport of atomic oxygen, some smaller - scale structures appear on the horizontal distribution of atomic oxygen number density, and other chemical species are also affected due to the chemical reaction with atomic oxygen and the propagation of gravity wave

在重力波的傳播過程中，氫氧大氣成分的水平和垂直分佈均受到了不同程度的影響，以氧原子的響應最為明顯，而其中重力波破碎在氧原子水平分佈上的反應則是非線性重力波過程的一個重要表現；另外，分析顯示，重力波的非線性傳播對oh氣輝的峰值分佈由明顯影響，小尺度重力波的傳播有時會引起oh氣輝出現奇異的雙峰分佈，重力波的破碎現象也可以從對氣輝的觀測中反映應出來，這對利用氣輝觀測研究重力波傳播特性有非常重要的指示意義。

A three - tiered artificial neural network ( ann ) model with a feed - forward, back - propagation net - work structure was developed to forecast river flow in the manwan reservoir

摘要以雲南省漫灣水電站歷史徑流狀況為研究對象，運用三層前饋反向傳播神經網路模型對徑流進行中長期預報。

Based on the damage mechanics theory, during the freezing and thawing, the ct measurement technology is used to observe the water transference, ice formation, inner microdamage propagation principle and the corresponding damage structure variability

從細觀損傷力學理論出發，利用ct識別先進的試驗技術研究巖石在凍結融化過程中，水分的遷移，冰的形成，內部細觀損傷擴展機理及相應損傷結構的變化。

The finite difference beam propagation method ( fd - bpm ) can simulate the performance of the waveguide accurately. single mode rid waveguide structure parameters are derived by variational - effective index method ; fd - bpm and its transparent boundary condition ( tbc ) are concerned, and then the eim used to transfer a 3d waveguide to 2d waveguide is analyzed ; finally we summarize the characteristic of the y branch

本文先利用變分有效折射率法推導出滿足單模傳輸的脊形波導結構參數;接著介紹了有限差分束傳播法及求解的透明邊界條件，同時分析了將三維結構轉化為二維結構的有效折射率法，最後對y分支的特性進行了模擬。

Reaction dynamic process and structure forming process in self - propagation high - temperature synthesis of ti - c - fe system

體系自蔓延高溫合成的反應動力學過程和結構形成過程

Second, negative dispersion without absorption, which leads to superluminal light propagation, is achievable in the central resonance structure of the dispersion spectrum. the negative dispersion is slightly weakened as the spacings between dressed states increase

其次，在色散光譜的中心區域，呈現出無吸收負色散，這種效應能夠導致超光速傳播，但它隨著修飾態間距增加而減弱。

The effects of different geometric interfaces on waves propagation in anisotropic rocks were simulated. three structures, including the corner structure, the straight structure and the multi - stripe structure, were discussed

模擬了位於各向同性巖石中的爆炸點源產生的彈性波在具有規則幾何界面的巖石（角結構、平直界面結構以及多條紋結構）中的傳播。

Using the theories of probability, algebra and number theory comprehensively, we investigate a class of boolean functions with three - valued walsh spectrum in the first part of this dissertation : the properties of the extended semi - bent functions, which are constructed from any two bent functions, are studied, followed by the structure characteristics of the boolean functions satisfying propagation criterion with respect to all but two vectors ; the definition and cryptographic properties of k - order quasi - bent functions are proposed whose walsh spectrum takes on only three values. some sufficient and necessary conditions are offered to decide whether a boolean function is a k - order quasi - bent function ; a special method is presented to construct the k - order quasi - bent functions, whose cryptographic properties are explored by the matrix method, which is different from the method of walsh spectrum and that of autocorrelation of boolean functions ; the application of this kind of boolean functions in the fields of stream cipher, communications and block ciphers is discussed, which shows the great importance of the fc - order quasi - bent functions ; some methodology are proposed to construct the k - order quasi - bent functions, including the complete construction by using the characteristic matrices of boolean functions, and the recursive method by two known k - order quasi - bent functions we further extend our investigation to the ring zp, where p is a prime, and the similar results are presented as far as the p - valued quasi - generalized - bent functions are considered

本文首先綜合運用概率論、代數學、數論等基礎學科的理論知識，並以頻譜理論作為主要研究工具，對一類譜值分佈相對均勻的函數? ?廣半bent函數、 k階擬bent函數和p值k階擬廣義bent函數進行了系統、深入的研究，給出了廣半bent函數定義，並探討了廣半bent函數的密碼學性質；給出了k階擬bent函數和p值k階擬廣義bent函數的定義及等價判別條件；討論了k階擬bent函數和p值k階擬廣義bent函數與部分bent函數和p值廣義部分bent函數的關系，探討了它們的密碼學性質；給出了k階擬bent函數和p值k階擬廣義bent函數的典型構造方法，並將對k階擬bent函數的密碼性質的研究轉化到對一類特殊的矩陣的研究上；利用布爾函數的特徵矩陣原則上給出了k階擬bent函數的一種完全構造方法，還給出了從已有的p值k階擬廣義bent函數出發，遞歸構造變元個數更多的p值k階擬廣義bent函數的方法；初步探討了k階擬bent函數在序列密碼、分組密碼以及通信中的應用；給出了一類布爾函數walsh譜的分解式，並利用這類布爾函數的walsh譜分解式給出了一類近似穩定的布爾函數的構造，特殊情形下為k階擬bent函數；利用代數數論的知識考察了p值k階擬廣義bent函數的譜特徵，並給出了k階擬廣義bent函數與所有仿射函數的符合率特徵等等。

We have the following results through simulation and experiments : i ) turbulent structure constant of atmosphere decreases with altitude ; ii ) turbulence induced power scintillation decreases with the optical wavelength ; iii ) scintillation of space - to - ground optical propagation is smaller than that of horizontal optical propagation ; iv ) power scintillation of space - to - ground optical propagation increases with wavelength ; results above are accord with existent theory. what ' s more, the last result discovers a new rule

通過對數學模型和模擬結果的分析，得到以下結論： a ）大氣湍流結構常數隨海拔高度的增加而迅速減小； b ）由湍流引起的光功率閃爍與波長呈反比； c ）空-地激光通信的光功率閃爍小於地面水平傳輸的閃爍； d ）空-地激光通信的光功率閃爍與波長呈正比；上述結果與理論保持一致。

This course begins with the study of nerve cells which includes their structure, the propagation of nerve impulses and transfer of information between nerve cells, the effect of drugs on this process, and the development of nerve cells into the brain and spinal cord

本課程一開始將針對神經細胞介紹其構造，神經脈沖的傳遞，神經細胞間的訊息傳遞，藥物對訊息傳遞的影響，以及神經細胞在大腦及脊椎的發生學。

Abstract : the equivalent step planar wave - guide method is proposed to studythe propagation properties and design of diffused planar wave - guide. the model was established, and a set of simulation has been done, and a series of relationship curves among the parameters of wave - guide propagation, structure and technics are obtained. these curves are helpful to diffused planar wave - guide design and technical parameter selection

文摘:本文引入一種研究擴散光波導傳播特性及設計計算的新方法? ?等效階躍平板波導方法.建立了擴散平板光波導的等效階躍平板波導模型，進行了一系列的模擬計算，得出了一系列波導傳播參量、結構參量與工藝參量之間的關系曲線.這些曲線對于擴散平板光波導的設計計算、工藝參量選擇等具有重要指導意義