圓柱面源 的英文怎麼說
中文拼音 [yuánzhùmiànyuán]
圓柱面源
英文
cylindrical surface source-
Its fundamental is that the ray emitted from a focus ( front ) of elliptical will flock together on the other focus ( back ) by the reflection on the elliptical surface. we set a scatter aperture on the back focus
橢圓柱面的前焦線上是射線源，晶體固定在一個橢圓基底上，其表面構成一橢圓柱面， x射線經晶體衍射后會聚於後焦線上。The conformal microstrip antenna with some unique character has been applied in many fields, especialy on speedy objects. in this paper, an efficient fdtd algorithm is introduced to analyse the microstrip antenna. firstly, the fdtd formula in descartes coordinate system and in cylindrical coordinate system are obtained from the time _ dependent maxwell equations using the yee algorithm in a calculating region where the dielectric parameters are independent of time and space. the choice of the space discretization units and the time discretization interval are discussed which are decided by the accuracy and stability respectively. the shape and setup of the excitation source are discussed too. the excitation source is chosen to be gaussian pulse in shape. secondly, the mur ' s first - order and second - order boundary condition are deduced in cylindrical coordinate system. the methods of transforming radiation fields from near zone to far zone in the frequency domain and in the time domain are presented when fdtd is applied to analyse the characteristics of far zone. finally, three kinds of microstrip antennas are analysed. they are a slot antenna that lies on a plane ground of a microstrip, a slot antenna that lies on a cylindrical ground of a microstrip and a microstrip line _ fed aperture coupled stacked rectangular patch antenna in cylindrical coordinate system
本文從麥克斯韋旋度方程出發，建立了笛卡兒坐標下無源空間中均勻無耗媒質的fdtd基本方程和圓柱坐標下無源空間中均勻無耗媒質的fdtd基本方程，詳細討論了fdtd法計算中時間步長和空間步長的選取原則以及激勵源的類型和設置；推導了mur一階和二階邊界條件在圓柱坐標下的差分格式；給出了在用fdtd法計算天線的遠場輻射特性時必需採用的頻域和時域近場遠場變換技術；最後用fdtd法計算了平面微帶縫隙天線、柱面共形微帶縫隙天線和柱面共形微帶層疊天線的輸入阻抗和遠區輻射場，並分析了天線的一些參數的變化對天線輸入阻抗的影響，得出了一些有用的結論。Larger loading capacity under the same specification ; easily establishing lubricant oil film, smaller friction coefficient, higher transmission efficiency, saving energy ; highest accuracy up to grade 3 of din standard ; smoother functioning, lower noisiness and longer service life
平麵包絡環面蝸桿與普通圓柱蝸桿傳動相比具有更大的承載能力，易於建立動壓油膜摩擦系數小，傳動效率高節省能源具有可磨削性，能達到din標準三級，面粗糙度優于ra0 . 4而且具有運行平穩噪音低壽命長等優點。In order to verify the feasibility of the present method, chapter 3 takes the fluid flow of sphere, cylinder and the additive mass of two spheres as three examples, finishes the calculation by disposing the source or sink whose strength is expressed as the format of nurbs and emphatically the processing of the singular integral. it can be drawn from the comparison of the results of present method and the theoretical solution, i. e. a good precision can be gotten under a few collocation points with the method
為了考查本文方法的可行性，第3章以圓球體繞流、圓柱繞流以及兩個等圓球體在流場中的附加質量作為例子，通過在物體表面布置強度以非均勻有理b樣條表達的源匯和著重對奇異積分的處理后完成了相應的計算，從與理論解的比較可以看出本方法的優越：在數目很少的配置點下數值解可取得十分良好的精度。The solving steps are as follows : the field is divided into three regions by the cylindrical surface of the finite - length cylinder and the location of the delta - coils. because " the surface current source is placed at the interface, the non - homogenous restricted equation on the magnetic vector potential is transformed into the homogenous helmholtz equation. by using the method of separation of variables to solve equation and according to the interface conditions and the condition at infinity to determine the unknown constants, the expressions for the magnetic vector potential of the three regions are solved out
在求解過程中，假定放置式圓柱線圈是由無窮多個對稱圓環線圈密饒而成，首先求解含有有限長磁芯的通電對稱圓環線圈的電磁場：以有限長圓柱磁芯的側面和圓環線圈所在圓柱面為分界面將場域劃分為三個小區域，由於場源放置在內邊界面上，使得關于矢量磁位的非齊次約束方程轉化成齊次亥姆霍茲方程，利用分離變量法求解，根據分界面鄭州大學碩十研究生畢業論文摘要條件以及無限遠條件確定待定常數，從而得到各場區矢量磁位的表達式。分享友人