媒質變換 的英文怎麼說
中文拼音 [méizhíbiànhuàn]
媒質變換
英文
media conversion-
The new developments of htm station technique were introduced from the aspects such as changing the htm pipeline type in pet htm station, increasing the switch forms of steam atomization and compressed air atomization, increasing the steam generator, sending stripping tower off - gas to combination and using new material nd steel in air preheater
摘要從改變聚酯熱媒站的熱媒爐熱媒管線形式、增加蒸汽霧化與壓縮空氣霧化的切換形式、增加蒸汽發生器、汽提塔尾氣送燒、空氣預熱器採用新型材質nd鋼等方面介紹熱媒站技術的新發展。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。But the sound field generated by this kind of transducers in medium has s ome " congenital " shortcomings : there always exist zero areas in sound - axes of near - field however we change the frequencies and radii of transducers, so we need to look for better radiate transducers. in this dissertation, we design and make two kinds of radiate transducers : bunchiness control transducer with electric polarity division and gaussian transducer
然而，這種類型的換能器在媒質中產生的輻射聲場，有其「先天性」的不足之處，在近場中無論平面活塞的頻率和半徑如何變化，軸上和沿徑向上都呈現出極大和極小交替分佈的干涉現象，因此我們有必要繼續尋求更為理想的輻射形式。Image compression plays an important role in transmission and storage of multimedia. wavelet has been widely adopted in image compression due to its multiresolution, time / frequency localization, lower time complexity, etc. with the advance of image compression techniques based on wavelet, a variety wavelet coefficient models are presented, such as ezw, spiht and ebcot used in jpeg2000
圖像壓縮在多媒體存儲和傳輸中扮演十分重要的角色，小波變換因具有時域頻域局部性、多分辨等性質在圖像壓縮中正在逐步取代dct變換，並已得到廣泛的應用。分享友人