length n. 1.長,長度,長短。 2.(時(shí)間的)長短,期間。 3.(賽艇的)一艇的長度;一馬的長度。 4.程度,范圍。 5.【板球】球程;投至適當(dāng)距離的球。 6.【語言學(xué)】音長。 7.一段,一節(jié)。 a dress length, a length of cloth 一段料。 a length of pipe [tubing] 一節(jié)管子。 The boat won by three lengths. 這只艇以三艇長之差得勝。 a (good) length ball 球程準(zhǔn)確的球。 at arm's length 在手臂伸得到的地方,疏遠(yuǎn) (keep sb. at arm's length 不與接近,敬而遠(yuǎn)之)。 at full length 1. 冗長地;充分地,詳細(xì)地 (give all the facts at full length 提供詳細(xì)的材料)。 2. 全身平伸地 (lie at full length 挺直身體躺著)。 at great length 冗長地,??唆唆地。 at length 1. 最后,終于,好容易才。 2. 充分地,詳細(xì)地 (speak at great length 詳細(xì)講了好久)。 at some length 相當(dāng)詳盡地。 cannot see beyond the length of one's nose 鼠目寸光。 draw out to a great length 拖得很久,占去很長時(shí)間。 fall [measure] all one's length 直挺挺地倒下。 find [get, have, know] the length of sb.'s foot 了解某人的弱點(diǎn)。 go (to) all lengths [any length] = go to great lengths 什么事都做得出;不遺余力。 go (to) the length of (doing) 甚至于,不惜。 go the whole length of it. 徹底干;干到底。 length of (sb.'s) days [life] 某人的壽命。 measure one's (own) length 跌倒在地。 of some length 相當(dāng)長。 over [through] the length and breadth of 到處,四面八方。 work at arm's length 在不利的條件下工作。
At present greco is regarded as one of the most valuable methods of radar cross section ( rcs ) computation in the high - frequency region . depending on these conditions , several researches have been completed in this paper : firstly , calculating rcs of complex conducting targets has been accomplished by greco method . the high - frequency rcs of targets are obtained through physical optics ( po ) and incremental length diffraction coefficients ( ildc ) respectively 本論文做了以下研究工作:首先,實(shí)現(xiàn)了運(yùn)用greco方法計(jì)算了高頻區(qū)理想導(dǎo)體復(fù)雜目標(biāo)的雷達(dá)散射截面( rcs ) ,分別應(yīng)用了物理光學(xué)法( po )和增量長度繞射系數(shù)法( ildc )計(jì)算了目標(biāo)的面元和棱邊的電磁散射,最后綜合面元與棱邊的散射效應(yīng)得到目標(biāo)的總rcs 。
Incremental length diffraction coefficients ( ildc ) is adopted to calculate the contribution of edge diffraction . in order to improve the accuracy of calculation , multi - scattering is discussed , based on the two former contributions and ray - tracing method . geometrical optics ( go ) and physical optics ( po ) are used to calculate the multi - reflection between facets and facets 對于鏡面反射采用物理光學(xué)法計(jì)算其散射貢獻(xiàn),結(jié)合基于面元的目標(biāo)模型的表示,采用離散的積分形式,將面電流積分化簡為線積分,簡化計(jì)算復(fù)雜度;對于邊緣繞射,運(yùn)用增量長度繞射系數(shù)理論計(jì)算目標(biāo)邊緣繞射場;在多次反射中,則以光線跟蹤方法為基礎(chǔ),采用幾何光學(xué)、物理光學(xué)相結(jié)合的方法分析考慮多次散射場。