beam n. 1.梁,棟梁,桁條;(船的)橫梁。 2.船幅;(動(dòng)物、人的)體幅。 3.(秤)桿,杠桿,(織機(jī)的)卷軸,經(jīng)軸;(鹿角的)主干;車轅;犁柄;鋤把。 4.(光線的)束,道,柱;【物理學(xué)】波束,射束。 5.(笑容、表情等的)煥現(xiàn)。 6.【無線電】有效播聽范圍。 7.【航空】信號(hào)電波,指向電波。 a beam of light 一束光線。 the common beam 標(biāo)準(zhǔn)秤;準(zhǔn)則。 beam and scales 天平。 a beam of delight 高興的表情,笑逐顏開。 an erector beam 【火箭】(發(fā)射時(shí)調(diào)整導(dǎo)彈位置的)千斤頂。 radio beam 無線電領(lǐng)航信號(hào)。 a landing beam 【航空】降落指示波。 abaft the beam = before the beam. a beam in one's eye 自己本身的大缺點(diǎn)〔與他人目中之刺相比,自己眼中有梁,源出《圣經(jīng)》馬太福音〕。 before the beam 【航?!空龣M前。 broad in the beam 〔口語〕臀部闊大。 fly the beam 【航空】按指向電波飛行。 fly the wet beam 【航空】順著河流飛行。 kick [strike] the beam 1. (秤一方)翹起;過輕,不足抗衡,無足輕重。 2. 輸,遭受失敗。 off the beam 脫離航向,不順利;不對(duì)頭;做錯(cuò)。 on the beam 1. 【航海】與龍骨垂直地,正橫地。 2. 在航向上;對(duì)頭,做對(duì)。 on the port [larboard] beam 【航?!孔笙险龣M前。 on the starboard beam 【航海】右舷正橫前。 on the weather beam 【航海】迎著正橫風(fēng)。 ride the beam = fly the beam. vi. 1.輻射,發(fā)光,閃光。 2.微笑,眉開眼笑。 vt. 1.發(fā)射(光線、電波)。 2.向…放[播]送。 3.(用雷達(dá))探測(cè)。 4.(用波束)導(dǎo)航(飛機(jī)等)。 beam the program at America 向美國(guó)播送節(jié)目。 the sun beaming overhead 紅日當(dāng)頭照。 beam upon 看著…微笑。 beam with joy 眉飛色舞,笑逐顏開。
The beam orbit offset effects caused by the initial beam offset and linac componets " offsets in beam transferring process 良好的束流軌道可以獲得低發(fā)射度、低能散的高品質(zhì)束流。
The propagation of ultrashort laser pulse in air is analyzed with mechanics analogy by considering kerr effects and free electron defocusing . the equation describing the evolution of the laser spot is derived . it is shown that long distance focusing requires large initial beam and the propagation distance is very sensitive to the initial divergence angle of the laser beam 考慮多光子電離效應(yīng)和光學(xué)kerr效應(yīng),首次利用力學(xué)類比的方法研究了超短脈沖激光在電離氣體中的傳輸,詳細(xì)分析了傳輸距離與激光初始光斑、初始發(fā)散角以及激光功率的關(guān)系,提出了實(shí)現(xiàn)長(zhǎng)距離傳輸?shù)臈l件。
We discuss the effect on the focusing of the probe beams for the five initial parameters : the amplitude of the pump beam , the separation between the pump and the probe beam centers , the wavelength ratio of the pump and the probe beams and the ratio of the initial beam widths at the directions of x and y . our numerical results show that , more the amplitude of the pump beam , the wavelength ratio of the pump and the probe beams and the ratio of the initial beam widths at the direction of y , more the probe focus ; the separation between the pump and the probe beam centers and the ratio of the initial beam widths at the direction of x have optimum values , respectively 研究了泵浦光束輸入振幅、泵浦光束-信號(hào)光束初始偏移、泵浦光束-信號(hào)光束波長(zhǎng)比和泵浦光束-信號(hào)光束x 、 y方向的初始束寬比五個(gè)參量對(duì)信號(hào)光束聚焦程度的影響。數(shù)值模擬結(jié)果表明,泵浦光束輸入振幅越大、泵浦光束-信號(hào)光束波長(zhǎng)比越大、 y方向束寬比越大,信號(hào)光束聚焦程度越大;泵浦光束-信號(hào)光束初始偏移和x方向初始束寬比都存在一個(gè)最佳值,使得光束聚焦達(dá)到最佳效果,有趣的是這兩個(gè)最佳值的比值基本保持不變約為0 . 4 0 . 6 。
Secondly , the beam orbit offset effects caused by the initial beam offset and the linac components " offsets have been quantitatively studied first . as an example with the injector linac for beijing electron positron collider upgrading project ( bepcii ) , the beam orbit offset caused by the above error effects have been simulated and analyzed 其次定量研究束流的初始徑向誤差和加速器部件的安裝誤差等對(duì)束流軌道偏軸的影響,并以北京正負(fù)電子對(duì)撞機(jī)二期工程( bepc )的直線加速器為例,給出了上述各種誤差導(dǎo)致軌道偏軸的模擬計(jì)算結(jié)果及其分析。