【单选题】光强度与单色器狭缝宽度有关,定性分析时采用的宽度为()
【简答题】在宽度为a=0.60mm的狭缝后放置一焦距f=40cm的会聚透镜,若以单色平行光垂直照射狭缝,则在置于透镜主焦平面处的屏幕上x=1.4mm处的P点看到衍射明条纹,求 (1)入射光的波长以及P点衍射条纹的级数; (2)在该衍射条件下,缝面可分成的半波带数; (3)中央明条纹的宽度以及第二级明纹对应的衍射角。
【简答题】在单色器的线色散率为0.5mm/nm的条件下用原子吸收分析法测定铁时,要求通带宽度为0.1nm,狭缝宽度要调到______。
【单选题】Choose the best item to complete each of the following sentences. 7. He always ______ the latest fashions.
【单选题】Choose the best item to complete each of the following sentence. 7. Does art ______ society, or shape it?
【单选题】Choose the best item to complete each of the following sentences. 1、 There’s no supermarket in the _____ area.
【单选题】Choose the best item to complete each of the following sentences. 4. Wearing long skirts has become very ______ recently.
【判断题】夜郎文化是贵州最独特的历史文化,是贵州文化的源头,现代人既受夜郎文化的熏陶,也创造和发展了 “ 夜郎文化 ” 。
【单选题】Choose the best item to complete each of the following sentence. 6.This sentence doesn't make any______.