【单选题】波长为0.168nm(1nm=10-9m)的X射线以入射角θ射向某晶体表面时,在反射方向出现第一级极大,已知晶体的晶格常数为0.168nm,则θ角为( )。
【简答题】What is the speaker's main topic? [A] Training for a professional athlete. [B] His physical training. [C] How to do cross-country running. [D] How to do mountain climbing.
【简答题】Bao Company has a defined benefit plan for its employees.Which of the following changes in assumptions would most likely decrease its reported pension expense? An increase in the expected: A.retiremen...
【判断题】现在流行歌曲的题材非常窄,基本上都是爱情。( )
【判断题】某单色 X 射线以 30° 角掠射晶体表面时,在反射方向出现第一级极大;而另一单色 X 射线,波长为 0.097 nm ,它在与晶体表面掠射角为 60° 时,出现第三级极大.则第一束 X 射线的波长为 0.168nm . (1 nm = 10 -9 m)
【简答题】It took to get to the sea by car from Chang Weng’s company or office.
【单选题】What is the speaker's main topic?
A.
Training for a professional athlete.
B.
His ways of physical training.
C.
How to do cross country running.
D.
How to do mountain climbing.