三个偏振片 P 1 , P 2 与 P 3 堆叠在一起, P 1 与 P 3 的偏振化方向相互垂直, P 2 与 P 1 的偏振化方向间的夹角为 30° .强度为 I 0 的自然光垂直入射于偏振片 P 1 ,并依次透过偏振片 P 1 、 P 2 与 P 3 ,则通过三个偏振片后的光强为 (A) I 0 / 4 . (B) 3 I 0 / 8 . (C) 3 I 0 / 32 . (D) I 0 / 16 .
【简答题】Now it is becoming more and more popular to chat over the Internet, because you can find it 小题1: _______ expensive to do that than to make a long distance call. This makes Internet chatting 小题2: _____...
【简答题】Complete the following passage by filling in each blank with one word that best fits the context. Now it is becoming more and more popular to chat over the Internet, because you can find it 小题1:______...