【简答题】某同学测量玻璃砖的折射率 ,准备了下列器材:激光笔、直尺、刻度尺、一面镀有反射膜的平行玻璃砖.如图所示,直尺与玻璃砖平行放置,激光笔发出的一束激光从直尺上O点射向玻璃砖表面,在直尺上观察到A,B两个光点,读出OA间的距离为20.00 cm,AB间的距离为6.00 cm,测得图中直尺到玻璃砖上表面距离d 1 =10.00 cm,玻璃砖厚度d 2 =4.00 cm.则玻璃的折射率n= ,光在玻璃中传播...
【单选题】An inert gas system is designed to reduce the possibility of tank explosions by().
A.
eliminating sparks and fire in the vicinity of cargo tanks
B.
removing all hydrocarbon gases from the cargo tanks
C.
blanketing cargo tanks with inert foam
D.
reducing the oxygen concentration below levels necessary for combustion
【单选题】两种单色光由玻璃射向空气时发生了全反射 , 临界角分别为 1 、 2 , 且 1 > 2 . 1 n 、 2 n 分别表示玻璃对这两种单色光的折射率 , 1 v 、 2 v 分别表示这两种单色光在玻璃中的传播速度 , 两种单色光由玻璃射向空气时发生了全反射 , 临界角分别为 1 、 2 , 且 1 > 2 . 1 n 、 2 n 分别表示玻璃对这两种单色光的折射率 ...
【单选题】在玻璃(折射率n 3 =1.60)表面镀一层MgF 2 (折射率n 2 =1.38)薄膜作为增透膜.为了使波长为λ的光从空气(n 1 =1.00)正入射时尽可能少反射,MgF 2 薄膜的最少厚度应是:
【单选题】The fresh air intake of the inert gas system().
A.
prevents the flue gas from falling below 3% content of oxygen
B.
allows the inert gas piping to be used for gas freeing the tanks
C.
opens when there is excessive vacuum on the deck water seal
D.
enables outside air to mix with and cool hot flue gasses
【单选题】. 在玻璃 ( 折射率 n 2 = 1.60) 表面镀一层 MgF 2 ( 折射率 n 2 = 1.38) 薄膜作为增透膜.为了使波长为 500 nm(1nm=10 9 m) 的光从空气 ( n 1 = 1.00) 正入射时尽可能少反射, MgF 2 薄膜的最少厚度应是
【单选题】The deck water seal of the inert gas system().
A.
cools the inert gas and prevents soot from entering the cargo tanks
B.
acts as an emergency system shutdown when the inlet pressures exceed the safe working pressure in the hazardous zone
C.
prevents the backflow of hydrocarbon gasses into nonhazardous areas
D.
relieves sudden large overpressures in the system
【单选题】在玻璃(折射率n2=1.60)表面镀一层MgF2 (折射率n2=1.38)薄膜作为增透膜.为了使波长为500 nm的光从空气(n1=1.00)正入射时尽可能少反射,MgF2薄膜的最少厚度应是
【单选题】在玻璃 ( 折射率 n 3 = 1.60) 表面镀一层 MgF 2 ( 折射率 n 2 = 1.38) 薄膜作为增透膜.为了使波长为 500 nm 的光从空气 ( n 1 = 1.00) 正入射时尽可能少反射, MgF 2 薄膜的最小厚度应是