平面波以不为零的角度θ由介质 1(折射率为 n ₁ )入射到介质 2(折射率为n ₂ )表面上,折射波为零的条件是( )。

在双缝干涉中，光的波长为600nm，双缝间距为0.2cm，双缝与屏的间距为300cm，在屏上形成的干涉图样的明纹间距为（）。

在杨氏双缝干涉实验中，若将整个装置放在水中，则（ ）。

如图,在双缝干涉实验中,若把一厚度为e、折射率为n的薄云母片覆盖在S1缝上,中央明条纹将向___移动;覆盖云母片后,两束相干光至原中央明纹O处的光程差为___。

A declaration made by the Master before a PRC Consul，giving particulars regarding heavy weather or other incidents which may have caused damage to the vessel or cargo，through no fault of the vessel，her officers，or crew is a(n)（）.

Every deliberate act of wrongdoing by the master or any of the crew against the ship or cargo，without the authorization or privity of the Shipowner or his agent，is（）.

（）, or drum is used for hauling in or letting out the wires or ropes which will fasten the ship to the shore.

A salvor may be（）the whole or part of the payment due under Salvage Convention to the extent that the salvage operations have become necessary or more difficult because of fault or neglect on his part or if the salvor has been guilty of fraud or other dishonest conduct.

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

双缝干涉和多缝干涉的干涉条纹的区别是什么？

在双缝干涉实验中, 两条缝的宽度原来是相等的, 若其中一缝的宽度略变宽, 则干涉条纹间距不变。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。