rarefaction wave短语¹⁸⁰⁰⁹⁸⁺¹ 基本例句 稀薄波,稀疏波 The intensity and the diameter of the laser spot are different at the different defocusing distance, so the rarefaction wave effect and the plasma shielding effect are different too. 离焦量不同时，由于作用激光的功率密度不同而影响等离子体屏蔽效果； cnki