Because the molecules in liquids are so densely packed together , the average time between collisions is a picosecond or由于液体中的分子很密地积聚在一起，所以，两次碰撞之间的平均时间间隔只有一微微秒或者更短些。
Besides,we will continue strive for the higher fields of ultraviolet,femtosecond , picosecond laser and so on .Surely we另外，我们还将向紫外激光、飞秒及皮秒激光等高端领域不断进取，永保国内领先，争创世界一流。