一聚焦 与光学的聚焦相类似,在聚焦过程中可在焦点使声能达到极大值。一般情况下,焦点的位置与会聚镜镜面的曲率中心相重合。在声聚焦时,声压p、质点振动速度v和声强I都达到极大。聚焦系统可分为主动式与被动式两种。主动式是指具有弯曲辐射表面的超声发射器,直接产生会聚声场; A focus similar to optical focus, focus can be achieved in the focus to maximize the sound energy. In general, the focal point coincides with the center of curvature of the condenser mirror. In focus, the sound pressure p, particle vibration velocity v and sound intensity I have reached great. Focusing system can be divided into active and passive two. Active refers to an ultrasonic transmitter with a curved radiating surface that directly produces a converging acoustic field;