Supercritical fluid extraction(SFE) is a new subject of separation techniques and develops rapidly in recent years because of its advantages over conventional extraction methods.However,there are still some problems unsolved with it,such as high operation pressure,long extraction time,relatively low extraction yield etc.,so that it can not be used widely at factory scale.Since modifier,ultrasonic filed,electrical field etc. can enhance SFE process and be used to solve the problems mentioned above,they beco...