一、概述超声波振蕩是机械能中的一种。它可以在气态介质、液态介质或者固态介质中传播,并具有听觉以外的頻率(即高于16,000赫芝)。超声波可以用一定的仪器来造成,这种仪器依借其它来源的能量发出超声波的振蕩。 1880年Galton发明的气体哨笛,是历史上記載可查的最早的超声发生器。以后Hartmann等又在此基础上作了改进,制造能产生更高频率的超声发生器。随着科学的发展,继之又出現了用压电換能器和磁致伸縮換能器来产生高頻率超声波。在药物萃取上所用超声波的来源,以获自 I. Overview Ultrasonic vibration is one of the mechanical energy. It can spread in gaseous, liquid or solid media and has a frequency other than hearing (ie, higher than 16,000 Hertz). Ultrasound can be created with certain instruments that oscillate ultrasonic waves using energy from other sources. The gas whistle invented by Galton in 1880 was the earliest recorded ultrasonic generator in history. Later, Hartmann et al. also made improvements on this basis, creating ultrasonic generators that generate higher frequencies. With the development of science, piezoelectric transducers and magnetostrictive transducers have emerged to generate high-frequency ultrasonic waves. Source of ultrasound used in drug extraction to obtain