| 摘要 |
<p>Apparatus for generating acoustic fields in liquids, for example for removing particulate matter from water, has a thin metal plate (12) contacting the liquid and a thick metal plate (14) which is fixed. The two plates are connected as a capacitor with an air gap. The application of an r.f. voltage causes the thin plate, which is held at its margin, to vibrate so generating an acoustic field.</p> |
