Williams A R, Miller D L
Department of Medical Biophysics, University of Manchester Medical School, UK.
Phys Med Biol. 1989 Nov;34(11):1561-9. doi: 10.1088/0031-9155/34/11/005.
It is well known that a liquid exposed to relatively low intensities of MHz ultrasound may or may not cavitate depending upon a variety of non-acoustic factors. This paper shows that in some cases the material used as the acoustically transparent window and even the length of the sample chamber may also be important factors. Cling film, dialysis membrane and Parafilm are all equally acceptable as acoustically transparent windows for ultrasound, whereas glass cover slips or 'soft' surfaces (in which active bubbles may embed themselves) are not. All the results obtained confirm the validity of bubble recycling as being the dominant mechanism responsible for the enhancement of cavitational activity commonly observed when the sample chamber is rotated.
众所周知，暴露于相对低强度兆赫兹超声下的液体可能会发生空化，也可能不会，这取决于多种非声学因素。本文表明，在某些情况下，用作声学透明窗口的材料甚至样品腔的长度也可能是重要因素。保鲜膜、透析膜和石蜡膜作为超声的声学透明窗口都是同样可接受的，而玻璃盖玻片或“软”表面（活性气泡可能嵌入其中）则不行。所有获得的结果都证实了气泡循环作为主要机制的有效性，该机制是样品腔旋转时通常观察到的空化活性增强的原因。
