ACOUSTIC CAVITATION GENERATED BY MICROSECOND PULSES OF ULTRASOUND
ACOUSTIC CAVITATION GENERATED BY MICROSECOND PULSES OF ULTRASOUND
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DOI：
10.1038/319052a0
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发表时间：
1986-01-02
期刊：
影响因子：
64.8
通讯作者：
FOWLKES, JB
中科院分区：
文献类型：
--
作者：
CRUM, LA;FOWLKES, JB
在极端的声应力下，液体会破裂，并瞬间产生一个蒸汽腔。这些空洞随后的坍塌通常是剧烈的，足以用肉眼或肉眼观察到，并且由于与坍塌相关的高温和高压，通常会产生自由基。flynn1计算出峰值强度在10-30 W cm−2范围内的微秒级超声脉冲可以在水中产生瞬态空化。由于目前临床上使用的一些诊断超声系统产生的脉冲长度为微秒，其时间峰值强度为100 W cm−2，因此有理由相信该机制可以在水介质的诊断条件下运行。我们在这里表明，在1.0 MHz频率下，短于一个周期的超声波脉冲会产生具有强烈空化特征的发光闪光。这为弗林的理论计算提供了第一个实验证实。
Under extreme acoustic stress, liquids can be caused to rupture, with the transient generation of a vapour cavity. The subsequent collapse of these cavities is normally violent enough to be observed with the unaided eye or ear, and often generates free radicals due to the high temperatures and pressures associated with the collapse. Flynn1has calculated that microsecond pulses of ultrasound with peak intensities in the range 10–30 W cm−2can generate transient cavitation in water. Because some diagnostic ultrasound systems2,3now in clinical use generate microsecond length pulses with temporal peak intensities >100 W cm−2, there is reason to believe that this mechanism could operate in diagnostic conditions in aqueous media. We show here that ultrasonic pulses as short as one cycle at a frequency of 1.0 MHz give rise to luminescence flashes characteristic of violent cavitation. This provides the first experimental confirmation of Flynn's theoretical calculations.