摘要或動機

聲致發光效應(sonoluminesence)為最近二十年來相當新穎的研究領域，其基本原理是利用超聲波將水中的氣泡集中，並使之隨著超聲波快速且連續的膨脹壓縮，當氣泡被壓縮至最小時溫度急遽上升，並放出藍白色的光芒。正因為這是一個嶄新的領域，所以許多實驗是以嘗試錯誤的方法去進行，但也因此發現了一些特殊的現象：1. 氣泡在正常的頻率(30kHz)以外，經過一段不可發光的頻率後，還可在更高頻率(接近40kHz)的地方發光2. 氣泡發光效率曲線在不同性質溶液中的差異3. 針對高頻率發光及雙泡發光的部分，做了兩個相關的假設並進一步驗證，得到了相當特別的結論。至今已有許多關於此研究的成果發表，但對於同時兩顆氣泡存在並發光的雙泡發光現象(double-bubble sonoluminesence)卻還很少人研究。因此我們嘗試較系統化地分析雙泡發光，期望能夠對這個現象有進一步的認識，並對日後的多泡發光(muti-bubble sonoluninesence)研究奠定基礎。Sonoluminescence has been a very popular topic for the past twenty years. Single-bubble sonoluminescence occurs when an acoustically trapped and periodically driven gas bubble collapses so strongly that the energy focusing on collapse leads to light emission. Because it is a new topic, few related experiments on this issue have been carried out before. However, while doing the research and making adjustments at the same time we discovered some special phenomenon: 1. Besides the normal amplitude frequency (30kHz) added on the bubble, we found that after a period of frequency which can not emit, the bubble is able to remain and emit in higher amplitude frequency (about 40 kHz). 2. We also compared the emission efficiency when bubbles are in different liquids. 3. To explain part of the results in high frequency and double-bubble sonoluminescence, we made two assumptions and attempted to demonstrated them in the end of the report. Some research studies in this field have been released already; nevertheless, few people concentrate on “double-bubble sonoluminescence.” Therefore, we attempt to systematically analyze the emission of double-bubble, expecting to have more comprehension of this marvelous effect and also establish the fundamental background to “muti-bubble sonoluninescence.”