利用声致发光特征光谱探索声空化产生的极端高温高压

Based on measurements of the line spectra of atoms or ions in sonoluminescence (SL), this project will investigate the extreme high temperature and pressure inside the luminescing cavitation bubble. We plan that the host liquids will be sulfuric, phosphoric acid aqueous solutions, and pure water as well. Both noble gases such as argon, krypton and xenon, and some solutes such as sodium, potassium and terbium salts, will be dissolved into the host liquids. The SL spectra will be experimentally measured in these host liquids. The central wavelength, full width half maximum (FWHM) and profile of the characteristic spectra will be observed and recorded in detail. In theory a profile broadening and shift model for the characteristic spectrum will be proposed in consideration of both high temperature and pressure. Line spectra emitted at different temperature and pressure can be used to verify the theoretical model and improve its accuracy by changing the driving pressure of SL. Finally, the high temperature and pressure determined by our model based on the SL characteristic spectrum can be further compared with those estimated by both the blackbody radiation model of the SL continue spectrum and Rayleigh model of the cavitation bubble.

本项目旨在通过对声致发光中的原子离子特征谱线的测量，了解空化泡发光瞬间的极端高温高压。具体拟以硫酸、磷酸水溶液以及纯水为工作液体，溶入氪气、氩气以及氙气等惰性气体和钠盐、钾盐以及稀土铽盐等溶质，进行单泡和多泡声致发光光谱测量。重点观察和记录溶质中的金属原子离子的线状特征谱线的中心波长、半高宽度和波形形状。理论上，分析高温度和高压力引起的原子离子特征谱线中心波长移动和波形展宽，构建温度和压力相关的线谱展宽和移动模型。通过改变驱动超声波的幅度，获取不同温度和压力下的特征谱线中心波长、宽度和波形数据，完善理论模型并提高其精确性。最后，将特征谱线确定的空化泡发光温度和压力与连续光谱黑体辐射模型、Rayleigh气泡动力学模型所估计的结果进行比较，评价其合理性。

通过本项目的研究，（1）实验观察到了多种单泡、多泡声致发光中的原子、离子特征光谱，主要包括氯化铽、硝酸铽水溶液中的Tb^3+离子的5D4->7DJ (J=3,4,5,6)跃迁和氢氧化钠、氯化钠水溶液中的Na原子2P3/2,1/2->2S1/2跃迁；（2）发展了反卷积多特征谱线分离技术，应用到Na原子双黄线，获得了Na原子特征谱线增宽，并在Doppler和Stark增宽理论框架里，得到了声致发光空化泡内部的温度和压力；（3）研究了声致发光特征谱线对驱动超声功率、离子原子浓度、溶入气体种类和浓度等的参数相关性；最后（4）还研究了声致发光声场中的附加反常衰减，并利用此附加衰减，设计了一种具有声能量传播不对称的双层流体系统。上述研究成果均已以论文形式在国际国内学术会议上交流和学术期刊上发表，对人类丰富声空化知识具有重要意义。