声致发光线光谱辐射机制的研究

Sonoluminescence (SL) is the phenomenon that as an intensive ultrasound wave imposes on cavitation bubbles in liquid, a light is emitted from the bubbles during their violent implosion. The spectrum of SL is one of the interesting research subjects for people. Currently, Almost all experimental observations of line emissions from SL have been conducted in the solutions containing a noble gas, which seems that a noble gas is necessary to generate a line emission during SL.However,it is unclear that a noble gas plays a role in generating line spectum . Centered around the generation, measurement and mechanism on the line spectrum of SL in the solution without noble gas, this project will obtain the correlation between the line emission and the parameters such as driving sound pressure, the kind of solution and luminescent materials. Based on which, we will propose a model describing the role of materials inner bubble in generating a line emission, to explain the experimental phenomenon observed. This study can both prove that the generation of line emission during SL is not required a noble gas,and has the scientific value to explore the mechanism that a noble gas or other material helps to generate line emission during SL.

声致发光是指强超声作用液体中的气泡时，气泡急剧塌缩而迸发出短暂发光的现象。声致发光的光谱一直是人们感兴趣的研究课题之一。目前，在研究声致发光线光谱的实验中，几乎都会在实验液体中溶解一定量的惰性气体。惰性气体似乎是声致发光线光谱产生的必要条件之一，但是惰性气体对线光谱产生的作用机理并不完全清楚。本项目主要围绕多种无惰性气体溶液中声致发光线光谱的产生、测量及物理机制开展实验和理论研究，获得线光谱的产生对驱动超声，溶液类型和发光物质等参数的相关性。然后在此基础上，构建一个描述气泡内部物质对声致发光线光谱作用的理论模型，解释观测到的实验现象。该研究不但可以证明惰性气体不是声致发光线光谱产生的必要条件，而且对揭示惰性气体或其他物质对线光谱的作用机理具有重要的科学意义。

声致发光(sonoluminescence,SL)是指强超声作用液体中的气泡时，气泡急剧塌缩而迸发出短暂发光的现象。SL主要包括单泡声致发光（single-bubble sonoluminescence,SBSL）和多泡声致发光(multi-bubble sonoluminescence,MBSL)。气泡在发光阶段，气泡半径一般小于1微米，几乎不能通过仪器直接测量气泡内部的物理环境和物质结构成分。目前主要通过计算分析实验光谱去估测气泡内部的温度、压强和密度等物理环境以及物质结构成分。本项目主要围绕SBSL和MBSL线光谱的产生、测量及物理机制开展实验和理论研究，获得线光谱的产生对驱动超声，溶液类型和发光物质等参数的相关性。实验方面，采集了氯化铽(TbCl3)、硝酸铽[Tb(NO3)3]、氢氧化钠(NaOH)等水溶液中SBSL和MBSL的光谱；理论方面，构建了SBSL和MBSL线光谱的辐射模型，通过数值模拟分析了两种SL线光谱的辐射机制。对于单泡声致发光，我们得到硝酸铽[Tb(NO3)3]水溶液中发光气泡坍塌阶段，气泡内部温度、压强和电离度的空间分布，以及Tb(III)离子特征谱峰的渐变过程，该结果与实验结果基本一致。对于多泡声致发光，我们考虑强超声在含气泡液体中的声场分布，进一步了计算声场中任何一个位置处气泡辐射的光谱。用该模型计算了氯化铽(TbCl3)和氢氧化钠(NaOH)水溶液中的多泡声致发光光谱。结果表明Tb(III)离子光谱的强度与气泡内部的Tb(III)离子数密度正相关。Na原子特征光谱随声强的增大，Na原子双黄线谱峰由两个渐变成一个，谱峰的展宽增大，理论分析结果与实验结果基本一致。这些研究结果对揭示声致发光线光谱的辐射机理具有重要的科学意义。