A practical experimental method is proposed to investigate thermal transport by characterizing the motion of plasma flows through a x-ray spectroscopic technique using tracers. By simultaneously measuring multiple parameters, namely, the mass-ablation rate, the temporal evolution of plasma flow velocities and trajectories and the temperature, it is possible to observe a variety of physical processes, such as shock wave compression, heating by thermal waves, and plasma thermal expansion, and to determine their relative importance in different phases during the irradiation of CH and Au targets. From a comparison with hydrodynamic simulations, we find significant differences in the motion of the plasma flows between CH and Au, which can be attributed to different sensitivities to the thermal transport process. There are also differences in the ablation and electron temperature histories of the two materials. These results confirm that velocities and trajectories of plasma motion can provide useful evidence in the investigation of thermal conduction, and the approach presented here deserves more attention in the context of inertial confinement fusion and high-energy-density physics.

应用FLS920P型稳态和时间分辨荧光光谱仪, 对三种品牌不同脂肪含量的纯牛奶和鲜奶(共9种)进行了荧光光谱的测量。 9种牛奶样品的三维荧光光谱显示, 牛奶的荧光峰值波长为349 nm左右, 半高宽为66 nm左右, 最佳激发波长为291 nm左右, 平均寿命为4.6 ns左右, 实验表明9种牛奶的荧光光谱除荧光强度外基本一致。 实验测得酪蛋白溶液的荧光峰值波长为344 nm, 半高宽为66 nm, 最佳激发波长为295 nm, 荧光寿命为4.1 ns。 酪蛋白的荧光峰值波长和荧光寿命与牛奶基本一致, 对比牛奶中其他荧光物质后, 推断牛奶的主要荧光物质为酪蛋白。 进一步探究9种牛奶荧光强度的差别, 对比9种牛奶最佳激发波长下的荧光发射光谱, 相同品牌的全脂牛奶荧光强度明显低于脱脂牛奶。 对比全脂牛奶、 脱脂牛奶和离心处理的全脂牛奶归一化后的荧光光谱, 离心后的全脂牛奶荧光强度介于全脂和脱脂之间, 离心使得脂肪减少, 散射降低, 从而导致荧光强度的增强。 牛奶的荧光发射全谱显示全脂牛奶的瑞利散射强度明显高于脱脂牛奶, 全脂牛奶的脂肪含量高, 散射强, 激发光入射全脂牛奶后更多地被散射, 导致全脂牛奶的瑞利散射强度高于脱脂牛奶。 光透过率曲线显示全脂牛奶的透过率都低于脱脂牛奶, 入射光通过全脂牛奶时, 除了一部分被酪蛋白吸收以外, 还有一部分因脂肪的散射而损失, 透过率减小, 使得全脂牛奶的透过率都低于脱脂牛奶。 使用荧光光谱技术在不进行预处理的情况下对牛奶进行检测, 确定了牛奶的主要荧光物质, 并对全脂牛奶和脱脂牛奶荧光强度存在差别的原因进行了解释。