Transport properties of hydrogen-helium mixtures at extreme density and temperature conditions.
Transport properties of hydrogen-helium mixtures at extreme density and temperature conditions.
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DOI：
10.1103/physreve.92.043108
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发表时间：
2015-10
期刊：
影响因子：
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通讯作者：
Dafang Li;Cong Wang;W. Kang;Jun Yan;Ping Zhang
中科院分区：
文献类型：
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作者：
Dafang Li;Cong Wang;W. Kang;Jun Yan;Ping Zhang
我们使用量子分子动力学（QMD）对氢氦混合物进行了系统的研究，重点是状态方程以及结构和输运性质，如电导率，扩散和粘度，在巨行星内部的条件下为0.2 × 2.3 g/cm（3）和1000 × 80，000 K，典型的氦质量分数为0.245。通过分析轨道和对分布函数，发现低温下氢氦分离。我们发现，扩散系数表现出从动力学的潜在的过渡，然后到分层为主的制度。此外，我们确定了在低密度和温度条件下的H-He混合物的光学吸收的不连续性的功能，这是从带内到带间跃迁的变化的结果。讨论了扩散系数与粘滞系数之间的Stokes-Einstein关系。
We perform a systematic study of hydrogen-helium mixtures using quantum molecular dynamics (QMD) with a focus on the equations of state and structural and transport properties such as electrical conductivity, diffusion, and viscosity at conditions of giant planet interiors of 0.2∼2.3 g/cm(3) and 1000∼80,000 K for a typical helium mass fraction of 0.245. The H-He separation is found at low temperatures by analyzing the trajectories and pair distribution functions. We show that the diffusion coefficients exhibit transitions from kinetics- to potential-, and then to demixing-dominated regimes. In addition, we identify the discontinuity feature of optical absorption of a H-He mixture at low density and temperature conditions, which results from the change from an intraband to an interband transition. The Stokes-Einstein relation between the diffusion and viscosity coefficients is also discussed.