Isotope Fractionation by Thermal Diffusion in Silicate Melts
Isotope Fractionation by Thermal Diffusion in Silicate Melts
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DOI：
10.1103/physrevlett.108.065901
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发表时间：
2012-02-10
影响因子：
8.6
通讯作者：
Lundstrom, Craig C.
中科院分区：
文献类型：
--
作者：
Lacks, Daniel J.;Goel, Gaurav;Lundstrom, Craig C.
同位素在热梯度中分馏，但在复杂流体中对这种效应的定量认识很少。本文介绍了硅酸盐熔体的实验结果和分子动力学模拟。我们表明，同位素分馏产生于经典的力学效应，并且基于Chapman-Enskog理论的标度关系可以预测复杂流体中的行为，而无需任意拟合参数。尺度分析表明，网络形成元素（Si和O）的分馏率明显低于网络调节剂（Mg、Ca、Fe、Sr、Hf和U）。
Isotopes fractionate in thermal gradients, but there is little quantitative understanding of this effect in complex fluids. Here we present results of experiments and molecular dynamics simulations on silicate melts. We show that isotope fractionation arises from classical mechanical effects, and that a scaling relation based on Chapman-Enskog theory predicts the behavior seen in complex fluids without arbitrary fitting parameters. The scaling analysis reveals that network forming elements (Si and O) fractionate significantly less than network modifiers (e. g., Mg, Ca, Fe, Sr, Hf, and U).