论文标题
从头开始确定地球核心的热演化
Ab initio determination on the thermal evolution of the Earth's core
论文作者
论文摘要
地球的磁场是由液体外芯产生的，并敏感地取决于芯的导热率。地球核心的主要组成部分是Fe和Ni。但是，目前对FENI混合物的估计值先前尚未在高压下进行测试。在本文中，首先将Ab Inti算模拟应用于地球外部核心条件下Feni混合物的热电导率和电导率的计算。与纯FE的结果相比，NI的添加降低了沿外部芯的绝热曲线的导热率（平均为12.30 W/m/k）。基于熵产量或焦点损失的限制，NI的存在延长了内核的年龄。当核心掩体边界的热流量为12 TW时，内芯的年龄为0.66 GA，具有纯Fe和0.67 GA，具有FENI混合物为0.67 GA。相比之下，我们观察到NI通过分析有效温度梯度来降低外芯中热分层的厚度。内部核心固化后，当纯FE的纯度分层的厚度为417.02 km，当核心掩体边界的冷却速率为126 K/ga时，纯Fe和320.12 km的厚度为320.12 km。
Earth's magnetic field is generated by the liquid outer core and sensitively depends on the thermal conductivity of the core. The dominant component of the Earth's core is Fe and Ni. However, current estimates on FeNi mixtures have not been previously tested at high pressures. In this paper, ab initio simulations were first applied to calculations of the thermal and electrical conductivities of FeNi mixtures at Earth's outer core conditions. Compared with the results for pure Fe, the addition of Ni decreases the thermal conductivity (12.30 W/m/K on average) along the adiabatic curve in the outer core. Based on the restriction of the entropy production rate or Joule losses, the existence of Ni prolongs the age of the inner core. The age of the inner core is 0.66 Ga with pure Fe and 0.67 Ga with an FeNi mixture when heat flow at the core-mantle boundary is 12 TW. In contrast, we observe that Ni decreases the thickness of thermal stratification in the outer core by analyzing the effective temperature gradient. After inner core solidification, the thickness of thermal stratification is 417.02 km with pure Fe and 320.12 km with an FeNi mixture when the cooling rate at the core-mantle boundary is 126 K/Ga.
