外导热率和地热的地幔值来自声子生命周期
1Department of Earth and Planetary Science, Washington University, St. Louis, MO 63130, USA.
概括
本研究提出了酸盐和MgO的导热模型,准确预测实验数据. 该模型揭示了压力和温度如何影响热性质,影响石层和地幔地热.
科学领域:
- 地质物理学 地质物理学
- 固态物理 固态物理
- 材料科学 材料科学 材料科学
背景情况:
- 准确的热导率建模对于理解地球的热结构至关重要.
- 以前的模型经常难以捕捉热传输特性的压力和温度依赖性.
研究的目的:
- 开发和验证一个关于酸盐和MgO的导热性的综合模型.
- 为了阐明网格和辐射导热的压力和温度依赖性.
- 调查对石层和地幔地热的影响.
主要方法:
- 利用红外反射来获得用于模型开发的声子寿命.
- 纳入格鲁尼森参数,散装模量和热膨胀度来描述运输属性依赖.
- 开发了格子 (kappalat) 和辐射 (kapparad) 导热贡献的单独配方.
主要成果:
- 该模型成功地在环境条件下复制了实验热导率数据.
- 使用特定材料的参数 (a = 0.33对于酸盐,0.9对于MgO) 建立了卡帕拉特的温度和压力依赖的准确关系.
- 在Fe2+的存在下量化了压力独立的辐射贡献 (kapparad).
结论:
- 开发的模型为预测相关地质材料的导热率提供了一个强大的框架.
- 该模型的预测表明一个的岩层地热.
- 预计地幔地热在无水条件下是热的,在低速区的水合条件下是冷的.
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