分子水平上研究地质流体的物理化学性质(英文)  

Molecular Level Study on the Physicochemical Properties of Geological Fluids

作　　者：张志刚[1] 段振豪[1] 

机构地区：[1]中国科学院地质与地球物理研究所,北京100029

出　　处：《中国科学院研究生院学报》2006年第1期137-143,共7页Journal of the Graduate School of the Chinese Academy of Sciences

基　　金：supportedby‘HundredScientistsProject’fundsawardedbytheChineseAcademyofSciencesandOutstandingYoungScientistFunds(#40225008)awardedbyNationalScienceFoundationofChina

摘　　要：研究地质流体的物理化学性质和地球化学行为是地球系统科学研究所面对的挑战性课题之一.与诸如实验和物理化学建模等传统研究方法相比,分子水平上的计算机模拟在解决极端条件下流体体系物理化学性质方面表现出明显的优势,成为定量研究地球内部不同层圈中地质流体特点及其作用规律的有效途径.本文简要介绍了把计算机模拟技术应用到地质流体研究中的成果,主要可概括为(1)利用蒙特卡罗计算机模拟方法,成功地模拟了地质流体体系相平衡和相变,取得了与实验一致的结果,从而在计算机上实现了相平衡研究,与花费昂贵的实验相比具有方法学上的先进性;(2)通过分子动力学模拟研究水的物理化学性质,把水的PVT数据从实验所允许的温压范围(温度小于1873.15K、压力低于5万大气压)扩展到2000K、20万大气压,并提出了一个适用于宽广温压条件下的状态方程;(3)通过分子动力学和蒙特卡罗模拟,建立了一个CO2分子模型,它能同时准确预测CO2的各种物理化学性质和行为(PVT性质、相平衡、潜热、结构性质和动力学性质);(4)通过分子动力学模拟研究氯化锂在溶液中的离子水化和缔合性质,得到了与实验和量子力学模拟一致的结果,与此同时还揭示了离子水化和缔合过程的微观机制.It is one of the challenging issues in geosciences to study the physical chemical properties and geochemical behaviors of geological fluids. Compared with conventional approaches of experiments and semi-theoretical modeling, computer simulation based on molecular modeling shows its advantages in quantitative predictions of the physical chemical properties of geological fluids under extreme conditions and emerges as a promising approach to find the characteristics of geological fluids and their interactions in different geospheres of the Earth interior. In this paper, we give a brief introduction of our experiences in applying computer simulation techniques into the research of geological fluids. The main results can be summarized as follows： （1） we have successfully reproduced the experimental phase behaviors of the typical geological systems with Monte Carlo simulations; （2） through comprehensive isothermal-isobaric molecular dynamics simulations, the PVT data of water have been extended beyond experimental range to about 2000K and 20GPa and an extensive computer simulations, improved equation of state for water an optimized molecular potential for has been established ; （3） based on carbon dioxide have been proposed. This model is expected to predict different properties of carbon dioxide （volumetric properties, phase equilibria, heat of vaporization, structural and dynamical properties） with improved accuracies; （4） with molecular dynamics simulations and careful analysis, we＇ve got various structural, dynamical and thermodynamical properties of lithium chloride ionic solvations and associations. These results not only agree well with experimental data and first principle calculation results, but also reveal some new insights into the microscopic ionic solvation and association processes.

关 键 词：地质流体 分子动力学 蒙特卡罗 计算机模拟 物理化学性质 地球化学 热力学 

分 类 号：P59[天文地球—地球化学]