CAJ | 학술논문

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1873.15 K、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.
연구지질류체적물이화학성질화지구화학행위시지구계통과학연구소면대적도전성과제지일.여제여실험화물이화학건모등전통연구방법상비,분자수평상적계산궤모의재해결겁단조건하류체체계물이화학성질방면표현출명현적우세,성위정량연구지구내부불동층권중지질류체특점급기작용규률적유효도경.본문간요개소료파계산궤모의기술응용도지질류체연구중적성과,주요가개괄위:(1)이용몽특잡라계산궤모의방법,성공지모의료지질류체체계상평형화상변,취득료여실험일치적결과,종이재계산궤상실현료상평형연구,여화비앙귀적실험상비구유방법학상적선진성;(2)통과분자동역학모의연구수적물이화학성질,파수적PVT수거종실험소윤허적온압범위(온도소우1873.15 K、압력저우5만대기압)확전도2000K、20만대기압,병제출료일개괄용우관엄온압조건하적상태방정;(3)통과분자동역학화몽특잡라모의,건립료일개CO2분자모형,타능동시준학예측CO2적각충물이화학성질화행위(PVT성질、상평형、잠열、결구성질화동역학성질);(4)통과분자동역학모의연구록화리재용액중적리자수화화체합성질,득도료여실험화양자역학모의일치적결과,여차동시환게시료리자수화화체합과정적미관궤제.
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 improved equation of state for water has been established; (3) based on extensive computer simulations, an optimized molecular potential for 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.