稀土热力学数据库计算体系研究

【作者】 唐晓宁；

【导师】 谢刚；

【作者基本信息】 昆明理工大学 ， 冶金物理化学， 2011， 博士

【摘要】 稀土具有优异的光、电、磁、超导、催化等物理和化学性能,能与其他材料组成性能各异、品种繁多的新型材料,被广泛应用于电子、石油化工、冶金、机械、能源、轻工、能源保护、农业等领域。我国稀土资源极为丰富,具有储量大、分布广、矿种全、类型多、价值高等特点,稀土储量和产量均居世界第一位,在稀土材料的研究中也居世界领先地位。稀土化合物物性数据库的建立将有助于整合稀土研究的数据资料,完善稀土基础研究内容,建立一个可以共享的基础数据查询和计算模拟服务的平台。稀土化合物热力学数据库作为该数据库中最为重要、最为复杂的子数据库,有必要进行专门的研究和设计。本论文从热力学数据库的基本内容入手,详细研究了热力学基础数据计算模块、热力学过程计算模块和热力学平衡计算模块的基本功能、计算模型、程序逻辑和实现过程,主要的研究内容如下：1)根据热力学计算的基本要求、数据库信息存储的格式和程序计算的特点,确定了基础数据资料的内容、格式、单位、有效数字等项目,设计了基础数据的计算模型和程序逻辑,实现了热力学基础数据的存储、检索、计算等功能,为用户提供数据服务的同时,也为其他热力学计算模块提供基本的数据信息。2)设计了以化学反应方程式为基础的热力学过程计算模块,引入了压力和活度修正项,建立了非标准状态热力学计算的模型和程序逻辑,扩大热力学计算的使用范围。非标准状态热力学计算公式也将引入到其他热力学计算模块中。3)设计了部分热力学计算的辅助程序,分析了这些辅助程序应具备的功能、实现程序的逻辑过程以及必要的计算模型,为热力学计算的主要计算程序提供服务,也使得热力学数据库更加完善和用户友好。4)综述了复杂体系化学平衡和相平衡计算的发展过程,对三类平衡计算理论以及相应的计算方法进行了简单的介绍和评价。结合本数据库的基础数据内容,确定了以最小Gibbs自由能原理作为本数据库化学平衡计算的理论基础,并确定了使用简约梯度法(Reduced Gradient, RG)作为本数据库化学平衡模块的基本计算方法。5)参照简约梯度法的计算原则和体系Gibbs自由能计算特点,完整地设计了复杂体系化学平衡与相平衡计算的数学模型和程序逻辑,分析了计算过程中各种简化、优化处理手段的物理和数学意义,通过与文献数据的比较,证明了热力学平衡计算模块的可靠性和实用性。通过以上各个模块的设计和研究,基本实现了稀土化合物热力学数据库体系的构造研究,完成了一般热力学计算的主要功能,为今后热力学数据库的深度开发提供了理论基础和先决条件。更多还原

【Abstract】 Rare Earth has much more excellent physical and chemical properties, such as optical character, electrical character, and catalytic character etc. then, They are widely used in electronic, petrochemical, metallurgy, machinery, energy, light industry, energy conservation, agriculture and other fields. Rare Earth resources of China are very rich, and the reserves and production of which of China is ranked first of the world. Therefore, in the study of rare earth materials, China is also a world leader.To establish the database of rare earth physical properties will be favorable to integrate data and improve the content of Rare Earth basic research. So, it is necessary to specialized research and design the thermodynamics database of Rare Earth compounds which is the most important and most complex sub-database of rare earth physical properties. In this work, the chief research work of the database had been done, and which includes the thermodynamic basic data calculation module, the thermodynamic process calculation module and the thermodynamic equilibrium calculation module.The main detailed contents are as followed:1) According to the basic requirements of thermodynamic calculations, the information storage format of database, and the characteristics of program calculation, the content, format, units, significant figures and other projects of basis data had been confirmed firstly, and then designed the basic data model and program logic. Thus, the functions of thermodynamic data storage, retrieval, calculation could be achieved. It provides not only the data services for users, but also the basic data for the other thermodynamic calculation module.2) The thermodynamic process calculation module was designed based on the chemical reaction equation, and the correction term of pressure and the activity were introduced. In addition to, the model and program logic of non-standard state thermodynamic calculations also were established. The serviceable range of thermodynamic calculations was expanded, and it is possible to introduce the calculation formula of thermodynamic non-standard to the other thermodynamic calculation module.3) A part of auxiliary programs of the thermodynamic calculation are designed. They can not only provide services for main computer program of the thermodynamic calculation, but also makes the thermodynamic database more perfect.4) The development process of chemical equilibrium and phase equilibrium calculation of the complex system were also discussed. Through analysis of equilibrium calculation method and combination of the basic data contents of our database, we determined the principle of minimum Gibbs free energy calculated as the theoretical basis of chemical equilibrium calculation, and the Reduced Gradient method as the basic calculation of chemical equilibrium module.5) We completely designed the mathematical model and program logic of chemical equilibrium and phase equilibrium under the complex system. And the design reference to the calculation principles of reduced gradient method and calculation features of system Gibbs free energy. Besides, the physical and mathematical sense are analyze after a variety of simplifying and optimization during calculation process. By comparison with literature data, it is can prove that our thermodynamic equilibrium calculation module is reliability and practicality.Through the design and study for above each module, we have completed the structure study for the thermodynamic database system of rare earth compounds and the main function of the general thermodynamic calculations. It will provide the theoretical basis and prerequisite for future development of thermodynamic database.更多还原