Abstract: The environment and architecture of Metallurgical Thermodynamic Database Application System (METHEDAS) which is implemented on the computer HITACH M-150 are described in this paper. This special database system consists of the following blocks: 1. a database, having memorized all the thermodynamic data of 2211 kinsd of inorganic substances (including elements) and 399 binary alloy systems; 2. a data management system, being able to provide users with four basic functions, namely Select, Update, Delete, Insert; 3. an application program library, having seven programs available forusers to calculate the thermodynamic qroperties of the chemical equilibrium systems; 4. a monitor system, monitoring and coordinating the activities of METHEDAS,
Abstract: By comparison with general database management system, the Metallurgical Thermodynamic Database Application System (METHEDAS) is a special one, which defined functions of database system are much simplified. In order to keep the data independence from application program, the necessary local logical data structure can be self-defined in every individual application program. The data file of METHEDAS is organized on basis of the direct access file, provided for the file management system of Vos2 operating system, and is designed to be a secondary indexed sequential file.
Abstract: Checking of user's commands in METHEDAS is the main subject in this paper.On basis of the syntactic structures of user's commands, the checking on following items: 1. command keywords and formats 2. parameter keywords, formats and their data types 3. rules of jointing commands with parameters is completed by means of a code conversion module and a syntax parsing module, which compose an interpreter. This interpreter, constructed within the FORTRAN-4 framework, is very successful in its simplicity, usefulness, and ability of simulating the string processing function, possessed by FORTRAN-77.
Abstract: we indicate in detail THERDYN program that is one of the application system of the metallurgical thermodynamics databases from its design to its flow chart in this paper. we have stated the function and the role of the program in the application of the metallurgical thermodynamics database as well as concrete application in the thermodynamics calculation.This program can calculate the thermodynamical properties of 2200 kinds of objects.
Abstract: The paper states the construction of metallurgical thermoaynamic database application system and introduces in detail the principle of algorithm and programs (three programs-REACTION DELTA and HATBL are to be mentioned) The paper studies the problem that how to apply this system to the metallurgical industry.
Abstract: In this paper we discussed Brinkley's method, YCS's method and White's method for the calculation of multicomponent and multiphase chemical equilibr ium.White's method has the advantage of high calculation speed.It is no use for White's method determining the independent reactions and to sort the independent variables.The initial values of composition are selected arbitrarily. On the basis of these reasons mentioned above White's method is chosen in our compu ter program.In the case of treating multiphase system, White's method developed by W.R.Smith is chosen to avoid the difficulty of numercial singularities when solving a set of linear equations. The paper introduced construction and principle of the program.The calculated results are conformed with the results that calculated by the database of Theoretical Metallurgical Institute of Rhein-isch Westfalische Techisvhe Hochschule Archen West Germany and the Inorganic Thermochemistry Database of the Institute of chemical Metallurgy Academia Sinica.
Monthly, started in 1955 Supervising institution：Ministry of Education Sponsoring Institution：University of Science and Technology Beijing Editorial office：Editorial Department of Chinese Journal of Engineering Publisher：Science Press Chairperson：Ren-shu Yang Editor-in-Chief：Ai-xiang Wu ISSN 2095-9389CN 2095-9389
