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Upgrading graphite by flotation at Bogala Mines in Sri Lanka

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Journal of Central South University 2001年第3期13卷 193-196页

作者： M.R.Salgado (Central South University, changsha 410083, china) Central South University Changsha China

Graphite is naturally floatable due to its hydrophobic pro pe rty and also soft and smears on other gangue particles, rendering the gangue mor e or less floatable too. Due to this reason it is important to concentrate on ar eas such as suitable flotation reagents, depression agents, pH modifiers, and pa rticle size to be fed during the process. The paper surveys and analyses the sui table particle size to be fed to achieve high-grade concentrate. According to t h e work carried out the author suggested the ideal cost effective flotation f low sheet for improved results at Bogala Mines in Sri Lanka.

关键词： graphite flotation process reagent carbon percentage

MASS TRANSFER TO LIQUID-LIQUID INTERFACE

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Acta Metallurgica Sinica(English Letters) 1996年第2期9卷 151-156页

作者： LI Xinhai YIN Zhoulan(Central-South University of Technology,changsha 410083.china. Central-South Univ of Technology Changsha China

Experiments have been done on mass transfer to a liquid-liquid interface on which inert gas bubbles are *** simulate the pyrometallurgy system of melten slag-metal(or matte),aqueous solution-mercury(or zinc amalgam) system was *** mass transfer coefficients of indicator ions as a function of bubble parameters have been *** experimental results show satisfactory agreement with the mass transfer model proposed Previously.

关键词： mass transfer gas bubble liquid-liquid interface

Heat transfer analysis for the roller shell under the condition of periodic thermal shock

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Journal of University of Science and Technology Beijing 2003年第6期10卷 44-47页

作者： Lihua Zhan and Xiaoqian LiCollege of Electro-mechanical Engineering, Central South University, changsha 410083, china Coll. of Electro-Mech. Eng. Central South Univ. Changsha 410083 China

According to the actual working conditions of roller shell in the process ofcontinuous roll casting, the Fourier heat transfer law is used to conduct the simulating analysisfor the temperature distribution of the roller shell under the condition of periodic thermal *** temperature variation law inside the roller shell is studied during the process of continuousroll casting, and the steady temperature distributions of the roller shell at different castingvelocities have been obtained when the thermal contact conductance between the roller shell and thecasting strip is considered.

关键词： roller shell thermal contact conductance (TCC) periodic thermal shock

Ti/Al_2O_3 Functionally Gradient Material Prepared by the Explosive Compaction/SHS Process

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Journal of Materials Science & Technology 1999年第3期15卷 271-275页

作者： Yimin LI(Powder Metallurgy Research Institute, Central-South University of Technology, changsha 410083, china)Ziqiao ZHENG(Department of Materials Science and Engineering, Central-South University of Technology, changsha 410083, china) Powder Metallurgy Research Institute Central-South University of Technology Changsha 410083 China Department of Materials Science and Engineering Central-South University of Technology Changsha 410083 China

Ti1Al2O3 Functionally Gradient Material (FGM) was prepared by an explosive compaction/SHS process. Ten sheets of the compounding powder were laminated and pressed to get a green body of FGM. It was then compacted explosively By burying the explosive compaction body into a stoichiometric Al/TiO2 mixture and igniting the combustion of the stoichiometric Al/TiO2 mixture, the SHS reaction of the explosive compaction body was initiated by the heat released from the combustion of the stoichiometric Al/TiO2 mixture. In this way, Ti/Al2O3 FGM was synthesized. The adiabatic temperatures of each gradient layer were calculated when the preheating temperatures were 298 K and 1173 K, respectively The microstructure, composition and properties of Ti/Al2O3 FGM and the reaction mechanism of each gradient layer were studied. It was found that Ti/Al2O3 FGM prepared by the explosive compaction/SHS process had a high density and a high microhardness. Its structure, composition and properties showed apparent gradient distribution. The structure of the standard stoichiometric ratio gradient layer of FGM was a network structure. Its reaction mode could be described as follows: Al powder melted first, then the molten Al penetrated into the TiO2 zone and reacted with TiO2, and big pores were left in the original positions of Al powder. The reaction of gradient layers with the addition of Al3O3 as diluents was similar to that of the standard stoichiometric ratio gradient layer, so were their structure and composition. However, the reaction of gradient layers with the addition of Ti as diluents was more complex and the composition deviated slightly from the designed one

关键词： Al SHS Ti/Al2O3 Functionally Gradient Material Prepared by the Explosive Compaction/SHS Process

Boron rings containing planar octa- and enneacoordinate cobalt, iron and nickel metal elements

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Science china Chemistry 2008年第7期51卷 607-613页

作者： LUO Qiong School of Chemistry and Chemical Engineering, Central South University, changsha 410083, china School of Chemistry and Chemical Engineering Central South University Changsha China

For a series of boron rings with planar hyper-coordinate 8th group transition metal atoms, singlet 1FeB8-2, multiplet kFeB9n (n = -1, k = 1; n = 0, k = 2), singlet 1CoB8n(n = -1, +1, +3), multiplet kCoB9n (n = +1, k = 2; n = 0, k = 1) and singlet 1NiB9+, the geometry structures have been optimized to be local minima on corresponding potential hyper-surfaces. The electron structures are discussed by orbital analysis and the aromaticity is predicted by nucleus-independent chemical shifts calculation at both the B3LYP/6-311+G* and BP86/6-311+G* levels of theory, respectively. The results suggest that all these structures with high symmetry planar geometries are stable and have aromatic properties with six π valence electrons.

关键词： planar hyper-coordinate transition metal DFT

Research on common issues for relationship between mechanism degree of freedom,driving link and executive link

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Science china(Technological Sciences) 2009年第4期52卷 966-974页

作者： WANG AiLun College of Mechanical & Electrical Engineering, Central South University, changsha 410083, china Key Laboratory of Modern Complex Equipment Design and Extreme Manufacturing, Ministry of Education, changsha 410083, china College of Mechanical & Electrical Engineering Central South University Changsha China Key Laboratory of Modern Complex Equipment Design and Extreme Manufacturing Ministry of Education Changsha China

During engineering practice and theoretical research, the mechanism degree of freedom is sometimes unequal to the number of the driving link, which is unable to be explained according to the classic theory of the mechanism degree of freedom. To solve this problem, the duality description for operating laws of mechanism is introduced based on the concepts of duality. The Junction-Structure Equation is established for the port descriptions of general ideal mechanism and the functional description for the mechanism degree of freedom is described by utilization of bond graph theory. The force-transfer de- gree of freedom, i.e. the antithesis concept of movement-transfer degree of freedom, is introduced and defined based on the analysis of energy transfer as well as the analysis of signal causality. By utiliza- tion of structural description, functional description and duality description for the equation of degree of freedom, the relationship between the movement-transfer degree of freedom and force-transfer de- gree of freedom is further explored and analyzed. Thus, the relationship between the mechanism de- gree of freedom upon the driving link and the executive link is described generally. Finally, some typical relationships between the mechanism degree of freedom, the driving link and the executive link are analyzed.

关键词： duality bond graph Junction-Structure Equation driving link executive link degree of freedom

INFLUENCE OF HEAT TREATMENT ON THE MECHANICAL PROPERTIES OF RE Al-5.0Mg-0.6Cu ALLOY SHEET FOR AUTOMOBIL BODIES

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中国有色金属学会会刊：英文版 1993年第2期3卷 45-50页

作者： Sun,Xiaohua Wang,Mingpu Central South University of Technology,changsha 410083,china

The influences of solution temperature,time in solution and quenching rate on the mechanical properties ofRE Al-5.0Mg-0,6Cu(wt.-%)alloy sheets for automobile bodies have been *** results show the re-quirements for heat treatments for the alloy sheets were not *** this alloy sheets are easy to produceon an industrial *** experiments indicate that there exists slight age hardening in the *** typicalmicrostructures of the alloy have also been analysed.

关键词： heat treatment rare earth Al-Mg-Cualloy mechanical properties

Training, simulation, restoration expert system for power grid

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Journal of Central South University of Technology 2001年第1期8卷 69-73页

作者： LUO An,CHEN Qian (College of Information Engineering, Central South University, changsha 410083, china) College of Information Engineering Central South University Changsha China

The paper introduces some technology for training, simulation, restoration expert system of power grid, the structure of the system including function composition, hardware and software composition are discussed, knowledge representation and the method to establish device graphical library for expert system are given, the fault setting and diagnosis for training and simulation as well as restoration technology with deep first searching arithmetic and heuristic inference are presented. The research provides a good base for developing the training, simulation, restoration system of power companies.

关键词： training simulation restoration expert system power grid

METALLOGENIC CHARACTERISTICS AND OREPROSPECTINGFUTURE OF PRECAMBRIAN GOLD DEPOSITSIN MUFUJIULING DISTRICT

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Journal of Central South University 1996年第1期8卷 11-13页

作者： Wu Yanzhi(Department of Geology, Central South University of Technology,changsha 410083, china) Department of Geology Central South University of Technology Changsha 410083 China

MufuJiuling district is an important placer gold producing land since the ancient time. In recent years, some primary gold deposits and mineralizations, e. g., Huangjindong and Tulongshan gold deposits, have been found. But the metallogenic conditions and regularities as well as the oreprospecting future remain to be recognized. Through the study on the metallogenic background and condition, the auriferous source bed and the mineralizing characteristics, three types of primary gold deposits are confirmed to be prospective in this district and some key problems about their prospecting and evaluating are put forward.

关键词： primary gold deposit PreCambrian age metallogenic marker