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Production of O' -sialon-SiC Composites by Carbon Reduction-Nitridation

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International Journal of Minerals,Metallurgy and Materials 1998年第1期12卷 26-30页

作者： Haijun Zhang Wenchao Li Xiangcong Zhong (Applied science school, University of science and technology beijing, beijing 1 0008 3, china) Applied science school University of Science and Technology Beijing Beijing 100083 China

The effect of temperature, soak times, carbon and addition on composites was discussed in the process ofsynthesizing O'-sialon-SiC by carbonthermal reduction-nitration from nature kaolin. It showed that the fracturestrength (MOR) of composites sintered under certain conditions can be up to 140MPa at room temperature. Thetarget parameter optima regions with good mechanical properties of this material were also indicated by usingcomputer pattern recognition program.

关键词： O'-sialon-SiC compostites carbonthermal reduction-nitration pattern recognition program

Recycling of Spent Nickel-Cadmium Batteries

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International Journal of Minerals,Metallurgy and Materials 2000年第2期14卷 126-131页

作者： Xanghua Kong Pingnan Wu(Metallurgy school, university of science and technology beijing, beijing 100083, china) Metallurgy school University of Science and Technology Beijing Beijing 100083 China

A technique for recycling spent nickel-cadmium batteries, which makes separaion of cadmium and nickel possible, is developed by laboratory-scale experiments. NH3-H2CO3 aqueous solution was used in this leaching technique. Since neutralization and/or solvent extraction were not required in the separation procedure of nickel and cadmium, the closed systemizaion of the process becomespossible. Experimental results show that, (1) if the NH3 concentraion of leaching solution is sufficiently high and the ratio of H2CO3 toNH3 is properly adjusted, both Ni(OH)2 and Cd(OH)2 react with NH, and quickly dissolve into leaching solution, and (2) Ni(OH)2 can beconverted into insoluble NiO by calcination at 500℃, and CdO from Cd(OH)2 by calcination maintains good solubility in NH3-H2CO3aqueous solution. As a conclusion, the recycling technique characterized by two step leaching can be developed based on such changesin dissolution behavior by calcination. Meanwhile, the yields of 99.8% for nickel and 97.6% for cadmium are obtained, and the puritiesof Recycling of Spent Nickel-Cadmium BatterieRecycling of Spent Nickel-Cadmium Batteries Recycling of Spent Nickel-Cadmium Batteriesrecovered nickel and cadmium are 99.9% and 98.6%, respectively.

关键词： nickel-cadmium batteries recycling, ammonia leaching closed system environmental protection

Nonlinear Theory on Dynamic Controlling Interface Patterns DuringSolidification of a Dilute Binary Alloy

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International Journal of Minerals,Metallurgy and Materials 1999年第4期13卷 253-258页

作者： Zidong Wang Hanqi Hu(Material science and Engineering school, University of science and technology beijing, beijing 100083, china) Material science and Engineering school University of Science and Technology Beijing Beijing 100083 China

In non-equilibrium nonlinear region, the nonlinear equations of time dependence of perturbation amplitude at the solid/liquidinterface during solidification of a dilute binary alloy are established on the base of assuming that there is local equilibrium at the solid/liquid interface and considering that curvature, temperature and composition at the solid/liquid interface which are related to the perturbation amplitude are nonlinear. As a result, patterns at the solid/liquid interface during solidification process, which is from nonsteadystate to steady state can be controlled by these nonlinear equations.

关键词： nonlinearity solidification, dilute binary alloy, dynamic control

CABOSFV algorithm for high dimensional sparse data clustering

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Journal of University of science and technology beijing 2004年第3期11卷 283-288页

作者： Sen Wu Xuedong Gao Management school, University of science and technology beijing, beijing 100083, china Mgmt. Sch. Univ. of Sci. and Technol. Beijing Beijing 100083 China

An algorithm, Clustering Algorithm Based On Sparse Feature Vector (CABOSFV),was proposed for the high dimensional clustering of binary sparse data. This algorithm compressesthe data effectively by using a tool 'Sparse Feature Vector', thus reduces the data scaleenormously, and can get the clustering result with only one data scan. Both theoretical analysis andempirical tests showed that CABOSFV is of low computational complexity. The algorithm findsclusters in high dimensional large datasets efficiently and handles noise effectively.

关键词： clustering data mining sparse high dimensionality

New progress in the principle of nonequilibrium statistical physics

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Chinese science Bulletin 2001年第6期46卷 448-454页

作者： XING XiusanDepartment of Applied Physics, beijing institute of technology, beijing 100081, china Department of Applied Physics Beijing Institute of Technology Beijing China

In recent years, a new fundamental equation of nonequilibrium statistical physics was proposed in place of the Liouville equation. That is the anomalous Langevin equation in (?) space or its equivalent Liouville diffusion equation of time-reversal asymmetry. This equation reflects that the form of motion of particles in statistical thermody-namic systems has the drift-diffusion duality and the law of motion of statistical thermodynamics is stochastic in essence, but does not obey the Newton equation of motion, though it is also constrained by dynamics. The stochastic diffusion of the particles is the microscopic origin of macroscopic irre-versibility. Starting from this equation, the BBGKY diffusion equation hierarchy was presented, the hydrodynamic equations, such as the generalized Navier-Stokes equation, the mass drift-diffusion equation and the thermal conductivity equation have been derived succinctly. The unified description of all three level equations of microscopic, kinetic and hydrodynamic

关键词： anomalous Langevin equation in space drift-diffusion duality stochastic law nonequilibrium entropy evolution equation entropy diffusion.

A New Safety Electric Initiating System

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International Journal of Minerals,Metallurgy and Materials 1999年第4期13卷 306-308页

作者： Daze Lin(Resource Engineering school, University of science and technology beijing, beijing 100083, china) Univ of science and technology Beijing Beijing China

Based on the analysis of weakness on the safety of traditional electric detonators, a BJ-l safety electric detonator initiatingsystem and its corresponding safe examination technique were successfully developed. By leading false foot wires and taking advantageof the transmitting frequency band of Mo-Zn ferrite, detonators in this new system can completely impede the direct induction of outsidecrosstalk that may cause casual firing in the ordinary as well as eleclromagnetic ones. Possible causality by lightning was discussed. Results are presented, of its safety tests on resistance to direct and alternating current, electrostatic, and crosstalk induced by damp leakagein saturated salty water.

关键词： electric detonator blasting engineering, electric initiating system, safety

Feller property and exponential ergodicity of diffusion processes with state-dependent switching

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science china Mathematics 2008年第3期51卷 329-342页

作者： XI FuBao Department of Mathematics, beijing institute of technology, beijing 100081, china Department of Mathematics Beijing Institute of Technology Beijing China

In this paper we consider the Feller property and the exponential ergodicity for general diffusion processes with state-dependent switching. We prove their Feller continuity by means of intro- ducing some auxiliary processes and by making use of the Radon-Nikodym derivatives. Furthermore, we also prove their strong Feller continuity and their exponential ergodicity under some reasonable conditions.

关键词： Feller continuity Radon-Nikodym derivative strong Feller continuity exponential ergodicity state-dependent switching 60J60 34D25

Producing Calcium-Bearing Mullite Thermal-Insulating Refractories by Kyanite

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International Journal of Minerals,Metallurgy and Materials 1999年第1期13卷 50-53页

作者： Wen Ni (Resources Engineering school, University of science and technology beijing, beijing 100083, china) Resources Engineering school University of Science and Technology Beijing Beijing 100083 China

To improve the physical properties, a series of experiments have been camed out to produce calcium-bearing mullite thermal-insulating refractories by using kyanite as major raw materials. The experiments were carried out by a foaming technique and using white cement as a combing agent. The results show that the calcium-bearing mullite refractory has much better physical properhes than traditional clay refractory and high-alumina refractory.

关键词： mullite thermal-insulating refractory kyanite

Comparison of Some Methods on Prediction of Activity Interaction Coefficient

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International Journal of Minerals,Metallurgy and Materials 1998年第1期12卷 13-15页

作者： Changxiang Xiang Ningxin Zhang (Applied science school, University of science and technology beijing, beijing 100083, china) Applied science school University of Science and Technology Beijing Beijing 100083 China

Based on Miedema's semiempirical formation enthalpy model for binary alloys, free volume theory and ageneral solution model, a new model for prediction of activity interaction coefficient ε is proposed. The calculatedresults are better in agreement with the experimental values than the two previous models. The related theories andmodels are discussed according to the degree of agreement with experimental values.

关键词： Miedema's semiempirical formation enthalpy model activity interaction coefficient free volume theory similarity coefficient