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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 {2. 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

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 {2. 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

Nonclassical Plane-crystallographic Groups and Their Applications IV

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International Journal of Minerals,Metallurgy and Materials 1998年第4期12卷 228-232页

作者： Lequan Min Xaodan zhang(Applied science school, school,university of science and technology beijing, beijing 100083,china. Applied science school University of Science and Technology Beijing Beijing 100083 China

Eight kinds of nonclasslcal periodic lattices with locally 8-fold rotational symmetries are *** can be described via nonclassical Planc-crystallographic groups. The periodic lattices may be interpreted bythe projections on the plane of the corresponding unit cells consisting of embedding polyhedrons, respectively. TheFourier-transform patterns of the Periodic lattices have striking approximate'8-fold rotational symmetries', some ofwhich are similar to those displaying in the electrton-diffraction patterns of so-called quasicrystals.

关键词： nonclasslcal crystallographic groups locoally 8-fold symmetry Fourier-transform patterns, quasicrystals

Calculation Models of Mass Action Concentrations for Metallic Melts Involving Monotectic

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Journal of university of science and {2. beijing 2001年第4期8卷 248-253页

作者： Jian Zhang Metallurgy school, university of {2. and technology beijing, beijing 100083, china Metallurgy school University of Science and Technology Beijing Beijing 100083 China

Based on the phase diagrams, measured activities as well asDeltaG(m) and DeltaG(xs), calculating models of mass action concentrations for metallic melts involving monotectic have been formulated. The calculated results agree with practice on the whole, showing that the models deduced generally can reflect the structural characteristics of these melts. The metastable compounds formed in the melts are of the types A(2.B(3), AB(2., A(2.B(3) or AB and A(2.B(3)+AB etc..

关键词： metallic melts monotectic activity mass action concentration

Numerical simulation of strain localization and damage evolution in large plastic deformation using mixed finite element method

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Journal of university of science and {2. beijing 2004年第3期11卷 273-277页

作者： Zhanghua chen Jiajian Jin Jiumei Xiao Applied science {2., university of science and technology beijing, beijing 100083, china Appl. Sci. Sch. Univ. of Sci. and Technol. Beijing Beijing 100083 China

An investigation of computer simulation is presented to analyze the effectsof strain localization and damage evolution in large plastic deformation. The simulation is carriedout by using an elastic-plastic-damage coupling finite element program that is developed based onthe concept of mixed interpolation of displacement/pressure. This program has been incorporated intoa damage mechanics model as well as the corresponding damage criterion. To illustrate theperformance of the proposed approach, a typical strain localization problem has been simulated. Theresults show that the proposed approach is of good capability to capture strain localization andpredict the damage evolution.

关键词： strain localization mixed element truesdell stress rate material damage

Effects of silver powder particle size on the microstructure and properties of Ag-Yb_2._3 electrical contact materials prepared by spark plasma sintering

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Rare Metals 2010年第4期29卷 366-370页

作者： chen Xiaohua,JIA chengchang,and LIU Xiangbing {2. of Materials science and Engineering,university of science and technology beijing,beijing 100083,china school of Materials science and Engineering University of Science and Technology Beijing Beijing China

mg-Yb2.3 electrical contact materials were fabricated by spark plasma sintefing （SPS）. The effects of silver powder particle size on the microstructure and properties of the samples were investigated. The surface morphologies of the sintered samples were examined by optical microscope （OM）, and the fracture morphologies were observed by scanning electron microscopy （SEM）. The physical and mechanical properties such as density, electrical resistivity, microhardness, and tensile strength were also tested. The results show that the silver powder particle size has evident effects on the sintered materials. Comparing with coarse silver powder （5 ktm）, homogeneous and fme microstmcture was obtained by fine silver powder （_〈0.5-1am）. At the same time, the electrical conductivity, microhardness, and tensile strength of the sin- tered samples with fine silver powder were higher than those of the samples with coarse silver powder. However, silver powder particle size has little influence on the relative densities, which of all samples （both by free and coarse silver powders） is more than 95%. The fracture characteristics are ductile.

关键词： composites electrical contact materials spark plasma sintering particle size microstructure physical properties mechanical properties

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, {2. 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

Theory for Constructing Generalized Synchronization and Applications

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International Journal of Minerals,Metallurgy and Materials 2000年第3期14卷 225-228页

作者： Xiaodan Zhang, Lequan Min (Applied science school, {2. of science and technology beijing, beijing 100083, china. Applied science school University of Science and Technology Beijing Beijing 100083 China

The approaches for constructing directionally coupled generalized synchronization (GS) systems are presented, which are available for the driving system and the respond system that are in GS via a given diffeomorphi... 详细信息

关键词： Chaos generalized synchronization predictability

The deep thermal characteristic of continental margin of the northern South china.Sea

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Chinese science Bulletin 2000年第18期45卷 1717-1722页

作者： ZHANG Jian & WANG Jiyang1. Graduate school, university of science and technology of china, Chinese Academy of {2.s, beijing 100039, china.2. Institute of Geology, Chinese Academy of {2.s, beijing 10002., china Graduate school University of Science and Technology of China Chinese Academy of Sciences Beijing China Institute of Geology Chinese Academy of Sciences Beijing China

Heat flow plays an important role in the study ot thermal structure and thermal evolutionof continental margin of the northern South china.Sea. The analysis of heat flow value shows that margin heat flow in the northern South china.Sea is relatively high setting, but the percentage of crustal heat flow is lower than 35% in terrestrial heat flow. The terrestrial heat flow exhibited a current of rise from the Northern Continental Margin to the Southern Central Basin. However, the proportion of crustal heat flow in terrestrial heat flow slowly dropped down in the same direction. It is suggested that the main factor causing high heat flow setting is the moving up of hot material from asthenosphere.

关键词： margin of northern South china Sea terrestrial heat flow thermal structures.