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Copper Adsorption on Olivine

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International Journal of Minerals,Metallurgy and Materials 2000年第4期14卷 237-241页

作者： Lei Shao, Rolf A. Kleiv, Kunt L. Sandvik, Cunyi Song, Shouci Lu ( Resources engineering School, university of science and Technology beijing,{4., china Department of Geology and Mineral Resources engineering, Norwegian university of science a Resources engineering School University of Science and Technology Beijing Beijing 100083 China Department of Geology and Mineral Resources engineering Norwegian University of Science and Technology 7034 Trondheim Norway

Copper adsorption on olivine supplied by the A/S Olivine Production Plant at Aheim in western Norway was studied. The factors were evaluated which affect the uptake of copper. It is shown that the equilibrium pH of aqueous solution has the greatest influence on copper adsorption thanks to the competitive adsorption between proton and copper ions, and the adsorption of copper to olivine increases rapidly with pH increasing from 4.to 6. Moreover, initial copper concentration and olivine dose possess significant effect on copper adsorption, for the adsorption rate of copper increases with olivine dose increasing or initial copper concentration decreasing at the same pH. In addition, the ionic strength effect on the adsorption was also investigated, but it owns little effect on the adsorption process of copper due to the formation of inner sphere adsorption of copper on olivine. The experimental data show that olivine has a high acid buffer capacity and is an effective adsorbent for copper.

关键词： copper adsorption olivine, ionic strength acid mine drainage

Development and application of ergodicity model with FRCM and FLAR for hydrological process

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science china(Technological sciences) 2009年第2期52卷 379-386页

作者： WANG HongRui1, FENG QiLei2, LIN Xin3 & ZENG WenYi4.1 College of Water science, Key Laboratory for Water and Sediment sciences of the Ministry of Education, beijing Normal university, beijing 100875, china 2 School of science, beijing Institute of Education, beijing 100011, china 3 School of Mathematical sciences, beijing Normal university, beijing 100875, china 4.College of Information science and Technology, beijing Normal university, beijing 100875, china 1. College of Water science Key Laboratory for Water and Sediment Sciences of the Ministry of Education Beijing Normal University Beijing 100875 China 2. School of science Beijing Institute of Education Beijing 100011 China 3. School of Mathematical sciences Beijing Normal University Beijing 100875 China 4. College of Information science and Technology Beijing Normal University Beijing 100875 China

In this paper, a new ergodic property analysis model of hydrological process is proposed based on fuzzy-rough c-means clustering (FRCM), autocorrelogram, and fuzzy least absolute regression (FLAR). A precipitation time series (1951―2004. from Shanghai Hydrology Station is then analyzed with the model. The results show that the precipitation time series of April, May, June, and September has er-godic property. We conclude that in the long run, the precipitation of April, May, June, and September will not keep decreasing; it will converge to its mean value in some period.

关键词： hydrological process ergodic autocorrelogram fuzzy-rough c-means clustering fuzzy least absolute regression

Optimization of a serpentine flow field with variable channel heights and widths for PEM fuel cells

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science china(Technological sciences) 2010年第2期53卷 453-460页

作者： LIN Lin, ZHANG XinXin, FENG HuTing & WANG XiaoDong Department of Thermal engineering, School of Mechanical engineering, university of science and Technology {4., Bejing 100083, china 1. Department of Thermal engineering School of Mechanical Engineering University of Science and Technology Beijing Bejing 100083 China

The present study proposes a modified serpentine flow field design in which the channel heights vary along each straight flow path to enhance reactant transport and liquid water removal. An optimization approach, combining a simplified conjugate-gradient method (inverse solver) and a three-dimensional, two-phase, non-isothermal fuel cell model (direct solver), has been developed to optimize the key geometric parameters. The optimal design has tapered channels for channels 1, 3 and 4.and increasing heights for channels 2 and 5 with the flow widths first increasing and then decreasing. The optimal channel heights and widths enhance the efficiency by 22.51% compared with the basic design having all heights and widths of 1 mm. The diverging channels have a greater impact on cell performance than fine adjustments of the channel widths for the present simulation conditions. The channel heights have more effect on the sub-rib convection, while the channel widths affect the uniformity of the fuel delivery more. The reduced channel heights of channels 2–4.significantly enhance the sub-rib convection to effectively transport oxygen to and liquid water out of the diffusion layer. The final diverging channel prevents significant leakage of fuel to the outlet via sub-rib convection.

关键词： PEM fuel cell simplified conjugate-gradient method optimization sub-rib convection

Effect of Auxiliary Gases on Combustion Synthesis of Si_3N_4

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Journal of Materials science & Technology 2005年第5期21卷 701-704页

作者： Weiping SHEN+, Fei WANG, Zhuohii WU and Changchun GELab of Special Ceramics and P/M, university of science and Technology beijing, beijing 100083, {4. Lab. of Special Ceramics and P/M University of Science and Technology Beijing Beijing 100083 China

This paper presents results of combustion synthesis （Self-Propagating High Temperature Synthesis, SHS） of Si3N4.under nitrogen with argon, hydrogen or ammonia. Higher percentages of α-Si3N4.content were obtained in large size cakes in SHS with hydrogen and ammonia than those with argon. Effect of the auxiliary gases for combustion synthesis of Si3N4.on a phase content, on phase transformation of α-Si3N4.to β-Si3N4.in SHS Si3N4.and on oxygen content in SHS Si3N4.were investigated.

关键词： Combustion synthesis m-silicon nitride Phase transformation Auxiliary gases

A New Scheme and Microstructural Model for 3D Full 5-directional Braided Composites

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Chinese Journal of Aeronautics 2010年第1期23卷 61-67页

作者： Zhang Fan,Liu Zhenguo,Wu Zhe,Tao Guoquan School of Aeronautic science and engineering,beijing university of Aeronautics and Astronautics,beijing 100191,china [a] School of Aeronautic science engineering Beijing University of Aeronautics Astronautics Beijing 100191 China

Three-dimensional（3 D）braided composites are a kind of advanced ones and are used in the aeronautical and astronautical fields more widely. The advantages, usages, shortages and disadvantages of 3D braided composites are analyzed, and the possible approach of improving the properties of the materials is presented, that is, a new type of 3D full 5-directional braided composites is developed. The methods of making this type of preform are proposed. It is pointed out that the four-step braiding which is the most possible to realize industrialized production almost has no effect on the composites＇ properties. By analyzing the simulation model,the advantages of the material compared with the 3D 4.directional and 5-directional materials are presented. Finally, a microstructural model is analyzed to lay the foundation for the future theoretical analysis of these composites.

关键词： 3D braided fabrics four-step braiding 3D full 5-directional braided composites preform microstructure

Dynamic recrystallization during hot torsion of Al-4.g alloy

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Journal of university of science and Technology beijing 2003年第2期10卷 45-48页

作者： Junpin Lin, Yanli Wang, Zhi Lin, and Guoliang ChenState Key Laboratory of Advanced Metal Materials, university of science and Technology beijing, beijing 100083, {4. Lab. of Adv. Metal Mat. Univ. of Sci. and Technol. Beijing Beijing 100083 China

Binary Al-4.g alloy have been deformed by hot torsion at 300-500 deg C andstrain rates of 0.006-1.587 s^(-1) to a true strain of 5.5. The specimens were annealed in vacuumfor 1.5 h at 500 deg C and then water quenched. The study indicates that the dynamicrecrystallization occurs during hot torsion of Al-4.g alloy in a certain range of Z parameter(Zener-Hollmon Parameter), i.e. 19.3 4.8. Increasing the strain rate at higher deformationtemperature or reducing the strain rate at lower deformation temperature accelerates the occurrenceof dynamic recrystallization in the alloy.

关键词： Al-4.g alloy dynamic recrystallization hot torsion

Immersing Treatment of Steel Plate Surface in Steel-Aluminum Solid to Liquid Bonding

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International Journal of Minerals,Metallurgy and Materials 1999年第1期13卷 57-60页

作者： Peng Zhang Yunhui Du Xueping Ren Yonglin Kang Hanwu Liu Jianzhong Cui Limin Ba (Material science and engineering School, university of science and Technique {4., beijing 100083, china)(Metal Forming Department Northeastern university, Shenyang 1 Material science and engineering School University of Science and Technique Beijing Beijing 100083 China Metal Forming Department Northeastern University Shenyang 110006 China Anshan Automobile Fittings Factory Anshan 114014 China

The interfacial status of the steel-aluminum solid to liquid bonding plates (their steel plate surfaces were or were not immersed in flux aqueous solution) were measured by using SEM (Scanning Electron Microscope) and X-ray diffraction . The results showed that the layer of flux (the minimum thickness was 15 μm on the steel plate surface) could protect the steel plate surface from oxidizing effectively at high temperature in solid to liquid bonding. The melt temperatUre of the flux should be lower than 580 ℃ so that it could be melted and removed completely. No. 1 flux (patent product made by the author) made up of halogeindes could also force liquid aluminum to infiltrate into steel plate surface and thus the interfacial shear strength of the bonding plate was rather large.

关键词： steel-aluminum solid to liquid bonding plate steel plate surface immerse, flux, melt temperature interfacial shear shrength

Physical and Electrochemical Properties of Acid 1-Methyl-3-Ethylimidazolium Chloride/AlCl_3/LiAlCl_4.Molten Salt

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International Journal of Minerals,Metallurgy and Materials 2000年第4期14卷 286-291页

作者： Ying Sing Fung, Ruqi Zhou ( Department of Chemistry, The university of Hong Kong, Hong Kong, china Department of Inorganic and Non-metal Materials, university of science and Technology {4., beijing 100083, china) Department of Chemistry University of Hong Kong Hong Kong Hong Kong Department of Inorganic and Non-metal Materials University of Science and Technology Beijing Beijing 100083 China

An acid molten salt was formed by means of mixing 1 -methyl- 3 -ethylimidazolium chloride with AlCl3 and LiAlCl4.at ambient temperature. The solubility of LiAlCl4.in the acid molten salt was measured. Variations of specific conductivity, density and kinetic viscosity of molten salt with mole ratio o f MeEtlmCl/A1lCl3/LiAlCl4.were observed. A solubility maximum of LiAlCl4.with 5 4. in molar fraction was shown at a mole ratio of AlCl4./MeEtlmCl = 1 .2. An increase in density and viscosity, and a decrease in specific conductivity were found with increasing the concentrations of LiAlCl4.and AlCl3. The dependence of specific conductivity of this acid molten salt upon temperature was found to display Vogel-Tammanm-Fucher behavior. However, Arrhenius behavior was observed at two special mole ratios of MeEtImCl/AlCl3/LiAlCl4.= 1:1.5:0.05 and 1. 1.5:0. 10. The conductivity equations of this molten salt at various compositions were constructed. The ion interaction in the acid molten salt was studied using 7Li and 27Al nuclear magnetic resonance spectroscopic methods. The effect of concentrations of LiAlCl4.and AlCl3 on the ion interaction was also discussed.

关键词： Li-7 NMR Al-27 NMR room temperature molten salt aluminum chloride lithium tetrachloroaluminate physical property electrochemical property Materials

Crystallization Mechanism of Na_2O-CaO-Al_2O_3-SiO_2-F Glass Containing Cr_2O_3

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International Journal of Minerals,Metallurgy and Materials 1999年第3期13卷 214-218页

作者： Lidong Teng Fuming Wang Wenchao Li(Department of inorganic Materials, Shandong Institute of Light Industry, Jinan 250100, china)(Applied science School, university of science and Technology {4., beijing 100083, china) Department of Inorganic Materials Shandong Institute of Light Industry Jinan 250100 China Applied science School University of Science and Technology Beijing Beijing 100083 China

The effect of Cr2O3 on the nucleation and crystallization of Na2O-CaO-Al2O3-SiO2-F- glass has been investigated by means of ESR(Electron Spin Resonance), SEM(Scanning Electron Microscope), EDS(Energy Dispersive Specrometer) and so on. Computer pattern recognition is applied to optimize the heat-treatment schedules. The experimental results show that the base glass containing more than 1 .5 % (mass fraction) Cr2O3 can be nucleated internally and converted to spheroidal crystal glass materials. The spheroidal crystal consisted of fibrous wollastonite crystals radiating from a center. The residual glass phase filled in the interstices between the fibers and between the spherulites. During heat treatment process, the valence states ofchromium changed from Cr6- to Cr3-, and the Cr-spinel solidsolution [CaCr2O4. precipitated followed this valence change. At the primary stage of crystallization, the Cr-spinel could act as a nucleating center on which the principal or}stalline phase β-CaSiO3 grew epitaxially.

关键词： crystallized glass Na_2O-CaO-Al_2O_3-SiO_2 Cr_2O_3 pattern recognition