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Analysis of the carbon source for diamond crystal growth

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Chinese science Bulletin 2008年第6期53卷 937-942页

作者： LI Li1,2. XU Bin2.3 & LI MuSen1,2.1 school of materials {2. & engineering, Shandong University, Jinan 2.0061, china 2.Shandong engineering Research Center for Super Hard materials, Zoucheng 2.3500, china 3 school of materials {2. & engineering, Shandong Jianzhu University, Jinan 2.0101, china school of materials {2. & engineering Shandong University Jinan China Shandong engineering Research Center for Super Hard materials Zoucheng China school of materials {2. & engineering Shandong Jianzhu University Jinan China

The lattice constants of diamond and graphite at high pressure and high temperature (HPHT) were calculated on the basis of linear expansion coefficient and elastic constant. According to the empirical electron theory of solids and molecules (EET), the valence electron structures (VESs) of diamond, graphite crystal and their common planes were calculated. The relationship between diamond and graphite structure was analyzed based on the boundary condition of the improved Thomas-Fermi-Dirac theory by Cheng (TFDC). It was found that the electron densities of common planes in graphite were not continuous with those of planes in diamond at the first order of approximation. The results show that during the course of diamond single crystal growth at HPHT with metal catalyst, the carbon sources forming diamond structure do not come from the graphite structure directly. The diamond growth mechanism was discussed from the viewpoint of valence electron structure.

关键词：钻石晶体生长石墨碳源价电子结构

Mathematical Model for the Drying Process of Granular materials in a Fluidized Bed

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International Journal of Minerals,Metallurgy and materials 2000年第4期14卷 296-300页

作者： Xiulan Huai, Li Wang, Zhiyun Qu ( Mechanical engineering school, University of {2. and technology Beijing, Beijing 100083, china Chemical Industry Research Institute of Shanxi, taiyuan 030031, china) Mechanical engineering school University of Science and Technology Beijing Beijing 100083 China Chemical Industry Research Institute of Shanxi Taiyuan 030031 China

The experiment of granular materials, barley, drying in a fluidized bed was carried out to investigate the influence of the factors, inlet air temperature, air moisture, bed height and original moisture content of the dried materials on drying process. Based on the experimental data, a corresponding mathematical model is presented. As a conclusion, a higher inlet air temperature and a reasonable bed height should be used so as to increase the dring rate and to improve the product quality.

关键词： fluidization granular materials drying, experimental investigation mathematical model Information

NUMERICAL SIMULATION ON FORMING PROCESS OF EAR PORTION OF UPPER CASE

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中国有色金属学会会刊：英文版 1998年第4期8卷 71-74页

作者： Hao Nanhai, Xue Kemin and L Yan Department of Metal Forming, taiyuan Heavy Machinery Institute, taiyuan 03002., P. R.{2. school of materials science and engineering, Harbin Institute of technology, Harbin 150001, P. R.{2. Department of Metal Forming Taiyuan Heavy Machinery Institute Taiyuan 030024 China school of materials {2. and engineering Harbin Institute of Technology Harbin 150001 China

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关键词： die forging finite element method upper case

Research progress in synthesis and catalysis of polyoxometalates

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Progress in Natural science:materials International 2005年第5期15卷 385-394页

作者： GONG Yun1, HU Changwen1* and LIANG Hong2.1. Department of Chemistry, school of science, the Institute for Chemical Physics, Beijing Institute of {2., Beijing 100081, china 2. Chemical Industry Press, Beijing 10002., china) Sch. of Sci Inst. for Chem. Phys. Beijing Inst. of Technol. Beijing 100081 China Chem. Indust. Press Beijing 100029 China

Recent progress in the synthetic chemistry and catalysis of polyoxometalates (POMs) is reviewed. The novel POMs and their derivatives emerging in nearly three years (2.02.2.04) are introduced, including POMs with novel structure, POMs-organic hybrid compounds and host-guest complexes. Our review is focused on the elaboration of POMs' supramolecular chemistry.

关键词： polyoxometalates hybrid host-guest structure supramolecule catalysis.

A Series Piezoelectric Quartz Crystal Response Kinetics for *** Growth in the Presence of Cu(Ⅱ)

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Journal of Central South University 2000年第1期12卷 15-19页

作者： CHAI Li yuan 1,2.,WEI Wan zhi 2.YAO Shou zhuo 2.1. Department of Metallurgical science and engineering, Central South University of {2., Changsha 410083, china 2. College of Chemistry and Chemical engineering, Hunan University, Changsha Department of Metallurgical science and engineering Central South University of Technology Changsha China College of Chemistry and Chemical engineering Hunan University Changsha China

The kinetics on the growth of *** in the presence of Cu(Ⅱ) was studied using of series piezoelectric quartz crystal (SPQC). Arsenic ion inhibits the growth of *** , which is consistent with the previous results by other measuring methods. This further demonstrates that the SPQC can monitor the chemical activity of *** growth. Cupric ion accelerates the growth of *** . The mechanism was discussed, i. e., copper promotes the protein enzyme of *** , rusticyanin, to form over the range of cupric ion concentration studied. The reaction order of cupric ion in accelerating the bacterial growth is 0.067. The growth of *** is dependent on temperature, the apparent reaction activation energy decreases from 2..56 kJ/mol to 18.32.kJ/mol because of the addition of 10 mg/L Cu(Ⅱ) to the bacterial growth solution of pH 2.0 at initial inoculum of 10%.

关键词： series piezoelectric quartz crystal T.ferrooxidans growth kinetics sigmoid curve cupric ion

Effect of the silicon powder content on the properties of Al_2._3-SiC-Me composites

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science china(Technological sciences) 2009年第1期52卷 193-197页

作者： ZHANG ZhiHui1, RUAN GuoZhi1 & CHEN YunBo1,2.1 school of Material science and {2., Shandong University of science and technology, Qingdao 2.6510, china 2.Institute of Material {2., china Academy of Machinery science and technology, Beijing 100083, china school of Material science and {2. Shandong University of Science and Technology Qingdao China Institute of Material engineering China Academy of Machinery Science and Technology Beijing China

By means of transient plastic phase process, the Al2.3-SiC-Me composites were produced throungh adding metal aluminium and silicon-powder to Al2.3-SiC materials. Under the condition of the same content of silicon and aluminium mixed-powder, the effect of silicon powder addition on properties of Al2.3-SiC-Me composites was studied by means of XRD and EPMA analyses in the temperature range of 300℃―1600℃. The results indicated that the content of metal phase in the sample at 1600℃ increases with increasing silicon powder content. At the same time, when the temperature is lower than 1100℃, the strength of samples gradually increases with increasing temperature. However when the temperature is higher than 1100℃, the strength of samples gradually decreases with increasing temperature, and this change is very small. The results also indicated that at the same sintering temperature, the sample with 6% silicon powder has the maximum strength.

关键词： composites strength ceramic

Microstructure and Tribological Performances of 2.NiCr-Cr_3C_2.Coatings Prepared by Laser-Hybrid Plasma Spraying technology

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稀有金属材料与工程 2011年第S4期40卷 194-198页

作者： Li Shuqing1,2.Li Qilian2.Gong Shuili2.1Department of materials Processing engineering,{2. of materials science & engineering,Dalian University of technology,Dalian 116085,china 2.ational Key Laboratory of science and technology on Power Beam Processes,Beijing Aeronautical Manufacturing technology Research Institute,Beijing 10002.,china Dalian Univ Technol Sch Mat Sci & Engn Dept Mat Proc Engn Dalian 116085 Peoples R China Beijing Aeronaut Mfg Technol Res Inst Natl Key Lab Sci & Technol Power Beam Proc Beijing 100024 Peoples R China

The 2.NiCr-Cr3C2.coatings are deposited on 38CrMoAl substrate by air plasma spraying and laser-hybrid plasma spraying (LHPS) technologies,the coatings' microstructures and tribological performances were studied using an optical microscope,a scanning electron microscope,an X-ray diffraction,and an SRV high-temperature friction and wear *** the same time,the coating's bonding strength,microhardness are tested and *** test results indicate that the LHPS 2.NiCr-Cr3C2.coating achieves metallurgy bonding and has higher bonding strength and higher microhardness than the air plasma spraying coating for the addition of the laser *** laser power makes the 2.NiCr-Cr3C2.powders melt more sufficiently and has good fluidity and uniformity and therefore the LHPS 2.NiCr-Cr3C2.coating's microstructures become more compact and there are no big cracks and cavities in *** the above changes,the LHPS 2.NiCr-Cr3C2.coating has more excellent anti-high temperature abrasion performance and its friction coefficient is low and very stable,its main failure mechanism is a good combination of mild scratching and plastic deformation.

关键词： laser hybrid plasma spraying 2.NiCr-Cr3C2 coating performance

Ferroelectric properties of Bi_(3.4)Ho_(0.6)Ti_3O_(12. thin films prepared by sol-gel method

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science china(Technological sciences) 2008年第9期51卷 1439-1444页

作者： FU ChengJu1, HUANG ZhiXiong1, LI Jie2.& GUO DongYun3 1 school of materials {2. and technology, Wuhan University of technology, Wuhan 430070, china 2.school of Mechanical engineering, Chongqing University of {2. and technology, Chongqing 400050, china 3 Department of Physics, Wuhan University, Wuhan 430072. china school of materials {2. and technology Wuhan University of Technology Wuhan China school of Mechanical engineering Chongqing University of Science and Technology Chongqing China Department of Physics Wuhan University Wuhan China

We have prepared the Ho-substituted bismuth titanate (Bi3.4Ho0.6Ti3O12. BHT) thin films on Pt/Ti/SiO2.Si substrates using sol-gel method. The crystal structure and morphology of the films were characterized using X-ray diffraction and atomic force microscopy. The BHT film shows a single phase of Bi-layered Aurivillius structure and dense microstructure. The 2.r and 2.c of the 600-nm-thick BHT film were 38.4 μC/cm2.and 376.1 kV/cm, respectively at applied electric field 500 kV/cm. The dielectric constant and dielectric loss are about 310 and 0.015 at a frequency of 1 MHz, respectively. The Pr value decreased to 93% of its pre-fatigue values after 4.46×109 switching cycles at 1 MHz frenquency, and the BHT film shows good in-sulating behavior according to the test of leakage current.

关键词： Bi3.4Ho0.6Ti3O12 thin film sol-gel method ferroelectric property fatigue dielectric constant

Dynamic Mechanical Behaviour of Ultra-high Performance Fiber Reinforced Concretes

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Journal of Wuhan University of technology(materials {2.) 2008年第6期23卷 938-945页

作者：赖建中 Department of materials science & {2. Nanjing University of Science & Technology

Ultra-high performance fiber reinforced concretes （UHPFRC） were prepared by replacing 60% of cement with ultra-fine industrial waste powder. The dynamic mechanical behaviour of UHPFRC with different fiber volume fraction was researched on repeated compressive impact in four kinds of impact modes through split Hopkinson pressure bar （SHPB）. The experimental results show that the peak stress and elastic modulus decrease and the strain rate and peak strain increase gradually with the increasing of impact times. The initial material damage increases and the peak stress of the specimen decreases from the second impact with the increasing of the initial incident wave. Standard strength on repeated impact is defined to compare the ability of resistance against repeated impact among different materials. The rate of reduction of standard strength is decreased by fiber reinforcement under repeated impact. The material damage is reduced and the ability of repeated impact resistance of UHPFRC is improved with the increasing of fiber volume fraction.

关键词： ultra-high performance fiber reinforced concretes split Hopkinson pressurebar dynamic repeated impact