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Novel electrodeposition process for preparinghydroxyapatite coating on titanium substrate

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中国有色金属学会会刊：英文版 2005年第6期15卷 1367-1372页

作者：赵中伟李洪桂孙培梅陈星宇 Okido Masazumi School of Metallurgical Science and Engineering Central South University Changsha 410083 Hunan Department of Materials Science School of Engineering Nagoya University Nagoya 464-8603 Japan

A novel process for electrodeposition of hydroxyapatite coating on titanium substrate was developed. The mechanism of the electrochemical reaction on the cathode was changed by adding H2O2 into the electrolyte. The evolution of H2 gas was erased. And owing to the fact that H2O2 posesses high tendency of being reduced, a fairly high cathodic current can be gained at a more positive potential than -1.0V. During the electrodeposition, 6%H2O2 is added, the temperature of deposition is fixed at 55℃ and pH of electrolyte is adjusted to 5.5. Dense and homogeneous film is crystallized at high rate. The mechanism of crystallize process was discussed.

关键词：电解沉积钛合金生物材料羟基磷灰石生物陶瓷极化

Surface tension of molten tin investigated with sessile drop method

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中国有色金属学会会刊：英文版 2005年第5期15卷 1166-1171页

作者：李晶袁章福范建峰柯家骏 Multi-phase Reaction Laboratory Institute of Process Engineering Chinese Academy of Sciences Beijing 100080 China

The surface tension of molten tin was determined by a set of self-developed digital equipment with sessile drop method at oxygen partial pressure of 1.0×10 -6MPa under different temperatures, and the dependence of surface tension of molten tin on temperature was also discussed. The emphasis was placed on the comparison of surface tension of the same molten tin sample measured by using different equipments with sessile drop method. Results of the comparison indicate that the measurement results with sessile drop method under the approximate experimental conditions are coincident, and the self-developed digital equipment for surface tension measurement has higher stability and accuracy. The relationships of surface tension of molten tin and its temperature coefficient with temperature and oxygen partial pressure were also elucidated from the thermodynamic equilibrium analysis.

关键词：锡熔化工艺界面结构金属结构金属物理学

Preparation of ZrO_2-Al_2O_3 micro-laminated coatings on stainless steel and their high temperature oxidation resistance

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中国有色金属学会会刊：英文版 2005年第6期15卷 1388-1393页

作者：姚明明何业东缑英俊高唯 Beijing Key Laboratory for Corrosion Erosion and Surface Technology University of Science and Technology Beijing Beijing 100083 ChinaSchool of Chemistry and Chemical Engineering Ji'nan University Ji'nan 250022 China Beijing Key Laboratory for Corrosion Erosion and Surface Technology University of Science and Technology Beijing Beijing 100083 China School of Chemistry and Chemical Engineering Ji'nan University Ji'nan 250022 China School of Engineering The University of Auckland Private Bag 92019 Auckland New Zealand

Micro-laminated ZrO2-Al2O3 coatings were prepared by electrochemical depositing ZrO2 film and Al2O3 film alternatively in ethanol solutions containing aluminum nitrate and zirconium nitrate, with small amounts of （yttrium） nitrate added respectively into both solutions. The micro-laminated ZrO2-Al2O3 coating is of nanostructure. FE-SEM analyses show that the cross section of the micro-laminated coatings has alternate six-layer films of ZrO2 and Al2O3, with the thickness of each layer in the range of nanometer or submicron. The surface of the （micro-）（laminated） coatings is composed of nano-particles. SEM, XRD and mass gain measurement were adopted to study the oxidation resistance of coatings on stainless steel. It has been found that all the coatings are effective in protecting the substrate from oxidation, and micro-laminated coatings exhibit more excellent protectiveness performance. Mechanisms accounting for such effects have been discussed.

关键词： ZrO2 Al2O3 不锈钢高温氧化涂层 FEM

Synthesis, Crystal Structure and Reactivity of (2,4-C_7H_(11) )_2Yb·DME

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Chemical Research in Chinese Universities 2001年第1期17卷 14-19页

作者： ZHANG Suo-bo LIU Ju-zheng ZHUANG Xiu-li HUANG Jing-qin HU Ning-hai CHEN Wen-qi Department of Chemistry Jilin UniversityChangchun 130023P.R.China Changchun Institute of Applied Chemistry Chinese Academy of SciencesChangchun 130022P.R.China

(2,4 C 7H 11 ) 2Yb·DME was synthesized by the reaction of YbCl 3 with K(2,4 C 7H 11 )(2,4 dimethylpentadienyl potassium), and the single crystal X ray diffraction showed that the complex exists in a cis staggered conformation. The crystal of the compound belongs to the monoclinic space group P2 1/n with a =0.875 2 (1) nm, b =1.490 6(1) nm, c =1.529 3(2) nm, β =97 55(2)° , V =1.977 79(4) nm 3, Z =4, F (000)=735.8 e, μ =49.49 cm -1 , R =0.033 and R w=0.032 . The title complex can be used as a catalyst for the polymerization of methyl methacrylate(MMA).

关键词： Dimethylpentadienyl Synthesis Crystal structure Catalyst Polymerization

Prediction of thermodynamic properties for multicomponent system with Chou model

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中国有色金属学会会刊：英文版 2000年第5期10卷 642-644页

作者：甄强包宏王福明李文超 Univ Sci & Technol Beijing Dept Chem Phys Beijing 100083 Peoples R China

A new geometrical model, Chou model, was developed as a computer program for calculating thermodynamic properties of multicomponent system. Calculated results show that the new model is more reasonable and convenient than other symmetrical (or asymmetrical) models. With this model, the excess Gibbs free energies of Ga Al As In compound semiconductor system were calculated. [

关键词： thermodynamic properties new geometrical model Ga Al As In alloy

Corrosion electrochemical behavior of brass tubes in circulating cooling seawater

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中国有色金属学会会刊：英文版 2005年第3期15卷 619-625页

作者：卢玉琢宋诗哲尹立辉 School of Materials Science and Engineering Tianjin University Tianjin 300072 China State Key Laboratory for Corrosion and Protection of Metals Shenyang 110016 China

Electrochemical impedance spectroscopy (EIS) and electrochemical noise (EN) were used to study the corrosion electrochemical behavior of brass tubes in circulating cooling seawater using the developed sensor. EIS study shows that the inhibitor can lead to the formation of corrosion products on metal surface, which will then inhibit the corrosion process. When the flow rate of the seawater increases, the diffusion of oxygen speeds up and the action of filming on HAl77-2 tube accelerates, resulting in decrease of corrosion rate. EN analysis shows that the flow rate of the seawater has little effect on pitting susceptivity of HSn70-1 tube; however the pitting susceptivity of HAl77-2 tube increases with increasing flow rate. Good agreement is observed between the spectral noise resistance Rsn (f) calculated from EN data and the modulus of impedance. It is shown that the electrochemical noise technique can be used in corrosion monitoring.

关键词：黄铜电子管海水腐蚀电化学阻抗光谱噪声处理

Influences of dehydrating process on properties of ATO nano-powders

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中国有色金属学会会刊：英文版 2004年第6期14卷 1123-1128页

作者：吴湘伟陈振华黄培云 School of Materials Science and Engineering Central South University Changsha 410083 China School of Materials Science and Engineering Hunan University Changsha 410083 China

Sb-doped SnO2 （ATO） nanometer powders were synthesized by hydrolysis of alkoxides, using SnCl4·5H2O and SbCl3 as raw materials. Some dehydrating processes, such as n-butanol/xylene mixed solvent heterogeneous azeotropic distillation, organic dehydrating agent and other dehydrating processes, were used to treat the wet colloids for preparing nonagglomerated ATO nanoparticles. The influences of dehydrating processes on the particle size, agglomeration and resistance were investigated using X-ray diffraction （XRD）, transmission electron microscopy （TEM） and Brunauer-Emmet-Teller （BET）. It is indicated that the dehydrating methods have great influences on the products properties, and that n-butanol/xylene mixed solvent heterogeneous azeotropic distillation processing and organic dehydrating agent can effectively remove the residual H2O molecules in wet colloids, and be used to prepare powders with high surface areas, about 85.32 m2/g, low agglomeration and good conductivity.

关键词：脱水处理纳米颗粒 ATO 二氧化锡粘结剂半导体

Sensitive determination of DNA based on resonance light scattering enhancement of azocarmine G and CTAB

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Journal of Central South University of Technology 2005年第6期12卷 688-692页

作者：陈展光任凤莲司士辉廖栩泓丁卫锋刘锦斌 School of Chemistry and Chemical Engineering Central South University Changsha 410083 China Department of Chemistry Shantou University Shantou 515063 China

A new method for the determination of DNA was developed with azocarmine G(AG) in the presence of cetyltrimethylammonium bromide(CTAB) by the resonance light scattering (RLS) technique. The synthetic samples were determined with satisfactory results, and the reaction mechanism was also studied. The results show that underthe optimum conditions, the weak RLS signal of AG can be enhanced by DNA, which results from the formation of a new ternary complex AG-CTAB-DNA with large size. Moreover, the enhanced RLS intensity at 552 nm is directlyproportional to the concentration of DNA in the range of 01.0 μg/mL for fish sperm DNA (fsDNA) and 01.5 μg/mLfor calf thymus DNA (ctDNA). Based on this, a new assay of DNA can be established. The detection limits (3σ) are 2.1 ng/mL for fsDNA and 2.2 ng/mL for ctDNA, respectively.

关键词： determination resonance light scattering azocarmine G DNA cetyltrimethylammonium bromide

Thermal debinding dynamics of novel binder system

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中国有色金属学会会刊：英文版 2001年第4期11卷 517-520页

作者：周继承黄伯云张传福刘业翔 State Key Laboratory for Powder Metallurgy Central South University Department of Metallurgical Science and Engineering Central South University

The thermal debinding dynamics of newly developed binders for cemented carbides extrusion molding was studied. It is shown that the thermal debinding processes can be divided into two stages: low temperature region, in which the low molecular mass components (LMMCs) are removed; and high temperature region, in which the polymer components are removed. The rate of thermal debinding is controlled by diffusion mechanism. The thermal debinding activation energies were solved out by differential method and integral method. The results show that the addition of other components acted as a catalyzer can effectively decrease the activation energy of thermal debinding processes.

关键词： plasticizing powder extrusion molding binder thermal debinding mechanism non isothermal dynamics