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Biocompatibility evaluation in vitro. Part III: Cytotoxicity expression of human and animal osteoblasts on the biomaterials

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Journal of central south university 2001年第3期13卷 147-155页

作者： RUAN Jian-ming 1,M.H. Grant 2 (1. State Key Laboratory for powder metallurgy, central south university, Changs ha 410083, china 2. Bioengineering Unit, Strathclyde university, Glasgow, G4 0NW, UK) State Key Laboratory for powder metallurgy Central South University Changsha China Bioengineering Unit Strathclyde University Glasgow UK

Exclusion and inflammation in the clinic are observe d for various reas ons including material che- mical composition, physical properties as well a s macr o- and micro-structure of the implants, surface condition of the implants, and also patient dependent factors. Cytotoxicity expression of cells is a central issue i n current biocompatibility to screen the potential implant materials and drugs. This study was aimed at investigation reaction between the potential implant mat erials and surround tissue. Cytotoxicity of human and rat osteoblast in the mate rial extracts was determinated by testing standards such as GHS assay, MTT assay , alkaline phosphatase activity assay, LDH assay, and Lowry assay. research resu lts demonstrated that compared with the control condition polystyrene culture pl a te both human and rat osteoblast cells have normal phenotypic expression in hydr oxyapatite extract, and this expression was statistically restricted in hydroxya patite-spinel extract. How- ever, this restrict, e.g. cytotoxicity could be partially eliminated by immersion treatment of the materials in culture medium.

关键词： biomaterial cytotoxicity biological molecular technique

Synthesis of Lithium-cobalt Oxides by Sol-gel Method and their Cathodical Discharge Behavior at 500 ℃

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Journal of central south university 2000年第2期12卷 57-60页

作者： LI Zhi you,HUANG Bai yun,ZHU Yong li,LIU Zhi jian,QU Xuan hui (State Key Laboratory for powder metallurgy, central south university of Technology, changsha 410083, china) State Key Laboratory for powder metallurgy Central South University of Technology Changsha China

Three kinds of lithium cobalt oxides with lithium to cobalt atomic ratios of 0.6, 0.8 and 1.0 respectively were prepared using nitrates and citric acid by sol gel process. During the baking of the dry gel powder, two exothermic peaks occur, followed by the formation of Li 2O and Co 3O 4 and then the combination of LiCoO 2, which is testified by DTA and XRD. The powder formed from an alkaline sol is finer than that from the acidic one. There are a single phase intercalation of lithium ion and an electrochemical reduction reaction for higher valence cobalt ion when simulating the discharging process of Li B/LiCl KCl/lithium cobalt oxides at 500 ℃, and the voltage and specific capacity are not sensitive to the initial ratios of lithium to cobalt.

关键词： sol gel LiCoO 2 thermal battery cathode Document code:

Effects of sintering pressure and temperature on microstructure and tribological characteristic of Cu-based aircraft brake material

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中国有色金属学会会刊：英文版 2007年第4期17卷 669-675页

作者：熊翔盛洪超陈洁姚萍屏State Key Laboratory of powder metallurgy central south university State Key Laboratory of powder metallurgy Central South University

A novel Cu-based P/M aircraft brake material was prepared and the effects of sintering pressure and temperature on microstructure and tribological characteristic were investigated. For the constant sintering temperature, when the sintering pressure increases from 0.5 MPa to 1.5 MPa, the porosity, wear loss and friction coefficient decrease remarkably. When the sintering pressure increases from 1.5 MPa to 2.5 MPa, the porosity further decreases but in a little degree and wear behaviors are improved slightly. However, once the sintering pressure is larger than 2.5 MPa, it has no obvious effect on microstructure and tribological characteristic. For the constant sintering pressure, when the sintering temperature increases from 900 ℃ to 930 ℃, the sintered density remarkably increases, and wear behaviors are obviously improved. For further increasing sintering temperature to 1 000 ℃, the density keeps on increasing, but wear behaviors change slightly.

关键词：摩擦材料烧结压力烧结温度飞机制动材料铜基材料微观结构

Development and application of d30mm and d32mm drill heads

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中国有色金属学会会刊：英文版 1994年第3期4卷 106-107页

作者： Liu, Rongxiang Yi, Kaihua Pei, Xitao Wang, Wenzhao(Powdor metallurgy Factory, central south university of Technology, changsha 410083)

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ＤＥＶＥＬＯＰＭＥＮＴＡＮＤＡＰＰＬＩＣＡＴＩＯＮＯＦｄ３０ｍｍＡＮＤｄ３２ｍｍＤＲＩＬＬＨＥＡＤＳＬｉｕ，Ｒｏｎｇｘｉａｎｇ；Ｙｉ，Ｋａｉｈｕａ；Ｐｅｉ，ＸｉｔａｏＷａｎｇ，Ｗｅｎｚｈａｏ（ＰｏｗｄｏｒＭｅｔａｌｌｕｒｇｙＦａｃｔｏｒｙ，Ｃｅｎｔｒ...

关键词： small diameter drill heads development application drilling rate cost

RAPID QUENCHING AND LARGE UNDERCOOLING IN MULTISTAGE RAPID SOLIDIFICATION powder-MAKING PROCESS

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中国有色金属学会会刊：英文版 1993年第3期3卷 29-35页

作者： Chen, Zhenhua Jiang, Xiangyang Zhou, Duosan Wang, Yun Huang, Peiyun central-south university of Technology, changsha 410083, china

The rapid quenching and large undercooling phenomena and device working principle in the rapid solidification process are analyzed, and the working characteristics are presented in detail. The results show that these ... 详细信息

关键词： rapid quenching large undercooling multistage rapid salidification powder-making

Effects of cathode materials on discharge characteristics of Li B alloy/FeS_2 thermal battery

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中国有色金属学会会刊：英文版 1999年第3期9卷 530-534页

作者： Liu Zhijian(刘志坚), Duan Wei(段伟), Li Zhiyou(李志友), Huang Yinghua(黄英华) ,Qu Xuanhui(曲选辉),Huang Baiyun(黄伯云) powder metallurgy institute, central south university of Technology, changsha 410083, P.R.china  Jinzhu powder Injection Man central south Univ of Technology Changsha China

The effects of FeS 2 on the discharge characteristics of Li B alloy/FeS 2 thermal battery had been studied. Results showed that 2.5%(mass fraction)Li 2O would be needed to rule out the voltage pulse in the first part of discharge curves for the FeS 2 powder of small particle size (2 had transformed to Fe (1- x ) S where x =0.024～0.066. The deficiency of the cathode FeS 2 would make discharge voltage decrease 0.4 V. In the discharge test at high temperature (600 ℃), the discharge voltage decreased fast with the acceleration of the thermal decomposition of FeS 2.

关键词： LiB FeS 2 thermal batteries cathode effect

STRUCTURE AND FORMATION MECHANISM OF DISLOCATION NETWORKS IN TiAl^+

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Journal of central south university 1995年第1期7卷 12-15页

作者： Qu Xuanhui Huang Baiyun(powder metallurgy research institute, central south university of Technology, changsha, 410083, china)

The structure and characteristics of dislocation networks in Ti50 Al ordered alloy deformed at room temperature were studied by means of TEM diffraction contrast analysis technique. The results show that the observed... 详细信息

关键词： ordered alloy intermetallic compound dislocation networks TEM ductility/TiAl titanium aluminide

Effect of Nd_2Fe_(14)B/α-Fe Nanocomposite Permanent Magnets with a Combined Co and Nb Additions

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Journal of Wuhan university of Technology(Materials Science) 2009年第5期24卷 725-727页

作者：马瑞 School of Materials Science and metallurgy Engineering Guizhou University

Influence of Co＋Nb on the Nd8Fe82Co3Nb1B6 nanocomposite magnets was investigated by adding Co element combined with Nb element. Results show that the high temperature stability of two phases is increased. Adding Co＋Nb could improve the glass forming ability of the alloy, reduce the size of grains, increase the exchange coupling ability of two phases, and obviously increase the magnetic properties of the alloy. The optimal magnetic properties are Br=1.14 T, Hcj=320 kA/m, （BH）max=109.3 kJ/m^3

关键词： nanocomposite permanent magnets glass forming ability exchange coupling ability magnetic properties

Activity Enhancement of Vanadium Catalysts with Ultrasonic Preparation Process for the Oxidation of Sulfur Dioxide

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Journal of Natural Gas Chemistry 2003年第2期12卷 139-144页

作者： Zhenxing Chen, Honggui Li, Lingsen WangState Key Laboratory for powder metallurgy, College of Chemistry and Chemical Engineering, central south university, changsha 410083, china State Key Laboratory for powder metallurgy College of Chemistry and Chemical EngineeringCentral South University Changsha 410083 China

The effect of ultrasonic cavitations on the activity of vanadium catalysts atlow temperatures for the oxidation of sulfur dioxide, in which refined carbonized mother liquor hadbeen added, was investigated. Twenty minutes were needed to produce obvious cavitations when thecatalyst raw material was treated in the 50 W ultrasonic generator. However, only 10 minutes wouldbe needed in a 150 W ultrasonic generator. The higher the temperature of the wet material, the lesstime was needed to produce cavitations, and the optimal temperature was 60℃. The water content inthe wet material mainly affected the quantity of cavitations. Ls-8 catalyst was prepared usingultrasonic. Its activity for conversion of SO_2 reached to 52.5% at 410℃ and 4.2% at 350℃. Thedifferential thermal analyses indicate that both endothermic peaks and exothermic peaks noticeablyshifted forward compared with Ls catalyst prepared without ultrasonic, and SEM results show auniform pore size distribution for Ls-8 catalyst.

关键词： ultrasonic dispersion vanadium catalyst low temperature activity sulfurdioxide cavitation