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THE SYNTHESES OF BENZOFURAN DERIVATIVES

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Journal of Wuhan University of Technology(materials Science) 2000年第4期15卷 33-37页

作者：陈连喜 biomedical materials/eng. res. ctr. Wuhan University of Technology Wuhan 430070 China

Two benzofuran derivatives were synthesized from 3,4-bis(trimethylsilyl) furan after a series of reactions. Their structures.were identified by 1H NMR, 13C NMR, MS and EA.

关键词： benzofuran synthesis 3,4-bis(trimethylsilyl)furan

Evaluation of Calcium Phosphate Cement As a Root Canal Sealer Filling Material

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Journal of Wuhan University of Technology(materials Science) 2001年第4期16卷 14-18页

作者：戴红莲 Biomed. materials and eng. res. ctr. Wuhan University of Technology Wuhan 430070 China

Calcium phosphate cement for root end sealing was obtained by in mixing alpha-tricalcium phosphate and additives with an aqueous solation of citric. Powder and liquid were mixed at a ratio of 1.25g/mL. The biocompatibility of this material was investigated primarily by subcutaneous implantation tests. Then calcium phosphate cement was used to fill three adult dogs' root canal, both calcium hydroxide paste and hydroxyapatite paste as control. The animals were killed at 4, 12, 20 weeks postoperatively res.ectively. The effects of different materials on the apical closure, res.oration of periapical tissues and adaptability to the dentinal surface were examined by optical and electr.nic microscope. The observation at 20 weeks shows that the calcium phosphate cement has the potentialities of being a root canal sealer filling material available for pulpless teeth with open-apex and destructive periapical tissue.

关键词： calcium phosphate cement histocompatibility apical closure

Study on Fine Structure of Gas Atomized LaNi_5-based Alloys

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Journal of materials Science & Technology 2003年第5期19卷 425-427页

作者： Hai JING, Hong GUO, Shuguang ZHANG, Zili MA and Shaoming ZHANGNational eng.neering res.arch Center for Non-ferrous Metals Composites, General res.arch Institute for Non-ferrous Metals, Beijing 100088, China Natl. eng. res. ctr. Res. Inst. of Non-Ferrous Metals Beijing 100088 China

The fine structure of hydrogen storage alloy powders MiNi4.3-xCoxMr0.4AI0.3(x=0.75, 0.45, 0.10; Ml: La-rich misch metal) prepared by rapidly solidifying gas atomization was investigated using a Rietveld analysis method. Two sets of CaCu5-type crystal constants were observed in the studied alloys and one set was larger than the other. With decreasing powder radius the solidification rate of powder increased, and so did the percentage of a particle part with larger crystal constants. The reason why there were two sets of crystal constants might be the difference of solidification rate between the outside and inside of a particle.

关键词： Hydrogen storage alloys Gas atomization Rietveld analysis Crystal structure

Multi-layer hierarchical cellulose nanofibers/carbon nanotubes/vinasse activated carbon composite materials for supercapacitors and electr.magnetic interference shielding

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Nano res.arch 2024年第3期17卷 904-912页

作者： Tianxu Wang Chuanyin Xiong Yongkang Zhang Bo Wang Qing Xiong Meng.ie Zhao Yonghao Ni College of Biores.urces Chemical&materials eng.neering Shaanxi University of Science and TechnologyXi’an 710021China Department of Chemical and biomedical eng.neering The University of MaineOronoME 04469USA University of New Brunswick Limerick Pulp&Paper CtrFrederictonNB E3B 5A3Canada

Developing porous self-supporting electr.des with excellent conductivity,good mechanical properties,and high electr.chemical activity is crucial for constructing electr.de materials with lightweight,ultra-thin,flexible,and high capacitance *** this work,we prepared a cellulose nanofibers(CNFs)/carbon nanotubes(CNTs)/vinasse activated carbon(VAC)(CCV)composite material with a multi-layer hierarchical conductive structure through simple vacuum filtration and *** this composite material,the self-assembly of CNF provides the main skeleton structure of a multi-layer hierarchical *** provides a fast path for the rapid transfer of electr.ns and is beneficial for the loss of electr.magnetic *** provides sufficient double layer *** synergistic effect of the above three endows CCV composite materials with excellent energy storage performance and electr.magnetic interference(EMI)shielding *** addition,we endowed the CCV composite with a certain shape and performance by introducing a vitrimer polymer with a dynamic cross-linked network *** summary,thanks to the synergistic effect of various components in the multi-layer hierarchical structure,CCV composite materials exhibit excellent integration performance,especially stable energy storage performance and EMI shielding *** significant properties make CCV composite materials have great application prospects in the fields of energy storage and intelligent EMI shielding.

关键词： self-supporting electr.des multi-layer hierarchical structure supercapacitors electr.magnetic interference shielding

Microsegregation and Improved Methods of Squeeze Casting 2024 Aluminium Alloy

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Journal of materials Science & Technology 2003年第5期19卷 413-416页

作者： Yong ZHONG, Guoyue SU and Ke YANGThe National eng.neering res.arch Center, the Institute of Metal res.arch, Chinese Academy of Sciences, Shenyang 110016, China Natl. eng. res. ctr. Inst. of Metal Res. Chinese Acad. of Sci. Shenyang 110016 China

The squeeze casting of a 2024 Al alloy was carried out to investigate the effect on microsegregation in the alloy of the application of pres.ure followed by diffusion annealing. The experimental res.lts indicate that an optimum applied pres.ure followed by an optimum diffusion annealing process can markedly reduce the degree of microsegregation and improve the mechanical properties to a degree that can approach the level of forged 2024 Al alloy.

关键词： 2024 Al alloy Squeeze casting Microsegregation Diffusion annealing

Preparation and Characteristics of Hydroxyapatite Whiskers by Homogeneous Precipitation Method

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Journal of Wuhan University of Technology(materials Science) 2001年第3期16卷 19-22页

作者：王友法 biomedical materials and eng. Center Wuhan University of Technology Wuhan 430070 China

Hydroxyapatite whilkers were prepared by the homogeneousprecipitation method. Soluble calci- um ion and phosphate ion wereused as initial materials, they were refluxed res.ectively at 85 deg.C, 90 deg. C and 95 deg. C for various leng.hs of time. A properprecipitation agent was selected to control the releasing speed ofions in the system; it induced the hydroxyapatite crystal to grow indesired way. The pH each solutions were mea- sured continuouslyduring the reaction.

关键词： Hydroxyapatite Whiskers Homogeneous Precipitation Method Hydrolysis

Development of Biomimetic Needle-like Apatite Nanocrystals by a Simple New Method

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Journal of materials Science & Technology 2004年第6期20卷 665-667页

作者： Jie WEI, Yubao LI, Yi ZUO, Xueling Peng.and Li ZHANGres.arch Center for Nano-Biomaterials, Sichuan University, Cheng.u 610064, China res. ctr. for Nano-Biomaterials Sichuan Univ. Chengdu 610064 China

A new method of calcium nitrate and sodium phosphate as reactants was employed to prepare biomimetic apatite nanocrystals by a simple heating treatment in water. The structure and properties of the apatite crystals were investigated by TEM, XRD, IR, ICP and TG. It is found that the apatite nanocrystals contain OH-, CO32-, Na+ and HPO42- ions in their crystal structure. The crystal water is removed during heating from 200℃ to 400℃. CO32-and HPO42- are decomposed at 600℃ to 800℃, also there is lattice vvater lost at this temperature stage. The morphology of the apatite nanocrystals is needle-like with a leng.h less than 80 nm. The size and crystallinity of the apatite nanocrystals increase with vvater treatment temperature and time. Compared to the apatite crystals sintered at 800℃, water treated apatite nanocrystals are poorly crystallized apatite. The res.lts indicate that the apatite nanocrystals have similarity in composition, structure, morphology and crystallinity to that of bone apatite crystals. It can be used to make apatite crystals/polymer biomimetic bone repair materials or for other biomedicai applications.

关键词： Biomimetic Apatite Nanocrystals biomedical applications

EPMA Study of the Interface of β-Tricalcium Phosphate Ceramies in Vivo

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Journal of materials Science & Technology 2004年第6期20卷 657-661页

作者： Honglian DAI, Xianying CAO, Haichen SHAO, Chunhua SHEN and Shipu LIBiomedicaI materials and eng.neering Center, Wuhan University of Technology, Wuhan 430070, China Biomed. Mat. and eng. ctr. Wuhan Univ. of Technol. Wuhan 430070 China

Electr.n probe and X-ray energy spectr.m were used to investigate the chemical composition of the interface between material and new bone after porous tricalcium phosphate ceramie implanted in tibia of rabbits. The element changes of the interface, the materials transformation and the situation of new bone formation at different implantation period were observed. The res.lts showed that the carbon element content decreased gradually in new bone tissue, and the content of calcium and phosphor element increased by degrees with the implantation time. At the same time, calcium-phosphor ratio in the new bone kept a higher Ievel. New bone grew into the materials interior, material dispersed and degraded simultaneously. Both composition of materials and new bone tended to be consentient. Finally, the materials were substituted by new bone. After implantation, not only the materials itself dissolved and degraded partially, but also new bone formed on the outer and pore surface of β-TCP porous bioceramics, which shovved that the degradation products of lifeless calcium phosphate inorganic materials took part in constituting of new bone tissue.

关键词： Calcium phosphate Electr.n probe Interface Chemical composition

Strain Softening and Hardening Behavior in AZ61 Magnesium Alloy

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Journal of materials Science & Technology 2004年第6期20卷 691-693页

作者： Haitao ZHOU, Liufa LIU, Qudong WANG, Da LU, Xiaoqin Zeng.and Wenjiang DINGNational eng.neering res.arch Center of Light Alloys Net Forming, School of materials Science and eng.neering, Shanghai Jiao Tong University, Shanghai 200030, China ctr. of Light Alloys Net Forming Sch. of Mat. Sci. and Eng. Shanghai Jiaotong Univ. Shanghai 200030 China

The deformation behavior of AZ61 Mg alloy during hot deformation has been investigated in wide temperature and strain rate range by a Gleeble simulator. Specimens are deformed in compres.ion in the temperature range of 523-673 K and at strain rates of 0.001-1 s-1. It is found that the flow curves exhibit a peak and then decrease towards steady-state of classical DRX, which decrease with rising temperature and decreasing strain rate. The deformation behavior of the specimens can be attributed to the occurrence of strain hardening and softening. As stres. decreases, the strain hardening rate declines at a fast rate when temperature rises or strain rate decreases. The shapes of θ-σ curves indicate some important features.such as subgrain formation, the criticai stres., the peak stres. and steady stres.. The onset of DRX can be determined by the point of inflection on θ-σ or Inθ-σ curves.

关键词： AZ61 Mg alloy Recrystallization Strain hardening and softening