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XPS Analysis of Ni and Oxygen in Single-Sintered SrTiO_3.Multifunction Ceramic

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Journal of materials science & Technology 2001年第5期17卷 535-537页

作者： Qing XU, Wen CHEN and Runzhang YUAN state key laboratory of {3. Technology for materials synthesis and processing, wuhan university of Technology, wuhan 43.070, china wuhan Univ Technol State Key Lab Adv Technol Mat Synth & Proc Wuhan 430070 Peoples R China

XPS analyses have been performed to investigate the chemical conditions of Ni and oxygen on grain surfaces in single-sintered SrTiO3.capacitor-varistor ceramic doped with Nb2O5 and NiO. It is ascertained that Ni is in form of Ni2+ ions, which substitute for Ti4+ ions on grain surfaces during the oxidizing annealing. Moreover, it is confirmed that three kinds of chemically adsorbed oxygen such as O2-, O- and O-2(-) are formed on grain surfaces. It is proposed that these behaviors contribute greatly to the generation of multiple types of grain boundary acceptor states in the ceramic.

关键词： XPS Analysis of Ni and Oxygen in Single-Sintered SrTiO3.Multifunction Ceramic Ni

Dominant point detecting based non-uniform B-spline approximation for grain contour

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science china(Technological sciences) 2007年第1期50卷 90-96页

作者： ZHAO XiuYang1, YIN YanSheng1,2 & YANG Bo3.1 Shandong key laboratory of Engineering Ceramics, Shandong university, Jinan 250061,{3. 2 School of materials, Ocean university of{3., Qingdao 266003.{3. 3.state key laboratory of advanced Technology for materials {13. and processing, wuhan university of science and Technology, wuhan 43.070,{3. 1. Shandong key laboratory of Engineering Ceramics Shandong University Jinan 250061 China 2. School of materials Ocean University of China Qingdao 266003 China 3. state key laboratory of {3. Technology for materials synthesis and processing Wuhan University of Science and Technology Wuhan 430070 China

Three-dimension reconstruction from serial sections has been used in the last decade to obtain information concerning three-dimensional microstructural ge-ometry. One of the crucial steps of three-dimension reconstruction is getting compact and fairing grain contours. Based on the achievement of closed raw con-tours of ceramic composite grains by using wavelet and level set, an adaptive method is adopted for the polygonal approximation of the digitized raw contours. Instead of setting a fixed length of support region in advance, the novel method computes the suitable length of support region for each point to find the best es-timated curvature. The dominant points are identified as the points with local maximum estimated curvatures. Periodic closed B-spline approximation is used to find the most compact B-spline grain boundary contours within the given tolerance. A flexible distance selection approach is adopted to obtain the common knot vector of serial contours consisting of less knots that contain enough degrees of freedom to guarantee the existence of a B-spline curve interpolating each contour. Finally, a B-spline surface interpolating the serial contours is generated via B-spline surface skinning.

关键词： composite B-spline dominant points control points grain contour

Research on Ultrafine Tungsten Carbide-Cobalt(WC-Co) Cemented Carbide Rods of Miniature Drills for Highly Integrated Printed Circuit Board(PCB)

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Journal of materials science & Technology 2005年第3期21卷 353-356页

作者： Xiaoliang SHI, Gangqin SHAO, Xinglong DUAN and Runzhang YUAN state key laboratory of {3. Technology for materials synthesis & processing, wuhan university of Technology, wuhan 43.070, china Lab. of advanced Technology for materials synthesis and {3. Wuhan University of Technology Wuhan 430070 China

Nanocrystalline tungsten carbide-cobalt (WC-Co) composite powders produced through spray thermal decomposition-continuous reduction and carburization technology were used to prepare φ3.25 mm×3. mm ultrafine tungsten carbide-cobalt (WC-Co) cemented carbide rods through vacuum sintering plus sinterhip technology. The microstructure, Vickers hardness, density and Rockwell A hardness (HRA), transverse rupture strength (TRS), saturated magnetization and coercivity force were tested. The results show that the average grain size of the sintering body prepared through vacuum sintering plus sinterhip technology was 43. nm; transverse rupture strength (TRS) was 3.50 MPa; Vickers hardness was 1890 and Rockwell A hardness of sintering body was 93. High strength and high hardness ultrafine WC-Co cemented carbide rods used to manufacture printed circuit board (PCB) drills were obtained.

关键词： Nanocrystalline Composite powder Cemented carbide Rods

Mold Filling Analysis in Vacuum Infusion Molding Process Based on a High-Permeable Medium

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Journal of materials science & Technology 2003年第5期19卷 467-471页

作者： Yingdan ZHU, Hua TAN and Jihui WANGstate key laboratory of {3. Technology for materials synthesis and processing, wuhan university of Technology, wuhan 43.070, china state key laboratory of {3. Technology for materials synthesis and processing Wuhan University of Technology Wuhan 430070 China

The objective of this paper is to understand the flow mechanism through visualization experiments and discuss theinfluence of process parameters on mold filling process. A 2D leakage flow model is developed to simulat... 详细信息

关键词： Vacuum infusion molding process (VIMP) High-permeable medium Mold filling Simulation

The Impact of Annealing Temperature on the Optical Performance of Cr-Cr_2O_3.Produced by Plasma Spraying as Solar Energy Selective Absorber Coating

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稀有金属材料与工程 2012年第S1期41卷 315-318页

作者： Gong Dianqing,Cheng Xudong,Wang Ke state key laboratory of {3. Technology for materials synthesis and processing,wuhan university of Technology,wuhan 43.070,china wuhan Univ Technol State Key Lab Adv Technol Mat Synth & Proc Wuhan 430070 Peoples R China

A series of selective solar absorber coatings of Cr-Cr2O3.were deposited in different content on stainless steel by plasma *** samples were annealed at different *** optical performance(both the solar absorptance and the thermal emittance)were studied by *** surface morphology,the structure and the surface roughness were investigated by scanning electron microscopy(SEM),X-ray diffraction(XRD),and roughmeter *** results show that,as the content of Cr increased,the solar absorptance(α)decreased greatly,from 0.91 to ***,the thermal emittance(ε) decreased more greatly,from 0.86 to about *** ratio between the solar absorptance and the thermal emittance increased from 1.06 to *** had a great impact on the optical *** temperature is an important *** its influence was a little *** pure Cr coating,annealing at 500℃ was a perfect chosen,where the ratio between the solar absorptance and the thermal emittance was highest of 1.46.

关键词： optical performance plasma spraying solar energy selective absorber coating

Fabrication of Ti_2AlC by Spark Plasma Sintering from Elemental Powders and Thermodynamics Analysis of Ti-Al-C System

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Journal of wuhan university of Technology(materials {3.) 2007年第2期22卷 325-328页

作者：王苹 state key laboratory of {3. Technology for materials synthesis and processing Wuhan University of Technology

A ternary-layered carbide Ti2AlC material could be synthesized by spark plasma sintering（SPS） technology using elemental powder mixture of Ti, Al and active carbon. By means of XRD and SEM, phases were identified and microscopically evaluated. The experimental results show that the main phase in the product was fully crystallized Ti2AlC with small particle size when sintered at 1200℃. The synthesis temperature of SPS was 200-400℃ lower than that of hot pressing （HP） or hot isostatic pressing （HIP）. Through thermodynamics calculations, the mechanism of Ti2AlC was studied by calculating changes of Gibbs free energy of reactions.

关键词： Ti2AlC spark plasma sintering elemental powder thermodynamics analysis

Sandwich Magnetoelectric Composites of Polyvinylidene Fluoride,Tb-Dy-Fe Alloy,and Lead Zireonate Titanate

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Journal of wuhan university of Technology(materials {3.) 2007年第4期22卷 596-599页

作者：赵广辉熊传溪 state key laboratory of {3. Technology for materials synthesis and processing School of Computer science and Technology Wuhan University of TechnologyWuhan 430070China School of materials science and Engineering Wuhan University of TechnologyWuhan 430070China

The novel sandwich composites were prepared by sandwiching a polyvinylidene fluoride/Tb- Dy-Fe alloy composite （PVDF/Terfenol-D） between polyvinylidene fluoride/lead zirconate titanate composites （PVDF/PZT）. The maximum magnetoelectric effect voltage coefficient, （dE/dn）3.max, of the sandwich composites is higher than that of three-phase composites at their own optimal loading level of Terfenol-D. This is attributed to less interface relaxations of strain and better polarization of the sandwich composites. When the volume fraction of Terfenol-D is higher than 0.10, no coupling interaction for three-phase composites could be observed, but （dE/dn）3.max of sandwiched composites still reached 20 mV/（***）. At high magnetic field intensity, the magnetoelectric effect voltage coefficient, （dE/dn）3., of sandwich composites is higher than that of three-phase composites; at low magnetic field intensity, （dE/dn）3. of sandwich composites is lower than that of three-phase composites. At their resonance frequency, the （dE/dn）3.max of the sandwich composites and the three phase composites are 150 mV/（***） and 42 mV/（cmoOe）, respectively. This significant increase of （dE/ dn）3.max at resonance frequency confirms the improvement of maximum magnetoelectric effect coefficient via sandwich-structured composites.

关键词： magnetoelectric piezoelectric sandwiched composites

Phenomenon of “contact guidance” on the surface with nano-micro-groove-like pattern and cell physiological effects

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Chinese science Bulletin 2009年第18期54卷 3200-3205页

作者： ZHOU Feng 1,2, YUAN Lin 1,3. HUANG He 1,2 & CHEN Hong1,2 1 state key laboratory of {3. Technology for materials synthesis and processing, wuhan 43.070, china 2 School of materials science and Engineering, wuhan university of Technology, wuhan 43.070, china 3.Biomedical materials Research Center, wuhan university of Technology, wuhan 43.070, china state key laboratory of {3. Technology for materials synthesis and processing Wuhan 430070 China School of materials science and Engineering Wuhan University of Technology Wuhan 430070 China Biomedical materials Research Center Wuhan University of Technology Wuhan 430070 China

The topography of material surface has important influence on cell behavior and physiological functions. Groove-like pattern has drawn much attention among various patterns, due to the phenomenon of "contact guidance" induced by this kind of topography. This review mainly focuses on "contact guidance" formation as well as its influence on cell behavior and physiological effects. The possible mechanisms of "contact guidance" formation were discussed. The research trend and the potential applications were also suggested.

关键词：细胞行为生理功能材料表面逻辑效应触指纳米微米生理效应

Fractal Analysis of Gas Diffusion Layer in PEM Fuel Cells

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Journal of wuhan university of Technology(materials {3.) 2006年第1期21卷 22-25页

作者：石英肖金生 state key laboratory of {3. Technology for materials synthesis and processing Wuhan University of Technology Wuhan 430070ChinaSchool of Automation Wuhan University of Technology Wuhan 430070 China state key laboratory of {3. Technology for materials synthesis and processing Wuhan University of Technology Wuhan 430070ChinaSchool of Automotive EngineeringWuhan University of Technology Wuhan 430070China

The aim of this study is to show how fractal analysis can be effectively used to characterize the texture of porous solids. The materials under study were carbon papers, the backing material of the gas diffusion layer （GDL） in Proton Exchange Membrane Fuel Cell （PEMFC）. The fractal dimensions were calculated by analyzing data from mercury porosimetry. The polytotrafluoroethylene （PTFE） treated carbon paper shows a significantly high fractal dimension value than pare sample, and the high fractal dimension signifies that the physical complexity of the pore surface is enhanced. The fractal dimension can be used as a valid parameter to monitor the textural evolution of the samples as the treatment progresses, as this behaves in a similar way to other textural parameters. The use of fractal analysis in conjunction with the results of classical characterization methods leads to a better understanding of textural modificatious in the processing of materials.

关键词： PEMFC gas diffusion layer fractal dimension mewury porosimetry