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Pyroelectric spectrum in Pb(zr,Sn,Ti)O3 antiferroelectric- ferroelectric ceramics

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Chinese Science Bulletin 2000年第13期45卷 1169-1172页

作者： Feng, YJ Xu, z yang, TQ Yao, X Xian Jiao Tong Univ Elect Mat Res Lab Xian 710049 Peoples R China

The pyroelectric effect of phase transition induced with temperature in Nb-modified Pb(zr,Sn,Ti)O3 antiferroelectric-ferroelectric ceramics is studied. Experimental results reveal that the phase transitions are accompanied with marked pyroelectric peaks, there exists the close relation between the type of phase transition and the shape of pyroelectric peak. Because of the variations of phase transition, various pyroelectric spectra result. The pyroelectric spectrum can display the polarization effect and some inferior phase transitions with temperature variations, such as antiferroelectric AFEA-AFEB or ferroelectric FEL-FEH transition, which are not detected by the conventional dielectric measurement.

关键词： Pb(zr Sn Ti)O3 ceramics pyroelectric spectrum temperature-induced phase transition.

Fabrication and Characterization of a 2×2 Microfiber Knot Resonator Coupler

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Chinese Physics Letters 2012年第8期29卷 96-98页

作者： A.A.Jasim A.z.zulkifli M.z.Muhammad H.Ahmad S.w.Harun Department of Electrical Engineering University of Malaya 50603 Kuala LumpurMalaysia Photonics Research Center Department of PhysicsUniversity of Malaya50603 Kuala LumpurMalaysia

A 2×2 microfiber knot resonator(MKR)coupler is *** hybrid device is obtained by forming a knot within the coupling region of a microfiber coupler with a 50:50 splitting *** microfiber coupler is successfully fabricated by laterally fusing and tapering two optical fibers using a flame-brushing *** coupler has an overlapping length of 40 mm with a uniform waist of around 5μ*** an MKR structure,the coupler produces a resonant response at both output *** free spectral range of the output spectrum from both ports is obtained at 0.2 nm at a knot diameter of 260μ*** resonance extinction ratio of the device varies from 2 to 6 dB while the calculated Q factor and finesse are~25646 and 3.3,respectively,at both output ports.

关键词： technique fiber resonator

OXIDATION BEHAVIOR OF KOVAR ALLOY IN CONTROLLED ATMOSPHERE

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Acta Metallurgica Sinica(English Letters) 2008年第6期21卷 409-418页

作者： D. w. Luo z.S. Shen School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

Controlled oxidation experiments were performed on Kovar alloy by changing oxidation atmosphere, temperature, and exposure time to produce films with different oxide type and thickness. The results indicated that single Fe3O4 and single FeO were respectively obtained when Kovar alloy was oxidized in N2-2.31%H2O-0.95%H2 at 500℃ and in N2-2.31%H2O-0.5%H2 at 1000℃, and all kinetic curves followed linear relation; mixed oxides of FeO and Fe3O4 formed when Kovar was oxidized in N2-2.31%H2O at 1000℃and parabolic kinetics were obeyed. Analysis of metallographic cross section of oxides indicated that oxygen diffusion inward through the oxide scale is responsible for intergranular oxide, which had formed beneath the oxide scales when the oxide products were mixed oxides of FeO and Fe3O4, and which did not occur when the oxide was single FeO or Fe3O4. The oxidation model was also established.

关键词： Kovar alloy, Oxidation Controlled atmosphere H2-H2O-N2

STUDY ON THE CORROSION AND MECHANICAL PROPERTIES OF FJ316 STAINLESS STEEL-GLASS COMPOSITE

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Acta Metallurgica Sinica(English Letters) 1998年第3期11卷 175-182页

作者： S.Abubakir Y.S.wu T.C.zhang z.yang z.zhang Univ of Science and Technology Beijing Beijing China

Samples of FJ316 stainless steel powder alloyed with different amounts of glass2 material have been compacted at the pressure of 686MPa and sintered at 1160, 1180,and 1200℃, in hydrogen atmosphere for one hour. The materials have been subjected to microstructure characterization, tensile strength, handness, impact toughness and corrosion testing. The effect of the experimental process parameter has been evaluated and the importance of porosity, sintered temperature, glass content and its grain size in determining mechanical and corrosion properties has been confirmed. Glass has a strong effect on the mechanical properties and produces brittleness when added to FJ316SS. Very good corrosion resistance has been achieved by comparing this result with the corosion resistance of sintered pure stainless steel. The results of this study permit optimization in the production of glass alloyed P/M FJ316SS, with respect to mechanical properties and high corrosion resistance.

关键词： corrosion rate FJ316SS glass2 composite material mechanical property

The Novel Mechanical Property of Tongue of a woodpecker

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Journal of Bionic Engineering 2009年第3期6卷 214-218页

作者： P zhou X Q Kong C w wu z Chen National Key Laboratory for Structural Analysis of Industrial Equipment Dalian University of Technology Department of Civil and Environmental Engineering University of Missouri

Biomaterials such as bone,teeth,nacre and silk are known to have superior mechanical properties due to their specific nanocomposite *** we report that the woodpecker's tongue exhibits a novel strength and flexibility due to its special composite micro/*** tongue consists of a flexible cartilage-and-bone skeleton covered with a thin layer tissue of high strength and *** the interface between the cartilage-and-bone skeleton and the tissue layer,there is a hierarchical fiber-typed *** is this special design of the tongue that makes the woodpeckers efficient in catching the insects inside *** special micro/nanostructures of the woodpecker's tongue show us a potential method to enhance the interfacial connection between soft and hard material layers for bio-inspired composite system designs.

关键词： woodpeckcr hyoid cartllage multilevel structure tensile strength

Mesoporous Carbon-Tin Nanocomposites as Anode Materials for Li-ion Battery

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Journal of Materials Science & Technology 2008年第4期24卷 657-660页

作者： z. w.zhao z.P.Guo P. Yao H.K.Liu Institute for Superconducting and Electronic Materials University of Wollongong NSW 2522 Australia ARC Centre of Excellence for Electromaterials Science University of Wollongong NSW 2522 Australia Centre for Analysis and Measurement Tianjin University Tianjin 300072 China

A new mesoporous carbon-tin （MC-Sn） nanocomposite has been successfully prepared via a two-step method. From the transmission electron microscopy （TEM） observations, the tin nanoparticles were decorated on the as-prepared mesoporous carbons. The mesoprous structure of the carbon can effectively buffer the volume changes during the Li-Sn alloying and de-alloying cycles. The as-prepared MC/Sn nanocomposite electrodes exhibited extremely good cycling stability, with the specific capacity of Sn in the composite electrode calculated to be 959.7 mAh-g-1, which amounts to an impressive 90.9% of the theoretical value （990 mAh-g-1）. The reversible capacity after 200 cycles is 96.1% of the first cycle reversible capacity, i.e., the capacity fade rate is only 0.0195% per cycle, which is even better than that of commercial graphite-based anodes.

关键词： Mesoporous Carbon Tin Nanocomposites Lithium ion battery

Photoluminescence of Nanometer SiC Powder

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Journal of Materials Science & Technology 1997年第4期13卷 333-335页

作者： yang, XC Han, GR zhang, XB Du, PY Ding, zS zhang, z zHEJIANG UNIV DEPT MAT SCI & ENGNHANGZHOU 310027PEOPLES R CHINA CHINESE ACAD SCI BEIJING ELECTRON MICROSCOPE CTRBEIJING 100080PEOPLES R CHINA

Photoluminescence of nanometer SiC powder was found firstly. By TEM, SAED, FTIR and chemical analyses, it is suggested that the quantum confinement effect of nanometer beta-SiC be responsible for the blue light and vi... 详细信息

关键词： Nanostructured materials

3-Blocks with Abelian Defect Groups Isomorphic to z3m × z3n

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Acta Mathematica Sinica,English Series 2013年第12期29卷 2245-2250页

作者： Sheng yang Department of Mathematics Wenzhou University

Let G be a finite group and let p be a fixed prime number. Let B be a p-block of G with defect group D. In this paper, we give results on 3-blocks with abelian defect groups isomorphic to z3m ×z3n. we are particularly interested in the number of irreducible ordinary characters and the number of irreducible Brauer characters in the block. we calculate two important block invariants k（B） and l（B） in this case.

关键词： Blocks defect groups inertial quotient inertial index

STRUCTURE AND PROPERTIES OF RE-Ni-B-Al_2O_3 COATING MATERIAL

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Acta Metallurgica Sinica(English Letters) 1997年第1期10卷 56-60页

作者： z.C Guo X.w yang, H.K Lin, z.Y wang and M. wang(Department of Metallurgy, Kunming University of Science and Technology Kunming 650093, China) Kunming Univ of Science and Technology Kunming China

The effects of heat treatment temperature on the hardness, wear resistance and structure of a coating material consisting of Ni-0.45wt% RE4.8wt% B-6.2wt% Al2O3 have been discussed. The results showed that the hachess and wear resistance of the composite material reach the optimal values when heating temperature rises to 350℃ and 500℃ respectivelg. X-ray diffraction and scanning electron microscopy indicate that the composite material is amorphous in the as-coating state. The crystallized temperature of Ni-B alloy is increased when RE and Al2O3 particles are inserted. The hardness and wear resistance of the composite are raised obviously with addition of RE and Al2O3 particles.

关键词： RE-Ni-B-Al_2O_3 composite material amorphous structure