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Large Magnetostriction from Morphotropic Phase Boundary in Ferromagnets

Physical Review Letters 2010年第19期104卷 197201-197201页

作者： Sen Yang Huixin Bao Chao Zhou Yu Wang Xiaobing Ren Yoshitaka Matsushita Yoshio Katsuya Masahiko Tanaka Keisuke Kobayashi Xiaoping Song Jianrong Gao Multi-disciplinary Materials Research Center Frontier Institute of Science and Technology State Key Laboratory for Mechanical Behavior of Materials and MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter Xi’an Jiaotong University Xi’an 710049 China Ferroic Physics Group National Institute for Materials Science Tsukuba 305-0047 Ibaraki Japan National Institute for Materials Science Beamline BL15XU Spring-8 1-1-1 Kohto Sayo-cho Hyogo 679-5148 Japan Key Lab of Electromagnetic Processing of Material Northeastern University 3-11 Wenhua Road Shenyang 110004 China

For more than half of a century, morphotropic phase boundary (MPB) in ferroelectric materials has drawn constant interest because it can significantly enhance the piezoelectric properties. However, MPB has been studied merely in ferroelectric systems, not in another large class of ferroic systems, the ferromagnets. In this Letter, we report the existence of an MPB in a ferromagnetic system TbCo2−DyCo2. Such a magnetic MPB involves a first-order magnetoelastic transition, at which both magnetization direction and crystal structure change simultaneously. The MPB composition demonstrates a 3–6 times larger “figure of merit” of magnetostrictive response compared with that of the off-MPB compositions. The finding of MPB in ferromagnets may help to discover novel high-performance magnetostrictive and even magnetoelectric materials.

关键词： Ferromagnetism

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Cyanobacteria immobilised in porous silica gels: Exploring biocompatible synthesis routes for the development of photobioreactors

Cyanobacteria immobilised in porous silica gels: Exploring b...

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作者： Léonard, Alexandre Rooke, Joanna C. Meunier, Christophe F. Sarmento, Hugo Descy, Jean-Pierre Su, Bao-Lian 61 rue de Bruxelles B-5000 Namur Belgium 61 rue de Bruxelles B-5000 Namur Belgium State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology 122 Luoshi Road Wuhan 430070 China Fonds National de la Recherche Scientifique 5 rue d'Egmont B-1000 Brussels Belgium Fonds National de la Recherche Scientifique B-1000 Brussels Belgium Institut de Ciències Del Mar-CMIMA CSIC Departament de Biologia Marina i Oceanografia Pg Maritim de la Barceloneta 37-49 E08003 Barcelona Catalunya Spain

With the aim of designing photobioreactors (PBR) based on a smart exploitation of microalgae for the production of biofuels and metabolites of interest, this paper describes a novel approach where cyanobacteria are entrapped within highly porous silica matrices. With this concept, it would be possible to work with a constant population of organisms for a continuous (and increased) photoproduction of metabolites, in contrast to "one-shot" uses of liquid cultures. Different hybrid materials based on porous silica gels are described with a special emphasis on finding the most appropriate immobilisation conditions for prolonged cell survival. It is found that an aqueous route based on acid-exchanged sodium silicate combined with the use of silica nanoparticles as a gel-strengthening species shows the best results with a high primary production rate post immobilisation and a preservation of the photosynthetic pigments of up to 35 weeks. Oxygen production, though very low, could be evidenced up to 17 weeks after entrapment, demonstrating the suitability of using porous silica matrices in PBR design. © 2010 The Royal Society of Chemistry.

关键词： Metabolites

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Promotion of catalytic activity for methanol electro-oxidation on CoPc-Pt/C co-catalysts

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Chinese Science Bulletin 2009年第6期54卷 1032-1036页

作者： WU JingJie XU YiMin PAN Mu MA WenTao TANG HaoLin State Key Laboratory of Advanced Technology for Materials Synthesis and Progressing Wuhan University of Technology Wuhan 430070 China

The catalytic activity for methanol electro-oxidation on CoPc-Pt/C co-catalysts, prepared by impregna-tion method, was studied in details through electrochemical methods. Cyclic voltammetry (CV) result demonstrates that CoPc has higher forward anodic peak current density and jf / jb value (forward anodic peak current density/backward anodic peak current density) than Pt/C. Chronoamperometry (CA) analysis indicates that CoPc-Pt/C exhibits both excellent transient current density and stable current density for methanol electro-oxidation compared with Pt/C. Two main mechanisms related to the pro-motion of catalytic activity are as follows: CoPc-Pt/C has the activity of tolerance to carbonaceous in-termediates, thus inhibiting the self-poisoning of catalysts; CoPc-Pt/C owns prominent intrinsic cata-lytic activity indicated by the apparent activation energy for methanol oxidation on CoPc-Pt/C, which is 18 kJ/mol, less than that on Pt and PtRu catalysts as reported.

关键词：甲醇电氧化催化活性酞菁钴催化剂铂电流密度炭合作

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Edge extraction algorithm for dual bypass GMAW weld pool

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Shanghai Jiaotong Daxue Xuebao/Journal of Shanghai Jiaotong University 2010年第SUPPL. 1期44卷 4-7页

作者： Xue, Cheng Shi, Yu Fan, Ding Li, Wei-Dong Key Laboratory of Non-Ferrous Metal Alloys and Processing Lanzhou University of Technology Lanzhou 730050 China State Key Laboratory of Gansu Advanced Non-Ferrous Metal Materials Lanzhou University of Technology Lanzhou 730050 China

In order to study the process of aluminum alloy dual bypass gas metal arc welding (DB-GMAW), a series of weld pool images were acquired by a passive vision system. The principle and every part of its system were introduced. And differential operators, such as Roberts, Sobel, Prewitt, LOG, Canny and Zerocross, were used to extract the edge of weld pool from acquired images. The results show that the base metal current is decreased greatly because of the bypass arc, and the brightness of arc above the weld pool is decreased too. That makes getting and processing the weld pool images easier. In the six edge extraction results of differential operators, the Canny operator can get a continuous, whole and exact edge. This will be useful for DB-GMAW process control.

关键词： Gas metal arc welding

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High-speed welding technology analysis of double electrode GMAW

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Shanghai Jiaotong Daxue Xuebao/Journal of Shanghai Jiaotong University 2010年第SUPPL. 1期44卷 50-53页

作者： Shi, Yu Xue, Cheng Zhong, Hao Fan, Ding State Key Laboratory of Gansu Advanced Non-Ferrous Metal Materials Lanzhou University of Technology Lanzhou 730050 China Key Laboratory of Non-Ferrous Metal Alloys and Processing Lanzhou University of Technology Lanzhou 730050 China

The principle of double electrode gas metal arc welding (DE-GMAW) and all parts of its welding system were introduced. The arc pressure and heat of base metal were both reduced because the bypass arc separated a part of weld current which through the wire. It is good for the high-speed welding process. The high-speed welding result of DE-GMAW was contrasted with that of traditional GMAW. The result showed that DE-GMAW could have a higher welding speed and a better weld formation than the traditional GMAW under a same weld current.

关键词： Gas metal arc welding

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Intergranular corrosion and pitting corrosion resistances of Ni-Cr-Mo-Cu-Mx alloys

Beijing Keji Daxue Xuebao/Journal of University of Science a...

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Beijing Keji Daxue Xuebao/Journal of University of Science and technology Beijing 2010年第4期32卷 461-465页

作者： Yang, Rui-Cheng Niu, Shao-Rui Li, Zhi Jin, Sai-Te State Key Laboratory of Gansu Advanced Non-ferrous Metal Materials Lanzhou University of Technology Lanzhou 730050 China Key Laboratory of Non-ferrous Metal Alloys and Processing Lanzhou University of Technology Lanzhou 730050 China

Ni-Cr-Mo-Cu-Mx nickel-base corrosion-resistant alloys were prepared by adding Ti and Fe with a manual electro-arc furnace. Intergranular corrosion and pitting corrosion resistances of these alloys were investigated by chemical erosion and electrochemical corrosion techniques (polarization curve methods and cyclic voltammetry). The results showed that the intergranular corrosion resistance of the alloys added Ti increased and the pitting corrosion resistance decreased. Fe addition deteriorated the intergranular corrosion resistance of Ni-Cr-Mo-Cu alloys but improved the pitting corrosion resistance. The electrochemical behaviors and characteristics of intergranular corrosion and pitting corrosion coincided with the results of chemical erosion.

关键词： Pitting

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Densification of in situ prepared mesocarbon microbead/carbon nanotube composites by hot-press sintering

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中国有色金属学会会刊：英文版 2009年第3期19卷 646-651页

作者：吴彬巩前明吴建军宋怀河梁吉 Department of Mechanical Engineering Tsinghua University Key Laboratory for Advanced Materials Processing Technology of Ministry of Education Tsinghua University State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology

In situ prepared mesocarbon microbead/carbon nanotube(MCMB/CNT) composites are potential precursors of high density carbon materials for various applications. Integrated MCMB/CNT composites were successfully fabricated by hot-press sintering at 550 ℃ under 30 MPa. After further calcination at 900 ℃, the hot-press sintering fabricated MCMB block has an apparent density of 1.77 g/cm3 and the open porosity 5.1%. With the addition of 5%(mass fraction) CNTs, the density of the composite block is elevated to 1.84 g/cm3, and its open porosity is reduced to 3.5%. The flexural strength of composite block with 5% CNTs is elevated to 116 MPa. Through the hot-press sintering, pores of 10-50 nm in the calcinated bulks are remarkably eliminated. The interstice between microbeads in the composite blocks is filled up by CNTs together with β-resin and quinoline-insoluble spheres, which can further contribute to the densification.

关键词：碳纳米管复合材料中间相炭微球热压烧结原位制备致密化复合砌块孔隙率表观密度

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Deformation behavior of Cu-12wt%Al alloy wires with continuous columnar crystals in dieless drawing process

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Science China(Technological Sciences) 2009年第8期52卷 2232-2236页

作者： LIU XueFeng WU YuHui XIE JianXin Key Laboratory of Advanced Processing Technology of Materials of Ministry of Education University of Science and Technology BeijingBeijing 100083China State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China

The microstructure and mechanical properties of Cu-12wt%Al alloy wires which are composed of continuous columnar crystals after dieless drawing forming at drawing speed of 1.0–1.4 mm/s and deformation temperature of 600–900°C were analyzed, and deformation behavior of the alloy during dieless drawing forming was experimentally investigated. The results showed that in the above-mentioned conditions, recrystallization phenomenon was not found during dieless drawing forming. When a drawing speed of 1.0 mm/s was used, the grain boundaries were out of straight gradually with increasing deformation temperature from 600°C to 900°C, and tensile strength of the dieless drawn Cu-12wt%Al alloy wires increased while elongations decreased with increasing deformation temperature. At drawing speed of 1.1–1.2 mm/s and deformation temperature of 600°C, the effect of dieless drawing forming process on the microstructure of the alloy was inconspicuous, and when drawing speed was up to 1.3–1.4 mm/s, the grain boundaries of continuous columnar crystals became zigzag while there was little effect of drawing speed of 1.1–1.4 mm/s on the elongation and tensile strength of the alloy wires.

关键词： Cu-Al alloy continuous columnar crystals dieless drawing microstructure and mechanical properties

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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 advanced technology for materials synthesis and processing, Wuhan 430070, China 2 School of materials Science and Engineering, Wuhan University of technology, Wuhan 430070, China 3 Biomedical materials Research Center, Wuhan University of technology, Wuhan 430070, China State Key Laboratory of Advanced 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

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Effect of Ultrafine Grinding on Dissolving-out Quantity of Tanshinone IIA from Radix Salvia Miltiorrhiza

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Journal of Wuhan University of technology(materials Science) 2009年第6期24卷 973-976页

作者：苏艳丽傅正 College of Chemistry Chemical Engineering and Material ScienceSoochow UniversitySuzhou China State Key Laboratory of Advanced Technology for Material Synthesis and Processing Wuhan University of Technology

In order to improve the bioavailability, Radix salvia miltiorrhiza raw powder mixed with distilled water （5.5wt%） was ultrafinely ground to nanosize particles using HSCS pulverizer, and the dissolving-out quantity of tanshinone IIA in the filtrate that obtained from nanoparticles suspension and raw powder marinated in water for different time was determined by HPLC. The experimental results show that raw powder can be ultrafinely ground to 133.5 nm at 1500 r/min for 50 min and the molecular structure of active ingredients doesnot change, and the dissolving-out quantity of tanshinone IIA obtained from the filtrate is increased greatly from 12.77 μg/g to 54.55 μg/g.

关键词： Radix salvia miltiorrhiza tanshinoe IIA HPLC dissolving-out quantity

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