ZHANG Cheng HU Zhuangqi GE Yunlong WANG Yongzhong QIAO Guiwen Institute of Metal Research
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Academia Sinica
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Shenyang
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China doctorate student Institute of Metal Research
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Academia Sinica
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Shenyang 110015
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China
金属学报(英文版)
The Bi_2(Sr,Ca)_3Cu_2O_x system superconductor was prepared by different melting procedures and after treatment.The effects of cooling rate,annealing temperature and time,as well as melting procedures on phase transformation were investigated.The structure and properties were examined by X-ray diffraction,optical microscopy,EPMA,DTA,TGA and measurements of electric and magnetic properties.When the melt of nominal composition Bi_2(Sr,Ca)_3Cu_2O_x solidified in air,the Bi_2(Sr,Ca)_3Cu_2O_(8+δ)(2212)superconducting phase is stable,the easily solidified product including Bi_2(Sr,Ca)_2CuO_(6+δ)(2201)phase is metastable, and another may be amorphous if rapidly quenched.The last two may transform into 2212 phase by after treatment at an optimal annealing temperature ranging 780—870℃.While 2201 phase,prepared by the laser floating zone melting method,may easily transform into 2212 phase at layer or filament in shape which is favourable to improve the links among superconducting grains and critical current density.
关键词:
Bi system superconductor
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null
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null
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null
MA Zongyi YAO Zhongkai Harbin Institute of Technology
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Harbin
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China
金属学报(英文版)
The SiC_w/Al composite prepared by squeeze casting has a combination of superior room temperature specific strength and modulus together with excellent thermal properties.The extrusion can make an improvement on the strength and ductility of the composite from 582 MPa as squeeze casted up to 639 MPa,and on the transformation from isotropic to the anisotropic structure.This seems to be explained by the orientation of whiskers and the densification of dislocations in matrix.TEM observation indicates that the stacking fault is the usual planar defect on the SiC_w surface. composite;;SiC whisker;;Al alloy;;microstructure
关键词:
composite
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null
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null
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Corrosion
This paper introduces the design of a localized corrosion rate monitoring instrument that can monitor and evaluate the maximum and stable localized corrosion rate of a nonpassivable metal in a corrosive environment by measuring the current density in a corrosion sensor with an occluded anode.
关键词:
instrument;localized corrosion rate;monitor
Applied Physics Letters
Uniform Ge-nanocrystals (Ge-ncs) embedded in amorphous SiO(2) film were formed by using (74)Ge(+) ion implantation and neutron transmutation doping (NTD) method. Both experimental and theoretical results indicate that the existence of As dopants transmuted from (74)Ge by NTD tunes the already stabilized (crystallized) system back to a metastable state and then activates the mass transfer processes during the transition form this metastable state back to the stable (crystallized) state, and hence the nanocrystal size uniformity and higher volume density of Ge-ncs. This method has the potential to open a route in the three-dimensional nanofabrication. (C) 2011 American Institute of Physics. [doi:10.1063/1.3553770]
关键词:
transmutation-doped gaas;electrical-properties;misfit dislocations;lasers go;silicon;films
王君
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邹家桂
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陈政标
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高建武
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刘彦坤
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张杰元
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宋莎
绝缘材料
为解决苯乙烯和甲基苯乙烯在VPI浸渍树脂应用于风力发电机中的不足,采用不饱和聚酯亚胺、引发剂和无挥发活性稀释剂研制出116HU聚酯亚胺无挥发浸渍树脂,并对其各项性能进行了研究。结果表明:116HU聚酯亚胺无挥发浸渍树脂的常规性能满足风力发电机的要求,其耐热等级可达H级。用该树脂浸渍的风电模拟线棒具有优异的介电性能、耐湿热交变和高低温循环冲击性能及耐盐雾性能等,能满足风力发电机在极端环境运行的要求。
关键词:
聚酯亚胺
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无挥发
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VPI
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风力发电机
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耐湿热
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耐盐雾