JIANG Tao SU Yuanfu Chemical Engineering Research Center
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East China University of Chemical Technology
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Shanghai
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China
金属学报(英文版)
Studies have been made on the extraction of Zn and Cd by TBP(tri-n-butyl phosphate) from diluent hydrochloric acid solutions of soldium chloride.The experiments show that the species extracted from diluent HCI solutions of NaCl appear to be predominantly ZnCl_2· 2TBP and CdCl_2·2TBP.For Cd,at lower acidities,anionic complexes of the type H_2CdCl_3 are also extracted.As the acidity is increased,H_2CdCl_4 appear to be predominant complexes in organic phase.For Zn,the acidocomplexes of the type HZnCl_3 appear in organ- ic phase after the acidity of solutions reaching a certain value([HCl]>0.1 mol/L). Furthermore,the ultraviolet absorption spectra of both aqueous and organic phases have been studied,and the infrared spectra of the organic phases have been exomined.The extraction mechanism and temperature effect are also discussed.
关键词:
extraction
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null
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null
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null
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null
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null
Y.Chen X.Chen A.M.Guo D.X.Luo
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B.F.Xu
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Z.X.Yuan
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P.H.Li
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S.K.Pu
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S.B.Zhou
金属学报(英文版)
The different chemical composition of silicon and manganese as well as different re-tained austenite fraction ranged from 4to 101163326174f the high strength and high elon-gation steels were studied in the paper.The dislocations and carbon concentration in retained austenite were observed by a transmission electron microscope and an electric probe analyzer,respectively.The experimental results showed that silicon and manganese are two fundamental alloying elements to stabilize austenite effectively but retaining austenite in different mechanis-↑ms.Meanwhile,the cooling processing played an important role in controlling the fraction of retained austenite of the hot-rolled high strength and high plasticity steels.
关键词:
high strength
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null
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null
Andrej Atrens
材料科学技术（英文）
Corrosion research by Atrens and co-workers has made significant contributions to the understanding of the service performance of engineering materials. This includes: (1) elucidated corrosion mechanisms of Mg alloys, stainless steels and Cu alloys, (2) developed an improved understanding of passivity in stainless steels and binary alloys such as Fe-Cr, Ni-Cr, Co-Cr, Fe-Ti, and Fe-Si, (3) developed an improved understanding of the melt spinning of Cu alloys, and (4) elucidated mechanisms of environment assisted fracture (EAF) of steels and Zr alloys. This paper summarises contributions in the following: (1) intergranular stress corrosion cracking of pipeline steels, (2) atmospheric corrosion and patination of Cu, (3) corrosion of Mg alloys, and (4) transgranular stress corrosion cracking of rock bolts.
关键词:
Stress corrosion cracking
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null
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null
刘文鹏
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张庆礼
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杨华军
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周鹏宇
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孙敦陆
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高进云
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谷长江
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罗建乔
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王迪
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殷绍唐
量子电子学报
doi:10.3969/j.issn.1007-5461.2011.02.018
采用固相反应法制备了Bi3+、Eu3+、Tb3+掺杂的Lu3TaO7.测量了样品的X射线衍射谱、激发和发射光谱及荧光衰减曲线.三种离子掺杂的Lu3TaO7均呈现出强的荧光发射,其中Bi3+具有峰位在431 nm处的一强发射宽带,衰减寿命为16.8μs,Eu3+、Tb3+则表现出稀土离子的特征锐发射峰,衰减寿命分别为1.26 ms和1.20 ms.因此,它们均是具有潜在应用前景的重闪烁体材料.
关键词:
材料
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闪烁体
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Lu3TaO7
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发光
Materials Science & Engineering C-Biomimetic Materials Sensors and Systems
Bamboo, one of the strongest natural structural composite materials, has many distinguishing features. It has been found that its reinforcement unit, hollow, multilayered and spirally-wound bast fiber, plays an extremely important role in its mechanical behavior. In the present work, on the basis of the study on bamboo bast fiber and wood tracheid, a biomimetic model of the reinforcing element, composed of two layers of helically wound fiber, was suggested. To detect the structural characteristics of such a microstructure, four types of macro fiber specimens made of engineering composites were employed: axially aligned solid and hollow cylinders, and single- and double-helical hollow cylinders. These specimens were subjected to several possible loadings, and the experimental results reveal that only the double-helical structural unit possesses the optimum comprehensive mechanical properties. An interlaminar transition zone model imitating bamboo bast fiber was proposed and was verified by engineering composite materials. In our work, the transition zone can increase the interlaminar shear strength of the composite materials by about 15%. These biomimetic structural models can be applied in the design and manufacture of engineering composite materials.
关键词:
bamboo;bast fiber;biomimetics;engineering composites
U. Brill
金属学报(英文版)
The use of high-temperature materials is especially important in power station construction, heating systems engineering, furnace industry, chemical and petrochemical industry, waste incineration plants, coal gasification plants and for flying gas turbines in civil and military aircrafts and helicopters. Particularly in recent years, the development of new processes and the drive to improve the economics of existing processes have increased the requirements significantly so that it is necessary to change from well-proven materials to new alloys. Hitherto, heat resistant ferritic steels sufficed in conventional power station constructions for temperatures up to 550℃ newly developed ferritic/martensitic steels provide sufficient strength up to about 600-620℃. In new processes, e.g. fluidized-bed combustion of coal, process temperatures up to 900℃ occur. However, this is not the upper limit, since in combustion engines, e.g. gas turbines. Material temperatures up to 1100℃ are reached locally. Similar development trends can also be identified in the petrochemical industry and in the heat treatment and furnace engineering. The advance to ever higher material temperatures now not only has the consequence of having to use materials with enhanced high-strength properties, considerable attention now also has to be given to their chemical stability in corrosive media. Therefore not only examples of the use of high-temperature alloys for practical applications will be given but also be contributed to some general rules for material selection with regard to their high-temperature strength and corrosion resistance.
关键词:
nickel-based alloy
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null
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null
Science
Strengthening materials traditionally involves the controlled creation of internal defects and boundaries so as to obstruct dislocation motion. Such strategies invariably compromise ductility, the ability of the material to deform, stretch, or change shape permanently without breaking. Here, we outline an approach to optimize strength and ductility by identifying three essential structural characteristics for boundaries: coherency with surrounding matrix, thermal and mechanical stability, and smallest feature size finer than 100 nanometers. We assess current understanding of strengthening and propose a methodology for engineering coherent, nanoscale internal boundaries, specifically those involving nanoscale twin boundaries. Additionally, we discuss perspectives on strengthening and preserving ductility, along with potential applications for improving failure tolerance, electrical conductivity, and resistance to electromigration.
关键词:
strain-rate sensitivity;stacking-fault energy;nano-scale twins;cu-al;alloys;nanocrystalline metals;mechanical-properties;activation;volume;copper;deformation;behavior
