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Effect of Heat Treatment on High Temperature Stress Rupture Strength of Brazing Seam for Nickel-base Superalloy

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Journal of university of science and Technology beijing 2001年第2期8卷 123-125页

作者： Junying Zhang, Zhongtai Zhang, Jisheng Sun, Xiaofang Liu, Wei Tian (State key laboratory of New Ceramics and Fine Processing, department of materials science and engineering, tsinghua university, beijing 100084, china) (beijing Institute of Aeronautical SKLNCFP Dept. of Materials Sci. and Eng. Tsinghua University Beijing 100084 China

In order to enhance the high-temperature stress rupture strength of brazing seam by heat treatment, it was diffusion treated, then solution heat treated, and finally aging treated. The microstructure of brazing seam especially morphology of gamma ' phase and boride was observed and the strength of brazing seam was measured in this process. The results show that heat treatment can enhance high-temperature stress rupture strength by improving the microstructure of brazing seam. The strength of brazing seam after solution heat treatment decreases in comparison with that only after diffusion treatment while aging treatment after solution heat treatment increases the strength of brazing seam.

关键词： wide-gap brazing high temperature stress rupture strength microstructure nickel-base superalloy

A scheme to implement the Deutsch-Josza algorithm on a superconducting charge-qubit quantum computer

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Progress in Natural science:materials International 2006年第6期16卷 594-599页

作者： HUO Wenyi and LONG Guilu (key laboratory for Quantum Information and Measurements, and department of Physics, tsinghua university, beijing 100084, china key laboratory for Atomic and Molecular Nanosciences, tsinghua university, beijing 100084, china) key laboratory for Quantum Information and Measurements and Department of Physics Tsinghua University Beijing 100084 China key laboratory for Atomic and Molecular Nanosciences Tsinghua University Beijing 100084 China

We have studied the implementation of the Deutsch-Josza quantum algorithm in a superconducting charge-qubit quantum computer. Different from previous studies, we have used the inductance coupled system of You et al. The detailed pulse sequences have been designed for the four possible functions in a 2-qubit system. The result is generalized to an arbitrary n-qubit system. This scheme will be useful for practical implementation of the algorithm.

关键词： superconducting quantum computer Deutsch-Josza algorithm.

Strain rate sensitivity and activation volume of electrodeposited nanocrystalline Ni and Ni-Co alloys

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Rare Metals 2007年第S1期26卷 134-138页

作者： LIAN Jianshe,GU Changdong,LI Guangyu,and JIANG Qing key laboratory of Automobile materials,ministry of education,department of materials science and engineering,Jilin university,Changchun 130025,china Jilin Univ Dept Mat Sci & Engn Minist Educ Key Lab Automobile Mat Changchun 130025 Peoples R China

Tensile deformation behaviors of the electrodeposited 40 nm grain sized Ni,25 nm Ni-1.7 wt.%Co,and 13 nm Ni-8.6 wt.%Co alloys at various strain rates and room temperature were reviewed with emphasis on strain rate sensitivity and activation volume,*** is found that the strain rate sensitivity and activation volume were strongly grain size *** analytic model based on the bow out of a single dislocation well predicted the relationship between the strain rate sensitivity and the activation volumes for these nanocrystaline metals.

关键词： nanocrystalline mechanical properties strain rate sensitivity activation volume Ni-Co alloy Ni

Micro-alloying of yttrium in Zr-based bulk metallic glasses

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Progress in Natural science:materials International 2011年第1期21卷 46-52页

作者： Wei-jie PENG,Yong ZHANG State key laboratory for advanced Metals and materials, university of science and Technology beijing,beijing 100083,china university of science and Technology beijing

The effect of yttrium addition on the glass-forming ability(GFA) and mechanical properties of the Zr-based (Zr0.525Al0.1Ti0.05Cu0.179Ni0.146)100-xYxand(Zr0.55Al0.15Ni0.1Cu0.2)100-xYx(x=0,0.2,0.4 0.6,1,2) alloys was ***-alloying of 0.6%yttrium enhances the room temperature ductility as well as the GFA of the Zr-based *** mechanism of enhancing the GFA and room temperature ductility was *** is indicated that proper yttrium addition stabilizes the undercooled liquid by means of forming lots of ordered clusters,thus improving the GFA and the room temperature ductility.

关键词： micro-alloying glass-forming ability Zr-based alloys yttrium

EffectofEr^(3+) and Nd^(3+)doping on the luminescent properties of BaMgAl_(10)O_(17):Euphosphor

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Rare Metals 2003年第1期22卷 60-63页

作者： ZHANGLin ZHANGJunying ZHANGZhongtai CenterformaterialsPhysiceandChentistry SchoolofSciencesBeiHangUniversityBeijing100083China PersonnelDivision UniversityofSciehceandTechnologyBeijingBeijing100083China StatekeylaboratoryofNewCeram

BaMgAl_(10)O_(17):Eu blue phosphors were synthesized and the effect of dopingE^(3+) and Nd^(3+) ions in the phosphor on the luminescent properties was investigated. When thecontent of Er^(3+) and Nd^(3+) ions is small, the phosphor remains single phase and the luminescentintensity of Eu^(2+) increases effectively. When Er^(3+) is doped, the shape of the excitationspectrum of the phosphor in the UV (ultraviolet) region remains unchanged. As Nd^(3+) is doped inthe phosphor, the location and intensity of the two excitation peaks, and the emission intensityratio excited by corresponding UV change dramatically owing to the alternation of crystal fieldsplitting and level barycenter of 4f^6 5d configuration of Eu^(2+) ion.

关键词： phosphor spectrum luminescent property

Preparation of micro-patterned surfaces of Si-N-O films and their influence on adhesion behavior of endothelial cells

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science china(Technological sciences) 2010年第1期53卷 257-263页

作者： ZHENG Nan,YANG Ping,WANG QiYi,YANG ZhongHai & HUANG Nan key laboratory of advanced Technology for materials of education ministry,key laboratory of Artificial Organ Surface engineering of Sichuan,School of materials science and engineering,Southwest Jiaotong university,Chengdu 610031,china key laboratory of advanced Technology for materials of education ministry Key Laboratory of Artificial Organ Surface Engineering of Sichuan School of Materials Science and Engineering Southwest Jiaotong University

Microgrooves were prepared on Si(100) surface by photolithography and wet ***,Si-N-O films were deposited on the microgrooves by unbalanced magnetron sputtering(UBMS) and micro-patterned surfaces of Si-N-O films were *** size of the micropatterns was measured by surface *** chemical composition of Si-N-O films were characterized by X-ray photoelectron spectrometry(XPS) and the wettability of the micropatterned surfaces was evaluated by contact angle *** behavior of endothelial cells adhered on the micro-patterned surfaces,including cells adhesion,proliferation and orientation,was evaluated by cell culture test and Alamar blue *** results showed that the amount and activity of endothelial cells on micro-patterned samples were higher than those on flat *** one day's incubation,the cells were well guided along the *** days later,most of the cells grew across the grooves and contacted each *** activity was also much higher than that on flat *** was suggested that the adhesion and proliferation of endothelial cells could be effectively enhanced by micropattern method.

关键词： micropatterns Si-N-O film endothelial cell unbalanced magnetron sputtering

Cloning and characterization of cotton heteromeric acetyl-CoA carboxylase genes

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Progress in Natural science:materials International 2007年第12期17卷 1412-1418页

作者： Qiao Zhixin and Liu Jinyuan(laboratory of Molecular Biology and Protein science laboratory of the ministry of education, department of Biological sciences and Biotechnology, tsinghua university, beijing 100084, china) laboratory of Molecular Biology and Protein science laboratory of the ministry of education Department of Biological Sciences and Biotechnology Tsinghua University Beijing 100084 China

Heteromeric acetyl-coenzyme A (CoA) carboxylase (ACCase) catalyzes the formation of malonyl-CoA from acetyl-CoA. It plays an essential role in fatty acid synthesis in prokaryotes and most of plants. The heteromeric ACCase is composed of four subunits: biotin carboxylase (BC), biotin carboxyl carrier protein (BCCP), and α- and β-subunits of carboxyltransferase (α- and β-CT). In this study, we cloned five novel genes encoding the subunits of heteromeric ACCase (one BC, BCCP and β-CT, and two α-CTs) from cotton (Gossypium hirsutum cv. zhongmian 35) by RACE-PCR. The deduced amino acid sequence of these cDNAs shares high similarity with other reported heteromeric ACCase subunits. The phylogenetic analysis indicated that the different subunits of heteromeric ACCase were grouped in a similar pattern. Southern blot analysis revealed the milti-copy patterns of these heteromeric ACCase genes in cotton genome. Semi-quantitative RT-PCR demonstrated that heteromeric ACCase genes were constitutively expressed in all of the cotton tissues, but the transcripts accumulated at a relatively low level in roots. To our knowledge, this is the first report about characterization of the heteromeric ACCase genes in cotton.

关键词： heteromeric ACCase cotton gene cloning fatty acid synthesis.

Dynamic recrystallization during hot torsion of Al-4Mg alloy

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Journal of university of science and Technology beijing 2003年第2期10卷 45-48页

作者： Junpin Lin, Yanli Wang, Zhi Lin, and Guoliang ChenState key laboratory of advanced Metal materials, university of science and Technology beijing, beijing 100083, china Lab. of Adv. Metal Mat. Univ. of Sci. and Technol. Beijing Beijing 100083 China

Binary Al-4Mg alloy have been deformed by hot torsion at 300-500 deg C andstrain rates of 0.006-1.587 s^(-1) to a true strain of 5.5. The specimens were annealed in vacuumfor 1.5 h at 500 deg C and then water quenched. The study indicates that the dynamicrecrystallization occurs during hot torsion of Al-4Mg alloy in a certain range of Z parameter(Zener-Hollmon Parameter), i.e. 19.3 4.8. Increasing the strain rate at higher deformationtemperature or reducing the strain rate at lower deformation temperature accelerates the occurrenceof dynamic recrystallization in the alloy.

关键词： Al-4Mg alloy dynamic recrystallization hot torsion

Crystal structures and electronic properties of BaC_2 isomers by theoretical study based on DFT

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science china Chemistry 2008年第6期51卷 545-550页

作者： FENG Jing1,XIAO Bing2 & CHEN JingChao1 1 key laboratory of advanced materials of Precious-Nonferrous Metals,education ministry of china,and key Lab of advanced materials of Yunnan Province,Kunming university of science and Technology,Kunming 650093,china 2 School of materials science and engineering,Xi’an Jiaotong university,Xi’an 710049,china key laboratory of advanced materials of Precious-Nonferrous Metals Education Ministry of China and Key Lab of Advanced Materials of Yunnan Province Kunming University of Science and Technology Kunming 650093 China School of materials science and engineering Xi'an Jiaotong University Xi'an 710049 China

Band structures and electronic properties of two BaC2 isomers were calculated by using density func-tional theory(DFT) *** ionic bond features are all typical between cation(Ba) and anion clusters(C2) in both structures of the ***,a much stronger covalent bond exists in anion clusters which can be seen by inspecting the electron distribution contour that has a dull bell like shape between two carbon *** shortest distance between Ba2+ and C22? and the bond length in anion clusters are different in these isomers of BaC2,which are 0.2945 nm and 0.1185 nm for the structure with the I4/mmm space group and 0.2744 and 0.1136 nm with the C2/c type,*** structures were clarified by combining the DOS to indicate the ionic bonding features more *** analysis provided further evidence on these *** calculation results reveal that the transition temperature of these two polymorphs of BaC2 locates near 132 K,which is consistent with the recent experimental results.

关键词： functional materials metal diaries phase transition electron density first principle calculation orbital bonding state