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High Temperature Deformation of Al_2O_3/Cu Composites

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Journal of Materials science & technology 2001年第3期17卷 325-328页

作者： Jianjun WU. Yun ZHANG, Yanfei JIANG and Meiyun XUE Department of Material science and Engineering, Hebei University of technology, tianjin 300130, China Tingquan LEI School of Materials science and Engineering, Harbin institute of technology, Uarbin 15000 Hebei Univ technol Dept Mat Sci & Engn Tianjin 300130 Peoples R China Harbin inst technol Sch Mat Sci & Engn Harbin 150006 Peoples R China

This work concerns with the high temperature deformation of internally oxidized Al2O3/Cu composites. The investigation revealed that dispersive alumina can obstruct dislocation sliding and define the subgrain size thereby improve significantly the strength of the materials at high temperature. The sliding of dislocations is a main deformation mechanism in the given temperature range. The sliding of grain boundary and diffusive creep play important roles at high temperature and low strain rate. The dispersoids can raise the recrystallization temperature to higher than 1223 K. Dynamic recovery is a main softening way under the experimental conditions. Higher deformation rate and lower deformation temperature imply a higher flow stress.

关键词： High Temperature Deformation of Al2O3/Cu Composites Cu Al

Reaction thermodynamics and kinetics on in situ Al_2O_3/Cu composites

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中国有色金属学会会刊：英文版 1999年第3期9卷 617-622页

作者： Li Guobin(李国彬) 1, Wu Jianjun(武建军) 1, Guo Quanmei(郭全梅) 2, Jiang Yanfei(姜延飞) 1, Shen Yutian(申玉田) 1, Lei Tingquan(雷廷权) 2 1. Department of Materials science and Engineering, Hebei University of technology, tianjin 300130, P.R.Chi Hebei Univ technol Dept Mat Sci & Engn Tianjin 300130 Peoples R China Harbin inst technol Sch Mat Harbin 150006 Peoples R China

The preferred internal oxidation of aluminum in Cu Al alloy was used to obtain in situ Al 2O 3/Cu composites. The reinforcement particles were mainly γ Al 2O 3, some θ Al 2O 3 and a little α Al 2O 3. Thermodynamics analyses show that the chemical reactions are 3Cu 2O+2Al=6Cu+Al 2O 3 or 3CuO+2Al=3Cu+Al 2O 3. A related equilibrium diagram was drawn. The experiments and investigation show that the formation rate of Al 2O 3 was controlled by the diffusion of oxygen in matrix.

关键词： Al 2O 3/Cu composites internal oxidation thermodynamics kineticsDocument code: A

Metal-organic framework loaded manganese oxides as efficient catalysts for low-temperature selective catalytic reduction of NO with NH3

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Frontiers of Chemical science and Engineering 2017年第4期11卷 594-602页

作者： Zhang, Minhua Huang, Baojuan Jiang, Haoxi Chen, Yifei tianjin Univ Key Lab Green Chem Technol Minist Educ R&D Ctr Petrochem Technol Tianjin 300072 Peoples R China Collaborat Innovat Ctr Chem sci & Engn Tianjin 300072 Peoples R China

A mild in-situ deposition method was used to fabricate Mn-based catalysts on a UiO-66 carder for the selective catalytic reduction of NO by NH3 （NH3-SCR）. The catalyst with 8.5 wt-% MnOx loading had the highest catalytic activity for NH3-SCR with a wide temperature window （100-290 C） for 90% NO conversion. Char- acterization of the prepared MnOx/UiO-66 catalysts showed that the catalysts had the crystal structure and porosity of the UiO-66 carrier and that the manganese particles were well-distributed on the surface of the catalyst. X-ray photoelectron spectroscopy analysis showed that there are strong interactions between the MnOx and the Zr oxide secondary building units of the UiO-66 which has a positive effect on the catalytic activity. The 8.5 wt-% MnOx catalyst maintained excellent activity during a 24-h stability test and exhibited good resistance to SO2 poisoning.

关键词： metal-organic framework selective catalyticreduction manganese oxides deNOx SO2 resistance

Effect of As Interstitial Diffusionon on the Properties of Undoped Semi-insulating LECGaAs

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Rare Metals 2001年第3期20卷 187-191页

作者： Ruixia Yang, Fuqiang Zhang, Nuofu Chen 1) Hebei University of technology, tianjin 300130, China 2) institute of Semiconductors, Chinese Academy of sciences, Beijing 100083, China Hebei Univ technol Tianjin 300130 Peoples R China Chinese Acad sci Inst Semicond Beijing 100083 Peoples R China

Annealing was carried out at 950 and 1120 degreesC under various As pressure for undoped (ND) semi-insulating (SI) LECGaAs. The effects of annealing on native defects and electrical properties were investigated. Experimental results indicate that, after an annealing at 950 degreesC for 14 h under low As pressure, the Hall mobility decreases and the resistivity increases dramatically for the samples. These changes in electrical properties are due to the generation of intrinsic acceptor defects, and the generation of the intrinsic acceptor defects originates from the outdiffusion of As interstitial at high temperature. The generation of the intrinsic defects and these changes in electrical properties can be suppressed by increasing the applied As pressure during annealing. The concentration of the main donor defect E12 (AsGaVGa) can be decreased by about one order of magnitude by an evacuated annealing at 1120 degreesC for 2-8 h followed by a fast cooling. The decrease in E12 concentration can also be suppressed by increasing the As pressure during annealing.

关键词： semi-insulating GaAs intrinsic acceptor defects As interstitial indiffusion As pressure annealing

Effect of Austenite Pre-deformation on Isothermal Martensite Transformation in an Fe-20.5Ni-4.8Mn Alloy

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Journal of Materials science & technology 1995年第1期11卷 61-66页

作者： Fuxing YIN Jianxin ZHANG and Nanju GU(Hebei institute of technology, tianjin, 300132, China)Tsukio Tadaki(institute of science and Industrial Research, Osaka University, Japan)Ken,ichi Shimizu(Kanazawa institute of technology, Ishigawa 921, Japan) HEBEI inst technol TIANJIN 300132PEOPLES R CHINA OSAKA UNIV INST SCI & IND RESOSAKAJAPAN KANAZAWA inst technol KANAZAWAISHIKAWA 921JAPAN

With electron microscopy the investigation on isothermal martensite transformation in an Fe20.5Ni-4.8Mn alloy has been carried out to clarify the effect of austenite state on the transformation, by applying pre-deformation to austenite before isothermal holding. Under the condition without pre-deformation, the isothermal martensite products are lath martensite with {111}fhabit planes. Dislocations in austenite seem to contribute to nucleation of martensite, and in this nascent Stage austenite substructure has no obvious effect on martensite growth. The consequent thickening of martensite laths is apparently influenced by local austenite states, resulting in the changes in orientation, morphology as well as substructure of martensite lath. The kinetics of isothermal martensite transformation is controlled by intedece dislocation determined nucleation of martensite in primary stage, but to a larger extent, by the austenite accommodation for the shape strain of martensite in the thickening Stage

关键词： Mn Ni Fe Effect of Austenite Pre-deformation on Isothermal Martensite Transformation in an Fe-20.5Ni-4.8Mn Alloy Figure

A new heterocyclic compound from Cyathula officinalis Kuan

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Chinese Chemical Letters 2010年第1期21卷 70-72页

作者： Liu, Jie Xu, Jing Zhao, Xiao Jun Gao, Wen Yuan Zhang, Shu Zhong Guo, Yuan Qiang Nankai Univ Coll Pharmaceut Sci Tianjin 300071 Peoples R China tianjin Normal Univ Coll Chem & Life Sci Tianjin 300387 Peoples R China tianjin Univ Sch Pharmaceut Sci & Technol Tianjin 300072 Peoples R China Nankai Univ State Key Lab Elementoorgan Chem Tianjin 300071 Peoples R China

A new heterocyclic compound,named 5,5 -diisobutoxy-2,2 -bifuran(1),and four known compounds(2-5) were isolated from the roots of Cyathula officinalis *** structures were elucidated by spectroscopic *** these compounds... 详细信息

关键词： Cyathula officinalis Kuan 5 5 -Diisobutoxy-2 2 -bifuran Heterocyclic compound

STRONG LAW OF LARGE NUMBERS AND SHANNON-MCMILLAN THEOREM FOR MARKOV CHAINS FIELD ON CAYLEY TREE

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Acta Mathematica scientia 2001年第4期21卷 495-502页

作者：杨卫国刘文 Jiangsu Univ sci & technol Fac Sci Zhenjiang 212013 Peoples R China Hebei Univ technol Tianjin 300130 Peoples R China

This paper studies the strong law of large numbers and the Shannom-McMillan theorem for Markov chains field on Cayley tree. The authors first prove the strong law of large number on the frequencies of states and orderd couples of states for Markov chains field on Cayley tree. Then they prove the Shannon-McMillan theorem with a.e. convergence for Markov chains field on Cayley tree. In the proof, a new technique in the study the strong limit theorem in probability theory is applied.

关键词： Cayley tree random field Markov chains field strong law of large numbers Shannon-McMillan theorem

The effect of doping and steam treatment on the catalytic activities of nano-scale H-ZSM-5 in the methanol to gasoline reaction

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Frontiers of Chemical science and Engineering 2017年第4期11卷 564-574页

作者： Song, Baodong Li, Yongqiang Sun, Zhenhai Cao, Gang Han, Xu tianjin Univ Sch Chem Engn & Technol Tianjin 300072 Peoples R China Nankai Univ Catalyst Co Ltd Tianjin 300072 Peoples R China tianjin Univ Sch Environm Sci & Engn Key Lab Indoor Air Environm Qual Control Tianjin 300072 Peoples R China

In the transformation of methanol to gasoline （MTG）, the selectivity to gasoline and the aromatic content in the produced gasoline are important factors. The catalytic activities of steam-treated and non-steam-treated nano-scale H-ZSM-5 （NHZ5） catalysts impregnated with Ag（I）, Zn（II） or P（V） have been investigated in a continuous flow fixed bed reactor. The NH3-TPD results showed that after impregnation, the Ag/NHZ5, Zn/NHZ5 and P/NHZ5 catalysts contained comparatively more strong, medium-strong and weak acid sites, respectively. Treatment with steam decreased the number of acid sites in all the catalysts, but the pore volumes in the catalysts were larger which improved carbon deposition resistance resulting in prolonged lifetimes. After 6 h of MTG reaction, the selectivity to gasoline for the steam-treated catalysts, Agrho/NHZ5, ZnH2o/NHZ5 and PH2o/NHZ5 were 70.5, 68.4 and 68.7 wt-%, respectively, whereas their respective aromatic contents in the produced gasoline were 61.9, 55.4 and 39.0 wt-%. Thus Pn2o/NHZ5 is the most promising catalyst for MTG applications which can meet the China IV gasoline standard that the amount of aromatics in gasoline should be less than 48 wt-%.

关键词： MTG nano-scale H-ZSM-5 steam treatment,gasoline selectivity to gasoline

Point defects in active layers of TFEL devices based on ZnS

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Chinese science Bulletin 1998年第6期43卷 518-522页

作者： Zhidong Lou A. N. Georgobiani Zheng Xu Chunxiang Xu Feng Teng Lei Yu Xurong Xu tianjin Univ Dept Appl Phys Tianjin 300072 Peoples R China PN Lebedev Phys inst Moscow 117924 Russia No Jiaotong Univ Dept Phys Beijing 100044 Peoples R China tianjin inst technol Inst Mat Phys Tianjin 300191 Peoples R China Chinese Acad sci Changchun Inst Phys Lab Excited State Proc Changchun 130021 Peoples R China

Point defects in the active layer of a layered optimization thin film electroluminescent device of ZnS: Er 3+ were studied. The results indicate that besides Er 3+ substituting for Zn 2+ as luminescent centers, the dominant point defects are sulfur vacancies, zinc vacancies, shallow donors and deep acceptors. Their influence on electroluminescence is

关键词： spectra of photoluminescence point defects thin film electroluminescence.