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The existence and stability of traveling waves with transition layers for the S-K-T competition model with cross-diffusion

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Science China Mathematics 2010年第5期53卷 124-147页

作者： Wu YaPing Zhao Ye Capital Normal Univ Dept Math Beijing 100048 Peoples R China beijing inst Petrochem technol Dept Math & Phys Beijing 102617 Peoples R China

This paper is concerned with the existence and stability of traveling waves with transition layers for a quasi-linear competition system with cross diffusion,which was first proposed by Shegesada,Kawasaki and *** one of the random diffusion rates is small and the cross-diffusion rate is not small,by the geometric singular perturbation method,the existence of traveling waves with transition layers is ***,by the detailed spectral analysis and topological index method,the traveling waves with transition layers are proved to be locally exponentially stable with shift.

关键词： traveling waves existence stability cross-diffusion spectral analysis unstable bundle

Mineralogical alteration of thermally treated siderite in air: Mossbauer spectroscopy results

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Chinese Science Bulletin 1999年第18期44卷 1712-1717页

作者： Pan, YX Zhu, RX Ping, JY Chinese Acad Sci Inst Geophys Beijing 100101 Peoples R China beijing Univ Sci & technol Dept Phys Mat Beijing 100083 Peoples R China

Mineralogical alternation of thermally treated siderite in air atmosphere has been systematically analyzed by Mossbauer effects. It was preliminarily estimated from the area of sub-spectra that 4% , 39% and 62% of magnetite were formed at 410℃, 490℃ and 510℃ respectively. After being incrementally heated at 530℃ the spectra consist of two sextets of Fe3O4. Sextet of γ-Fe2O3 with hyperfine field of 50T was observed at 550℃. Spectra at 580℃

关键词： siderite mineralogical phase transition thermally treated in air.

FEATURES　OF　ANNEALING　MICROSTRUCTURE　AND　TEXTURE　IN　Ti－25Al－10Nb－3V－1Mo　SHEET

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中国有色金属学会会刊：英文版 1996年第2期6卷 67-71页

作者： Mao, WM Yu, YN Yang, H Song, B Zou, DX Wang, B UNIV SCI & technol beijing DEPT MAT SCI & ENGNBEIJING 100083PEOPLES R CHINA MINIST MET IND DEPT SUPERALLOYCENT IRON & STEEL RES INSTBEIJING 100081PEOPLES R CHINA

ＦＥＡＴＵＲＥＳＯＦＡＮＮＥＡＬＩＮＧＭＩＣＲＯＳＴＲＵＣＴＵＲＥＡＮＤＴＥＸＴＵＲＥＩＮＴｉ－２５Ａｌ－１０Ｎｂ－３Ｖ－１ＭｏＳＨＥＥＴＭａｏＷｅｉｍｉｎ；ＹｕＹｏｎｇｎｉｎｇ；ＹａｎｇＨｏｎｇ；ＳｏｎｇＢｏ（Ｄｅ... 详细信息

ＦＥＡＴＵＲＥＳＯＦＡＮＮＥＡＬＩＮＧＭＩＣＲＯＳＴＲＵＣＴＵＲＥＡＮＤＴＥＸＴＵＲＥＩＮＴｉ－２５Ａｌ－１０Ｎｂ－３Ｖ－１ＭｏＳＨＥＥＴＭａｏＷｅｉｍｉｎ；ＹｕＹｏｎｇｎｉｎｇ；ＹａｎｇＨｏｎｇ；ＳｏｎｇＢｏ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｅｒｉａ...

关键词： Ti-25-A1-10Nb-3V-1Mo texture rolling deformation annealing

Microstructure and Tensile Properties of Spray-deposited IC6 Alloy

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Journal of Materials Science & technology 1998年第2期14卷 143-146页

作者： Mi, Guofa Li, Zhou Tian, Shifan Zhao, Xianguo Luo, Zhiping Zeng, Songyan Li, Qingchun inst Aeronaut Mat Beijing 100095 Peoples R China Harbin inst technol Sch Mat Sci & Engn Harbin 150001 Peoples R China

The microstructure and mechanical properties of a Ni//3 Al based Ni-Al-Mo superalloy-IC6 which possesses low impurity content and high density by spray deposition technique have been studied. The results indicate that the IC6 alloy has good tensile strength and elongation both at room and intermediate temperatures. (Edited author abstract) 6 Refs.

关键词： Nickel alloys

Numerical Simulation of Dieless Drawing Process with Non-steady Processing Parameters

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稀有金属材料与工程 2011年第S3期40卷 179-184页

作者： He Yong, Liu Xuefeng, Wang Zhen, Xie Jianxin University of Science and technology beijing, beijing 100083, China Univ Sci & technol beijing Key Lab Adv Proc Technol Mat Minist Educ Beijing 100083 Peoples R China

Since processing parameters have always been assumed to be stable in the current finite element numerical simulation of dieless drawing process, the simulation results for the product dimension tend to stabilize gradually. In fact, the dimension fluctuation exists in the forming process all the while. A mathematical model of Gauss distribution for processing parameters was employed and a finite element numerical model of dieless drawing process with non-steady processing parameters was established. Dieless drawing processing of Ni-Ti alloy wire was conducted for verifying the proposed model. The results indicated that the non-steady processing parameters model had higher simulation accuracy of the wire diameter than that given by the steady parameters model. Furthermore, the model could also be used to analyze the fluctuation characteristics in the whole dieless drawing process.

关键词： dieless drawing non-steady processing parameter thermal-mechanical coupling finite element numerical simulation Gauss distribution

MECHANICAL PROPERTIES AND MICROSTRUCTURES OF Ti(C,N) BASED CERMETS

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中国有色金属学会会刊：英文版 1996年第4期6卷 117-121页

作者： Liu, N Hu, ZH Cui, K Liu, CL ANHUI inst technol DEPT MAT SCI & ENGNHEFEI 230069PEOPLES R CHINA HUAZHONG UNIV SCI & technol WUHAN 430074PEOPLES R CHINA beijing GEN RES inst IRON & STEEL BEIJING 100081PEOPLES R CHINA

ＭＥＣＨＡＮＩＣＡＬＰＲＯＰＥＲＴＩＥＳＡＮＤＭＩＣＲＯＳＴＲＵＣＴＵＲＥＳＯＦＴｉ（Ｃ，Ｎ）ＢＡＳＥＤＣＥＲＭＥＴＳ￥ＬｉｕＮｉｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｅｒｉａｌｓＳｃｉｅｎｃｅａｎｄＥｎｇｉｎｅｅｒｉ... 详细信息

ＭＥＣＨＡＮＩＣＡＬＰＲＯＰＥＲＴＩＥＳＡＮＤＭＩＣＲＯＳＴＲＵＣＴＵＲＥＳＯＦＴｉ（Ｃ，Ｎ）ＢＡＳＥＤＣＥＲＭＥＴＳ￥ＬｉｕＮｉｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｅｒｉａｌｓＳｃｉｅｎｃｅａｎｄＥｎｇｉｎｅｅｒｉｎｇ，ＡｎｈｕｉＩｎｓｔｉｌｕｔｅ...

关键词： Ti(C,N) based cermets mechanical properties microstructure

CABOSFV algorithm for high dimensional sparse data clustering

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Journal of University of Science and technology beijing 2004年第3期11卷 283-288页

作者： Sen Wu Xuedong Gao Management School, University of Science and technology beijing, beijing 100083, China Mgmt. Sch. Univ. of Sci. and Technol. Beijing Beijing 100083 China

An algorithm, Clustering Algorithm Based On Sparse Feature Vector (CABOSFV),was proposed for the high dimensional clustering of binary sparse data. This algorithm compressesthe data effectively by using a tool 'Sparse Feature Vector', thus reduces the data scaleenormously, and can get the clustering result with only one data scan. Both theoretical analysis andempirical tests showed that CABOSFV is of low computational complexity. The algorithm findsclusters in high dimensional large datasets efficiently and handles noise effectively.

关键词： clustering data mining sparse high dimensionality

Applicability of mass action law to sulphur distribution between slag melts and liquid iron

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Journal of University of Science and technology beijing 2002年第2期9卷 90-98页

作者： Jian Zhang Metallurgy School, University of Science and technology beijing, beijing 100083, China Metall. Sch. Univ. of Sci. and Technol. Beijing Beijing 100083 China

According to the mass action law and the coexistence theory of slagstructure, the calculating models of mass action concentration for CaO-MgO-FeO-Fe_2O_3-SiO_2,CaO-MgO-MnO-FeO-Fe_2O_3-P_2O_5-SiO_2 and CaO-MgO-MnO-FeO-Fe_2O_3-Al_2O_3-P_2O_5-SiO_2 slag melts areformulated and sulphur distribution between the slag melts and liquid iron is treated. It is foundthat CaO, MnO and FeO promote desulphurization, while MgO is detrimental to desulphurization. Inaddition, the sulphur distribution coefficients between the slag melts and liquid iron andpresented.

关键词： mass action law coexistence theory of slag structure activity massaction concentration

Application of the annexation principle to the thermodynamic property study of ternary metallic melts In-Bi-Cu and In-Sb-Cu

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Journal of University of Science and technology beijing 2002年第3期9卷 170-176页

作者： Man ZhangMetallurgy School, University of Science and technology beijing, beijing 100083, China (Received 2001-10-27) Metall. Sch. Univ. of Sci. and Technol. Beijing Beijing 100083 China

Based on the phase diagrams, measured activities and the annexationprinciple, calculating models of mass action concentrations for In-Bi-Cu and In-Sb-Cu melts havebeen formulated. Calculated results not only agree well with practical values, but also obey themass action law, showing that the deduced model can reflect the structural reality of given meltasand that the annexation principles is applicable to these tow ternary metallic melts. So long asthere is one from three binary systems constituting the ternary melts, in which the activities ofone component exhibit positive deviation relative to Raoultian behavior, heterogeous meltsinevitably would form, so heterogeneous calculating model should be used to calculate their massaction concentrations. On the contrary, if all the binary melts are homogeneous and their activitiesexhibit negative deviation with respect to the Raoult's law, then the ternary melts formed fromthem will certainly be homogeneous, hence single phase model should be applied.

关键词： activity mass action concentration coexistence theory annexationprinciple