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Coarsening behavior of γ' and γ'' phases in GH4169 superalloy by electric field treatment

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International Journal of Minerals,Metallurgy and Materials 2013年第9期20卷 861-866页

作者： lei Wang Yao Wang Yang liu Xiu song Xu-dong lü Bei-jiang Zhang Key laboratory for Anisotropy and Texture of Materials Northeastern University Department of High-temperature Materials Central Iron and Steel Research Institute

The coarsening behaviors of γ′ and γ″ phases in GH4169 alloy aged at 1023 and 1073 K with electric field treatment （EFT） were investigated by transmission electron microscopy （TEM） and positron annihilation lifetime spectroscopy （PAlS）. It is demonstrated that precipitation coarsening occurs, and the growth activation energies of γ′ and γ″phases can be decreased to 115.6 and 198.1 ***1-1, respectively, by applying the electric field. The formation of a large number of vacancies in the matrix is induced by EFT. Due to the occurrence of vacancy migration, the diffusion coefficients of A1 and Nb atoms are increased to be 1.6-5.0 times larger than those without EFT at 1023 or 1073 K. Furthermore, the formation of vacancy clusters is promoted by EFT, and the increase in strain energy for the coarsening of γ′ and γ″ phases can be counterbalanced by the formation of vacancy clusters.

关键词： superalloys nickel alloys precipitation electric fields aging vacancies

Isothermal reduction kinetics of Panzhihua ilmenite concentrate under 30vol% CO–70vol% N2 atmosphere

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International Journal of Minerals,Metallurgy and Materials 2017年第3期24卷 240-248页

作者： Ying-yi Zhang Wei lü Xue-wei lü Sheng-ping li Chen-guang Bai Bing song Ke-xi Han College of Materials Science and Engineering Chongqing University Chongqing 400044 China Panzhihua Iron and Steel Research Institute Panzhihua 617000 China

The reduction of ilmenite concentrate in 30vol% CO–70vol% N_2 atmosphere was characterized by thermogravimetric and differential thermogravimetric(TG–DTG) analysis methods at temperatures from 1073 to 1223 *** isothermal reduction results show that the reduction process comprised two stages;the corresponding apparent activation energy was obtained by the iso-conversional and model-fitting *** the first stage,the effect of temperature on the conversion degree was not obvious,the phase boundary chemical reaction was the controlling step,with an apparent activation energy of 15.55–40.71 k J·mol^(–1).For the second stage,when the temperatures was greater than 1123 K,the reaction rate and the conversion degree increased sharply with increasing temperature,and random nucleation and subsequent growth were the controlling steps,with an apparent activation energy ranging from 182.33 to 195.95 k J·mol^(–1).For the whole reduction process,the average activation energy and pre-exponential factor were 98.94^(–1)18.33 k J·mol^(–1) and 1.820^(–1).816 min^(–1),respectively.

关键词： ilmenite isothermal reduction kinetics carbon monoxide

Structures and Stabilities of Ni_n(n=31―35) Clusters

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Chemical Research in Chinese Universities 2012年第2期28卷 291-294页

作者： song Wei lÜ Wen-cai Zang Qing-jun lI Qiu-xia State Key laboratory of Theoretical and Computational Chemistry Institute of Theoretical ChemistryJilin UniversityChangchun 130021P.R.China laboratory of Fiber Materials and Modern Textile the Growing Base for State Key LaboratoryCollege of PhysicsQingdao UniversityQingdao 266071P.R.China

The lowest-energy structures and properties of neutral nickel clusters Nin（n=31―35） were studied by a combination method of genetic algorithm（GA） searching with a tight-binding potential and the density functional theory（DFT） *** candidates obtained from our GA search were further optimized with first-principles *** typical isomers of lower-energy neutral Nin（n=31―35） clusters were shown,as well as their binding energies per atom（Eb）,second differences in energy and magnetic *** medium-sized nickel clusters in a size range from 31 atoms to 35 atoms were found to favor the distorted double-icosahedron-like *** fragments composed of the central atoms appear as some small stable clusters.

关键词： Nickel cluster Double-icosahedron Magnetic property

Geometrical Scale-Sensitive Fatigue Properties of Ti-6.5Al-3.5Mo-1.5Zr-0.3Si Alloys With α/β lamellar Microstructures

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Journal of Materials Science & Technology 2014年第12期30卷 1284-1288页

作者： B.Zhang Z.M.song l.M.lei l.Kang G.P.Zhang Key laboratory for Anisotropy and Texture of Materials Ministry of Education Northeastern University Shenyang National laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences AVIC Commercial Aircraft Engine Co. Ltd.

Fatigue properties of the Ti-6.5Al-3.5Mo-1.5Zr-0.3Si alloy sheets containing different numbers of α/β Widmansttten colonies in the thickness direction of the sheets were investigated by tensionetension fatigue testing. It is found that fatigue properties of the Ti alloy either in low- or high-stress amplitude regimes become more sensitive to the sheet thickness of the Ti alloy as the sheet thickness is comparable to the length scale of the Widmansttten colonies. The basic mechanism of such length scale-sensitive fatigue properties in the Ti alloy was elucidated.

关键词： Fatigue Ti alloy Microstructure Size effect

Multiplicity one, local and global conjugacy

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Science China Mathematics 2020年第6期63卷 1029-1038页

作者： song Wang Institute of Mathematics Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China

The issue of local and global conjugacy is closely related to the multiplicity one property in representation theory and the langlands program. In this article we give first families of connected instances for SO2N where the multiplicity one fails in both aspects of representation theory and automorphic forms with certain assumptions on the langlands functoriality.

关键词： multiplicity one l-adic Galois representation local conjugacy global conjugacy

Hydrothermal Synthesis, Crystal Structure and Thermal Analyses of Pyrazine-2,3-dicarboxylic Acid Bridged Co(II) Coordination Polymer of _∞~2[Co(phen)(μ-l)_(3/3)]·H_2O (H_2l = Pyrazine-2,3-dicarboxylic Acid)

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Chinese Journal of Structural Chemistry 2005年第4期24卷 478-482页

作者： ZHangBi-song NormalCollege JinhuaUniversityJinhua321017China

A novel pyrazine-2,3-dicarboxylic acid bridged Co(II) phen complex 2 ∞ [Co- ... 详细信息

A novel pyrazine-2,3-dicarboxylic acid bridged Co(II) phen complex 2 ∞ [Co- (phen)(μ-l)3/3]?H2O (H2l = pyrazine-2,3-dicarboxylic acid) has been hydrothermally synthesized, and X-ray single-crystal diffraction analysis shows that it crystallizes in the monoclinic system, space group P21/n with a = 11.480(2), b = 11.885(2), c = 12.939(3) ?, β = 110.55(3)°, V = 1653.1(6) ?3, Mr = 423.25, Dc = 0.425 g/cm3, Z = 4, R = 0.0361 and wR = 0.1011. The title complex consists of 2D 2 ∞ [Co(phen)(μ-l)3/3] layers and crystal water molecules. Each Co atom is octahedrally coordinated by three N atoms and three O atoms to form 2D 2 ∞ [Co(phen)(μ-l)3/3] polymeric layers. Furthermore, such 2D layers are stacked into 3D supramolecular frameworks via Van der Waals’ intermolecular forces, strong and weak hydrogen-bond interactions. The coordination phen and crystal water molecules are resided into cavities of the frameworks.

关键词： Co(II), pyrazine-2,3-dicarboxylic acid, 1,10-phenanthrline, 2D coordination polymer, hydrothermal synthesis, crystal structure

Dormancy release and germination of Echinochloa crus-galli grains in relation to galactomannan-hydrolysing enzyme activity

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Journal of Integrative Agriculture 2015年第8期14卷 1627-1636页

作者： song Bing-yan SHI Jin-xiao song song-quan College of Biology Resources and Environmental Sciences Jishou University Institute of Botany Chinese Academy of Sciences

Echinochloa crus-galli, one of the world＇s most serious weeds, influences seriously the yield and quality of cereal crop *** is well known that ***-galli grain is dormant, but its dormant type, as well as its dormancy release and germination in relation to galactomannan-hydrolysing enzyme activity were poorly *** cooperation of endo-β-mannanase（EC 3.***.1.78）, β-mannosidase（EC 3.***.1.25） and α-galactosidase（EC 3.***.1.22） can hydrolyze the cell walls rich in mannan-based *** the present paper, the mature grains are used as experimental materials, we investigated the water uptake of grains, the effect of removing partial endosperm, after-ripening, stratification and phytohormone on grain germination, and the change in endo-β-mannanase, β-mannosidase and α-galactosidase activities of grains during after-ripening and *** results showed that the freshly-collected grains were water-permeable and had only phase I and II of water uptake, while the grains after-ripened for 150 d had an obvious phase III of water *** alternating photoperiod, the germination of grains freshly-collected was zero at 10–35°C, and that of half grains was 11% at 20°C *** grain germination was notably promoted by after-ripening and stratification, but not by gibberellic acid and 6-benzyladenine at 0.0001–1 mmol l–1.β-Mannosidase activity increased during 0 to 300 d of after-ripening and then *** activity of endo-β-mannanase and α-galactosidase of grains decreased with *** grain germination, endo-β-mannanase and β-mannosidase activities obviously increased, while α-galactosidase activity *** data showed that ***-galli grain was a deep physiological dormant, the dormancy release by after-ripening was related to an increasing β-mannosidase activity, and its germination was closely associated with an increasing endo-β-mannanase and β-mannosidase activity; which have provided new knowledge to decrease the harm of ***

关键词： after-ripening deep physiological dormancy Echinochloa crus-galli galactomannan-hydrolysing enzyme phytohormone stratification

Preparation and Characterization of the Modified Polyvinylidene Fluoride (PVDF) Hollow Fibre Microfiltration Membrane

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Journal of Materials Science & Technology 2007年第1期23卷 55-60页

作者： laizhou song Zunju ZHang Shizhe song Zhiming GAO School of Environment ancl Chemical Engineering Yanshan University Qinhuangdao 066004 China School of Material Science and Engineering Tianjin University Tianjin 300072 China

A novel thermally induced graft polymerization technique was used to modify a polyvinylidene fluoride （PVDF） hollow fibre microfiltration membrane. An artificial neural network （ANN） was applied to optimize the prepared condition of the membrane. The optimized dosing of acrylic acid （AA）, acrylamide （AM）, N, N＇- methylenebisacrylamide （NMBA） and potassium persulphate （KSP） designed by ANN was that AA was 40.63 ml/l; AM acted as 6.25 g/l; NMBA was 1.72 g/l and KSP was 1.5 g/l, respectively. The thermal stability of the PVDF modified hollow fibre membrane （PVDF-PAA） was investigated by thermogravimetric （TG） and differential scanning calorimetry （DSC） analysis. The polycrystallinity of the PVDF-PAA membrane was evaluated by X-ray diffraction （XRD） analysis. The complex formation of the modified membrane was ascertained by Fourier transform infrared spectroscopy （FTIR）. The morphology of the PVDF-PAA membrane was studied by environmental scanning electron microscopy （ESEM）. The surface compositions of the membrane were analyzed by X-ray photoelectron spectroscopy （XPS）. The adsorption capacity of Cu^2＋ ion on the PVDF-PAA hollow fibre membrane was also investigated.

关键词： Microfiltration hollow fibre membrane Graft polymerization modification Acrylic acid Polyvinylidene fluoride Cu^2+ ion

Critical Point of Ising Films with Different Growth Directions

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Chinese Physics letters 2000年第1期17卷 55-57页

作者： Wang Huai-yu ZHOU Yun-song D.l.lin Department of Physics Yantai UniversityYantai 264005 Department of Physics Capital Normal UniversityBeijing 100037 Department of Physics State University of New York at BuffaloBuffaloNY 14260-1500U.S.A.

The critical temperature Tc of a spin-1/2 Ising film of cubic structures is calculated by the variational cumulant expansion method for three directions of *** results from different growth directions are analysed and compared with each *** the present model,the Tc values depend largely on the number of nearest neighbors in a monolayer for films with the same number of monolayers but grown in different *** sc,bcc and fee structures,the highest Tc is found along the(100),(110),and(111)direction,respectively.

关键词： directions Ising variational