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Science china(Technological Sciences) 2009年第4期52卷 857-863页

作者： WANG Qiang, WANG ZhongYing, LIU Tie, WANG ChunJiang, ZHANG Chao & HE JiCheng key laboratory of Electromagnetic Processing of materials (ministry of education), Northeastern university, Shenyang 110004, china key laboratory of Electromagnetic Processing of materials (ministry of education) Northeastern University Shenyang China

Al-Ni hypereutectic alloys with various compositions were solidified under various magnetic field con- ditions to investigate the alignment of primary Al3Ni phases. The results showed that the application of high magnetic fields could improve the homogeneity of the primary Al3Ni phase distribution and induce the alignment of primary Al3Ni phases in the direction perpendicular to the magnetic field direction to form chain-like structures. However, the alignment was different from the orientation of the Al3Ni phases. Furthermore, the degree of the alignment decreased with the increasing concentration of Ni element. This can be attributed to the combination effects of high magnetic field and alloy composition on the concentration field around the crystallized primary Al3Ni crystals.

关键词： high magnetic fields alloy composition primary Al3Ni phase alignment solidification

THREE-DIMENSIONAL CHARACTERISTICS AND HOMOGENIZATION OF ELECTROmagnetic FIELD IN SOFT-CONTACT CONTINUOUS CASTING MOLD

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Acta Metallurgica Sinica(English Letters) 2001年第2期14卷 137-142页

作者： A. Y. Deng, G.L. Jia and J.C. He (key laboratory for Electromagnetic Processing of materials, ministry of education, Northeastern university, Shenyang 110004, china) Northeast Univ. Shengyang 110004 China

The three-dimensional electromagnetic characteristics and non-uniform distribution of electromagnetic field in soft-contact continuous casting mold have been analyzed by numerical simulation. The results show that the maximum electromagnetic flux density is found in front of slit; the electromagnetic flux density becomes large as the coil current and slit number increase. In a certain frequency range, the electromagnetic flux density increases with the increase of frequency and the frequency range is different with the change of azimuthal position along the inner wall of mold. The uniformity of electromagnetic field is influenced mainly by frequency and mold structure parameters. Increasing slit number and adjusting slit arrangement position can improve the electromagnetic flux density and the uniformity of electromagnetic field. For a soft-contact mold with 16 slits, when frequency is 20 kHz, the optimal slit arrangement parameter is a:b=1:2, c=0.

关键词： Computer simulation Electromagnetic fields magnetic properties Molds Optimization Three dimensional

Effect of annealing on the microstructures and Vickers hardness at room temperature of intermetallics in Mo-Si system

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Rare Metals 2004年第2期23卷 176-181页

作者： YANG Haibo LI Wei SHAN Aidang WU Jiansheng key laboratory of ministry of education for High Temperature materials and Tests & Department of Material Science and Engieering, Shanghai Jiao Tong university, Shanghai 200030, china 上海交通大学教育部高温材料及高温测试开放实验室上海 200030

The microstructures and Vickers hardness at room temperature of arc-meltingprocessed intermetallics of Mo_5Si_3-MoSi_2 hypoeutectic alloy and hypereutectic alloy annealed at1200℃ for different time were investigated. Lamellar structure consisted of Mo_5Si_3 (D8m) phaseand MoSi_2 (C11_b) phase was observed in all the alloys. For Mo_5Si_3-MoSi_2 hypoeutectic alloy, thelamellar structure was found only after annealing and developed well with fine spacing on the orderof hundred nanometers after annealing at 1200℃ for 48 h. But when the annealing time was up to 96h, the well-developed lamellar structure was destroyed. For Mo_5Si_3-MoSi_2 hypereutectic alloy, thelamellar structure was found both before and after annealing. However the volume fraction andspacing of the lamellar structure did not change significantly before and after annealing. Theeffects of the formation, development and destruction of lamellar structure on Vickers hardness ofalloys were also investigated. When Mo_5Si_3-MoSi_2 hypoeutectic alloy annealed at 1200℃ for 48 h,the Vickers hardness was improved about 19% compared with that without annealing and formation oflamellar structure. The highest Vickers hardness of Mo5Si3-MoSi_2 hypereutectic was increasing about18% when annealing at 1200℃ for 48 h.

关键词： material experiment lamellar structure microstructure vickers hardness anneal intermetallics Mo-Si system

Preparation and characterization of CoFe_2O_4/TiO_2 magnetic composite films

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Science china Chemistry 2008年第9期51卷 842-847页

作者： TIAN XiaoXia1, QU ShaoBo1,2, PEI ZhiBin1 & WANG BinKe1,2 1 College of Science, Air Force Engineering university, Xi’an 710051, china 2 Electronic materials Research laboratory, key laboratory of ministry of education, Xi’an Jiaotong university, Xi’an 710049, china College of Science Air Force Engineering University Xi’an China Electronic materials Research laboratory Key Laboratory of Ministry of Education Xi’an Jiaotong University Xi’an China

CoFe2O4/TiO2 magnetic composite films were prepared using the sol-gel method with tetrabutyltitanate and metallic chlorates as starting materials. The effects of heat treatment temperatures on micro- structures and on magnetic properties were studied. The microstructure and properties of the samples at different heat treatment temperatures were characterized by X-ray diffraction, Raman spectrum, scanning electron microscopy, polarized microscopy and vibrating sample magnetometry. The results show that crystals of different substances grow up independently. Cobalt ferrite is evenly embedded into the titanium dioxide matrix in the prepared composite films. The magnetism of the composite films is enhanced with an increase of the heat temperature.

关键词： CoFe2O4/TiO2 composite films magnetism sol-gel

magnetism induced by nonmagnetic dopants in zinc-blende SiC: First-principle calculations

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Science china(Physics,Mechanics & Astronomy) 2010年第1期53卷 1-10页

作者： LIU ZhaoQing & NI Jun Department of Physics and key laboratory of Atomic and Molecular Nanoscience (ministry of education), Tsinghua university, Beijing 100084, china Department of Physics and key laboratory of Atomic and Molecular Nanoscience (ministry of education) Tsinghua University Beijing China

magnetism induced by the nonmagnetic dopants in the zinc-blende SiC (3C-SiC) is investigated by first-principle calculations. The atoms of the first 20 elements in the periodic table except inert gas are used to replace either Si or C atoms as dopants. We find that some nonmagnetic substitutional dopants (mainly the Group IA, Group IIA, Group IIIB, and Group VIIB elements) prefer the spin-polarized ground states with local magnetic moments. In general, the condition for obtaining the local magnetic moments and the magnetic ground state requires that the dopants are p-type and have large electronegativity difference from the neighboring host atoms. The magnetic moments can be tuned over a range between 1 μ B and 3 μ B by doping with the nonmagnetic elements. The nearest-neighbor exchange couplings J 0 between the local magnetic moments are quite large and the codoping method is proposed to increase the dopant concentration. These imply that the nonmagnetic doping in SiC may exhibit collective magnetism. Moreover, the Group IIA Mg and Ca atoms substituting the preferred Si atoms favor the ferromagnetic ground states with the half-metallic electronic properties, which suggests that Mg or Ca substitutional doping on the Si sites in SiC could be a potential route to fabricating the diluted magnetic semiconductors.

关键词： nonmagnetic dopant magnetism SiC diluted magnetic semiconductor first-principle calculation

Flexural and Impact Resistance of FRC/Bamboo Laminate

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Journal of materials Science & Technology 2002年第4期18卷 369-371页

作者： Wu YAOState key laboratory of Concrete materials Research, Tongji university, Shanghai 200092, china Lab. of Concrete Mat. Res. Tongji Univ. Shanghai 200092 China

The flexural and impact resistance of a newly developed FRC/bamboo laminate have been investigated. The laminate considered in this study was combined with reformed bamboo plate and extruded fiber reinforced cementitious (FRC) sheet. Innovated from the raw bamboo, reformed bamboo showed high tensile strength and high strength to weight ratio. It can not only remarkably strengthen the FRC sheet but also reduce the total weight of the laminate. Flexural and impact load, broken energy, deflection and duration were measured. Test results showed that the flexural strength value for the laminate can be improved to greater than 90 MPa, while the impact resistance is increased more than 10 times for the laminate when compared with the FRC sheet only.

关键词： Flexural strength Impact FRC/bamboo composite

Influence of Additives on the Formation of Electrodeposits in the Concrete Cracks

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Journal of Wuhan university of Technology(materials Science) 2011年第2期26卷 367-371页

作者：储洪强 key laboratory of Advanced Civil Engineering materials Ministry of EducationTongji University College of Mechanics and materials Hohai University

The electrodeposition method for rehabilitation of the cracked reinforced concrete,based on the electrochemical technique,was presented *** aim of this study was to evaluate the influence of additive on the formation of electrodeposits in the concrete *** mortar specimens of size 40 mm×40 mm×160 mm were immersed in electrolyte solutions（ZnSO4,MgSO4）,and a constant current was applied between the reinforced steel and the external electrode for 15 *** of surface coating,rate of crack closure and rate of crack filling depth were measured and the appearance of electrodeposits in the cracks was *** experimental results demonstrate that,under the experimental conditions,rate of surface coating and crack filling depth increase,while rate of crack closure decreases as the percengtage of additive *** addition,the electrodeposits become more denser and the microstructure varies with additive content,while the compositions of electrodeposits do not change.

关键词： repair of cracks additive formation microstructure

Preparation, Properties and Characterization of Modified CeO_2/La_2Zr_2O_7 Buffer Layers

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稀有金属材料与工程 2011年第S3期40卷 350-353页

作者： Cheng Yanling, Suo Hongli, Liu Min, Ma Lin, Zhang Teng key laboratory of Advanced Functional materials, ministry of education, Beijing university of Technology, Beijing 100124, china Beijing Univ Technol Coll Mat Sci & Engn Minist Educ Key Lab Adv Funct Mat Beijing 100124 Peoples R China

The metal organic deposition (MOD) method was used for the epitaxial growth of the CeO2/La2Zr2O7(LZO)/LZO seed layer structure on a cube-textured Ni5W substrate layer by layer. The material phase and the macro-orientations were analyzed by XRD. The surface morphology and the blocking performance of the buffer layer were investigated by SEM and AES. The grain orientation and the crystallographic growth mode of the CeO2 layer were first characterized by electron backscattering diffraction (EBSD). The uniformly distributed islanded LZO seed layer optimized both the in-plan and the out-plan orientation of the CeO2/LZO buffer layers, and the CeO2/LZO buffer layers with a thickness of 175 nm acted as an efficient Ni,W barrier. The EBSD analysis indicated that the crystallographic orientation of each layer can be obtained at various accelerating voltages for the multilayer sample, the percentage of {001} rotated cube texture of CeO2 layer reaching 97.4% at the accelerating voltage of 15 kV, thus showing epitaxial deposition with a high texture.

关键词： coated conductor buffer layer La2Zr2O7 seed layer CeO2 rotated cube texture accelerating voltage

Progress in the studies of low-molecular mass gelators with unusual properties

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Science china Chemistry 2011年第4期54卷 575-586页

作者： LIU KaiQiang,HE PanLi & FANG Yu key laboratory of Applied Surface and Colloid Chemistry (Shaanxi Normal university),ministry of education School of Chemistry and materials Science,Shaanxi Normal university,Xi’an 710062,china key laboratory of Applied Surface and Colloid Chemistry (Shaanxi Normal university) Ministry of Education School of Chemistry and materials Science Shaanxi Normal University Xi’an China

This article is intended to provide an overview of recent progress in the studies of cholesterol-based low-molecular mass gelators (LMMGs) with unusual properties,in particular,gelation and selective gelation at room temperature,gel emulsions and gel film formation,*** applications of the LMMGs in spilled oil collection and water purification are briefly presented.

关键词： gelation at room temperature selective gelation gel emulsions gel films

Morphology and Mssbauer studies of CoFe2O4 nanofibers synthesized by electrospinning

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Morphology and Mssbauer studies of CoFe2O4 nanofibers synt...