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Electronic structure and magnetic properties of SmCo7-xTix

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Science china(Physics,Mechanics & Astronomy) 2006年第1期49卷 38-45页

作者： ZHANG Changwen1, LI Hua1, DONG Jianmin1, GUO Yongquan2 & LI Wei2 1. School of Physics and Microelectronics, shandong University, jinan 250100, china 2. institute of Functional Materials, Central Iron and Steel research institute, Beijing 100081, china School of Physics and Microelectronics Shandong University Jinan China institute of Functional Materials Central Iron and Steel Research Institute Beijing China

Electronic structure of SmCo7-xTix alloy has been studied by means of the spin-polarized MS-Xα method. It is shown that a few of electrons are transferred to Sm(5d) orbital due to orbital hybridization between Sm and Co atoms. The exchange interaction between 5d-3d electrons is stronger, which is the main reason resulting in the long-range ferromagnetic order between Co and Sm atoms. The Curie temperature of SmCo7-xTix is generally lower than that of pure Co metal, which may be explained by the weaker aver- age of coupling strength between Co sites due to some negative exchange couplings occurring mainly at 2e site. The calculated results for the Sm5Co28Ti6 cluster may lead to a better understanding of why SmCo7-xTix is stable phase. Since the negative interaction of 2e sites weakens and the bonding at EF strengthens with increasing Ti concentration, which result in the decrease in the free energy of the alloy, the stable ferromagnetic order forms inside SmCo7-xTix. Considering the localization of 4f states and 5d moment arising from the orbital hybridization, the calculated moment is 9.47μB per formula unit that is in agreement with experiments.

关键词： electronic structure, spin polarization, atomic magnetic moment, exchange coupling, Curie temperature.

An exact solution for flow past an accelerated horizontal plate in a rotating fluid with the generalized Oldroyd-B model

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Acta Mechanica Sinica 2009年第4期25卷 463-469页

作者： Jianhong Kang Mingyu Xu institute of Applied Mathematics,School of Mathematics and System Science,shandong University, 250100 jinan, china institute of Applied Mathematics School of Mathematics and System Science Shandong University Jinan China

In this paper, the generalized Oldroyd-B with fractional calculus approach is used. An exact solution in terms of Fox-H function for flow past an accelerated horizontal plate in a rotating fluid is obtained by using discrete Laplace transform method. A comparison among the influence of various parameters in the Oldroyd-B model and the angular velocity of the fluid on the velocity profiles is made through numerical method in graphic form.

关键词： Generalized Oldroyd-B model Rotating fluid Accelerated plate Exact solution

Influence of Heating Rate on Double Reversible Transformation in CuZnAlMnNi Shape Memory Alloy

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Rare Metals 2001年第2期20卷 117-120页

作者： Yujun Bai, Chengwei Lu, Xiangang Xu, Guili Geng, Longwei Yin (Mechanical Department, shandong University of Science and Technology, jinan 2.003., china institute of Materials Science and Engineering, shandong University, jinan 250061, china) 山东理工大学山东济南 250031 山东大学山东济南 250061

The influence of heating rate on double reversible transformation in CuZnAlMnNi shape memory alloy was investigated by differential scanning calorimetry. It was found that rapid heating inhibits X -->M transformation but is favorable to the reverse martensite transformation, giving rise to the approach of the two transformation peaks. With the decrease of heating rate, the two transformation peaks separate gradually.

关键词： double reversible transformations heating rate CuZnAlMnNi shape memory alloy differential scanning calorimetry

Transparent Conducting ZnO:Al Films on Different Organic Substrates Deposited by r.f. Sputtering

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Journal of Materials Science & Technology 2000年第1期16卷 23-26页

作者： Yuan CHEN, Deheng ZHANG and Qingpo WANG (Department of Physics, shandong University, jinan 250100, china) Jin MA and Tianlin YANG (institute of Optoelectronic Materials and Devices, shandong University, jinan 250100, china) Department of Physics Shandong University Jinan 250100 China institute of Optoelectronic Materials and Devices Shandong University Jinan 250100 China

Transparent conducting ZnO:AI films with good adhesion, low resistivity and high transmittance have been prepared on polyptopylene adipate (PPA), polyisocyanate (PI) and polyester substrates by r.f. magnetron sputtering. The structural, electrical and optical properties of the obtained films were studied. The polycrystalline ZnO:AI films with resistivity as low as 5.76xl0^-4 Ω.cm, carrier concentration 9.06xl0^20 cm^-3 and Hall mobility 11.98 cm^2 V^-1s^-1 were produced on PPA substrate by controlling the deposition parameters. The average transmittance of films on PPA is ～80% in the wavelength range of visible spectrum. The films on PPA substrates have better electrical and optical properties compared with the films on other kinds of substrates.

关键词： ZnO Sputtering Transparent Conducting ZnO Al

Elastic-plastic contact force history and response characteristics of circular plate subjected to impact by a projectile

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Acta Mechanica Sinica 2007年第4期23卷 415-425页

作者： L.B.Chen F.Xi J.L.Yang Solid Mechanics research Center,Beihang University,Beijing 100083.china shandong institute of Architecture and Engineering,jinan 250014,china Solid Mechanics research Center Beihang University Beijing China shandong institute of Architecture and Engineering Jinan China

A new elastic-plastic impact-contact model is proposed in this paper. By adopting the principle of minimum acceleration for elastic-plastic continue at finite deformation, and with the aid of finite difference method, the proposed model is applied in the problem of dynamic response of a clamped thin circular plate subjected to a projectile impact centrally. The impact force history and response characteristics of the target plate is studied in detail. The theoretical predictions of the impact force and plate deflection are in good agreements with those of LDA experimental data. Linear expressions of the maximum impact force/transverse deflection versus impact velocity are given on the basis of the theoretical results.

关键词： Elastic-plastic contact model ImpactCircular plate Contact force Minimum principleof acceleration

Fabrication of hexagonal gallium nitride films on silicon (111) substrates

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Rare Metals 2003年第3期22卷 221-225页

作者： YANGLi XUEChengshan WANGCuimei LIHuaixiang RENYuwen ChemistryFunctionMaterialsLab InstituteofSemiconductorsShandongNormalUniversityJinan250014China PhysicsDe0artment ShandongNormalUniversityJinan250014China InspectioninstituteforElectronicProductsofshandong Jinan250000China

Hexagonal gallium nitride films were successfully fabricated throughammoniating Ga_2O_3 films deposited on silicon (111) substrates by electrophoresis. The structure,composition, and surface morphology of the formed films were characterized by X-ray diffraction(XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmissionelectron microscopy (TEM). The measurement results reveal that the polycrystalline GaN films withhexagonal wurtzite structure were successfully grown on the silicon (111) substrates. Preliminaryresults suggest that varying the ammoniating temperature has obvious effect on the quality of theGaN films formed with this method.

关键词： semiconductor materials GaN films electrophoresis Ga_2O_3

Function of the iron-binding chelator produced by Coriolus versicolor in lignin biodegradation

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Science china(Life Sciences) 2008年第3期51卷 214-221页

作者： WANG Lu1, YAN WenChao1, CHEN JiaChuan2, HUANG Feng1,2 & GAO PeiJi1 1 State Key Laboratory of Microbial Technology, shandong University, jinan 250100, china 2.shandong Key Lab of Pulp and Paper Engineering, shandong institute of Light Industry, jinan 250100, china State Key Laboratory of Microbial Technology Shandong University Jinan China shandong Key Lab of Pulp and Paper Engineering Shandong Institute of Light Industry Jinan China

An ultrafiltered low-molecular-weight preparation of chelating compounds was isolated from a wood-containing culture of the white-rot basidiomycete Coriolus versicolor. This preparation could chelate Fe3+ and reduce Fe3+ to Fe2+, demonstrating that the substance may serve as a ferric chelator, oxygen-reducing agent, and redox-cycling molecule, which would include functioning as the electron transport carrier in Fenton reaction. Lignin was treated with the iron-binding chelator and the changes in structure were investigated by 1H-NMR, 13C-NMR, difference spectrum caused by ionization under alkaline conditions and nitrobenzene oxidation. The results indicated that the iron-binding chelator could destroy the β-O-4 bonds in etherified lignin units and insert phenolic hydroxyl groups. The low-molecular-weight chelator secreted by C. versicolor resulted in new phenolic substructures in the lignin polymer, making it susceptible to attack by laccase or manganese peroxidase. Thus, the synergic action of the iron-binding chelator and the lignocellulolytic enzymes made the substrate more acces- sible to degradation.

关键词： Coriolus versicolor lignin degradation iron binding chelator

Effects of Raloxifene on Caveolin-1 mRNA and Protein Expressions in Vascular Smooth Muscle Cells

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Acta Biochimica et Biophysica Sinica 2006年第11期38卷 747-752页

作者： Fa-Lin YANG~(1#*) Hong HE~(2#) Xian-Xi LIU~1* Bing TU~1 Xian-Wei ZENG~3 Ji-Xin SU~1 Xin WANG~2 Qin HU~2 1 institute of Biochemistry and Molecular Biology,Medical College,shandong University,jinan 250012,china 2 Department of Cardiology,Qilu Hospital,shandong University,jinan 250012,china 3 Department of Clinical Medicine,Weifang Medical College,Weifang 260041,china institute of Biochemistry and Molecular Biology Medical College Shandong UniversityJinan 250012 China Department of Cardiology Qilu Hospital Shandong UniversityJinan 250012 China Department of Clinical Medicine Weifang Medical CollegeWeifang 260041 China

Caveolin-1 is regulated by estrogen in vascular smooth muscle ***,a selectiveestrogen receptor modulator that possibly has cardioprotective properties without an increased risk of canceror other side effects of estrogen,may be used in women with risk of coronary artery ***,therelationship between raloxifene and caveolin-1 is still ***,this study was designed to seewhether raloxifene regulates caveolin-1 expression and if so,whether such regulation is mediated by *** aortic smooth muscle cells were cultured in the absence or presence of raloxifene (10-8to10-6M) for 12 or 24 *** mRNA and protein levels of caveolin-1 were increased significantly after 24 htreatment with *** increases were inhibited by estrogen receptor antagonist ICI 182780 (10-5M).Results of this study suggest that raloxifene stimulates caveolin-1 transcription and translation throughestrogen receptor mediated mechanisms.

关键词： raloxifene caveolin-1 estrogen receptor vascular smooth muscle cell

Electronic structure and magnetic properties of metastable SmCo_(7) compound

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Science china(Physics,Mechanics & Astronomy) 2005年第3期48卷 325-335页

作者： ZHANG Changwen 1 , LI Hua 1 , DONG Jianmin 1 , WANG Yongjuan 1 , PAN Fengchun 1 , ZHANG Jian 1 , GUO Yongquan 2 & LI Wei 2 1. School of Physics and Microelectronics, shandong University, jinan 250100, china 2. institute of Functional Materials, Central Iron and Steel research institute, Beijing 100081, china School of Physics and Microelectronics Shandong University Jinan China institute of Functional Materials Central Iron and Steel Research Institutes Beijing China

The electronic density of states, spin-splittings and atomic magnetic moments of SmCo 7 compound have been studied using spin-polarized MS-Xα method. The results show that a few of electrons are transferred to Sm(5d 0 ) orbital because of orbital hybridization between Sm and Co atoms in the compound. The exchange interactions between 3d and 5d electrons lead to the magnetic coupling between Sm and Co, and therefore, result in the long-range ferromagnetic order inside the SmCo 7 compound. There are negative exchange couplings occurring at some levels, which weakens the strength of average coupling around Co lattice. So, the Curie temperature and Co-moment of SmCo 7 decrease distinctly compared with pure Co. Compared with SmCo 5 compound, the disordered substitution of Co-Co “dumbbell-atom” pairs for Sm changes the local environment of Co lattice, which makes the 2e site bear negative magnetic moment. The strength of hybridization near Fermi level weakens and the free energy of the compound increases obviously. Thus, SmCo 7 is a metastable compound at room temperature. Considering the localization of 4f electrons and a few of 5d electrons arising from the orbital hybridization, the magnetic moment of Sm atom will be 1.61μ B in SmCo 7 compound, which is in agreement with the experimental values of Sm 3+ ion- moment and Sm atom-moment in metals.

关键词： electronic structure, spin polarization, atomic magnetic moment, exchange coupling, Curie temperature.