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Solvothermal synthesis and ferromagnetic property of bamboo-shoot-like oriented carbon micromaterials

Chinese science Bulletin 2010年第33期55卷 3838-3841页

作者： YANG YongZhen1,2,LIU XuGuang1,3,REN WenFang1,3,QIU Li1,3 & XU BingShe1,2 1Key Laboratory of Interface science and engineering in Advanced materials(taiyuan university of technology),Ministry of Education,taiyuan 030024,china 2college of materials science and engineering,taiyuan university of technology,taiyuan 030024,china 3college of Chemistry and Chemical engineering,taiyuan university of technology,taiyuan 030024,china Key Laboratory of Interface science and engineering in Advanced materials (taiyuan university of technology) Ministry of Education Taiyuan 030024 China college of materials science and engineering Taiyuan University of Technology Taiyuan 030024 China college of Chemistry and Chemical engineering Taiyuan University of Technology Taiyuan 030024 China

Bamboo-shoot-like oriented carbon micromaterials(BOCMs)were synthesized by a solvothermal method at 450°C for 4 h using deoiled asphalt(DOA)as carbon source,toluene as solvent,ferrocene as catalyst precursor and amphiphilic triblock copolymer P123 as *** morphology and structure of the products were characterized by X-ray diffraction,field emission scanning electron microscopy,high resolution transmission electron microscopy and Fourier transform infrared *** results reveal that the obtained products have good distribution with uniform diameters of about 0.5 ?m and the lengths of 1-1.5 μm,and hydrogen-carbon bonds are observed on the surface of *** growth mechanism of BOCMs is discussed,in which that the catalysis of ferrocene and the dispersion and assembly of the aromatic molecules of DOA directed by P123 are critical to the formation of the *** coercivity value(231.91 Oe)from the measurement of a vibrating sample magnetometer shows that the BOCMs have an obvious ferromagnetic behavior.

关键词：溶剂热合成铁磁性碳源场发射扫描电子显微镜高分辨透射电子显微镜傅里叶变换红外光谱两亲嵌段共聚物振动样品磁强计

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Improving the Wear Resistance of AZ31B Magnesium Alloy by Laser Cladding with Al-Si/Al_2O_3-TiO_2 Powders

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稀有金属材料与工程 2011年第S4期40卷 169-173页

作者： Cui Zeqin1,2,Wang Wenxian1,2,Wu Hongliang1,Xu Bingshe1,2 1Key Laboratory of Interface science and engineering in Advanced materials (taiyuan university of technology),Ministry of Education,taiyuan 030024,china 2college of materials science and engineering,taiyuan university of technology,taiyuan 030024,china taiyuan Univ Technol Coll Mat Sci & Engn Taiyuan 030024 Peoples R China taiyuan Univ Technol Minist Educ Key Lab Interface Sci & Engn Adv Mat Taiyuan 030024 Peoples R China

To improve the wear resistance of magnesium alloy,the laser surface cladding of AZ31B magnesium alloy with Al-12 % Si and Al2O3-40 % TiO2 composite powders (in the wt.% ratio of 10:1,6:1,4:1) were investigated by using a 5kW continuous wave CO2 laser.A detailed microstructure and phase analysis of the surface modified layer were studied by optics microscopy(OM),scanning electron microscopy(SEM),energy dispersive spectroscopy (EDS),X-ray diffraction(XRD).The microstructure of the surface modified layers mainly consist of Al-Mg matrix,dendrite precipitates and Al2O3,TiO2 ceramic *** microhardness of the surface layer were measured and wear resistance property were evaluated in *** average microhardness of the surface layers were significantly improved to 250HV0.05 as compared with 50HV0.05 of the AZ31B *** results showed that the wear resistance of the laser surface modified samples was considerably improved as compared as the as-received specimen.

关键词： AZ31B magnesium alloy laser cladding Al-Si/Al2O3-TiO2 powders wear resistance

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Synthesis of nano onion-like fullerenes by using Fe/Al_2O_3 as catalyst by chemical vapor deposition

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Chinese science Bulletin 2009年第1期54卷 137-141页

作者： LIU XuGuang1,2,WANG CunJing1,2,YANG YongZhen1,3,GUO XingMei1,2,WEN HaiRong1,2 & XU BingShe1,3 1 Key Laboratory of Interface science and engineering in Advanced materials,Ministry of Education,taiyuan university of Tech-nology,taiyuan 030024,china 2 college of Chemistry and Chemical engineering,taiyuan university of technology,taiyuan 030024,china 3 college of materials science and engineering,taiyuan university of technology,taiyuan 030024,china Key Laboratory of Interface science and engineering in Advanced materials Ministry of Education Taiyuan University of Technology Taiyuan 030024 China college of Chemistry and Chemical engineering Taiyuan University of Technology Taiyuan 030024 China college of materials science and engineering Taiyuan University of Technology Taiyuan 030024 China

Nano-carbon materials were synthesized by the catalytic decomposition of acetylene at 400℃ by using Fe/Al2O3 as catalyst. The product was refluxed in 36% concentrated HCl at 60℃ for 48 h in order to re-move the catalyst support. The samples were examined by scanning and high resolution transmission electron microscopy,energy dispersive spectroscopy and X-ray diffraction. The results show that nano onion-like fullerenes encapsulating a Fe3C core were obtained. These had a structure of stacked graphitic fragments,with diameters ranging from 15―50 nm. When the product was further heat-treated at 1100℃ for 2 h,nano onion-like fullerenes with a clear concentric graphitic layer structure were obtained. The growth mechanism of nano onion-like fullerenes encapsulating metal cores is suggested to follow a vapor-solid growth model.

关键词：纳米碳材料化学蒸发沉积作用合成增长机制

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Crystallization in Zr_(60)Al_(15)Ni_(25) bulk metallic glass subjected to rolling at room temperature

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science china(Technological sciences) 2010年第1期53卷 278-283页

作者： YAN ZhiJie,YAN Jun,HU Yong & DANG ShuE School of materials science and engineering,taiyuan university of science and technology,taiyuan 030024,china 1. School of materials science and engineering Taiyuan University of Science and Technology Taiyuan 030024 China

The microstructure evolution of Zr60Al15Ni25 bulk metallic glass during rolling at room temperature is investigated by differential scanning calorimetry(DSC),high-resolution transmission electron microscopy(HRTEM) and selected area electronic diffraction(SAED).The HRTEM images show that shear bands are produced in the rolled specimens,indicating the essence of inhomogeneous deformation due to rolling,and that there exist nanocrystals with size of about 5-10 nm in the transition regions between the shear bands and the undeformed matrix in the rolled specimens with deformation degrees of 80% and 95%.Based on the polyhedral structure model and the shear transformation zone(STZ) theory,the influence of viscous flow,free volume,viscosity and the stress situation on the crystallization behaviors in the metallic glass during rolling is discussed.

关键词： metallic glasses plastic deformation nanocrystallization free volume

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Effects of lanthanum on calcium-activated K^+ currents and its kinetics in MC3T3 cells

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science china Chemistry 2010年第6期53卷 1281-1286页

作者： ZHANG LiPing1,2 & YANG Pin1 1Key Laboratory of Chemical Biology and Molecular engineering of Ministry of Education Institute of Molecular science,Shanxi university,taiyuan 030006,china 2college of Environment and Safety,taiyuan university of science and technology,taiyuan 030024,china 1. Key Laboratory of Chemical Biology and Molecular engineering of Ministry of Education Institute of Molecular science Shanxi University Taiyuan 030006 China2. College of Environment and Safety Taiyuan University of Science and Technology Taiyuan 030024 China

Using the whole cell patch-clamp technique,we studied the effects of La3+ on calcium-activated K+ currents and its kinetics of activation and inactivation in non-excitable MC3T3 *** results showed that the calcium-activated outward K+ currents were promoted with increasing concentration of Ca2+ in the pipette solution and a voltage- and Ca2+-dependent ***3+ in the bath solution inhibited the currents in a concentration-dependent manner and the inhibition EC50 was 8.23 ± 1.45 μmol/*** the concentration of 50 μmol/L,La3+ significantly changed the Vh of the activation curve and shifted the activation curve to more positive potentials,but shifted the inactivation curve to more negative *** had no effect on the slope factor k of the activation and inactivation *** currents inhibition could induce a series of physiological and molecular biological functions,presumably because of its ability to depolarize the plasma membrane and enhance cell excitability,resulting in increasing Ca2+ influx and cytoplast Ca2+ *** process may be one of the molecular mechanisms by which La3+ affects the cell growth and function of MC3T3 cells.

关键词： MC3T3 cell potassium ion channel La3+ patch-clamp technique

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Study on Characteristics and Generation Mechanism of YAG Pulsed Laser Welding Cracks of AZ31B Magnesium Alloy

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稀有金属材料与工程 2011年第S4期40卷 21-25页

作者： Cui Zeqin1,2,Wang Wenxian1,2,Si En1,Xu Bingshe1,21Key Laboratory of Interface science and engineering in Advanced materials (taiyuan university of technology),Ministry of Education,Tai-yuan 030024,china2college of materials science and engineering,taiyuan university of technology,taiyuan 030024,china taiyuan Univ Technol Coll Mat Sci & Engn Taiyuan 030024 Peoples R China taiyuan Univ Technol Key Lab Interface Sci & Engn Adv Mat Minist Educ Taiyuan 030024 Peoples R China

Due to poor metallurgical weldability of magnesium alloy,laser welding crack is still one of the main *** generations of welding crack seriously affected the weld quality and reduce the mechanical properties of welded joints which have become a bottleneck of the magnesium alloy products widely used in the structure *** this paper,AZ31B magnesium alloy sheet with 2mm thickness was used for this *** forming reason and extending characteristics of the welding cracks were investigated during the Nd:YAG pulsed laser *** results show that welding cracks are mainly solidification crack which were always present in the weld *** welding hot cracks appear multiple furcation phenomenons,and main and branch cracks were intercrystalline *** partial branch crack was mixed intercrystalline and transgranular *** addition,few cracks in the weld were caused due to irregular shape porosity and *** delayed crack weren't observed in the weld after deposited 48 *** the pre-process on the basis,the characteristics and generation mechanism of YAG pulsed laser welding cracks of magnesium alloy were analyzed further.

关键词： AZ31B magnesium alloy Nd:YAG pulsed laser laser welding welding crack crack extension

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Microstructural Evolution of Surface Layer of TWIP Steel Deformed by Mechanical Attrition Treatment

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Journal of Iron and Steel Research International 2012年第3期19卷 38-46页

作者： LI Da-zhao1,2, WEI Ying-hui1, HOU Li-feng1, LIN Wan-ming1 (1. college of materials and engineering, taiyuan university of technology, taiyuan 030024, Shanxi, china 2. college of materials and engineering, North university of china, taiyuan 030051, Shanxi, china) [a] college of materials and engineering Taiyuan University of Technology Taiyuan 030024 Shanxi China [b] college of materials and engineering North University of China Taiyuan 030051 Shanxi China

A nanocrystalline layer was synthesized on the surface of TWIP steel samples by surface mechanical attri- tion treatment （SMAT） under varying durations. Microhardness variation was examined along the depth of the de- formation layer. Microstructural characteristics of the surface at the TWIP steel SMATed for 90 min were observed and analyzed by optical microscope, x-ray diffraction, transmission and high-resolution electron microscope. The re- sults show that the orientation of austenite grains weakens, and a-martensite transformation occurs during SMAT. During the process of SMAT, the deformation twins generate and divide the austenite grains firstly~ then a-martens- ite transformation occurs beside and between the twin bundles~ after that the martensite and austenite grains rotate to accommodate deformation, and the orientations of martensite and between martensite and residual austenite increase; lastly the randomly oriented and uniform-sized nanocrystallir^e layers are formed under continuous deformation.

关键词： SMAT technology twinning stacking fault energy deformation twin

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Simulation of the Backward Flow of the Melted Pool into the Laser Keyhole

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稀有金属材料与工程 2011年第S4期40卷 35-38页

作者： Wang Hong,Huo Houzhi,Wang Lingyun School of Material science and engineering,taiyuan university of science and technology,taiyuan 030024,china taiyuan Univ Sci & Technol Sch Mat Sci & Engn Taiyuan 030024 Peoples R China

When laser beam is ceased,the melt metal flows downward to fill the keyhole during keyhole *** models and VOF(volume of fluid)techniques have been developed to study the refilling *** simulation results show that the surface tension pressure plays more important role than the total pressure of fluid flow in the molten pool,and the violent interaction between liquid metal and keyhole air and whirlpool in the fluid flow influence the dimension of keyhole air region and the velocity of molten pool.

关键词： laser welding molten pool simulation

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Effect of the Deformation Twin Density on the Corrosion Behavior in TWIP Steel

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Journal of Iron and Steel Research International 2011年第S1期18卷 331-336页

作者： CHU Guo-dong,WEI Ying-hui,LI Da-zhao,TIAN Yun (college of materials science and engineering,taiyuan university of technology,taiyuan 030024,Shanxi,china) taiyuan Univ Technol Coll Mat Sci & Engn Taiyuan 030024 Shanxi Peoples R China

Based on its excellent tensile strength-ductility property combination,twinning-induced plasticity (TWIP) steel shows great potential in applications for structural components in automobile *** aim of this research is to investigate the corrosion resistance properties and corrosion mechanism under room temperature in TWIP *** influence of the deformation twin density on corrosion property was primarily considered by salt spray *** specimens used in the investigation are as-annealed and as-deformed *** microstructure and corrosion resistance property were characterized by scanning electron microscope (SEM),optical microscope (OM) and so *** are some annealing twins distributed randomly in austenitic grains in the as-annealed *** the specimen was subjected to tensile experiment,the density of the deformation twins increased sharply,which are different from the annealing twins in size and *** was found that the corrosion potential of the as-annealed is lower than that of the as-deformed and the corrosion current density behaves *** immersed in 5% NaCl solution salt spray for 48h,the as-deformed showed a bit better than the as-annealed in corrosion *** the time prolonged,the gap between the two specimens in corrosion resistance increased *** corrosion morphologies varied in color and *** investigation,carried out by SEM and EDS,indicated that as-annealed and the as-deformed followed pitting corrosion and uniform corrosion mechanism *** reason for the difference in corrosion mechanism is possibly the presence of the deformation *** deformation twins formed during the tensile test refine grains by way of *** twin boundaries largely belong to the coincidence site lattice (CSL),which is on lower energy *** suggests that the twins not only play a role in strengthening,but also improve effectively the corrosion resistance in TWIP steel.

关键词： TWIP steel corrosion deformation twin

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V_2O_5/C catalyst for liquid phase oxidation of glyoxal to glyoxylic acid

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science china Chemistry 2009年第7期52卷 1057-1062页

作者： NIU YuLan1,2 & LI RuiFeng1 1 Key Laboratory of Coal science and technology, Ministry of Education, Institute of Special Chemicals, taiyuan university of technology, taiyuan 030024, china 2 Department of Chemical engineering, taiyuan Institute of technology, taiyuan 030008, china Key Laboratory of Coal science and technology Ministry of Education Institute of Special Chemicals Taiyuan University of Technology Taiyuan 030024 China Department of Chemical engineering Taiyuan Institute of Technology Taiyuan 030008 China

A study of the catalytic activity of V2O5/C catalyst for the oxygen oxidation of glyoxal has been made, showing that glyoxylic acid can be formed without control of pH value and there is little oxalic acid from the excessive oxidation of glyoxylic acid. The studies of XRD and TEM have shown that V2O5 diffraction peaks gradually strengthen with the increase of the content of V2O5. With the content of 3% V2O5 and the calcination temperature of 573 K, V2O5/C catalyst displayed the best activity and selectivity. The conversion of glyoxal and the selectivity of glyoxylic acid reached 18.76% and 77.70% after 5 h, respectively. Moreover, V2O5/C catalyst showed small deactivation after recycling three times, which indicates that V2O5/C has a higher stability than noble metal catalysts in the reaction medium.

关键词： glyoxal glyoxylic acid V2O5/C catalyst

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