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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 {2.,taiyuan university of science and technology,taiyuan 03002.,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

Chemical Extraction Preparation of Delithiated Cathode materials of Li-ion Battery

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Journal of Wuhan university of technology({2. science) 2009年第6期24卷 863-866页

作者：闫时建 school of materials {2. and engineering Taiyuan University of Science and Technology

A method of conventional chemical reaction to prepare delithiated cathode materials of Li-ion battery was introduced. The cathode material of Li-ion battery was mixed with oxidizing agent Na2.2.8 in water solution, and the solution was stirred continuously to make the chemical reaction proceed sufficiently, then the reaction product was filtered and finally the insoluble delithiated cathode material was obtained. A series of tests were conducted to verify the composition, crystal structure and electrochemical property of the delithiated cathode materials were all desirable. This method overcomes the shortcomings of battery charging preparation and chemical extraction preparation employing other oxidizing agents.

关键词： chemical extraction delithiated cathode material Li-ion battery

Phase transition in the Zr_(60)Al_(15)Ni_(2.) bulk metallic glass subjected to rolling at room temperature

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science china(Technological sciences) 2006年第6期49卷 655-662页

作者： YAN Zhijie1, 2. LI Jinfu1, ZHOU Yaohe1 & WU Yanqing3 1. State Key Laboratory of Metal Matrix Composites, school of materials {2. and engineering, Shanghai Jiao Tong university, Shanghai 2.0030, china 2. school of materials science and engineering, taiyuan university of science and technology, taiyuan 03002., china 3. school of Environmental {2. and engineering, Shanghai Jiao Tong university, Shanghai 2.0030, china State Key Laboratory of Metal Matrix Composites School of Materials Science engineering Shanghai Jiao Tong University Shanghai 200030 China school of materials {2. engineering Taiyuan University of Science technology Taiyuan 030024 China school of Environmental science engineering Shanghai Jiao Tong University Shanghai 200030 China

The microstructure evolution of the Zr60Al15Ni2. metallic glass during rolling at room temperature is investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC); high-resolution transmission electron microscopy (HREM). The results show that the values of full width at half maximum (FWHM) of the XRD patterns; exothermic enthalpy ΔH of DSC plots do not monotonically change with the variation of deformation degrees . As is not large than 2.%, the values of FWHM; ΔH are lower than that of the as-cast state. When reaches 30%, the values of FWHM; ΔH become larger than that of the as-cast state, while their values begin to decrease again as reaches about 85%. These results indicate that the reversible transitions between ordered; disordered atomic configurations occur during rolling, which is further verified by the HREM images. The reversible phase transition can be explained by the competition between the diffusion controlled reordering; shear-induced disordering during rolling.

关键词： metallic glasses, plastic deformation, phase transformations, shear bands.

Effects of Cu^(2.) on characteristic of SV currents

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science china Chemistry 2006年第6期49卷 560-564页

作者： ZHANG Liping1,2.& YANG Pin1 1. Key Laboratory of Chemical Biology and Molecular engineering of Ministry of Education, Institute of Molecular science, Shanxi {2., taiyuan 030006, china 2. Institute of Environment science, taiyuan university of science and technology, taiyuan 03002., china 1. Key Laboratory of Chemical Biology and Molecular engineering of Ministry of Education Institute of Molecular Science Shanxi University Taiyuan 030006 China 2. Institute of Environment science Taiyuan University of Science and Technology Taiyuan 030024 China

Applying the patch-clamp technique to vacuoles from Radish we studied the effects of Cu2. on Slow Vacuolar (SV) current’s characteristic. Our results show that Cu2. in bath solution at higher concentration inhibits SV currents and the percentage of inhibition increases with increasing concentration and changes with different voltage. When at lower concentration, Cu2. significantly promotes the SV currents and the promotion ratio decrease with increasing voltage. At the same time, the time constants of activation become lesser after adding Cu2.. These results show that there may be some Cu2. binding sites on SV channels and binding to which can change SV current’s characteristic.

关键词： the patch-clamp technique, vacuolar, Cu2., SV channel.

Synthesis of nano onion-like fullerenes by using Fe/Al_2._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 {2.,Ministry of Education,taiyuan university of Tech-nology,taiyuan 03002.,china 2.College of Chemistry and Chemical engineering,taiyuan university of technology,taiyuan 03002.,china 3 College of {2. science and engineering,taiyuan university of technology,taiyuan 03002.,china Key Laboratory of Interface science and engineering in Advanced {2. 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 {2. Taiyuan University of Technology Taiyuan 030024 China

Nano-carbon materials were synthesized by the catalytic decomposition of acetylene at 400℃ by using Fe/Al2.3 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

Improving the Wear Resistance of AZ31B Magnesium Alloy by Laser Cladding with Al-Si/Al_2._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 {2. (taiyuan university of technology),Ministry of Education,taiyuan 03002.,china 2.ollege of {2. science and engineering,taiyuan university of technology,taiyuan 03002.,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 Al2.3-40 % 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 Al2.3,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 2.0HV0.05 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/Al2.3-TiO2 powders wear resistance

Preparation of semi-solid AlSi7Mg alloy slurry with big capability

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Rare Metals 2010年第6期29卷 642-645页

作者： LI Sha and MAO Weimin school of materials {2. and engineering,university of {2. and technology Beijing,Beijing 100083,china school of materials {2. and engineering University of Science and Technology Beijing Beijing China

Semi-solid AlSi7Mg alloy slurry was prepared by low superheat pouring and weak traveling-wave electromagnetic *** effects of pouring temperature and stirring power on the microstructure of AlSi7Mg alloy slurry were *** results show that the semi-solid AlSi7Mg alloy slurry of 5 kg can be *** new technology can save energy and make the pouring process *** the pouring temperature is decreased at a stirring power of 0.41 kW,the shape of primary α-Al grains gradually changes from dendritic-like to *** the alloy melt is poured at the temperature（630°C） with a certain superheat,the pouring process becomes easier,and the spherical microstructure of AlSi7Mg alloy slurry can be prepared by the weak traveling-wave electromagnetic *** the pouring temperature is 630°C,increasing the stirring power appropriately can result in better spherical primary α-Al grains,but if the stirring power is increased to a certain value（1.72.kW）,the shape of primary α-Al grains does not obviously improve when the stirring power is continually increased.

关键词： aluminum alloys metal forming semisolid slurry electromagnetic stirring microstructure

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

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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 {2.(taiyuan university of technology),Ministry of Education,taiyuan 03002.,china 2.ollege of {2. science and engineering,taiyuan university of technology,taiyuan 03002.,china 3College of Chemistry and Chemical engineering,taiyuan university of technology,taiyuan 03002.,china Key Laboratory of Interface science and engineering in Advanced {2. (taiyuan university of technology) Ministry of Education Taiyuan 030024 China College of materials science and {2. 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 P12. 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 P12. are critical to the formation of the *** coercivity value(2.1.91 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

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 Bingshe1,2.Key Laboratory of Interface science and engineering in Advanced {2. (taiyuan university of technology),Ministry of Education,Tai-yuan 03002.,china2.ollege of {2. science and engineering,taiyuan university of technology,taiyuan 03002.,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 2.m 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