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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,{2. university of Science and technology,{2. 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

Crystallization in Zr_(60)Al_(15)Ni_(2.) 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,{2. university of Science and technology,{2. 03002.,China 1. school of Materials Science and engineering Taiyuan University of Science and Technology Taiyuan 030024 China

The microstructure evolution of Zr60Al15Ni2. 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

STUDY ON THE coal-ROCK INTERFACE RECOGNITION METHOD BASED ON MULTI-SENSOR DATA FUSION TECHNIQUE

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Chinese Journal of Mechanical engineering 2003年第3期16卷 321-324页

作者： Ren FangYang ZhaojianXiong ShiboResearch Institute of Mechano-Electronic engineering,taiyuan {2. of technology,taiyuan 03002., China Research Institute of Mechano-Electronic engineering Taiyuan University of Technology Taiyuan 030024 China

The coal-rock interface recognition method based on multi-sensor data fusiontechnique is put forward because of the localization of single type sensor recognition method. Themeasuring theory based on multi-sensor data fusion technique is analyzed, and hereby the testplatform of recognition system is manufactured. The advantage of data fusion with the fuzzy neuralnetwork (FNN) technique has been probed. The two-level FNN is constructed and data fusion is carriedout. The experiments show that in various conditions the method can always acquire a much higherrecognition rate than normal ones.

关键词： coal-rock interface recognition (CIR) Data fusion (DF) Multi-sensor

Effect of Preparation Methods on Mechanical Properties of PVA/HA Composite Hydrogel

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Journal of Bionic engineering 2010年第3期7卷 235-243页

作者： Dekun Zhang~1, Junjie Duan~1, Dagang Wang~2. Shirong Ge~2.1. school of Materials Science and engineering, China {2. of mining and technology Xuzhou 2.1116, P. R. China 2. school of Mechanical and Electrical engineering, China {2. of mining and technology, Xuzhou 2.1116, P. R. China [a] school of Materials Science engineering China University of Mining technology Xuzhou 221116 P. R. China [b] School of Mechanical Electrical engineering China University of Mining technology Xuzhou 221116 P. R. China

Poly(vinyl alcohol) (PVA)/hydroxyapatite (HA) composite hydrogel specimens were prepared with 15% PVA and 1%,2., 3%, 4% and 5% HA by repeated freezing-thawing. The tests of static and dynamic mechanical properties were carried out todiscuss the influence of different contents of HA and freezing-thawing cycles on the mechanical properties of PVA/HA compositehydrogel. The results of static mechanical tests showed that the PVA/HA composite hydrogel with 3% HA and ninefreezing-thawing cycles had excellent stress relaxation properties, higher relaxation ratio, lower stress equilibrium value andpresented better properties of creep and recovery. The results of dynamic mechanical test showed that the PVA/HA compositehydrogel with nine freezing-thawing cycles had higher storage modulus and loss modulus, so was the PVA/HA compositehydrogel with 3% HA.

关键词： composite hydrogel HA contents freezing-thawing cycles static properties dynamic properties

Allocation of power generating and shipping of Hanjiang upstream cascade

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Progress in Natural Science:Materials International 2005年第8期15卷 733-741页

作者： LIU Junping1* and CHANG Mingqi 2.3(1. school of Civil engineering and Architecture, Zhejiang {2. of technology, Hangzhou 310014, China 2. Institute of Water Resources & Hydroelectric engineering, Xi'an {2. of technology, Xi'an 710048, China 3. Shanxi Institute of Water Resources, taiyuan 030001, China) school of Civil engineering and Architecture Zhejiang University of Technology Hangzhou 310014 China Institute of Water Resources and Hydroelectric engineering Xi'an University of Technology Xi'an 710048 China Shanxi Institute of Water Resources Taiyuan 030001 China

The optimal model and simulating model of the Hanjiang cascade reservoirs operation with one day as its calculating period are established to coordinate the contradictions between power generating and shipping. The optimal model is solved by progressive optimality algorithm method adopting the theory of large system decomposing and coordinating. By analyzing the water allocation results obtained from six schemes, which are two cascades, four cascades and seven cascades joint operation considering shipping or not, the contradiction degree between power generating and shipping is investigated and some joint operation schemes are proposed.

关键词： cascade power generating contradiction shipping optimal operation.

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 Science and engineering, Shanghai Jiao Tong {2., Shanghai 2.0030, China 2. school of Materials Science and engineering, taiyuan {2. of Science and technology, taiyuan 03002., China 3. school of Environmental Science and engineering, Shanghai Jiao Tong {2., 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 Science 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.

Synthesis of SWNTs from Charcoal by Arc-discharging

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Journal of Wuhan university of technology(Materials Science) 2010年第2期25卷 194-196页

作者：范玮卫吕永康 Key Laboratory of coal Science and technology of Ministry of Education and Shanxi Province Taiyuan University of Technology

With charcoal as carbon source and FeS （2.wt%） as catalyst, single-wall carbon nanotubes （SWNTs） were successfully produced by dc arc-discharge method. The analysis by scanning electron microscopy, high-resolution transmission electron microscopy and Raman spectroscopy clearly demonstrated that the SWNTs developed from charcoal achieved a high purity with diameter about 1.2.nm, and FTIR measurement showed the inner structural transformation of carbon source, in which functional groups and grapheme sheets were decomposed and then ordered into nanotubes. By this easy-get and relatively low cost material, the experimenal results clearly indicate that charcoal has the opportunity of reducing the cost of SWNTs production.

关键词： charcoal single-wall carbon nanotubes catalyst

Simultaneous Removal of COS and H_2. at Low Temperatures over Nanoparticle a-FeOOH Based Catalysts

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Journal of Natural Gas Chemistry 2003年第1期12卷 37-42页

作者： Zhihua Gao, Chunhu Li, Kechang XieState Key Lab of C1 Chemistry and technology, Institute of coal Chemical {2., taiyuan university of technology,taiyuan 03002., China Stt. Key Lab of C1 Chem./technology Inst. of Coal Chemical Engineering Taiyuan University of Technology Taiyuan 030024 China

Catalysts using α-FeOOH nanoparticles as the active ingredient were testedby a microreactor-chromatography assessing apparatus at atmospheric pressure between 2. and 60 ℃with a gas hourly space velocity of 10,000 h^(-1), while the removal performance of H_2. withcatalysts was investigated using the thermal gravimetric method. The results show that the catalystsare highly active for COS hydrolysis at low temperatures (≤60 ℃) and high gas hourly spacevelocity, and the highest activity can reach 100%. The catalyst is particularly stable for 12.h, andno deactivation is observed. Nanoparticle α-FeOOH prepared using hydrated iron sulfate showshigher COS hydrolysis activity, and the optimum calcination temperature for the catalyst is 2.0 ℃.In addition, the catalysts can remove COS and H_2. simultaneously, and 60 ℃ is favorable for theremoval of H_2.. The compensation effect exists in nanoparticle-based catalysts.

关键词： nanoparticle α-FeOOH COS hydrolysis removal of H_2. compensationeffect

Direct Synthesis of Acetic Acid from CH_(4)and CO_(2.in the Presence of O_(2.over a V_(2.O_(5)-PdCl_(2./Al_(2.O_(3)Catalyst

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Journal of Natural Gas Chemistry 2004年第2期13卷 113-115页

作者： Wei Huang, Cuihong Zhang, Lihua Yin, Kechang XieKey Laboratory of coal Science and technology ({2. university of technology), Ministry of Education and Shanxi Province Institute of coal Chemistry and engineering, taiyuan university of technology,No. 79 Yingze West Street, taiyuan 03002., China Key Laboratory of coal Science and technology ({2. university of technology) Ministry of Education and Shanxi Province Institute of coal Chemistry and engineering Taiyuan University of Technology No. 79 Yingze West Street Taiyuan 030024 China

The possibility of synthesizing acetic acid from CH4 and CO2.in the presence of O2.over a V2.5-PdCl2.Al2.3 catalyst has been explored. The result shows that it is feasible in catalyzing a direct conversion of CH4, CO2.and O2.to acetic acid. It is concluded that both CO2.and O2.are involved in the formation of acetic acid.

关键词： methane carbon dioxide oxygen acetic acid heterogeneous catalytic system