检索结果-南通市图书馆

Bionic Design and Finite Element Analysis of Elbow in Ice Transportation Cooling System

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic engineering 2010年第3期7卷 301-306页

作者： Dejun Miao~(1,2., Xiuhua Sui~3, Linjing Xiao~3 1. Key Laboratory of Mine Hazard Prevention and Control (Ministry of Education, china), shandong {2. of science and Technology, Qingdao 2.6510, P. R. china 2. school of Architecture, Tsinghua {2., Beijing 100084, P. R. china 3. College of Mechanical and Electronic engineering, shandong {2. of science and Technology, Qingdao 2.6510, P. R. china [a] Key Laboratory of Mine Hazard Prevention Control (Ministry of Education China) Shandong University of Science Technology Qingdao 266510 P. R. China [b] School of Architecture Tsinghua University Beijing 100084 P. R. China [c] College of Mechanical Electronic engineering Shandong University of Science Technology Qingdao 266510 P. R. China

With the increase in mining depth, mine heat harm has appeared to be more prominent. The mine heat harm could be resolvedor reduced by ice refrigeration. Thus, ice transportation through pipeline becomes a critical problem; typically flowresistance occurs in the elbow. In the present study, according to the analysis of the surface morphology of fish scale, abiomimetic functional surface structure for the interior wall of elbow is designed. Based on the theory of liquid-solid two phaseflow, a CFD numerical simulation of ice-water mixture flowing through the elbow is carried out using finite element *** experiments of pressure drop and flow resistance for both bionic and common elbows are conducted to test theeffect of the bionic elbow on flow resistance reduction. It is found that with the increase in the ice mass fraction in the ice-watermixture, the effect of bionic elbow on resistance reduction becomes more obvious.

关键词： bionic elbow two phase flow ice transportation flow resistance reduction pressure loss

Effect of surface nanocrystallization on the corrosion behavior of Zircaloy-4

在线全文

学校读者我要写书评

暂无评论

science china(Technological sciences) 2009年第8期52卷 2227-2231页

作者： ZHU YuTao1,2.& ZHANG XiYan1,2.3 1 College of materials science and {2., Chongqing university, Chongqing 400045, china 2.National {2. Research Center for Magnesium Alloys, Chongqing university, Chongqing 400044, china 3 school of Physical science and {2. Technology, Guangxi university, Nanning 530004, china 1. College of materials science and {2. Chongqing University Chongqing 400045 China 2. National engineering Research Center for Magnesium Alloys Chongqing University Chongqing 400044 China 3. school of Physical science and {2. Technology Guangxi University Nanning 530004 China

The contrastive corrosion experiments between surface nanocrystallined Zircaloy-4 and coarse-grained Zircaloy-4 under the condition of 673 K/10.3 MPa in pure water are carried out, and the microstructure of oxide films has been studied. The results indicate that the growth rate of oxide films formed on the nanocrystalline Zircaloy-4 is lower than that of oxide films formed on the coarse-grained Zircaloy-4. Simultaneously, the oxide/metal interface of the former is more regular and glossy than that of the latter. For nanocrystalline Zircaloy-4, the low oxygen diffusion rate through the oxide/metal interface can hinder the reaction of oxygen ion with metal ion. Furthermore, more tetragonal ZrO2.are observed in the oxide films, which can delay the martensite phase transition from tetragonal to monoclinic phase in oxide films.

关键词： nanocrystalline Zircaloy oxide film microstructure

Development and Application of High Performance X80 Line Pipe for the 2.(nd) West-East Gas Pipeline

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2011年第S1期18卷 39-48页

作者： LI He-lin 1 , HUO Chun-yong 1 , JI Ling-kang 1, 2., LI Yang 1, 3 (1. CNPC Tubular Goods Research Institute, Xi’an 710065, china 2. . school of Material {2. and engineering, Xi’an Jiaotong university, Xi’an 710049, china 3. school of Material {2. and engineering, university of {2. and Technology Beijing, Beijing 100083, china) CNPC Tubular Goods Res Inst Xian 710065 Peoples R China Xi An Jiao Tong Univ Sch Mat Sci & Engn Xian 710049 Peoples R China Univ Sci & Technol Beijing Sch Mat Sci & Engn Beijing 100083 Peoples R China

It is the development tendency of gas pipeline to improve strength of line pipe and transmission pressure, which is an important symbol of the progress of gas pipeline technology. The 2.d West-East Gas Pipeline (the 2.nd WEGP) is the largest-scale X80 high pressure gas pipeline project in the world. Through the joint development project by Pipeline Company, research institute, and steel company, a series of achievements of technology have been obtained, which makes it possible to apply pressure of 12.MPa and X80 LSAW and HSAW pipe for the 2.nd WEGP. Specifications of X80 steel and pipe have been issued based on API 5L. High performance X80 steel and pipe have been developed and meets the Specification. General design conception of applying HSAW pipe and LSAW pipe on gas transmission trunk line with large diameter and high pressure has been established. Failure control of the 2.nd WEGP has been carried out to avoid failure and reduce the lost which based on analysis of pipeline failure mode. In this paper, research and development of high performance X80 welded pipe, establishment of technical route of joint application of HSAW and LSAW steel pipe and key technology of failure control are emphatically discussed.

关键词： 2.nd WEGP acicular ferrite failure control arrest toughness strain-based design

Application of mesoscale modeling optimization to development of advanced materials

在线全文

学校读者我要写书评

暂无评论

Progress in Natural science:materials International 2004年第8期14卷 8-15页

作者： SONG Xiaoyan(school of materials {2. and engineering, Beijing university of Technology, Beijing 10002., china) Beijing Univ Technol Sch Mat Sci & Engn Beijing 100022 Peoples R China

The rapid development of computer modeling in recent years offers opportunities for materials preparation in a more economic and efficient way. In the present paper, a practicable route for research and development of advanced materials by applying the visual and quantitative modeling technique on the mesoscale is introduced. A 3D simulation model is developed to describe the microstructure evolution during the whole process of deformation, recrystallization and grain growth in a material containing particles. In the light of simulation optimization, the long-term stabilized fine grain structures ideal for high-temperature applications are designed and produced. In addition, the feasibility, reliability and prospects of material development based on mesoscale modeling are discussed.

关键词： mesoscale computer simulation Monte Carlo technique deformation recrystallization grain growth.

Effect of Fe metal on the growth of silicon oxide nanowires

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and materials 2009年第3期16卷 317-321页

作者： Wei-long Liu1), Shu-huei Hsieh1), Ching He Chen2., and Wen-jauh Chen3) 1) Department of materials science and {2., Formosa university, Yunlin 632. china Taipei 2. Department of materials {2., Pingtung university of science and Technology, Pingtung 912. china Taipei 3) Graduate school of materials science, Yunlin university of science and Technology, Yunlin 632. china Taipei [a]Department of materials science and {2. Formosa University Yunlin 632 China Taipei [b]Department of Materials Engineering Pingtung University of Science and Technology Pingtung 912 China Taipei [c]Graduate School of Materials Science Yunlin University of Science and Technology Yunlin 632 China Taipei

Silicon oxide (SiOx) nanowires are generally grown on Si substrate under the catalysis of Au in N2.atmosphere at elevated temperatures. Because the price of Au metal is quite high, Fe metal is then used to replace a part of Au for catalyzing the growth of SiOx nanowires. The results show that the Fe film can be used as the diffusion barrier of Au. SiOx nanowires are grown on Au/Fe/Si substrate at 1030°C. Under the catalysis of Fe/Au, the efficiency for the growth of SiOx nanowires is promoted.

关键词： silicon oxide nanowires Au catalyst Fe substitution Si substrate

Sol-gel Preparation and Infrared Radiation Property of Boron-substituted Cordierite Glass-ceramics

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of materials science & Technology 2010年第5期26卷 445-448页

作者： Shuming Wang and Fenghua Kuang school of materials {2. and engineering,university of {2. & Technology Beijing,Beijing 100083,china [a] school of materials {2. and engineering university of science & Technology Beijing Beijing 100083 china

Boron for aluminum substitution in the cordierite structure has been examined by sol-gel preparation of different samples along the compositional junction Mg2.l4-xBxSi5O18 with x=0,0.5,1,*** increasing the x value from 0 to 1.5 the crystallization behavior changed *** amount B2.3 doping can promote the sintering of amorphous cordierite gel,effectively restrain the precipitation of μ-cordierite and enhance the crystallization of α-*** substitution of B3＋ for Al3＋ in cordierite crystal structure can effectively improve the near-infrared spectral emissivity of this cordierite based glass-ceramics.

关键词： Sol-gel Glass-ceramics Infrared radiation B3+ substitution Solid solution

Analysis for twinning and slip in face-centered cubic crystals under axisymmetric co-deformation

在线全文

学校读者我要写书评

暂无评论

science china(Technological sciences) 2006年第5期49卷 521-536页

作者： CHEN Zhiyong1,2. CAI Hongnian1, ZHANG Xinming2. WANG Fuchi1 & TAN Chengwen1,3 1. school of Material science and {2., Beijing Institute of Technology, Beijing 100081, china 2. school of Material science and {2., Central South university, Changsha 410083, china 3. school of Material science and {2., Beijing university of Aeronautics and Astronautics, Beijing 100083, china 1. school of Material science and {2. Beijing Institute of Technology Beijing 100081 China 2. school of Material science and {2. Central South University Changsha 410083 China 3. school of Material science and {2. Beijing University of Aeronautics and Astronautics Beijing 100083 China

The maximum work principle of Bishop-Hill was developed to analyze the axisymmetric co-deformation in face-centered cubic crystals (f.c.c.) for twinning on {111} 112.and slip on {111} 110 systems. The influence of ξ , the ratio of critical re- solved shear stress for twinning to slip, on the yield stress states and corresponding active slip or/and twinning systems for orientations in the standard stereographic triangle of cubic crystal was investigated systematically. The Taylor factors and the anisotropy of yield strength for three important orientations [100], [110] and [111] in orientation space were analyzed. It is found that the yield strength asymmetry for the case of axisymmetric de- formation of tension and compression can be explained based on the microscopic theory of crystal plasticity. The concept of orientation factor for twinning ability was proposed and the deformation mechanism map in the orientation space was established for the case of axisymmetric deformation. The deformation texture formation and development of f.c.c. crystals with low stacking fault energy for axisymmetric tension can be explained qualita- tively on the basis of analyzed results.

关键词： twinning slip face-centered cubic crystals axisymmetric co-deformation Bishop-Hill maximum work principle yield strength anisotropy

Influences of Heat Treatments on Crystallization in SiO_2.Al_2._3-MgO-K_2.-F Glass-ceramics

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan university of Technology(materials {2.) 2011年第3期26卷 403-406页

作者：田清波 school of materials {2. and engineering Shandong Jianzhu University

Five kinds of heating treatment processing were chosen according to the experiment result of differential scanning calorimeter to prepare SiO2.Al2.3-MgO-K2.-F glass ceramics *** effects of heat treatment processing on the crystallization of these samples were explored by X-ray diffraction and scanning electron microscopy *** results indicate that phase separations can occur in the bulk regions of the glass sample when holding at 670 ℃ for 3 *** phase separation can accelerate the precipitation of the crystallization phase： when the temperature directly rises to 950 ℃ after the phase separation,there are mainly interlocked plate-shapes mica phases;If holding at 860 ℃ for 3 h first after the phase separation,the star-shape cordierite phases form;Thereby,elevating temperature to 950 ℃ and holding for 1 h will bring plate-shapes mica phases growing at inter-phases of the star-shape cordierite and finally the homogeneously distributed mica- cordierite composites ***,if heating at 950 ℃ directly without holding at 670 ℃,there is a small quantity of phase separation appearing at 670 ℃ and a little crystallization phases precipitating at last.

关键词： thermal decomposition mechanism kinetics Siderite

Dislocation Densites of Deformed Steel Sheets Based on Positron Annihilation

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and materials 1998年第1期12卷 47-50页

作者： Yonglin Kang Xianjin Wang (materials science and {2. school, university of science and Technology Beijing, Beijing 100083, china) materials science and {2. school University of Science and Technology Beijing Beijing 100083 China

The variation regularity of dislocation densites of some deformed steel sheets under three kinds of strainpaths as uniaxial tension, plane strain and equal biaxial stretching was investigated by means of positron lifetimespectrum and Doppler-broadening techniques. The results show that the increasing rate of dislocation densites isrelated to the plastic strain path. A relationship between the increasing rate of micro-defects, macro-instability andforming limits during the process of steel sheet forming was got based on analyzing the mechanism of dislocationdensity increasing under different stress-strain condihons.

关键词： positron annihilation dislocation steel sheet strain path