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Journal of Materials Science & Technology 2022年第15期110卷 136-151页

作者： C.yang M.q.Li y.G.Liu School of Materials Science and Engineering Northwestern Polytechnical UniversityXi’an 710072China

The face-centered cubic structure(fcc)and its deformation behaviors,as well as the distinctive role of fcc-Ti in nanocrystallization in TC17 subjected to high energy shot peening(heSP),were investigated by using comprehensive high-resolution transmission electron microscopy(HRTEM).The results showed that there was a stress-induced fcc-Ti in TC17 with a lattice constant of 0.420–0.433 nm and the B-type orientation relationship between the hcp-Ti and the fcc-Ti as[2-1-10]_(hcp)//[-110]_(fcc)and(0001)_(hcp)//(111)_(fcc),which was accomplished by the gliding of Shockley partial dislocations with Burgers vector of 1/3[01-10]on the basal *** deformation twinning dominated the subsequent deformation of fcc-Ti,producing two types of{111}twins with different *** them,the I-type twin with complete structure was generated by successive gliding of Shockley partial dislocations with the same Burgers vector of 1/6[11-2].In contrast,the cooperative slip of three Shockley partials,whose sum of Burgers vectors was equal to zero,produced the II-type twin with zero net macroscopic *** then,the emission of Shockley partial with the Burgers vector of 1/6[11-2]on every three(111)fccplanes resulted in the formation of a 9R *** to the dissociation effect of lamellar fcc-Ti and the superior deformation ability of fcc structure,the occurrence of fcc-Ti effectively promoted surface nanocrystallization of TC17.

关键词： TC17 Severe plastic deformation Stress-induced phase transformation Deformation twinning Nanocrystallization

STUDy ON The VARIATION MECHANISM OF CARBON CONTENT OF LIqUID IRON IN MELTING GASIFIER

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Acta Metallurgica Sinica(English Letters) 2003年第2期16卷 132-138页

作者： q.Lu L.F Sun y.Xu q.F.Chan hebei University of Technology Tangshan 063009ChinaHebei University of TechnologyTangshan 063009ChinaHebei University of TechnologyTangshan 063009ChinaHebei Institute of Vocation and TechnologvShiiiazhuang 050031China

This paper studied the changing principles of carbon content in direct reduction iron (DRI) and liquid iron in the COREX melting gasifier. Under the normal working conditions of experimental equipment, liquid nitrogen was poured into the melting gasifier from its tuyere to cool down quickly. And then seven cross sections were made to study the carburization reaction and its characteristics of the solid iron and the liquid iron, and also the reaction of carbon between the slag and the metal. According to the results, the influences of the thickness of the semi-coke layer and the temperature on the carbon content of liquid iron in the COREX melting gasifier were confirmed.

关键词： melting gasifier direct reduction iron (DRI) liquid iron carbon content

COORELATION ANALySIS OF SURFACE PRESSURE FLUCTUATIONS ON THREE EqUISPACED CyLINDERS

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Journal of Hydrodynamics 2001年第2期13卷 55-62页

作者： Dong, L.y. Xu, y.H. Huang, D.q. Inst. of Appl. Math. and Mech. Shanghai Univ. Shanghai 200072 China

The fluctuating pressures on the surface of three circular cylinders in equispaced arrangement were measured simultaneously in the medium subcritical regime (Re=3×104). The distributions of their rms values and circumferential correlation were obtained in the spacing range from 1.25 to 6.0. The spatial correlation of pressures of two pressure taps on two different cylinders at the same azimuth was investigated as well. Owing to different flow patterns in various arrangements and spacing, these correlation curves of pressure show different distributions. The lift fluctuation can be estimated qualitatively from the circumferential coefficient curve with the knowledge of the rms pressure distribution. Some critical spacing for each arrangement were found that the flow regimes and the corresponding pressure correlation take a sudden change. Flow interference between cylinders in each arrangement was also discussed with various flow regimes.

关键词： Cylinders (shapes) Experiments Flow interactions Flow patterns Pressure distribution Pressure measurement

Role of extrusion rate on the microstructure and tensile properties evolution of ultrahigh-strength low-alloy Mg-1.0Al-1.0Ca-0.4Mn(wt.%)alloy

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Journal of Magnesium and Alloys 2023年第2期11卷 553-561页

作者： X.q.Liu X.G.qiao R.S.Pei y.q.Chi L.yuan M.y.Zheng School of Material Science and Engineering Harbin Institute of TechnologyHarbin 150001China Institut fur Metallkunde und Meterialphysik RWTH Aachen UniversityAachen D-52056Germany

Mg-1.0Al-1.0Ca-0.4Mn(AXM1104, wt.%) low alloy was extruded at 200 ℃ with an extrusion ratio of 25 and different ram speeds from 1.0 to 7.0 mm/s. The influence of extrusion rate on microstructure and mechanical properties of the AXM1104 alloy was systematically studied. With the increasing of extrusion rate, the mean dynamically recrystallized(DRXed) grain size of the low alloy and average particles diameter of precipitate second phases were increased, while the degree of grain boundary segregation and the intensity of the basal fiber texture were decreased. With the rising of extrusion rate from 1.0 to 7.0 mm/s, the tensile yield strength(TyS) of the as-extruded AXM1104 alloy was decreased from 445 MPa to 249 MPa, while the elongation to failure(EL) was increased from 5.0% to 17.6%. The TyS, ultimate tensile strength(UTS) and EL of the AXM1104 alloy extruded at the ram speed of 1.5 mm/s was 412 MPa, 419 MPa and 12.0%, respectively,exhibiting comprehensive tensile mechanical properties with ultra-high strength and excellent plasticity. The ultra-high TyS of 412 MPa was mainly due to the strengthening from ultra-fine DRXed grains with segregation of solute atoms at grain boundaries. The strain hardening rate is increase slightly with increasing extrusion speed, which may be ascribed to the increasing mean DRXed grain size with rising extrusion speed. The higher strain hardening rate contributes to the higher EL of these AXM1104 samples extruded at higher ram speed.

关键词： Mg-Al-Ca-Mn alloy Ultrafine grain Extrusion rate Grain boundary segregation Microstructure Ultrahigh strength

A new type of oceanic crust and its dynamical significance

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Chinese Science Bulletin 1997年第1期42卷 54-57页

作者： Zhang, q Zhou, DJ Chen, y Institute of Geology Chinese Academy of Sciences Beijing China

The oceanic lithosphere is composed of oceanic crust and upper mantle. It is widely accepted that the Troodos ophiolitic section represents the oceanic crust section, which consists of ultramafic cumulates in the bottom, and grades upward into cumulative gabbros, isotropic gabbro, sheeted dikes and pillow lavas, covered by abyssal sediments. According to the marine geophysical investigation, the oceanic crust can be divided into three layers which from top to bot-

关键词： oceanic crust ophiolite oceanic ridge dynamics.

Dynamic Coordination of Uncalibrated Hand/Eye Robotic System Based on Neural Network

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Journal of Systems Engineering and Electronics 2001年第3期12卷 45-50页

作者： Su, J. Pan, q. Xi, y. Institute of Automation Shanghai Jiaotong University Shanghai 200030 China

A nonlinear visual mapping model is presented to replace the image Jacobian relation for uncalibrated hand/eye coordination. A new visual tracking controller based on artificial neural network is designed. Simulation results show that this method can drive the static tracking error to zero quickly and keep good robustness and adaptability at the same time. In addition, the algorithm is very easy to be implemented with low computational complexity.

关键词： Adaptive algorithms Computational complexity Computer simulation Coordinate measuring machines Error detection Mathematical models Neural networks Robotic arms Robustness (control systems) Stereo vision

EFFECT OF NANOCRySTALLINE AND TWIN BOUNDARIES ON CORROSION BEHAVIOR OF 316L STAINLESS STEEL USING SMAT

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Acta Metallurgica Sinica(English Letters) 2006年第3期19卷 183-189页

作者： A.q. Lü y. Zhang y. Li G. Liu q.H. Zang C.M. Liu School of Materials and Metallurgy Northeastern University Shenyang 110004 China Jiuquan Iron ＆ Steel （Group） Go. Ltd Jiayuguan 735100 China State Key Laboratory for Corrosion and Protection of Metals Institute of Metal Research The Chinese Academy of Sciences Shenyang 110015 China Shenyang National Laboratory for Materials Science Institute of Metal Research The Chinese Academy of Science Shenyang 110016 China

By means of surface mechanical attrition treatment （ SMAT）, the groin size with a diameter of aboat 60hm formed at about 20μm depth and numerous mechanical twins at about 50μm depth from the treated surface were synthesized in 316L stainless steel because of the different distributions of strain and strain rate along depth orientation. For instance the maximum strain rate reached 10^3-10^4s^-1 on the top surface. The relationship between the microsturcture and the corrosion property was studied in 0.05M H2SO4＋ 0.25M Na2SO4 aqueous solution, and the results show an extreme improvement of corrosion resistance owing to the appearance of twin boundaries and the obvious reduction in corrosion resistance attributed to the presence of nanocrystaline boundaries.

关键词： surface mechanical attrition treatment 316L stainless steel corrosion property twin boundary nanocrystaline boundary

On Pattern Avoiding Flattened Set Partitions

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Acta Mathematica Sinica,English Series 2015年第12期31卷 1923-1928页

作者： Thomas y.H.LIU Andy q.ZHANG Department of Foundation Courses Southwest Jiaotong University Center for Combinatorics LPMC-TJKLCNankai University

Let Π = B1/B2/… /Bk be any set partition of[n]= {1,2,...,n} satisfying that entries are increasing in each block and blocks are arranged in increasing order of their first *** Callan defined the flattened Π to be the permutation of[n]obtained by erasing the divers between its blocks,and Callan also enumerated the number of set partitions of[n]whose flattening avoids a single3-letter *** posed the question of counting set partitions of[n]whose flattening avoids a pattern of length *** this paper,we present the number of set partitions of[n]whose flattening avoids one of the patterns：1234,1243,1324,1342,1423,1432,3142 and 4132.

关键词： Set partition pattern avoidance flattened partition

Corrosion behavior of 13Cr stainless steel under stress and crevice in high pressure CO_(2)/O_(2)environment

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Journal of Materials Science & Technology 2021年第29期88卷 79-89页

作者： G.y.Zhu y.y.Li B.S.Hou q.H.Zhang G.A.Zhang Key Laboratory of Material Chemistry for Energy Conversion and Storage Ministry of EducationHubei Key Laboratory of Materials Chemistry and Service FailureSchool of Chemistry and Chemical EngineeringHuazhong University of Science and TechnologyWuhan430074China

In this work,through the self-developed setup for in situ electrochemical tests,the corrosion behavior of 13 Cr stainless steel under the combined effect of stress and crevice in high pressure CO_(2)/O_(2)environment was *** results show that 13 Cr stainless steel presents a self-passivation *** the action of stress,the anodic dissolution process of steel inside crevice is *** is a galvanic effect between the stressed steel inside crevice and the unstressed steel outside *** applied stress reduces the induction stage of crevice corrosion and induces a larger galvanic current,i.e.,the applied stress promotes the development of crevice ***,adding 0.1 MPa O_(2)is conducive to forming a more stable passive film but causes a greater galvanic effect.

关键词： Stainless steel Crevice corrosion Stress corrosion Galvanic effect

Magnetohydrodynamic flows tuning in a conduit with multiple channels under a magnetic field applied perpendicular to the plane of flow

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Journal of Hydrodynamics 2017年第2期29卷 332-343页

作者： y.Luo C.N.Kim M.q.Zhu Department of Mechanical Engineering Graduate SchoolKyung Hee UniversityYong-inKorea Department of Mechanical Engineering College of EngineeringKyung Hee UniversityYong-inKorea

In this study, three-dimensional liquid-metal magnetohydrodynamic flows in a conduit with multiple channels under a uniform magnetic field are numerically investigated. The geometry of the conduit is of a four-parallel-channels system including one inflow channel and three outflow channels. The liquid-metal flows into the inflow channel, then turns through 180° in the transi- tion segment, finally flows into three different outflow channels. This kind of channel system can induce counter flow and co-flow, which is rarely investigated before though the conceptual designs of duct flow in the blanket have suggested this type of flow. A structured grid system is chosen after a series of mesh independence tests in the present study. The axial velocity in the side layer near the first partitioning wall, located between the inflow channel and the first outflow channel, is the highest with the lowest electric potential formed therein. The pressure almost linearly decreases in the main flow direction, except in the transition segment. Moreover, the pressure gradient in the first outflow channel is the largest among the three outflow channels. The interdependency of the current, fluid velocity, pressure, electric potential is examined in order to describe the electromagnetic characteristics of the liquid-metal flows.

关键词： Liquid-metal magnetohydrodynamics multiple channels