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International Journal of Minerals,Metallurgy and Materials 2015年第9期22卷 956-965页

作者： Hai-tao Jiang qiang kang Xiao-qian Yan National Engineering Research Center for Advanced Rolling Technology University of Science and Technology Beijing China Railway Materials Technologies Company Limited

This article introduces an element diffusion behavior model for a titanium/steel explosive clad plate characterized by a typical curved interface during the heat-treatment process. A series of heat-treatment experiments were conducted in the temperature range from 750℃ to 950℃, and the effects of heat-treatment parameters on the microstructural evolution and diffusion behavior were investigated by optical microscopy, scanning electron microscopy, X-ray diffraction analysis, and electron-probe microanalysis. Carbon atoms within the steel matrix were observed to diffuse toward the titanium matrix and to aggregate at the bonding interface at 850℃ or lower; in contrast, when the temperature exceeded 850℃, the mutual diffusion of Ti and Fe occurred, along with the diffusion of C atoms, resulting in the for- marion of Ti-Fe intermetallics （Fe2Ti/FeTi）. The diffusion distances of C, Ti, and Fe atoms increased with increasing heating temperature and/or holding time. On the basis of this diffusion behavior, a novel diffusion model was proposed. This model considers the effects of various factors, including the curvature radius of the curved interface, the diffusion coefficient, the heating temperature, and the holding rime. The experimental results show good agreement with the calculated values. The proposed model could clearly provide a general prediction of the elements＇ diffusion at both straight and curved interfaces.

关键词： explosive bonding metal cladding diffusion models interfaces heat treatment

Effect of pre-tensioned rock bolts on stress redistribution around a roadway—insight from numerical modeling

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Journal of China University of Mining and Technology 2008年第4期18卷 509-515页

作者： GAO Fu-qiang kang Hong-pu Mining and Designing Branch Central Coal Research Institute Beijing 100013 China

The importance of the pre-tensioned force of rock bolts has been recognized by more and more researchers. To investi- gate the effect of pre-tensioned rock bolts on stress redistribution around roadways, a numerical analysis was carried out using FLAC3D and a special post-process methodology, using surfer, is proposed to process the numerical simulation results. The results indicate that pre-tensioned rock bolts have a significant effect on stress redistribution around a roadway. In the roof, pre-tensioned rock bolts greatly increase vertical stress; as a result, the strength of the rock mass increased significantly which results in a greater capacity of bearing a large horizontal stress. The horizontal stress decreases in the upper section of the roof, indicating that pre-tensioned rock bolts significantly reduce the coefficient and the size of the region concentration of horizontal stress. At the lat- eral side, pre-tensioned rock bolts greatly increase the horizontal stress; therefore, the rock mass strength significantly increases which results also in a greater capacity of bearing a large vertical stress. The greater the size of pre-tensioned force, the larger the region of stress redistribution around a roadway is affected and the higher the size of the stress on the roadway surface the more the rock mass strength increases.

关键词： pre-tensioned rock bolts stress redistribution numerical simulation

Rhodium（lll）/Amine Synergistically Catalyzed Enantioselective Alkylation of Aldehydes with α,β-Unsaturated 2-Acyl Imidazoles

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Chinese Journal of Chemistry 2016年第12期34卷 1225-1235页

作者： Jun Gong Kuan Li Saira Qurban qiang kang Key Laboratory of Coal to Ethylene Glycol and Its Related Technology Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences Fuzhou Fujian 350002 China Department of Chemistry Fuzhou University Fuzhou Fujian 350108 China

A synergistic catalysis combination of chiral-at-metal rhodium complex and amine catalyst was developed for enantioselective alkylation of aldehydes with α,β-unsaturated 2-acyl imidazoles. The corresponding adducts ... 详细信息

关键词： alkylation of aldehyde chiral-at-metal complex synergistic catalysis

Syntheses and Surface Properties of Polyacrylonitrile-based Copolymer Membranes Containing Sugar Moieties

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Chemical Research in Chinese Universities 2005年第3期21卷 355-359页

作者： HUANGXiao-jun WANLing-shu DAIZheng-wei KOURui-qiang XUZhi-kang InstituteofPolymerScience ZhejiangUniversityHangzhou310027P.R.China

To improve the hydrophilicity of polyacrylonitrile-based membranes, sugar moieties were incorporated into acrylonitrile-based copolymers via the radical copolymerization of α-allyl glucoside(AG) with acrylonitrile(AN) with 2,2′-azobis-iso-butyronitrile(AIBN) as the initiator in dimethyl sulphoxide(DMSO). It was found that the yield increased with the increase of the initiator concentration and reaction time, while it decreased with the increase of the monomer molar ratio of AG to AN. Raising the AG proportion in the monomer mixture resulted in the increase of the AG content in the copolymer. M_v of the copolymers decreased with increasing the AG monomer fraction in feed. The copolymers were fabricated into dense membranes and their surface properties were studied by means of the water contact angle measurement and platelet adhesion tests. It was found that the static water contact angle on the membrane decreased significantly from 70° to 33° with the increase of the AG content. The adhesive number of platelets on the membrane surface also decreased significantly with increasing AG content in the copolymers. These results demonstrate that the hydrophilicity and biocompatibility of the acrylonitrile-based copolymer membranes could be improved efficiently by the copolymerization of acrylonitrile with vinyl carbohydrates.

关键词： Polyacrylonitrile Sugar-containing copolymer Surface property Hydrophilicity Platelet adhesion

Texture and stretch formability of rolled Mg–Zn–RE(Y, Ce, and Gd) alloys at room temperature

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Rare Metals 2013年第5期32卷 441-447页

作者： Zheng-Xu Cai Hai-Tao Jiang Di Tang Zhao Ma qiang kang National Engineering Research Center of Advanced Rolling University of Science and Technology Beijing

To develop a new magnesium alloy with excellent formability at room temperature, the effect of Y, Ce, and Gd addition on texture and stretch formability of Mg-1.5Zn alloys was carried out. The result shows that Y, Ce, and Gd addition in Mg-1.5Zn alloys can effectively weaken and modify the basal plane texture, characterized by TD-split texture in which the position of basal is titled from normal direction （ND） toward transverse direction （TD）. When Mg-1.5Zn alloy with Gd addition appears low texture intensity and TD-split texture, where the position of basal poles is tilted by about 4-35° from ND toward to TD, the largest Erichsen value of 7.0 and the elongation rate reaches 29.1% in TD direction. However, Y and Ce addition in Mg-1.5Zn alloys promote a large number of second phase particles, which cancel the contribution of the unique basal texture to stretch formability and ductility.

关键词： Magnesium Texture Size effects Stretch formability Mechanical property Rare earth elements

Performance evaluation of the backprojection filtered (BPF) algorithm in circular fan-beam and cone-beam CT

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Nuclear Science and Techniques 2006年第2期17卷 113-117页

作者： LI Liang CHEN Zhi-qiang ZHANG Li kang Ke-Jun Department of Engineering Physics Tsinghua University Beijing 100084 China

In this article we introduce an exact backprojection filtered (BPF) type reconstruction algorithm for cone-beam scans based on Zou and Pan’s work. The algorithm can reconstruct images using only the projection data passing through the parallel PI-line segments in reduced scans. Computer simulations and practical experiments are carried out to evaluate this algorithm. The BPF algorithm has a higher computational efficiency than the famous FDK algorithm. The BPF algorithm is evaluated using the practical CT projection data on a 450 keV X-ray CT system with a flat-panel detector (FPD). From the practical experiments, we get the spatial resolution of this CT system. The algo- rithm could achieve the spatial resolution of 2.4 lp/mm and satisfies the practical applications in industrial CT inspec- tion.

关键词：反向发射滤波器算法 BPF Hilbert转换算法理论

Microstructure evolution and mechanical property of Mg-3Al alloys with addition of Ca and Gd during rolling and annealing process

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Journal of Magnesium and Alloys 2020年第3期8卷 769-779页

作者： Yun Zhang Haitao Jiang qiang kang Yujiao Wang Yonggang Yang Shiwei Tian Institute of Engineering Technology University of Science and Technology BeijingBeijing 100083China

The formability of magnesium alloys at ambient temperature can be enhanced by alloying additions such as Ca and RE elements,which is ascribed to the weakened basal *** produce magnesium alloy sheets with excellent comprehensive performance,the evolution of texture characterization during fabrication process and subsequent effect of texture on mechanical properties are vital controlling *** this investigation,three experimental Mg-3Al series alloys were hot rolled and annealed to sheets with 1 mm *** microstructure evolution during rolling and annealing process was ***,the influence of texture on tensile properties along different tensile directions was also *** results show that weakened basal texture and refined grains were achieved with the co-addition of Ca and RE ***,strengthening of mechanical properties wasn't *** hot rolling process,microstructure was refined,second phase particles broken,and basal texture was *** basal texture was weakened during annealing *** behavior influenced by formation of second phase was dominated to attenuate basal *** deformation behavior was controlled by basal slip and followed Schmid factor ***,the weakened basal texture and activation of non-basal slips during hot rolling process can contribute to diminish the anisotropy of tensile properties.

关键词： Magnesium alloys Microstructure evolution Texture Anisotropy

The effect of Y,Ce and Gd on texture,recrystallization and mechanical property of Mg-Zn alloys

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Journal of Magnesium and Alloys 2016年第3期4卷 188-196页

作者： Peng Liu Haitao Jiang Zhengxu Cai qiang kang Yun Zhang Institute of Engineering Technology University of Science and Technology BeijingBeijing 100083China

The effect of Gd,Ce and Y elements on texture,recrystallization and mechanical properties of Mg–1.5Zn alloys was *** results show that the addition of Gd,Ce and Y elements in Mg–1.5Zn alloy,which rolled at 450℃ and subsequently annealed at 350℃ for 1h,can effectively weaken and modify the basal texture,characterized by the splitting basal pole toward to transverse direction,leading to the yield and tensile strength,the highest along the rolling direction and the lowest along the transverse ***,the unique basal texture contributes to the significant improvement of elongation at room *** back scattering diffraction(EBSD)analysis indicated that the non-basal texture in Mg–1.5Zn–0.2RE alloys can be attributed to obstructive effect of static recrystallization and the non-basal orientation grains nucleation near pre-existing grain boundaries during ***,the Mg–1.5Zn–0.2Gd sheet exhibits much excellent plasticity with the elongation of 27%than Mg–1.5Zn–0.2Ce and Mg–1.5Zn–0.2Y alloys,resulting from the less and smaller second phase of MgZnGd.

关键词： Magnesium alloys Texture Recrystallization Rare earth element Microstructure

Rh/Lewis Acid Catalyzed Regio-, Diastereo- and Enantioselective Addition of 2-Acyl Imidazoles with Allenes

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Chinese Journal of Chemistry 2018年第1期36卷 20-24页

作者： Pranjal P. Bora Gui-Jun Sun Wei-Feng Zheng qiang kang Key Laboratory of Coal to Ethylene Glycol and Its Related Technology Fujian Institute of Research on the Structure of Matter Chinese Academy of Scienc- es 155 Yangqiao Road West Fuzhou Fujian 350002 China

A highly regio-, diastereo- and enantioselective addition of 2-acyl imidazoles or 2-acyl pyridines with allenes promoted by Rh/Lewis acid synergistically catalytic system is described. This atom economic approach leads to the formation of the branched allylic alkylated products including acyclic quaternary all-carbon stereogenic centres in good yields with good to excellent diastereo- and enantioselectivities. Kinetic studies reveal that the rate-determining step in this process is the oxidative addition of Rh（I） with C H bond.

关键词： rhodium allene enantioselective Lewis acid allylation

Kinetics and Mechanism of Interfacial Reaction in a SiC_f/Ti Composite

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Journal of Materials Science & Technology 2003年第5期19卷 407-410页

作者： Guoxing ZHANG, qiang kang, Nanlin SHI, Geping LI and Dong LIInstitute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China Inst. of Metal Res. Chinese Acad. of Sci. Shenyang 110016 China

In order to evaluate the interfacial reaction, a SiCf/Ti (TA1) composite was fabricated by a vacuum hot pressing method and then heat-treated in vacuum at 800℃ for up to 100 h. The elemental distributions of C, Si and Ti at the interfacial reaction zone were investigated. It was found that the reaction zone occurs during the fabrication process and continuously grows at high temperature because the Si and C atoms diffuse from SiC fibers to the matrix and Ti atoms diffuse in the opposite direction. The growth of the reaction zone is diffusion controlled and the mechanism of the reaction can be described by a reactive diffusion model of solid-state growth of an AmBn layer between two elementary substances A and B.

关键词： SiCf/Ti (TA1) composite Interfacial reaction Diffusion control