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EFFECT OF UNEQUAL DEFORMATION IN DEVELOPMENT OF ADVANCED PLASTIC PROCESSING TECHNOLOGIES

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Chinese Journal of Mechanical engineering 2002年第1期15卷 79-82页

作者： Yang He Xian Feijun college of materials science and engineering，Northwestern Polytechnical university，Xi’an 710072，china college of materials science and engineering Northwestern Polytechnical University Xi'an 710072

An effect of unequal deformation in development of advanced plasticprocessing technologies is researched by studying an in-plane bending process of strip metal underunequal compressing. The research results show the following: If appropriately controlled, unequalplastic deformation can play an important role not only in the improvement of quality of partsobtained by plastic processing technologies, but also in the development of new processes foradvanced plastic working technologies. A coordinated growth of unequal plastic deformation candevelop the deformation potentiality of material to the fall. The degree of unequal plasticdeformation can be used as bases for optimization design of processes and dies of plastic forming.

关键词： Unequal plastic deformation In-plane bending Net shape process Computer simulation Advanced manufacturing technology

Preparation of polystyrene/silica nanocomposites by radical copolymerization of styrene with silica macromonomer

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science china Chemistry 2007年第3期50卷 385-391页

作者： OU BaoLi1,2 & LI DuXin2 1 college of Chemistry and Chemical engineering, hunan university of science and Technology, Xiangtan 411201, china 2 State Key Laboratory of Powder Metallurgy, Central South university, changsha 410083, china 1. college of Chemistry and Chemical engineering Hunan University of Science and Technology Xiangtan 411201 China 2. State Key Laboratory of Powder Metallurgy Central South University Changsha 410083 China

A two-stage process has been developed to generate the silica-based macromonomer through surface-modification of silica with polymerizable vinyl groups. The silica surfaces were treated with excess 2,4-toluene diisocynate (TDI), after which the residual isocyanate groups were converted into polymerizable vinyl groups by reaction with hydroxypropylacrylate (HPA). Thus, polystyrene/silica nanocomposites were prepared by conventional radical copolymerization of styrene with silica macromonomer. The main effecting factors, such as ratios of styrene to the macromonomer, together with polymerization time on the copolymerization were studied in detail. FTIR, DSC and TGA were utilized to characterize the nanocomposites. Experimental results revealed that the silica nanoparticles act as cross-linking points in the polystytene/silica nanocomposites, and the glass transition temperatures of the nanocomposites are higher than that of the corresponding pure polystyrene. The glass transition temperatures of nanocomposites increased with the increasing of silica contents, which were further ascertained by DSC.

关键词： silica nanoparticles surface modification styrene radical copolymerization nanocomposites

Electronic Structures and Properties of V, Nb and Ta Metals

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Journal of Central South university 2000年第1期12卷 7-11页

作者： HE Yu,XIE You qing (Department of materials science and engineering, Central South university of Technology, changsha 410083, china) 1. Department of materials science and engineering Central South University of Technology 410083 Changsha China

The electronic structures of pure V, Nb and Ta metals with bcc structure were determined by one atom (OA) theory. According to the electronic structures of these metals, their potential curves, cohesive energies, lattice parameters, elasticity and the dependence of linear thermal expansion coefficients on temperature were calculated. The electronic structures and characteristic properties of these metals with fcc and hcp structures and liquid states were studied.

关键词： electronic structure potential curve cohesive energy lattice parameter elasticity linear thermal expansion efficient V Nb Ta

Induced electric fields and plasmonic interactions between a metallic nanotube and a thin metallic film

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science china(Physics,Mechanics & Astronomy) 2010年第1期53卷 38-43页

作者： LI HongJian 1,2 , FU ShaoLi 1 , XIE SuXia 1,2 , XU HaiQing 1 , ZHOU Xin 1,2 & WU JinJun 1 1 college of Physics science and Technology, Central South university, changsha 410083, china 2 college of materials science and engineering, Central South university, changsha 410083, china 1. college of Physics science and Technology Central South University Changsha 410083 China2. College of Materials Science and Engineering Central South University Changsha 410083 China

We have numerically simulated the induced electric fields and the plasmonic interactions of a metallic nanotube near a thin metallic film. Our study shows that the energies and intensities of the plasmon resonances depend strongly on the aspect ratio (the ratio of the inner to outer radius) of the nanotube as well as the separation between the center of the nanotube and the upper surface of the metallic film and the thickness of the film. The enhancement of the induced electric field of this system reaches as high as 10 4 orders of magnitude and its field distribution is characterized by waveguide-mode resonance. The report proposes that these phenomena can be applied to designing surface enhanced spectroscopies such as surface enhanced Raman spectroscopy for efficient chemical and biological sensing.

关键词： metallic nanotube virtual state plasmons extinction spectrum

Numerical Simulation of Solidification Microstructure and Effects of Phase-field Parameters on Grain Growth Morphologies

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Journal of materials science & Technology 2005年第6期21卷 921-924页

作者： Jingfeng LIU+, Ruixiang LIU and Liliang CHEN Research Studio of Solidification Simulation, college of materials science and engineering, Huazhong university of science and Technology, Wuhan 430074, china Research Studio of Solidification Simulation College of Materials Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China

By a simple phase field model, a series of numerical simulations of solidification microstructure was performed to show a rich variety of dendritic patterns. At the same time, the relation between the morphology of grain growth and some parameters including the strength of anisotropy, dimensionless latent heat and the size of initial solid zone was studied. It is for the first time that patterns of grain growth were associated with the size of initial solid zone, which is an interesting issue. The possible reason for this may be that variation in the size of initial solid zone may bring about fluctuation of the interface energy, making the interface unstable.

关键词： Phase-field model Dendritic pattern Simulation

Synthesis of a novel benzoxazine containing benzoxazole structure

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Chinese Chemical Letters 2010年第5期21卷 558-562页

作者： Po Yang,Yi Gu State Key Laboratory of Polymer materials engineering,college of Polymer science and engineering, Sichuan university,Chengdu 610065,china [a] State Key Laboratory of Polymer materials engineering College of Polymer Science engineering Sichuan University Chengdu 610065 China

A high-purity benzoxazine（Boz-BOA） containing benzoxazole structure was successfully synthesized by three-step synthetic method using 2-（4-aminophenyl）-1H-benzoxazole-5-amine（BOA） and *** structure of Boz-BOA was confirmed by FTIR and;H NMR *** DSC was utilized to probe the curing behavior of Boz-BOA and exhibited a narrow melting peak and curing exothermic peak.

关键词： Benzoxazine Benzoxazole Synthesis Characterization

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 materials(Taiyuan university of Technology),Ministry of Education,Taiyuan 030024,china 2college of materials science and engineering,Taiyuan university of Technology,Taiyuan 030024,china 3college of Chemistry and Chemical engineering,Taiyuan university of Technology,Taiyuan 030024,china Key Laboratory of Interface science and engineering in Advanced materials (Taiyuan university of Technology) Ministry of Education Taiyuan 030024 China college of materials science and engineering 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 P123 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 P123 are critical to the formation of the *** coercivity value(231.91 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

Practical stabilization of receding-horizon control

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Journal of Central South university of Technology 2001年第4期8卷 268-271页

作者： LIU Bi yu,GUI Wei hua,MU Min (college of Information science and engineering, Central South university, changsha 410083, china) 1. college of Information science and engineering Central South University 410083 Changsha China

The purpose of this work is to propose a scheme to stabilize the predictive control systems in the practical stability sense. In the paper, the authors dealt with a general discrete predictive control system x j+1|t =f(x j|t , u j|t ) by using the Lyapunov direct method combining with receding horizon control technique, and presented a new condition to guarantee the practical stabilization of the systems. With the proposed results, one can design the optimal controllers easily to practically stabilize the predictive control systems.

关键词： receding-horizon control practical stability Lyapunov function nonlinear system optimization

FLUID KINETICS PRINCIPLE AND DESIGN CRITERIA OF ATOMIZER

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中国有色金属学会会刊：英文版 1996年第3期6卷 108-112页

作者： Chen Shizhu Zhou NaiJun Yin Zhimin(Department of materials science and engineering,Central South university of Technology, changsha 410083) CENT S UNIV TECHNOL DEPT MAT SCI & ENGNCHANGSHA 410083PEOPLES R CHINA

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关键词： atomizer fluid medium fluid kinetics vorticit