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Cure Reaction Kinetics of Low Pressure Sheet Molding Compound System Thickened by Crystalline Polymer

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Journal of wuhan University of technology({2.s science) 2007年第2期22卷 380-384页

作者：秦岩 school of materials {2. and engineering Wuhan University of Technology

Several kinetic models for unsaturated polyester cure reaction and some existing parameter estimation techniques of these models were introduced. Correlated kinetic parameters and kinetic equations of the autocatalytic empirical kinetic model of LPSMC system were determined by using isothermal DSC to scan the system which was thickened by crystalline polymer （PEG-MAH）. Through using a serial curing degree of the system to validate the model, the experimental results were basically identical with the predictions of the autocatalytic empirical kinetic model. This model could provide a theoretical reference to the determination of molding techniques of low pressure SMC.

关键词： low pressure SMC curing kinetics model crystalline polymer

NUMERICAL STUDY OF CAVITATION ON THE SURFACE OF THE GUIDE VANE IN THREE GORGES HYDROPOWER UNIT

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Journal of Hydrodynamics 2010年第5期22卷 703-708页

作者： PENG Yu-cheng CHEN Xi-yang CAO Yan HOU Guo-xiang school of energy and Power engineering Huazhong University of Science and Technology Wuhan 430074 China College of Electronic Information engineering Wuhan Polytechnic Wuhan 430074 China school of Traffic science and {2. Huazhong University of Science and Technology Wuhan 430074 China

Large-area erosions such as rust and obvious cavitation were found on the surface of the guide vane in Three Gorges hydropower units. A numerical explanation of the cavitation is given in this article. At first, based on the characteristic performance curves of the prototype hydro-turbine supplied by ALSTOM together with the actual operating conditions, an operating point is chosen for numerical analysis using the Reynolds-Averaged Navier-Stokes （RANS） equations. The flow passages from the inlet of the spiral case to the outlet of the draft tube are included in the computational domain. The results show that the static pressure on the guide vane surface is much higher than the critical pressure of cavitation. Secondly, a tiny protrusion on the guide vane surface is considered and the problem is simplified to a 2.D problem to study the local detailed flow near the guide vane surface. The protrusion is 0.5 mm in height and is 5.0 mm in width. On the basis of the results of RANS simulations, the 2.D problem is studied using the Large Eddy Simulation （LES）. It is shown that there exists a region in which the static pressure reaches a level below the vapor pressure of the water. Thirdly, a cavitation model is included for the 0.5 mm protrusion case and another tiny pit case, with a tiny pit 0.3 mm in depth and 1.0 mm in width. The results show that vapor bubble exists at the protrusion entrance and the pit exit as the low pressure regions.

关键词： cavitation guide vane numerical analysis

Ti(C, N) BASED CERAMETS AND ITS FRACTAL ANALYSIS OF FRACTURE SURFACES

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中国有色金属学会会刊：英文版 1996年第2期6卷 101-104页

作者： Liu Ning(Department of materials science and {2.,Anhui institute of technology, Hefei 2.0069)Hu Zhenhua Cui Kun(Huazhong University of science and technology, wuhan 430074) Department of materials science and {2. Anhui Institute of Technology Hefei 230069 China Huazhong University of science and technology Wuhan 430074 China

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关键词： Ti(C, N) based ceramets fracture surface fractal analysis

Preparation and Absorption/Desorption Performance of Gypsum-based Humidity Controlling materials

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Journal of wuhan University of technology({2.s science) 2011年第4期26卷 684-686页

作者：姜洪义 school of materials {2. and engineering Wuhan University of Technology

Absorption/desorption properties of some humidity controlling materials which contain gypsum as basic cement materials and activated Sepiolite powder as humidity controlling media were tested. The kinetics curve of moisture adsorption/desorption were drawn and humidity controlling performance in nature environment was verified. The experimental results show that moisture absorption/desorption rates are increased, and the speed is also accelerated. These materials, which can adjust environmental humidity effectively, are new ones with good humidity controlling performance.

关键词： activated Sepiolite gypsum-composites humidity controlling performance

Sticking-up Behaviors and Surface Friction of IF Electrogalvanized Sheet Steel in Forming

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International Journal of Minerals,Metallurgy and materials 1999年第1期13卷 61-63,68页

作者： Jiming Hu Jixun Wu Yanping Lu Yanrong Zhu (material science and engineering school, University of science and {2. Beijing, Beijing 100083, China) Univ of science and technology Beijing Beijing China

X-ray diffraction (XRD), ball-disc friction and wearing machine and draw-bead test were introduced to investigat the strcusture and workability of IF sheet steel electrogalvanized deposits prepared from sulphate solution system. It was shown that the picking-up of the zinc coating on die strengthened with the increasing of friction factor which was originally affected by the coating's structure. Duing forming, (00X) planes (X= 2. 4) preferential orientation of zinc deposits increased, which resulted in enhanc ing the coating's friction behaviors. Therefore, the forming mechanism of electrogalvedzed deposit was demonstrated that both friction and the stricking -up behaviors of the coating are intensified simultaneously and affect each other.

关键词： electrogalvanized deposit forming friction factor

Effects of NaNbO_3-Co_2._3 Co-additive on the Properties of PZN-PZT Ceramics

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Journal of wuhan University of technology({2.s science) 2007年第4期22卷 722-724页

作者：邓毅华 College of material science and {2. South China University of Technology Department of Electronic science and technology Huazhong University of Science and TechnologyWuhan 430074China

NaNbO3-Co2.3 co-added PZN-PZT （PZCNNT） ceramics were prepared using conventional solid state reaction. The piezoelectric and dielectric properties were measured. The experimental results show that the addition of 0.3mo1% Co2.3 leads to low dielectric loss （tgδ） in PZCNNT ceramics and the proper addition of NaNbO3 not only improves piezoelectric properties but also decreases intensively dielectric loss and mechanical loss. The optimal ceramic having d33=310 pC/N, kp=0.59, εr=985, tgδ=0.0034, Qm=1380 was obtained.

关键词： PZN-PZT piezoelectric constant dielectric constant dielectric loss

Comparison of Ferrite Refinement Mechanisms by Different Processing Schedules in 08 and 2.Mn Steels

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Journal of University of science and technology Beijing 2001年第3期8卷 218-223页

作者： Ping Yang Feng’e Gui, Shicai Ma material science and engineering school, University of science and {2. Beijing, Beijing 100083, China material Sci. and engineering Sch. Univ. of Sci. and Technol. Beijing Beijing 100083 China

The influence of deforming temperature on ferrite refinement was analyzed by comparing the microstructures obtained by deformation at above A(r3), in two-phase region of (alpha + gamma) and at below A(t) in clean 08 and 2.Mn steels. The results indicate that ferrite refinement through strain induced transformation by deformation at above A(r3) is more effective than that by deformation simply through ferrite dynamic recrystallization. The main problem of ferrite refinement by deformation at below A(r3) is the inhomogeneity of microstructure which is controlled by the orientations and sizes of ferrite grains and the distribution of second phases. Ferrite dynamic recrystallization after strain induced transformation can further effectively refine ferrite.

关键词： clean carbon steel strain induced transformation grain refinement ferrite dynamic recrystallization

Structure and Properties of Mg-doped SrBi_4Ti_4O_(15) Bi-layered Compounds

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Journal of wuhan University of technology({2.s science) 2008年第5期23卷 675-677页

作者：郝华 school of materials {2. and engineering Wuhan University of Technology State Key Laboratory of Advanced technology for materials Synthesis and Processing Wuhan University of Technology

The structure and properties of Mg-doped SrBi4Ti4O15（SBT） were dicussed. Mg substitution into SBT had two possibilities states with the dopant amount variety. Mg cation substituted mostly into Sr^2. and the amount proportion was 68.11%.Mg ion will substitute into Ti ion site in perovskite layer when the doping amount increases. Polarization increases sharply when x=0.1 and then decreases becauses of the domain pinning. The Curie temperature of Mg-doped SBT is about 300 ℃ and there is a broad diffuse phase transition near Tc with a flat peak near the Ta of SBT.

关键词： Mg-doped bismuth layer structure ferroelectrics ferroelectric properties

Chitosan——L-Lactic Acid Scaffold for the Regeneration of Peripheral Nerve and Its NGF Release Properties

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Journal of wuhan University of technology({2.s science) 2009年第6期24卷 961-964页

作者：徐海星 Department of Pharmaceutical engineering School of Chemical EngineeringWuhan University of Technology

Chitosan—L-lactic acid composite scaffold for the regeneration of peripheral nerve is obtained by grafting L-lactic acid onto the amino groups in chitosan with combined vacuum freezer drier. The composite scaffold was characterized by ATR-FTIR and SEM. The scaffold has a better graft efficiency and has a dense inner layer and a loose outer layer with porous structure, and the pore size is about 100 μ*** NGF release properties of the scaffold were investigated. The experimental results showed that, at the 1st day, 15.2.ng of NGF on average was released from the scaffold. From day 2.to day 10, the release rate obviously slowed down and 1.64 ng of NGF was released on average every day. After 10 days, the release rate was slower and 10.3 ng of NGF was released on average every day. After 60 days, NGF could also maintained a certain concentration. These properties show that the scaffold is a better carrier for NGF which can be more advantageous to the regeneration of the damaged peripheral nerve. As a result, this composite scaffold would be an ideal candidate for the regeneration of damaged peripheral nerve.

关键词： chitosan L-lactic acid peripheral nerve NGF release properties