Advanced Materials Research Vols. 887-888

Abstract: A 100μm silicon carbide epilayer with mean doping concentration 6×10¹⁴ cm^-3 was achieved on 3 inch silicon carbide substrate using a growh rate of 30 μm/h. Hydrogen gas foil rotation was adopted to improve the doping uniformity. The intra-wafer thickness and doping uniformity was 1.83% and 7.51%, respectively. Schottky diodes fabricated on this epilayer presented a breakdown voltage of 10kV. This is the first report of 10kV schottky diodes fabricated on silicon carbide epilayer made in China.

Abstract: In this study, a certain amount of Cerium and Arsenic were closed in the barrel-shaped cylinder machined by H08 steel, heated to 1173 K for 50 h, and the interaction among the cerium, arsenic and iron in the barrel-shaped cylinder was studied by X-ray diffraction, optical microscopy and electronic probe microscopy analysis. The result shows that the gray phase is the ternary compound Ce₁₂Fe_57.5As₄₁, and the ternary compound Ce₁₂Fe_57.5As₄₁ is the main interaction product when the atomic ratio of Ce to As is 1:3. The eutectic compound Fe₂As can be precipitated from ferrite with the temperature decreasing.

Abstract: The emission mechanism of biodiesel used on IC engine is analyzed, as well as the summary of the research of domestic and abroad situation about biodiesel used on IC engine. The improved measures, which is under the premise of not affecting power performance and economic efficiency of IC engine, combining the emission process of IC engine was presented, it needs some measures to improve the quality of biodiesel and the system of IC engine to control the emission of the harmful substances, in this way the problem of energy shortage and environmental pollution can be ameliorated.

Abstract: Solar Salt is the best hot transfer medium molten salt of solar thermal power generation.In order to study the hot corrosion behavior of four graphite is in the molten Solar Salt.The graphite immersed equipped with molten salt crucible placed in a muffle furnace,each period of time remove the sample and weight the weight gain until the sample is completely destroyed.The destruction forming of graphite is analyzed by XRD, SEM and OP.The study found that the order of hot resistant corrosion of molten Solar Salt of four graphite materials are the fine structuregraphite,isostatic graphite,9# graphite and cold pressing graphite.The principal factors can affect hot corrosion resistant of graphite is the graphitization degree. The hot corrosion resistance of the graphite can be enhanced with the increase of graphitization degree.

Abstract: As a high quality alternative of fossil diesel, biodiesel is widely concerned at domestic and abroad for its environmentally friendly and renewable. Oxidation stability is one of the important properties of biodiesel, which is also one of the quality criteria in storing and using. The oxidative mechanism and the influencing factors of Oxidation stability, oxidation stabilitys evaluation methods and the application of biodiesel antioxidants were reviewed. Then the direction of oxidation stability is put forward.

Abstract: The SiC composites with good oxidation resistance were fabricated via semi-dry pressing and pressureless firing in the air. The SiC, talc, kaolin, alumina, BN and H₃BO₃ were used as starting materials. Sample B2 fired at 1280 °C had the optimal physical properties with a bending strength of 85.84 MPa. Sample B3 contained 1 wt% H₃BO₃ and fired at 1300 °C for 2 h had the best oxidation resistance. After oxidized at 1000 °C for 50 h, the weight gain and oxidation rate constant of sample B3 were 3.3990 mg/cm² and 0.52×10^-4 g²/(cm⁴·s) respectively. The oxidation products of SiC, BN and H₃BO₃ could generate SiO₂-B₂O₃ film and improve the oxidation resistance effectively. It is believed that these SiC composites should be a promising candidate in solar absorber coating.

Abstract: High pressure hydrate experiment device was used to research the influence of active carbon to the hydrogen storage characteristics of THF hydrates in volume 502.4 ml and 1°C. The results show that within the experimental pressure range, the induction time changes irregularly, so active carbon has no apparent effect on the induction time, but has obvious influence to the pressure drop, under same initial pressure, the pressure drops with activated carbon are larger than that without activated carbon; With activated carbon, the higher the initial pressure the larger the pressure drop. Because the pressure drop is proportional to the hydrogen storage density, so the larger the pressure drop, the higher the hydrogen storage density. When the initial pressure is 8.4 MPa, with activated carbon the hydrogen storage density (0.0082wt%) is far higher than that (0.0031wt%) without it. So activated carbon can promote the hydrogen storage density of THF hydrate.

Abstract: In the Ni-MH power battery electrodes manufacturing, the quality of the electrode material admixture will affect electrode and the whole function of batteries directly. However, the electrode material admixture process is very complex. It is very difficult to build up a model of precision to carry on control to the system. The traditional electrode material admixture control of the process, mainly according to develop the personnel on trial and the spot experience to complete, That method basically can not reach the good control appearance. The Fuzzy control can resolve the problem of this complication nicely.

Abstract: Orthogonal experiment of producing biodiesel needs to collect large volume of experimental data. In order to save time, factors which influence the yield of biodiesel were analyzed by combining Mass Action Law with Arrhenius equation and the reaction rate equation of biodiesel yield was determined when esterification reactions go along with the same amount of catalyst. At the same time, it provides the theoretical guidance to obtain the optimum reaction conditions.

Abstract: Objective To obtain immobilized alpha-glucosidase with good biological activity and improve the utilization rate of alpha-glucosidase. Methods Prepare the core-shell microparticles consisting of poly (methyl methacrylate) (PMMA) cores surrounded by various of chitosan shells, induced by tert-butylhydroperoxide (TBHP). Then fixed the alpha-glucosides N-terminal onto the carriers and studied the optimum immobilization conditions and the property of alpha-glucosidase immobilized.Result Immobilized α-glucosidase enzyme pH stability was higher than the free. In particular, the relative enzyme activity were maintained at 80% in the range of pH4.5 ~ 6.5. Immobilized α-glucosidase optimum temperature is 60 °C, the optimum temperature of the free enzyme is 50 °C. Conclution These Alpha-glucosidase Immobilization can be used as biopolymer and biomaterials in the pharmaceutical and medical application fields.