Advanced Materials Research Vols. 986-987

Abstract: Graphene oxide (GO) was prepared via ultrasonic assisted chemical oxidation method. Contrasting with modified hummers method, GO prepared by ultrasonic assisted chemical oxidation method showed thinner flakes, the interlayer spacing increases. The emission spectra of the GO showed a similar excitation-dependent feature with the strongest peak (552 nm) excited at 477 nm.

Abstract: We report on the preparation and hydrogen desorption/absorption kinetics of nanocrystalline magnesium hydride (MgH₂) added commercial TiO₂ by high-energy ball milling. The phase and composition of the as-milled powders are characterized by X-ray diffraction (XRD). The results show that the milled sample contained MgH₂ phase, small amount of Mg and various phases of TiO₂ such as tetragonal and orthorhombic structure. The effect of the milling time (10, 20 and 30 h) on the hydrogen desorption property of MgH₂ has been investigated and found that the milling time of 20 h has excellent dehydrogenation properties, which can release 3.3 wt% H₂ within 60 min at 300 ^oC, which indicates that the kinetics of hydrogen desorption of MgH₂-TiO₂ composite has been greatly enhanced compared to the pure MgH₂. Moreover, hydrogen absorption kinetics of the sample milled 20 h has been studied and the hydrogen content is 0.7, 0.8 and 1.2 wt% H₂ at 250, 280 and 300 ^oC within 60 min, respectively.

Abstract: Material balance calculation was adopted to a wet flue gas desulfurization (WFGD) system for exploring impacts of gas-gas heater (GGH). Effects of GGH on flue and water consumption were analyzed. Results showed that inlet flue temperature of desulfurization tower reduced by 3.4 °C at 100% load after installation of GGH. Exhausted gas temperature of system increased by 34.9°C. The heat release of original flue in desulfurization tower reduced by 43.72%. Plume rise height was significantly improved. Water evaporation in desulfurization tower declined by 42.07%.Amount of addendum water reduced by 39.06%, and water vapor carried by flue decreased by 19.78% at the outlet of WFGD. Therefore, operation condition of flue emission is improved and water consumption decreases with GGH.

Abstract: In this paper, a realistic 3D numerical model is established to investigate the flow distribution of a 10-cells short planar SOFC stack. The effect of the basic geometric parameters, such as the sub-manifold radii () and the single channel width (), on the stack flow uniformity is examined. And the results and discusses are presented in this paper. This investigation for the SOFC stack holds great significance for the SOFC stack commercialization.

Abstract: Preparing sodium methoxide by reacting sodium hydroxide with methanol was investigated. The chemical equilibrium constant was small. Removing water out of the reaction phase could drive the reaction to produce more sodium methoxide. The experiments were carried out at different temperatures and 1 atm in semi-batch reactor by liquid evaporating to remove water. The effects of initial sodium hydroxide concentration and liquid evaporating speed were discussed. A mathematical model coupling reaction with separation processes was built and the predicted results by the model were in good agreement with experiment results. The model provides useful information for industrial simulation.

Abstract: The HTV SIR provided the superior hydrophobicity for the composite insulator. But it faces the aging problem more than the inorganics. Corona, as an inevitable influence factor in insulator’s operation, its effect to the material could not be ignored. The paper developed a multi needles to plate corona aging equipment, 1000 hours’ corona aging to the HTV SIR was done. The duration of corona aging effect was study by FTIR, SEM and volume resistivity-temperature character testing. Three testing methods from the aspect of material’s chemical, physical and electrical characters to evaluate the aging effect with time went on. It had good consistency in all three methods for HTV SIR’s corona aging evaluation.

Abstract: The paper describes synthesis and evaluation of polymeric additives for improving the flow properties of lubricating oils. The polymer (AAV) was prepared by the free-radical initiated polymerization of methacryl esters (A₁₄) with acrylamide and vinyl acetate. A₁₄ and AAV were characterized by infrared spectroscopy (IR). Three lubricating oils were selected as the test oil samples and the effect of solidification point depressant (ΔSP) with different mass fractions and other physicochemical characteristics of the samples with and without AAV added were investigated. In order to analyze the effect of AAV on the viscosity of lubricating oils, viscosity-temperature curves were plotted. The results showed that AAV not only had a good effect on dropping solidifying point for Yanshan lubricating oils, but also had a good effect on dropping viscosity; what’s more, other physicochemical characteristics of lubricating oil have little changes before and after AAV added.

Abstract: A flat plate model are employed to investigate the development mechanism of the initial electrons along the insulation surface in this paper, and the field emission properties of pollutant (NaCl) and water (H₂O) adsorbed on the copper electrode are studied. The voltage when partial arc occurs is computed and a flat plate experiment is carried out to validate the computing results. Results indicate that pollutant and water have an important impact on the field emission, where pollutant is more significant than water. Meanwhile, the pollutant and water can increase the probability to form the partial arc.

Abstract: By describing the main affecting factors of the small electric vehicles cycle life for the lead-acid batteries,then studying the main technical measures that how to improve the deep cycle performance of the batteries to prolong its life.When the methods of the combination of grid alloys ,mixing paste and curing process parameters control, the selection of the negative organic additives and the sets mode of the positive and negative plates were used,the battery performance and the cycle life greatly improved and the failure rate decreased.

Abstract: The proton exchange membrane (PEM) plays a key role on performance of PEM fuel cell. This paper reviewed recent developments of perfluorinated and partially fluorinated PEMs for PEM fuel cells.Comparative analysis of various PEM parameters was presented. Perfluorinated sulfonic PEMs with better technology have the issues of complicated preparation process and high cost.Partially fluorinated PEMs have lower price,but performance is not good enough.