Advanced Materials Research Vols. 989-994

Abstract: The electron beam-physical vapor deposition (EB-PVD) coatings were selected to analyze the fatigue life. Firstly the failure mechanisms of oxidation and thermal fatigue of TBCs were considered together. The weight of thermally grown oxide (TGO) were measured during oxidation experiments and modeled. Thermal fatigue experiments were induced by thermal mismatched stress and thermal fatigue with holding time. The failure mechanism was obtained by the finite element analyses. The life prediction model was modified by the shear and normal strain range close to the interface of the top coat and TGO. Based on the experiment data, the life prediction model of thermal fatigue of TBCs was set up for EB-PVD coatings. Finally, using the life prediction model, the life of TBCs was predicted under the designed load case. The life prediction model was verified and all experiment data fall into the factor of 3 scatter band.

Abstract: The shape memory effect,the classification and the principle of shape memory alloys are introduced.The performance features such as melting point,density, resistivity,thermal conductivity, thermal expansion coefficient, phase change heattensile strength fatigue limit, grain size, transition temperature,lag size,one-way shape memory, two-way shape memory of Fe-based,Cu-based and Ti-Ni based shape memory alloys are researched in detail.

Abstract: Al co-doped ZnCoO thin film has been prepared by a sol-gel method. The structural and optical properties of the sample were investigated. X-ray diffraction and UV absorption spectroscopy analyses indicate that Al³⁺ and Co²⁺ substitute for Zn²⁺ without changing the wurtzite structure. With the Al doping, the visible emission increased and the UV emission decreased, which is attributed to the increase of O vacancies and Zn interstitials.

Abstract: The most probable mechanism function of non-isothermal kinetics about polyvinyl chloride thermal decomposition process was studied by the differential method (A-B-S)-integral method (C-R). The results show that the most probable mechanism function accorded with the mechanism function A1.5 when the heating rate of was 5 °C/min and the decomposition rate was 0.01-0.10.

Abstract: A novel polyacrylic acid/rice straw (PAA/RS) composite superabsorbent was prepared. The factors that can influence the water absorption of the composite were investigated, including the concentration and neutralization degree of AA, the weight ratios of N, N’-methylenebisacrylamide (MBA) to AA and RS to AA. The results show that gel effect plays a key role in the preparation of PAA/RS composite. The addition of an appropriate amount of rice straw to the composite can significantly improve the water absorption. Under the optimized condition, the water absorption of the prepared PAA/RS composite was 285.4 g/g. The composite exhibits good loading and slow-release properties for urea and is promising in agricultural and horticultural applications.

Abstract: Catalytic combustion of VOCs was investigated over Mn–Zn mixed oxides supported on cordierite ceramic (Cord) and over the promoted Mn-Zn oxides with γ–Al₂O₃ coating. The properties and performance were characterized by using the XRD, SEM, BET, and TPD techniques. Mn-Zn oxides catalysts with different kinds of γ–Al₂O₃ sol coating were found to possess a high activity, and the Mn–Zn/γ–Al₂O₃/Cord (Mn/Zn=2) was identified as the most active that the temperature of complete combustion of toluene was 250°C. Effects of variation of preparation conditions, including molar ratio of Mn and Zn, loading, calcination temperature and different kinds of γ–Al₂O₃ dipping were investigated.

Abstract: An ionic liquid 1-butyl-3-methylimidazolium hydroxide ([Bmim]OH) was grafted on silica gel by post-grafting method. Such grafted ionic liquids (GILs) which were verified by means of FTIR, element analysis N₂ adsorption-desorption and TG could be used as highly effective heterogeneous catalysts toward propylene carbonate synthesis through cycloaddition of carbon dioxide with propylene oxide under solventless and mild conditions.

Abstract: Systematic research on monomolecular layer of copper (II) phthalocyanine (CuPc) and porphyrin derivatives bas been done. In this paper an attention is focused upon the molecular orientation in monomolecular layer of some symmetrically substituted porphyrin and asymmetrically substituted CuPc derivatives by means of the surface pressure-area (π-A) isotherm method, polarized UV-visible spectra.

Abstract: The new wheel could reduce grinding friction and prevent of chip adhesion by lubrication between wheel and workpiece surface. Investigation of the simulation dry grinding Ti6Al4V alloy with monolayer brazed CBN (cubic boron nitride) and diamond grinding wheels, and systematically studies the effect of process parameters on the microstructure of specimen. the cutting properties generated during grinding with internal lubricating wheel. Grinding simulation was carried out with this internal lubricating wheel. The machining properties were assessed in terms of grinding temperature. The results indicate that graphite significantly improve machinability during dry grinding of Ti6Al4V alloy.

Abstract: We conduct first-principles total-energy density functional calculations to study the ScB₂ (0001) surfaces. The optimized surface structures and electronic properties are obtained. The results show that Sc-terminated surface is thermodynamically more favorable in most of range. The relaxations indicate that it is mainly localized within top three layers and it is less relaxation for Sc-terminated surface. The surface induced features in DOS disappear slowly for the B-terminated surface but vanish rapidly for the Sc-terminated surface. For the Sc-terminated surface, it shows strong metallic property. Simultaneously, both termination surfaces are found charge accumulation relative to the idea surface. Sc-B bonds are strengthened result in the outermost interface spacing are all contracted.