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Ceria-based Al2O3 composite electrolytes were prepared using (CeO2)0.6(SmO1.5)0.2(GdO1.5)0.2 (C6S2G2) and Al2O3 powders, employing sol-gel and low temperature combustion synthesis methods (SGLCS). The influence of Al2O3 content on the sintering behavior and electrical properties was studied. The results showed that electrical properties could be improved by adding 10wt% Al2O3. The sintered density was up to 5.61g/cm3. Most measurements of open circuit voltage (OCV) ranged between 0.8 and 1.2V; an OCV value of 1.15V was obtained at 370oC. The performance of intermediate- temperature solid oxide fuel cells (ITSOFCs) with a properly Al2O3 doped electrolyte was better than when a pure ceria-based one was used. The highest power density was 200mWcm-2.

The mechanisms of densification during laser ignited reaction sintering of Ni-Al-Cu powder materials were studied. With the addition of Cu, densification of Ni-Al-Cu specimens made of big particles was realized under laser rapid ignition and sintering without signification change of the final products. Filling of the mixture of liquid and disintegrated small grains or particles was regarded as the dominant mechanism for the final densification.

Abstract: Ceramic ZrO2 and metallic Ti–6Al–4V alloy are jointed by using a Ti33Zr17Cu50 (at.%) amorphous alloy as a solder at 1123–1273K in a high vacuum. It is demonstrated that the microstructure and mechanical properties are significantly influenced by the brazing temperature, the heat time and the cooling rate. The brazing seam jointing ZrO2 with Ti–6Al–4V is composed of ZrO2/Cu2Ti4O, (Ti,Zr)2Cu/TiO, Ti2O/CuTi2, (Ti,Zr)2Cu/CuTi2/Ti–6Al–4V alloys and compounds, of which the increasing thickness weakens the shear strength as the brazing temperature, the heat time the cooling rate increase. The maximum shear strength of the brazing joints reaches 162MPa with the optimal technical parameters: the brazing temperature of 1173K, the heat time of 10min and the cooling rate of 5K/min. The fracture of the joint occurs in the brittle seam layer nearby the side of ZrO2. [Copyright &y& Elsevier]

Abstract: TiC/Ni3Al composites have been obtained in situ by laser ignited self-propagating high-temperature synthesis (LISHS) of an intimate mixture of compacted powders of elemental C, Ti, Ni and Al. Ignition temperature (T ig) and combustion temperature (T c) are investigated; the effects of Ni3Al content on density, phase composition, microstructure of the reaction products and particle size of the synthesized TiC were studied. The results show the density of the products varies with Ni3Al content, and a maximum value of density appears at 50wt.% Ni3Al; TiC and Ni3Al are the two stable phases after SHS, TiC particle size decreases with the increasing of Ni3Al content, however, the decreasing of grain size is unobvious when Ni3Al content is over 60wt.%. [Copyright &y& Elsevier]

Abstract: TiC x has been formed by self-propagating high-temperature synthesis (SHS) from elemental powder mixtures with a range of C/Ti ratios. The combusting behavior of the powder mixtures was investigated. The effect of the processing variables on the lattice parameter and the composition of TiC were examined. The results show that lattice parameters of TiC x increase with the increase of C/Ti ratio. The variation of Gibbs free energy in Al-Ti-C system was studied based on the thermodynamics theory. The results show that TiC and Al3Ti phases are easier to form than Al4C3 phase. [Copyright &y& Elsevier]

Polycyclic aromatic hydrocarbons (PAHs) are of concern to the environment due to their carcinogenic properties (Neff 1979). Major activities which produce PARs are: combustion of fuels in vehicular engines, power generation from fossil fuels, coke production, wood burning, incineration of industrial and domestic wastes, oil refinery and chemical engineering operations, etc. (Baek et al. 1991). The existence of permanent pollution sources results in the accumulation of PAH in soil, plants and water bodies (Trapido 1999). In the last 100 years, the occurrence of PARs in soil, especially in urban areas, has increased significantly (Jones et al. 1989). Extensive researches have been carried out (Trapido 1999; Wilcke et al. 1999). In China, however, most studies have only focused on a limited number of compounds, especially benzo[a]pyrene (He et al. 1995; Songet al. 1995). Soil is one of the most important storage and transfer media for PARs in the environment. In the soil, the concentrations and distributions of PAHs are subject to redistribution and transformation processes. They particularly accumulate in organic matter-rich horizons because of their persistence and affinity for soil organic matter (Wilcke et al. 1996). The further pathways of PAH dissipation in contaminated soil may be volatilization; irreversible sorption, leaching, accumulation by plants, and biodegradation (Reilley et al. 1996). Located in the eastern part of the North China Plain, about 150 km east of Beijing, Tianjin is one of the largest industrial cities in China. In recent years, with rapid development of the economy, soil pollution is becoming more and more serious. It is well known that the concentrations of most PAR compounds are unevenly distributed in soil profiles due to a couple of reasons. The assessment of polluted soil is essential to determine the utilization of the land for multi-purposes. In this paper, the distribution and sources of PAR compounds in soil profiles of Tianjin area are studied. [ABSTRACT FROM AUTHOR]

Abstract: The laser surface cladding of an AZ91D magnesium alloy with Al and Al2O3 powders was investigated using a pulsed Nd:YAG laser. The optimum ratio of Al to Al2O3 and the suitable range of laser processing parameters were identified. The resulting microstructure in the modified surface layer was examined and the wear resistance property was evaluated. The results show that the wear resistance of the laser treated samples was much superior to that of the untreated samples. [Copyright &y& Elsevier]