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A series of ZSM-5 samples with similar SiO2/Al2O3 ratio was synthesised using different aluminum sources and by including varying amounts of calcium hydroxide during the synthesis.
The samples were subsequently ion-exchanged with Cu-ions, and evaluated with respect to deNOx activity in the absence and
presence of water. The choice of aluminum source and the presence of calcium hydroxide during the zeolite synthesis affected
the lean deNOx activity of Cu-ZSM-5. 相似文献
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Miniaturization of Bi2Te3 compounds is of great interest in semiconductor industries due to their distinct anisotropic thermoelectric properties at room temperature. The aim of the present work was to investigate the mechanism of the electrodeposition of Bi2Te3 compounds on stainless steel substrates and relate the morphology and composition of the resulting deposits to experimental parameters. Cyclic voltammetry (CV) experiments in acidic solutions containing Bi3+ and/or HTeO2+ ions show that the deposition potential for the Bi2Te3 compound is more positive than either of the single elements alone. A detailed mechanism of the co-deposition was obtained by varying the concentrations of the two elements and evaluating the corresponding morphological and compositional changes of the deposits. The results show that the deposition of Te is kinetically hindered and that Bi deposition plays a major role during the co-deposition. 相似文献
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Ola Lyckfeldt Lisa Palmqvist Elis Carlström 《Journal of the European Ceramic Society》2009,29(6):1069-1076
Solvent mixtures of water and ethanol and water and isopropanol have been evaluated for processing of concentrated alumina suspensions. The addition of alcohols may increase the long-term stability of suspensions with soluble ceramic species such as magnesia, which is added as a sintering aid. A poly(acrylic acid) and a hydrophilic comb copolymer were used as dispersants for the different solvent mixtures. The aim was to compare the stabilization efficiency at normal processing conditions, pH 9–10, through rheological measurements and to develop a robust system including magnesia with long-term stability. The electrostatic stabilization of the dispersants in the different solvent mixtures was studied by zeta potential measurements. Highly negative zeta potentials were observed for the poly(acrylic acid) at pH 9–10 in the solvent mixtures. A charge contribution was also seen from the adsorbed comb copolymer, however smaller than for the poly(acrylic acid). Low viscosity was obtained for suspensions stabilized with poly(acrylic acid) in solvent mixtures with either 25 vol% ethanol or isopropanol. Higher alcohol to water ratio led to flocculation of the suspension when poly(acrylic acid) was used as dispersant. Alumina suspensions with added magnesia in isopropanol:water 25:75 and poly(acrylic acid) as dispersant showed long-term stability. The viscosity remained almost constant during 4 days of aging. Suspensions stabilized with the comb copolymer dispersant gave stable systems with ethanol and isopropanol concentrations between 25 and 75 vol%. The superior dispersing efficiency of the comb copolymer at alcohol contents above 25 vol% was believed to originate from steric stabilization in combination with low effective particle size, giving low viscosity through lower apparent solid contents of the suspension. 相似文献
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于魁 Diego Perez 赵伟 Chie Fuyuki 傅昌瑞 Jtravis B Russett 戴璞 Irmgard Reiter Rasmus Palmqvist 覃立超 谢新宇 《建筑技艺》2011,(Z3):91-93
重庆是中国最年轻的直辖市,城市规划建设大有可为,完全有条件建成一个大家公认的宜居城市,一个环境优美的城市,一个交通顺畅的城市,甚至变成一个森林城市。一个有希望、有活力的地方,要敢于设想和设计自己的美好未来。——薄熙来(重庆市长) 相似文献
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Malin Berggrund Hanna Härelind Ingelsten Magnus Skoglundh Anders E. C. Palmqvist 《Catalysis Letters》2009,130(1-2):79-85
The influence of syntheses parameters of zeolite ZSM-5 on the lean NO x reduction activity and hydrothermal stability of Cu-ZSM-5 has been investigated. The hydrothermal stability of Cu-ZSM-5 was found to depend on the aluminium source used and on the presence of Ca(OH)2 in the synthesis mixture for ZSM-5. 相似文献
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Yi Ma Waruna Wijesekara Anders E. C. Palmqvist 《Journal of Electronic Materials》2012,41(6):1138-1146
Thermoelectric thin films of the ternary compounds (Bi x Sb1?x )2Te3 and Bi2(Te1?y Se y )3 were synthesized using potentiostatic electrochemical deposition on gold-coated silicon substrates from aqueous acidic solutions at room temperature. The surface morphology, elemental composition, and crystal structure of the deposited films were studied and correlated with preparation conditions. The thermoelectric properties of (Bi x Sb1?x )2Te3 and Bi2(Te1?y Se y )3 films, i.e., Seebeck coefficient and electrical resistivity, were measured after transferring the films to a nonconductive epoxy support. (Bi x Sb1?x )2Te3 thin films showed p-type semiconductivity, and the highest power factor was obtained for film deposited at a relatively large negative potential with composition close to Bi0.5Sb1.5Te3. In addition, Bi2(Te1?y Se y )3 thin films showed n-type semiconductivity, and the highest power factor was obtained for film deposited at a relatively small negative potential, having composition close to Bi2Te2.7Se0.3. In contrast to Bi2Te2.7Se0.3 thin films, an annealing treatment was required for Bi0.5Sb1.5Te3 thin films to achieve the same magnitude of power factor as Bi2Te2.7Se0.3. Therefore, Bi2Te2.7Se0.3 thin films appear to be good candidates for multilayer preparation using electrochemical deposition, but the morphology of the films must be further improved. 相似文献
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Stefanie Tamm Hanna H. Ingelsten Magnus Skoglundh Anders E. C. Palmqvist 《Topics in Catalysis》2009,52(13-20):1813-1816
Lean reduction of NO x with DME occurs with high selectivity to N2 over Al2O3 between 300 °C and 550 °C with a maximum of 47% at 380 °C, and with lower selectivity over Ag/Al2O3 between 250 °C and 400 °C due to the catalysts’ sensitivity to gas phase radical reactions and activity for NO x reduction with methanol. 相似文献