In this work, the effectiveness of V2O5-WO3/TiO2 catalysts modified with different CeO2 contents by impregnation and co-precipitation methods on the selective catalytic reduction of NOxby NH3 have been studied compara...In this work, the effectiveness of V2O5-WO3/TiO2 catalysts modified with different CeO2 contents by impregnation and co-precipitation methods on the selective catalytic reduction of NOxby NH3 have been studied comparatively by various experimental techniques. The results showed that the NO conversion of V2O5-WO3/CeO2-TiO2 catalysts modified by co-precipitation method obviously increased with the Ce doping contents in the studied range below 20%（All Ce contents are in mass fractions）, but the NO conversion of V2O5-WO3/CeO2/TiO2 catalysts modified by impregnation methods was lower than V2O5-WO3/CeO2-TiO2 catalysts especially beyond 2.5% Ce doping contents. The V2O5-WO3/CeO2-TiO2 catalysts showed better SCR activity, wider reaction window, and higher sulfur and water resistance. The characterization results elucidated that the modified catalysts by co-precipitation method exhibited higher specific surface area, much better dispersity of Ce component, more Ce^（3＋）species and more Br？nsted acid sites than that by impregnation. The vacancies caused by more Ce^（3＋）species were favorable for more NO oxidation to NO2, and the interaction between Ce species and WOxspecies generated more Br？nsted acid sites. It could be supposed that dispersed Ce Oxspecies and WOxspecies offered more second active centers respectively to adsorb oxygen and activate ammonia as co-catalysis to the primary active center of V ions, thus facilitated the better SCR activity of modified V2O5-WO3/CeO2-TiO2 catalysts by coprecipitation methods. The co-precipitation methods with Ce component were more suitable for production of modified commercial V2O5-WO3/TiO2 catalysts.展开更多
The complex of Rubisco and Rubisco activase from LaCl3-, CeCl3- treated spinach in vivo is induced. SDS-PAGE result shows that the purified proteins from LaCl3-, CeCl3- treated spinach have not only large and small su...The complex of Rubisco and Rubisco activase from LaCl3-, CeCl3- treated spinach in vivo is induced. SDS-PAGE result shows that the purified proteins from LaCl3-, CeCl3- treated spinach have not only large and small subunits (55 kD, 14.4 kD) of Rubisco, but also two large subunits of 45 kD and 41 kD near the large subunits of Rubisco. Native-PAGE shows that the purified proteins from LaCl3-, CeCl3- treated spinach have not only a band of Rubisco (560 kD), but also a band of about 1100 kD, about twice distant from Rubisco, which might be a complex of Rubisco and Rubisco activase. The purified enzyme activities from LaCl3-, CeCl3-treated spinach are 1.8 and 2.8 times that of the control,the intensities of absorption and fluorescence are sig- nificantly higher than that of the purified Rubisco from the control, and the total sulfhydryl groups and available sulfhydryl groups are 36—39 –SH per mol enzyme, 14—25 –SH per mol enzyme more than those of the purified Rubisco from the control, respectively. The CD spectra show that the secondary structure of the purified enzyme from LaCl3-, CeCl3 -treated spinach is very dif- ferent from the control. The enzyme activities from LaCl3-, CeCl3- treated spinach in vivo are 1.5 and 1.9 times those of the control.展开更多
The sulfate ions modified YAG：Ce^（3＋） phosphors were prepared by co-precipitation method and characterized by X-ray diffraction,transmission electron microscopy,and photoluminescence.Effects of sulfate ions on the...The sulfate ions modified YAG：Ce^（3＋） phosphors were prepared by co-precipitation method and characterized by X-ray diffraction,transmission electron microscopy,and photoluminescence.Effects of sulfate ions on the photoluminescence（PL） property of the as-prepared YAG：Ce^（3＋） phosphors were studied,with sodium dodecyl sulfate（SDS） being added to R^（3＋）（Ce^（3＋）,Y^（3＋）,Al^（3＋）） ions.Results indicated that pure YAG：Ce^（3＋） phosphors with different ratios of sulfate ions could be easily obtained by calcining the as-synthesized precursor at 950 ℃ for 2 h,the YAG：Ce^（3＋） phosphors with an optimal mass ratio of 3.5 wt.%SDS had the highest emission intensity and the best dispersion behavior,and the fluorescence decay of the as-obtained YAG：Ce^（3＋） phosphors was related to the lattice defect,reabsorption and cross correlation.Furthermore,thermal quenching properties of the YAG：Ce^（3＋） phosphors and the YAG：Ce^（3＋） phosphors with 3.5 wt.%SDS were also discussed,indicating that the YAG：Ce^（3＋） with SDS phosphors could have potential applications in the daylight LEDs or warm white LEDs.展开更多
基金Project supported by the Guangxi Natural Science Foundation(2014GXNSFAA118057)Guangxi Science and Technology Planning Project(AB16380276)
文摘In this work, the effectiveness of V2O5-WO3/TiO2 catalysts modified with different CeO2 contents by impregnation and co-precipitation methods on the selective catalytic reduction of NOxby NH3 have been studied comparatively by various experimental techniques. The results showed that the NO conversion of V2O5-WO3/CeO2-TiO2 catalysts modified by co-precipitation method obviously increased with the Ce doping contents in the studied range below 20%（All Ce contents are in mass fractions）, but the NO conversion of V2O5-WO3/CeO2/TiO2 catalysts modified by impregnation methods was lower than V2O5-WO3/CeO2-TiO2 catalysts especially beyond 2.5% Ce doping contents. The V2O5-WO3/CeO2-TiO2 catalysts showed better SCR activity, wider reaction window, and higher sulfur and water resistance. The characterization results elucidated that the modified catalysts by co-precipitation method exhibited higher specific surface area, much better dispersity of Ce component, more Ce^（3＋）species and more Br？nsted acid sites than that by impregnation. The vacancies caused by more Ce^（3＋）species were favorable for more NO oxidation to NO2, and the interaction between Ce species and WOxspecies generated more Br？nsted acid sites. It could be supposed that dispersed Ce Oxspecies and WOxspecies offered more second active centers respectively to adsorb oxygen and activate ammonia as co-catalysis to the primary active center of V ions, thus facilitated the better SCR activity of modified V2O5-WO3/CeO2-TiO2 catalysts by coprecipitation methods. The co-precipitation methods with Ce component were more suitable for production of modified commercial V2O5-WO3/TiO2 catalysts.
基金the National Natural Science Foundation of China(Grant No.30470150) the Natural Science Foundation of Jiangsu Province Universities(Grant No.03KJB180122).
文摘The complex of Rubisco and Rubisco activase from LaCl3-, CeCl3- treated spinach in vivo is induced. SDS-PAGE result shows that the purified proteins from LaCl3-, CeCl3- treated spinach have not only large and small subunits (55 kD, 14.4 kD) of Rubisco, but also two large subunits of 45 kD and 41 kD near the large subunits of Rubisco. Native-PAGE shows that the purified proteins from LaCl3-, CeCl3- treated spinach have not only a band of Rubisco (560 kD), but also a band of about 1100 kD, about twice distant from Rubisco, which might be a complex of Rubisco and Rubisco activase. The purified enzyme activities from LaCl3-, CeCl3-treated spinach are 1.8 and 2.8 times that of the control,the intensities of absorption and fluorescence are sig- nificantly higher than that of the purified Rubisco from the control, and the total sulfhydryl groups and available sulfhydryl groups are 36—39 –SH per mol enzyme, 14—25 –SH per mol enzyme more than those of the purified Rubisco from the control, respectively. The CD spectra show that the secondary structure of the purified enzyme from LaCl3-, CeCl3 -treated spinach is very dif- ferent from the control. The enzyme activities from LaCl3-, CeCl3- treated spinach in vivo are 1.5 and 1.9 times those of the control.
基金supported by the Research Fund for Doctoral Program of Higher Education of China(20120201130004)the Science and Technology Developing Project of Shaanxi Province(2015KW-001)+1 种基金the National Natural Science Foundation of China(61078058)Partially by the National Natural Science Foundation of China Major Research Plan on Nanomanufacturing(91323303)
文摘The sulfate ions modified YAG：Ce^（3＋） phosphors were prepared by co-precipitation method and characterized by X-ray diffraction,transmission electron microscopy,and photoluminescence.Effects of sulfate ions on the photoluminescence（PL） property of the as-prepared YAG：Ce^（3＋） phosphors were studied,with sodium dodecyl sulfate（SDS） being added to R^（3＋）（Ce^（3＋）,Y^（3＋）,Al^（3＋）） ions.Results indicated that pure YAG：Ce^（3＋） phosphors with different ratios of sulfate ions could be easily obtained by calcining the as-synthesized precursor at 950 ℃ for 2 h,the YAG：Ce^（3＋） phosphors with an optimal mass ratio of 3.5 wt.%SDS had the highest emission intensity and the best dispersion behavior,and the fluorescence decay of the as-obtained YAG：Ce^（3＋） phosphors was related to the lattice defect,reabsorption and cross correlation.Furthermore,thermal quenching properties of the YAG：Ce^（3＋） phosphors and the YAG：Ce^（3＋） phosphors with 3.5 wt.%SDS were also discussed,indicating that the YAG：Ce^（3＋） with SDS phosphors could have potential applications in the daylight LEDs or warm white LEDs.
