The Gd3+-doped TiO2 photocatalyst was prepared by the sol-gel and impregnation method. The effect of Gd3+ doping on crystalline size, BET surface area and photocatalytic activity was studied by XRD, FTIR, BET, UV-Vis ...The Gd3+-doped TiO2 photocatalyst was prepared by the sol-gel and impregnation method. The effect of Gd3+ doping on crystalline size, BET surface area and photocatalytic activity was studied by XRD, FTIR, BET, UV-Vis diffuse reflection spectroscopy, surface photovoltage spectroscopy (SPS). The activities of TiO2 and Gd3+-doped TiO2 catalysts for photocatalytic degradation of ethylene were studied by means of in situ FTIR. The photocatalytic reaction rate constant of ethylene becomes larger through Gd3+ doping. The rate constant of TiO2 was k1=8.51×10-4 min-1, while that of Gd/TiO2 was k2=1.85×10-3 min-1. At the same time, the yield of CO2 increased with Gd3+ doping. The enhancement in photocatalytic activity is probably due to the increase of light absorption, higher content of anatase, smaller crystal line size and higher specific surface area. In addition, the higher photocatalytic activity of Gd3+-doped TiO2 might be attributed to the effective separation of photo-generated electron-hole pairs.展开更多
【目的】基于聚合酶链式反应—变性梯度凝胶电泳(PCR-DGGE)对桑树根、茎、叶组织内生菌多样性的分析,结合浓度、纯度、PCR扩增性等指标,比较4种DNA提取方法之优劣。【方法】采用常见的DNA提取方法十六烷基三甲基溴化铵(CTAB)法、缓冲液...【目的】基于聚合酶链式反应—变性梯度凝胶电泳(PCR-DGGE)对桑树根、茎、叶组织内生菌多样性的分析,结合浓度、纯度、PCR扩增性等指标,比较4种DNA提取方法之优劣。【方法】采用常见的DNA提取方法十六烷基三甲基溴化铵(CTAB)法、缓冲液振荡(SPBS)法、液氮研磨(LNG)法和试剂盒(KIT)法提取桑树各组织DNA,从PCR-DGGE多样性等多方面对4种方法进行比较。【结果】对于桑树根和茎,DNA提取浓度最高的方法是LNG法,最低的是SPBS法;桑树叶情况则完全相反。桑树各组织,KIT法获得的DNA纯度均最高。桑树各组织通过16S r DNA PCR-DGGE比较内生细菌多样性,适宜的DNA提取方法是LNG法或CTAB法,不宜采用KIT法提取DNA。内生真菌ITS PCR-DGGE分析结果完全不同,最佳提取方法是KIT法,最不适宜的DNA提取方法因组织不同而异。【结论】对于桑树内生菌研究,最佳的DNA提取方法因组织不同而异,还与研究的内生菌种类有关系。展开更多
文摘The Gd3+-doped TiO2 photocatalyst was prepared by the sol-gel and impregnation method. The effect of Gd3+ doping on crystalline size, BET surface area and photocatalytic activity was studied by XRD, FTIR, BET, UV-Vis diffuse reflection spectroscopy, surface photovoltage spectroscopy (SPS). The activities of TiO2 and Gd3+-doped TiO2 catalysts for photocatalytic degradation of ethylene were studied by means of in situ FTIR. The photocatalytic reaction rate constant of ethylene becomes larger through Gd3+ doping. The rate constant of TiO2 was k1=8.51×10-4 min-1, while that of Gd/TiO2 was k2=1.85×10-3 min-1. At the same time, the yield of CO2 increased with Gd3+ doping. The enhancement in photocatalytic activity is probably due to the increase of light absorption, higher content of anatase, smaller crystal line size and higher specific surface area. In addition, the higher photocatalytic activity of Gd3+-doped TiO2 might be attributed to the effective separation of photo-generated electron-hole pairs.
文摘【目的】基于聚合酶链式反应—变性梯度凝胶电泳(PCR-DGGE)对桑树根、茎、叶组织内生菌多样性的分析,结合浓度、纯度、PCR扩增性等指标,比较4种DNA提取方法之优劣。【方法】采用常见的DNA提取方法十六烷基三甲基溴化铵(CTAB)法、缓冲液振荡(SPBS)法、液氮研磨(LNG)法和试剂盒(KIT)法提取桑树各组织DNA,从PCR-DGGE多样性等多方面对4种方法进行比较。【结果】对于桑树根和茎,DNA提取浓度最高的方法是LNG法,最低的是SPBS法;桑树叶情况则完全相反。桑树各组织,KIT法获得的DNA纯度均最高。桑树各组织通过16S r DNA PCR-DGGE比较内生细菌多样性,适宜的DNA提取方法是LNG法或CTAB法,不宜采用KIT法提取DNA。内生真菌ITS PCR-DGGE分析结果完全不同,最佳提取方法是KIT法,最不适宜的DNA提取方法因组织不同而异。【结论】对于桑树内生菌研究,最佳的DNA提取方法因组织不同而异,还与研究的内生菌种类有关系。
