Rice sheath blight pathogen,Rhizoctonia solani,produces numerous sclerotia to overwinter.As a rich source of nutrients in the soil,sclerotia may lead to the change of soil microbiota.For this purpose,we amended the sc...Rice sheath blight pathogen,Rhizoctonia solani,produces numerous sclerotia to overwinter.As a rich source of nutrients in the soil,sclerotia may lead to the change of soil microbiota.For this purpose,we amended the sclerotia of R.solani in soil and analyzed the changes in bacterial microbiota within the soil at different time points.At the phyla level,Proteobacteria,Acidobacteria,Bacteroidetes,Actinobacteria,Chloroflexi and Firmicutes showed varied abundance in the amended soil samples compared to those in the control.An increased abundance of ammonia-oxidizing bacterium(AOB)Nitrosospira and Nitrite oxidizing bacteria(NOB)i.e.,Nitrospira was observed,where the latter is reportedly involved in the nitrifier denitrification.Moreover,Thiobacillus,Gemmatimonas,Anaeromyxobacter and Geobacter,the vital players in denitrification,N2O reduction and reductive nitrogen transformation,respectively,depicted enhanced abundance in R.solani sclerotia-amended samples.Furthermore,asymbiotic nitrogen-fixing bacteria,notably,Azotobacter as well as Microvirga and Phenylobacterium with nitrogen-fixing potential also enriched in the amended samples compared to the control.Plant growth promoting bacteria,such as Kribbella,Chitinophaga and Flavisolibacter also enriched in the sclerotia-amended soil.As per our knowledge,this study is of its kind where pathogenic fungal sclerotia activated microbes with a potential role in N transformation and provided clues about the ecological functions of R.solani sclerotia on the stimulation of bacterial genera involved in different processes of N-cycle within the soil in the absence of host plants.展开更多
采用室内培养实验研究外加乳酸和蒽醌-2,6-磺酸钠等营养源条件下,玄武岩砖红壤中五氯酚的还原转化动力学与微生物群落结构变化。结果表明,玄武岩砖红壤中五氯酚的还原转化一级动力学常数为4.5×10 3d 1;添加乳酸或同时添加乳酸和AQ...采用室内培养实验研究外加乳酸和蒽醌-2,6-磺酸钠等营养源条件下,玄武岩砖红壤中五氯酚的还原转化动力学与微生物群落结构变化。结果表明,玄武岩砖红壤中五氯酚的还原转化一级动力学常数为4.5×10 3d 1;添加乳酸或同时添加乳酸和AQDS,五氯酚的还原转化速率显著提高,其一级动力学常数分别为7.3×10 3d 1和14.3×10 3d 1。循环伏安试测结果表明,添加乳酸和AQDS促进了砖红壤中活性亚铁的生成,并显著降低体系的氧化半反应峰电位。末端限制性片段长度多态性分析结果表明,添加五氯酚、乳酸和AQDS显著影响微生物群落结构,土壤微生物多样性显著下降;添加乳酸时,体系中微生物优势种群为梭菌,存在少量的具有铁还原能力的希瓦氏菌,未发现脱氯菌。因此,玄武岩砖红壤中五氯酚的还原转化主要是通过铁还原菌介导生成吸附态Fe(II)引起的活性亚铁还原脱氯机制。展开更多
An efficient method for preparation of substituted 1,2-phenylenedimethanols and aliphatic 1,4-diols that are valuable intermediates in organic synthesis, has been developed by the base-promoted reduction of isobenzofu...An efficient method for preparation of substituted 1,2-phenylenedimethanols and aliphatic 1,4-diols that are valuable intermediates in organic synthesis, has been developed by the base-promoted reduction of isobenzofuran-1(3H)-ones and y-lactones with silane under mild conditions. Compared with traditional procedures using stoichiometric amounts of metal hydrides and alkyl reductants, the present method avoids the use of sensitive reagents and is operationally simple and a broad variety of functional groups are tolerated.展开更多
制备了不同阳离子掺杂改性的针铁矿,并采用XRD、红外、热重差热分析以及TEM等手段对其进行了表征,结果显示,掺入Mn^(2+)、Cr^(3+)、Al^(3+)后并未明显改变α-FeOOH的晶体结构类型,说明部分阳离子掺杂进入α-FeOOH晶格,从而分别形成因Fe^...制备了不同阳离子掺杂改性的针铁矿,并采用XRD、红外、热重差热分析以及TEM等手段对其进行了表征,结果显示,掺入Mn^(2+)、Cr^(3+)、Al^(3+)后并未明显改变α-FeOOH的晶体结构类型,说明部分阳离子掺杂进入α-FeOOH晶格,从而分别形成因Fe^(3+)被Mn^(2+)、Cr^(3+)、Al^(3+)部分取代的固溶体;红外分析也得到类似结果;热重和差热分析以及TEM观察结果均表明几种金属阳离子没有形成氧化物相,可以确定这些离子已经进入针铁矿的晶格;紫外-可见漫反射光谱分析发现Mn^(2+)、Cr^(3+)掺杂者的能带隙较之纯相针铁矿的稍小,依次为2.18 e V和2.24 e V;而Al^(3+)掺杂者的能带隙与纯相针铁矿相比有所提高,增加至2.34 e V。此外还考查了不同阳离子掺杂及纯相针铁矿与Fe(Ⅱ)构成的复合系统对邻硝基苯酚(2-NP)的还原效果,研究表明,在溶液pH=6和25℃等的条件下,上述还原转化反应符合准一级动力学方程。其中,Fe(Ⅱ)/Al^(3+)掺杂针铁矿复合系统对2-NP的降解效果最好,在120 min时就达到了100%去除率,在一定浓度范围内,随着2-NP浓度的升高,2-NP的还原速率降低。而且,Fe(Ⅱ)/Al^(3+)-针铁矿复合系统速率常数(k)随着溶液的pH值增大而升高。展开更多
The reductive transformation of CO_2 to energy related products including formic acid, CO, formamide, methanol and methylamine could be a promising option to supply renewable energy. In this aspect, ruthenium has foun...The reductive transformation of CO_2 to energy related products including formic acid, CO, formamide, methanol and methylamine could be a promising option to supply renewable energy. In this aspect, ruthenium has found wide application in hydrogenation of various carbonyl groups, and has successfully been applied to reductive transformation of CO_2 with high catalytic efficiency and excellent selectivity. In addition, ruthenium complexes have also served as effective photosensitizers for CO_2 photoreduction.Classified by reductive products, this review summarizes and updates advances in the Ru-catalyzed reduction of CO_2 along with catalyst development on the basis of mechanistic understanding at a molecular level.展开更多
A new iron-fly ash packing was studied for reductive transformation of p-nitrotoluene. The packing was made of iron, fly ash and kaolin with the mass ratio of 36：7：2. A reactor was designed to investigate the long-t...A new iron-fly ash packing was studied for reductive transformation of p-nitrotoluene. The packing was made of iron, fly ash and kaolin with the mass ratio of 36：7：2. A reactor was designed to investigate the long-term performance of the packing. The results showed that the reduction of p-nitrotoluene increased with decreasing pH, because the reduction potential of reaction increased with the concentration of H＋. The pH was one of the key factors impacting the reductive transformation of p-nitrotoluene. Comparing iron-activated carbon packing with the new iron-fly ash packing, the reduction efficiencies were respectively 76.61% and 75.36% after20 days. The reduction efficiency for both was around 50% at 40 days. It was evident that these two kinds of packing had no significant difference in their capability for p-nitrotoluene reductive transformation. Compared with iron-activated carbon, the new iron-fly ash packing had obvious advantages in terms of manufacturing costs and environmental pollution degradation. This study showed that the new iron-fly ash packing had good performance in reductive transformation of nitrotoluene compounds.展开更多
文摘设施菜地由于污水灌溉、粪肥施用等导致重金属污染.本文通过土柱淹水同时添加玉米秸秆培养和后期通水淋洗,研究强还原法对设施土壤重金属(Cd、Cu、Pb和Zn)形态转化的影响.结果表明:强还原处理使土壤p H显著降低,玉米秸秆处理变化更显著;土壤氧化还原电位(Eh)迅速下降至-280 m V左右.玉米秸秆处理可以促进土壤中Cd、Cu、Pb和Zn活化,第9天土壤中有机物及硫化物结合态和残渣态Cd、Cu、Pb和Zn含量比重下降;至15 d培养结束,土壤中4种重金属含量较对照分别减少18.1%、19.0%、16.1%和15.7%.玉米秸秆处理可以增加土壤中Cd和Zn的溶出量,但是Cu的溶出量减少;胶体结合态Cd和Pb含量较对照增加、Cu较对照显著减少、Zn没有显著变化.强还原可以引起设施土壤重金属活化,提高蔬菜积累重金属的风险,而且其随土壤水分的运移可能导致水体的污染.
基金funded by the National Key R&D Program(grant number No.2017YFD0200600)and the earmarked fund for CARS-12.
文摘Rice sheath blight pathogen,Rhizoctonia solani,produces numerous sclerotia to overwinter.As a rich source of nutrients in the soil,sclerotia may lead to the change of soil microbiota.For this purpose,we amended the sclerotia of R.solani in soil and analyzed the changes in bacterial microbiota within the soil at different time points.At the phyla level,Proteobacteria,Acidobacteria,Bacteroidetes,Actinobacteria,Chloroflexi and Firmicutes showed varied abundance in the amended soil samples compared to those in the control.An increased abundance of ammonia-oxidizing bacterium(AOB)Nitrosospira and Nitrite oxidizing bacteria(NOB)i.e.,Nitrospira was observed,where the latter is reportedly involved in the nitrifier denitrification.Moreover,Thiobacillus,Gemmatimonas,Anaeromyxobacter and Geobacter,the vital players in denitrification,N2O reduction and reductive nitrogen transformation,respectively,depicted enhanced abundance in R.solani sclerotia-amended samples.Furthermore,asymbiotic nitrogen-fixing bacteria,notably,Azotobacter as well as Microvirga and Phenylobacterium with nitrogen-fixing potential also enriched in the amended samples compared to the control.Plant growth promoting bacteria,such as Kribbella,Chitinophaga and Flavisolibacter also enriched in the sclerotia-amended soil.As per our knowledge,this study is of its kind where pathogenic fungal sclerotia activated microbes with a potential role in N transformation and provided clues about the ecological functions of R.solani sclerotia on the stimulation of bacterial genera involved in different processes of N-cycle within the soil in the absence of host plants.
文摘采用室内培养实验研究外加乳酸和蒽醌-2,6-磺酸钠等营养源条件下,玄武岩砖红壤中五氯酚的还原转化动力学与微生物群落结构变化。结果表明,玄武岩砖红壤中五氯酚的还原转化一级动力学常数为4.5×10 3d 1;添加乳酸或同时添加乳酸和AQDS,五氯酚的还原转化速率显著提高,其一级动力学常数分别为7.3×10 3d 1和14.3×10 3d 1。循环伏安试测结果表明,添加乳酸和AQDS促进了砖红壤中活性亚铁的生成,并显著降低体系的氧化半反应峰电位。末端限制性片段长度多态性分析结果表明,添加五氯酚、乳酸和AQDS显著影响微生物群落结构,土壤微生物多样性显著下降;添加乳酸时,体系中微生物优势种群为梭菌,存在少量的具有铁还原能力的希瓦氏菌,未发现脱氯菌。因此,玄武岩砖红壤中五氯酚的还原转化主要是通过铁还原菌介导生成吸附态Fe(II)引起的活性亚铁还原脱氯机制。
基金the National Natural Science Foundation of China (Nos. 21572034, 21732007, 21871054) for financial support
文摘An efficient method for preparation of substituted 1,2-phenylenedimethanols and aliphatic 1,4-diols that are valuable intermediates in organic synthesis, has been developed by the base-promoted reduction of isobenzofuran-1(3H)-ones and y-lactones with silane under mild conditions. Compared with traditional procedures using stoichiometric amounts of metal hydrides and alkyl reductants, the present method avoids the use of sensitive reagents and is operationally simple and a broad variety of functional groups are tolerated.
文摘制备了不同阳离子掺杂改性的针铁矿,并采用XRD、红外、热重差热分析以及TEM等手段对其进行了表征,结果显示,掺入Mn^(2+)、Cr^(3+)、Al^(3+)后并未明显改变α-FeOOH的晶体结构类型,说明部分阳离子掺杂进入α-FeOOH晶格,从而分别形成因Fe^(3+)被Mn^(2+)、Cr^(3+)、Al^(3+)部分取代的固溶体;红外分析也得到类似结果;热重和差热分析以及TEM观察结果均表明几种金属阳离子没有形成氧化物相,可以确定这些离子已经进入针铁矿的晶格;紫外-可见漫反射光谱分析发现Mn^(2+)、Cr^(3+)掺杂者的能带隙较之纯相针铁矿的稍小,依次为2.18 e V和2.24 e V;而Al^(3+)掺杂者的能带隙与纯相针铁矿相比有所提高,增加至2.34 e V。此外还考查了不同阳离子掺杂及纯相针铁矿与Fe(Ⅱ)构成的复合系统对邻硝基苯酚(2-NP)的还原效果,研究表明,在溶液pH=6和25℃等的条件下,上述还原转化反应符合准一级动力学方程。其中,Fe(Ⅱ)/Al^(3+)掺杂针铁矿复合系统对2-NP的降解效果最好,在120 min时就达到了100%去除率,在一定浓度范围内,随着2-NP浓度的升高,2-NP的还原速率降低。而且,Fe(Ⅱ)/Al^(3+)-针铁矿复合系统速率常数(k)随着溶液的pH值增大而升高。
基金supported by the National Key Research and Development Program(2016YFA0602900)the National Natural Science Foundation of China(21472103,21672119)+2 种基金the Natural Science Foundation of Tianjin Municipality(16JCZDJC39900)Specialized Research Fund for the Doctoral Program of Higher Education(20130031110013)MOE Innovation Team(IRT13022)of China
文摘The reductive transformation of CO_2 to energy related products including formic acid, CO, formamide, methanol and methylamine could be a promising option to supply renewable energy. In this aspect, ruthenium has found wide application in hydrogenation of various carbonyl groups, and has successfully been applied to reductive transformation of CO_2 with high catalytic efficiency and excellent selectivity. In addition, ruthenium complexes have also served as effective photosensitizers for CO_2 photoreduction.Classified by reductive products, this review summarizes and updates advances in the Ru-catalyzed reduction of CO_2 along with catalyst development on the basis of mechanistic understanding at a molecular level.
基金supported by the National Key Scientific and Technology Project for Water Pollution Treatment of China (No. 2012ZX07202-002)
文摘A new iron-fly ash packing was studied for reductive transformation of p-nitrotoluene. The packing was made of iron, fly ash and kaolin with the mass ratio of 36：7：2. A reactor was designed to investigate the long-term performance of the packing. The results showed that the reduction of p-nitrotoluene increased with decreasing pH, because the reduction potential of reaction increased with the concentration of H＋. The pH was one of the key factors impacting the reductive transformation of p-nitrotoluene. Comparing iron-activated carbon packing with the new iron-fly ash packing, the reduction efficiencies were respectively 76.61% and 75.36% after20 days. The reduction efficiency for both was around 50% at 40 days. It was evident that these two kinds of packing had no significant difference in their capability for p-nitrotoluene reductive transformation. Compared with iron-activated carbon, the new iron-fly ash packing had obvious advantages in terms of manufacturing costs and environmental pollution degradation. This study showed that the new iron-fly ash packing had good performance in reductive transformation of nitrotoluene compounds.
