Peculiarities of a liquid phase hydrogenation, namely lower diffusivity of components influencing the reaction rate and deactivation of catalysts by leaching, are discussed. A focus is on hydrogenation of aromatic com...Peculiarities of a liquid phase hydrogenation, namely lower diffusivity of components influencing the reaction rate and deactivation of catalysts by leaching, are discussed. A focus is on hydrogenation of aromatic compounds, whereas the following processes are evaluated： （l） partial hydrogenation of benzene to cyclohexene; （2） hydrogenation of aniline; （3） hydrogenation of diphenylamine; （4） preparation of aniline from nitrobenzene; （5） hydrogenation of chloronitrobenzenes; （6） hydrogenation of 4-nitrosodiphenylamine and 4-nitrodiphenylamine mixture. Processes （1） and （6） are typically carried out in the water-oil system. Generally, this type of system allows reaching a higher selectivity to desired products. In the case of hydrogenation of 4-nitrosodiphenylamine and 4-nitrodiphenylamine mixture, the water phase extracts a water soluble catalyst; which is recycled and used for condensation of aniline and nitrobenzene. Problems of reaction kinetics, as well as catalysts deactivation are here discussed.展开更多
A menaquinone-7（MK-7） high-producing strain needs to be isolated to increase MK-7 production, in order to meet a requirement of MK-7 given the low MK-7 content in food products. This article focuses on developing MK...A menaquinone-7（MK-7） high-producing strain needs to be isolated to increase MK-7 production, in order to meet a requirement of MK-7 given the low MK-7 content in food products. This article focuses on developing MK-7 high-producing strains via screening and mutagenesis by an atmospheric and room temperature plasma（ARTP） mutation breeding system. We isolated an MK-7-producing strain Y-2 and identified it as Bacillus amyloliquefaciens, which produced（7.1±0.5） mg/L of MK-7 with maize meal hydrolysate as carbon source. Then, an MK-7 highproducing strain B. amyloliquefaciens H.β.D.R.-5 with resistance to 1-hydroxy-2-naphthoic acid, β-2-thienylalanine, and diphenylamine was obtained from the mutation of the strain Y-2 using an ARTP mutation breeding system. Using strain H.β.D.R.-5, efficient production of MK-7 was achieved（（30.2±2.7） mg/L）. In addition, the effects of nitrogen sources, prenyl alcohols, and MgSO_4 on MK-7 production were investigated, suggesting that soymeal extract combined with yeast extract, isopentenol, and MgSO4 was beneficial. Under the optimized condition, the MK-7 production and biomass-specific yield reached（61.3±5.2） mg/L and 2.59 mg/L per OD600 unit respectively in a 7-L fermenter. These results demonstrated that strain H.β.D.R.-5 has the capacity to produce MK-7 from maize meal hydrolysate, which could reduce the substrate cost.展开更多
文摘使用"假高稀"方法,分别以过硫酸铵、硝酸铁和三氯化铁为氧化剂,含有1个乙氧基基团的酸性磷酸酯为质子酸,经过原位聚合制备了直径分别为78～90 nm、18～30 nm和16～25 nm水分散性聚苯胺纳米线.聚苯胺膜的电导率分别为18,32和35 S cm-1,比表面积为65,70和82 m2g-1.该聚苯胺纳米线能够很好地分散在水中,是一种环境友好型超级电容器电极材料.该电极材料在1 mol L-1四乙基氟硼酸/碳酸丙烯酯非水性电解液中,在-1～1 V扫描范围内,以0.4 A g-1的放电速率下,分别得到了110,140和152 F g-1的比容,比电容与材料的比表面积和电导率有关,随着比表面积以及电导率的增大而增大.聚苯胺纳米线电极材料有较高的充放电效率(大于98%),表明了它们有很好的电化学可逆性.
文摘Peculiarities of a liquid phase hydrogenation, namely lower diffusivity of components influencing the reaction rate and deactivation of catalysts by leaching, are discussed. A focus is on hydrogenation of aromatic compounds, whereas the following processes are evaluated： （l） partial hydrogenation of benzene to cyclohexene; （2） hydrogenation of aniline; （3） hydrogenation of diphenylamine; （4） preparation of aniline from nitrobenzene; （5） hydrogenation of chloronitrobenzenes; （6） hydrogenation of 4-nitrosodiphenylamine and 4-nitrodiphenylamine mixture. Processes （1） and （6） are typically carried out in the water-oil system. Generally, this type of system allows reaching a higher selectivity to desired products. In the case of hydrogenation of 4-nitrosodiphenylamine and 4-nitrodiphenylamine mixture, the water phase extracts a water soluble catalyst; which is recycled and used for condensation of aniline and nitrobenzene. Problems of reaction kinetics, as well as catalysts deactivation are here discussed.
基金supported by the Natural Science Foundation of Jiangsu Province(No.BK20150149),China
文摘A menaquinone-7（MK-7） high-producing strain needs to be isolated to increase MK-7 production, in order to meet a requirement of MK-7 given the low MK-7 content in food products. This article focuses on developing MK-7 high-producing strains via screening and mutagenesis by an atmospheric and room temperature plasma（ARTP） mutation breeding system. We isolated an MK-7-producing strain Y-2 and identified it as Bacillus amyloliquefaciens, which produced（7.1±0.5） mg/L of MK-7 with maize meal hydrolysate as carbon source. Then, an MK-7 highproducing strain B. amyloliquefaciens H.β.D.R.-5 with resistance to 1-hydroxy-2-naphthoic acid, β-2-thienylalanine, and diphenylamine was obtained from the mutation of the strain Y-2 using an ARTP mutation breeding system. Using strain H.β.D.R.-5, efficient production of MK-7 was achieved（（30.2±2.7） mg/L）. In addition, the effects of nitrogen sources, prenyl alcohols, and MgSO_4 on MK-7 production were investigated, suggesting that soymeal extract combined with yeast extract, isopentenol, and MgSO4 was beneficial. Under the optimized condition, the MK-7 production and biomass-specific yield reached（61.3±5.2） mg/L and 2.59 mg/L per OD600 unit respectively in a 7-L fermenter. These results demonstrated that strain H.β.D.R.-5 has the capacity to produce MK-7 from maize meal hydrolysate, which could reduce the substrate cost.
