In this manuscript, a series of catalyst SG n-[VVO2-PAMAM-MSA] (SG silica gel, PAMAM polyamidoamine, MSA 5-methyl salicylaldehyde, n=0, 1, 2, 3) was prepared and their structures were fully characterized by Fourier tr...In this manuscript, a series of catalyst SG n-[VVO2-PAMAM-MSA] (SG silica gel, PAMAM polyamidoamine, MSA 5-methyl salicylaldehyde, n=0, 1, 2, 3) was prepared and their structures were fully characterized by Fourier transform-infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and inductive coupled plasma emission spectrometer (ICP) etc. XPS revealed that the metal V and SG n-PAMAM-MSA combined more closely after the formation of Schiff base derivatives. Their catalytic activities for oxidation of dibenzothiophene were evaluated using tert-butyl hydroperoxide as oxidant. The results showed that the catalyst SG 2.0-[VVO2-PAMAM-MSA] presented good catalytic activity and recycling time. Meanwhile, the optimal condition for the catalytic oxidation of SG 2.0-[VVO2-PAMAM-MSA] was also investigated, which showed that when the oxidation temperature was 90 °C, time was 60 min, the O/S was 3:1, and the mass content of catalyst was 1%, the rate of desulfurization could reach 85.2%. Moreover, the catalyst can be recycled several times without significant decline in catalytic activity.展开更多
The two-step nano-scale self-assembly technique and the framework structure mechanism for forming mesoporous supports were employed for preparing Al2O3-TiO2 complex supports with large pore volume that were applied fo...The two-step nano-scale self-assembly technique and the framework structure mechanism for forming mesoporous supports were employed for preparing Al2O3-TiO2 complex supports with large pore volume that were applied for manufacturing the resid hydrotreating catalysts. The influence of different TiO2 contents and calcination temperatures on specific surface area, pore volume and pore size distribution of complex supports was studied. TEM and SEM were employed to characterize the Al2O3-TiO2 complex supports. Test results revealed that the specific surface area of Al2O3-TiO2 complex supports was the largest at a TiO2 mass fraction of 20%, and when the calcination temperature was in the range between 300 ℃ to 700 ℃, the pore distribution of the complex support was stable. Characterization of the complex support by TEM and SEM demonstrated that TiO2 was homo- geneously distributed in the complex support, which was in favor of carrying active components. The Al2O3-TiO2 complex supports can function as the best catalyst support for resid hydrotreating catalysts.展开更多
The polystyrene supported phenylalanine Schiff base complex of Mn(Ⅱ) (PS-Sal-Phe-Mn ) was prepared with chloromethylated styrene polymer heads, 2 L-phenylalanine and manganese (Ⅱ) acetate tetrahyrate., The pol...The polystyrene supported phenylalanine Schiff base complex of Mn(Ⅱ) (PS-Sal-Phe-Mn ) was prepared with chloromethylated styrene polymer heads, 2 L-phenylalanine and manganese (Ⅱ) acetate tetrahyrate., The polymeric ligand and the complex were characterized by FT.IR,, small area X-ray photoelectron spectroscopy (XPS), and ICP-AES. in the presence of the manganese complex, cyclohexene (1) was effectively oxidized by molecular oxygen without reductant. The major products of the reaction were 2.cyclohexen-l-ol (2), 2-cyclohexen-l-one (3)and 2-cyclohexen-1-hydroperoxide (4), which was different with typical oxidation of cyclohexene. The influence of reaction temperature and additive for oxidation had been studied. The selectivity of 2-cyclohexen-l-hydroperoxide varied with reaction time and different additives. The mechanism of cyclohexene oxidation had also been discussed.展开更多
The polystyrene supported glutamic acid Schiff base complex of Mn ( Ⅱ ) (PS-Sal-Glue-Mn) was prepared with chloromethylated styrene polymer beads, 2,4-dihydroxybenzaldehyde, L-glutamic acid and manganese ( Ⅱ )...The polystyrene supported glutamic acid Schiff base complex of Mn ( Ⅱ ) (PS-Sal-Glue-Mn) was prepared with chloromethylated styrene polymer beads, 2,4-dihydroxybenzaldehyde, L-glutamic acid and manganese ( Ⅱ ) acetate tetrahyrate. The polymeric ligand and the complex were characterized by FT-IR, small area X-ray photoelectron spectroscopy (XPS) and 1CP-AES. In the presence of the manganese complex, cyclohexene (1) was effectively oxidized by molecular oxygen without reductant. The major products of the reaction were 2-cyclohexen-l-ol (2), 2-cyclohexen-l-one (3) and 2-cyclohexen-1- hydroperoxide (4), which was different with typical oxidation of cyclohexene. The influence of reaction temperature and additive for oxidation had been studied. The selectivity of 2-cyclohexen-1-hydroperoxide varied with reaction time and different additives. The mechanism of cyclohexene oxidation had also been discussed.展开更多
The main subject of the report consists in showing positive course of Russian agriculture over the last years-entering the global market. That's why it is essential to make following steps to support manufactures aim...The main subject of the report consists in showing positive course of Russian agriculture over the last years-entering the global market. That's why it is essential to make following steps to support manufactures aiming them more actively at export: to develop export operations; to develop actively agro-industrial complex perspectives for entering the WTO; to ensure the food safety of agro-industrial complex while exporting the products; in the context of globalization Russian regions are entering more actively the global market as the relatively independent subjects of international economical relationships. The food safety of Russia-such condition of the state economy, when food independence of the country is provided, provision; physical and economic utility of food products is guaranteed by the state and corresponds to requirements of the legislation of the Russian Federation in safety and quality. Participation in the WTO gives to the country set of advantages in the decision food independence. In the world, the country and in region management of efficiency agriculture with a view of advancement to food safety, should be coordinated necessarily with food independence. State support of the Russian agro-industrial complex on the federal and regional levels when entering into the world market-is a factor of the formation of a new geopolitical status of Russia in the world arena, it is the new selection mechanism of the development of globalization processes in favor of the active participation of the agro-industrial complex of Russia in the world economy.展开更多
To further clarify the proppant transport and placement law in multi-branched fractures induced by volume fracturing, proppant transport simulation experiments were performed with different fracture shapes, sand ratio...To further clarify the proppant transport and placement law in multi-branched fractures induced by volume fracturing, proppant transport simulation experiments were performed with different fracture shapes, sand ratios, branched fracture opening time and injection sequence of proppants in varied particle sizes. The results show that the settled proppant height increases and the placement length decreases in main fractures as the fracturing fluid diverts gradually to the branched fractures at different positions. The flow rate in branched fractures is the main factor affecting their filling. The diverion to branched fractures leads to low flow rate and poor filling of far-wellbore branched fractures. The inclined fracture wall exerts a frictional force on the proppant to slow its settlement, thus enhancing the vertical proppant distribution in the fracture. The increase of sand ratio can improve the filling of near-wellbore main fracture and far-wellbore branched fracture and also increase the settled proppant height in main fracture. Due to the limitation of fracture height, when the sand ratio increases to a certain level, the increment of fracture filling decreases. When branched fracture is always open(or extends continuously), the supporting effect on the branched fractures is the best, but the proppant placement length within the main fractures is shorter. The fractures support effect is better when it is first closed and then opened(or extends in late stage) than when it is first opened and then closed(or extends in early stage). Injecting proppants with different particle sizes in a specific sequence can improve the placement lengths of main fracture and branched fracture. Injection of proppants in an ascending order of particle size improves the near-wellbore fracture filling, to a better extent than that in a descending order of particle size.展开更多
A silica gel supported cobalt(lI) Schiff base complex was synthesized and used for the oxidation of alkyl aromatics using molecular oxygen as an oxidant under atmosphere pressure. The catalyst shows a high conversio...A silica gel supported cobalt(lI) Schiff base complex was synthesized and used for the oxidation of alkyl aromatics using molecular oxygen as an oxidant under atmosphere pressure. The catalyst shows a high conversion of alkyl aromatics and selectivity to benzylic ketones, and could be reused at least 5 times without significant loss of catalytic activity.展开更多
基金Supported by the National Natural Science Foundation of China (20901063) the Natural Science Foundation of Hubei Province (2011CDB221)
文摘In this manuscript, a series of catalyst SG n-[VVO2-PAMAM-MSA] (SG silica gel, PAMAM polyamidoamine, MSA 5-methyl salicylaldehyde, n=0, 1, 2, 3) was prepared and their structures were fully characterized by Fourier transform-infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and inductive coupled plasma emission spectrometer (ICP) etc. XPS revealed that the metal V and SG n-PAMAM-MSA combined more closely after the formation of Schiff base derivatives. Their catalytic activities for oxidation of dibenzothiophene were evaluated using tert-butyl hydroperoxide as oxidant. The results showed that the catalyst SG 2.0-[VVO2-PAMAM-MSA] presented good catalytic activity and recycling time. Meanwhile, the optimal condition for the catalytic oxidation of SG 2.0-[VVO2-PAMAM-MSA] was also investigated, which showed that when the oxidation temperature was 90 °C, time was 60 min, the O/S was 3:1, and the mass content of catalyst was 1%, the rate of desulfurization could reach 85.2%. Moreover, the catalyst can be recycled several times without significant decline in catalytic activity.
文摘The two-step nano-scale self-assembly technique and the framework structure mechanism for forming mesoporous supports were employed for preparing Al2O3-TiO2 complex supports with large pore volume that were applied for manufacturing the resid hydrotreating catalysts. The influence of different TiO2 contents and calcination temperatures on specific surface area, pore volume and pore size distribution of complex supports was studied. TEM and SEM were employed to characterize the Al2O3-TiO2 complex supports. Test results revealed that the specific surface area of Al2O3-TiO2 complex supports was the largest at a TiO2 mass fraction of 20%, and when the calcination temperature was in the range between 300 ℃ to 700 ℃, the pore distribution of the complex support was stable. Characterization of the complex support by TEM and SEM demonstrated that TiO2 was homo- geneously distributed in the complex support, which was in favor of carrying active components. The Al2O3-TiO2 complex supports can function as the best catalyst support for resid hydrotreating catalysts.
文摘The polystyrene supported phenylalanine Schiff base complex of Mn(Ⅱ) (PS-Sal-Phe-Mn ) was prepared with chloromethylated styrene polymer heads, 2 L-phenylalanine and manganese (Ⅱ) acetate tetrahyrate., The polymeric ligand and the complex were characterized by FT.IR,, small area X-ray photoelectron spectroscopy (XPS), and ICP-AES. in the presence of the manganese complex, cyclohexene (1) was effectively oxidized by molecular oxygen without reductant. The major products of the reaction were 2.cyclohexen-l-ol (2), 2-cyclohexen-l-one (3)and 2-cyclohexen-1-hydroperoxide (4), which was different with typical oxidation of cyclohexene. The influence of reaction temperature and additive for oxidation had been studied. The selectivity of 2-cyclohexen-l-hydroperoxide varied with reaction time and different additives. The mechanism of cyclohexene oxidation had also been discussed.
文摘The polystyrene supported glutamic acid Schiff base complex of Mn ( Ⅱ ) (PS-Sal-Glue-Mn) was prepared with chloromethylated styrene polymer beads, 2,4-dihydroxybenzaldehyde, L-glutamic acid and manganese ( Ⅱ ) acetate tetrahyrate. The polymeric ligand and the complex were characterized by FT-IR, small area X-ray photoelectron spectroscopy (XPS) and 1CP-AES. In the presence of the manganese complex, cyclohexene (1) was effectively oxidized by molecular oxygen without reductant. The major products of the reaction were 2-cyclohexen-l-ol (2), 2-cyclohexen-l-one (3) and 2-cyclohexen-1- hydroperoxide (4), which was different with typical oxidation of cyclohexene. The influence of reaction temperature and additive for oxidation had been studied. The selectivity of 2-cyclohexen-1-hydroperoxide varied with reaction time and different additives. The mechanism of cyclohexene oxidation had also been discussed.
文摘The main subject of the report consists in showing positive course of Russian agriculture over the last years-entering the global market. That's why it is essential to make following steps to support manufactures aiming them more actively at export: to develop export operations; to develop actively agro-industrial complex perspectives for entering the WTO; to ensure the food safety of agro-industrial complex while exporting the products; in the context of globalization Russian regions are entering more actively the global market as the relatively independent subjects of international economical relationships. The food safety of Russia-such condition of the state economy, when food independence of the country is provided, provision; physical and economic utility of food products is guaranteed by the state and corresponds to requirements of the legislation of the Russian Federation in safety and quality. Participation in the WTO gives to the country set of advantages in the decision food independence. In the world, the country and in region management of efficiency agriculture with a view of advancement to food safety, should be coordinated necessarily with food independence. State support of the Russian agro-industrial complex on the federal and regional levels when entering into the world market-is a factor of the formation of a new geopolitical status of Russia in the world arena, it is the new selection mechanism of the development of globalization processes in favor of the active participation of the agro-industrial complex of Russia in the world economy.
基金Supported by the National Natural Science Foundation of China (52074332,52204024)Outstanding Youth Foundation of Shandong Province (ZR2020YQ36)China Postdoctoral Science Foundation (M710225)。
文摘To further clarify the proppant transport and placement law in multi-branched fractures induced by volume fracturing, proppant transport simulation experiments were performed with different fracture shapes, sand ratios, branched fracture opening time and injection sequence of proppants in varied particle sizes. The results show that the settled proppant height increases and the placement length decreases in main fractures as the fracturing fluid diverts gradually to the branched fractures at different positions. The flow rate in branched fractures is the main factor affecting their filling. The diverion to branched fractures leads to low flow rate and poor filling of far-wellbore branched fractures. The inclined fracture wall exerts a frictional force on the proppant to slow its settlement, thus enhancing the vertical proppant distribution in the fracture. The increase of sand ratio can improve the filling of near-wellbore main fracture and far-wellbore branched fracture and also increase the settled proppant height in main fracture. Due to the limitation of fracture height, when the sand ratio increases to a certain level, the increment of fracture filling decreases. When branched fracture is always open(or extends continuously), the supporting effect on the branched fractures is the best, but the proppant placement length within the main fractures is shorter. The fractures support effect is better when it is first closed and then opened(or extends in late stage) than when it is first opened and then closed(or extends in early stage). Injecting proppants with different particle sizes in a specific sequence can improve the placement lengths of main fracture and branched fracture. Injection of proppants in an ascending order of particle size improves the near-wellbore fracture filling, to a better extent than that in a descending order of particle size.
基金the financial support from the National Natural Science Foundation of China–Academy of Engineering Physics(No.10976014)Natural Science Foundation of Jiangsu Province(No.BK2011697)
文摘A silica gel supported cobalt(lI) Schiff base complex was synthesized and used for the oxidation of alkyl aromatics using molecular oxygen as an oxidant under atmosphere pressure. The catalyst shows a high conversion of alkyl aromatics and selectivity to benzylic ketones, and could be reused at least 5 times without significant loss of catalytic activity.