An efficient stereoselective synthesis of the rigid aza-bicyclo[3.2.0]heptane scaffold has been developed to provide 2-cyano-pyrrolidine alpha-amino amide 1 as DPP-4 inhibitor.
Two new diaryheptanoids, (5S)-5-acetoxy-1,7-bis(4-hydroxy-3-methoxyphenyl)-3- heptanone (1) and (3S,5S)-3,5-diacetoxy-1,7-bis(4-hydroxy-3-methoxyphenyl)heptane (2) were isolated from the rhizomes of Zingiber officina...Two new diaryheptanoids, (5S)-5-acetoxy-1,7-bis(4-hydroxy-3-methoxyphenyl)-3- heptanone (1) and (3S,5S)-3,5-diacetoxy-1,7-bis(4-hydroxy-3-methoxyphenyl)heptane (2) were isolated from the rhizomes of Zingiber officinale. Their structures were elucidated by spectral methods.展开更多
The catalytic properties of MoOx and incorporation Ni onto the MoOx for the isomerization of heptane have been investigated under atmospheric pressure at different conditions such as different flow rate of H2, differe...The catalytic properties of MoOx and incorporation Ni onto the MoOx for the isomerization of heptane have been investigated under atmospheric pressure at different conditions such as different flow rate of H2, different reaction temperature etc.. Compared with MoOx, the Ni addition to the MoOx markedly improved the isomerization activity of heptane by improving the reducibility of MoO3 and activation of H2 in reaction.展开更多
FTIR method was used in this paper to investigate the structure of lysozyme in D2O solution and in microemulsions.It was found from the subtraction spectra that the Amide Ⅰband shifts to lower wavenumbers in microemu...FTIR method was used in this paper to investigate the structure of lysozyme in D2O solution and in microemulsions.It was found from the subtraction spectra that the Amide Ⅰband shifts to lower wavenumbers in microemulsions. The assignment of deconvoluted AmideⅠbund was given.The curve-fitting resulte show that the α-helix structure of lysozyme is reduced a lot in microemulsions.展开更多
The effects of CO2 on the partial oxidation of heptane for hydrogen generation have been studied. Based on the experimental results and thermodynamic equilibrium calculations, the validity of CO2 addition to weaken t...The effects of CO2 on the partial oxidation of heptane for hydrogen generation have been studied. Based on the experimental results and thermodynamic equilibrium calculations, the validity of CO2 addition to weaken the hot spots, and the feasibility of the autothermal operation are discussed.展开更多
The photocatalytic reaction of sulfur dioxide with heptane was carried out with the aid of UV illuminated titanium dioxide ultrafine particles(UFP) at room temperature. The TiO 2 UFP was prepared by means of colloid...The photocatalytic reaction of sulfur dioxide with heptane was carried out with the aid of UV illuminated titanium dioxide ultrafine particles(UFP) at room temperature. The TiO 2 UFP was prepared by means of colloidal chemical method. The structure and the surface state of the as prepared TiO 2 UFP via different heat treatments were studied. As the calcining temperature decreased, the contents of hydroxyl on the surface increased, which could help to enhance the photocatalytic activity of the TiO 2 UFP. The mechanism of the photocatalytic reaction of sulfur dioxide with heptane was proposed, in which there was a competition of photocatalytic oxidation between sulfur dioxide and heptane over the TiO 2 UFP. It is inferred that the reactive oxygen species play an important role in the photocatalytic reaction of sulfur dioxide with heptane.展开更多
Heptakis(2, 3, 6-tri-o-n-butyl)- β-cyclodextrin(TB- β-CD) has been found to form an inclusion compound with p-nitrophenol in heptane. The stability constent of the inclusion compound of p-nitrophenol with TB-β-CD i...Heptakis(2, 3, 6-tri-o-n-butyl)- β-cyclodextrin(TB- β-CD) has been found to form an inclusion compound with p-nitrophenol in heptane. The stability constent of the inclusion compound of p-nitrophenol with TB-β-CD in heptane is an order of magnitude greater than that in water.展开更多
The photochemical reaction of bicyclo[4.1.0]heptane was studied at the complete active space SCF（CASSCF） level with a 6-31G^＊ basis set. A muhireference MP2 algorithm that has been implemented in the Gaussian progr...The photochemical reaction of bicyclo[4.1.0]heptane was studied at the complete active space SCF（CASSCF） level with a 6-31G^＊ basis set. A muhireference MP2 algorithm that has been implemented in the Gaussian program was used to correct the energetics for the dynamic correlation. Starting from the Franck-Condon excitation of bicyclo [ 4.1.0 ] heptane, the reaction is via two bonds＇ breakage to give rise to 1,6-heptdiene. One internal conversion （IC） and two intersystem crossing points（ISC） were located and are discussed separately. The reaction proceeds to its own characteristic product on the ground state.展开更多
This work focuses on blending Jatropha oil with diesel fuel and heptane to improve its physico-chemical characteristics for production of blends and their use as fuel in a diesel engine. The influence of the heptane c...This work focuses on blending Jatropha oil with diesel fuel and heptane to improve its physico-chemical characteristics for production of blends and their use as fuel in a diesel engine. The influence of the heptane content was evaluated by comparing the results obtained from the engine (performance and combustion parameters) with those of the diesel fuel and straight Jatropha oil. The results obtained show an improvement in engine performance especially at low loads. Specifically, a reduction in the specific fuel consumption of the engine is obtained when the heptane content in the mixture is around 10% compared to that obtained with pure Jatropha oil. The best results were obtained with the blend containing 70% Jatropha oil, 20% diesel fuel and 10% heptane (J70G20H10). Overall engine efficiency and exhaust gas temperatures are comparable for all fuels tested. Engine combustion parameters are improved with J70G20H10. The results obtained with J70G20H10 are close to those of the engine operating on diesel fuel. The cyclic dispersion is low with coefficients of variation of the indicated mean effective pressure (COV<sub>IMEP</sub>) whose values are less than 10%. The lowest values of the COV<sub>IMEP</sub> are obtained with the blend J70G20H10.展开更多
文摘An efficient stereoselective synthesis of the rigid aza-bicyclo[3.2.0]heptane scaffold has been developed to provide 2-cyano-pyrrolidine alpha-amino amide 1 as DPP-4 inhibitor.
文摘Two new diaryheptanoids, (5S)-5-acetoxy-1,7-bis(4-hydroxy-3-methoxyphenyl)-3- heptanone (1) and (3S,5S)-3,5-diacetoxy-1,7-bis(4-hydroxy-3-methoxyphenyl)heptane (2) were isolated from the rhizomes of Zingiber officinale. Their structures were elucidated by spectral methods.
文摘The catalytic properties of MoOx and incorporation Ni onto the MoOx for the isomerization of heptane have been investigated under atmospheric pressure at different conditions such as different flow rate of H2, different reaction temperature etc.. Compared with MoOx, the Ni addition to the MoOx markedly improved the isomerization activity of heptane by improving the reducibility of MoO3 and activation of H2 in reaction.
文摘FTIR method was used in this paper to investigate the structure of lysozyme in D2O solution and in microemulsions.It was found from the subtraction spectra that the Amide Ⅰband shifts to lower wavenumbers in microemulsions. The assignment of deconvoluted AmideⅠbund was given.The curve-fitting resulte show that the α-helix structure of lysozyme is reduced a lot in microemulsions.
文摘The effects of CO2 on the partial oxidation of heptane for hydrogen generation have been studied. Based on the experimental results and thermodynamic equilibrium calculations, the validity of CO2 addition to weaken the hot spots, and the feasibility of the autothermal operation are discussed.
基金Supported by the National Natural Science Foundation of China.
文摘The photocatalytic reaction of sulfur dioxide with heptane was carried out with the aid of UV illuminated titanium dioxide ultrafine particles(UFP) at room temperature. The TiO 2 UFP was prepared by means of colloidal chemical method. The structure and the surface state of the as prepared TiO 2 UFP via different heat treatments were studied. As the calcining temperature decreased, the contents of hydroxyl on the surface increased, which could help to enhance the photocatalytic activity of the TiO 2 UFP. The mechanism of the photocatalytic reaction of sulfur dioxide with heptane was proposed, in which there was a competition of photocatalytic oxidation between sulfur dioxide and heptane over the TiO 2 UFP. It is inferred that the reactive oxygen species play an important role in the photocatalytic reaction of sulfur dioxide with heptane.
文摘Heptakis(2, 3, 6-tri-o-n-butyl)- β-cyclodextrin(TB- β-CD) has been found to form an inclusion compound with p-nitrophenol in heptane. The stability constent of the inclusion compound of p-nitrophenol with TB-β-CD in heptane is an order of magnitude greater than that in water.
基金Supported by the Yunnan Provincial Science and Technology Department(No. 2003A0003M)
文摘The photochemical reaction of bicyclo[4.1.0]heptane was studied at the complete active space SCF（CASSCF） level with a 6-31G^＊ basis set. A muhireference MP2 algorithm that has been implemented in the Gaussian program was used to correct the energetics for the dynamic correlation. Starting from the Franck-Condon excitation of bicyclo [ 4.1.0 ] heptane, the reaction is via two bonds＇ breakage to give rise to 1,6-heptdiene. One internal conversion （IC） and two intersystem crossing points（ISC） were located and are discussed separately. The reaction proceeds to its own characteristic product on the ground state.
文摘This work focuses on blending Jatropha oil with diesel fuel and heptane to improve its physico-chemical characteristics for production of blends and their use as fuel in a diesel engine. The influence of the heptane content was evaluated by comparing the results obtained from the engine (performance and combustion parameters) with those of the diesel fuel and straight Jatropha oil. The results obtained show an improvement in engine performance especially at low loads. Specifically, a reduction in the specific fuel consumption of the engine is obtained when the heptane content in the mixture is around 10% compared to that obtained with pure Jatropha oil. The best results were obtained with the blend containing 70% Jatropha oil, 20% diesel fuel and 10% heptane (J70G20H10). Overall engine efficiency and exhaust gas temperatures are comparable for all fuels tested. Engine combustion parameters are improved with J70G20H10. The results obtained with J70G20H10 are close to those of the engine operating on diesel fuel. The cyclic dispersion is low with coefficients of variation of the indicated mean effective pressure (COV<sub>IMEP</sub>) whose values are less than 10%. The lowest values of the COV<sub>IMEP</sub> are obtained with the blend J70G20H10.
