Individual hydrocarbons identified to be macrocyclic alkanes in a torbanite from the Sydney Basin(Australia)were successfully isolated from its extracts using preparative gas chromatography and analyzed by NMR.Saturat...Individual hydrocarbons identified to be macrocyclic alkanes in a torbanite from the Sydney Basin(Australia)were successfully isolated from its extracts using preparative gas chromatography and analyzed by NMR.Saturated cyclic structures were confirmed by single peaks in the NMR~1H and~(13)C spectra indicating single forms of H and C atoms exist in these biomarker molecules.This is consistent with the methylene unit in a ring system assignment of the macrocyclic alkanes and accounts for a formula of(CH2)n.The unusual molecular structures of these compounds are consistent with those that were identified from previous GC retention index data and co-injection with a standard supports the previous research.The mass spectral fragmentation behaviors of representative cyclic alkanes were further investigated by comparing them with the mass spectra of isolated individual macrocyclic alkanes.The characteristic fragment ions in the macrocyclic alkanes of(M–28)+and base peaks of m/z 97,111,125,etc.,can be assigned as being generated by simple a-/i-cleavage and hydrogen rearrangement.These fragmentation pathways combined with retention indices should assist in differentiating these compounds from monounsaturated alkenes and alkylated monocyclics having similar mass spectral characteristics in other geological samples.展开更多
Mitigation of the deleterious environmental impacts associated with CO_(2) emissions requires the development of more sustainable processes for synthesizing fuels and chemicals.Selective conversion of abundant yet dif...Mitigation of the deleterious environmental impacts associated with CO_(2) emissions requires the development of more sustainable processes for synthesizing fuels and chemicals.Selective conversion of abundant yet difficult to activate molecules such as CO_(2) and surplus light alkanes from shale gas to desirable products can potentially reduce reliance upon conventional fossil-based feedstocks.Therefore,co-conversion of CO_(2) with abundant light alkanes such as methane and ethane using atmospheric-pressure.展开更多
A series of Monomethyl branched alkanes compounds were detected between nC14-nC36,in immature and low maturity Jurassic humic coal,Junggar basin.2-methyl alkanes and 3-methyl alkanes accounted for the vast majority of...A series of Monomethyl branched alkanes compounds were detected between nC14-nC36,in immature and low maturity Jurassic humic coal,Junggar basin.2-methyl alkanes and 3-methyl alkanes accounted for the vast majority of the compounds.It is worth noting that the2-methyl alkanes in the humic coal samples show an obvious distribution of even carbon predominances rarely reported in the literature.The results show that with the increase of Pr/Ph(pristane/phytane),the even carbon dominance of 2-methyl alkanes is more obvious,while the odd carbon number distribution of 3-methyl alkanes is weakened.As Pr/Ph increases in the humic coal,the relative content of the hopanes increased,while the relative content of 2-methyl alkanes and 3-methyl alkanes increases first and then decreases.展开更多
Solvent effect on the conformations of-bis（4-nitrophenoxy）-alkanesw th different chain Lengths（Nn）was studied by UV spectra.In poor solvents such asEG-H<sub>2</sub>O and THF-H<sub>2</sub>O,...Solvent effect on the conformations of-bis（4-nitrophenoxy）-alkanesw th different chain Lengths（Nn）was studied by UV spectra.In poor solvents such asEG-H<sub>2</sub>O and THF-H<sub>2</sub>O,with the water content higher than 50%,the K-bands of N<sub>4</sub>.N,N<sub>6</sub> and N<sub>10</sub>in the UV absorption spectra shifted to longer wavelengths as comparedwth 4-nitrophenoxyethane（N<sub>0</sub>）.It is suggested that in poor solvents the two aromaticgrps are close to each other in parallel,forming ground state complexes.The K-bead of N<sub>4</sub> showed a blue shift from that of N<sub>0</sub> when the water content was around5%,probably attributable to a conformation with the nitro group of one benzene ringsiting on the plane of the other benzene ring.展开更多
China University of Petroleum(East China)has developed an inexpensive and environmentally friendly TiO2 catalyst for dehydrogenation of low-carbon alkanes,which is an excellent substitute for the Pt series catalysts(w...China University of Petroleum(East China)has developed an inexpensive and environmentally friendly TiO2 catalyst for dehydrogenation of low-carbon alkanes,which is an excellent substitute for the Pt series catalysts(with high production cost)and Cr series catalysts(with toxicity)coupled with apparent technical and economic benefits and high applicability.展开更多
In a new study,published on Nature Communications,scientists led by Prof.TONG Peng at the Institute of Solid State Physics,Hefei Institutes of Physical Science(HFIPS),Chinese Academy of Sciences(CAS),described how the...In a new study,published on Nature Communications,scientists led by Prof.TONG Peng at the Institute of Solid State Physics,Hefei Institutes of Physical Science(HFIPS),Chinese Academy of Sciences(CAS),described how they discovered excellent BC cooling performance in n-alkanes with self-developed barocaloric(BC)test platform,providing a new perspective for developing the application-oriented green refrigeration technology.展开更多
Spray auto-ignition experiments were carried out in a constant volume combustion chamber for some pure alkanes(n-paraffins with different chain length, cyclohexane, n-butyl cyclohexane, and isooctane) and blends of n-...Spray auto-ignition experiments were carried out in a constant volume combustion chamber for some pure alkanes(n-paraffins with different chain length, cyclohexane, n-butyl cyclohexane, and isooctane) and blends of n-decane with Standard Blended Fuel(isooctane/n-heptane) and product gasoline. Test results showed that the reaction activity of n-paraffins was relatively high. Meanwhile, the auto-ignition characteristics differed significantly with the molecular structures of alkanes. Adding different volume fractions of n-decane to Standard Blended Fuel and product gasoline could improve the fuel reaction activity at varying degree. Finally, functional groups effects were used to simulate the relationship between the molecular topology and the auto-ignition quality.展开更多
This review paper aims at analysing the state of the art for partial oxidation and oxidative dehydrogenation(ODH) reactions of lower alkanes C_1–C_6into olefins and oxygenated products(aldehydes, anhydrides,carboxyli...This review paper aims at analysing the state of the art for partial oxidation and oxidative dehydrogenation(ODH) reactions of lower alkanes C_1–C_6into olefins and oxygenated products(aldehydes, anhydrides,carboxylic acids) on metal oxide catalysts with cations of variable oxidation state, such as Mo and V in particular. Key parameters to be met by the catalysts, such as their redox properties, their structural aspects, active sites composed of ensembles of atoms isolated one from the others, mechanisms of reactions, are discussed. Main features of the different reactions of C_1–C_6alkanes and catalysts are analysed and their generalisation for determining more active and more selective catalysts is attempted. Prospective views for the future of the domain are proposed.展开更多
The authors studied the biomarkers (alkanes) of eight iron ore samples from Nianpanshan and Dsbaodui of Pangjiabao and Longguan, Xuanhua, Hebei. These samples have higher nC15-nC20 contents, with main peaks at nC16, n...The authors studied the biomarkers (alkanes) of eight iron ore samples from Nianpanshan and Dsbaodui of Pangjiabao and Longguan, Xuanhua, Hebei. These samples have higher nC15-nC20 contents, with main peaks at nC16, nC 17 and nC18, and contain abundant pristane and phytane. These results indicate that iron stromatolite and iron oncolites in orebodies are sedimentary structures of algal origin. Sedimentary iron accumulation mainly results from activity of blue algae. This study provides new valuable evidence for the origin of Xuanlong-type iron deposits.展开更多
1 INTRODUCTIONAfter Prausnitz et al.published the perturbed hard-sphere chain theory(PHCT),manymodified theories have been put forward,such as the perturbed soft-sphere chain theory(PSCT),the perturbed anisotropic cha...1 INTRODUCTIONAfter Prausnitz et al.published the perturbed hard-sphere chain theory(PHCT),manymodified theories have been put forward,such as the perturbed soft-sphere chain theory(PSCT),the perturbed anisotropic chain theory(PACT)and the associated perturbedanisotropic chain theory(APACT).These theories are all concerned with the parameter3c.But,Wertheim in his work proved that the free energy of hard-sphere chain couldbe calculated without 3c.Induced by the work done by Wertheim,Chapman展开更多
A novel topological index derived from eccentric connectivity index bas been proposed. The new topological index and eccentric connectivity index were correlated with eight physical properties such as the boiling poin...A novel topological index derived from eccentric connectivity index bas been proposed. The new topological index and eccentric connectivity index were correlated with eight physical properties such as the boiling point, critical temperature, critical pressure, critical volume, evaporation heat, density, heat capaci- ty, surface tension, and three thermodynamic properties suck as standard enthalpy, standard entropy and standard formation free energy or alkanes. A series of empiric equations for calculating the properties were obtaines. Correlation coefficients or nine properties were more than 0. 99. Regression analysis and calcula- tion results indicated that the topological indices were well correlated with the physico-chemical properties or alkanes, and the novel topological index was far superior to eccentric connectivity index in the correlation.展开更多
Investigating the development toxicity of perfuorinated iodine alkanes(PFIs)is critical,given their estrogenic effects through binding with estrogen receptors(ERs).In the present study,two PFIs,including dodecafuoro-1...Investigating the development toxicity of perfuorinated iodine alkanes(PFIs)is critical,given their estrogenic effects through binding with estrogen receptors(ERs).In the present study,two PFIs,including dodecafuoro-1,6-diiodohexane(PFHx DI)and tridecafuorohexyl iodide(PFHx I),with binding preference to ERαand ERβ,respectively,were selected to evaluate their effects on proliferation and differentiation of the mouse embryonic stem cells(m ESCs).The results revealed that,similar to E_(2),50μmol/L PFHx DI accelerated the cell proliferation of the m ESCs.The PFI stimulation at the exposure concentrations of 2–50μmol/L promoted the differentiation of the m ESCs as characterized by the upregulation of differentiation-related biomarkers(i.e.,Otx2 and Dnmt3β)and downregulation of pluripotency genes(i.e.,Oct4,Nanog,Sox2,Prdm14 and Rex1).Comparatively,PFHx DI exhibited higher induction effect on the differentiation of the m ESCs than did PFHx I.The tests on ER signaling indicated that both PFI compounds induced exposure concentration-dependent expressions of ER signaling-related biomarkers(i.e.,ERα,ERβand Caveolin-1)in the m ESCs,and the downstream ER responsive genes(i.e.,c-fos,c-myc and c-jun)well responded to PFHx I stimulation.The role of ER in PFI-induced effects on the m ESCs was further validated by the antagonistic experiments using an ER inhibitor(ICI).The findings demonstrated that PFIs triggered ER signaling,and perturbed the differentiation program of the m ESCs,causing the potential health risk during early stage of development.展开更多
A simple,practical and eco-friendly visible light-induced alkylation of N-sulfonyl ketamine under metal-,additive-,external photocatalyst-free conditions was developed.This photocatalytic method utilized low cost and ...A simple,practical and eco-friendly visible light-induced alkylation of N-sulfonyl ketamine under metal-,additive-,external photocatalyst-free conditions was developed.This photocatalytic method utilized low cost and abundant alkanes as the atom economy alkyl sources with H2O2as the environmentally beneficial oxidant,allowing for the efficient construction of diverse valuable 4-alkylated sulfonyl ketamines.The N-sulfonyl ketamine played a dual role of reactant and photocatalyst,thus simplifying the reaction system.展开更多
An electrostatic bond energy model is formulated to fit the enthalpies of formation and dipole moments of the alkanes and chloroalkanes. In this model, the charge distributions are calculated by an electrostatic appro...An electrostatic bond energy model is formulated to fit the enthalpies of formation and dipole moments of the alkanes and chloroalkanes. In this model, the charge distributions are calculated by an electrostatic approach similar to the "MSE" method, and the enthalpy of formation of a molecule is the sum of the bond energy terms plus the electrostatic energy of the interactions between the charges on all atoms. All parameters of this model are obtained by parameterization. The calculated dipole moments for 13 chloroalkanes and enthalpies of formation for 19 alkanes and non-geminal chloroalkanes agree with the determined values very well. To calculate the enthalpies of formation of geminal chloroalkanes, a correction mainly attributed to the van der Waals interactions in the geminal substituted group, about 24 kJ/mol per pair of geminal chlorine atoms, is introduced.展开更多
A rather satisfactory method of synthesis of aldoximes and ketoximes by direct nitrosation of alkanes and an adequate technique of separating the mixtures and identifying the components from the reactions were worked ...A rather satisfactory method of synthesis of aldoximes and ketoximes by direct nitrosation of alkanes and an adequate technique of separating the mixtures and identifying the components from the reactions were worked out.By these procedures, the nitrosation of pentane, hexane and heptane gave different results from those reported in literature, and the study on octane was new.展开更多
CO adsorption microcalorimetry was employed in the study of γ-Al-2O-3-supported Pt, Pt-Sn and Pt-Fe catalysts. The results indicated that the initial differential heat of CO adsorption of the Pt/γ-Al-2O-3 catalyst w...CO adsorption microcalorimetry was employed in the study of γ-Al-2O-3-supported Pt, Pt-Sn and Pt-Fe catalysts. The results indicated that the initial differential heat of CO adsorption of the Pt/γ-Al-2O-3 catalyst was 125 kJ/mol. As CO coverage increased, the differential heat of adsorption decreased. At higher coverages, the differential heat of adsorption decreased significantly. 60% of the differential heat of CO adsorption on the Pt/γ-Al-2O-3 catalyst was higher than 100 kJ/mol. No significant effect on the initial differential heat was found after adding Sn and Fe to the Pt/γ-Al-2O-3 catalyst. The amount of strong CO adsorption sites decreased, while the portion of CO adsorption sites with differential heat of 60110 kJ/mol increased after increasing the Sn or Fe content. This indicates that the surface adsorption energy was changed by adding Sn or Fe to Pt/γ-Al-2O-3. The distribution of differential heat of CO adsorption on the Pt-Sn（C）/γ-Al-2O-3 catalyst was broad and homogeneous. Comparison of the dehydrogenation performance of C-4 alkanes with the number of CO adsorption sites with differential heat of 60110 kJ/mol showed a good correlation. These results indicate that the surface Pt centers with differential heats of 60110 kJ/mol for CO adsorption possess superior activity for the dehydrogenation of alkanes.展开更多
Absolute concentration of normal alkanes(n-alkanes) and aromatic hydrocarbons in bitumen extracted from source rocks in the period of thermodegradation from Turpan-Hami Basin suggests that aromatic hydrocarbons are do...Absolute concentration of normal alkanes(n-alkanes) and aromatic hydrocarbons in bitumen extracted from source rocks in the period of thermodegradation from Turpan-Hami Basin suggests that aromatic hydrocarbons are dominant in coal and carbargilite while n-alkanes are dominant in mudstones. Bulkrock analysis and gas chromatograph/mass spectrum(GC-MS) of source rocks shows aromatic hydrocarbons are dominant in total ion chromatograms(TIC) of samples with poor perhydrous macerals while n-alkanes are dominant in TICs of samples with abundant perhydrous macerals. The identification of oil-prone and gas prone property based on GC-MS of bitumen "A" together with bulkrock analysis indicates that source rocks from Shengbei area are more oil-prone while source rocks from Qiudong and Xiaocaohu areas are more gas-prone,coinciding with the distribution of oil and gas reservoirs in Taibei Sag. Ratios used to identify oil-prone and gas-prone property for source rocks from Turpan Basin are proposed:n-alkanes >110 μg·mg-1,aromatics <15 μg·mg-1,and n-alkanes/aromatics >8 for oil-prone source rock bitumen while n-alkanes<82 μg·mg-1,aromatics >40 μg·mg-1,and n-alkanes/aromatics <1.5 for gas-prone source rock bitumen.展开更多
A series of NCP-type pincer iridium complexes,(RNCCp)IrHCl(2a-2c)and(BQ-NCOP)IrHCl 3,have been studied for catalytic transfer alkane dehydrogenation.Complex 3 containing a rigid benzoquinoline backbone exhibits high a...A series of NCP-type pincer iridium complexes,(RNCCp)IrHCl(2a-2c)and(BQ-NCOP)IrHCl 3,have been studied for catalytic transfer alkane dehydrogenation.Complex 3 containing a rigid benzoquinoline backbone exhibits high activity and robustness in dehydrogenation of alkanes to form alkenes.Even more importantly,this catalyst system was also highly effective in the dehydrogenation of a wide range of heterocycles to furnish heteroarenes.展开更多
Ⅰ. INTRODUCTION The oxidation of saturated hydrocarbons Was, in the past, concentrated in the oxidation of paraffin into mixed fatty acids, which were then used in industry in soapmaking, etc. Simple gaseous hydrocar...Ⅰ. INTRODUCTION The oxidation of saturated hydrocarbons Was, in the past, concentrated in the oxidation of paraffin into mixed fatty acids, which were then used in industry in soapmaking, etc. Simple gaseous hydrocarbons, such as from methane and ethane were also used as subjects in the kinetical study of oxidation reactions. Reports of work focusing on the studies of synthesis of oxygen derivatives directly from oxidation of single alkane were few.展开更多
Because of their inertmess toward chemical reagents, the chemistry of alkanes is rather poorly developed. The chlorination of alkanes was formerly done on mixtures such as paraffins and petroleum oils, the aim of whic...Because of their inertmess toward chemical reagents, the chemistry of alkanes is rather poorly developed. The chlorination of alkanes was formerly done on mixtures such as paraffins and petroleum oils, the aim of which was to obtain solvents or their further hydrolytic products-alcohols, for technical uses. Reports on the study of the rules for the chlori-展开更多
基金the financial support from The Strategic Priority Research Program of the Chinese Academy of Sciences(XDA14010102)Chinese National Science Foundation grants(4197306941673045)。
文摘Individual hydrocarbons identified to be macrocyclic alkanes in a torbanite from the Sydney Basin(Australia)were successfully isolated from its extracts using preparative gas chromatography and analyzed by NMR.Saturated cyclic structures were confirmed by single peaks in the NMR~1H and~(13)C spectra indicating single forms of H and C atoms exist in these biomarker molecules.This is consistent with the methylene unit in a ring system assignment of the macrocyclic alkanes and accounts for a formula of(CH2)n.The unusual molecular structures of these compounds are consistent with those that were identified from previous GC retention index data and co-injection with a standard supports the previous research.The mass spectral fragmentation behaviors of representative cyclic alkanes were further investigated by comparing them with the mass spectra of isolated individual macrocyclic alkanes.The characteristic fragment ions in the macrocyclic alkanes of(M–28)+and base peaks of m/z 97,111,125,etc.,can be assigned as being generated by simple a-/i-cleavage and hydrogen rearrangement.These fragmentation pathways combined with retention indices should assist in differentiating these compounds from monounsaturated alkenes and alkylated monocyclics having similar mass spectral characteristics in other geological samples.
基金financially supported by the Yale Center for Natural Carbon Capturesupport from the U.S. Department of Energy, Office of Basic Energy Sciences, under Contract No. DE-SC0012704。
文摘Mitigation of the deleterious environmental impacts associated with CO_(2) emissions requires the development of more sustainable processes for synthesizing fuels and chemicals.Selective conversion of abundant yet difficult to activate molecules such as CO_(2) and surplus light alkanes from shale gas to desirable products can potentially reduce reliance upon conventional fossil-based feedstocks.Therefore,co-conversion of CO_(2) with abundant light alkanes such as methane and ethane using atmospheric-pressure.
基金This research was financially supported by the National Natural Science Foundation of China(No.41772124)National Science and Technology Major Project(No.2016ZX05007001-002).
文摘A series of Monomethyl branched alkanes compounds were detected between nC14-nC36,in immature and low maturity Jurassic humic coal,Junggar basin.2-methyl alkanes and 3-methyl alkanes accounted for the vast majority of the compounds.It is worth noting that the2-methyl alkanes in the humic coal samples show an obvious distribution of even carbon predominances rarely reported in the literature.The results show that with the increase of Pr/Ph(pristane/phytane),the even carbon dominance of 2-methyl alkanes is more obvious,while the odd carbon number distribution of 3-methyl alkanes is weakened.As Pr/Ph increases in the humic coal,the relative content of the hopanes increased,while the relative content of 2-methyl alkanes and 3-methyl alkanes increases first and then decreases.
文摘Solvent effect on the conformations of-bis（4-nitrophenoxy）-alkanesw th different chain Lengths（Nn）was studied by UV spectra.In poor solvents such asEG-H<sub>2</sub>O and THF-H<sub>2</sub>O,with the water content higher than 50%,the K-bands of N<sub>4</sub>.N,N<sub>6</sub> and N<sub>10</sub>in the UV absorption spectra shifted to longer wavelengths as comparedwth 4-nitrophenoxyethane（N<sub>0</sub>）.It is suggested that in poor solvents the two aromaticgrps are close to each other in parallel,forming ground state complexes.The K-bead of N<sub>4</sub> showed a blue shift from that of N<sub>0</sub> when the water content was around5%,probably attributable to a conformation with the nitro group of one benzene ringsiting on the plane of the other benzene ring.
文摘China University of Petroleum(East China)has developed an inexpensive and environmentally friendly TiO2 catalyst for dehydrogenation of low-carbon alkanes,which is an excellent substitute for the Pt series catalysts(with high production cost)and Cr series catalysts(with toxicity)coupled with apparent technical and economic benefits and high applicability.
文摘In a new study,published on Nature Communications,scientists led by Prof.TONG Peng at the Institute of Solid State Physics,Hefei Institutes of Physical Science(HFIPS),Chinese Academy of Sciences(CAS),described how they discovered excellent BC cooling performance in n-alkanes with self-developed barocaloric(BC)test platform,providing a new perspective for developing the application-oriented green refrigeration technology.
基金funded by the National Key Research and Development Program (2017YFB0306505)
文摘Spray auto-ignition experiments were carried out in a constant volume combustion chamber for some pure alkanes(n-paraffins with different chain length, cyclohexane, n-butyl cyclohexane, and isooctane) and blends of n-decane with Standard Blended Fuel(isooctane/n-heptane) and product gasoline. Test results showed that the reaction activity of n-paraffins was relatively high. Meanwhile, the auto-ignition characteristics differed significantly with the molecular structures of alkanes. Adding different volume fractions of n-decane to Standard Blended Fuel and product gasoline could improve the fuel reaction activity at varying degree. Finally, functional groups effects were used to simulate the relationship between the molecular topology and the auto-ignition quality.
文摘This review paper aims at analysing the state of the art for partial oxidation and oxidative dehydrogenation(ODH) reactions of lower alkanes C_1–C_6into olefins and oxygenated products(aldehydes, anhydrides,carboxylic acids) on metal oxide catalysts with cations of variable oxidation state, such as Mo and V in particular. Key parameters to be met by the catalysts, such as their redox properties, their structural aspects, active sites composed of ensembles of atoms isolated one from the others, mechanisms of reactions, are discussed. Main features of the different reactions of C_1–C_6alkanes and catalysts are analysed and their generalisation for determining more active and more selective catalysts is attempted. Prospective views for the future of the domain are proposed.
基金This study was supported by China National Natural Science Foundation Grants DI 48970108 and SHENG 39070073
文摘The authors studied the biomarkers (alkanes) of eight iron ore samples from Nianpanshan and Dsbaodui of Pangjiabao and Longguan, Xuanhua, Hebei. These samples have higher nC15-nC20 contents, with main peaks at nC16, nC 17 and nC18, and contain abundant pristane and phytane. These results indicate that iron stromatolite and iron oncolites in orebodies are sedimentary structures of algal origin. Sedimentary iron accumulation mainly results from activity of blue algae. This study provides new valuable evidence for the origin of Xuanlong-type iron deposits.
基金Supported by the National Nature Science Foundation of China.
文摘1 INTRODUCTIONAfter Prausnitz et al.published the perturbed hard-sphere chain theory(PHCT),manymodified theories have been put forward,such as the perturbed soft-sphere chain theory(PSCT),the perturbed anisotropic chain theory(PACT)and the associated perturbedanisotropic chain theory(APACT).These theories are all concerned with the parameter3c.But,Wertheim in his work proved that the free energy of hard-sphere chain couldbe calculated without 3c.Induced by the work done by Wertheim,Chapman
基金Supported by the Natural Science Fund of Hubei Educational Committee (99A088)
文摘A novel topological index derived from eccentric connectivity index bas been proposed. The new topological index and eccentric connectivity index were correlated with eight physical properties such as the boiling point, critical temperature, critical pressure, critical volume, evaporation heat, density, heat capaci- ty, surface tension, and three thermodynamic properties suck as standard enthalpy, standard entropy and standard formation free energy or alkanes. A series of empiric equations for calculating the properties were obtaines. Correlation coefficients or nine properties were more than 0. 99. Regression analysis and calcula- tion results indicated that the topological indices were well correlated with the physico-chemical properties or alkanes, and the novel topological index was far superior to eccentric connectivity index in the correlation.
基金National Key R&D Program of China (No.2018YFA0901101)the National Natural Science Foundation of China (Nos.22193050,92043301,22176203 and 22276212)the Sanming Project of Medicine in Shenzhen (No.SZSM201811070)。
文摘Investigating the development toxicity of perfuorinated iodine alkanes(PFIs)is critical,given their estrogenic effects through binding with estrogen receptors(ERs).In the present study,two PFIs,including dodecafuoro-1,6-diiodohexane(PFHx DI)and tridecafuorohexyl iodide(PFHx I),with binding preference to ERαand ERβ,respectively,were selected to evaluate their effects on proliferation and differentiation of the mouse embryonic stem cells(m ESCs).The results revealed that,similar to E_(2),50μmol/L PFHx DI accelerated the cell proliferation of the m ESCs.The PFI stimulation at the exposure concentrations of 2–50μmol/L promoted the differentiation of the m ESCs as characterized by the upregulation of differentiation-related biomarkers(i.e.,Otx2 and Dnmt3β)and downregulation of pluripotency genes(i.e.,Oct4,Nanog,Sox2,Prdm14 and Rex1).Comparatively,PFHx DI exhibited higher induction effect on the differentiation of the m ESCs than did PFHx I.The tests on ER signaling indicated that both PFI compounds induced exposure concentration-dependent expressions of ER signaling-related biomarkers(i.e.,ERα,ERβand Caveolin-1)in the m ESCs,and the downstream ER responsive genes(i.e.,c-fos,c-myc and c-jun)well responded to PFHx I stimulation.The role of ER in PFI-induced effects on the m ESCs was further validated by the antagonistic experiments using an ER inhibitor(ICI).The findings demonstrated that PFIs triggered ER signaling,and perturbed the differentiation program of the m ESCs,causing the potential health risk during early stage of development.
基金financial support from the University of South China。
文摘A simple,practical and eco-friendly visible light-induced alkylation of N-sulfonyl ketamine under metal-,additive-,external photocatalyst-free conditions was developed.This photocatalytic method utilized low cost and abundant alkanes as the atom economy alkyl sources with H2O2as the environmentally beneficial oxidant,allowing for the efficient construction of diverse valuable 4-alkylated sulfonyl ketamines.The N-sulfonyl ketamine played a dual role of reactant and photocatalyst,thus simplifying the reaction system.
文摘An electrostatic bond energy model is formulated to fit the enthalpies of formation and dipole moments of the alkanes and chloroalkanes. In this model, the charge distributions are calculated by an electrostatic approach similar to the "MSE" method, and the enthalpy of formation of a molecule is the sum of the bond energy terms plus the electrostatic energy of the interactions between the charges on all atoms. All parameters of this model are obtained by parameterization. The calculated dipole moments for 13 chloroalkanes and enthalpies of formation for 19 alkanes and non-geminal chloroalkanes agree with the determined values very well. To calculate the enthalpies of formation of geminal chloroalkanes, a correction mainly attributed to the van der Waals interactions in the geminal substituted group, about 24 kJ/mol per pair of geminal chlorine atoms, is introduced.
文摘A rather satisfactory method of synthesis of aldoximes and ketoximes by direct nitrosation of alkanes and an adequate technique of separating the mixtures and identifying the components from the reactions were worked out.By these procedures, the nitrosation of pentane, hexane and heptane gave different results from those reported in literature, and the study on octane was new.
文摘CO adsorption microcalorimetry was employed in the study of γ-Al-2O-3-supported Pt, Pt-Sn and Pt-Fe catalysts. The results indicated that the initial differential heat of CO adsorption of the Pt/γ-Al-2O-3 catalyst was 125 kJ/mol. As CO coverage increased, the differential heat of adsorption decreased. At higher coverages, the differential heat of adsorption decreased significantly. 60% of the differential heat of CO adsorption on the Pt/γ-Al-2O-3 catalyst was higher than 100 kJ/mol. No significant effect on the initial differential heat was found after adding Sn and Fe to the Pt/γ-Al-2O-3 catalyst. The amount of strong CO adsorption sites decreased, while the portion of CO adsorption sites with differential heat of 60110 kJ/mol increased after increasing the Sn or Fe content. This indicates that the surface adsorption energy was changed by adding Sn or Fe to Pt/γ-Al-2O-3. The distribution of differential heat of CO adsorption on the Pt-Sn（C）/γ-Al-2O-3 catalyst was broad and homogeneous. Comparison of the dehydrogenation performance of C-4 alkanes with the number of CO adsorption sites with differential heat of 60110 kJ/mol showed a good correlation. These results indicate that the surface Pt centers with differential heats of 60110 kJ/mol for CO adsorption possess superior activity for the dehydrogenation of alkanes.
基金Supported by National Natural Science Foundation of China (Grant Nos. 40472081 and 40772091)Yangtze University Foundation (Grant No. 05Z0504)
文摘Absolute concentration of normal alkanes(n-alkanes) and aromatic hydrocarbons in bitumen extracted from source rocks in the period of thermodegradation from Turpan-Hami Basin suggests that aromatic hydrocarbons are dominant in coal and carbargilite while n-alkanes are dominant in mudstones. Bulkrock analysis and gas chromatograph/mass spectrum(GC-MS) of source rocks shows aromatic hydrocarbons are dominant in total ion chromatograms(TIC) of samples with poor perhydrous macerals while n-alkanes are dominant in TICs of samples with abundant perhydrous macerals. The identification of oil-prone and gas prone property based on GC-MS of bitumen "A" together with bulkrock analysis indicates that source rocks from Shengbei area are more oil-prone while source rocks from Qiudong and Xiaocaohu areas are more gas-prone,coinciding with the distribution of oil and gas reservoirs in Taibei Sag. Ratios used to identify oil-prone and gas-prone property for source rocks from Turpan Basin are proposed:n-alkanes >110 μg·mg-1,aromatics <15 μg·mg-1,and n-alkanes/aromatics >8 for oil-prone source rock bitumen while n-alkanes<82 μg·mg-1,aromatics >40 μg·mg-1,and n-alkanes/aromatics <1.5 for gas-prone source rock bitumen.
基金This work was supported by the National Basic Research Program of China(No.2016YFA0202900)the National Natural Science Foundation of China(Nos.21825109,21821002,21572255,21732006)+1 种基金the Chinese Academy of Sciences Key Research Pro-gram of Frontier Sciences(No.QYZDB-SSw-SLHO16)the Sci-ence and Technology Commission of Shanghai Municipality(No.17JC1401200).
文摘A series of NCP-type pincer iridium complexes,(RNCCp)IrHCl(2a-2c)and(BQ-NCOP)IrHCl 3,have been studied for catalytic transfer alkane dehydrogenation.Complex 3 containing a rigid benzoquinoline backbone exhibits high activity and robustness in dehydrogenation of alkanes to form alkenes.Even more importantly,this catalyst system was also highly effective in the dehydrogenation of a wide range of heterocycles to furnish heteroarenes.
文摘Ⅰ. INTRODUCTION The oxidation of saturated hydrocarbons Was, in the past, concentrated in the oxidation of paraffin into mixed fatty acids, which were then used in industry in soapmaking, etc. Simple gaseous hydrocarbons, such as from methane and ethane were also used as subjects in the kinetical study of oxidation reactions. Reports of work focusing on the studies of synthesis of oxygen derivatives directly from oxidation of single alkane were few.
文摘Because of their inertmess toward chemical reagents, the chemistry of alkanes is rather poorly developed. The chlorination of alkanes was formerly done on mixtures such as paraffins and petroleum oils, the aim of which was to obtain solvents or their further hydrolytic products-alcohols, for technical uses. Reports on the study of the rules for the chlori-
