A method of GC determination using tetracosane as the internal standard for active cannabinoids cannabidiol.△~9-tetrahydrocannabinol and cannabinol of cannabis is described.The method is simple and accurate and has b...A method of GC determination using tetracosane as the internal standard for active cannabinoids cannabidiol.△~9-tetrahydrocannabinol and cannabinol of cannabis is described.The method is simple and accurate and has been applied to investigate the contents of active cannabinoids in cannabis of Chinese origin.Information was obtained from provinces and autonomous region of China. Three pure cannabinoids used as the reference substances were extracted and isolated successfully from cannabis.展开更多
The interaction by hydrogen bond formation of some primary alcohols （ l-heptanol, l-octanol and l-decanol） with esters （methyl methacrylate, ethyl methacrylate and butyl methacrylate） was investigated in non-polar...The interaction by hydrogen bond formation of some primary alcohols （ l-heptanol, l-octanol and l-decanol） with esters （methyl methacrylate, ethyl methacrylate and butyl methacrylate） was investigated in non-polar solvents viz., n-heptane, CC14 and benzene by means of FTIR spectroscopy. Formation constants and free energy changes of complex formation were determined. The dependence of the equilibrium constants and free energy changes of complex formation on the alkyl chain length of both the alcohols and esters are discussed. The solvent interaction between the solute and solvent. effect on the hydrogen bond formation is discussed in terms of specific展开更多
An efficient analytical method combining pyrolysis and capillary GC/MS has been developed for determination and quantitation of targeted polycyclic aromatic hydrocarbons.The limit of detection ranged from 0.29 μg/g t...An efficient analytical method combining pyrolysis and capillary GC/MS has been developed for determination and quantitation of targeted polycyclic aromatic hydrocarbons.The limit of detection ranged from 0.29 μg/g to 43.46 μg/g,and repeatability values were between 0.1% and 8.2% for blank spiked samples and between 0.1 % and 9.8% for real samples of heavy oils.Through application of the proposed method in hydrotreating processes,it has been found out that heavy oils before and after the specified hydroprocessing treatment exhibited a diverse PAHs distribution which might be determined by the discrepancy in their intrinsic contents and hydrogenation reactivity.Furthermore,the hydrogenation reactivity of different polycyclic aromatic hydrocarbons was further investigated and discovered to be more interrelated to molecular structure and rings alignment or conjugation mode.展开更多
The laser-induced fluorescence （LIF） excitation spectrum of NiH was recorded in the spectral region from 15000 cm^-1 to 21400 cm^-1, with the NiH molecules produced by the reaction of sputtered nickel atoms with met...The laser-induced fluorescence （LIF） excitation spectrum of NiH was recorded in the spectral region from 15000 cm^-1 to 21400 cm^-1, with the NiH molecules produced by the reaction of sputtered nickel atoms with methanol under supersonic jet conditions. The 19000-21400 cm^-1 portion of the spectrum of NiH is reported for the first time. Twenty-four bands were observed and classified into seven electronic transitions. Every band was rotationally analyzed. Higher vibrational levels of many excited states, A, B, D, E, F, and G, were observed and the complete set of spectroscopic parameters, vibrational frequency, unharmonic constant, rotational constant, and equilibrium length of these states were obtained. Some bands were reassigned.展开更多
Coal seam pyrolysis occurs during coal seam fires and during underground coal gasification. This is an important source of polycyclic aromatic hydrocarbon （PAH） emission in China. Pyrolysis in a coal seam was simula...Coal seam pyrolysis occurs during coal seam fires and during underground coal gasification. This is an important source of polycyclic aromatic hydrocarbon （PAH） emission in China. Pyrolysis in a coal seam was simulated in a tubular furnace. The 16 US Environmental Protection Agency priority controlled PAHs were analyzed by HPLC. The effects of temperature, heating rate, pyrolysis atmosphere, and coal size were investigated. The results indicate that the 3-ring PAHs AcP and AcPy are the main species in the pyrolysis gas. The 2-ring NaP and the 4-ring Pyr are also of concern. Increasing temperature caused the total PAH yield to go through a minimum. The lowest value was obtained at the temperature of 600℃. Higher heating rates promote PAH formation, especially formation of the lower molecular weight PAHs. The typical heating rate in a coal seam, 5 ℃/min, results in intermediate yields of PAHs. The total PAHs yield in an atmosphere of N2 is about 1.81 times that seen without added N2, which indicates that an air flow through the coal seam accelerates the formation of PAHs. An increase in coal particle size reduces the total PAHs emission but promotes the formation of 5- and f-ring PAHs.展开更多
Hydroxy-phenyl)-5-(2-methyl-phenyl)-6-ethoxycarbonyl-cyclohexen-2-one has been synthesized and characterized by elemental analysis, IR, UV, H NMR and MS, and its crystal 1 structure was determined by X-ray single-crys...Hydroxy-phenyl)-5-(2-methyl-phenyl)-6-ethoxycarbonyl-cyclohexen-2-one has been synthesized and characterized by elemental analysis, IR, UV, H NMR and MS, and its crystal 1 structure was determined by X-ray single-crystal diffraction method. The crystal belongs to the monoclinic system, space group P21/c with a = 14.6298(13), b = 5.8623(5), c = 22.255(2) ?, β = 105.855(2)o, V = 1836.0(3) ?3, Mr = 350.40, Z = 4, Dc = 1.268 g/cm3, F(000) = 744, μ(MoKα) = 0.086 mm-1, R = 0.0680 and wR = 0.1498. The crystal analysis results show that the cyclohexene unit of the title compound has a quasi-chair conformation, and a centrosymmetric dimer with a 16-membered ring is produced by the intermolecular hydrogen bonds.展开更多
Two new noble-metal-free molecular devices, [{Co（dmgH）2Cl}{Zn（PyTPP）}] （1, dmgH = dimethyloxime, PyTPP = 5-（4- pyridyl）-10,15,20-triphenylporphyrin） and [{Co（dmgH）2Cl}{Zn（apPyTPP）}] （2, apPyTPP = 5-[4-（i...Two new noble-metal-free molecular devices, [{Co（dmgH）2Cl}{Zn（PyTPP）}] （1, dmgH = dimethyloxime, PyTPP = 5-（4- pyridyl）-10,15,20-triphenylporphyrin） and [{Co（dmgH）2Cl}{Zn（apPyTPP）}] （2, apPyTPP = 5-[4-（isonicotinamidyl）phenyl]- 10,15,20-triphenylporphyrin）, for light-driven hydrogen generation were prepared and spectroscopically characterized. The zinc porphyrin photosensitizer and the Co III-based catalyst unit are linked by axial coordination of a pyridyl group in the periphery of zinc-porphyrin to the cobalt centre of catalyst with different lengths of bridges. The apparent fluorescence quenching and lifetime decays of 1 and 2 were observed in comparison with their reference chromophores, Zn（PyTPP） （3） and Zn（apPyTPP） （4）, suggesting a possibility for an intramolecular electron transfer from the singlet excited state of zinc porphyrin unit to the cobalt centre in the molecular devices. Photochemical H2-evolving studies show that complexes 1 and 2 are efficient molecular photocatalysts for visible light-driven H2 generation from water with triethylamine as a sacrificial electron donor in THF/H20, with turnover numbers up to 46 and 35 for 1 and 2, respectively. In contrast to these molecular devices, the multicomponent catalyst of zinc porphyrin and [Co（dmgH）2PyCl] did not show any fluorescence quenching and as a consequence, no H2 gas was detected by GC analysis in the presence of triethylamine with irradiation of visible light. The plausible mechanism for the photochemical H2 generation with these molecular devices is discussed.展开更多
文摘A method of GC determination using tetracosane as the internal standard for active cannabinoids cannabidiol.△~9-tetrahydrocannabinol and cannabinol of cannabis is described.The method is simple and accurate and has been applied to investigate the contents of active cannabinoids in cannabis of Chinese origin.Information was obtained from provinces and autonomous region of China. Three pure cannabinoids used as the reference substances were extracted and isolated successfully from cannabis.
文摘The interaction by hydrogen bond formation of some primary alcohols （ l-heptanol, l-octanol and l-decanol） with esters （methyl methacrylate, ethyl methacrylate and butyl methacrylate） was investigated in non-polar solvents viz., n-heptane, CC14 and benzene by means of FTIR spectroscopy. Formation constants and free energy changes of complex formation were determined. The dependence of the equilibrium constants and free energy changes of complex formation on the alkyl chain length of both the alcohols and esters are discussed. The solvent interaction between the solute and solvent. effect on the hydrogen bond formation is discussed in terms of specific
基金support from the National Key Basic Research Science Foundation (Grant No. 2006CB202500. 4-1)
文摘An efficient analytical method combining pyrolysis and capillary GC/MS has been developed for determination and quantitation of targeted polycyclic aromatic hydrocarbons.The limit of detection ranged from 0.29 μg/g to 43.46 μg/g,and repeatability values were between 0.1% and 8.2% for blank spiked samples and between 0.1 % and 9.8% for real samples of heavy oils.Through application of the proposed method in hydrotreating processes,it has been found out that heavy oils before and after the specified hydroprocessing treatment exhibited a diverse PAHs distribution which might be determined by the discrepancy in their intrinsic contents and hydrogenation reactivity.Furthermore,the hydrogenation reactivity of different polycyclic aromatic hydrocarbons was further investigated and discovered to be more interrelated to molecular structure and rings alignment or conjugation mode.
文摘The laser-induced fluorescence （LIF） excitation spectrum of NiH was recorded in the spectral region from 15000 cm^-1 to 21400 cm^-1, with the NiH molecules produced by the reaction of sputtered nickel atoms with methanol under supersonic jet conditions. The 19000-21400 cm^-1 portion of the spectrum of NiH is reported for the first time. Twenty-four bands were observed and classified into seven electronic transitions. Every band was rotationally analyzed. Higher vibrational levels of many excited states, A, B, D, E, F, and G, were observed and the complete set of spectroscopic parameters, vibrational frequency, unharmonic constant, rotational constant, and equilibrium length of these states were obtained. Some bands were reassigned.
基金provided by the National Natural Science Foundation of China (No. 50876112)the Fundamental Research Funds for the Central Universities (No. 2009QH13)the International Scientific and Technological Cooperation Project(No. 2010DFR60610)
文摘Coal seam pyrolysis occurs during coal seam fires and during underground coal gasification. This is an important source of polycyclic aromatic hydrocarbon （PAH） emission in China. Pyrolysis in a coal seam was simulated in a tubular furnace. The 16 US Environmental Protection Agency priority controlled PAHs were analyzed by HPLC. The effects of temperature, heating rate, pyrolysis atmosphere, and coal size were investigated. The results indicate that the 3-ring PAHs AcP and AcPy are the main species in the pyrolysis gas. The 2-ring NaP and the 4-ring Pyr are also of concern. Increasing temperature caused the total PAH yield to go through a minimum. The lowest value was obtained at the temperature of 600℃. Higher heating rates promote PAH formation, especially formation of the lower molecular weight PAHs. The typical heating rate in a coal seam, 5 ℃/min, results in intermediate yields of PAHs. The total PAHs yield in an atmosphere of N2 is about 1.81 times that seen without added N2, which indicates that an air flow through the coal seam accelerates the formation of PAHs. An increase in coal particle size reduces the total PAHs emission but promotes the formation of 5- and f-ring PAHs.
基金This work was financially supported by the Education Committee of Hunan Province (02C465)Hunan Provincial Key Discipline and Hunan Provincial General College Leader of Learning
文摘Hydroxy-phenyl)-5-(2-methyl-phenyl)-6-ethoxycarbonyl-cyclohexen-2-one has been synthesized and characterized by elemental analysis, IR, UV, H NMR and MS, and its crystal 1 structure was determined by X-ray single-crystal diffraction method. The crystal belongs to the monoclinic system, space group P21/c with a = 14.6298(13), b = 5.8623(5), c = 22.255(2) ?, β = 105.855(2)o, V = 1836.0(3) ?3, Mr = 350.40, Z = 4, Dc = 1.268 g/cm3, F(000) = 744, μ(MoKα) = 0.086 mm-1, R = 0.0680 and wR = 0.1498. The crystal analysis results show that the cyclohexene unit of the title compound has a quasi-chair conformation, and a centrosymmetric dimer with a 16-membered ring is produced by the intermolecular hydrogen bonds.
基金supported by the National Natural Science Foundation of China (20633020)the National Basic Research Program of China(2009CB220009)+2 种基金the Swedish Energy Agencythe Swedish Research Councilthe K & A Wallenberg Foundation
文摘Two new noble-metal-free molecular devices, [{Co（dmgH）2Cl}{Zn（PyTPP）}] （1, dmgH = dimethyloxime, PyTPP = 5-（4- pyridyl）-10,15,20-triphenylporphyrin） and [{Co（dmgH）2Cl}{Zn（apPyTPP）}] （2, apPyTPP = 5-[4-（isonicotinamidyl）phenyl]- 10,15,20-triphenylporphyrin）, for light-driven hydrogen generation were prepared and spectroscopically characterized. The zinc porphyrin photosensitizer and the Co III-based catalyst unit are linked by axial coordination of a pyridyl group in the periphery of zinc-porphyrin to the cobalt centre of catalyst with different lengths of bridges. The apparent fluorescence quenching and lifetime decays of 1 and 2 were observed in comparison with their reference chromophores, Zn（PyTPP） （3） and Zn（apPyTPP） （4）, suggesting a possibility for an intramolecular electron transfer from the singlet excited state of zinc porphyrin unit to the cobalt centre in the molecular devices. Photochemical H2-evolving studies show that complexes 1 and 2 are efficient molecular photocatalysts for visible light-driven H2 generation from water with triethylamine as a sacrificial electron donor in THF/H20, with turnover numbers up to 46 and 35 for 1 and 2, respectively. In contrast to these molecular devices, the multicomponent catalyst of zinc porphyrin and [Co（dmgH）2PyCl] did not show any fluorescence quenching and as a consequence, no H2 gas was detected by GC analysis in the presence of triethylamine with irradiation of visible light. The plausible mechanism for the photochemical H2 generation with these molecular devices is discussed.
