From the roots of Rhaponticum uniflorum a new triterpene was isolated together with ursolic acid(2), 3-oxo-19a-hydroxyurs-12-en-28-oic acid (3), pomolic acid (4), 2a,3a,19a-trihydroxyurs-12-en-28-oic acid (5), arctic ...From the roots of Rhaponticum uniflorum a new triterpene was isolated together with ursolic acid(2), 3-oxo-19a-hydroxyurs-12-en-28-oic acid (3), pomolic acid (4), 2a,3a,19a-trihydroxyurs-12-en-28-oic acid (5), arctic acid (6), catechin (7) and b-sitosterol (8). The structure of the new compound was elucidated as 2a,3a,19a,25-tetrahydroxyurs-12-en-23,28-dioic acid (1) on the basis of spectral and chemical methods.展开更多
[Objective]The study was to analyze the karyotype of Allium macrostemon Bunge in Laizhou City of Shandong Province.[ Method] The root tip of A. macrostemon was pretreated with 8-hydroxyquinoline solution, fixed, disso...[Objective]The study was to analyze the karyotype of Allium macrostemon Bunge in Laizhou City of Shandong Province.[ Method] The root tip of A. macrostemon was pretreated with 8-hydroxyquinoline solution, fixed, dissociated and stained for preparing the glass slide to reveal the chromosome number via the microscopic examination; the sparse cells with good chromosome morphology were photographed under microscope. [ Result ]Allium macrostemon Bunge in Laizhou City introduced in this study was tdploid; its somatic chromosome number was 24 and karyotype formula was K（2n） =3x=24m（2SAT） ＋ 1Bs, thus the karyotype belongs to 1A type. One of the chromosome No. 3 contained satellite, and chromosome deletion may be existed in one of the chromosome No. 5. In addition, B chromosome was observed in some cells.[ Conclusion] This introduction of triploid A. macrostemon found in China was the first time.展开更多
This ranearch is focused on the, develonment of a simnle design model of the submerged catalysis/membrane filtration （catalysis/MF） system for phenol hydroxylation over TS-1 based on the material balance of the phen...This ranearch is focused on the, develonment of a simnle design model of the submerged catalysis/membrane filtration （catalysis/MF） system for phenol hydroxylation over TS-1 based on the material balance of the phenol under steady state and the reported kinetic studies. Based on the developed model, the theoretical phenol Conversions at steady state could be calculated using the kinetic parameters obtained from the previous batch experiments. The theoretical conversions are in good agreement with the experimental data obtained in the submerged catalysis/MF system within relative error of ±5%. The model can be used to determine the optimal experimental conditions to carry out the phenol hydroxylation over TS-1 in the submerged catalysis/MF system.展开更多
A new type of reactor,featured with impinging stream-rotating packed bed（IS-RPB）and coil pipes,was designed and used to prepare p-hydroxybenzaldehyde（PHB）by hydrolysis from diazonium salts.The influence of operati...A new type of reactor,featured with impinging stream-rotating packed bed（IS-RPB）and coil pipes,was designed and used to prepare p-hydroxybenzaldehyde（PHB）by hydrolysis from diazonium salts.The influence of operating parameters,such as reaction temperature,reaction time and high gravity factor,on the yield of PHB was investigated.Compared with the traditional kettle-type reactor,the yield of PHB with the new reactor is increased significantly and the reaction time is much shorter.Under the optimum conditions,the yield of PHB is increased from 51%to 84.1%.The reactor offers an opportunity for replacing the traditional batch mode operation with a continuous process.展开更多
The reaction of HO2NO2 （peroxynitric acid, PNA） with OH was studied by the hybrid density functional B3LYP and CBS-QB3 methods. Based on the calculated potential energy surface, five reaction channels, H20＋NO2＋O2,...The reaction of HO2NO2 （peroxynitric acid, PNA） with OH was studied by the hybrid density functional B3LYP and CBS-QB3 methods. Based on the calculated potential energy surface, five reaction channels, H20＋NO2＋O2, HOOH＋NO3, NO2＋HO3H, HO2＋HONO2 and HO2＋HOONO, were examined in detail. The major reaction channel is PNA＋OH→M1→TS1→H2O＋NO2＋O2. Taking a pre-equilibrium approximation and using the CBS-QB3 energies, the theoretical rate constant of this channel was calculated as 1.13×10-12 cm^3/（molecule s） at 300 K, in agreement with the experimental result. Comparison between reactions of HOONO2＋OH and HONO2＋OH was carried out. For HOR＋OH reactions, the total rate constants increase from R=NO2 to R=ONO2, which is consistent with experimental measurements.展开更多
Levulinic acid is considered as a promising green platform chemical derived from biomass.The kinetics of levulinic acid accumulation in the hydrolysis process of wheat straw was investigated in the study.Using dilute ...Levulinic acid is considered as a promising green platform chemical derived from biomass.The kinetics of levulinic acid accumulation in the hydrolysis process of wheat straw was investigated in the study.Using dilute sulfuric acid as a catalyst,the kinetic experiments were performed in a temperature range of 190-230°C and an acid concentration range of 1%-5% (by mass) .A simple model of first-order series reactions was developed,which provided a satisfactory interpretation of the experimental results.The kinetics of main intermediates including sugar and 5-hydroxymethylfurfural(5-HMF) were also established.The kinetic parameters provided useful information for understanding the hydrolysis process.展开更多
Trans-sobrerol （Sob） and 8-p-menthen-1,2-diol （Limo-diol） are the primary products in the atmospheric oxidation of α-pinene and limonene, respectively. Because of their low volatility, they associate more likely ...Trans-sobrerol （Sob） and 8-p-menthen-1,2-diol （Limo-diol） are the primary products in the atmospheric oxidation of α-pinene and limonene, respectively. Because of their low volatility, they associate more likely to the liquid particles in the atmosphere, where they are subject to the aqueous phase oxidation by the atmospheric oxidants. In this work, through experimental and theoretical study, we first provide the rate constants of Sob and Limo-diol reacting with hydroxyl radical （.OH） in aqueous solution at room temperature of 3044-3 K and 1 atm pressure, which are （3.05±0.5）×10 9 and （4.57±0.2）×10 9 L/（mol.s）, respectively. Quantum chemistry calculations have also been employed to demonstrate the solvent effect on the rate constants in aqueous phase and the calculated results agree well with the measurements. Some reaction products have been identified based on liquid chromatography combined with mass spectroscopy and theoretical calculations.展开更多
A metabonomic approach was undertaken in order to detect urinary endogenous and exogenous metabolites and to evaluate the effects of passive exposure to cigarette sidestream smoke on rats. Urinary samples from three g...A metabonomic approach was undertaken in order to detect urinary endogenous and exogenous metabolites and to evaluate the effects of passive exposure to cigarette sidestream smoke on rats. Urinary samples from three groups of rats were determined including control rats, rats treated with blended cigarettes(nonmenthol cigarettes) and rats treated with menthol cigarettes. The total urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol(NNAL), total 1-hydroxypyrene(1-HOP) and 3-hydroxybenzo[a] pyrene(3-HOBaP) were determined for assessing exposure to cigarette sidestream smoke toxins. Urinary endogenous metabolites in the three groups of rats were also analyzed and the data were processed by chemometrics. Eleven endogenous metabolites were found and identified. Their relative levels were compared among the three groups. The results show that cigarette sidestream smoke has complex effect on rats. Blended cigarette group makes difference to menthol cigarette group in the rats' urinary metabolic changes. Menthol adding to cigarettes has positive and negative effects on rats, respectively. The urinary metabolic profiling of menthol cigarette group is closer to that of control group.展开更多
文摘From the roots of Rhaponticum uniflorum a new triterpene was isolated together with ursolic acid(2), 3-oxo-19a-hydroxyurs-12-en-28-oic acid (3), pomolic acid (4), 2a,3a,19a-trihydroxyurs-12-en-28-oic acid (5), arctic acid (6), catechin (7) and b-sitosterol (8). The structure of the new compound was elucidated as 2a,3a,19a,25-tetrahydroxyurs-12-en-23,28-dioic acid (1) on the basis of spectral and chemical methods.
基金Supported by the Program from Ludong University(043312)~~
文摘[Objective]The study was to analyze the karyotype of Allium macrostemon Bunge in Laizhou City of Shandong Province.[ Method] The root tip of A. macrostemon was pretreated with 8-hydroxyquinoline solution, fixed, dissociated and stained for preparing the glass slide to reveal the chromosome number via the microscopic examination; the sparse cells with good chromosome morphology were photographed under microscope. [ Result ]Allium macrostemon Bunge in Laizhou City introduced in this study was tdploid; its somatic chromosome number was 24 and karyotype formula was K（2n） =3x=24m（2SAT） ＋ 1Bs, thus the karyotype belongs to 1A type. One of the chromosome No. 3 contained satellite, and chromosome deletion may be existed in one of the chromosome No. 5. In addition, B chromosome was observed in some cells.[ Conclusion] This introduction of triploid A. macrostemon found in China was the first time.
基金Supported by the National-Basic Research Program of China （2009CB623406）, the National High Technology Research and Development Program of China （2007AA06A402） and the National Natural Science Foundation of China （20636020）.
文摘This ranearch is focused on the, develonment of a simnle design model of the submerged catalysis/membrane filtration （catalysis/MF） system for phenol hydroxylation over TS-1 based on the material balance of the phenol under steady state and the reported kinetic studies. Based on the developed model, the theoretical phenol Conversions at steady state could be calculated using the kinetic parameters obtained from the previous batch experiments. The theoretical conversions are in good agreement with the experimental data obtained in the submerged catalysis/MF system within relative error of ±5%. The model can be used to determine the optimal experimental conditions to carry out the phenol hydroxylation over TS-1 in the submerged catalysis/MF system.
基金Supported by the Science and Technology Key Projects of Shanxi Province(20090321113)
文摘A new type of reactor,featured with impinging stream-rotating packed bed（IS-RPB）and coil pipes,was designed and used to prepare p-hydroxybenzaldehyde（PHB）by hydrolysis from diazonium salts.The influence of operating parameters,such as reaction temperature,reaction time and high gravity factor,on the yield of PHB was investigated.Compared with the traditional kettle-type reactor,the yield of PHB with the new reactor is increased significantly and the reaction time is much shorter.Under the optimum conditions,the yield of PHB is increased from 51%to 84.1%.The reactor offers an opportunity for replacing the traditional batch mode operation with a continuous process.
基金ACKNOWLEDGMENT This work was supported by the National Natural Science Foundation of China （No.20473078）.
文摘The reaction of HO2NO2 （peroxynitric acid, PNA） with OH was studied by the hybrid density functional B3LYP and CBS-QB3 methods. Based on the calculated potential energy surface, five reaction channels, H20＋NO2＋O2, HOOH＋NO3, NO2＋HO3H, HO2＋HONO2 and HO2＋HOONO, were examined in detail. The major reaction channel is PNA＋OH→M1→TS1→H2O＋NO2＋O2. Taking a pre-equilibrium approximation and using the CBS-QB3 energies, the theoretical rate constant of this channel was calculated as 1.13×10-12 cm^3/（molecule s） at 300 K, in agreement with the experimental result. Comparison between reactions of HOONO2＋OH and HONO2＋OH was carried out. For HOR＋OH reactions, the total rate constants increase from R=NO2 to R=ONO2, which is consistent with experimental measurements.
基金Supported by the National Key Technology R&D Program of China (2007BAD66B04)
文摘Levulinic acid is considered as a promising green platform chemical derived from biomass.The kinetics of levulinic acid accumulation in the hydrolysis process of wheat straw was investigated in the study.Using dilute sulfuric acid as a catalyst,the kinetic experiments were performed in a temperature range of 190-230°C and an acid concentration range of 1%-5% (by mass) .A simple model of first-order series reactions was developed,which provided a satisfactory interpretation of the experimental results.The kinetics of main intermediates including sugar and 5-hydroxymethylfurfural(5-HMF) were also established.The kinetic parameters provided useful information for understanding the hydrolysis process.
基金This work was supported by the National Natural Science Foundation of China （No.21177041 and No.21107026）, the Fundamental Research Funds for the Central Universities （No.2013ZZ0073）, and the Scientific Research Foundation for Returned Overseas Chinese Scholars, State Education Ministry.
文摘Trans-sobrerol （Sob） and 8-p-menthen-1,2-diol （Limo-diol） are the primary products in the atmospheric oxidation of α-pinene and limonene, respectively. Because of their low volatility, they associate more likely to the liquid particles in the atmosphere, where they are subject to the aqueous phase oxidation by the atmospheric oxidants. In this work, through experimental and theoretical study, we first provide the rate constants of Sob and Limo-diol reacting with hydroxyl radical （.OH） in aqueous solution at room temperature of 3044-3 K and 1 atm pressure, which are （3.05±0.5）×10 9 and （4.57±0.2）×10 9 L/（mol.s）, respectively. Quantum chemistry calculations have also been employed to demonstrate the solvent effect on the rate constants in aqueous phase and the calculated results agree well with the measurements. Some reaction products have been identified based on liquid chromatography combined with mass spectroscopy and theoretical calculations.
基金Project(20805045)supported by National Natural Science Foundation of China
文摘A metabonomic approach was undertaken in order to detect urinary endogenous and exogenous metabolites and to evaluate the effects of passive exposure to cigarette sidestream smoke on rats. Urinary samples from three groups of rats were determined including control rats, rats treated with blended cigarettes(nonmenthol cigarettes) and rats treated with menthol cigarettes. The total urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol(NNAL), total 1-hydroxypyrene(1-HOP) and 3-hydroxybenzo[a] pyrene(3-HOBaP) were determined for assessing exposure to cigarette sidestream smoke toxins. Urinary endogenous metabolites in the three groups of rats were also analyzed and the data were processed by chemometrics. Eleven endogenous metabolites were found and identified. Their relative levels were compared among the three groups. The results show that cigarette sidestream smoke has complex effect on rats. Blended cigarette group makes difference to menthol cigarette group in the rats' urinary metabolic changes. Menthol adding to cigarettes has positive and negative effects on rats, respectively. The urinary metabolic profiling of menthol cigarette group is closer to that of control group.
