New descriptors were constructed and structures of some oxygen-containing organic compounds were parameterized. The multiple linear regression（MLR） and partial least squares regression（PLS） methods were employed t...New descriptors were constructed and structures of some oxygen-containing organic compounds were parameterized. The multiple linear regression（MLR） and partial least squares regression（PLS） methods were employed to build two relationship models between the structures and octanol/water partition coefficients（LogP） of the compounds. The modeling correlation coefficients（R） were 0.976 and 0.922, and the ＂leave one out＂ cross validation correlation coefficients（R（CV）） were 0.973 and 0.909, respectively. The results showed that the structural descriptors could well characterize the molecular structures of the compounds; the stability and predictive power of the models were good.展开更多
Based on theoretical linear solvation energy relationship and quantum chemical descriptors computed by AM1 Hamiltonian, a new model is developed to predict the partitioning of some volatile organic compounds between t...Based on theoretical linear solvation energy relationship and quantum chemical descriptors computed by AM1 Hamiltonian, a new model is developed to predict the partitioning of some volatile organic compounds between the plant cuticular matrix and air.展开更多
Polychlorinated biphenyls （PCBs） were measured in atmospheric samples collected from the North Pacific to the Arctic Ocean between July and September 2012 to study the atmospheric concentration characteris-tics of P...Polychlorinated biphenyls （PCBs） were measured in atmospheric samples collected from the North Pacific to the Arctic Ocean between July and September 2012 to study the atmospheric concentration characteris-tics of PCBs and their gas/particle partitioning. The mean concentration of 26 PCBs （vapor plus particulate phase） （∑PCBs） was 19.116 pg/m^3with a standard deviation of 13.833 pg/m^3. Three most abundant conge-ners were CB-28, -52 and -77, accounting for 43.0% to∑PCBs. The predominance of vapor PCBs （79.0% to∑PCBs） in the atmosphere was observed.∑PCBs were negative correlated with the latitudes and inverse of the absolute temperature （1/T）. The significant correlation for most congeners was also observed between the logarithm of gas/particle partition coefficient （logKp） and 1/T. Shallower slopes （from ∑0.15 to ∑0.46, average ∑0.27） were measured from the regression of the logarithm of sub-cooled liquid vapor pressures （logpoL） and logKP for all samples. The difference of the slopes and intercepts among samples was insignifi-cant （p〉0.1）, implying adsorption and/or absorption processes and the aerosol composition did not differ significantly among different samples. By comparing three models, the J-P adsorption model, the octanol/air partition coefficient （KOA） based model and the soot-air model, the gas/particle partitioning of PCBs in the Arctic atmosphere was simulated more precisely by the soot-air model, and the adsorption onto el-emental carbon is more sensitive than the absorption into organic matters of aerosols, especially for low-chlorinated PCB congeners.展开更多
Based on the theoretical linear solvation energy relationship and quantum chemical descriptors computed by AM1 Hamiltonian, a new approach was developed to predict the partitioning of some organic compounds between th...Based on the theoretical linear solvation energy relationship and quantum chemical descriptors computed by AM1 Hamiltonian, a new approach was developed to predict the partitioning of some organic compounds between the airborne particulate and air. It could be successfully used to study the partitioning of organic compounds from air into airborne particulate, and evaluate the potential risk of or-ganic compounds.展开更多
A mass transfer model for devolatilization process of highly viscous media in rotating packed bed(RPB) was developed based on penetration theory and mass conservation.Before establishing the model,some mass transfer e...A mass transfer model for devolatilization process of highly viscous media in rotating packed bed(RPB) was developed based on penetration theory and mass conservation.Before establishing the model,some mass transfer experiments of thin film were conducted in a designed diffusion cell including vacuum and feeding system. In this study,acetone was used as the volatile organic compound(VOC) and syrup as the highly viscous media.The thickness of thin film was changed by using different liquid distributor.It was found that bubbling played an important role in the devolatilization.The correlation of diffusion coefficient of acetone in highly viscous dilute solution was proposed.The relative error between predicted and experimental data was within the range of ± 30% for diffusion coefficient of acetone in syrup.A comparison of experimental data of RPB with model indicated that the relative error was within ± 30% for efficiency of acetone removal.展开更多
Rate coefficients for the reaction of N03 radicals with 6 unsaturated volatile organic compounds(VOCs) in a 7300 L simulation chamber at ambient temperature and pressure have been determined by the relative rate metho...Rate coefficients for the reaction of N03 radicals with 6 unsaturated volatile organic compounds(VOCs) in a 7300 L simulation chamber at ambient temperature and pressure have been determined by the relative rate method.The resulting rate coefficients were determined for isoprene,2-carene,3-carene,methyl vinyl ketone(MVK),methacrolein(MACR)and crotonaldehyde(CA),as(6.6±0.8)×10-13,(1.8±0.6)×10-11,(8.7±0.5)×10-12,(1.24±1.04)×10-16,(3.3±0.9)×10-15 and(5.7±1.2)×10-15 cm3/(molecule·sec),respectively.The experiments indicate that NO3 radical reactions with all the studied unsaturated VOGs proceed through addition to the olefinic bond,however,it indicates that the introduction of a carbonyl group into unsaturated VOGs can deactivate the neighboring olefinic bond towards reaction with the NO3 radical,which is to be expected since the presence of these electronwithdrawing substituents will reduce the electron density in the π orbitals of the alkenes,and will therefore reduce the rate coefficient of these electrophilic addition reactions.In addition,we investigated the product formation from the reactions of 2-carene and 3-carene with the NO3 radical.Qualitative identification of an epoxide(C10H16OH+),caronaldehyde(C10H16O2 H+) and nitrooxy-ketone(C10H16O4 NH+) was achieved using a proton transfer reaction time-of-flight mass spectrometer(PTR-TOF-MS) and a reaction mechanism is proposed.展开更多
logP is an importat paramter for evaluating the hydrophobicity of organic compounds and other species. It is widely used in 2D-QSAR and recently in 3D-QSAR studies. On the basis of the current fragment addition method...logP is an importat paramter for evaluating the hydrophobicity of organic compounds and other species. It is widely used in 2D-QSAR and recently in 3D-QSAR studies. On the basis of the current fragment addition method, we proposed a new algo rithm called XLOGP by introducing atomic paramters like atom accessible surfaces, van der Waals volums and partial charges. Step-wise multiple regression on a test set of 400 orgtanic compounds were carried out. The model was then tested by cross-validation. The final correlation coefficient for the whole data set fitting and for cross -validation is 0.982 and 0.971, respectively. This shows that the model obtained is valid both at data fitting and at prediction. Compared to other algorithm, this method can discriminate a common atom or fragment in different environment.展开更多
基金supported by the Youth Foundation of Education Bureau,Sichuan Province(13ZB0003)
文摘New descriptors were constructed and structures of some oxygen-containing organic compounds were parameterized. The multiple linear regression（MLR） and partial least squares regression（PLS） methods were employed to build two relationship models between the structures and octanol/water partition coefficients（LogP） of the compounds. The modeling correlation coefficients（R） were 0.976 and 0.922, and the ＂leave one out＂ cross validation correlation coefficients（R（CV）） were 0.973 and 0.909, respectively. The results showed that the structural descriptors could well characterize the molecular structures of the compounds; the stability and predictive power of the models were good.
文摘Based on theoretical linear solvation energy relationship and quantum chemical descriptors computed by AM1 Hamiltonian, a new model is developed to predict the partitioning of some volatile organic compounds between the plant cuticular matrix and air.
基金The Chinese Polar Environment Comprehensive Investigation and Assessment Programs under contract Nos 02-01,03-04,04-01 and 04-03the National Natural Science Fundation of China under contract No.21377032
文摘Polychlorinated biphenyls （PCBs） were measured in atmospheric samples collected from the North Pacific to the Arctic Ocean between July and September 2012 to study the atmospheric concentration characteris-tics of PCBs and their gas/particle partitioning. The mean concentration of 26 PCBs （vapor plus particulate phase） （∑PCBs） was 19.116 pg/m^3with a standard deviation of 13.833 pg/m^3. Three most abundant conge-ners were CB-28, -52 and -77, accounting for 43.0% to∑PCBs. The predominance of vapor PCBs （79.0% to∑PCBs） in the atmosphere was observed.∑PCBs were negative correlated with the latitudes and inverse of the absolute temperature （1/T）. The significant correlation for most congeners was also observed between the logarithm of gas/particle partition coefficient （logKp） and 1/T. Shallower slopes （from ∑0.15 to ∑0.46, average ∑0.27） were measured from the regression of the logarithm of sub-cooled liquid vapor pressures （logpoL） and logKP for all samples. The difference of the slopes and intercepts among samples was insignifi-cant （p〉0.1）, implying adsorption and/or absorption processes and the aerosol composition did not differ significantly among different samples. By comparing three models, the J-P adsorption model, the octanol/air partition coefficient （KOA） based model and the soot-air model, the gas/particle partitioning of PCBs in the Arctic atmosphere was simulated more precisely by the soot-air model, and the adsorption onto el-emental carbon is more sensitive than the absorption into organic matters of aerosols, especially for low-chlorinated PCB congeners.
基金This work was supported by the National Key Basic Research Program(Grant No.G 1999045708-03-01).
文摘Based on the theoretical linear solvation energy relationship and quantum chemical descriptors computed by AM1 Hamiltonian, a new approach was developed to predict the partitioning of some organic compounds between the airborne particulate and air. It could be successfully used to study the partitioning of organic compounds from air into airborne particulate, and evaluate the potential risk of or-ganic compounds.
基金Supported by the National Natural Science Foundation of China（20821004 20990221） the National High Technology Research and Development Program of China（2006AA030202）+1 种基金 the Program for New Century Excellent Talents in University of China（NCET-07-0053） the National Basic Research Program of China（2009CB219903）
文摘A mass transfer model for devolatilization process of highly viscous media in rotating packed bed(RPB) was developed based on penetration theory and mass conservation.Before establishing the model,some mass transfer experiments of thin film were conducted in a designed diffusion cell including vacuum and feeding system. In this study,acetone was used as the volatile organic compound(VOC) and syrup as the highly viscous media.The thickness of thin film was changed by using different liquid distributor.It was found that bubbling played an important role in the devolatilization.The correlation of diffusion coefficient of acetone in highly viscous dilute solution was proposed.The relative error between predicted and experimental data was within the range of ± 30% for diffusion coefficient of acetone in syrup.A comparison of experimental data of RPB with model indicated that the relative error was within ± 30% for efficiency of acetone removal.
基金supported by Labex Voltaire(No.ANR-10-LABX100-01)the French National Research Agency(Agence Nationale de la Recherche)and the Research Grants Council(ANR-RGC)program(project ANR-16-CE01-0013)+2 种基金ARD PIVOTS program(Ambition Recherche Développement Plateformes d’Innovation,de Valorisation,d’Optimisation,Technologiques environnmentale S,supported by the centre-Val de Loire regional council)funding from the European Union’s Horizon 2020 research and innovation program through the EUROCHAMP-2020 Infrastructure Activity(No.730997)the Marie Sk?odowska Curie Actions Programme(No.690958)(MARSU)
文摘Rate coefficients for the reaction of N03 radicals with 6 unsaturated volatile organic compounds(VOCs) in a 7300 L simulation chamber at ambient temperature and pressure have been determined by the relative rate method.The resulting rate coefficients were determined for isoprene,2-carene,3-carene,methyl vinyl ketone(MVK),methacrolein(MACR)and crotonaldehyde(CA),as(6.6±0.8)×10-13,(1.8±0.6)×10-11,(8.7±0.5)×10-12,(1.24±1.04)×10-16,(3.3±0.9)×10-15 and(5.7±1.2)×10-15 cm3/(molecule·sec),respectively.The experiments indicate that NO3 radical reactions with all the studied unsaturated VOGs proceed through addition to the olefinic bond,however,it indicates that the introduction of a carbonyl group into unsaturated VOGs can deactivate the neighboring olefinic bond towards reaction with the NO3 radical,which is to be expected since the presence of these electronwithdrawing substituents will reduce the electron density in the π orbitals of the alkenes,and will therefore reduce the rate coefficient of these electrophilic addition reactions.In addition,we investigated the product formation from the reactions of 2-carene and 3-carene with the NO3 radical.Qualitative identification of an epoxide(C10H16OH+),caronaldehyde(C10H16O2 H+) and nitrooxy-ketone(C10H16O4 NH+) was achieved using a proton transfer reaction time-of-flight mass spectrometer(PTR-TOF-MS) and a reaction mechanism is proposed.
文摘logP is an importat paramter for evaluating the hydrophobicity of organic compounds and other species. It is widely used in 2D-QSAR and recently in 3D-QSAR studies. On the basis of the current fragment addition method, we proposed a new algo rithm called XLOGP by introducing atomic paramters like atom accessible surfaces, van der Waals volums and partial charges. Step-wise multiple regression on a test set of 400 orgtanic compounds were carried out. The model was then tested by cross-validation. The final correlation coefficient for the whole data set fitting and for cross -validation is 0.982 and 0.971, respectively. This shows that the model obtained is valid both at data fitting and at prediction. Compared to other algorithm, this method can discriminate a common atom or fragment in different environment.
