Nitrous acid, HNO2, is an important precursor of OH radicals in the troposphere. Measurements of HNO2 and NO2, using differential optical absorption spectroscopy （DOAS）, were performed in Shanghai, China for a perio...Nitrous acid, HNO2, is an important precursor of OH radicals in the troposphere. Measurements of HNO2 and NO2, using differential optical absorption spectroscopy （DOAS）, were performed in Shanghai, China for a period from October 22, 2004 to January 4, 2005. The mean （and median） hourly concentrations of HNO2 and NO2 during this period were 1.1 （0.7） ppb and 24 （21.4） ppb respectively. A correlation between HNO2/NO2 and PM10 mass concentrations was obtained. This correlation suggests that significant heterogeneous chemical production of HNO2 may occur through NO2 reactions on aerosol surfaces. This hypothesis was further supported by detailed analysis of selected pollution episodes in this study. At the same time, the water dependence of HNO2 formation was studied by analysis of relative humidity （RH）. It showed that the maximum HNO2/NO2 ratio was increased along with RH below 70% and inhibited at RH〉70%.展开更多
Alpha radiolysis of nitric acid aqueous solution by a ^(238)Pu source is investigated experimentally and theoretically.The time dependence of the nitrous acid yield on dose rate,nitric acid concentration,and nitrate i...Alpha radiolysis of nitric acid aqueous solution by a ^(238)Pu source is investigated experimentally and theoretically.The time dependence of the nitrous acid yield on dose rate,nitric acid concentration,and nitrate ion concentration is studied.A novel kinetic model for the α-radiolysis of nitric acid aqueous solution is established,by considering the direct and indirect effects.The simulation results agree well with the experimental data,indicating the validity of our model to treat the reaction paths for generation and consumption of nitrous acid.It is shown that the redox reactions involving Pu cannot be neglected in theα-radiolysis of the solution.The results provide a better understanding of the α-ray radiolysis of aqueous nitric acid.展开更多
基金The National Natural Science Foundation of China (No. 20277006) and the Fudan University Foundation for Young Scientists (No.EXH 6286301)
文摘Nitrous acid, HNO2, is an important precursor of OH radicals in the troposphere. Measurements of HNO2 and NO2, using differential optical absorption spectroscopy （DOAS）, were performed in Shanghai, China for a period from October 22, 2004 to January 4, 2005. The mean （and median） hourly concentrations of HNO2 and NO2 during this period were 1.1 （0.7） ppb and 24 （21.4） ppb respectively. A correlation between HNO2/NO2 and PM10 mass concentrations was obtained. This correlation suggests that significant heterogeneous chemical production of HNO2 may occur through NO2 reactions on aerosol surfaces. This hypothesis was further supported by detailed analysis of selected pollution episodes in this study. At the same time, the water dependence of HNO2 formation was studied by analysis of relative humidity （RH）. It showed that the maximum HNO2/NO2 ratio was increased along with RH below 70% and inhibited at RH〉70%.
基金partly supported by the National Natural Science Foundation of China(No.21377122)
文摘Alpha radiolysis of nitric acid aqueous solution by a ^(238)Pu source is investigated experimentally and theoretically.The time dependence of the nitrous acid yield on dose rate,nitric acid concentration,and nitrate ion concentration is studied.A novel kinetic model for the α-radiolysis of nitric acid aqueous solution is established,by considering the direct and indirect effects.The simulation results agree well with the experimental data,indicating the validity of our model to treat the reaction paths for generation and consumption of nitrous acid.It is shown that the redox reactions involving Pu cannot be neglected in theα-radiolysis of the solution.The results provide a better understanding of the α-ray radiolysis of aqueous nitric acid.
