The atmospheric concentrations of carbonyls and BTEX （benzene,toluene,ethylbenzene,m,p-xylene and o-xylene） were measured simultaneously at a same sampling site in Beijing from September 2008 to August 2010.The aver...The atmospheric concentrations of carbonyls and BTEX （benzene,toluene,ethylbenzene,m,p-xylene and o-xylene） were measured simultaneously at a same sampling site in Beijing from September 2008 to August 2010.The average concentrations of the total measured carbonyls during autumn,winter,spring,and summer were 37.7,31.3,39.7,50.5 μg/m 3,respectively,and maximal values for their diurnal variations usually happened at noontime.In contrast to carbonyls,the average concentrations of the total measured BTEX during the four seasons were 27.2,31.9,23.2,19.1 μg/m 3,respectively,andminimal values for their diurnal variations always occurred in the early afternoon.The average concentration for carbonyls increased about 24% from September 2008–August 2009 to September 2009–August 2010,for BTEX,increased about 15%.Integrated life time cancer risks for three carcinogens （benzene,formaldehyde and acetaldehyde） in Beijing exceeded the value of 1E-06,and the hazard quotient （HQ） of non-cancer risk of exposure to formaldehyde exceeded unity.展开更多
A highly efficient Pd\|BMImCl/TiO\-\%y\%\|SiO\-\%x\% catalyst system synthesized through sol\|gel method from palladium complex, ionic liquid, titanate and silicate esters was found for the oxidative carbonylation of ...A highly efficient Pd\|BMImCl/TiO\-\%y\%\|SiO\-\%x\% catalyst system synthesized through sol\|gel method from palladium complex, ionic liquid, titanate and silicate esters was found for the oxidative carbonylation of amines. The catalyst efficiency was much higher than that reported in previous papers and the TOF number reached to 10 372 when catalyst 0.05%Pd\|4.6%BMImCl/TiO\-\%y\%\|SiO\-\%x\% was used. The usability of ionic liquid was the key point for preparation of this catalyst system because of its high dissolvability to palladium complex and affording appropriate micro\|environment for the reaction. The synergism among palladium complex, ionic liquid, titanate and silicate was the main reason for the high catalytic activity of the catalyst system. BET, AES and XRD were used to characterized the catalysts in detail.展开更多
Fifteen heavy-duty diesel vehicles were tested on chassis dynamometer by using typical heavy duty driving cycle and fuel economy cycle. The air from the exhaust was sampled by 2,4- dinitrophenyhydrazine cartridge and ...Fifteen heavy-duty diesel vehicles were tested on chassis dynamometer by using typical heavy duty driving cycle and fuel economy cycle. The air from the exhaust was sampled by 2,4- dinitrophenyhydrazine cartridge and 23 carbonyl compounds were analyzed by high performance liquid chromatography. The average emission factor of carbonyls was 97.2 mg/km, higher than that of light-duty diesel vehicles and gasoline-powered vehicles. Formaldehyde, acetaldehyde, acetone and propionaidehyde were the species with the highest emission factors. Main influencing factors for carbonyl emissions were vehicle type, average speed and regulated emission standard, and the impact of vehicle loading was not evident in this study. National emission of carbonyls from diesel vehicles exhaust was calculated for China, 2011, based on both vehicle miles traveled and fuel consumption. Carbonyl emission of diesel vehicle was estimated to be 45.8 Gg, and was comparable to gasolinepowered vehicles （58.4 Gg）. The emissions of formaldehyde, acetaldehyde and acetone were 12.6, 6.9, 3.8 Gg, respectively. The ozone formation potential of carbonyls from diesel vehicles exhaust was 537 mg O3/km, higher than 497 mg O3/km of none-methane hydrocarbons emitted from diesel vehicles.展开更多
基金supported by the National Natural Science Foundation of China (No. 41075094,40830101, 21177140,20977097)the National Basic Research and the Development Program (973) of China (No. 2010CB732304)+1 种基金the Special Fund for Environmental Research in the Public Interest (No. 201009001)the National Water Special Project (No. 2009ZX07210-009)
文摘The atmospheric concentrations of carbonyls and BTEX （benzene,toluene,ethylbenzene,m,p-xylene and o-xylene） were measured simultaneously at a same sampling site in Beijing from September 2008 to August 2010.The average concentrations of the total measured carbonyls during autumn,winter,spring,and summer were 37.7,31.3,39.7,50.5 μg/m 3,respectively,and maximal values for their diurnal variations usually happened at noontime.In contrast to carbonyls,the average concentrations of the total measured BTEX during the four seasons were 27.2,31.9,23.2,19.1 μg/m 3,respectively,andminimal values for their diurnal variations always occurred in the early afternoon.The average concentration for carbonyls increased about 24% from September 2008–August 2009 to September 2009–August 2010,for BTEX,increased about 15%.Integrated life time cancer risks for three carcinogens （benzene,formaldehyde and acetaldehyde） in Beijing exceeded the value of 1E-06,and the hazard quotient （HQ） of non-cancer risk of exposure to formaldehyde exceeded unity.
文摘A highly efficient Pd\|BMImCl/TiO\-\%y\%\|SiO\-\%x\% catalyst system synthesized through sol\|gel method from palladium complex, ionic liquid, titanate and silicate esters was found for the oxidative carbonylation of amines. The catalyst efficiency was much higher than that reported in previous papers and the TOF number reached to 10 372 when catalyst 0.05%Pd\|4.6%BMImCl/TiO\-\%y\%\|SiO\-\%x\% was used. The usability of ionic liquid was the key point for preparation of this catalyst system because of its high dissolvability to palladium complex and affording appropriate micro\|environment for the reaction. The synergism among palladium complex, ionic liquid, titanate and silicate was the main reason for the high catalytic activity of the catalyst system. BET, AES and XRD were used to characterized the catalysts in detail.
基金supported by the Natural Science Foundation for Outstanding Young Scholars(No.41125018)the National Commonweal Project of the Ministry of Environmental Protection(No.201009057)
文摘Fifteen heavy-duty diesel vehicles were tested on chassis dynamometer by using typical heavy duty driving cycle and fuel economy cycle. The air from the exhaust was sampled by 2,4- dinitrophenyhydrazine cartridge and 23 carbonyl compounds were analyzed by high performance liquid chromatography. The average emission factor of carbonyls was 97.2 mg/km, higher than that of light-duty diesel vehicles and gasoline-powered vehicles. Formaldehyde, acetaldehyde, acetone and propionaidehyde were the species with the highest emission factors. Main influencing factors for carbonyl emissions were vehicle type, average speed and regulated emission standard, and the impact of vehicle loading was not evident in this study. National emission of carbonyls from diesel vehicles exhaust was calculated for China, 2011, based on both vehicle miles traveled and fuel consumption. Carbonyl emission of diesel vehicle was estimated to be 45.8 Gg, and was comparable to gasolinepowered vehicles （58.4 Gg）. The emissions of formaldehyde, acetaldehyde and acetone were 12.6, 6.9, 3.8 Gg, respectively. The ozone formation potential of carbonyls from diesel vehicles exhaust was 537 mg O3/km, higher than 497 mg O3/km of none-methane hydrocarbons emitted from diesel vehicles.
