The submicron particulate matter(PM_(1))and fine particulate matter(PM_(2.5))are very important due to their greater adverse impacts on the natural environment and human health.In this study,the daily PM_(1) and PM_(2...The submicron particulate matter(PM_(1))and fine particulate matter(PM_(2.5))are very important due to their greater adverse impacts on the natural environment and human health.In this study,the daily PM_(1) and PM_(2.5) samples were collected during early summer 2018 at a sub-urban site in the urban-industrial port city of Tianjin,China.The collected samples were analyzed for the carbonaceous fractions,inorganic ions,elemental species,and specific marker sugar species.The chemical characterization of PM_(1) and PM_(2.5) was based on their concentrations,compositions,and characteristic ratios(PM_(1)/PM_(2.5),AE/CE,NO3^-/SO4^2-,OC/EC,SOC/OC,OM/TCA,K^+/EC,levoglucosan/K^+,V/Cu,and V/Ni).The average concentrations of PM_(1) and PM_(2.5) were 32.4μg/m and 53.3μg/m^3,and PM_(1) constituted 63%of PM_(2.5) on average.The source apportionment of PM_(1) and PM_(2.5) by positive matrix factorization(PMF)model indicated the main sources of secondary aerosols(25%and 34%),biomass burning(17%and 20%),traffic emission(20%and 14%),and coal combustion(17%and 14%).The biomass burning factor involved agricultural fertilization and waste incineration.The biomass burning and primary biogenic contributions were determined by specific marker sugar species.The anthropogenic sources(combustion,secondary particle formation,etc)contributed significantly to PM_(1) and PM_(2.5),and the natural sources were more evident in PM_(2.5).This work significantly contributes to the chemical characterization and source apportionment of PM_(1) and PM_(2.5) in near-port cities influenced by the diverse sources.展开更多
The authors regret'In the acknowledgments of this manuscript,the Nos.51678035 and 51478041 of the National NaturalScience Foundation of China are wrong.The correct Nos.are 51678053 and 51478041'.The authors wo...The authors regret'In the acknowledgments of this manuscript,the Nos.51678035 and 51478041 of the National NaturalScience Foundation of China are wrong.The correct Nos.are 51678053 and 51478041'.The authors would like to apologize for any inconvenience caused.展开更多
In this study,the black carbon (BC) measurements in the atmosphere of Nanjing,China were continuously conducted from 2015 to 2018 using a Model AE-33 aethalometer.By combining dataset of PM_(2.5),PM_(10),CO,NO_2,SO_2,...In this study,the black carbon (BC) measurements in the atmosphere of Nanjing,China were continuously conducted from 2015 to 2018 using a Model AE-33 aethalometer.By combining dataset of PM_(2.5),PM_(10),CO,NO_2,SO_2,O_3 and meteorological parameters,the temporal variations and the source apportionment of BC were given in this study.The results showed that the PM_(2.5) mass concentrations decreased in Nanjing,with an average annual rate of variation of 6.50μg/(m^3·year).Differently,the annual average concentrations of BC increased with an average annual variation rate of 214.71 ng/(m^3·year).The seasonal variations showed the pattern of BC mass concentrations in winter>autumn>spring>summer.The diurnal variations of BC mass concentrations showed a double-peak in all four seasons.The first peak occurred at approximately 7:00 in spring,summer and autumn and around 8:00 in winter.The second peak took place after 18:00.The average AAE (absorption ?ngstr?m exponent) was 1.26 with a maximum of 1.35 during wintertime and the lowest(1.12) during summertime.In addition,the AAE was smaller in the daytime than that at night,with a minimum occurring between 13:00 and 14:00.BC and visibility show a good power-function relationship at different humidity levels.The average values of the visibility thresholds of the BC mass concentrations in spring,summer,autumn and winter were 1.326,5.522,1.340 and 0.708μg/m^3,respectively.The greater the relative humidity,the smaller the visibility threshold for the BC mass concentrations was.展开更多
The hydroxyl radical(·OH)has a crucial function in the oxidation and removal of many atmospheric compounds that are harmful to health.Nevertheless,high reactivity,low atmospheric abundance,determination of hydrox...The hydroxyl radical(·OH)has a crucial function in the oxidation and removal of many atmospheric compounds that are harmful to health.Nevertheless,high reactivity,low atmospheric abundance,determination of hydroxyl,and hydroperoxyl radical’s quantity is very difficult.In the atmosphere and troposphere,hydroperoxyl radicals(HO_(2))are closely demanded in the chemical oxidation of the troposphere.But advances in technology have allowed researchers to improve the determination methods on the research of free radicals through some spectroscopic techniques.So far,several methods such as laser-induced fluorescence(LIF),high-performance liquid chromatography(HPLC),and chemical ionization mass spectroscopy have been identified and mostly used in determining the quantity of hydroxyl and hydroperoxyl radicals.In this systematic review,we have advised the use of scavenger as an advance for further researchers to circumvent some of these problems caused by free radicals.The primary goal of this review is to deepen our understanding of the functions of the most critical free radical(·OH,HO_(2))and also understand the currently used methods to quantify them in the atmosphere and troposphere.展开更多
基金the Tianjin Science and Technology Program(No.18ZXSZSF00160)the Fundamental Research Funds for the Central Universities of China(Nos.ZB19500210 and ZB19000804)。
文摘The submicron particulate matter(PM_(1))and fine particulate matter(PM_(2.5))are very important due to their greater adverse impacts on the natural environment and human health.In this study,the daily PM_(1) and PM_(2.5) samples were collected during early summer 2018 at a sub-urban site in the urban-industrial port city of Tianjin,China.The collected samples were analyzed for the carbonaceous fractions,inorganic ions,elemental species,and specific marker sugar species.The chemical characterization of PM_(1) and PM_(2.5) was based on their concentrations,compositions,and characteristic ratios(PM_(1)/PM_(2.5),AE/CE,NO3^-/SO4^2-,OC/EC,SOC/OC,OM/TCA,K^+/EC,levoglucosan/K^+,V/Cu,and V/Ni).The average concentrations of PM_(1) and PM_(2.5) were 32.4μg/m and 53.3μg/m^3,and PM_(1) constituted 63%of PM_(2.5) on average.The source apportionment of PM_(1) and PM_(2.5) by positive matrix factorization(PMF)model indicated the main sources of secondary aerosols(25%and 34%),biomass burning(17%and 20%),traffic emission(20%and 14%),and coal combustion(17%and 14%).The biomass burning factor involved agricultural fertilization and waste incineration.The biomass burning and primary biogenic contributions were determined by specific marker sugar species.The anthropogenic sources(combustion,secondary particle formation,etc)contributed significantly to PM_(1) and PM_(2.5),and the natural sources were more evident in PM_(2.5).This work significantly contributes to the chemical characterization and source apportionment of PM_(1) and PM_(2.5) in near-port cities influenced by the diverse sources.
文摘The authors regret'In the acknowledgments of this manuscript,the Nos.51678035 and 51478041 of the National NaturalScience Foundation of China are wrong.The correct Nos.are 51678053 and 51478041'.The authors would like to apologize for any inconvenience caused.
基金supported by the National Natural Science Foundation of China (Nos.91644224 and 41805096)the special fund of State Key Joint Laboratory of Environment Simulation and Pollution Control (No.19K03ESPCP)+1 种基金the Natural Science Foundation of Jiangsu Province (No.BK20180801)the Natural Science Research Project for Universities of Jiangsu Province,China (No.18KJB170011)。
文摘In this study,the black carbon (BC) measurements in the atmosphere of Nanjing,China were continuously conducted from 2015 to 2018 using a Model AE-33 aethalometer.By combining dataset of PM_(2.5),PM_(10),CO,NO_2,SO_2,O_3 and meteorological parameters,the temporal variations and the source apportionment of BC were given in this study.The results showed that the PM_(2.5) mass concentrations decreased in Nanjing,with an average annual rate of variation of 6.50μg/(m^3·year).Differently,the annual average concentrations of BC increased with an average annual variation rate of 214.71 ng/(m^3·year).The seasonal variations showed the pattern of BC mass concentrations in winter>autumn>spring>summer.The diurnal variations of BC mass concentrations showed a double-peak in all four seasons.The first peak occurred at approximately 7:00 in spring,summer and autumn and around 8:00 in winter.The second peak took place after 18:00.The average AAE (absorption ?ngstr?m exponent) was 1.26 with a maximum of 1.35 during wintertime and the lowest(1.12) during summertime.In addition,the AAE was smaller in the daytime than that at night,with a minimum occurring between 13:00 and 14:00.BC and visibility show a good power-function relationship at different humidity levels.The average values of the visibility thresholds of the BC mass concentrations in spring,summer,autumn and winter were 1.326,5.522,1.340 and 0.708μg/m^3,respectively.The greater the relative humidity,the smaller the visibility threshold for the BC mass concentrations was.
基金the National Key R&D Program of China(No.2016YFC0202900)the National Natural Science Foundation of China(Nos.21567015 and 21407072)+5 种基金the West Light Foundation of The Chinese Academy of Sciences(2019)special fund of State Key Joint Laboratory of Environment Simulation and Pollution Control(No.20K03ESPCP)the Natural Science Foundation of Gansu Province(Nos.18JR3RA079 and 17JR5RA109)the Project of Food and Drug Administration of Gansu Province(No.2018GSFDA014)the Gansu Provincial Party Committee Young Creative Talents(No.Ganzutongzi[2017]121)the Hongliu Science Fund for Distinguished Young Scholars(2018)。
文摘The hydroxyl radical(·OH)has a crucial function in the oxidation and removal of many atmospheric compounds that are harmful to health.Nevertheless,high reactivity,low atmospheric abundance,determination of hydroxyl,and hydroperoxyl radical’s quantity is very difficult.In the atmosphere and troposphere,hydroperoxyl radicals(HO_(2))are closely demanded in the chemical oxidation of the troposphere.But advances in technology have allowed researchers to improve the determination methods on the research of free radicals through some spectroscopic techniques.So far,several methods such as laser-induced fluorescence(LIF),high-performance liquid chromatography(HPLC),and chemical ionization mass spectroscopy have been identified and mostly used in determining the quantity of hydroxyl and hydroperoxyl radicals.In this systematic review,we have advised the use of scavenger as an advance for further researchers to circumvent some of these problems caused by free radicals.The primary goal of this review is to deepen our understanding of the functions of the most critical free radical(·OH,HO_(2))and also understand the currently used methods to quantify them in the atmosphere and troposphere.