论文部分内容阅读
Gaseous peroxides play important roles in atmospheric chemistry.To understand the pathways of the formation and removal of peroxides,atmospheric peroxide concentrations and their controlling factors were measured from 7:00 to 20:00 in September,October,and November 2013 at a heavily trafficked residential site in Beijing,China,with average concentrations of hydrogen peroxide (H2O2) and methyl hydroperoxide (MHP) at 0.55 ppb and 0.063 ppb,respectively.H2O2 concentrations were higher in the aftoon and lower in the ming and evening,while MHP concentrations did not exhibit a regular dial patt.Both H2O2 and MHP concentrations increased at dusk in most cases.Both peroxides displayed monthly variations with higher concentrations in September.These results suggested that photochemical activity was the main controlling factor on variations of H2O2 concentrations during the measurement period.Increasing concentrations of volatile organic compounds emitted by motor vehicles were important contributors to H2O2 and MHP enrichment.High levels of H2O2 and MHP concentrations which occurred during the measurement period probably resulted from the transport of a polluted air mass with high water vapor content passing over the Bohai Bay,China.