北京冬季大气颗粒物数浓度的粒径分布特征及来源

监测北京市冬季远郊区(密云)、交通道路(北四环)和生活区(清华大学)采样点的CO，NO，NO₂，SO₂等浓度，同时监测大气细颗粒物(FPs,粒径为0.1～2.5 μm)和超细颗粒物(UFPs，粒径<0.1 μm)的数浓度, 利用正交矩阵因子(PMF)法对FPs和UFPs数浓度的粒径分布特征和来源进行了研究. 结果表明:在远郊区采样点共有4个影响因子, 其中主因子1，4可能与长距离运移有关, 主因子2可能来自1 km外的村庄生活排放, 主因子3为附近铁路机车排放；在交通道路采样点共有3个影响因子, 其中主因子1，3可能均来自机动车排放, 主因子2来自燃煤污染；在生活区采样点共有3个影响因子, 其中，主因子1可能与机动车排放有关, 主因子2，3可能均来自燃煤排放. 

Size Distribution and Source Apportionment of Atmospheric Particle Number Concentration in Winter in Beijing

Based on monitoring records of CO, NO, NO₂, SO₂ and particle number concentration collected at a remote site, a roadside site and an urban residential site in Beijing in winter, the size distribution pattern of number concentration of fine particles (FPs, 0.1-2.5 μm) and ultrafine particles (UFPs, <0.1 μm), and their possible sources were examined using the EPA PMF model. At the remote site, four factors were identified. Factors 1 and 4 may be related to long distance transport, factor 2 to village emissions one kilometer away, and factor 3 to nearby locomotive emissions. At the roadside site, three factors were identified, of which factors 1 and 3 may be related to vehicle emissions and factor 2 to emissions from coal combustion. At the urban residential site, three factors were identified, ofwhich factor 1 may be related to vehicle emissions and factors 2 and 3 to emissions from coal combustion.