中文摘要：

为了探讨西安市冬季大气亚微米颗粒物的污染水平及化学组成，2006年12月每天收集西安大气亚微米颗粒物（PM1.0）样品，并对PM1.0的质量浓度及其其中的11种水溶性离子、元素碳（EC）和有机碳（OC）及8个碳组分进行了分析．结果显示：西安市冬季大气PM1.0的平均质量浓度为149．7μg·m^-3分析的11种阴、阳离子（Na^＋、NH4^＋、K^＋、Mg^2＋、Ca^2＋、F^-、Cl^-、Br^-、NO2^-、NO3^-和SO4^2-）的质量浓度占到PM1.0的46％，表明水溶性组分是大气亚微米颗粒物的主要组成之一；OC的质量浓度（ρ（OC）=（23．7±10．27）μg·m^-3）明显高于EC的（（ρ（EC）=（4．6±1．8）μg·m^-3），碳气溶胶的平均质量浓度为42．5μg·m^-3，占到PM1.0质量浓度的28．4％；对8个碳组分的因子分析结果显示，燃煤及汽油车排放、柴油车排放和生物质燃烧对碳颗粒的贡献分别为45．3％、24．2％和23．5%．

英文摘要：

The objectives of this research were to characterize the chemical composition of submicron particles （PM1.0） over Xi＇an during winter and to identify their sources. Daily aerosol samples （PM1.0） were collected continuously from Dec. 1st to Jan. 1st, 2006, and the concentrations of 11 water-soluble ions （Na^＋, NH4^＋, K^＋, Mg2^＋, Ca2^＋, F^-, Cl^- , Br^-, NO2^-, NO3^-, and SO4^2- ）, and elemental carbon （EC） and organic carbon （OC） were determined in the filter samples. The mean PM1.0 mass concentration was 149.7μg m^-3. The total concentrations of 11 ions were 46% of PM1.0 mass concentration, indicating that water-soluble ions were the major compo- nents of submicron particles. The average OC and EC concentrations were 23.7±10.27 μg m^-3 and 4.6±1.8μg m^-3, respectively, an important contributor to the regional carbonaceous aerosol. Factor analysis on the eight carbon fractions shows that 45.3 % of total carbon in winter was attributed to coal combustion and gasoline automobile exhaust, 24. 2% to diesel automobile exhaust, and 23.5 % to biomass burning.