中文摘要：

2010年1月14日及10月16—17日，在位于上海西北郊的上海应用物理研究所分粒径采集了大气颗粒物，并于2010年10月19—21日进行了采集样品和三种标准物质（草酸、蔗糖、石墨）的X射线近边吸收精细结构（NEXAFS）谱分析。发现在不同粒径及不同时间段（如昼、夜）的新采集的大气颗粒物中的C（1s）NEXAFS谱存在明显差异，主要表现在羧基．COOH及碳酸盐类／羰基C=O基团成分的不同；然而在1月14日不同时间段采集并在冰箱中保存了9个月的分粒径的大气颗粒物样品的C（1s）NEXAFS谱中却无此差异，表明在样品的存贮过程中可能存在含碳物质的衰减和再平衡反应。

英文摘要：

Carbon chemical species in size-resolved airborne particulate matters collected on January 14 and October 16-17, 2010 at S1NAP, a suburban spot in northwest Shanghai, and in three standard samples （oxalic acid, sucrose and graphite）, were characterized on October 19-21, 2010 with the near-edge X-ray absorption fine structure （NEXAFS） spectroscopy. The C（ls） NEXAFS spectra differ distinctly among the freshly collected particulate matters of different size ranges and different collection hours, i.e. in day time or at night. The difference is mainly the asymmetrical distribution of carboxyl -COOH, carbonate and carbonyl C =O components. However, this was not observed among the C（ls） NEXAFS spectra of particulate matters collected in different hours of January 14 and kept refrigerated for 9 months, suggesting possible decay or re-equilibrium of the carbon chemical species in the sample storage.