澳门地区PM_(10)粒度分布的分形特征研究

The study on Fractal Dimensions of Size Distribution of Airborne Inhalable Particulates (PM_(10)) in Macao

采集澳门地区不同区域大气PM10样品,根据单颗粒图像分析方法分析了PM10的粒径分布,计算了各采样点PM10粒度分布的分形维数,分析讨论了PM10粒度分布分形维数的变化与粒度分布的关系,分析了粒度分布分形维数表征的澳门大气PM10不同采样点、不同季节的粒度整体分布及其影响因素之间的关系。结果表明,澳门地区PM10粒度分布的分形维数在2.05-3.95之间,夏季PM10的粒度分布分形维数（2.88）大于冬季（2.63）,表明夏季PM10的粒度普遍较冬季的细。同一季节不同区域大气PM10的粒度也有较大变化,夏季时,澳门岛的总体颗粒物、矿物颗粒和烟尘颗粒物的分形维数较氹仔岛的偏大,即澳门岛的颗粒物比氹仔岛偏细,而冬季则相反,冬季时,澳门岛的总体颗粒物、矿物颗粒和烟尘颗粒物的分形维数较氹仔岛的偏小。

PM_（10） samples were collected at different functional domains in Macao.Size distribution of PM_（10） were analyzed based on IA（Image Analysis） of single particle and the fractal dimensions of size distribution（FDSD） values of PM_（10） were calculated.The relationships between variations of FDSD and size distribution of PM_（10） were discussed and the variation of FDSD of PM_（10） at different sampling sites in different seasons and their influencing factors were further investigated.The results indicate that the FDSD of PM_（10） in Macao vary from 2.05 to 3.95,and the FDSD values in summer（2.88） are higher than those in winter（2.63）,which shows that the particles collected in summer is finer than those in winter.Size distribution of PM_（10） in different seasons showed a very different regional pattern.The summer samples showed that the FDSD values of the total particulates,mineral particulates and soot aggregates in the Macao Island are all higher than those in the Taipa Island,suggesting that the size of particles in the Macao Island is finer than that in the Taipa Island.In contrast to this,the winter samples showed that the FDSD values of the total particulates,mineral particulates and soot aggregates in the Macao Island are all lower than those in the Taipa Island.