With the continue improvement of atmospheric environment in Mega-City,the atmospheric conditions of the surrounding satellite city has received wide public concern.In the present study,both the number and mass weighted size distributions of fine particles(0.03-2.50 μm) in Taicang,a satellite city surrounding Shanghai,were online determined by ELPI.The source analysis was conducted by using mass concentrations and enriched factors of 15 trace elements(Ca,Ti,V,Cr,Mn,Fe,Co,Ni,Cu,Zn,As,Se,Sr,Cd,Pb) in the PM2.5.Results show that the concentrat...