Assessment of Contents and Health Impacts of Four Metals in Chongming Asparagus—Geographical and Seasonal Aspects,Components, acidification characteristics, and sources of atmospheric precipitation in Beijing from 1997 to 2020 - ScienceDirect,Characteristics and Sources of Single Particles in the Urban Liaocheng of North China during the Heating Period - Aerosol and Air Quality Research,Components, acidification characteristics, and sources of atmospheric precipitation in Beijing from 1997 to 2020 - ScienceDirect,Impacts of the “Coal to Gas” Policy on Rural Air VOC Level and Ozone Potentials in North China - Aerosol and Air Quality Research