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Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
Box plot of PM10, SO2, NO2, Temperature and Relative humidity in Jinchang city, Gansu Province, China, 2011–2015. (× represent the 5th/95th percentiles of each value).