Characteristics and sources of amine-containing particles in the urban atmosphere of Liaocheng, a seriously polluted city in North China during the COVID-19 outbreak.

As an important tracer of primary combustion emissions ( Zhang et al., 2021 ), CO presented a decreasing trend similar to that of PM 2.5 concentration throughout the LCD ( Fig. 1 ).

also in 47,180 other papers

S7 , the fraction of BB particle type showed an increasing trend from 4.2 % during the pre-LCD to 7.0 % during the LCD to 12.1 % during the post-LCD.

also in 63,971 other papers

The concentrations of NH 4 + showed a slightly increasing trend from the beginning (7.7 μg m −3 ) to the end (10.6 μg m −3 ) of Fog 1.

also in 801 other papers