He key fuel kinds utilized by motor cars. The transportation business may be the biggest customers of diesel [14], gasoline and kerosene and can also be considered to be the main reason why liquid sources in EBC dominate all through the year [35]. Xuzhou is often a extensive transportation hub in China exactly where quite a few big highway lines intersect. According to the Xuzhou Bureau of Statistics, at the end of 2016, Xuzhou had a total of 1.367 million motor vehicles having a transportation volume of 378.96 million tons. More than a reasonably lengthy time frame, EBC aerosols generated by vehicle transportation accounted for the major supply. Most solid fuels come from the burning of coal and biomass. In China, farmers usually burn agricultural wastes which include straw, wheat straw, and corn straw. The emissions resulting from the open burning of biomass account for around 7 of China’s total equivalent black carbon emissions [36]. Through the heating season, Xuzhou, as an important coal production base in East China, has excellent output and consumption. In line with the Xuzhou Bureau of Statistics, the annual output reached 13.42 million tons in 2016, and the complete consumption was 23.48 million tons of standard coal, of which 7.42 million tons of common coal was consumed by thermal production and provide, accounting for 20.84 in the annual consumption. Xuzhou’s extensive consumption in 2015 was 23.52 million tons of standard coal, and thermal production and supply consumed 7.69 million tons of normal coal, accounting for 32.64 of the annual consumption. Thermal central heating is only utilised in the autumn and winter. On the a single hand, urban collective heating demands thermal energy stations that burn a big quantity of coal as a heat source. However, men and women in unheated areas or rural regions burn straw and wood furthermore to coal for heating, resulting in strong sources that occupy the main Hematoporphyrin Data Sheet position of EBC sources throughout the heating season. A different study noted that the unit size of greater than 150 energy plants is 100 MW, and 200 cement plants and 10 big steel plants are located along northwestern Anhui [37]. This area is constant with the backward clustering shown in Figure 8a, showing the orientation on the source concentration. 4.3. Difference in between EBC and BrC in the Heating and Nonheating Seasons Within this paper, the proportion of brown carbon in EBC was significantly larger within the heating season than in the nonheating season, which is consistent using the findings in northern Chinese cities. In the study in Beijing, the average annual abundance of BrC was 0.82 0.44 /m3 . The concentration reached a peak of two.31 0.44 /m3 in the winter, followed by autumn, spring and summer. Meanwhile, the absorption of BrC/EBC at the wavelength range of 35050 nm was highest within the winter (21.78 three.56 ), followed by autumn (11.53 five.29 ), spring (6.38 four.06 ) and summer time (four.26 2.57 ). Seasonal variation in BrC concentration and absorption proportion was consistent with heating time [38]. This feature varies widely in terms of heating or not. A study in the seasonal occurrence frequencies of distinct aerosol models in three regions of China identified that Beijing and Lanzhou, which possess a heating tradition, possess a substantially larger frequency of BrC occurrence in autumn and winter than in spring and summer, although Taihu Lake in southern Jiangsu includes a decrease occurrence probability, as shown in Table three [39].Atmosphere 2021, 12,14 ofTable 3. Proportion of BrC in EBC in d.