To investigate the effects of biomass burning and photochemical oxidation on the black carbon (BC) mixing state and light absorption, a tandem centrifugal particle mass analyzer (CPMA) and single-particle soot photometer (SP2) system was used to measure ambient fine particulate BC during EXPLORE-YRD 2018 campaign (EXPeriment on the eLucidation of the atmospheric Oxidation capacity and aerosol foRmation, and their Effects in Yangtze River Delta). The mass ratio (M_R) of the non-BC coating to BC core, a morphology-independent parameter to quantify the mixing state of BC-containing aerosols, is derived. Two types of periods were identified, namely non-significant biomass-burning period (NB), and enhanced biomass burning period (EB). The M_R was higher during EB (2.3 ± 0.5), compared with during the NB (2.0 ± 0.5). M_R showed bimodal diurnal variation with peaks in the early morning and early afternoon, mainly due to the biomass burning and photochemical processes, respectively. The light-absorbing enhancement ranged from 1.0 to 1.19 when M_R was from 1.4 to 3.4. The relationship of rBC mixing state and its optical properties was parameterized, which can further be used in the regional model.

为了研究生物质燃烧和光化学氧化对黑碳（BC）混合状态和光吸收的影响，使用串联离心式颗粒质量分析仪（CPMA）和单颗粒烟灰光度计（SP2）系统测量环境中的细颗粒BC期间探索-长三角2018运动（EXP上的电子eriment大号大气的ucidation ö xidation容量和气溶胶FO ř mation，和它们的è长三角ffects）。质量比（M _R）得出非BC涂层与BC核心之间的关系，得出一个与形态无关的参数来量化含BC气溶胶的混合状态。确定了两种类型的时期，即非重要的生物质燃烧期（NB）和增强的生物质燃烧期（EB）。与NB期间（2.0±0.5）相比，EB期间的M _R较高（2.3±0.5）。M _R显示双峰日变化，在清晨和午后出现峰值，主要是由于生物质燃烧和光化学过程。当M _R为1.4至3.4时，光吸收增强范围为1.0至1.19 。参数化了rBC混合态与其光学性质之间的关系，可进一步用于区域模型。