Light absorption of black carbon and brown carbon in winter in North China Plain: comparisons between urban and rural sites

Jiaxing Sun, Conghui Xie, Weiqi Xu, Chun Chen, Nan Ma, Wanyun Xu, Lu Lei, Zhijie Li, Yao He, Yanmei Qiu, Qingqing Wang, Xiaole Pan, Hang Su, Yafang Cheng, Cheng Wu, Pingqing Fu, Zifa Wang, Yele Sun