Quantifying secondary organic aerosols and O3 formation drivers in North China: Comprehensive method combining random forest, positive matrix factorization, and observation-based model - Qi Huang; Tianshuai Li; Tao Zhang; Yuan Fang; Feijie Gong; Yifan Li; Peng Xu; Tianqi Zhang; Lingxiao Yang; Wenxing Wang (Journal of Environmental Sciences, 2026)