Weakening synergies in carbon and air pollution co-control necessitate robust structural transitions in China's transportation sector. - Qi, Zhulin; Zheng, Yixuan; Cao, Wenxin; Liu, Yuxi; Li, Xin; Fei, Yueying; Liu, Shigan; Jiang, Fangming; Chen, Chuchu; Feng, Yueyi (National Science Review, 2025)