Hyperspectral estimation of chlorophyll density in winter wheat using fractional-order derivative combined with machine learning - Yang, Chenbo; Feng, Meichen; Bai, Juan; Sun, Hui; Bi, Rutian; Song, Lifang; Wang, Chao; Zhao, Yu; Yang, Wude; Xiao, Lujie; Zhang, Meijun; Song, Xiaoyan (Frontiers in Plant Science, 2025)