%0 Journal Article %T Predicting nickel concentration in soil using fractional-order derivative and visible-near-infrared spectroscopy indices %A Cao, Jianfei %A Liu, Wei %A Feng, Yongyu %A Liu, Jianhua %A Ni, Yuanlong %J PLoS ONE %V 19 %N 8 %D 2024-08-01 %I Public Library of Science %~ DeepDyve