根据分子图的信息计算出柴油中各种烃类分子的ＮＣ指数、Ｊ指数、Ｐ３指数和ｆ指数，并将这些反映分子结构信息的指数与柴油中烃类的十六烷值进行多项式拟合。在所得拟合式中，链烷烃拟合式的相关系数Ｒ２为０．９５８，剩余标准差Ｓ为６．１３６；环状烃拟合式的相关系数Ｒ２为０．９９１，剩余标准差Ｓ为２．０５３ Calculate the NC index, J index, P3 index and f index of various hydrocarbon molecules in diesel oil according to the information of the molecular chart, and carry out the polynomial fitting of the indexes reflecting the molecular structure information with the cetane number of the hydrocarbons in the diesel oil . In the fitted formula, the correlation coefficient of paraffin R2 was 0.958, the residual standard deviation S was 6.136; the correlation coefficient R2 of the cyclic hydrocarbon was 0.991, the residual standard deviation S was 2.053