烤烟均质化指标概念及计算模型

The Concept and Calculation Model of Flue-cured Tobacco Homogeneity Index

为了对烤烟均质性进行定量度量,利用变异系数和倒S型函数模型,提出了均质性指数的概念(Homogeneousness,H)。利用SAS软件建立了分段模型和倒S型函数模型,以云南某地烟叶化学成分为例,计算了空间和时间维度的H值。结果表明,分段模型3段的决定系数分别为0.9989,0.9990和0.9328,均达到了1%显著水平;倒S型函数模型的决定系数为0.9978。前者计算精度更高,但计算过程略为繁琐。在时间维度上,某县某乡镇烟叶在2015年~2019年间H值(倒S曲线法)分别为:烟碱92.00,总糖94.61,还原糖91.59,总氮93.82,钾92.92,氯67.39,糖碱比81.74,氮碱比94.29,两糖比94.76,钾氯比60.76,化学成分总的H值为86.70。在空间维度上,烟叶化学成分H值某州、某县和某烟站分别为74.18、72.30和90.88。该模型在国内外属于首创,简单、鲁棒、实用性强、能够很好地用来度量烟叶的均质化程度。

Concept of homogeneity index(Homogeneousness,H)is proposed by using the coefficient of variation and the inverted S-type model,so that homogenization of tobacco leaf can be quantified scientifically.A segmented model and an inverted S-type model were established using SAS system.H-values of spatial and time dimensions were calculated by using the chemical composition of the tobacco leaf from Wenshan prefecture in Yunnan province.The results showed that the R2 for the segmented model were 0.9989,0.9990,and 0.9328 for each of the 3 segments,respectively,with a 1%significant level,while the R2 for the inverted Model S was 0.9978.The former had higher accuracy but the calculation process was slightly cumbersome.In term of timeline,the H index(inverted S curve method)for tobacco leaves from a township,Yanshan county between 2015 and 2019 was:nicotine 92.00,total sugar 94.61,reduced sugar 91.59,total nitrogen 93.82,potassium 92.92,chlorine 67.39,(total sugar)/nicotine 81.74,nitrogen/nicotine 94.29,(reduced sugar)/(total sugar)94.76,K/Cl 60.76,respectively.The H index for chemical composition is 86.70.In space dimension,the H index for leaf chemical composition is 74.18,72.30,and 90.88 for Wenshan prefecture,Yanshan county,and Pingyuan township,respectively.This H index is proposed and tested first time in the world,which is simple,robust,practical,and can readily measure the degree of homogenization of tobacco leaves.