【摘要】 用近红外透射光谱技术和偏最小二乘法建立甘蔗初压汁锤度的定量分析模型。用多元散射校正和Savitzky-Golay平滑化方法对原谱、一阶导数谱和二阶导数谱进行预处理。选取400—1100nm、1100—1400nm、1550—1850nm、2100—2350nm以及全谱(400—2500nm)5个波段,每个波段分别采用原光谱、一阶导数谱、二阶导数谱。同时调整Savitzky-Golay平滑点数和PLS因子数,通过多次PLS数值实验比较,按照预测效果确定每个模型的最优平滑点数、因子数,再从中选优。结果表明,采用二阶导数谱的1550-1850nm波段的定标效果最好,模型的预测相关系数、预测均方根偏差、相对预测均方根偏差分别为0.896,0.406,1.95%。1550—1850nm波段可以代替全谱波段得到好的定标效果,为设计小型专用近红外分析仪器提供依据。更多还原

【Abstract】 The calibration models for brix in sugarcane initial-pressed juice were established based on near infrared transmission spectroscopy technology and PLS method.The original spectra,the first derivative spectra and the second derivative spectra were pretreated by multiplicative scatter correction method and Savitzky-Golay smoothing method.The following 5 wave bands were selected:400—1100nm,1100—1400nm,1550—1850nm,2100—2350nm and the whole region(400—2500nm),and the original spectra,the first derivative spectra and the second derivative spectra were adopted in each band respectively.By adjusting Savitzky-Golay smoothing point number and the PLS factor number simultaneously,compared with many PLS computational experiments,got optimal smoothing point number and factor number for each model according to the prediction effect,and then selected the best one as the second derivative spectra in the 1550—1850nm and prediction correlation coefficient,RMSEP and RRMSEP for the corresponding model are 0.896,0.406,1.95%,respectively.The 1550—1850 nm can replace the whole band and get good calibration effect,which provide base for designing minitype special near infrared content analyzer.更多还原