An outlier detection method is proposed for near-infrared spectral analysis. The underlying philosophy of the method is that,in random test(Monte Carlo) cross-validation,the probability of outliers presenting in good ...An outlier detection method is proposed for near-infrared spectral analysis. The underlying philosophy of the method is that,in random test(Monte Carlo) cross-validation,the probability of outliers presenting in good models with smaller prediction residual error sum of squares(PRESS) or in bad models with larger PRESS should be obviously different from normal samples. The method builds a large number of PLS models by using random test cross-validation at first,then the models are sorted by the PRESS,and at last the outliers are recognized according to the accumulative probability of each sample in the sorted models. For validation of the proposed method,four data sets,including three published data sets and a large data set of tobacco lamina,were investigated. The proposed method was proved to be highly efficient and veracious compared with the conventional leave-one-out(LOO) cross validation method.展开更多
3,4-Bis（4＇-aminofurazano-3＇）furoxan（DATF）, one of a new generation of high energy density materials, shows lots of interesting properties such as lower sensitivity, excellent thermal stability and superior deton...3,4-Bis（4＇-aminofurazano-3＇）furoxan（DATF）, one of a new generation of high energy density materials, shows lots of interesting properties such as lower sensitivity, excellent thermal stability and superior detonation perfor- mance in chemistry and physics. In this paper, on-line infrared（IR） spectroscopy was used to monitor the synthesis process of DATF. The concentration profiles and IR spectra of the components were determined by analyzing the IR data via principal component analysis（PCA）, evolving factor analysis（EFA） and multivariate curve resolution-alternating least squares（MCR-ALS）. The geometric configurations of reactant, intermediates and product were optimized with the density functional theory（DFT） at B3LYP/6-3 l＋G（d, p） level. Their vibrational frequencies and IR spectra were obtained on the basis of vibrational analysis. The result obtained by the chemometric resolution methods agreed well with that obtained by quantum chemical calculation method, which demonstrated the reliability of the proposed chemometric resolution methods. The unstable intermediate 3-amino-4-oxycyanofurazan（AOF） was confirmed via comparing the IR spectra resloved by chemometric resolution methods with those calculated by B3LYP/6-3 l＋G（d,p） and analyzed by MCR-ALS. Finally, the possible synthesis mechanism of DATF was deduced by analyzing the above IR spectra.展开更多
基金Supported by the National Natural Science Foundation of China (Grant Nos. 20575031 and 20775036)the Ph.D. Programs Foundation of Ministry of Education (MOE) of China (Grant No. 20050055001)
文摘An outlier detection method is proposed for near-infrared spectral analysis. The underlying philosophy of the method is that,in random test(Monte Carlo) cross-validation,the probability of outliers presenting in good models with smaller prediction residual error sum of squares(PRESS) or in bad models with larger PRESS should be obviously different from normal samples. The method builds a large number of PLS models by using random test cross-validation at first,then the models are sorted by the PRESS,and at last the outliers are recognized according to the accumulative probability of each sample in the sorted models. For validation of the proposed method,four data sets,including three published data sets and a large data set of tobacco lamina,were investigated. The proposed method was proved to be highly efficient and veracious compared with the conventional leave-one-out(LOO) cross validation method.
基金Supported by the National Natural Science Foundation of China（No.21175106） and the Specialized Research Fund for the Doctoral Program of Higher Education, China（No.20126101110019）.
文摘3,4-Bis（4＇-aminofurazano-3＇）furoxan（DATF）, one of a new generation of high energy density materials, shows lots of interesting properties such as lower sensitivity, excellent thermal stability and superior detonation perfor- mance in chemistry and physics. In this paper, on-line infrared（IR） spectroscopy was used to monitor the synthesis process of DATF. The concentration profiles and IR spectra of the components were determined by analyzing the IR data via principal component analysis（PCA）, evolving factor analysis（EFA） and multivariate curve resolution-alternating least squares（MCR-ALS）. The geometric configurations of reactant, intermediates and product were optimized with the density functional theory（DFT） at B3LYP/6-3 l＋G（d, p） level. Their vibrational frequencies and IR spectra were obtained on the basis of vibrational analysis. The result obtained by the chemometric resolution methods agreed well with that obtained by quantum chemical calculation method, which demonstrated the reliability of the proposed chemometric resolution methods. The unstable intermediate 3-amino-4-oxycyanofurazan（AOF） was confirmed via comparing the IR spectra resloved by chemometric resolution methods with those calculated by B3LYP/6-3 l＋G（d,p） and analyzed by MCR-ALS. Finally, the possible synthesis mechanism of DATF was deduced by analyzing the above IR spectra.
