Near-infrared spectra of barium chloride bis(deuterium oxide) at 10 K. A local-mode approach

1991 ◽  
Vol 30 (13) ◽  
pp. 2772-2776 ◽  
Author(s):  
Paul J. McCarthy ◽  
Ian M. Walker
Keyword(s):  
Infrared Spectra ◽  
Near Infrared ◽  
Deuterium Oxide ◽  
Barium Chloride ◽  
Local Mode ◽  
Near Infrared Spectra

Near-infrared spectra of Ba(NO2)2•X2O (X = H,D) at 10 K. A local-mode approach

1997 ◽  
Vol 75 (8) ◽  
pp. 1099-1105 ◽  
Author(s):  
Ian M. Walker ◽  
Paul J. McCarthy
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Infrared Spectra ◽  
Near Infrared ◽  
Fermi Resonance ◽  
Strong Hydrogen Bond ◽  
Local Mode ◽  
Morse Oscillator ◽  
Near Infrared Spectra ◽  
Bifurcated Hydrogen Bond

The fundamental and overtone vibrational spectra of Ba(NO2)2•X2O (X=H,D) have been interpreted using the local mode model. The calculated parameters are consistent with the structure, which has one strong hydrogen bond and one weak bifurcated hydrogen bond. Evidence for Fermi resonance between stretch and bend features having similar energies is discussed. Evidence for the breakdown of the simple Morse oscillator model, which was quite successful for [Formula: see text] hydrogen bonds, is also presented. Keywords: overtone, spectra, near-infrared, hydrates, local-mode model.

Short-Wave near Infrared Spectra of Organic Liquids

1993 ◽  
Vol 1 (1) ◽  
pp. 13-23 ◽  
Author(s):  
Anthony S. Bonanno ◽  
Peter R. Griffiths
Keyword(s):  
Molecular Structure ◽  
Qualitative Analysis ◽  
Infrared Spectra ◽  
Near Infrared ◽  
Short Wave ◽  
Organic Liquids ◽  
Local Mode ◽  
Near Infrared Spectra ◽  
Vibrational Transitions

Multi-quanta vibrational transitions are discussed in terms of the local mode model in order to develop a better understanding of the features observed in the short-wave near infrared (700–1100 nm) spectra of organic liquids. It is demonstrated that the spectra of simple alkanes and alcohols exhibit local mode features, and that these features are characteristic of molecular structure and will, therefore, be useful for quantitative and qualitative analysis.

Short-Wavelength Near-Infrared Spectra of Sucrose, Glucose, and Fructose with Respect to Sugar Concentration and Temperature

2003 ◽  
Vol 57 (2) ◽  
pp. 139-145 ◽  
Author(s):  
Mirta Golic ◽  
Kerry Walsh ◽  
Peter Lawson
Keyword(s):  
Aqueous Solutions ◽  
Least Squares ◽  
Infrared Spectra ◽  
Short Wavelength ◽  
Near Infrared ◽  
Deuterium Oxide ◽  
Sugar Concentration ◽  
The Third ◽  
Near Infrared Spectra ◽  
Stretching Vibrations

Short-wavelength near-infrared (SW-NIR) (700–1100 nm) spectra of aqueous solutions of sucrose, d-glucose, and d-fructose were monitored with respect to change in temperature and sugar concentration. Sugar OH and CH related vibrations were identified by analysis of the spectra of sugar solutions in deuterium oxide (D2O), and of sucrose- d8 solutions in D2O. Absorption spectra were explained in terms of the second and third overtones of OH stretching vibrations and the third overtone of CH2 and CH stretchings. In deuterated solutions, CH and CH2 higher overtone vibration bands became apparent. The major spectral effect of decreased temperature or increased sugar concentration was a decrease in absorbance at 960 nm and an increase in absorbance at 984 nm, interpreted as an increase in the degree of H bonding. Partial least-squares (PLS) calibrations on sugar concentrations (with spectra collected at several sample temperatures) relied strongly on the 910 nm sugar CH related bands, whereas calibrations on temperature depended equally on all OH associated vibrations (750, 840, 960, and 985 nm).

Rapid Determining Contents of the Rhubarb Anthraquinones Compounds by Support Vector Machines Modeling based on Near Infrared Spectra

2020 ◽  
Vol 16 ◽  
Author(s):  
Linqi Liu ◽  
JInhua Luo ◽  
Chenxi Zhao ◽  
Bingxue Zhang ◽  
Wei Fan ◽  
...  
Keyword(s):  
Infrared Spectra ◽  
Near Infrared ◽  
Mean Squared Error ◽  
Rapid Determination ◽  
Partial Least Square ◽  
Least Square ◽  
Support Vector ◽  
Near Infrared Spectra ◽  
Aloe Emodin ◽  
Relative Differences

BACKGROUND: Measuring medicinal compounds to evaluate their quality and efficacy has been recognized as a useful approach in treatment. Rhubarb anthraquinones compounds (mainly including aloe-emodin, rhein, emodin, chrysophanol and physcion) are its main effective components as purgating drug. In the current Chinese Pharmacopoeia, the total anthraquinones content is designated as its quantitative quality and control index while the content of each compound has not been specified. METHODS: On the basis of forty rhubarb samples, the correlation models between the near infrared spectra and UPLC analysis data were constructed using support vector machine (SVM) and partial least square (PLS) methods according to Kennard and Stone algorithm for dividing the calibration/prediction datasets. Good models mean they have high correlation coefficients (R2) and low root mean squared error of prediction (RMSEP) values. RESULTS: The models constructed by SVM have much better performance than those by PLS methods. The SVM models have high R2 of 0.8951, 0.9738, 0.9849, 0.9779, 0.9411 and 0.9862 that correspond to aloe-emodin, rhein, emodin, chrysophanol, physcion and total anthraquinones contents, respectively. The corresponding RMSEPs are 0.3592, 0.4182, 0.4508, 0.7121, 0.8365 and 1.7910, respectively. 75% of the predicted results have relative differences being lower than 10%. As for rhein and total anthraquinones, all of the predicted results have relative differences being lower than 10%. CONCLUSION: The nonlinear models constructed by SVM showed good performances with predicted values close to the experimental values. This can perform the rapid determination of the main medicinal ingredients in rhubarb medicinal materials.

Discrimination of transgenic tomatoes based on visible/near-infrared spectra

2007 ◽  
Vol 584 (2) ◽  
pp. 379-384 ◽  
Author(s):  
Lijuan Xie ◽  
Yibin Ying ◽  
Tiejin Ying ◽  
Haiyan Yu ◽  
Xiaping Fu
Keyword(s):  
Infrared Spectra ◽  
Near Infrared ◽  
Near Infrared Spectra ◽  
Transgenic Tomatoes
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