[Determination of sodium by near infrared spectroscopy].

The research on near infrared spectroscopy of sodium in biological and medicine is significant. Sodion is the main component of electrolytes in human blood and electrolytes help maintain the body's acid-base balance. In the present paper the concentration of sodium was determined with the use of NIR spectra.

[On-line and in-situ spectral analysis of multicomponent gas mixture with same molecular group].

Aimed at the problem that Fourier transform infrared (FTIR) spectral analysis can't be used solely to analyze complex gas mxiture, in which there are many gas compositions, some compositions have same molecular group, and the concentrations of some compositions range greatly, in the present paper, a new spectral analysis method is proposed. For this method, the effects of gas temperature and gas pressure on the analysis result are taken into account, and feature variable extraction, recognition and correction of spectral disorder, robust modeling and multi-layer modeling with neural network (NN) are used to build gas mixture analysis models. At the end of this paper, on-line analysis of five alkane gases is taken as example to test the performance of the analysis method.

[A method for quantitative analysis system of alkane gaseous mixture with near infrared spectroscopy].

A method for online quantitative analysis system of alkane gaseous mixture with near infrared spectroscopy is described in the present paper. A single plane diffraction grating is used as the principal device in the monochromatic spectrum system. The key parameters of the monochromator were deduced and calculated in detail.