Heterogeneous Media Optical And Infrared Spectroscopic Properties

In nature, most of the primitive mediums are inhomogeneous materials. Moreover, some artificial mediums are also inhomogeneous such as synthetic, polycrystalline, nanostructured materials, etc. The light scattering theories and the optical properties of inhomogeneous materials are significant because light will be scattered or absorbed when spreading in inhomogeneous materials, which makes them valuable for the research and applications in geology, astronomy, chemistry, engineering and other fields.This thesis, based on the scattering theory, synthesizes the optical and spectral properties of inhomogeneous materials into two methods, one is forward method and the other is reverse method. We research the powders of hydrocarbon source rocks, which are primitive materials, quantitatively and qualitatively, and analyze the thin section of oiled rocks in micro scale with micro-infrared imaging spectrum technique. The main contents are as follows.1. Research two-flux and modified two-flux theory and discuss the forward method and the inverse method for two theories respectively. Compute the scattering coefficient and the absorption coefficient of the powder samples using the reverse method of modified two-flux theory by MATLAB, analyze the formative physical mechanism and characteristics of infrared diffuse reflection spectrum technique, and explain the selection of parameters and the theoretic basis of quantitative analysis by diffuse reflection spectrum.2. Measure the infrared diffuse reflection spectrums of powders of hydrocarbon source rocks by FT IR spectrometer. Quantitatively analyze the hydrocarbon generating potential. Discuss the principle and limitations of Ganz's A factor and advantage of the multivariate analysis. Explain the reasons selecting 2800cm^-1-3100cm^-1 wave band for quantitative analysis and build a steady, accurate quantitative analysis model with multivariate analysis.3. Scattering has always been considered as a disturbance in the quantitative analysis. Intensity of scattering is determined by geometrical parameters of materials, for instance particle size etc. In order to establish an ideal quantitative analysis model, we should choose particles in a suitable size. Disturbance of scattering can be effectively eliminated with Chemometrics. However, information of low frequency denoting scattering of the spectrums can be extracted by DWT. With this information, we can create an excellent linear regression model to accurately analyze the particle size which has important applications to pharmacy, cement and other industries.4. Expound the basic principles and the development of imaging spectrum. Analyze the thin section of oiled rocks to get the space distributions of various components, especially the minim organic material by micro-ATR and transmission method respectively with micro-infrared imaging spectrum technique. Moreover, for the first time, we applied fusion technique to imaging processing, which makes results possess high spectral resolution and spatial resolution at the same time.