This paper discusses three kinds of typical one-dimensional nonlinear equations coming from low permeability reservoir seepage models with different boundary conditions. The several finite difference methods including forward difference method and second central order difference quotient method are used for the respective discrete process of three models. With these difference methods, the discrete schemes of models are obtained. Then the corresponding nonlinear discrete equations are deduced. While dealing with the boundary condition, the mid-rectangle formula is used. Finally, integrated discrete equations of three nonlinear equations are formed. The results should be meaningful for the numerical simulation of non-Darcy flow model of the low-permeability oil wells.

According to the theory of simple linear regression model, this paper designed a lossless sensor data compression algorithm based on one-dimensional linear regression model. The algorithm computes the linear fitting values of sensor data’s differences and fitting residuals, which are input to a normal distribution entropy encoder to perform compression. Compared with two typical lossless compression algorithms, the proposed algorithm indicated better compression ratios.

<p class="p15">The main innovation of this paper includes two parts. One part is the discrete formulas of Thermo-hydro-mechanical (THM) coupling equations and another part is the discussion of the truncation errors based on the Taylor formula. There are many THM coupling problems in unsaturated soils, which are very important in both theoretical and engineering applications. The numerical computing of coupling equations is increasingly important. Considering the deformation of unsaturated soils skeleton, fluid flow and heat transfer, constitutive relationships of the THM coupled behavior are given. Then, the constitutive equations are derived and a closed problem is formed. The equations are dispersed by difference method and the truncation errors of the discrete formulas are given.</p>

This paper developments the research of improving the plasticity of low rank bituminous coal. The purpose is to improve the caking property of low rank bituminous coal and expand coking coal resources. The hydrothermal treatment, co-pyrolysis adding waste plastic and hydrogenation processing are chosen to process low rank bituminous coal. Several means including FTIR spectroscopy, thermogravimetric analysis, gas chromatographic(GC) and caking index are used to analyze the treated coal and generated gas products. The results show that the carboxyl groups of coal are removed after hydrothermal treatment, and the intensity of hydroxyl absorption increases. The oxygen-containing functional groups except hydroxyl groups of coal are removed after hydrogenation. The hydrogenation has obvious effects on the changes of coal structure. The reactivity and caking property of hydrotreated coal increases significantly, the indexes of coke quality of hydrotreated coal is measured to reach 16. The co-pyrolysis hydrogenation of plastic and coal results show that coal can prevent the thermal decomposition products of plastics from escaping. The caking index of hydrotreated coal with plastic is much same as that of hydrotreated coal. The addition of plastic in hydrogenation processing can not directly improve the coal plasticity.