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Four sets of Li 2 O-ZnO-Al 2 O 3 -SiO 2 (LZAS) glass-ceramics containing different content of fluorine were fabricated. With CaF 2 content increasing, the glass transition temperature (T g ) and crystallization temperature (T c1 , or T c2 ) decreased as differential scanning calorimetry results showed; this phenomenon could be explained based on the Fourier-transformed infrared spectra analysis. X-ray diffraction (XRD) results indicated that CaF 2 did influence the crystallization temperatures of some crystal phase in the LZAS glass-ceramics, the transformations from glass to b-quartz ss solid solution and b-quartz ss to b-spodumene occurred at lower temperatures, and the decrease could reach to 80°C. According to the scanning electron microscope analysis, the addition of F À ions can contribute to a microstructure with higher crystallinity and finer grain size. The density and average thermal coefficients of the studied glass-ceramics were influenced by the content of F À ions. All the results showed that CaF 2 did promote initial crystallization of LZAS glass and can be used as an effective nucleating agent in the LZAS system. *

Coal fires are serious health and safety hazards throughout the world. In underground, coal spontaneous combustion process often starts with the inside of coal, which makes it difficult to determine the ignition point. For example, the coal fire happened in high caved area of roadway is often hard to be noticed. Once the smoke appears, it has already been late to take control measures. In this paper, Simulation analysis of microcirculation flow field velocity distribution, temperature distribution and the possible distribution of the coal spontaneous combustion zone are preformed which could provide a good scientific and reasonable understanding of the fire risk due to microcirculation in loose coal in underground roadway.

In recent years, shale oil and gas exploitation has attracted much attention, and the problems of borehole shrinkage and casing damage due to creep property of deep shale rock cannot be ignored. Especially, deep shale rock under the condition with containing water behaves shows stronger creep mechanical behavior. The creep mechanical behavior has direct influence on borehole shrinkage and casing load. The potential engineering risks need mechanism explanation and quantitative assessment. The creep mechanical behavior of deep shale rocks was studied by experiments, meanwhile the creep rate of shale with the condition of containing water was measured. The creep parameters were fitted according to the power-law model, and the parameter of A and n in the model can be obtained. On the basis of experiments, a three-dimensional multilayer wellbore model is established to numerically simulate the creep behavior of shale rock and the influence on the casing loading. In the experiment of our study, the shale under the condition of containing water content accelerates elastic and creep deformation about 1.5 times larger than the one under the condition without containing water. Through the numerical calculation, after one week, in deep layer the casing loading can reach about 158.9MPa when shale rock under the condition of containing water and it can reach about 146.3Pa without containing water. After one year, the casing loading can reach about 548.8MPa when shale rock under the condition of containing water and und it can reach about 517.9MPa without containing water. Creep property of shale rock will lead to the increase of casing loading and damage risk obviously, and it should be taken into consideration for the design of casing.