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To study the effect of coal pressure on gas extraction under fluid‐solid coupling, the effect of gas extraction radius under different pore sizes and treatment methods was simulated by using COMSOL Multiphysics software, the time evolution law of gas pressure on coal surface was obtained, and the numerical simulation results were verified by the observation of flow rate and concentration in experimental mine combined with fluid‐solid interaction. The results show that the distance of extraction radius increases with the increase of borehole diameter, and the relation between extraction time and extraction radius is a power function, but the increase gets smaller and smaller until it becomes zero. For Φ98 mm borehole and Φ120 mm borehole, hydraulic treatment can increase the efficiency of gas extraction by 31.3% and 22.7%, respectively. For hydraulic treatment and conventional treatment, the ratio of gas drainage effect by enlarging hole size is 6.3% and 13.8% respectively. Compared with the areas without gas extraction under the four conditions, the descending speed of gas pressure from fast to slow is Φ120 mm hydraulic flushing treatment, Φ98 mm hydraulic flushing treatment, Φ120 mm conventional treatment, Φ98 mm conventional treatment. Compared with four different conditions, after 180 days of extraction the coal gas pressure decreased by 75.3% within reasonable hole spacing. At the same time, in multi‐hole pumping, the influence area of adjacent borehole is larger than that of single‐hole pumping, and the spacing of borehole should be less than twice the radius of pumping. [ABSTRACT FROM AUTHOR]

Recent studies showed that Guaiazulene (GA) and Sodium guaiazulene sulfonate (GAS-Na) have good anti-gastric ulcer effect. Here, two series of GA derivatives were synthesized and evaluated for their anti-gastric ulcer activity. The data obtained from in vivo testing of these compounds in a rodent ethanol-induced stomach injury model are discussed. Among the tested compounds, A1, A4, and A9 (ulcer index: 1.125 ± 1.246**, 1.714 ± 0.756*, 1.875 ± 1.126*) exhibited better anti-gastric ulcer activity than the positive control Omeprazole (2.005 ± 1.011*). The information got from these studies and the results of 3D-SAR investigation may be useful in the design of novel anti-gastric ulcer agents. [ABSTRACT FROM AUTHOR]