For mining extra-steep-thick coal seam, the sublevel top coal caving is a high efficient method in practical engineering. However, major challenges associated with mining high-section top-coal-caving （HSTCC） are rel...For mining extra-steep-thick coal seam, the sublevel top coal caving is a high efficient method in practical engineering. However, major challenges associated with mining high-section top-coal-caving （HSTCC） are related to the resulting high ground stresses. Inevitability, using the high-section sublevel top coal caving for extra-steep-thick coal seam, the large scale of mined-out area appears. If the prefracture blasting and hydraulic fracture techniques are utilized, the top coal damage and cracks will develop, and the mining complexity will increase, such as seam inclination, continuity, mechanical characteristics of roof and susceptibility of top coal, etc. First, the field conditions of B1＋2 seam were investigated at the ＋588 level of the Weihuliang Underground Mine of China. Subsequently, according to caving mechanism of strata response obtained from several special models including physical simulation tests and numerical simulation models, the prefracture process including blasting and injecting water were analyzed. Then, the prefracture blasting technique was successfully applied to the caving of 52 m-sublevel seam. Finally, the effects were verified by advanced detecting instruments, and the results show these methods and measurements are feasible and valid.展开更多
The purpose of this study was to assess the suppressive effect of Waste Vegetable Biomasses （WVBs） treated by the Steam Explosion technique in a continuous plant, against soil-borne plant pathogens. In order to asse...The purpose of this study was to assess the suppressive effect of Waste Vegetable Biomasses （WVBs） treated by the Steam Explosion technique in a continuous plant, against soil-borne plant pathogens. In order to assess their disease suppression, five WVBs （Miscanthus biomass, durum wheat straw, rice straw, corn stalk and wood shaving） and commercial compost were tested in vivo at three different doses （10, 20 and 30% of potting mix） on seven horticultural pathosystems plant/fungus： tomato/Phytophthora nicotianae, cucumber/Pythium ultimum, lettuce/Fusariurn oxysporum f. sp. lactucae, melordFusariurn oxysporum f. sp. melonis, bearffRhizoctonia solani, eggplant/Verticillium dahlie and fennel/Sclerotinia sclerotiorum. The results showed that the corn stalk was more efficient respect to Miscanthus, compost, wheat straw, rice straw and wood shaving in all the patbosystems and at all the doses tested. The corn stalk suppression ranged from 97% in eggplant/F, dahliae to 35% in lettuce/F, oxysporum f. sp. lactucae, and it was significantly higher with respect to the other substrates. In general, the wheat straw, rice straw and wood shaving were statistically found less efficient as suppressive substrate with respect to corn stalk, Miscanthus and compost at the 30% dose in four pathosystems In particular, the wood shaving suppressiveness ranged from 48% in eggplant/V, dahliae to 12% in lettuce/F, oxysporum f. sp. lactucae. The different suppressiveness observed could be attributed to different concentration of the microbial inhibitory substances （furfurals, organic acids and lignosulfonates） produced during the processing of fresh biomass.展开更多
基金Supported by the Natural Science Foundation of China （50375026, 50375028）
文摘For mining extra-steep-thick coal seam, the sublevel top coal caving is a high efficient method in practical engineering. However, major challenges associated with mining high-section top-coal-caving （HSTCC） are related to the resulting high ground stresses. Inevitability, using the high-section sublevel top coal caving for extra-steep-thick coal seam, the large scale of mined-out area appears. If the prefracture blasting and hydraulic fracture techniques are utilized, the top coal damage and cracks will develop, and the mining complexity will increase, such as seam inclination, continuity, mechanical characteristics of roof and susceptibility of top coal, etc. First, the field conditions of B1＋2 seam were investigated at the ＋588 level of the Weihuliang Underground Mine of China. Subsequently, according to caving mechanism of strata response obtained from several special models including physical simulation tests and numerical simulation models, the prefracture process including blasting and injecting water were analyzed. Then, the prefracture blasting technique was successfully applied to the caving of 52 m-sublevel seam. Finally, the effects were verified by advanced detecting instruments, and the results show these methods and measurements are feasible and valid.
文摘The purpose of this study was to assess the suppressive effect of Waste Vegetable Biomasses （WVBs） treated by the Steam Explosion technique in a continuous plant, against soil-borne plant pathogens. In order to assess their disease suppression, five WVBs （Miscanthus biomass, durum wheat straw, rice straw, corn stalk and wood shaving） and commercial compost were tested in vivo at three different doses （10, 20 and 30% of potting mix） on seven horticultural pathosystems plant/fungus： tomato/Phytophthora nicotianae, cucumber/Pythium ultimum, lettuce/Fusariurn oxysporum f. sp. lactucae, melordFusariurn oxysporum f. sp. melonis, bearffRhizoctonia solani, eggplant/Verticillium dahlie and fennel/Sclerotinia sclerotiorum. The results showed that the corn stalk was more efficient respect to Miscanthus, compost, wheat straw, rice straw and wood shaving in all the patbosystems and at all the doses tested. The corn stalk suppression ranged from 97% in eggplant/F, dahliae to 35% in lettuce/F, oxysporum f. sp. lactucae, and it was significantly higher with respect to the other substrates. In general, the wheat straw, rice straw and wood shaving were statistically found less efficient as suppressive substrate with respect to corn stalk, Miscanthus and compost at the 30% dose in four pathosystems In particular, the wood shaving suppressiveness ranged from 48% in eggplant/V, dahliae to 12% in lettuce/F, oxysporum f. sp. lactucae. The different suppressiveness observed could be attributed to different concentration of the microbial inhibitory substances （furfurals, organic acids and lignosulfonates） produced during the processing of fresh biomass.
