1Experimental Study on Influence of Dry-wet Circulation on Coal Firmness CoefficientYANG Zhiwei, MA Yankun, YANG Shuangwen, ZHANG Meng, NIE XianzhongTest·Research1-3,72Critical Value Determination of Sensitivity Index for Forecasting Coal and Gas Outburst in Pingqing MineQIN MuguangTest·Research4-73Study on Optimum Ratio of Cement Grouting in Coal Seam Gas Pressure MeasurementJIANG Chenglin, HU Yinpeng, ZHANG Pan, WANG ChaojieTest·Research8-114Research on Outburst Elimination and Pre-drainage Evaluation for Bedding Holes in Mining FaceZHANG Cheng, CHEN JinshengTest·Research12-14,185Multidimensional Mixed Simulation Study on Smoke Propagation Features of Mine FireZHANG Yutao, CHEN Xiaokun, ZHANG Xichen, LI Yaqing, Jerry TienTest·Research15-186Influence of Firmness Coefficient on Gas Permeability of Different Types of Structure CoalLI Hongtao, ZHANG RuilinTest·Research19-21,257Heat and Humidity Sources Distribution and Variation of Mining Face Based on Surfer8.0DONG HuaijunTest·Research22-258Study on Coal and Rock Impact Damage Characteristics Based on Interface ModelGAO Zhenqiu, LIANG Zhengzhao, LI Congcong, WU XiankaiTest·Research26-299Research on Rock-burst Prevention and Control Under the Influence of Hard Roof Fracture Near GobDING Yingjie, QU Ying, MAI QiaoliTest·Research30-3210Distribution Law of Advanced Abutment Pressure of Gangue Backfilling Working FaceSUN Shaolong, ZHANG JinwangTest·Research33-3511Research on Top Coal Caving Property at Working Face End of Stagger Arrangement Roadway LayoutWANG Huiyue, FAN Zhigang, HUANG ZhengyanTest·Research36-38,4212Optimization Analysis on Supporting Angle of Large Dip Angle Jointed Roadway Based on Block TheoryWANG Jianchang, WANG Tongxu, MA Depeng, ZHANG XuepengTest·Research39-4213Pre-grouting Reinforcement for High Gassy Isolated Working Face in Two Ending RoadwaysLI WenzhouTest·Research43-4614Research on Characters of Interface Between Coal and Rock in Horizontal Section Fully Mechanized Caving Mining of Steep Coal Seam by Two-round Interval Caving TechniqueSONG Zhengyang, ZHANG JinwangTest·Research47-49,5315Research on Reasonable Width of Coal Pillar at Fully Mechanized Working Face with Large Mining HeightLOU JinfuTest·Research50-5316Optimazation of Construction Technology for Downward Gas Extration BoreholesWEN Kunpeng, SHI Biming, ZHOU ZhankuiTechnology·Innovation54-5717Backfill Mining with Super-high Water Bag and Gob-side Entry Retaining Technology for a MineCHEN Liang, CHEN Shangyuan, DU BinbinTechnology·Innovation58-6018Rapid Coal Uncovering Technology in Small Angle and High Outburst Coal SeamSU Weiwei, LI Jianbing, CHEN XiangjunTechnology·Innovation61-6419Automatic Fire Preventing and Extinguishing Technology for Underground Area Based on Multi-sensorMA LongTechnology·Innovation65-6720Fire Extinguishing Technology for High Gas Coal Mine with Oil-bearing SandstoneYUAN Chongliang, XU Chenglin, WANG JundeTechnology·Innovation68-70 