1Geodynamic Zoning Study in Daxing Mine FieldZHU Guang-yi, LI Bao-dong, ZHANG Zhong1-32Study on Lowest Wind Speed and Pressure Loss of Drilling Dust Extraction with Wind-force for BoreholeWANG Hai-feng, LI Zeng-hua, YANG Yong-liang, QI Feng4-63Practice of Methane Drainage in Gob in Chengzhuang Coal MineLI Guo-biao, ZHANG Hai-jun, HE Guang-hui7-94Boring Technology of Long Borehole down Coal SeamHE Ming-chuan9-125Practice of Extinguishing Spontaneous Fire Using Filling Water Way through Short BoreholePENG Xiang-kui13-166Practice of Fighting Fire Technology in Fully-mechanized Caving Roof Faces without Coal ColumnGONG Chun-sheng16-187Development and Application of Automatic Pressure Regulating Device in West Flank of Tangshan Coal MineZHANG Rui-jiang, ZHENG Qing-xue, FENG Hai-feng19-208Application of Liquid CO2 in Mining Fighting Fire21-239Analysis for Breakage Tunnel Destroy in Jinbaotun Coal MineZHOU Yang, KONG Xiang-yi, LI Peng24-2510Improvement of Electric Controlling Return Circuit of Oil Pump of MRH-S100-42 Tunnel Development MachineLI Yun26,3511Additional Time-delay Output Controlling Function of Explosion-proof Type Vacuum Magnetic StarterMA Zhong-kuang27-28,3812Problems Existing in Methane Drainage in Coal Mines of China and Probing into the CountermeasuresWANG Zhao-feng, LIU Jun29-32,4413Analysis for Appearing Characteristic of Gas Dynamic Force Disaster in Gas Abnormal District of Xiandewang Coal MineLI Cheng-wu, MI Wen-bao33-3514Regular Analysis for Coal and Gas Outburst in Sangshuping Coal MineWANG Dong-feng, FENG Yao-ting36-3815Probing into Times of Coal Cutting Revealing when Sampling in Porthole to Determine Methane ContentsWANG Yao-feng39-4016Problems of Environment and Disaster Geodynamic in Coal Mines of LiaoningZHANG Xian-liang, HUANG Qi-wen41-4217Probing into Dip Mining Technology to Mining Raise Coal Column in Lingbei Coal Mine43-4418Probing into Tests of Direct-current Voltage and Leakage Electric Current of Mine Power CableLU Zhou45-4619Analysis for Current Situation of Heavy -duty Lift Winch Moving Down at Full Speed with GravityGUO Min47-4820How to Comprehend Coal Mines Safety Quality StandardizationWANG Run-ping, Li Jiang49-51 