To improve the gas extraction efficiency of single seam with high gas and low air permeability,we developed the"fracturing-sealing"integration technology,and carried out the engineering experiment in the3305...To improve the gas extraction efficiency of single seam with high gas and low air permeability,we developed the"fracturing-sealing"integration technology,and carried out the engineering experiment in the3305 Tunliu mine.In the experiment,coal seams can achieve the aim of antireflection effect through the following process:First,project main cracks with the high energy pulse jet.Second,break the coal body by delaying the propellant blasting.Next,destroy the dense structure of the hard coal body,and form loose slit rings around the holes.Finally,seal the boreholes with the"strong-weak-strong"pressurized sealing technology.The results are as follows:The average concentration of gas extraction increases from8.3%to 39.5%.The average discharge of gas extraction increases from 0.02 to 0.10 m^3/min.The tunneling speeds up from 49.5 to 130 m/month.And the permeability of coal seams improves nearly tenfold.Under the same conditions,the technology is much more efficient in depressurization and antireflection than common methods.In other words,it will provide a more effective way for the gas extraction of single seam with high gas and low air permeability.展开更多
目的探讨下颌水平埋伏阻生智齿高速涡轮钻增隙的临床应用效果。方法随机抽样法选取2017年5月至2018年5月本院72例下颌水平埋伏阻生智齿患者(72颗患牙),随机信封法分为研究组(n=36,行高速涡轮钻增隙)与对照组(n=36,行传统拔牙术)。比较...目的探讨下颌水平埋伏阻生智齿高速涡轮钻增隙的临床应用效果。方法随机抽样法选取2017年5月至2018年5月本院72例下颌水平埋伏阻生智齿患者(72颗患牙),随机信封法分为研究组(n=36,行高速涡轮钻增隙)与对照组(n=36,行传统拔牙术)。比较治疗效果。结果①研究组手术时间短于对照组(t=10.790,P=0.000),术后24 h VAS评分低于对照组(t=12.096,P=0.000);②研究组张口受限轻度率高于对照组(χ~2=4.430,P=0.035),重度率低于对照组(χ~2=4.545,P=0.033);③研究组术后不良事件少于对照组(χ~2=4.571,P=0.032)。结论高速涡轮钻增隙在下颌水平埋伏阻生智齿治疗中的应用,具有手术时间短、疼痛程度轻、术后不良事件少等特点,且可促使开口度尽快恢复。展开更多
基金financial support provided by the State Key Basic Research Program of China(No.2011CB201205)the National Natural Science Foundation of China(No.51074161)the National Science and Technology Support Program(No.2012BAK04B07)
文摘To improve the gas extraction efficiency of single seam with high gas and low air permeability,we developed the"fracturing-sealing"integration technology,and carried out the engineering experiment in the3305 Tunliu mine.In the experiment,coal seams can achieve the aim of antireflection effect through the following process:First,project main cracks with the high energy pulse jet.Second,break the coal body by delaying the propellant blasting.Next,destroy the dense structure of the hard coal body,and form loose slit rings around the holes.Finally,seal the boreholes with the"strong-weak-strong"pressurized sealing technology.The results are as follows:The average concentration of gas extraction increases from8.3%to 39.5%.The average discharge of gas extraction increases from 0.02 to 0.10 m^3/min.The tunneling speeds up from 49.5 to 130 m/month.And the permeability of coal seams improves nearly tenfold.Under the same conditions,the technology is much more efficient in depressurization and antireflection than common methods.In other words,it will provide a more effective way for the gas extraction of single seam with high gas and low air permeability.
文摘目的探讨下颌水平埋伏阻生智齿高速涡轮钻增隙的临床应用效果。方法随机抽样法选取2017年5月至2018年5月本院72例下颌水平埋伏阻生智齿患者(72颗患牙),随机信封法分为研究组(n=36,行高速涡轮钻增隙)与对照组(n=36,行传统拔牙术)。比较治疗效果。结果①研究组手术时间短于对照组(t=10.790,P=0.000),术后24 h VAS评分低于对照组(t=12.096,P=0.000);②研究组张口受限轻度率高于对照组(χ~2=4.430,P=0.035),重度率低于对照组(χ~2=4.545,P=0.033);③研究组术后不良事件少于对照组(χ~2=4.571,P=0.032)。结论高速涡轮钻增隙在下颌水平埋伏阻生智齿治疗中的应用,具有手术时间短、疼痛程度轻、术后不良事件少等特点,且可促使开口度尽快恢复。
