分析了其中4种孔底换钻头钻具的结构及工作原理；
The esigns and working principles of 4 types of it are analysed.
现场的应用实践证明，孔底起爆技术可以获得良好的经济技术效果。
The practical application has proven that hole-bottom initiating technique can achieve better technical results and economic benefits.
为此而开发了新型矿用智能钻孔测温仪器，用于孔底温度信息的采集。
So this thermometric indicator instrument has been developed for the collection of the hole temperature information.
应用推荐