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pro vyhledávání: '"JIA Mingqu"'
Autor:
JIA Mingqu
Publikováno v:
Gong-kuang zidonghua, Vol 46, Iss 8, Pp 117-122 (2020)
Directional high-level borehole in roof is an important means to control mining pressure-release gas in coal mine underground. Due to limitation of drilling device, the borehole diameter is small in once-through drilling, and borehole group arrangeme
Externí odkaz:
https://doaj.org/article/93bf2c7b27ad4a3992bb11edd0d1b0cd
