This experiment bases on different permeability in different directions of coal seam cleats. To arrange methane drainage direction the directions vertical and parallel to face cleat are adopted.
根据煤层割理渗透率的各向异性，采用垂直面割理和平行面割理两个方向布置钻孔抽放煤层气。
Drainage was to the north and individual channels bifurcate in that direction.
整个水系向北排水，各个河道朝该方向分叉。
Purpose: To study the clinical value of bi-direction drainage by PTCD in the therapy of malignant obstructive jaundice.
目的：探讨通过PT CD内外引流对恶性阻塞性黄疸的治疗价值以及操作方法的改进。
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