2) coal mine of North China type
华北型煤田矿井
3) mine area of north China
华北煤矿区
4) North China type coal field
华北型煤田
1.
According to the electric features of North China type coal field,the principle analysis and exploration cases of the electric magnetic probing showed that a largest pole distance,longer observation time and lower frequency would be needed to reach the expected probing depth.
针对华北型煤田地层电性特点,通过电磁探测原理分析与勘察实例,说明了在此类地区需要更大的极距、更长的观测时间和更低的频率才能达到预期的探测深度。
5) coalfield in northern China
华北煤田
补充资料：华北野战军(见华北军区)
华北野战军(见华北军区)
North China Field Army
Huabei Yezhanlun华北野战军(North ehina Field Army)见华北军区。
说明：补充资料仅用于学习参考，请勿用于其它任何用途。
参考词条