pit prop

常见例句

A fork waveguide model is proposed and the mode matching and multi-mode network technique are used to analyze the transmission characteristics of rectangular tunnel with metallic pit prop.
针对矩形巷道中由于金属支护立柱的存在而带来的分叉不连续问题,提出用分叉波导模型并用模式匹配法和多模传输理论分析传输特性。
a pit prop(= one used in a coal mine)
煤矿坑木
The conservation of pit prop at ancient copper mine
古铜矿遗址地表坑木的保护
The timber is used for construction, poles, vehicles, pit props, railway sleepers, and wood fiber.
木材用于建设，杆，车辆，具洼点的支柱，铁路睡眠者和木头纤维。
Effect of Metallic Pit Prop on Transmission Characteristics in Tunnel
金属支护立柱对巷道无线传输特性的影响
The children were playing in the sand pit.
孩子们在沙坑中玩耍。