TY - Data T1 - Patents on design and development of key equipment and tools for polar drilling A1 - chi shenggao DO - 10.12072/ncdc.SRIPE.db1695.2022 PY - 2022 DA - 2022-02-25 PB - National Cryosphere Desert Data Center AB - Five patents were applied in Wuhan, Hubei Province from 2017 to 2020, including screw drill anti dropping technology, PDC bit, diamond composite, rubber formula, etc. DB - NCDC UR - http://www.ncdc.ac.cn/portal/metadata/3946a3c1-059e-40d8-88f0-70ab8543084f ER -