The bending creep and its disturbance effects of red sandstone rock beam and oil shale rock beam were studied by adopting the self-developed gravitation level s
17α-actoxy-19-nor-progesterone was synthesized by a new efficient stereoselective asymmertric pathway from 19-nor-androst-4-en-3,17-dione in 5-steps reactions
The Sangzhi-Shimen synclinorium, which is in the western margin region of the Hunan-Hubei Province and as the southeast part of the middle Yangtze platform, is