Proposed GSSP for the base of Cambrian Stage 9, coinciding with the first appearance of Agnostotes orientalis, at Duibian, Zhejiang, China

Exposed in natural outcrops near the Duibian Village, Jiangshan County, Zhejiang Province, China, the Duibian B section is proposed as the boundary stratotype for the base of an unnamed stage termed provisionally Cambrian Stage 9. The proposed position of the GSSP is 108.12 m above the base of the Huayansi Formation, at a horizon coinciding with the first appearance of the cosmopolitan agnostoid trilobite Agnostotes orientalis. This horizon coincides also with the first appearance of the cosmopoli-tan polym...     

Desorption-diffusion model and lost gas quantity estimation of coalbed methane from coal core under drilling fluid medium

The differences of coalbed methane(CBM) desorption-diffusion from coal drilling-core under various drilling fluid medium are not considered in the present calculating methods of lost CBM quantity,which leads possibly to the inaccuracy of CBM quantity in coal seam.Here we took the desorption of CBM from coal core under drilling fluid medium as a pressure-swing process,and based on the Langmuir equation and Fick-first law,established the desorption-diffusion model and numerical modeling method of lost gas(inc...     

建立郑州市多用途地籍数据库的思考

本文对郑州市土地利用管理多用途地籍数据库进行了可行性分析,提出建立该数据库的总体设计思路,讨论了建库过程中可能遇到的问题及解决方法。     

含锡自然铜研究

本文对发现于河南毛堂金矿田氧化矿石中的含锡自然铜进行了矿物学研究。该矿物属等轴晶系,O_h~5-F_(m3m),a_0=3.655?,Z=4。化学成分中Cu 90.38(wt)%,Sn 9.38(wt)%,分子式Cu_(18)Sn。含锡自然铜相当于Cu_(18)Sn合金中的a相,在自然界属首次发现。