China has widely distributed silver deposits,and is rich in silver resources.Although silver deposits are mainly associated with Pb-Zn deposits,a number of independent silver deposits have also been discovered in recent years.Silver deposits include different types,such as submarine volcanism and continental volcanism related type,intrusion related type,and sedimentary related type.This study summarized the metallogenic regularity of China’s silver deposits systematically based mainly on the data from 490 silver deposits.It is shown that submarine volcanic sedimentary type,continental volcanic or sub-volcanic type,skarn type,hydrothermal type(including vein type and stratabound type),sedimentary metamorphic type,sedimentary type and regolith type should be regarded as the most important prediction types of silver deposit.A total of 32 silver mineralization belts and 111 silver concentration areas have been delineated.The map of "Spatial distribution of silver mineralization belts in China" and other series of maps finished in this study may provide a theoretical basis for the evaluation and prognosis of silver resources potential in China. 相似文献
It is known that a lot of uncertainties are involved in geotechnical design of energy piles. In this paper, a Bayesian updating framework is presented to characterize those uncertainties. The load-transfer model is developed to predict the thermomechanical response of energy piles. Considering the cross-case variability of the uncertainty in the axial strains of pile, the global model bias is firstly calibrated by establishing a comprehensive database consisting of 12 energy pile cases. Furthermore, the uncertainty in input parameters is considered in the Bayesian updating of model bias in a specific case. The variability of the uncertain parameters is effectively reduced after updating. The coefficient of variation of prediction is decreased from 0.34 to 0.13. The present framework can well quantify uncertain factors and improve the accuracy and reliability of the prediction model.
Natural Resources Research - Mining-induced fracture plays a key role in gas drainage for gas burst-prone underground coal mines, especially for closely multilayered coal seams. The layout and... 相似文献