摘要：This study develops a multivariate eco-hydrological risk-assessment framework based on the multivari-ate copula method in order to evaluate the occurrence of extreme eco-hydrological events for the Xiangxi River within the Three Gorges Reservoir （TGR） area in China. Parameter uncertainties in marginal distri-butions and dependence structure are quantified by a Markov chain Monte Carlo （MCMC） algorithm. Uncertainties in the joint return periods are evaluated based on the posterior distributions. The proba- bilistic features of bivariate and multivariate hydrological risk are also characterized. The results show that the obtained predictive intervals bracketed the observations well, especially for flood duration. The uncertainty for the joint return period in ＂AND＂ case increases with an increase in the return period for univariate flood variables. Furthermore, a low design discharge and high service time may lead to high bivariate hydrological risk with great uncertainty.

摘要：聚氯乙烯(PVC)是全球产量第三大的聚合物,而乙烯基氯化物是PVC的基本构建单元,催化乙炔氢氯化反应已被广泛应用于乙烯基氯化物的生产。高稳定性无汞催化剂(例如Au基催化剂)的研发对于实现乙炔氢氯化行业的绿色可持续具有重要的工业意义。用p-区(N)杂原子掺杂的贵金属单原子催化剂替代基于汞的催化剂已成为主流做法,在过去的几年中吸引了广泛的研究。N元素的掺杂可以解决催化剂失活和原子利用率低的根本问题,从而形成稳定的超细金属纳米颗粒甚至单原子催化剂,使该催化剂在乙炔氢氯化反应中表现出优异的催化性能。在此基础上,基于最新的理论和实验研究进展,全面回顾N元素调控的乙炔氢氯化催化剂的性质、性能和机制。讨论了催化剂结构与催化活性和稳定性的关系,总结出N掺杂单原子催化剂性能描述符,以强调设计催化剂的关键因素。最后,展望N元素调控催化剂的发展趋势。对性能提升机制和结构-性能关系的深入了解可以为定向合成材料提供参考,从而促进乙炔氢氯化无汞催化剂的实际应用。