Upper bound analysis of slope stability with nonlinear failure criterion based on strength reduction technique

Based on the upper bound limit analysis theorem and the shear strength reduction technique, the equation for expressing critical limit-equilibrium state was employed to define the safety factor of a given slope and its corresponding critical failure mechanism by means of the kinematical approach of limit analysis theory. The nonlinear shear strength parameters were treated as variable parameters and a kinematically admissible failure mechanism was considered for calculation schemes. The iterative optimization method was adopted to obtain the safety factors. Case study and comparative analysis show that solutions presented here agree with available predictions when nonlinear criterion reduces to linear criterion, and the validity of present method could be illuminated. From the numerical results, it can also be seen that nonlinear parameter m, slope foot gradient β, height of slope H, slope top gradient α and soil bulk density γ have significant effects on the safety factor of the slope.     

二氧化碳矿化磷石膏制硫酸铵和碳酸钙技术

针对目前CO2减排和工业固废磷石膏处理的问题,中石化与四川大学合作开展了利用磷石膏直接矿化尾气中低浓度CO2联产硫基复肥与碳酸钙的CCU技术路线研究,并逐步推进该技术产业化。该项目以废制废,把捕集与利用两个环节合二为一,节省捕集成本,具有显著的环境效益和社会效益。     

多导丝斑块挤压结合双腔微导管在复杂慢性冠状动脉闭塞病变介入治疗中的应用

【摘要】 目的 观察冠状动脉慢性完全闭塞（CTO）经皮冠状动脉介入治疗（PCI）术中球囊难以通过靶病变时应用双腔微导管辅助多导丝斑块挤压技术开通的有效性和安全性。方法 回顾性分析2016年9月至2018年4月在解放军第九八〇医院成功接受PCI治疗的280例冠状动脉CTO患者临床资料。根据导丝通过病变闭塞段后最小球囊是否能通过分成两组,球囊通过困难并接受双腔微导管辅助多导丝斑块挤压技术患者为实验组（n=60）例,导丝和球囊顺利通过闭塞段患者为对照组（n=220）。观察两组冠状动脉病变及PCI治疗情况,比较住院期和出院后6个月主要心血管不良事件（MACE）发生率。结果 倾向性评分匹配前,实验组严重钙化发生率、钝形残端或无残端发生率均显著高于对照组（11.7%比4.55%,P=0.041;80.0%比59.1%,P=0.003）,差异均有统计学意义。日本多中心慢性完全闭塞注册研究（J-CTO）评分≥2分、≥3分患者比率均显著高于对照组（85%比64.1%,P=0.002;43.3%比26.8%,P=0.014）,差异均有统计学意义。倾向性匹配前技术成功率实验组为93.3%（56/60）,对照组为（94.1%,207/220）,差异无统计学意义（P＞0.05）;操作成功率分别为80.0%（48/60）、92.3%（203/220）,差异有统计学意义（P=0.006）。倾向性评分匹配后,两组技术成功率、操作成功率差异均无统计学意义（均P＞0.05）。结论 PCI术中导丝通过但最小球囊或微导管