近40年湘西州暴雨特征研究

利用1979—2018年湘西州8个县、市国家气象站降水量数据,分析了湘西州暴雨特征。结果表明:湘西州暴雨多发生在汛期5—9月,占全年88%,东部和东南部多,西部和西南部少。夏季暴雨占66%,空间分布北部(龙山)较多,其他县、市东多西少;春季暴雨占全年暴雨的20%,空间分布南多北少;秋季暴雨占14%,西南部较少,中部较多。夏季暴雨强度最大,主要集中在50~164.7 mm/d,春季和秋季暴雨强度相当,主要集中在50~115.7 mm/d和50~116.1 mm/d之间。湘西州暴雨频次的年际变化具有11~19 a和6~10 a两个较明显周期。

Full-scale model tests and nonlinear analysis of prestressed concrete simply supported box girders

Full-scale model tests were carried out on a 30 m span prestressed concrete box girder and a 20 m span prestressed concrete hollow slab. Failure models were prestressed reinforcement tensile failure and crashing of roof concrete, respectively. The ductility indexes of the box girder and hollow slab were 1.99 and 1.23, respectively, according to the energy viewpoint. Based on the horizontal section hypothesis, the nonlinear computation procedure was established using the limited banding law, and it could carry out the entire performance analysis including the unloading, mainly focusing on the ways to achieve the unloading curves computation through stress-strain, moment-curvature and load-displacement curves. Through the procedure, parameters that influence on the bearing capacity, deformation performance and ductility of the structures were analyzed. Those parameters were quantity of prestressed reinforcement and tension coefficients of prestressed reinforcement. From the analysis, some useful conclusions can be obtained.

2015—2020年口服轮状病毒活疫苗的趋势分析和质量评价

目的统计分析我国2015—2020年口服轮状病毒活疫苗质量属性检测数据,评价其质量可控性和工艺稳定性。方法根据口服轮状病毒活疫苗注册标准和中国药典(2010、2015、2020年版)规定的方法对634批口服轮状病毒活疫苗的病毒滴度、热稳定性、抗生素残留量、渗透压以及pH进行检测,应用Minitab和GraphPad数据软件对检测结果进行单值移动极差控制图分析、方差分析和箱线图分析。结果2015—2020年634批口服轮状病毒活疫苗的病毒滴度均在每毫升5.5~7.0 lg半数细胞培养物感染量(50%cell culture infectious does,CCID_(50)),热稳定性试验病毒滴度均不低于5.5 lgCCID_(50)/ml、滴度下降不大于1.0 lg CCID_(50)/ml、抗生素残留量、渗透压以及pH均在国家标准范围及企业内控标准范围内。结论2015—2020年的口服轮状病毒活疫苗产品有较好的质量可控性,生产工艺稳定。