Three M_(W)>7.0 earthquakes in 2020-2021 occurred in the Shumagin seismic gap and its adjacent area of the Alaska-Aleutian subduction zone,including the Mw7.8 Simeonof thrust earthquake on July 22,2020,the M_(W)7.6...Three M_(W)>7.0 earthquakes in 2020-2021 occurred in the Shumagin seismic gap and its adjacent area of the Alaska-Aleutian subduction zone,including the Mw7.8 Simeonof thrust earthquake on July 22,2020,the M_(W)7.6 Sand Point strike-slip earthquake on October 19,2020,and the M_(W)8.2 Chignik thrust earthquake on July 29,2021.The spatial and temporal proximity of these three earthquakes prompts us to probe stress-triggering effects among them.Here we examine the coseismic Coulomb stress change imparted by the three earthquakes and their influence on the subduction interface.Our results show that:(1)The Simeonof earthquake has strong loading effects on the subsequent Sand Point and Chignik earthquakes,with the Coulomb stress changes of 3.95 bars and 2.89 bars,respectively.The Coulomb stress change caused by the Sand Point earthquake at the hypocenter of the Chignik earthquake is merely around 0.01 bars,suggesting the negligible triggering effect on the latter earthquake;(2)The triggering effects of the Simeonof,Sand Point,and Chignik earthquakes on aftershocks within three months are not well pronounced because of the triggering rates of 38%,14%,and 43%respectively.Other factors may have played an important role in promoting the occurrence of these aftershocks,such as the roughness of the subduction interface,the complicated velocity structure of the lithosphere,and the heterogeneous prestress therein;(3)The three earthquakes caused remarkable coseismic Coulomb stress changes at the subduction interface nearby these mainshocks,with an average Coulomb stress change of 3.2 bars in the shallow region directly inwards the trench.展开更多
详细梳理了新版国际标准ISO 80601-2-84:2020 Medical electrical equipment—Part 2-84:Particular requi-rements for basic safety and essential performance of ventilators for the emergency medical services environment,比较...详细梳理了新版国际标准ISO 80601-2-84:2020 Medical electrical equipment—Part 2-84:Particular requi-rements for basic safety and essential performance of ventilators for the emergency medical services environment,比较了ISO 80601-2-84:2020与ISO 10651-3:1997 Lung ventilators for medical use—Part 3:Particular requirements for emergency and transport ventilators的差异,分析了新版国际标准对工作数据准确性、危险输出的防护、呼吸机系统、使用环境等几方面的要求,可为生产企业和检验技术人员正确理解标准条款的要求和内涵提供参考。展开更多
T/CMA CC 045-2020《计量电子原始记录通用规范》实施以来,其在规范计量电子原始记录、提高工作效率、提高质量控制水平、提高证书的可靠性等方面都有着积极的作用。但是该标准也存在一定的短板,未能统一标准的文件格式,对于电子记录防...T/CMA CC 045-2020《计量电子原始记录通用规范》实施以来,其在规范计量电子原始记录、提高工作效率、提高质量控制水平、提高证书的可靠性等方面都有着积极的作用。但是该标准也存在一定的短板,未能统一标准的文件格式,对于电子记录防伪加密要求偏低,对于不确定度的覆盖不全面,对新技术的支持略有不足,这些需要在今后的实践中加以修正,以便更好地服务于计量行业的发展。展开更多
基金supported by grants from the National Natural Science Foundation of China(Grant No.sU2139205,41774011,41874011)the National Key Research and Development Program of China(Grant No.2018YFC1503605)。
文摘Three M_(W)>7.0 earthquakes in 2020-2021 occurred in the Shumagin seismic gap and its adjacent area of the Alaska-Aleutian subduction zone,including the Mw7.8 Simeonof thrust earthquake on July 22,2020,the M_(W)7.6 Sand Point strike-slip earthquake on October 19,2020,and the M_(W)8.2 Chignik thrust earthquake on July 29,2021.The spatial and temporal proximity of these three earthquakes prompts us to probe stress-triggering effects among them.Here we examine the coseismic Coulomb stress change imparted by the three earthquakes and their influence on the subduction interface.Our results show that:(1)The Simeonof earthquake has strong loading effects on the subsequent Sand Point and Chignik earthquakes,with the Coulomb stress changes of 3.95 bars and 2.89 bars,respectively.The Coulomb stress change caused by the Sand Point earthquake at the hypocenter of the Chignik earthquake is merely around 0.01 bars,suggesting the negligible triggering effect on the latter earthquake;(2)The triggering effects of the Simeonof,Sand Point,and Chignik earthquakes on aftershocks within three months are not well pronounced because of the triggering rates of 38%,14%,and 43%respectively.Other factors may have played an important role in promoting the occurrence of these aftershocks,such as the roughness of the subduction interface,the complicated velocity structure of the lithosphere,and the heterogeneous prestress therein;(3)The three earthquakes caused remarkable coseismic Coulomb stress changes at the subduction interface nearby these mainshocks,with an average Coulomb stress change of 3.2 bars in the shallow region directly inwards the trench.
文摘详细梳理了新版国际标准ISO 80601-2-84:2020 Medical electrical equipment—Part 2-84:Particular requi-rements for basic safety and essential performance of ventilators for the emergency medical services environment,比较了ISO 80601-2-84:2020与ISO 10651-3:1997 Lung ventilators for medical use—Part 3:Particular requirements for emergency and transport ventilators的差异,分析了新版国际标准对工作数据准确性、危险输出的防护、呼吸机系统、使用环境等几方面的要求,可为生产企业和检验技术人员正确理解标准条款的要求和内涵提供参考。
文摘T/CMA CC 045-2020《计量电子原始记录通用规范》实施以来,其在规范计量电子原始记录、提高工作效率、提高质量控制水平、提高证书的可靠性等方面都有着积极的作用。但是该标准也存在一定的短板,未能统一标准的文件格式,对于电子记录防伪加密要求偏低,对于不确定度的覆盖不全面,对新技术的支持略有不足,这些需要在今后的实践中加以修正,以便更好地服务于计量行业的发展。
