The epicenter of the Luxian M_(S)6.0 earthquake on September 16,2021,was located in the southern Sichuan Basin,which is a historically seismically quiescent area.In recent years,the frequency of earthquakes has increa...The epicenter of the Luxian M_(S)6.0 earthquake on September 16,2021,was located in the southern Sichuan Basin,which is a historically seismically quiescent area.In recent years,the frequency of earthquakes has increased with the large-scale exploitation of shale gas.No evident surface fractures or seismic faults were observed after the Luxian earthquake.Based on high-quality data recorded by a dense seismic array composed of 70 portable stations with an average spacing of 2-3 km,a highresolution seismic catalog was constructed for 7 days before and 36 days after the M_(S)6.0 earthquake using LOC-FLOW,an effective workflow of phase picking,phase association,and earthquake location.Based on the new earthquake catalog,four earthquake clusters that occurred within the Yujiasi Syncline during this period were identified.Among them,the M_(S)6.0 main earthquake sequence had a NW-SE trend and inclined towards the SW,with a length of approximately 8 km and width of 5 km.The M_(S)6.0 earthquake sequence only appeared after the mainshock.The other three clusters were located in the northeast direction of the M_(S)6.0 earthquake sequence,all of which were NE-SW trending strips and had no evident direct correlation with the M_(S)6.0 mainshock.The focal depth was concentrated in the range of 2-7 km.Based on the seismic sequence profile and structural background,the M_(S)6.0 seismic structure may be a blind buried fault zone with a NW strike composed of multiple small conjugate faults with NE and SW dip.The fault was not exposed on the surface and was related to the detachment structure in the deep part of the Sichuan Basin.展开更多
柞蚕(Antheraea pernyi)幼虫体色是新品种选育的重要标记性状,为了研究柞蚕幼虫体色的变化规律,利用Image-Pro Plus 6.0软件对2个黄蚕血统柞蚕品种、3个青黄蚕血统柞蚕品种幼虫的体色进行了分析。试验采用RGB颜色分析模式,分析了红(R)、...柞蚕(Antheraea pernyi)幼虫体色是新品种选育的重要标记性状,为了研究柞蚕幼虫体色的变化规律,利用Image-Pro Plus 6.0软件对2个黄蚕血统柞蚕品种、3个青黄蚕血统柞蚕品种幼虫的体色进行了分析。试验采用RGB颜色分析模式,分析了红(R)、绿(G)、蓝(B)、RGB总和、RGB平均值和明度(L)等6项数据。试验结果表明,三原色中的R、G、B均与柞蚕幼虫不同龄期间差异相关,同一血统不同品种间体色差异不显著,青黄蚕血统、黄蚕血统的柞蚕2~4龄各龄期之间体色差异显著,进入4龄期后体色趋于稳定,因此品种选育工作可在4龄期进行体色选择。展开更多
基金supported by Fundamental Research Funds from the Institute of Geophysics,China Earthquake Administration(Nos.DQJB22B26 and DQJB22B19)the National Key Research and Development Program of China(No.2020YFA0710603-02).
文摘The epicenter of the Luxian M_(S)6.0 earthquake on September 16,2021,was located in the southern Sichuan Basin,which is a historically seismically quiescent area.In recent years,the frequency of earthquakes has increased with the large-scale exploitation of shale gas.No evident surface fractures or seismic faults were observed after the Luxian earthquake.Based on high-quality data recorded by a dense seismic array composed of 70 portable stations with an average spacing of 2-3 km,a highresolution seismic catalog was constructed for 7 days before and 36 days after the M_(S)6.0 earthquake using LOC-FLOW,an effective workflow of phase picking,phase association,and earthquake location.Based on the new earthquake catalog,four earthquake clusters that occurred within the Yujiasi Syncline during this period were identified.Among them,the M_(S)6.0 main earthquake sequence had a NW-SE trend and inclined towards the SW,with a length of approximately 8 km and width of 5 km.The M_(S)6.0 earthquake sequence only appeared after the mainshock.The other three clusters were located in the northeast direction of the M_(S)6.0 earthquake sequence,all of which were NE-SW trending strips and had no evident direct correlation with the M_(S)6.0 mainshock.The focal depth was concentrated in the range of 2-7 km.Based on the seismic sequence profile and structural background,the M_(S)6.0 seismic structure may be a blind buried fault zone with a NW strike composed of multiple small conjugate faults with NE and SW dip.The fault was not exposed on the surface and was related to the detachment structure in the deep part of the Sichuan Basin.
文摘柞蚕(Antheraea pernyi)幼虫体色是新品种选育的重要标记性状,为了研究柞蚕幼虫体色的变化规律,利用Image-Pro Plus 6.0软件对2个黄蚕血统柞蚕品种、3个青黄蚕血统柞蚕品种幼虫的体色进行了分析。试验采用RGB颜色分析模式,分析了红(R)、绿(G)、蓝(B)、RGB总和、RGB平均值和明度(L)等6项数据。试验结果表明,三原色中的R、G、B均与柞蚕幼虫不同龄期间差异相关,同一血统不同品种间体色差异不显著,青黄蚕血统、黄蚕血统的柞蚕2~4龄各龄期之间体色差异显著,进入4龄期后体色趋于稳定,因此品种选育工作可在4龄期进行体色选择。
