A magnitude 5.5 earthquakes occurred in Eryuan County,Dali Bai Autonomous Prefecture,Yunnan Province,China,on March 3.And a magnitude 5.0 earthquake occurred in the same place on April 17,2013,i.e.,45 days later.Then,...A magnitude 5.5 earthquakes occurred in Eryuan County,Dali Bai Autonomous Prefecture,Yunnan Province,China,on March 3.And a magnitude 5.0 earthquake occurred in the same place on April 17,2013,i.e.,45 days later.Then,on May 21,2021,multiple earthquakes,one with magnitude 6.4 and several at 5.0 or above,occurred in Yangbi County,Dali Bai Autonomous Prefecture,Yunnan Province,China.All of these occurred in the Weixi-QiaohouWeishan fault zone.In this study,1,874 seismic events in Yangbi and Eryuan counties were identified by automatic micro-seismic identification technology and the first arrivals were picked up manually.Following this,a total of 11,968 direct P-wave absolute arrivals and 73,987 high-quality Pwave relative arrivals were collected for joint inversion via the double difference tomography method.This was done to obtain the regional three-dimensional fine crustal P-wave velocity structure.The results show that the travel time residuals before and after inversion decreased from the initial–0.1–0.1 s to–0.06–0.06 s.The upper crust in the study area,which exhibited a low-velocity anomaly,corresponded to the basin region;this indicated that the low-velocity anomaly in the shallow part of the study area was affected by the basin.Results also showed some correlation between the distribution of the earthquakes and velocity structure,as there was a lowvelocity body Lv1 with a wide distribution at depths ranging from 15–20 km in the Yangbi and Eryuan earthquake regions.In addition,earthquakes occurred predominantly in the highlow velocity abnormal transition zone.The low-velocity body in the middle and lower crust may be prone to concentrating upper crustal stress,thus leading to the occurrence of earthquakes.展开更多
Background:Schistosomiasis was severely prevalent in Yunnan Province,and it is difficult to achieve its elimination by convention approaches due to complexity of the nature.We explored the comprehensive model to elimi...Background:Schistosomiasis was severely prevalent in Yunnan Province,and it is difficult to achieve its elimination by convention approaches due to complexity of the nature.We explored the comprehensive model to eliminate schistosomiasis in Eryuan County,Yunnan Province,the People’s Republic of China,through integration with the ecological protection programme in Erhai Lake,in order to promote an efficient elimination strategy.We expected that this model is able to be tailored to other local settings,which help achieve the goal of precisely eliminating the disease in Yunnan Province.Methods:Eryuan County of Yunnan Province was chosen as the study area,where the data on environmental protection activities in Erhai Lake and on the schistosomiasis control programme were collected through different departments of Erhai County government since 2015.System modelling was performed using system dynamics software to establish a simulation model in order to evaluate the effectiveness of intervention activities.Results:Ecological approaches to control schistosomiasis in Eryuan County consist of three major components:(i)implementing precise interventions to stop schistosomiasis transmission by means of controlling the source of infection,blocking the biological transmission chains and cutting off the route of disease transmission;(ii)employing ecological approaches to improve the co-effectiveness of environmental protection and schistosomiasis prevention in the study area;and(iii)strengthening the professional skills of personnel involving in the schistosomiasis control programme.Simulation results showed that this strategy could speed up the progress of schistosomiasis control programme moving from the control stage to the elimination stage.Conclusions:Ecological approaches implemented in schistosomiasis endemic areas of the Eryuan region are able to improve the co-effectiveness of environmental protection and schistosomiasis control,providing a new avenue for eliminating schistosomiasis thanks to the application of precise interventions.展开更多
云南洱源县溪灯坪金矿矿体主要赋存于新近系上新统三营组二段第三层(N 2 S 2-3)和第二层(N 2 S 2-2)硅质角砾岩、硅化粉砂岩、含砾砂岩、砾岩及第四系残坡积层堆积物中。呈层状、似层状、透镜状、脉状产出。矿床成因类型为喜山期浅成(富...云南洱源县溪灯坪金矿矿体主要赋存于新近系上新统三营组二段第三层(N 2 S 2-3)和第二层(N 2 S 2-2)硅质角砾岩、硅化粉砂岩、含砾砂岩、砾岩及第四系残坡积层堆积物中。呈层状、似层状、透镜状、脉状产出。矿床成因类型为喜山期浅成(富碱)构造岩浆活动初始成矿-第四纪热泉活动叠加改造形成的蚀变岩型金矿床。展开更多
基金funded by the general project of National Natural Science Foundation of China(No.41774072).
文摘A magnitude 5.5 earthquakes occurred in Eryuan County,Dali Bai Autonomous Prefecture,Yunnan Province,China,on March 3.And a magnitude 5.0 earthquake occurred in the same place on April 17,2013,i.e.,45 days later.Then,on May 21,2021,multiple earthquakes,one with magnitude 6.4 and several at 5.0 or above,occurred in Yangbi County,Dali Bai Autonomous Prefecture,Yunnan Province,China.All of these occurred in the Weixi-QiaohouWeishan fault zone.In this study,1,874 seismic events in Yangbi and Eryuan counties were identified by automatic micro-seismic identification technology and the first arrivals were picked up manually.Following this,a total of 11,968 direct P-wave absolute arrivals and 73,987 high-quality Pwave relative arrivals were collected for joint inversion via the double difference tomography method.This was done to obtain the regional three-dimensional fine crustal P-wave velocity structure.The results show that the travel time residuals before and after inversion decreased from the initial–0.1–0.1 s to–0.06–0.06 s.The upper crust in the study area,which exhibited a low-velocity anomaly,corresponded to the basin region;this indicated that the low-velocity anomaly in the shallow part of the study area was affected by the basin.Results also showed some correlation between the distribution of the earthquakes and velocity structure,as there was a lowvelocity body Lv1 with a wide distribution at depths ranging from 15–20 km in the Yangbi and Eryuan earthquake regions.In addition,earthquakes occurred predominantly in the highlow velocity abnormal transition zone.The low-velocity body in the middle and lower crust may be prone to concentrating upper crustal stress,thus leading to the occurrence of earthquakes.
基金This study was financially supported by the National Key Research and Development Program of China(grant No.2016YFC1202000)by the International Development Research Center(IDRC),Canada(grant No.108100–001).
文摘Background:Schistosomiasis was severely prevalent in Yunnan Province,and it is difficult to achieve its elimination by convention approaches due to complexity of the nature.We explored the comprehensive model to eliminate schistosomiasis in Eryuan County,Yunnan Province,the People’s Republic of China,through integration with the ecological protection programme in Erhai Lake,in order to promote an efficient elimination strategy.We expected that this model is able to be tailored to other local settings,which help achieve the goal of precisely eliminating the disease in Yunnan Province.Methods:Eryuan County of Yunnan Province was chosen as the study area,where the data on environmental protection activities in Erhai Lake and on the schistosomiasis control programme were collected through different departments of Erhai County government since 2015.System modelling was performed using system dynamics software to establish a simulation model in order to evaluate the effectiveness of intervention activities.Results:Ecological approaches to control schistosomiasis in Eryuan County consist of three major components:(i)implementing precise interventions to stop schistosomiasis transmission by means of controlling the source of infection,blocking the biological transmission chains and cutting off the route of disease transmission;(ii)employing ecological approaches to improve the co-effectiveness of environmental protection and schistosomiasis prevention in the study area;and(iii)strengthening the professional skills of personnel involving in the schistosomiasis control programme.Simulation results showed that this strategy could speed up the progress of schistosomiasis control programme moving from the control stage to the elimination stage.Conclusions:Ecological approaches implemented in schistosomiasis endemic areas of the Eryuan region are able to improve the co-effectiveness of environmental protection and schistosomiasis control,providing a new avenue for eliminating schistosomiasis thanks to the application of precise interventions.
文摘云南洱源县溪灯坪金矿矿体主要赋存于新近系上新统三营组二段第三层(N 2 S 2-3)和第二层(N 2 S 2-2)硅质角砾岩、硅化粉砂岩、含砾砂岩、砾岩及第四系残坡积层堆积物中。呈层状、似层状、透镜状、脉状产出。矿床成因类型为喜山期浅成(富碱)构造岩浆活动初始成矿-第四纪热泉活动叠加改造形成的蚀变岩型金矿床。
