Soaring bird migration often relies on suitable terrain and airflow;therefore,route selection is vital for successful migration.While age and experience have been identified as key factor influencing migration route s...Soaring bird migration often relies on suitable terrain and airflow;therefore,route selection is vital for successful migration.While age and experience have been identified as key factor influencing migration route selection among soaring raptors in the African-Eurasian Flyway,how they shape the migration route of soaring raptors in East Asia is still largely unknown.In this study,we investigated potential variations in the routes and timing in autumn migration of juvenile and older soaring birds,using count data of Greater Spotted Eagles(Clanga clanga)from two coastal sites and two inland sites in China.From 2020 to 2023,we recorded a total of 340 individuals,with the highest site averaging over 90 individuals per autumn,making it one of the world’s top single-season counts and thus a globally important site for this species.We found that 82% and 61% records from coastal sites were juveniles,significantly higher than inland sites(15% and 24%).Juveniles at all four sites exhibited markedly earlier median passage time than non-juveniles,with brief overlapping in their main migration periods.Both coastal sites are located on the tip of peninsulas stretching southwest,requiring long overwater flights if crossing the Bohai Bay or Beibu Gulf,which would be energetically demanding and increase mortality risk.Experienced individuals may have learned to avoid such terrain and subsequent detour,while juveniles are more prone to enter these peninsulas due to lack of experience and opportunities for social learning,or following other raptor species that are more capable of powered flight.Our findings highlight the importance of age and experience in migration route selection of large soaring birds.展开更多
据估计,我国的页岩气可采储量高达20万亿～36万亿m3,虽然我国页岩气储量评估处于初级阶段,但仍然可以肯定我国是页岩气资源丰富的国家之一,如果都能开发,按当前的天然气年产量计算,可以开发200多年。目前国内外多家企业聚焦中国,逐鹿页...据估计,我国的页岩气可采储量高达20万亿～36万亿m3,虽然我国页岩气储量评估处于初级阶段,但仍然可以肯定我国是页岩气资源丰富的国家之一,如果都能开发,按当前的天然气年产量计算,可以开发200多年。目前国内外多家企业聚焦中国,逐鹿页岩气,页岩气有望成为我国常规能源替代品,页岩气的勘探开发必将对我国乃至世界能源格局产生重大影响。但是由于页岩气储层致密,渗透率低至纳达西级,若不采取特殊的增产措施难以实现商业开发。美国是目前唯一实现页岩气商业开采的国家,技术和商业模式都相当成熟,中海石油斥资10多亿美元收购了美国页岩气主产区Eagle Ford 33.3%的股份,该地区页岩气地质储量高达6 000亿m3,开发前景广阔。为提升我国页岩气总体水平,笔者率领技术专家深入考察了美国Eagle Ford页岩气项目,增进了对水平钻井与分段压裂等关键技术的了解,同时分析了相应扶持政策,对中国页岩气的勘探开发具有重要的参考价值。展开更多
Eagle产品检测于7月16～18日在上海举办的第二十届中国国际加工，包装及印刷科技展览会上凭借其新产品系列进一步拓展中国市场。其中，Eagle^TM Tall PRO XSDV检测系统首次亮相，这是一款专为硬质容器而设计的检测系统，其检测效果比普...Eagle产品检测于7月16～18日在上海举办的第二十届中国国际加工，包装及印刷科技展览会上凭借其新产品系列进一步拓展中国市场。其中，Eagle^TM Tall PRO XSDV检测系统首次亮相，这是一款专为硬质容器而设计的检测系统，其检测效果比普通X光机高出50％。同时亮相展会的还有Eagle 2014年全新上市的金属检测机系列，专为检测铁、非铁及不锈钢污染物而设计，具有极高的灵敏度和极佳的稳定性。展开更多
基金Counting at GTL funded by the Shenzhen Zhilan FoundationAlashan SEE Ecological Association+1 种基金Beijing Xianfeng FoundationCounting at PXL was funded by the Alashan SEE Chongqing Center
文摘Soaring bird migration often relies on suitable terrain and airflow;therefore,route selection is vital for successful migration.While age and experience have been identified as key factor influencing migration route selection among soaring raptors in the African-Eurasian Flyway,how they shape the migration route of soaring raptors in East Asia is still largely unknown.In this study,we investigated potential variations in the routes and timing in autumn migration of juvenile and older soaring birds,using count data of Greater Spotted Eagles(Clanga clanga)from two coastal sites and two inland sites in China.From 2020 to 2023,we recorded a total of 340 individuals,with the highest site averaging over 90 individuals per autumn,making it one of the world’s top single-season counts and thus a globally important site for this species.We found that 82% and 61% records from coastal sites were juveniles,significantly higher than inland sites(15% and 24%).Juveniles at all four sites exhibited markedly earlier median passage time than non-juveniles,with brief overlapping in their main migration periods.Both coastal sites are located on the tip of peninsulas stretching southwest,requiring long overwater flights if crossing the Bohai Bay or Beibu Gulf,which would be energetically demanding and increase mortality risk.Experienced individuals may have learned to avoid such terrain and subsequent detour,while juveniles are more prone to enter these peninsulas due to lack of experience and opportunities for social learning,or following other raptor species that are more capable of powered flight.Our findings highlight the importance of age and experience in migration route selection of large soaring birds.
文摘据估计,我国的页岩气可采储量高达20万亿～36万亿m3,虽然我国页岩气储量评估处于初级阶段,但仍然可以肯定我国是页岩气资源丰富的国家之一,如果都能开发,按当前的天然气年产量计算,可以开发200多年。目前国内外多家企业聚焦中国,逐鹿页岩气,页岩气有望成为我国常规能源替代品,页岩气的勘探开发必将对我国乃至世界能源格局产生重大影响。但是由于页岩气储层致密,渗透率低至纳达西级,若不采取特殊的增产措施难以实现商业开发。美国是目前唯一实现页岩气商业开采的国家,技术和商业模式都相当成熟,中海石油斥资10多亿美元收购了美国页岩气主产区Eagle Ford 33.3%的股份,该地区页岩气地质储量高达6 000亿m3,开发前景广阔。为提升我国页岩气总体水平,笔者率领技术专家深入考察了美国Eagle Ford页岩气项目,增进了对水平钻井与分段压裂等关键技术的了解,同时分析了相应扶持政策,对中国页岩气的勘探开发具有重要的参考价值。
文摘Eagle产品检测于7月16～18日在上海举办的第二十届中国国际加工，包装及印刷科技展览会上凭借其新产品系列进一步拓展中国市场。其中，Eagle^TM Tall PRO XSDV检测系统首次亮相，这是一款专为硬质容器而设计的检测系统，其检测效果比普通X光机高出50％。同时亮相展会的还有Eagle 2014年全新上市的金属检测机系列，专为检测铁、非铁及不锈钢污染物而设计，具有极高的灵敏度和极佳的稳定性。
