The Beijing Swift(Apus apus pekinensis)is a typical cavity-nesting bird that often nests inside holes and crevices in old architectures.Direct observation of their breeding behaviour is challenging and their breeding ...The Beijing Swift(Apus apus pekinensis)is a typical cavity-nesting bird that often nests inside holes and crevices in old architectures.Direct observation of their breeding behaviour is challenging and their breeding ecology is thus poorly studied.In this study,we analysed light-level geolocation data collected from six Beijing Swifts for the first time.Our results showed that geolocators can make comprehensive inference of their incubation period and behaviour.As a cost-effective and non-invasive method,geolocators can not only facilitate discovering migration routes,but also can be widely applied in the study of avian reproductive behaviour,especially in cavity-nesting bird species.We further discussed the characteristics and merits of this method and compared with other conventional nest-monitoring methods in recording birds.展开更多
德国的APUS Zero Emission推出了i-2飞机,这是一款以氢燃料电池为动力的四座通用航空飞机。这款全新的双发飞机预计将在2024年底或2025年初进行首次飞行。APUS是2014年成立的航空设计公司,总部位于Strausberg,公司计划依据欧洲航空安全...德国的APUS Zero Emission推出了i-2飞机,这是一款以氢燃料电池为动力的四座通用航空飞机。这款全新的双发飞机预计将在2024年底或2025年初进行首次飞行。APUS是2014年成立的航空设计公司,总部位于Strausberg,公司计划依据欧洲航空安全局CS-23规定,在2027年将i-2飞机认证为正常类飞机,并预计在2028年将该飞机推向市场,预计售价约为110万美元。展开更多
Climate change can affect rainfall and temperature worldwide,and the ability of birds to react to these changes can be mirrored by studying population phenology and their breeding success.Some European species have ad...Climate change can affect rainfall and temperature worldwide,and the ability of birds to react to these changes can be mirrored by studying population phenology and their breeding success.Some European species have advanced arrival and breeding dates in response to local spring advancement,but conditions experienced during winter seasons may also affect arrival dates and subsequent breeding success.We utilized data collected from 1983 to 2020 in four colonies of Common Swift(Apus apus)in Northern Italy(5486 breeding attempts)to examine the variations of laying date and breeding success in relation to non-breeding conditions(previous winter in Africa)and local conditions in breeding period(spring).Climatic conditions were monitored using the North Atlantic Oscillation(NAO)and El Nino Southern Oscillation(ENSO)indices to describe conditions experienced in winter quarters and the local temperature and rainfall conditions of the breeding area.Common Swifts laid their eggs earlier in warmer springs,and this in turn had a positive effect on breeding success.We did not find evidence for any effects of African winter conditions on laying date nor on breeding success.However,because studies made in the same area have demonstrated a relationship of winter conditions(NAO)on individual survival,our data highlight the importance of considering environmental variables across the annual life cycle to understand variation in Common Swift populations.展开更多
为辅助APU(auxiliary power unit)的研发,以目前广泛应用的带负载压气机结构APU为研究对象,进行建模分析与研究.首先介绍了APU结构特点与调节规律,然后分析了负载压气机对APU共同工作的影响,最后采用部件法建立了该类型APU数学模型并设...为辅助APU(auxiliary power unit)的研发,以目前广泛应用的带负载压气机结构APU为研究对象,进行建模分析与研究.首先介绍了APU结构特点与调节规律,然后分析了负载压气机对APU共同工作的影响,最后采用部件法建立了该类型APU数学模型并设计仿真软件.以某型APU为对象,数值仿真与实际试车数据比较,结果表明所采用的建模方法是正确的,计算误差小于5%,所建立的模型能够满足工程需求.展开更多
基金funded by SHAN SHUI Conservation Centre,Beijing。
文摘The Beijing Swift(Apus apus pekinensis)is a typical cavity-nesting bird that often nests inside holes and crevices in old architectures.Direct observation of their breeding behaviour is challenging and their breeding ecology is thus poorly studied.In this study,we analysed light-level geolocation data collected from six Beijing Swifts for the first time.Our results showed that geolocators can make comprehensive inference of their incubation period and behaviour.As a cost-effective and non-invasive method,geolocators can not only facilitate discovering migration routes,but also can be widely applied in the study of avian reproductive behaviour,especially in cavity-nesting bird species.We further discussed the characteristics and merits of this method and compared with other conventional nest-monitoring methods in recording birds.
文摘德国的APUS Zero Emission推出了i-2飞机,这是一款以氢燃料电池为动力的四座通用航空飞机。这款全新的双发飞机预计将在2024年底或2025年初进行首次飞行。APUS是2014年成立的航空设计公司,总部位于Strausberg,公司计划依据欧洲航空安全局CS-23规定,在2027年将i-2飞机认证为正常类飞机,并预计在2028年将该飞机推向市场,预计售价约为110万美元。
文摘Climate change can affect rainfall and temperature worldwide,and the ability of birds to react to these changes can be mirrored by studying population phenology and their breeding success.Some European species have advanced arrival and breeding dates in response to local spring advancement,but conditions experienced during winter seasons may also affect arrival dates and subsequent breeding success.We utilized data collected from 1983 to 2020 in four colonies of Common Swift(Apus apus)in Northern Italy(5486 breeding attempts)to examine the variations of laying date and breeding success in relation to non-breeding conditions(previous winter in Africa)and local conditions in breeding period(spring).Climatic conditions were monitored using the North Atlantic Oscillation(NAO)and El Nino Southern Oscillation(ENSO)indices to describe conditions experienced in winter quarters and the local temperature and rainfall conditions of the breeding area.Common Swifts laid their eggs earlier in warmer springs,and this in turn had a positive effect on breeding success.We did not find evidence for any effects of African winter conditions on laying date nor on breeding success.However,because studies made in the same area have demonstrated a relationship of winter conditions(NAO)on individual survival,our data highlight the importance of considering environmental variables across the annual life cycle to understand variation in Common Swift populations.
文摘为辅助APU(auxiliary power unit)的研发,以目前广泛应用的带负载压气机结构APU为研究对象,进行建模分析与研究.首先介绍了APU结构特点与调节规律,然后分析了负载压气机对APU共同工作的影响,最后采用部件法建立了该类型APU数学模型并设计仿真软件.以某型APU为对象,数值仿真与实际试车数据比较,结果表明所采用的建模方法是正确的,计算误差小于5%,所建立的模型能够满足工程需求.
