In this paper,we studied the wing root pivot joint’s radial load of a submersible airplane which imitates the locomotion of gannet’s Morus plunge-diving,by implementing a test device name Mimic-Gannet.The housing of...In this paper,we studied the wing root pivot joint’s radial load of a submersible airplane which imitates the locomotion of gannet’s Morus plunge-diving,by implementing a test device name Mimic-Gannet.The housing of the device was designed by mimicking the morphology of a living gannet,and the folding wings were realized by the mechanism of variable swept back wing.Then,the radial loads of the wing root were obtained under the conditions of different dropping heights,different sweptback angles and different water-entry inclination angles(i.e.,the angle between the longitudinal body axis and the water surface),and the relationships between the peak radial load and the above three parameters were analyzed and discussed respectively.In the studied areas,the minimum peak radial load of the pivot joint is 50.93 N,while the maximum reaches up to1135.00 N.The largest peak load would be generated for the situation of vertical water entry and zero wing sweptback angle.And it is of great significance to choose the three parameters properly to reduce the pivot joint’s radial load,i.e.,larger wing sweptback angle,smaller dropping height and water-entry inclination angle.It is also concluded that the peak radial load on the wing root is closely linear with the water-entry dropping height and the wing sweptback angle with a significant correlation.Eventually,the relationship between the wing load and the dropping height,water-entry inclination angle or wing sweptback angle,could be used to calculate the wing load about plunge-diving of a submersible aircraft,and the conclusions reveal the wing load characteristic of the gannet’s plunge process for the biologists.展开更多
In the highly fragmented landscape of central Europe, dispersal is of particular importance as it determines the long-term survival of animal populations. Dispersal not only secures the recolonization of patches where...In the highly fragmented landscape of central Europe, dispersal is of particular importance as it determines the long-term survival of animal populations. Dispersal not only secures the recolonization of patches where populations went extinct, it may also rescue small populations and thus prevent local extinction events. As dispersal involves different individual fitness costs, the decision to disperse should not be random but context- dependent and often will be biased toward a certain group of individuals （e.g., sex- and wing morph-biased dispersal）. Although biased dispersal has far-reaching consequences for animal populations, immediate studies of sex- and wing morph-biased dispersal in orthopterans are very rare. Here, we used a combined approach of morphological and genetic analyses to investigate biased dispersal of Metrioptera bicolor, a wing dimorphic bush-cricket. Our results clearly show wing morph-biased dispersal for both sexes of M. bicolor. In addition, we found sex-biased dispersal for macropterous individuals, but not for micropters. Both, morphological and genetic data, favor macropterous males as dispersal unit of this bush-cricket species. To get an idea of the flight ability ofM. bicolor, we compared our morphological data with that of Locusta migratoria and Schistocerca gregaria, which are very good flyers. Based on our morphological data, we suggest a good flight ability for macropters of M. bicolor, although flying individuals of this species are seldom observed.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51005008)
文摘In this paper,we studied the wing root pivot joint’s radial load of a submersible airplane which imitates the locomotion of gannet’s Morus plunge-diving,by implementing a test device name Mimic-Gannet.The housing of the device was designed by mimicking the morphology of a living gannet,and the folding wings were realized by the mechanism of variable swept back wing.Then,the radial loads of the wing root were obtained under the conditions of different dropping heights,different sweptback angles and different water-entry inclination angles(i.e.,the angle between the longitudinal body axis and the water surface),and the relationships between the peak radial load and the above three parameters were analyzed and discussed respectively.In the studied areas,the minimum peak radial load of the pivot joint is 50.93 N,while the maximum reaches up to1135.00 N.The largest peak load would be generated for the situation of vertical water entry and zero wing sweptback angle.And it is of great significance to choose the three parameters properly to reduce the pivot joint’s radial load,i.e.,larger wing sweptback angle,smaller dropping height and water-entry inclination angle.It is also concluded that the peak radial load on the wing root is closely linear with the water-entry dropping height and the wing sweptback angle with a significant correlation.Eventually,the relationship between the wing load and the dropping height,water-entry inclination angle or wing sweptback angle,could be used to calculate the wing load about plunge-diving of a submersible aircraft,and the conclusions reveal the wing load characteristic of the gannet’s plunge process for the biologists.
文摘In the highly fragmented landscape of central Europe, dispersal is of particular importance as it determines the long-term survival of animal populations. Dispersal not only secures the recolonization of patches where populations went extinct, it may also rescue small populations and thus prevent local extinction events. As dispersal involves different individual fitness costs, the decision to disperse should not be random but context- dependent and often will be biased toward a certain group of individuals （e.g., sex- and wing morph-biased dispersal）. Although biased dispersal has far-reaching consequences for animal populations, immediate studies of sex- and wing morph-biased dispersal in orthopterans are very rare. Here, we used a combined approach of morphological and genetic analyses to investigate biased dispersal of Metrioptera bicolor, a wing dimorphic bush-cricket. Our results clearly show wing morph-biased dispersal for both sexes of M. bicolor. In addition, we found sex-biased dispersal for macropterous individuals, but not for micropters. Both, morphological and genetic data, favor macropterous males as dispersal unit of this bush-cricket species. To get an idea of the flight ability ofM. bicolor, we compared our morphological data with that of Locusta migratoria and Schistocerca gregaria, which are very good flyers. Based on our morphological data, we suggest a good flight ability for macropters of M. bicolor, although flying individuals of this species are seldom observed.
