In this study, we investigated the spatial aggregation of old and incipient nests of Atta sexdens rubropilosa by fitting Poisson and Negative binomial models to nest abundance data. Our aim is to analyse the distribut...In this study, we investigated the spatial aggregation of old and incipient nests of Atta sexdens rubropilosa by fitting Poisson and Negative binomial models to nest abundance data. Our aim is to analyse the distribution of ant nests in eucalypt regrowth, Cerrado and native forest fragment. We also investigated the correlation between nest abundance and climatic factors, as well as different nest ages. When comparing nests of different ages we observed an aggregated pattern for both old and incipient nests. On the other hand, analysing the distribution of nests separately, only taking into account the different areas and respective borders, old nests exhibited an aggregated pattern and incipient nests showed a random pattern, except for native forest with ants exhibiting only an aggregated pattern. The levels of aggregation changed in response to different areas and border gradients, with more external borders showing higher aggregation than more internal borders. Temperature was the variable showing the highest correlation with nest abundance and the correlation between nests of different ages was totally depending on the different areas.展开更多
Integrating energy-storage devices(supercapacitors)and shape-deformation devices(actuators)advances the miniaturization and multifunctional development of soft robots.However,soft robots necessitate supercapacitors wi...Integrating energy-storage devices(supercapacitors)and shape-deformation devices(actuators)advances the miniaturization and multifunctional development of soft robots.However,soft robots necessitate supercapacitors with high energy-storage performance and actuators with excellent actuation capability.Here,inspired by ant nests,we present a porous structure fabricated by MXene-graphene-methylcellulose(M-GMC)composite,which overcomes the self-stacking of MXene nanosheets and offers a larger specific surface area.The porous structure provides more channels and active sites for electrolyte ions,resulting in high energy storage performance.The areal capacitance of the M-GMC electrode reaches up to 787.9 mF·cm^(−2),significantly superior to that of the pristine MXene electrode(449.1 mF·cm^(−2)).Moreover,the M-GMC/polyethylene bilayer composites with energy storage and multi-responsive actuation functions are developed.The M-GMC is used as the electrode and the polyethylene is used as the encapsulation layer of the quasi-solid-state supercapacitor.Meanwhile,the actuators fabricated by the bilayer composites can be driven by light or low voltage(≤9 V).The maximum bending curvature is up to 5.11 cm^(−1).Finally,a smart gripper and a fully encapsulated smart integrated circuit based on the M-GMC/polyethylene are designed.The smart gripper enables programmable control with multi-stage deformations.The applications realize the intelligence and miniaturization of soft robots.The ant-nest-inspired M-GMC composites would provide a promising development strategy for soft robots and smart integrated devices.展开更多
It was reported that hemispheric corrosion occurred in copper tubes in an acetic acid environment. When hemispheric corrosion occurred, corrosion could easily progress if water then flowed into the copper pipe, and co...It was reported that hemispheric corrosion occurred in copper tubes in an acetic acid environment. When hemispheric corrosion occurred, corrosion could easily progress if water then flowed into the copper pipe, and countermeasures were needed. Therefore, we studied the copper corrosion caused by acetic acid. The present work investigated the relationship between the corrosion form of copper and acetic acid concentration using phosphorous-deoxidized copper, and reported that hemispherical corrosion was observed at acetic acid concentrations of 0.01 to 1 vol.% (0.002 to 0.2 mol·L<sup>-1</sup>) in the immersion test. In this study, the effects of acetic acid and phosphate on copper corrosion were examined using oxygen-free copper in immersion tests. The results suggested that different concentrations of phosphate in acetic acid solutions and the presence or absence of acetic acid and phosphate affected the corrosion of copper, resulting in different corrosion forms and corrosion progress.展开更多
文摘In this study, we investigated the spatial aggregation of old and incipient nests of Atta sexdens rubropilosa by fitting Poisson and Negative binomial models to nest abundance data. Our aim is to analyse the distribution of ant nests in eucalypt regrowth, Cerrado and native forest fragment. We also investigated the correlation between nest abundance and climatic factors, as well as different nest ages. When comparing nests of different ages we observed an aggregated pattern for both old and incipient nests. On the other hand, analysing the distribution of nests separately, only taking into account the different areas and respective borders, old nests exhibited an aggregated pattern and incipient nests showed a random pattern, except for native forest with ants exhibiting only an aggregated pattern. The levels of aggregation changed in response to different areas and border gradients, with more external borders showing higher aggregation than more internal borders. Temperature was the variable showing the highest correlation with nest abundance and the correlation between nests of different ages was totally depending on the different areas.
基金supported by the National Natural Science Foundation of China(Nos.52373113 and 52302038)Natural Science Foundation of Fujian Province(Nos.2021J02012 and 2021J01186)Top Young Talents Program of Fujian Province and Open Research Fund Program of the State Key Laboratory of Low-Dimensional Quantum Physics(No.KF202214).
文摘Integrating energy-storage devices(supercapacitors)and shape-deformation devices(actuators)advances the miniaturization and multifunctional development of soft robots.However,soft robots necessitate supercapacitors with high energy-storage performance and actuators with excellent actuation capability.Here,inspired by ant nests,we present a porous structure fabricated by MXene-graphene-methylcellulose(M-GMC)composite,which overcomes the self-stacking of MXene nanosheets and offers a larger specific surface area.The porous structure provides more channels and active sites for electrolyte ions,resulting in high energy storage performance.The areal capacitance of the M-GMC electrode reaches up to 787.9 mF·cm^(−2),significantly superior to that of the pristine MXene electrode(449.1 mF·cm^(−2)).Moreover,the M-GMC/polyethylene bilayer composites with energy storage and multi-responsive actuation functions are developed.The M-GMC is used as the electrode and the polyethylene is used as the encapsulation layer of the quasi-solid-state supercapacitor.Meanwhile,the actuators fabricated by the bilayer composites can be driven by light or low voltage(≤9 V).The maximum bending curvature is up to 5.11 cm^(−1).Finally,a smart gripper and a fully encapsulated smart integrated circuit based on the M-GMC/polyethylene are designed.The smart gripper enables programmable control with multi-stage deformations.The applications realize the intelligence and miniaturization of soft robots.The ant-nest-inspired M-GMC composites would provide a promising development strategy for soft robots and smart integrated devices.
文摘It was reported that hemispheric corrosion occurred in copper tubes in an acetic acid environment. When hemispheric corrosion occurred, corrosion could easily progress if water then flowed into the copper pipe, and countermeasures were needed. Therefore, we studied the copper corrosion caused by acetic acid. The present work investigated the relationship between the corrosion form of copper and acetic acid concentration using phosphorous-deoxidized copper, and reported that hemispherical corrosion was observed at acetic acid concentrations of 0.01 to 1 vol.% (0.002 to 0.2 mol·L<sup>-1</sup>) in the immersion test. In this study, the effects of acetic acid and phosphate on copper corrosion were examined using oxygen-free copper in immersion tests. The results suggested that different concentrations of phosphate in acetic acid solutions and the presence or absence of acetic acid and phosphate affected the corrosion of copper, resulting in different corrosion forms and corrosion progress.
基金The Natural Science Foundation of China(Grant No.30671691)the National Science Foundation for Post-doctoral Scientists of China and the Foundation for Outstanding Young Faculty Members of Northwest A&F University
