Bio-inspired jumping robots have emerged as a promising solution for traversing complex terrains inaccessible to conventional locomotion systems.Drawing upon the exceptional jumping kinematics observed in insects,rese...Bio-inspired jumping robots have emerged as a promising solution for traversing complex terrains inaccessible to conventional locomotion systems.Drawing upon the exceptional jumping kinematics observed in insects,researchers have developed multiple robotic prototypes mimicking biological propulsion mechanisms.However,the principal technological barrier resides in actuator systems,where current energy storage technologies suffer from inadequate energy density,fundamentally limiting takeoff velocity and jumping height.To overcome these limitations,we present a novel combustion-explosive propulsion system exhibiting high mass-specific energy release and rapid acceleration characteristics.By integrating this propulsion mechanism with a unique jumping leg structure,experimental validation through prototype testing demonstrated vertical leaps reaching 20 cm(1.67 times body length)under laboratory conditions,accompanied by comprehensive thermodynamic modeling using ABAQUS simulations that validated the effectiveness of this actuation system.The integrated design approach combines bionic structural design with combustible fuel formulations to offer new possibilities for the development of highly flexible robotic systems capable of negotiating obstacles in disaster response scenarios.展开更多
There is growing evidence to suggest that the black hole mass has been previously underestimated with the Hb line width for certain Active Galactic Nuclei (AGN). With the assumption of the flatter rather than isotropi...There is growing evidence to suggest that the black hole mass has been previously underestimated with the Hb line width for certain Active Galactic Nuclei (AGN). With the assumption of the flatter rather than isotropic velocity distribution of gases in the broad-line region of AGN, we investigated the properties of Narrow Line Seyfert 1 (NLS1) galaxies, like the black hole mass and the Eddington ratio, and compared with Broad Line Seyfert 1 (BLS1) galaxies. Since gamma-rays detected in a few NLS1s which favored a smaller viewing angle in NLS1s than BLS1s, with the projection effect, we estimated the relative black hole mass and Eddington ratio for NLS1s and BLS1s. The result implies that the NLS1s and BLS1s have similar black hole masses and Eddington ratios, peaked at a larger black hole mass and lower Eddington ratio for the NLS1s than thought before. Furthermore, with applying the correction factor 6 of average black hole mass as derived from the modeling of both optical and UV data in radio-loud NLS1s by Calderone et al., to the Xu et al. sample, we find that the NLS1s and BLS1s also show similar black hole masses and Eddington ratios, peaked at 2.0 × 107 solar masses and 0.12 (Eddington ratio) for the NLS1s. The relation due to the enhanced black hole masses of NLS1s is discussed. In addition, there seems to show a linear correlation between jet power and disk luminosity for the flat spectrum radio-loud NLS1 sample, which implies an accretion dominated rather than black hole spin dominated jet.展开更多
Graphene-based nanocatalysts have appealed much interest as advanced electrocatalysts toward energy conversion reactions due to their outstanding electrocatalytic performance from the distinctive chemical composites a...Graphene-based nanocatalysts have appealed much interest as advanced electrocatalysts toward energy conversion reactions due to their outstanding electrocatalytic performance from the distinctive chemical composites and strong synergistic effects.Aiming to better understand the role of graphene played in enhancing the catalytic performance and offer guidance for fabricating more efficient graphenebased electrocatalysts,we herein summarize the remarkable achievements of graphene-based electrocatalysts for energy-conversion-related reactions.Started by discussing applications of graphene in the electrocatalytic reactions,we have manifested the crucial role of graphene played in promoting the catalytic performance.Subsequently,many representative graphene-based catalyst hybrids for electrocatalytic reactions are also overviewed,showing many effective strategies for the fabrication of more efficient graphene-related materials for the practical application.Finally,the perspective insights and challenging issues are also concluded to provide directions for the future development.展开更多
There are many arguments about Hume in the history of philosophy,especially after Kant criticized Hume,Kant believed that there is no concept of“universality”in Hume’s ethics.By analyzing Hume’s text,this article ...There are many arguments about Hume in the history of philosophy,especially after Kant criticized Hume,Kant believed that there is no concept of“universality”in Hume’s ethics.By analyzing Hume’s text,this article points out that Hume also pursues“universality”,and his“universality”is a universality in the sense of usefulness.Not only does his ethics have the concept of universality,but Hume also pursues universality in the field of nature science.This is helpful for the academic community to re-recognize Hume and further promote the study of Hume.展开更多
With the possibility of large-area processing, the ZIF-8-coated mesh membranes with rough micro-/nanostructures and underwater superoleophobic properties were successfully fabricated at ambient temperature and pressur...With the possibility of large-area processing, the ZIF-8-coated mesh membranes with rough micro-/nanostructures and underwater superoleophobic properties were successfully fabricated at ambient temperature and pressure.These membranes exhibited excellent separation efficiency over 99.99% for various oil-water mixtures with the residual oil content in the collected water less than 4 ppm, and high water flux of 10.2×104 L m-2 h-1. Furthermore, the ZIF-8-coated mesh membrane displayed outstanding stability towards high temperature and various organic solvents immersion. More importantly, based on its facile fabrication method, this kind of ZIF-8-coated mesh membrane can be easily enlarged, which is critical for the practical oil-water separation applications.展开更多
基金supported by the National Natural Science Foundation of China(No.32270460).
文摘Bio-inspired jumping robots have emerged as a promising solution for traversing complex terrains inaccessible to conventional locomotion systems.Drawing upon the exceptional jumping kinematics observed in insects,researchers have developed multiple robotic prototypes mimicking biological propulsion mechanisms.However,the principal technological barrier resides in actuator systems,where current energy storage technologies suffer from inadequate energy density,fundamentally limiting takeoff velocity and jumping height.To overcome these limitations,we present a novel combustion-explosive propulsion system exhibiting high mass-specific energy release and rapid acceleration characteristics.By integrating this propulsion mechanism with a unique jumping leg structure,experimental validation through prototype testing demonstrated vertical leaps reaching 20 cm(1.67 times body length)under laboratory conditions,accompanied by comprehensive thermodynamic modeling using ABAQUS simulations that validated the effectiveness of this actuation system.The integrated design approach combines bionic structural design with combustible fuel formulations to offer new possibilities for the development of highly flexible robotic systems capable of negotiating obstacles in disaster response scenarios.
文摘There is growing evidence to suggest that the black hole mass has been previously underestimated with the Hb line width for certain Active Galactic Nuclei (AGN). With the assumption of the flatter rather than isotropic velocity distribution of gases in the broad-line region of AGN, we investigated the properties of Narrow Line Seyfert 1 (NLS1) galaxies, like the black hole mass and the Eddington ratio, and compared with Broad Line Seyfert 1 (BLS1) galaxies. Since gamma-rays detected in a few NLS1s which favored a smaller viewing angle in NLS1s than BLS1s, with the projection effect, we estimated the relative black hole mass and Eddington ratio for NLS1s and BLS1s. The result implies that the NLS1s and BLS1s have similar black hole masses and Eddington ratios, peaked at a larger black hole mass and lower Eddington ratio for the NLS1s than thought before. Furthermore, with applying the correction factor 6 of average black hole mass as derived from the modeling of both optical and UV data in radio-loud NLS1s by Calderone et al., to the Xu et al. sample, we find that the NLS1s and BLS1s also show similar black hole masses and Eddington ratios, peaked at 2.0 × 107 solar masses and 0.12 (Eddington ratio) for the NLS1s. The relation due to the enhanced black hole masses of NLS1s is discussed. In addition, there seems to show a linear correlation between jet power and disk luminosity for the flat spectrum radio-loud NLS1 sample, which implies an accretion dominated rather than black hole spin dominated jet.
基金This work was funded by the Natural Science Foundation of Hunan Province(2022JJ50296,2021JJ40430)the Foundation of Hunan Educational Committee(21C0645,20A389)the Science and Technology Plan Project of Huaihua City(2021R3129,2020R2203).
文摘Graphene-based nanocatalysts have appealed much interest as advanced electrocatalysts toward energy conversion reactions due to their outstanding electrocatalytic performance from the distinctive chemical composites and strong synergistic effects.Aiming to better understand the role of graphene played in enhancing the catalytic performance and offer guidance for fabricating more efficient graphenebased electrocatalysts,we herein summarize the remarkable achievements of graphene-based electrocatalysts for energy-conversion-related reactions.Started by discussing applications of graphene in the electrocatalytic reactions,we have manifested the crucial role of graphene played in promoting the catalytic performance.Subsequently,many representative graphene-based catalyst hybrids for electrocatalytic reactions are also overviewed,showing many effective strategies for the fabrication of more efficient graphene-related materials for the practical application.Finally,the perspective insights and challenging issues are also concluded to provide directions for the future development.
文摘There are many arguments about Hume in the history of philosophy,especially after Kant criticized Hume,Kant believed that there is no concept of“universality”in Hume’s ethics.By analyzing Hume’s text,this article points out that Hume also pursues“universality”,and his“universality”is a universality in the sense of usefulness.Not only does his ethics have the concept of universality,but Hume also pursues universality in the field of nature science.This is helpful for the academic community to re-recognize Hume and further promote the study of Hume.
基金financially supported by the National Natural Science Foundation of China (21571076, 21390394, 21571079 and 61701543)"111" project (B07016)+1 种基金the Ministry of Science and Technology of SINOPEC (A381)Open Projects of State Key Laboratory of Safety and Control for Chemicals (SKL-038)
文摘With the possibility of large-area processing, the ZIF-8-coated mesh membranes with rough micro-/nanostructures and underwater superoleophobic properties were successfully fabricated at ambient temperature and pressure.These membranes exhibited excellent separation efficiency over 99.99% for various oil-water mixtures with the residual oil content in the collected water less than 4 ppm, and high water flux of 10.2×104 L m-2 h-1. Furthermore, the ZIF-8-coated mesh membrane displayed outstanding stability towards high temperature and various organic solvents immersion. More importantly, based on its facile fabrication method, this kind of ZIF-8-coated mesh membrane can be easily enlarged, which is critical for the practical oil-water separation applications.
