Heterostructure construction has become increasingly recognized as an effective strategy to enhance oxygen evolution reaction(OER)performance due to the exposed active surfaces and improved mass/charge transfer.Inspir...Heterostructure construction has become increasingly recognized as an effective strategy to enhance oxygen evolution reaction(OER)performance due to the exposed active surfaces and improved mass/charge transfer.Inspired by natural plant structures,this study develops a unique moss-like amorphous/crystalline(CoB/CeO_(2))heterojunction.This distinctive moss-like morphology facilitates the formation of staggered sheet structures in the catalyst,providing more active sites and open channels for reaction intermediates and gas release.Benefiting from the hydrophilic properties offered by the moss-like morphology,CoB/CeO_(2) exhibits excellent OER catalytic performance in 1 M KOH,requiring only 247 mV at 100 mA cm^(-2).Physicochemical characterization and mechanistic studies reveal that the close nanoscale features between CoB and CeO_(2) create abundant binary interfaces,optimize the electronic configuration,induce changes in electronic states,and provide abundant defect sites,thereby enhancing charge transfer capabilities.This work presents a new paradigm for the design of efficient and durable OER electrocatalysts.展开更多
Understanding the internal structure of asteroids is crucial for deciphering their formation and establishing defenses against potential hazards.The Daocheng Radio Telescope(DART),a recently constructed interferometri...Understanding the internal structure of asteroids is crucial for deciphering their formation and establishing defenses against potential hazards.The Daocheng Radio Telescope(DART),a recently constructed interferometric array designed for low-frequency Sun imaging,presents a promising tool for probing asteroid interiors.With a substantial 1-km array aperture and an equivalent receiving area of approximately 8,850 m2,DART plays a vital role in diagnosing asteroid internal structures.This study introduces an electromagnetic wave scattering model tailored to asteroids within DART’s operational frequency range(150 to 450 MHz).Ground-based radar detection can unveil multiple facets of these celestial bodies by leveraging low-frequency waves’penetrating capabilities and capitalizing on asteroids’rotational dynamics.Through simulations capturing the characteristics of low-frequency waves traversing a layered model and interacting with internal structures,we propose an electromagnetic scattering model of asteroids.Our results underscore DART’s potential as a crucial instrument for discerning the internal structure of near-Earth objects.We first formulate an asteroid model through celestial impact models,dimensional analysis,and data fitting to achieve this.Subsequently,we derive an electromagnetic scattering model using geometric optics and a propagation model for lossy mediums.Simulations demonstrate that morphology and internal structure dictate the distribution of scattered waves,with forward and backscattered waves providing comprehensive internal structure information over a rotation cycle.Furthermore,we observe that alterations in electromagnetic wave frequency induce changes in the scattering characteristics,prompting the convenience of employing multiple frequencies for retrieving detailed information about an asteroid’s internal medium and structure.This multidimensional approach positions DART as a promising asset in advancing our understanding of asteroid interiors,offering valuable insights for scientific inquiry and hazard mitigation strategies.展开更多
基金sponsored by the National Key Research and Development Program(2021YFE0109800)the National Natural Science Foundation of China(52076126)+1 种基金the Science and Technology Committee of Shanghai Municipality(22010501500)the Key Laboratory of Clean Power Generation and Environmental Protection Technology in Mechanical Industry.
文摘Heterostructure construction has become increasingly recognized as an effective strategy to enhance oxygen evolution reaction(OER)performance due to the exposed active surfaces and improved mass/charge transfer.Inspired by natural plant structures,this study develops a unique moss-like amorphous/crystalline(CoB/CeO_(2))heterojunction.This distinctive moss-like morphology facilitates the formation of staggered sheet structures in the catalyst,providing more active sites and open channels for reaction intermediates and gas release.Benefiting from the hydrophilic properties offered by the moss-like morphology,CoB/CeO_(2) exhibits excellent OER catalytic performance in 1 M KOH,requiring only 247 mV at 100 mA cm^(-2).Physicochemical characterization and mechanistic studies reveal that the close nanoscale features between CoB and CeO_(2) create abundant binary interfaces,optimize the electronic configuration,induce changes in electronic states,and provide abundant defect sites,thereby enhancing charge transfer capabilities.This work presents a new paradigm for the design of efficient and durable OER electrocatalysts.
基金supported by the National Nature Science Foundation of China(grant no.42004139)High-Precision Localization Method for Near-Earth Asteroids(grant no.E32623A0)the Research Project of Civil Aerospace Technologies(grant no.KJSP2023020106).
文摘Understanding the internal structure of asteroids is crucial for deciphering their formation and establishing defenses against potential hazards.The Daocheng Radio Telescope(DART),a recently constructed interferometric array designed for low-frequency Sun imaging,presents a promising tool for probing asteroid interiors.With a substantial 1-km array aperture and an equivalent receiving area of approximately 8,850 m2,DART plays a vital role in diagnosing asteroid internal structures.This study introduces an electromagnetic wave scattering model tailored to asteroids within DART’s operational frequency range(150 to 450 MHz).Ground-based radar detection can unveil multiple facets of these celestial bodies by leveraging low-frequency waves’penetrating capabilities and capitalizing on asteroids’rotational dynamics.Through simulations capturing the characteristics of low-frequency waves traversing a layered model and interacting with internal structures,we propose an electromagnetic scattering model of asteroids.Our results underscore DART’s potential as a crucial instrument for discerning the internal structure of near-Earth objects.We first formulate an asteroid model through celestial impact models,dimensional analysis,and data fitting to achieve this.Subsequently,we derive an electromagnetic scattering model using geometric optics and a propagation model for lossy mediums.Simulations demonstrate that morphology and internal structure dictate the distribution of scattered waves,with forward and backscattered waves providing comprehensive internal structure information over a rotation cycle.Furthermore,we observe that alterations in electromagnetic wave frequency induce changes in the scattering characteristics,prompting the convenience of employing multiple frequencies for retrieving detailed information about an asteroid’s internal medium and structure.This multidimensional approach positions DART as a promising asset in advancing our understanding of asteroid interiors,offering valuable insights for scientific inquiry and hazard mitigation strategies.
