A sandwich plate with a corrugation and auxetic honeycomb hybrid core is constructed,and its sound insulation and optimization are investigated.First,the motion governing equation of the sandwich plate is established ...A sandwich plate with a corrugation and auxetic honeycomb hybrid core is constructed,and its sound insulation and optimization are investigated.First,the motion governing equation of the sandwich plate is established by the third-order shear deformation theory(TSDT),and then combined with the fluid-structure coupling conditions,and the sound insulation is solved.The theoretical results are validated by COMSOL simulation results,and the effects of the structural parameter on the sound insulation are analyzed.Finally,the standard genetic algorithm is adopted to optimize the sound insulation of the sandwich plate.展开更多
High frequency sky wave communication suffers from poor performance including poor link quality and low link success rate. To enhance performance, diversity technology is proposed in the high frequency communication n...High frequency sky wave communication suffers from poor performance including poor link quality and low link success rate. To enhance performance, diversity technology is proposed in the high frequency communication network(HFCN) in this paper.First, we present the benefits and the challenges by introducing diversity technology into the existing HFCN. Secondly, to exploit the benefits fully and overcome the challenges, we propose a system structure suitable for deploying diversity technology in HFCN in large scale,based on the cloud radio access network and software defined network. Moreover, we present a general structure for the real-time updating frequency management system that plays a more important role especially when resource consuming(e.g., frequency) diversity technology is deployed. Thirdly, we investigate the key techniques enabling diversity technology deployment. Finally, we point out the future research directions to help the HFCN with diversity work more efficiently and intelligently.展开更多
Numerous atomically precise coinage metal nanoclusters have been synthesized,exhibiting diverse structures and promising properties for catalytic and other functional applications.However,silver nanoclusters featuring...Numerous atomically precise coinage metal nanoclusters have been synthesized,exhibiting diverse structures and promising properties for catalytic and other functional applications.However,silver nanoclusters featuring layered core structures remain largely unexplored,limiting investigations into the effects of atomic arrangements on catalytic functions.Herein,we report the synthesis and atomic level structure of a novel thiolate-phosphine co-stabilized silver nanocluster,Ag_(26)(SR)_(16)(DPPE)_(4)Cl_(2)(denoted as Ag_(26)),where SR is 3,5-bis(trifluoromethyl)benzenethiolate and DPPE is 1,2-bis(diphenylphosphino)ethane.Single-crystal X-ray diffraction analysis reveals that Ag26 comprises a three-layered Ag_(18)core,with each layer consisting of six silver atoms arranged in a distorted parallelogram configuration.This Ag18 core is stabilized by four Ag_(2)(SR)_(4)(DPPE)metal-ligand motifs and two chlorides.Notably,TiO_(2)-supported Ag_(26)nanoclusters(Ag_(26)/TiO_(2))demonstrated promising photocatalytic performance for solar-driven hydrogen production,achieving a hydrogen evolution rate of 2006μmol·g^(-1)·h^(-1),representing 16.2-and 6.5-fold enhancements compared to bare TiO_(2)support and similarly sized Ag_(25)/TiO_(2)nanoclusters,respectively.The layered atomic arrangement in the Ag_(26)core favorably regulates the energy level alignment with TiO_(2),leading to efficient photogenerated charge separation and enhanced catalytic activity.This work highlights the potential of structurally tailored silver nanoclusters and offers valuable insights for the design of advanced materials for energy conversion applications.展开更多
The analyses of returned samples and data from in situ and remote sensing observations have substantially advanced our understanding of the lunar internal structure since the Apollo era.Previous studies have confirmed...The analyses of returned samples and data from in situ and remote sensing observations have substantially advanced our understanding of the lunar internal structure since the Apollo era.Previous studies have confirmed that the Moon resembles a terrestrial planet with a layered core–mantle–crust structure,which formed in the early lunar differentiation initialized by a magma ocean.The important results on the early differentiation of the Moon derived from the ongoing analyses of lunar samples and geophysical data,and experimental studies with different initial conditions,are reviewed in this study.The outstanding problems in the early lunar differentiation,including the formation of the lunar anorthositic crust,the origin of lunar dichotomy,lunar mantle convection,the lunar interior interface,and the chronology of early differentiation,are highlighted and summarized.These unsolved questions may provide research directions for future studies of early differentiation of the Moon.The upcoming lunar exploration missions will return new samples and geophysical data.Comprehensive analyses of the returned samples and the geophysical data(seismology,gravity and topography,and crustal magnetic field),coupled with experimental studies,could provide important results to answer the unsolved questions and constrain the early lunar differentiation.展开更多
基金Project supported by the National Natural Science Foundation of China (Nos. 12172339 and 11732005)the Beijing Natural Science Foundation of China (No. 1222006)。
文摘A sandwich plate with a corrugation and auxetic honeycomb hybrid core is constructed,and its sound insulation and optimization are investigated.First,the motion governing equation of the sandwich plate is established by the third-order shear deformation theory(TSDT),and then combined with the fluid-structure coupling conditions,and the sound insulation is solved.The theoretical results are validated by COMSOL simulation results,and the effects of the structural parameter on the sound insulation are analyzed.Finally,the standard genetic algorithm is adopted to optimize the sound insulation of the sandwich plate.
基金supported by the National Science Foundation of China under Grants No. 61801492 and No. 61601490a national major specific project governed by the national development and reform commission of China
文摘High frequency sky wave communication suffers from poor performance including poor link quality and low link success rate. To enhance performance, diversity technology is proposed in the high frequency communication network(HFCN) in this paper.First, we present the benefits and the challenges by introducing diversity technology into the existing HFCN. Secondly, to exploit the benefits fully and overcome the challenges, we propose a system structure suitable for deploying diversity technology in HFCN in large scale,based on the cloud radio access network and software defined network. Moreover, we present a general structure for the real-time updating frequency management system that plays a more important role especially when resource consuming(e.g., frequency) diversity technology is deployed. Thirdly, we investigate the key techniques enabling diversity technology deployment. Finally, we point out the future research directions to help the HFCN with diversity work more efficiently and intelligently.
基金the financial support by the Research Center Program of the IBS(IBS-R006-D1)in Republic of Korea.
文摘Numerous atomically precise coinage metal nanoclusters have been synthesized,exhibiting diverse structures and promising properties for catalytic and other functional applications.However,silver nanoclusters featuring layered core structures remain largely unexplored,limiting investigations into the effects of atomic arrangements on catalytic functions.Herein,we report the synthesis and atomic level structure of a novel thiolate-phosphine co-stabilized silver nanocluster,Ag_(26)(SR)_(16)(DPPE)_(4)Cl_(2)(denoted as Ag_(26)),where SR is 3,5-bis(trifluoromethyl)benzenethiolate and DPPE is 1,2-bis(diphenylphosphino)ethane.Single-crystal X-ray diffraction analysis reveals that Ag26 comprises a three-layered Ag_(18)core,with each layer consisting of six silver atoms arranged in a distorted parallelogram configuration.This Ag18 core is stabilized by four Ag_(2)(SR)_(4)(DPPE)metal-ligand motifs and two chlorides.Notably,TiO_(2)-supported Ag_(26)nanoclusters(Ag_(26)/TiO_(2))demonstrated promising photocatalytic performance for solar-driven hydrogen production,achieving a hydrogen evolution rate of 2006μmol·g^(-1)·h^(-1),representing 16.2-and 6.5-fold enhancements compared to bare TiO_(2)support and similarly sized Ag_(25)/TiO_(2)nanoclusters,respectively.The layered atomic arrangement in the Ag_(26)core favorably regulates the energy level alignment with TiO_(2),leading to efficient photogenerated charge separation and enhanced catalytic activity.This work highlights the potential of structurally tailored silver nanoclusters and offers valuable insights for the design of advanced materials for energy conversion applications.
基金supported by a National Natural Science Foundation of China(NSFC)grant(42125303)the B-type Strategic Priority Program of the Chinese Academy of Sciences(XDB41000000)the Natural Science Foundation of Henan Province(232300420174).
文摘The analyses of returned samples and data from in situ and remote sensing observations have substantially advanced our understanding of the lunar internal structure since the Apollo era.Previous studies have confirmed that the Moon resembles a terrestrial planet with a layered core–mantle–crust structure,which formed in the early lunar differentiation initialized by a magma ocean.The important results on the early differentiation of the Moon derived from the ongoing analyses of lunar samples and geophysical data,and experimental studies with different initial conditions,are reviewed in this study.The outstanding problems in the early lunar differentiation,including the formation of the lunar anorthositic crust,the origin of lunar dichotomy,lunar mantle convection,the lunar interior interface,and the chronology of early differentiation,are highlighted and summarized.These unsolved questions may provide research directions for future studies of early differentiation of the Moon.The upcoming lunar exploration missions will return new samples and geophysical data.Comprehensive analyses of the returned samples and the geophysical data(seismology,gravity and topography,and crustal magnetic field),coupled with experimental studies,could provide important results to answer the unsolved questions and constrain the early lunar differentiation.
