Aluminum(Al) 2024 matrix composites reinforced with alumina short fibers(Al_2O_(3sf)) and silicon carbide particles(SiC_p) as wear-resistant materials were prepared by pressure infiltration in this study. Further, the...Aluminum(Al) 2024 matrix composites reinforced with alumina short fibers(Al_2O_(3sf)) and silicon carbide particles(SiC_p) as wear-resistant materials were prepared by pressure infiltration in this study. Further, the effect of Al_2O_(3sf) on the friction and wear properties of the as-synthesized composites was systematically investigated, and the relationship between volume fraction and wear mechanism was discussed. The results showed that the addition of Al_2O_(3sf), characterized by the ratio of Al_2O_(3sf) to SiC_p, significantly affected the properties of the composites and resulted in changes in wear mechanisms. When the volume ratio of Al_2O_(3sf) to SiC_p was increased from 0 to 1, the rate of wear mass loss(K_m) and coefficients of friction(COFs) of the composites decreased, and the wear mechanisms were abrasive wear and furrow wear. When the volume ratio was increased from 1 to 3, the COF decreased continuously; however, the K_m increased rapidly and the wear mechanism became adhesive wear.展开更多
As one of the recent advances of optics and photonics,plasmonics has enabled unprecedented optical designs.Having a vectorial configuration of surface plasmon field,metallic nanostructures offer efficient solutions in...As one of the recent advances of optics and photonics,plasmonics has enabled unprecedented optical designs.Having a vectorial configuration of surface plasmon field,metallic nanostructures offer efficient solutions in polarization control with a very limited sample thickness.Many compact polarization devices have been realized using such metallic nanostructures.However,in most of these devices,the functions were usually simple and limited to a few polarization states.Here,we demonstrated a plasmonic polarization generator that can reconfigure an input polarization to all types of polarization states simultaneously.The plasmonic polarization generator is based on the interference of the in-plane(longitudinal)field of the surface plasmons that gives rise to versatile near-field polarization states on a metal surface,which have seldom been considered in previous studies.With a well-designed nanohole array,the in-plane field of SPPs with proper polarization states and phases can be selectively scattered out to the desired light beams.A manifestation of eight focusing beams with well-routed polarizations was experimentally demonstrated.Our design offers a new route to achieve the full control of optical polarizations and possibly advance the development in photonic information processing.展开更多
The emergence of all-inorganic perovskite CsPbBr_(3)has ignited significant interest in optoelectronic devices,However,CsPbBr_(3)thin film-based photodetectors face performance limitations due to grain boundaries and ...The emergence of all-inorganic perovskite CsPbBr_(3)has ignited significant interest in optoelectronic devices,However,CsPbBr_(3)thin film-based photodetectors face performance limitations due to grain boundaries and defect density.To address these challenges,we introduce a novel typeⅡheterojunction photodetector utilizing CsPbBr_(3)micro wires(MWs)and CdS nanoribbons(NBs).Remarkably,this photodetector exhibits exceptional characteristics:a high on/off current ratio(1.07×10^(5)),a responsivity of up to 1.35×10^(4)A·W^(-1),specific detectivity of 5.94×10^(15)Jones,external quantum efficiency of2.83×10^(4)%and rapid response/recovery time(400μs/3 ms).These superior performances stem from the exceptional crystalline quality of CsPbBr_(3)MWs and CdS NBs,coupled with the establishment of a typeⅡband alignment at their interface.This configuration enables efficient carrier separation while suppressing recombination.Importantly,1D CsPbBr_(3)MW/CdS NB heterojunction photodetectors demonstrate reliable imaging capabilities under visible light illumination.Our findings present an innovative solution for high-performance perovskite-based photodetectors,holding promise for future commercial applications.展开更多
基金financially supported by the National Natural Science Foundation of China (No. 51374028)
文摘Aluminum(Al) 2024 matrix composites reinforced with alumina short fibers(Al_2O_(3sf)) and silicon carbide particles(SiC_p) as wear-resistant materials were prepared by pressure infiltration in this study. Further, the effect of Al_2O_(3sf) on the friction and wear properties of the as-synthesized composites was systematically investigated, and the relationship between volume fraction and wear mechanism was discussed. The results showed that the addition of Al_2O_(3sf), characterized by the ratio of Al_2O_(3sf) to SiC_p, significantly affected the properties of the composites and resulted in changes in wear mechanisms. When the volume ratio of Al_2O_(3sf) to SiC_p was increased from 0 to 1, the rate of wear mass loss(K_m) and coefficients of friction(COFs) of the composites decreased, and the wear mechanisms were abrasive wear and furrow wear. When the volume ratio was increased from 1 to 3, the COF decreased continuously; however, the K_m increased rapidly and the wear mechanism became adhesive wear.
基金This work was supported by the National Key Projects for Basic Researches of China(No.2012CB921501)and the National Natural Science Foundation of China(Nos.11174136,11322439,11321063,and 91321312)This work was also supported by the Dengfeng Project B and Outstanding Ph.D.candidate Program A of Nanjing University and the PAPD project of Jiangsu Higher Education Institutions.
文摘As one of the recent advances of optics and photonics,plasmonics has enabled unprecedented optical designs.Having a vectorial configuration of surface plasmon field,metallic nanostructures offer efficient solutions in polarization control with a very limited sample thickness.Many compact polarization devices have been realized using such metallic nanostructures.However,in most of these devices,the functions were usually simple and limited to a few polarization states.Here,we demonstrated a plasmonic polarization generator that can reconfigure an input polarization to all types of polarization states simultaneously.The plasmonic polarization generator is based on the interference of the in-plane(longitudinal)field of the surface plasmons that gives rise to versatile near-field polarization states on a metal surface,which have seldom been considered in previous studies.With a well-designed nanohole array,the in-plane field of SPPs with proper polarization states and phases can be selectively scattered out to the desired light beams.A manifestation of eight focusing beams with well-routed polarizations was experimentally demonstrated.Our design offers a new route to achieve the full control of optical polarizations and possibly advance the development in photonic information processing.
基金financially supported by the National Natural Science Foundation of China(Nos.11864046 and 11764046)the Basic Research Program of Yunnan Province(Nos.202001AT070064 and 202101AT070124)+1 种基金Spring City Plan:the Highlevel Talent Promotion and Training Project of Kunming(No.2022SCP005)Yunnan Expert Workstation(No.202205AF150008)。
文摘The emergence of all-inorganic perovskite CsPbBr_(3)has ignited significant interest in optoelectronic devices,However,CsPbBr_(3)thin film-based photodetectors face performance limitations due to grain boundaries and defect density.To address these challenges,we introduce a novel typeⅡheterojunction photodetector utilizing CsPbBr_(3)micro wires(MWs)and CdS nanoribbons(NBs).Remarkably,this photodetector exhibits exceptional characteristics:a high on/off current ratio(1.07×10^(5)),a responsivity of up to 1.35×10^(4)A·W^(-1),specific detectivity of 5.94×10^(15)Jones,external quantum efficiency of2.83×10^(4)%and rapid response/recovery time(400μs/3 ms).These superior performances stem from the exceptional crystalline quality of CsPbBr_(3)MWs and CdS NBs,coupled with the establishment of a typeⅡband alignment at their interface.This configuration enables efficient carrier separation while suppressing recombination.Importantly,1D CsPbBr_(3)MW/CdS NB heterojunction photodetectors demonstrate reliable imaging capabilities under visible light illumination.Our findings present an innovative solution for high-performance perovskite-based photodetectors,holding promise for future commercial applications.