Solar-driven water splitting for photocatalytic hydrogen evolution is considered a highly promising and costeffective solution to achieve a stable renewable energy supply.However,the sluggish kinetics of electron-hole...Solar-driven water splitting for photocatalytic hydrogen evolution is considered a highly promising and costeffective solution to achieve a stable renewable energy supply.However,the sluggish kinetics of electron-hole pairs’separation poses challenges in attaining satisfactory hydrogen production efficiency.Herein,we synthesized the exceptional performance of highly crystalline C_(3)N_(5)(HC–C_(3)N_(5))nanosheet as a photocatalyst,demonstrating a remarkable hydrogen evolution rate of 3.01 mmol h^(-1)g^(-1),which surpasses that of bulk C_(3)N_(5)(B–C_(3)N_(5))by a factor of 3.27.Experimental and theoretical analyses reveal that HC-C_(3)N_(5)nanosheets exhibit intriguing macroscopic photoinduced color changes,effectively broadening the absorption spectrum and significantly enhancing the generation of excitons.Besides,the cyano groups in HC-C_(3)N_(5)efficiently captures and converts photoexcited electrons into bound states,thereby prolonging their lifetimes and effectively separating electrons and holes into catalytically active regions.This research provides valuable insights into the establishment of bound electronic states for developing efficient photocatalysts.展开更多
Under investigation in this paper is a complex modified Korteweg–de Vries(KdV) equation, which describes the propagation of short pulses in optical fibers. Bilinear forms and multi-soliton solutions are obtained thro...Under investigation in this paper is a complex modified Korteweg–de Vries(KdV) equation, which describes the propagation of short pulses in optical fibers. Bilinear forms and multi-soliton solutions are obtained through the Hirota method and symbolic computation. Breather-like and bound-state solitons are constructed in which the signs of the imaginary parts of the complex wave numbers and the initial separations of the two parallel solitons are important factors for the interaction patterns. The periodic structures and position-induced phase shift of some solutions are introduced.展开更多
The measurement of the bound-state decay of^(205)Tl at the Experimental Storage Ring(ESR)at GSI,Darmstadt,has recently been reported,with substantial impact on the use of^(205)Pb as an early Solar System chronometer a...The measurement of the bound-state decay of^(205)Tl at the Experimental Storage Ring(ESR)at GSI,Darmstadt,has recently been reported,with substantial impact on the use of^(205)Pb as an early Solar System chronometer and on the low-energy measurement of the solar neutrino spectrum via the LOREX project.Owing to the technical challenges in producing a high-purity^(205)T^(l81+)secondary beam,a robust statistical method was developed to estimate the variation in the contaminant^(205)Pb^(81+)produced in the fragmentation reaction,which was subsequently transmitted and stored in the ESR.Here,we show that Bayesian and Monte Carlo methods produce comparable estimates for the contaminant variation,each with unique advantages and challenges given the complex statistical problems for this experiment.We recommend the adoption of such methods in future experiments that exhibit unknown statistical fluctuations.展开更多
In this work,we investigate the thermodynamic variables of a harmonic oscillator in a conical geometry metric.Moreover,we introduce an external field in the form of a Wu-Yang magnetic monopole(WYMM)and an inverse squa...In this work,we investigate the thermodynamic variables of a harmonic oscillator in a conical geometry metric.Moreover,we introduce an external field in the form of a Wu-Yang magnetic monopole(WYMM)and an inverse square potential into the system and analyze the results.Using an analytical approach,we obtain the energy level and study the thermodynamics at finite temperature.Our findings demonstrate that thermodynamic variables,except for the specific heat and entropy,are influenced by the topological parameters,the strength of the WYMM,and the inverse square potential.展开更多
与传统的光子晶体或超表面等微纳光学系统相比,基于连续域束缚态(bound states in the continuum,BIC)的光学体系通常具有更高的品质因子(quality factor,Q)与更窄的工作线宽,更高的Q值给高性能的光电元件提供了更广阔的可能性,但是更...与传统的光子晶体或超表面等微纳光学系统相比,基于连续域束缚态(bound states in the continuum,BIC)的光学体系通常具有更高的品质因子(quality factor,Q)与更窄的工作线宽,更高的Q值给高性能的光电元件提供了更广阔的可能性,但是更窄的线宽往往给实际应用造成一定麻烦,因为加工过程中的制造误差无可避免地导致实际的光学元件与理想情况存在差异,表现为实际工作波长与理想工作波长不匹配.为了克服该问题,本文利用带十字结构孔的光子晶体产生的对称保护型准连续域束缚态(quasi-bound states in the continuum,q-BIC),探索液晶(liquid crystal,LC)对q-BIC的动态调谐效应,以补偿加工误差导致的工作波长偏移.相比于入射光倾斜角对q-BIC的调制效应,在移动相同的波长时,LC对系统的Q值影响更小,例如使用入射光倾斜角调制q-BIC中心波长移动5.32 nm时,Q值下降75.84%,而使用LC调制q-BIC中心波长移动5.63 nm时,Q值上升了14.27%,这证明LC对高Q因子、超窄带的q-BIC元件具有极大的应用潜力.最后讨论了LC在q-BIC体系中的工作机理,可为广泛q-BIC的相关研究提供参考.展开更多
激光器在信息通信、智能制造等关键技术中发挥着核心作用。然而,传统半导体激光器尽管结构紧凑、效率高,却面临品质因子(Quality Factor,简称Q值)有限、光束质量较差及难以实现特殊光场等瓶颈。连续域中束缚态(Bound States in the Cont...激光器在信息通信、智能制造等关键技术中发挥着核心作用。然而,传统半导体激光器尽管结构紧凑、效率高,却面临品质因子(Quality Factor,简称Q值)有限、光束质量较差及难以实现特殊光场等瓶颈。连续域中束缚态(Bound States in the Continuum,BIC)是一种存在于辐射连续谱中的局域模态,因其与辐射通道完全解耦,可实现能量完全局域化,理论上具备无限大的Q值。基于BIC的激光器兼具高Q值与高局域化效应,能有效降低激光阈值,并显著抑制多模竞争从而输出高纯度单模激光。当前研究聚焦于通过结构设计提升BIC模式的稳定性与耦合效率,并探索其在集成光子学、拓扑激光器等前沿方向的应用。未来,BIC激光器有望在片上集成、主动调控等方面取得突破,推动高性能激光技术的发展。展开更多
本研究提出了一种基于连续域束缚态(bound states in the continuum,BIC)的全介质太赫兹超表面。超表面的每个结构单元由两个横截面为正方形的矩形块和衬底组成。衬底材料为石英,表面矩形块材料为无折射率损耗的硅。矩形块横截面面积的...本研究提出了一种基于连续域束缚态(bound states in the continuum,BIC)的全介质太赫兹超表面。超表面的每个结构单元由两个横截面为正方形的矩形块和衬底组成。衬底材料为石英,表面矩形块材料为无折射率损耗的硅。矩形块横截面面积的改变破坏了超表面的对称性,激发了准BIC,得到了具有极窄线宽的谐振。采用有限元方法(finite element method,FEM)和控制变量法研究了不同非对称参数、结构参数和材料参数下的透射光谱。同时,对所提出的超表面的Q值进行了计算,其Q值可达1.1006×10^(4),高于列出的相关文献中的Q值。此外,该研究针对目前对全介质超表面等效参数的研究相对较少的局限性,利用S参数提取法计算并分析了所提出的超表面的等效参数,并从该角度初步研究了超表面的物理性质。展开更多
实空间中光子的局域化在基础研究和技术应用领域具有重要意义.连续域束缚态(bound states in the continuum,BICs)为光子的局域化提供了新的机制,其中最重要的方案之一是光子晶体.然而光子晶体在制备过程中会不可避免地引入误差和缺陷,...实空间中光子的局域化在基础研究和技术应用领域具有重要意义.连续域束缚态(bound states in the continuum,BICs)为光子的局域化提供了新的机制,其中最重要的方案之一是光子晶体.然而光子晶体在制备过程中会不可避免地引入误差和缺陷,动量空间表征可以分析加工误差和缺陷对于光子晶体能带特性的影响,进而指导光子晶体器件的设计和制备.本文设计了可见光波段的光子晶体,通过动量空间表征观测到了连续域准束缚态(quasi-BIC),从而在垂直方向上实现了对光子的高度局域化,并通过调整结构参数,实现了对光子晶体动量空间的特征调控.进一步设计不同周期光子晶体的横向异质结构,利用两者的能带套嵌实现了对光子水平方向上的局域化,以此制备了品质因子与模式体积之比达到6×10^(14) cm^(-3)的高品质光学微腔.本研究对于光子晶体的设计以及增强光与物质相互作用具有重要意义.展开更多
基金supported by the National Natural Science Foundation of China(No.22006057,21906072 and 21908115)Postgraduate Research&Practice Innovation Program of Jiangsu Province(China)(SJCX23_2197)Natural Science Foundation of Zhejiang Province of China(LY20E080014).
文摘Solar-driven water splitting for photocatalytic hydrogen evolution is considered a highly promising and costeffective solution to achieve a stable renewable energy supply.However,the sluggish kinetics of electron-hole pairs’separation poses challenges in attaining satisfactory hydrogen production efficiency.Herein,we synthesized the exceptional performance of highly crystalline C_(3)N_(5)(HC–C_(3)N_(5))nanosheet as a photocatalyst,demonstrating a remarkable hydrogen evolution rate of 3.01 mmol h^(-1)g^(-1),which surpasses that of bulk C_(3)N_(5)(B–C_(3)N_(5))by a factor of 3.27.Experimental and theoretical analyses reveal that HC-C_(3)N_(5)nanosheets exhibit intriguing macroscopic photoinduced color changes,effectively broadening the absorption spectrum and significantly enhancing the generation of excitons.Besides,the cyano groups in HC-C_(3)N_(5)efficiently captures and converts photoexcited electrons into bound states,thereby prolonging their lifetimes and effectively separating electrons and holes into catalytically active regions.This research provides valuable insights into the establishment of bound electronic states for developing efficient photocatalysts.
基金Project supported by the National Natural Science Foundation of China (Grant No. 12161061)the Fundamental Research Funds for the Inner Mongolia University of Finance and Economics (Grant No. NCYWT23036)+2 种基金the Young Innovative and Entrepreneurial Talents of the Inner Mongolia Grassland Talents Project in 2022,Autonomous Region “Five Major Tasks” Research Special Project for the Inner Mongolia University of Finance and Economics in 2024 (Grant No. NCXWD2422)High Quality Research Achievement Cultivation Fund for the Inner Mongolia University of Finance and Economics in 2024 (Grant No. GZCG2426)the Talent Development Fund of Inner Mongolia Autonomous Region, China。
文摘Under investigation in this paper is a complex modified Korteweg–de Vries(KdV) equation, which describes the propagation of short pulses in optical fibers. Bilinear forms and multi-soliton solutions are obtained through the Hirota method and symbolic computation. Breather-like and bound-state solitons are constructed in which the signs of the imaginary parts of the complex wave numbers and the initial separations of the two parallel solitons are important factors for the interaction patterns. The periodic structures and position-induced phase shift of some solutions are introduced.
基金funding from the European Research Council(ERC)under the European Union's Horizon 2020 research and innovation programme(Grant Agreement No.682841"ASTRUm"and No.654002"ENSAR2")The research of G.Leckenby,I.Dillmann,and C.Griffin was funded by the Canadian Natural Sciences and Engineering Research Council(NSERC)via the grant SAPIN-2019-00030+1 种基金J.Glorius,M.S.Sanjari,Yu.A.Litvinov and C.Brandau acknowledge support by the State of Hesse within the Research Cluster ELEMENTS(Project ID 500/10.006)E.Menz and Yu.A.Litvinov acknowledge support by the project"NRW-FAIR",a part of the programme"Netzwerke 2021",an initiative of the Ministry of Culture and Science of the State of North Rhine-Westphalia.R.Gernhäuser acknowledges support by the Excellence Cluster ORIGINS from the German Research Foundation DFG(Excellence Strategy EXC-2094-390783311)。
文摘The measurement of the bound-state decay of^(205)Tl at the Experimental Storage Ring(ESR)at GSI,Darmstadt,has recently been reported,with substantial impact on the use of^(205)Pb as an early Solar System chronometer and on the low-energy measurement of the solar neutrino spectrum via the LOREX project.Owing to the technical challenges in producing a high-purity^(205)T^(l81+)secondary beam,a robust statistical method was developed to estimate the variation in the contaminant^(205)Pb^(81+)produced in the fragmentation reaction,which was subsequently transmitted and stored in the ESR.Here,we show that Bayesian and Monte Carlo methods produce comparable estimates for the contaminant variation,each with unique advantages and challenges given the complex statistical problems for this experiment.We recommend the adoption of such methods in future experiments that exhibit unknown statistical fluctuations.
文摘In this work,we investigate the thermodynamic variables of a harmonic oscillator in a conical geometry metric.Moreover,we introduce an external field in the form of a Wu-Yang magnetic monopole(WYMM)and an inverse square potential into the system and analyze the results.Using an analytical approach,we obtain the energy level and study the thermodynamics at finite temperature.Our findings demonstrate that thermodynamic variables,except for the specific heat and entropy,are influenced by the topological parameters,the strength of the WYMM,and the inverse square potential.
文摘与传统的光子晶体或超表面等微纳光学系统相比,基于连续域束缚态(bound states in the continuum,BIC)的光学体系通常具有更高的品质因子(quality factor,Q)与更窄的工作线宽,更高的Q值给高性能的光电元件提供了更广阔的可能性,但是更窄的线宽往往给实际应用造成一定麻烦,因为加工过程中的制造误差无可避免地导致实际的光学元件与理想情况存在差异,表现为实际工作波长与理想工作波长不匹配.为了克服该问题,本文利用带十字结构孔的光子晶体产生的对称保护型准连续域束缚态(quasi-bound states in the continuum,q-BIC),探索液晶(liquid crystal,LC)对q-BIC的动态调谐效应,以补偿加工误差导致的工作波长偏移.相比于入射光倾斜角对q-BIC的调制效应,在移动相同的波长时,LC对系统的Q值影响更小,例如使用入射光倾斜角调制q-BIC中心波长移动5.32 nm时,Q值下降75.84%,而使用LC调制q-BIC中心波长移动5.63 nm时,Q值上升了14.27%,这证明LC对高Q因子、超窄带的q-BIC元件具有极大的应用潜力.最后讨论了LC在q-BIC体系中的工作机理,可为广泛q-BIC的相关研究提供参考.
文摘激光器在信息通信、智能制造等关键技术中发挥着核心作用。然而,传统半导体激光器尽管结构紧凑、效率高,却面临品质因子(Quality Factor,简称Q值)有限、光束质量较差及难以实现特殊光场等瓶颈。连续域中束缚态(Bound States in the Continuum,BIC)是一种存在于辐射连续谱中的局域模态,因其与辐射通道完全解耦,可实现能量完全局域化,理论上具备无限大的Q值。基于BIC的激光器兼具高Q值与高局域化效应,能有效降低激光阈值,并显著抑制多模竞争从而输出高纯度单模激光。当前研究聚焦于通过结构设计提升BIC模式的稳定性与耦合效率,并探索其在集成光子学、拓扑激光器等前沿方向的应用。未来,BIC激光器有望在片上集成、主动调控等方面取得突破,推动高性能激光技术的发展。
文摘本研究提出了一种基于连续域束缚态(bound states in the continuum,BIC)的全介质太赫兹超表面。超表面的每个结构单元由两个横截面为正方形的矩形块和衬底组成。衬底材料为石英,表面矩形块材料为无折射率损耗的硅。矩形块横截面面积的改变破坏了超表面的对称性,激发了准BIC,得到了具有极窄线宽的谐振。采用有限元方法(finite element method,FEM)和控制变量法研究了不同非对称参数、结构参数和材料参数下的透射光谱。同时,对所提出的超表面的Q值进行了计算,其Q值可达1.1006×10^(4),高于列出的相关文献中的Q值。此外,该研究针对目前对全介质超表面等效参数的研究相对较少的局限性,利用S参数提取法计算并分析了所提出的超表面的等效参数,并从该角度初步研究了超表面的物理性质。
文摘实空间中光子的局域化在基础研究和技术应用领域具有重要意义.连续域束缚态(bound states in the continuum,BICs)为光子的局域化提供了新的机制,其中最重要的方案之一是光子晶体.然而光子晶体在制备过程中会不可避免地引入误差和缺陷,动量空间表征可以分析加工误差和缺陷对于光子晶体能带特性的影响,进而指导光子晶体器件的设计和制备.本文设计了可见光波段的光子晶体,通过动量空间表征观测到了连续域准束缚态(quasi-BIC),从而在垂直方向上实现了对光子的高度局域化,并通过调整结构参数,实现了对光子晶体动量空间的特征调控.进一步设计不同周期光子晶体的横向异质结构,利用两者的能带套嵌实现了对光子水平方向上的局域化,以此制备了品质因子与模式体积之比达到6×10^(14) cm^(-3)的高品质光学微腔.本研究对于光子晶体的设计以及增强光与物质相互作用具有重要意义.
