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Tunable/Reconfigurable Metasurfaces: Physics and Applications

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Research 2019年第1期2019卷 806-821页

作者： qiong he Shulin Sun Lei Zhou State Key Laboratory of Surface Physics and Key Laboratory of Micro and Nano Photonic Structures(Ministry of Education)and Department of Physics Fudan UniversityShanghai 200438China Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing Green Photonics and Department of Optical Science and EngineeringFudan UniversityShanghai 200433China

Metasurfaces,ultrathin metamaterials constructed by planar meta-atoms with tailored electromagnetic(EM)responses,have attracted tremendous attention due to their exotic abilities to freely control EM *** active elements incorporated into metasurface designs,one can realize tunable and/or reconfgurable metadevices with functionalities controlled by external stimuli,opening a new platform to dynamically manipulate EM *** this article,we briefy review recent progress on tunable/reconfgurable metasurfaces,focusing on their working mechanisms and practical *** frst describe available approaches,categorized into diferent classes based on external stimuli applied,to realize homogeneous tunable/reconfgurable metasurfaces,which can ofer uniform manipulations on EM *** next summarize recent achievements on inhomogeneous tunable/reconfgurable metasurfaces with constitutional meta-atoms locally tuned by external knobs,which can dynamically control the wave-fronts of EM *** conclude this review by presenting our own perspectives on possible future directions and existing challenges in this fast developing feld.

关键词： tunable surfaces directions

Variable and Robust East Asian Monsoon Rainfall Response to El Nio over the Past 60 Years(1957–2016)

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Advances in Atmospheric Sciences 2017年第10期34卷 1235-1248页

作者： Bin WANG Juan LI qiong he Earth System Modeling Center Nanjing University of Information Science and Technology Department of Atmospheric Sciences and International Pacific Research Center University of Hawaii at Manoa

Severe flooding occurred in southern and northern China during the summer of 2016 when the 2015 super El Nio decayed to a normal condition. However, the mean precipitation during summer（June–July-August） 2016 does not show significant anomalies, suggesting that — over East Asia（EA） — seasonal mean anomalies have limited value in representing hydrological hazards. Scrutinizing season-evolving precipitation anomalies associated with 16 El Nio episodes during 1957–2016 reveals that, over EA, the spatiotemporal patterns among the four categories of El Nio events are quite variable, due to a large range of variability in the intensity and evolution of El Nio events and remarkable subseasonal migration of the rainfall anomalies. The only robust seasonal signal is the dry anomalies over central North China during the El Nio developing summer. Distinguishing strong and weak El Nio impacts is important. Only strong El Nio events can persistently enhance EA subtropical frontal precipitation from the peak season of El Nio to the ensuing summer, by stimulating intense interaction between the anomalous western Pacific anticyclone（WPAC） and underlying dipolar sea surface temperature anomalies in the Indo-Pacific warm pool, thereby maintaining the WPAC and leading to a prolonged El Nio impact on EA. A weak El Nio may also enhance the post-El Nio summer rainfall over EA, but through a different physical process： the WPAC re-emerges as a forced response to the rapid cooling in the eastern Pacific. The results suggest that the skillful prediction of rainfall over continental EA requires the accurate prediction of not only the strength and evolution of El Nio, but also the subseasonal migration of EA rainfall anomalies.

关键词： El Nio impact monsoon rainfall East Asian monsoon Asian monsoon precipitation variability monsoon– ocean interaction western Pacific subtropical high

Primary Results of New Rare Earth Materials for Hongti Grape

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Journal of Rare Earths 2004年第Z1期22卷 271-273页

作者： he qiong Gu Jiangyuan Wang Jiachen Fruit Tree Working Station of Huocheng County Xinjiang 835200 China Agricultural Technological Extend Station of Huocheng County Xinjiang 835200 China Beijing General Research Institates for Nonferous MexalsBeijing 100088 China

New rare earth (RE) materials including RE phosphate as base fertilizer, bioactive RE micro-fertilizer and RE entire plant nutrition agent as topdressing fertilizer are treated on Hongti *** result showes that the plant leaves become thicker, the color is dark green, the plant disease index is lower, and the sugar content significantly increases.

关键词： Hongti grape sugar content rare earths

High-efficiency surface plasmon meta-couplers: concept and microwave-regime realizations

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Light(Science & Applications) 2016年第1期5卷 876-881页

作者： Wujiong Sun qiong he Shulin Sun Lei Zhou State Key Laboratory of Surface Physics and Key Laboratory of Micro and Nano Photonic Structures(Ministry of Education) Fudan UniversityShanghai 200433China Collaborative Innovation Center of AdvancedMicrostructures Fudan UniversityShanghai 200433China Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing Green Photonics and Department of Optical Science and EngineeringFudan UniversityShanghai 200433China

Surface plasmon polaritons(SPPs)and their low-frequency counterparts(i.e.,spoof SPPs on artificial surfaces)have recently found numerous applications in photonics,but traditional devices to excite them(such as gratings and prism couplers)all suffer from problems of inherent low efficiency because the generated SPPs can decouple,returning to free space,and reflections at the device surface can never be ***,we propose a new SPP excitation scheme based on a transparent gradient metasurface and numerically demonstrate that it exhibits inherently high efficiency(~94%)because the designed meta-coupler suppresses both decoupling and surface *** a practical realization of this concept,we fabricated a meta-coupler for operation in the microwave regime and performed near-field and far-field experiments to demonstrate that the achieved excitation efficiency for spoof SPPs reaches~73%,which is several times higher than that achieved by other available devices in this frequency *** findings can motivate the design and fabrication of high-performance plasmonic devices to harvest light–matter interactions,particularly those related to spoof SPPs in the low-frequency domain.

关键词： metamaterial metasurface plasmonic coupler surface plasmon polariton

Multi-hybrid method for investigation of EM scattering from inhomogeneous object above a dielectric rough surface

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Science China(Physics,Mechanics & Astronomy) 2012年第10期55卷 1781-1790页

作者： LI Jie GUO LiXin he qiong WEI Bing School of Science Xidian UniversityXi'an 710071China National Supercomputing Center in Shenzhen Shenzhen 518055China

An iterative strategy combining Kirchhoff approximation （KA） method is presented in this paper to study the interactions between KA is applied to study scattering from underlying rough surfaces with the hybrid finite element-boundary integral （FE-BI） the inhomogeneous object and the underlying rough surface. whereas FE-BI deals with scattering from the above target. Both two methods use updated excitation sources. Huygens equivalence principle and an iterative strategy are employed to consider the multi-scattering effects. This hybrid FE-BI-KA scheme is an improved and generalized version of previous hybrid Kirchhoff approximation-method of moments （KA-MoM）. This newly presented hybrid method has the following advantages：（1） the feasibility of modeling multi-scale scattering problems （large scale underlying surface and small scale target）; （2） low memory requirement as in hybrid KA-MoM; （3） the ability to deal with scattering from inhomogeneous （including coated or layered） scatterers above rough surfaces. The numerical results are given to evaluate the accuracy of the multi-hybrid technique; the computing time and memory requirements consumed in specific numerical simulation of FE-BI-KA are compared with those of MoM. The convergence performance is analyzed by studying the iteration number variation caused by related parameters. Then bistatic scattering from inhomogeneous object of different configurations above dielectric Gaussian rough surface is calculated and the influences of dielectric compositions and surface roughness on the scattering pattern are discussed.

关键词： electromagnetic scattering hybrid method rough surface inhomogeneous target

Simultaneous removing SO_2 and NO by a new system containing cobalt complex

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Journal of Environmental Sciences 2006年第3期18卷 567-571页

作者： ZHOU Chun-qiong DENG Xian-he PAN Zhao-qun School of Chemical and Energy Engineering South China University of Technology Guangzhou 510640 China

Absorption and catalytic oxidation of nitric oxide can be achieved by using cobalt（Ⅲ） ethylenediamine （Co（en）3^3＋. When simultaneous absorbing SO2 and NO, the precipitation of Co2（SO3）3 will be yielded and the NO removal will be decreased. A new catalyst system using Co（en）3^3＋ coupled with urea has been developed to simultaneous remove NO and SO2 in the flue gas. NO is absorbed and catalytically oxidized to nitrite and nitrate by Co（en）3^3＋. The dissolved oxygen in scrubbing solution from the feed stream acts as oxidant. Urea restrains the precipitation of Co2（SO3）3 by oxidizing SO3^2-to SO4^2- as COSO4 is more soluble in water. The experimental results proved that nearly all SO3^2- can be oxidized to SO4^2- and the high NO and SO2 removal could be obtained with the new system. The NO removal is influenced by gas flow rate, the concentration of Co（en）3^3＋ and urea in the absorption solution, the temperature of the scrubbing solution and the content of oxygen in the flue gas. The low gas flow rate is favorable to increase the NO removal. The experiments proved that the NO removal could be maintained at more than 95% by the system of 0.02 mol/L Co（en）3^3＋ and 1% urea at 50℃ with 10% O2 in the flue gas.

关键词： simultaneous removing SO2 and NO, Co(en)33+ urea SO32- oxidation

Scatterings from surface plasmons to propagating waves at plasmonic discontinuities

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Science Bulletin 2019年第12期64卷 802-807页

作者： Fuxin Guan Shulin Sun Shiyi Xiao qiong he Lei Zhou Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education) and State Key Laboratory of Surface Physics Fudan UniversityShanghai 200433China Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing and Department of Optical Science and Engineering Fudan UniversityShanghai 200433China Key Laboratory of Specialty Fiber Optics and Optical Access Networks Joint International Research Laboratory of Specialty Fiber Optics and Advanced CommunicationShanghai Collaborative Innovation Center of Advanced Microstructures Nanjing 210093China

Surface plasmon polaritons (SPPs) and their low-frequency counterpart spoof SPPs have attracted intensive interests in sciences [1,2], due to their unprecedented capabilities to confine electromagnetic (EM) fields at deep-subwavelength scale, leading to many applications such as super-resolution imaging [3], plasmonic lasers [4], surfaced-enhanced Raman effect [5], plasmonic waveguides [6,7] or circuits [8], etc. In practice, scatterings of SPPs to propagating waves (PWs) are inevitable as SPPs encounter discontinuities (say, interfaces between two different plasmonic systems). Such scatterings can lead to undesired radiation losses which should be avoided, especially in those applications employing SPPs as information carriers (say, plasmonic waveguides and nano-circuits [6–8]). Meanwhile, SPP-PW scatterings can also be utilized to achieve certain desired functionalities. For example, one can purposely place a set of carefully designed scatters on a plasmonic surface to scatter SPPs, generating fascinating effects such as holograms, focusing, or even directional radiations [9,10]. However, theoretical understandings on the inherent physics governing SPP-PW scatterings are far from satisfactory. Without a simple picture on such processes, people usually have to rely on full-wave simulations to optimize the devices to either suppress or utilize the SPP-PW scatterings. Although several theoretical approaches were proposed to study the SPP transmission/ reflection behaviors at certain plasmonic interfaces [11,12], the SPP-PW scatterings are usually overlooked. Moreover, since PWs have infinite channels to transport in free space, it is difficult to derive an analytical formula to describe such SPP-PW processes.

关键词： Surface plasmon polaritons(SPPs) electromagnetic(EM) propagating waves(PWs)

Alkali Induced Morphology and Property Improvements of TiO_2 by Hydrothermal Treatment

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Journal of Wuhan University of Technology(Materials Science) 2008年第4期23卷 503-506页

作者： he qiong WEN Xianming MA Peihua DENG Xiaochuan Qinghai Institute of Salt Lakes Chinese Academy of Sciences Xining 810008 China Graduate School of Chinese Academy of Sciences Beijing 100039 China

Alkali induced morphology and property improvements of TiO2 by hydrothermal reaction were investigated. The products were characterized by SEM, TEM, XRD, TG, EDX, FT-IR and DRS. The results indicate that, with the phase transformation from anatase to rutile, the morphologies changed from high aggregated particles to nanofibers with the diameter of about 100 nm and the length up to several tens of micrometers, meanwhile the process is controllable by manipulating the nature of the alkali, alkalinity and hydrothermal temperature. DRS analysis shows the property improvement of the nanofibers in the UV-Vis light absorption compared with the raw materials, implying the products have potential application in photocatalysis.

关键词： rutile nanofiber hydrothermal photocatalysis

A brief analysis of spatial constitution and functional organization of museum architecture： A case study on museums in hefei

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Frontiers of Architectural Research 2013年第3期2卷 354-361页

作者： Zao Li qiong Wei Hao he College of Architecture and Art Hefei University of Technology Hefei 230601 China

Cuttural architecture, specially, museum architecture, is of significant social value and importance for the improvement of city image, and for the optimization of people＇s living environment. Consequently, it is significant to analyze such kind of architecture from various perspectives so as to explore its spatial constitution and functional organization. This paper generalizes and puts forward methodology to design interesting exhibition space, convenient traffic space and diversified rest space.

关键词： Museum architectureExhibition Space Traffic space Rest space