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Geometric metasurface for polarization synthesis and multidimensional multiplexing of terahertz converged vortices

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Photonics Research 2022年第6期10卷 1517-1532页

作者： YANG ZHU BINBIN LU ZHIYUAN FAN FUYONG YUE xiaofei zang ALEXEI V.BALAKIN ALEXANDER P.SHKURINOV YIMING ZHU SONGLIN ZHUANG Terahertz Technology Innovation Research Institute Terahertz Spectrum and Imaging Technology Cooperative Innovation CenterShanghai Key Laboratory of Modern Optical SystemUniversity of Shanghai for Science and TechnologyShanghai 200093China Shanghai Institute of Intelligent Science and Technology Tongji UniversityShanghai 200092China Department of Physics Lomonosov Moscow State UniversityMoscow 119991Russia

The investigation of converged twisted beams with a helical phase structure has a remarkable impact on both fundamental physics and practical *** metasurfaces consisting of individually orientated metal/dielectric meta-atoms provide an ultracompact platform for generating converged ***,it is still challenging to simultaneously focus left-handed and right-handed circularly polarized incident beams with pure geometric phase modulation,which hinders the independent operation on topological charges between these two helical *** we propose and experimentally demonstrate an approach to design terahertz geometric metasurfaces that can generate helicity-independent converged vortices with homogeneous polarization states by the superposition of two orthogonal helical vortices with identical topological ***,the multiplexing of polarization-rotatable multiple vortices in multiple dimensions,i.e.,in both longitudinal and transverse directions,and a vortex with an extended focal depth is confirmed by embedding polarization modulation into the geometric *** demonstrated approach provides a new way to simultaneously manipulate orthogonal helical components and expand the design dimension,enabling new applications of geometric metasurface devices in polarization optics,twisted-beam related image and edge detection,high capacity optical communication,and quantum information processing,to name a few.

关键词： converge helical twisted

Dual-layered metasurfaces for asymmetric focusing

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Photonics Research 2020年第6期8卷 830-843页

作者： BINGSHUANG YAO xiaofei zang ZHEN L LIN CHEN JINGYA XIE YIMING ZHU SONGLIN ZHUANG Terahertz Technology Innovation Research Institute Terahertz Spectrum and Imaging Technology Cooperative Innovation CenterShanghai Key Laboratory of Moderm Optical SystemUniversity of Shanghai for Science and TechnologyShanghai 200093China Shanghai Institute of Intelligent Science and Technology Tongi UniversityShanghai 200092China

Asymmetric transmission,defined as the difference between the forward and backward transmission,enables a plethora of applications for on-chip integration and ***,the traditional method for asymmetric transmission is to control the propagation direction of the waves,hindering further ***,a kind of two-dimensional metamaterials,have shown an unprecedented ability to manipulate the propagation direction,phase,and polarization of electromagnetic *** we propose and experimentally demonstrate a metasurface-based directional device consisting of a geometric metasurface with spatially rotated microrods and metallic gratings,which can simultaneously control the phase,polarization,and propagation direction of waves,resulting in asymmetric focusing in the terahertz *** dual-layered metasurfaces for asymmetric focusing can work in a wide bandwidth ranging from 0.6 to 1.1 *** flexible and robust approach for designing broadband asymmetric focusing may open a new avenue for compact devices with potential applications in encryption,information processing,and communication.

关键词： asymmetric layered surfaces

Spin-decoupled metalens with intensity-tunable multiple focal points

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Photonics Research 2021年第6期9卷 1019-1032页

作者： BINGSHUANG YAO xiaofei zang YANG ZHU DAHAI YU JINGYA XIE LIN CHEN SEN HAN YIMING ZHU SONGLIN ZHUANG Terahertz Technology Innovation Research Institute Terahertz Spectrum and Imaging Technology Cooperative Innovation CenterShanghai Key Laboratory of Modern Optical SystemUniversity of Shanghai for Science and TechnologyShanghai 200093China Shanghai Institute of Intelligent Science and Technology Tongji UniversityShanghai 200092China Focused Photonics(Hangzhou)Inc Hangzhou 310052China Suzhou H&L Instruments LLC Suzhou 215123China

The control of spin electromagnetic(EM)waves is of great significance in optical *** geometric metasurfaces have shown unprecedented capability to manipulate the wavefronts of spin EM waves,it is still challenging to independently manipulate each spin state and intensity distribution,which inevitably degrades metasurface-based devices for further *** we propose and experimentally demonstrate an approach to designing spin-decoupled metalenses based on pure geometric phase,i.e.,geometric metasurfaces with predesigned phase modulation possessing functionalities of both convex lenses and concave *** the illumination of left-/right-handed circularly polarized(LCP or RCP)terahertz(THz)waves,these metalenses can generate transversely/longitudinally distributed RCP/LCP multiple focal *** the helicity-dependent multiple focal points are locked to the polarization state of incident THz waves,the relative intensity between two orthogonal components can be controlled with different weights of LCP and RCP THz waves,leading to the intensity-tunable *** robust approach for simultaneously manipulating orthogonal spin states and energy distributions of spin EM waves will open a new avenue for designing multifunctional devices and integrated communication systems.

关键词： intensity designing illumination

Deployment analysis of composite thin-walled lenticular tubes with effect of storage time and temperature

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Chinese Journal of Aeronautics 2024年第1期37卷 162-172页

作者： Jinfeng DENG Ning AN Qilong JIA xiaofei MA School of Aeronautics and Astronautics Sichuan UniversityChengdu 610065China State Key Laboratory for Strength and Vibration of Mechanical Structures School of AerospaceXi’an Jiaotong UniversityXi’an 710049China State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of TechnologyDalian 116024China Xi’an Institute of Space Radio Technology Xi’an 710100China

Composite Thin-walled Lenticular Tube(CTLT)is increasingly utilized in small satellites missions as a lightweight,foldable,and rollable structural material that facilitates the construction of large deployable *** CTLT is initially flattened and coiled around a central hub for storage before launch,during which elastic energy is stored as deformation energy,allowing it to be self-deployed on demand for use in *** work presents a comprehensive investigation into the coiling,storage and deployment behaviors of CTLT that wraps around a central hub.A nonlinear explicit dynamic finite element model was developed with both deformable CTLT and rigidbodies mechanisms including the central hub and guide rollers,as well as the complex interactions among *** coiling mechanics characteristics such as stored strain energy and rotational moment were presented and validated against experimental data in the ***,the dynamic deployment behaviors were analyzed in terms of two different deployment methods,namely,controlled deployment and free *** effect of material property change during storage was also discussed through numerical experiments.

关键词： Composite deployable structures Deployment dynamics Finite element method Stress relaxation Thin-walled booms

Mode splitting transmission effect of surface wave excitation through a metal hole array

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Light(Science & Applications) 2013年第1期2卷 192-196页

作者： Lin Chen Yiming Zhu xiaofei zang Bin Cai Zhou Li Le Xie Songlin Zhuang Engineering Research Center of Optical Instrument and System Ministry of EducationShanghai Key Lab of Modern Optical SystemUniversity of Shanghai for Science and TechnologyShanghai 200093China

The resonant frequencies of the excited surface waves on a metal hole array with respect to the incident angle were studied in the terahertz *** experimental and theoretical results demonstrate that the resonant peak of surface wave excitation splits into two when transmitted through a metal hole array *** high-order mode with resonant frequency above the cutoff frequency fc(plasma frequency effect)has a shorter attenuation length than that of the low-order mode whose resonant frequency is below *** reason is that the high-order mode is a coupled mode consisting of surface wave and hole modes,while the low-order mode is just an excited surface wave(which can be considered as the spoof surface plasmons).Our investigation may open a door to distinguish the spoof surface plasmons and the coupled modes of surface waves and hole modes.

关键词： angular dependence cutoff frequency metal hole arrays surface waves terahertz

Quantum correlations in a chain-type quantum network

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Communications in Theoretical Physics 2024年第6期76卷 77-91页

作者： xiaofei Qi Aihong Zhai Lihua Yang School of Mathematical Science Shanxi UniversityTaiyuan 030006China Key Laboratory of Complex Systems and Data Science of Ministry of Education Shanxi UniversityTaiyuan 030006China School of Mathematics and Information Technology Yuncheng UniversityYuncheng 044000China

A quantum network concerns several independent entangled resources and can create strong quantum correlations by performing joint measurements on some *** this paper,we discuss an n-partite chain network with each of two neighboring observers sharing an arbitrary Bell state and all intermediate observers performing some positive-operator-valued measurements with parameterλ.The expressions of all post-measurement states between any two observers are obtained,and their quantifications of Bell nonlocality,Einstein-Podolsky-Rosen steering and entanglement with different ranges ofλare respectively detected and analyzed.

关键词： quantum correlation nonlocality entanglement chain-type quantum network

Deciphering the cellular heterogeneity of the insect brainwith single-cell RNA sequencing

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Insect Science 2024年第2期31卷 314-327页

作者： xiaofei Wang Yifan Zhai Hao Zheng Institute of Plant Protection Shandong Academy of Agricultural SciencesJinanChina College of Food Science and Nutritional En-gineering China Agricultural UniversityBeijingChina Key Laboratory of Natural Enemies Insects Ministry of Agriculture and RuralAffairsJinanChina Shandong Provincial Engineering Technology Research Center on Biocontrol of Crops Diseases and In-sectPests JinanChina

Insects show highly complicated adaptive and sophisticated behaviors, includ-ing spatial orientation skills, learning ability, and social interaction. These behaviors arecontrolled by the insect brain, the central part of the nervous system. The tiny insect brainconsists of millions of highly differentiated and interconnected cells forming a complexnetwork. Decades of research has gone into an understanding of which parts of the insectbrain possess particular behaviors, but exactly how they modulate these functional conse-quences needs to be clarified. Detailed description of the brain and behavior is required todecipher the complexity of cell types, as well as their connectivity and function. Single-cell RNA-sequencing (scRNA-seq) has emerged recently as a breakthrough technologyto understand the transcriptome at cellular resolution. With scRNA-seq, it is possible touncover the cellular heterogeneity of brain cells and elucidate their specific functions andstate. In this review, we first review the basic structure of insect brains and the links toinsect behaviors mainly focusing on learning and memory. Then the scRNA applicationson insect brains are introduced by representative studies. Single-cell RNA-seq has allowedresearchers to classify cell subpopulations within different insect brain regions, pinpointsingle-cell developmental trajectories, and identify gene regulatory networks. These devel-opments empower the advances in neuroscience and shed light on the intricate problemsin understanding insect brain functions and behaviors.

关键词： behavior brain cell type insect single-cell RNA sequencing

High-resolution tsunami hazard assessment for the Guangdong-Hong Kong-Macao Greater Bay Area based on a non-hydrostatic tsunami model

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Science China Earth Sciences 2024年第7期67卷 2326-2351页

作者： Yifan ZHU Chao AN Houyun YU Wei ZHANG xiaofei CHEN Key Laboratory of Hydrodynamics(Ministry of Education) School of Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China Department of Earth and Space Sciences Southern University of Science and Technology Shenzhen 518055China

The Guangdong-Hong Kong-Macao Greater Bay Area(GBA)is threatened by potential tsunami hazards from the Littoral Fault Zone(LFZ)and the Manila subduction zone(MSZ),and may suffer huge damage because of its dense population,concentrated infrastructure,and low-lying *** tsunami studies for the GBA made simple assumptions on the mechanisms of LFZ earthquakes,and used coarse bathymetry data in tsunami simulation,which limited the prediction of detailed tsunami hazard *** this paper,we develop a parallel dispersive tsunami model PCOMCOT to efficiently simulate dispersive,nonlinear,and breaking tsunami *** also construct large-scale and high-resolution bathymetry models for the GBA by correcting and integrating various data *** rupture simulation is performed for the LFZ to obtain a more reliable earthquake source *** propose several representative earthquake scenarios for the LFZ and MSZ,and use PCOMCOT to calculate the resulting tsunami waves,currents,and inundation in the *** results indicate that if an M_(w)7.5 oblique-slip earthquake occurs in the LFZ off the Pearl River Estuary(PRE),the subsequent tsunami will primarily impact Hong Kong,causing maximum positive and negative waves of around 1 m and -2 m,respectively,along with slightly destructive currents(≥1.5 m/s).An M_(w)9.0 MSZ megathrust earthquake can lead to widespread inundation with>1 m depth on the outlying islands of Macao and in the urban areas of Hong Kong around the Victoria ***,it will also cause catastrophic tsunami currents along the narrow waterways in Hong Kong and Macao,and the spatial distribution of strong currents(≥3 m/s)shows a considerable discrepancy from the areas of serious ***,more attention should be paid to the potential impacts of tsunami currents on the GBA.

关键词： Tsunami hazards Inundation Tsunami currents Non-hydrostatic model Guangdong-Hong Kong-Macao Greater Bay Area

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Multiscale analysis-based peridynamic simulation of fracture in porous media

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Frontiers of Structural and Civil Engineering 2024年第1期18卷 1-13页

作者： Zihao YANG Shangkun SHEN xiaofei GUAN Xindang HE Junzhi CUI School of Mathematics and Statistics Northwestern Polytechnical UniversityXi’an 710072China School of Mathematical Sciences Tongji UniversityShanghai 200092China School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi’an 710072China LSEC ICMSECAcademy of Mathematics and Systems ScienceCASBeijing 100190China

The simulation of fracture in large-scale structures made of porous media remains a challenging *** techniques either assume a homogeneous model,disregarding the microstructure characteristics,or adopt a micro-mechanical model,which incurs an intractable computational cost due to its complex stochastic geometry and physical properties,as well as its nonlinear and multiscale *** this study,we propose a multiscale analysis-based dual-variable-horizon peridynamics(PD)model to efficiently simulate macroscopic structural *** influence of microstructures in porous media on macroscopic structural failure is represented by two PD parameters:the equivalent critical stretch and *** equivalent critical stretch is calculated using the microscale PD model,while the equivalent micro-modulus is obtained through the homogenization method and energy density equivalence between classical continuum mechanics and PD *** examples of porous media with various microstructures demonstrate the validity,accuracy,and efficiency of the proposed method.

关键词： porous media multiscale variable-horizon peridynamic equivalent critical stretch equivalent micro-modulus