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Broadband high-efficiency dielectric metalenses based on quasi-continuous nanostrips

Opto-Electronic Advances 2024年第5期7卷 43-51页

作者： Xiaohu Zhang Qinmiao Chen Dongliang Tang Kaifeng Liu Haimo Zhang Lintong Shi Mengyao He Yongcai Guo Shumin Xiao Key Laboratory of optoelectronic Technology and Systems of the Education Ministry of China Chongqing UniversityChongqing 400044China Ministry of Industry and Information Technology Key Lab of Micro-Nano Optoelectronic Information System Guangdong Provincial Key Laboratory of Semiconductor Optoelectronic Materials and Intelligent Photonic SystemsHarbin Institute of TechnologyShenzhen 518055China Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education&Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices School of Physics and ElectronicsHunan UniversityChangsha 410082China

Benefiting from the abrupt phase changes within subwavelength thicknesses,metasurfaces have been widely applied for lightweight and compact optical *** broadband and high-efficiency characteristics are highly attractive for the practical implementation of ***,current metasurface devices mostly adopt discrete micro/nano structures,which rarely realize both merits *** this paper,dielectric metasurfaces composed of quasi-continuous nanostrips are proposed to overcome this *** quasi-continuous nanostrips metasurface,a normal focusing metalens and a superoscillatory lens overcoming the diffraction limit are designed and experimentally *** quasi-continuous metadevices can operate in a broadband wavelength ranging from 450 nm to 1000nm and keep a high power *** average efficiency of the fabricated metalens reaches 54.24%,showing a significant improvement compared to the previously reported metalenses with the same *** proposed methodology can be easily extended to design other metadevices with the advantages of broadband and high-efficiency in practical optical systems.

关键词： broadband high-efficiency metalens sub-diffraction quasi-continuous

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SlotFusion: Object-Centric Audiovisual Feature Fusion with Slot Attention for Remote Sensing Scene Recognition

SlotFusion: Object-Centric Audiovisual Feature Fusion with S...

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International Conference on Acoustics, Speech, and Signal Processing (ICASSP)

作者： Fangzhou Han Tianyi Yu Lamei Zhang Lingyu Si Yiqi Zhang Dept. of Information Engineering Harbin Institute of Technology Harbin China National Key Laboratory of Space Integrated Information System Institute of Software Chinese Academy of Sciences Beijing China Institute of Software Chinese Academy of Sciences Beijing China

ISBN: (数字)9798350368741

ISBN: (纸本)9798350368758

Despite significant advancements in remote sensing multimodal learning, particularly in image-image feature fusion, the exploration of audio-image feature fusion remains insufficient. Given the complexity and redundancy of ground objects in remote sensing images, accurately aligning audio features with image features during the fusion process is a critical challenge. In this paper, we introduce an object-centric feature fusion method named SlotFusion. By employing a slot attention-based feature decoupling module and a slot-based audiovisual feature fusion module, we transform modality features with complex semantic information into a set of slot features corresponding to object units and use gated activation units to adaptively implement object-centric feature fusion. Experiments on the Audio Visual Aerial Scene Recognition dataset (ADVANCE) demonstrate that the proposed SlotFusion significantly improves remote sensing scene recognition performance, with a 7.04% increase in overall accuracy compared to previous methods, achieving state-of-the-art results.

关键词： Visualization Semantics Termination of employment Transforms Interference Signal processing Logic gates Robustness Speech processing Remote sensing

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Single-Photon LiDAR Depth Estimation Based on Time Series Correlation

Single-Photon LiDAR Depth Estimation Based on Time Series Co...

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Academic International Symposium on Optoelectronics and Microelectronics technology (AISOMT)

作者： Lin Ruobin Sun Jianfeng Jiang Peng Ma Le Zhou Xin Ren Zhen Ding Ji National Key Laboratory of Laser Spatial Information Harbin Institute of Technology Harbin Heilongjiang China Zhengzhou Research Institute Harbin Institute of Technology Zhengzhou Henan China National Key Laboratory of Complex System Control and Intelligent Agent Cooperation Beijing China Tianjin Jinhang Technical Physics Institute Tianjin China Beijing Aerospace Automatic Control Institute Beijing China

ISBN: (数字)9798331542283

ISBN: (纸本)9798331542290

With advancements in science and technology, photon-counting LiDAR applications are growing due to long-range measurement, high-definition imaging, and accuracy. Geiger-mode avalanche photodiodes (Gm-APD) provide single-photon sensitivity and picosecond resolution, but noise in depth estimation affects imaging accuracy. This study introduces a novel depth estimation method using time series correlation to mitigate these noise issues, improving accuracy in LiDAR imaging. Utilizing a photon-counting LiDAR system and time-correlated single photon counting (TCSPC), this study capture target echo photon flight times to maintain depth information. The proposed denoising approach incorporates multiple time series windows and Bayesian estimation to enhance depth accuracy, alongside a pruning algorithm to optimize computational efficiency. Evaluation metrics show significant improvements: RSNR improved by 4% and MAE decreased by 43 % compared to traditional methods. The findings demonstrate the robustness of this method across various scenarios, enhancing depth estimation and noise mitigation in photon-counting LiDAR technology, thereby providing practical improvements for a range of applications.

关键词： Correlation Laser radar Accuracy Filtering Depth measurement Time series analysis Noise reduction Imaging Bayes methods Photonics

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Review of DC-DC Converter Topologies Based on Impedance Network with Wide Input Voltage Range and High Gain for Fuel Cell Vehicles

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Automotive Innovation 2021年第4期4卷 351-372页

作者： Xiaogang Wu Jiulong Wang Yun Zhang Jiuyu Du Zhengxin Liu Yu Chen Institute of Electrical and Electronic Engineering Harbin University of Science and TechnologyHarbin 150080China Institute of Electrical and Information Engineering Tianjin UniversityTianjin 300072China State Key Laboratory of Automotive Safety and Energy Tsinghua UniversityBeijing 100084China

The development of fuel cell vehicles(FCVs)has a major impact on improving air quality and reducing other fossil-fuel-related ***-DC boost converters with wide input voltage ranges and high gains are essential to fuel cells and DC buses in the powertrains of FCVs,helping to improve the low voltage of fuel cells and“soft”output *** build DC-DC converters with the desired performance,their topologies have been widely investigated and *** to obtain the optimal design of wide input range and high-gain DC-DC boost converter topologies for FCVs,a review of the research status of DC-DC boost converters based on an impedance network is ***,an evaluation system for DC-DC topologies for FCVs is constructed,providing a reference for designing wide input range and high-gain boost *** evaluation system uses eight indexes to comprehensively evaluate the performance of DC-DC boost converters for *** this basis,issues about DC-DC converters for FCVs are discussed,and future research directions are *** main future research directions of DC-DC converter for FCVs include utilizing a DC-DC converter to realize online monitoring of the water content in FCs and designing buck-boost DC-DC converters suitable for high-power commercial FCVs.

关键词： Fuel cell vehicles DC-DC boost converter Evaluation systems and indexes High gain topology

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Recent Advances in Structural Optimization and Surface Modification on Current Collectors for High‑Performance Zinc Anode:Principles,Strategies,and Challenges

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Nano-Micro Letters 2023年第11期15卷 317-348页

作者： Yuxin Gong Bo Wang Huaizheng Ren Deyu Li Dianlong Wang Huakun Liu Shixue Dou MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage State Key Laboratory of Urban Water Resource and EnvironmentSchool of Chemistry and Chemical EngineeringHarbin Institute of TechnologyHarbin 150001HeilongjiangPeople’s Republic of China Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) College of ChemistryNankai UniversityTianjin 300071People’s Republic of China Institute of Energy Material Science University of Shanghai for Science and TechnologyShanghai 200093People’s Republic of China

The last several years have witnessed the prosperous development of zinc-ion batteries(ZIBs),which are considered as a promising competitor of energy storage systems thanks to their low cost and high ***,the reversibility and availability of this system are blighted by problems such as uncontrollable dendritic growth,hydrogen evolution,and corrosion passivation on anode side.A functionally and structurally well-designed anode current collectors(CCs)is believed as a viable solution for those problems,with a lack of summarization according to its working ***,this review focuses on the challenges of zinc anode and the mechanisms of modified anode CCs,which can be divided into zincophilic modification,structural design,and steering the preferred crystal facet *** possible prospects and directions on zinc anode research and design are proposed at the end to hopefully promote the practical application of ZIBs.

关键词： Zinc anodes Current collectors Surface modification Structural design Crystal facet orientation

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PI2-CMA Based Trajectory Planning Method for the Tractor-Trailer Vehicle 6

PI2-CMA Based Trajectory Planning Method for the Tractor-Tra...

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6th IEEE International Conference on Pattern Recognition and Artificial Intelligence, PRAI 2023

作者： Wang, You Wang, Zehao Wang, Jingchuan Guo, Rui Xiao, Peng Shanghai Jiao Tong University Key Laboratory of System Control and Information Processing Ministry of Education Institute of Medical Robotics and Department of Automation Shanghai200240 China State Grid Intelligence Technology CO. LTD China

ISBN: (纸本)9798350325485

The motion primitive-based state lattice trajectory planning method has been widely used in the field of trajectory planning. However, due to the limitations of the search space and resolution of motion primitives, and the lack of consideration of scenario information during offline generation of motion primitives, the tractor-Trailer vehicles can easily fall into "jackknife phenomenon"when making large pose adjustments in narrow scenarios, which brings dilemma for trajectory planning. In this paper, a trajectory planning algorithm is proposed based on a general model of tractor-Trailer vehicle, which combines global planning and local optimization. The method first generates a series of motion primitives, including forward and backward driving conditions, and then an A based global state lattice planner is used to obtain a planning result, which is imported as the initial solution into the local trajectory optimizer based on PI2-CMA (Path Integral Policy Improvement with Covariance Matrix Adaptation) algorithm and dynamic potential method. Experiments show that this method significantly improves the performance in the obstacle avoidance, "jackknife phenomenon"avoidance and curvature compared to traditional motion primitive-based state lattice planning methods. © 2023 IEEE.

关键词： Trajectories

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Multi-Layer RIS on Edge: Communication, Computation and Wireless Power Transfer

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IEEE Internet of Things Magazine 2025年第3期8卷 100-108页

作者： Chen, Shuyi Jia, Junhong Zhang, Baoqing Hui, Yingzhe Qin, Yifan Meng, Weixiao Xu, Tianheng Harbin Institute of Technology Communication Research Center China-Chile ICT Belt and Road Joint Laboratory China Beijing Institute of Electronic System Engineering China Harbin Engineering University Ministry of Education Key Lab of In-fiber Integrated Optics China Shanghai Advanced Research Institute Chinese Academy of Sciences China

The rapid expansion of Internet of Things (IoT) and its integration into various applications high-light the need for advanced communication, computation, and energy transfer techniques. However, the traditional hardware-based evolution of communication systems faces challenges due to exces-sive power consumption and prohibitive hardware cost. With the rapid advancement of reconfigu-rable intelligent surface (RIS), a new approach by parallel stacking a series of RIS, i.e., multi-lay-er RIS, has been proposed. Benefiting from the characteristics of scalability, passivity, low cost, and enhanced computation capability, multi-layer RIS is a promising technology for future massive IoT scenarios. Thus, this article proposes a multi-layer RIS-based universal paradigm at the network edge, enabling three functions, i.e., multiple-input multi-ple-output (MIMO) communication, computation, and wireless power transfer (WPT). Starting by pic-turing the possible applications of multi-layer RIS, we explore the potential signal transmission links, energy transmission links, and computation pro-cesses in IoT scenarios, showing its ability to handle on-edge IoT tasks and associated green challeng-es. Then, these three key functions are analyzed respectively in detail, showing the advantages of the proposed scheme, compared with the traditional hardware-based scheme. To facilitate the implementation of this new paradigm into reality, we list the dominant future research directions at last, such as inter-layer channel modeling, resource allocation and scheduling, channel estimation, and edge training. It is anticipated that multi-layer RIS will contribute to more energy-efficient wireless networks in the future by introducing a revolution-ary paradigm shift to an all-wave-based approach. © 2018 IEEE.

关键词： Energy transfer

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Research on Intelligent Temperature Control Method of Closed-Loop Cooling system Based on Deep Q-Network

SSRN

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SSRN 2024年

作者： Liu, Yongchao Wang, Bo Zheng, Wei Wang, Zibo Li, Tong Cheng, Jiahao Niu, Zhenfeng Ke, Zhiwu Tan, Sichao Li, Jiangkuan Gao, Puzhen Tian, Ruifeng Zhu, Qidan Heilongjiang Provincial Key Laboratory of Nuclear Power System & Equipment Harbin Engineering University Harbin150001 China Key Laboratory of Nuclear Safety and Advanced Nuclear Energy Technology Ministry of Industry and Information Technology Harbin Engineering University Harbin150001 China Science and Technology Thermal Energy and Power Laboratory Wuhan430205 China Wuhan Second Ship Design and Research Institute Wuhan430205 China College of Intelligent Systems Science and Engineering Harbin Engineering University Harbin150001 China

As one of the most important subsystem types in the nuclear power system, the closed-loop cooling system is used for the heat transfer of the system. The control quality of its operating temperature is important for the safe operation of the entire nuclear power system. This paper proposes an intelligent temperature control method based on deep reinforcement learning (DRL). First, the closed-loop cooling system simulator is built and expanded to provide an experimental platform for the implementation of DRL. Secondly, a DRL interaction system is designed based on prior knowledge such as system thermal control characteristics and temperature control targets. Finally, the improved deep Q-network (DQN) algorithm is used to train the deep neural network agent, and the optimal temperature control strategy is approached and saved through self-learning interaction. The experimental results demonstrate that the DRL controller can realize automatic control operation and has good target tracking ability and robustness. © 2024, The Authors. All rights reserved.

关键词： Reinforcement learning

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Design Method of Changing Medium Voltage Alternating-Current Cable to Direct-Current Operation

EEA - Electrotehnica, Electronica, Automatica

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EEA - Electrotehnica, Electronica, Automatica 2022年第4期70卷 54-63页

作者： Han, Xiao Liu, Xiongjun Gao, Junguo Chen, Longxiao Tang, Chendan Jiangsu Shangshang Cable Group Academy of Science and Technology Liyang213300 China Key Laboratory of Engineering Dielectrics and Its Application Ministry of Education Harbin University of Science and Technology Harbin150080 China State Grid Electric Power Research Institute Nanjing210000 China Jiangsu Shangshang Cable Group Co. Ltd. Liyang213300 China

Changing the existing medium voltage alternating current cable to transmit direct current is a feasible technical transformation scheme, which has obvious advantages in cable capacity increase and operation reliability improvement. At present, there is only one project case introduced in the alternating current to direct current conversion of medium voltage alternating current cables. Most of the studies are carried out from the perspective of theoretical analysis and design calculation. The research focuses on the constraints of alternating current to direct current conversion of different cables and the design of ampacity and voltage. This paper studies the design method of converting the existing alternating current cable to direct current, analyses some problems in the current design and the technical details that need to be further improved, and discusses the constraints of converting the medium voltage alternating current cable to direct current from the aspects of current carrying capacity design, system design and system design, insulation temperature difference and electric field inversion, voltage design, space charge accumulation threshold calculation, electrical type test, etc. On this basis, this paper puts forward a design idea of alternating current to direct current transformation of medium voltage alternating current cable based on comprehensive constraints and suitable for practical engineering transformation and makes an example calculation. Finally, it gives implementation suggestions for the electrical type test of alternating current to direct current transformation of medium voltage alternating current cable. © 2022, Editura ELECTRA. All rights reserved.

关键词： Design

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Magnetoelectric Coupling Based on Protons in Ammonium Sulfate

arXiv

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arXiv 2024年

作者： Meng, Lei He, Chen Yen, Fei State Key Laboratory on Tunable Laser Technology Ministry of Industry and Information Technology Key Laboratory of Micro-Nano Optoelectronic Information System The School of Science Harbin Institute of Technology Shenzhen China University Town Guangdong Shenzhen518055 China

Most ferroelectric crystals have their own set of unique characteristics and ammonium sulfate (NH4)2SO4 is no exception. We report on two previously unidentified features in ammonium sulfate: 1) that there are at least two successive transitions instead of one occurring at the Curie temperature TC = 223 K according to dielectric constant measurements;and 2) pronounced step-like anomalies are found in the magnetic susceptibility χ(T) exactly at TC. To explain these results, we take into account that there exists a previously unidentified linear coupling between the magnetic and electric dipole moments of the NH4+ tetrahedra due to their rapid reorientations and distorted geometry, respectively. The magnetic moments are small, 0.0016 μB for every C3 reorientation which involve three protons (H+) undergoing orbital motion. Nevertheless, short-range correlations exist in the paraelectric phase because the magnetic moments are restricted to only point along 14 possible orientations due to the symmetry and periodic nature of the potential wells. At TC, C2 reorientations (involving four protons) are no longer energetically feasible so the reduction in the degrees of freedom to 8 further enhances the effect of the magnetic interactions. This triggers long-range ordering of the orbital moments in an antiferromagnetic configuration along the ab-plane, which via Dzyaloshinskii–Moriya interactions, end up canting slightly toward the c-axis direction. Since there exists two types of inequivalent NH4+ groups that reorient at different frequencies with temperature and do not have the same degree of distortion, the emerging polar phase is ferrielectric. This previously unidentified 'magnetoprotonic' effect can be further extended toward understanding the fundamental causes of the spontaneous polarization in many other ferroelectric crystals as well as provide the missing link toward understanding the enhanced functionalities of many hydrogen-based compounds and organic-inorganic hy

关键词： Sulfur compounds

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