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IET International Radar Conference (IRC 2023)

作者： Xiangyu Ji Jingpeng Gao Geng Chen Lu Gao College of Information and Communication Engineering Harbin Engineering University Harbin People's Republic of China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing Institute of Space Long March Vehicle Beijing People's Republic of China

ISBN: (数字)9781837240982

In view of the limited generalization and poor local feature information modeling ability of vision transformer model(ViT) in hyperspectral image classification, a Spectral-Spatial Attention Fusion Transformer (SAFT) method for hyperspectral image classification is proposed in this paper. The proposed method includes two key modules: Spectral-Spatial Feature Extraction Module (SSFE) and Multi-Head Attention Fusion Transformer Module (MAFT). The SSFE module is a lightweight network. It contains a 3D convolution block and a 2D convolution block, which can efficiently obtain local feature information. Based on the proposed attention fusion structure, the MAFT module designs an improved transformer encoder. It improves the generalization ability of the model on the premise of obtaining global information. In this paper, two datasets of HyRANK are used for experiments. The experimental results show that this method is superior to other HSI classification methods.

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Characteristic Mode Design of Dual-Band Multistate Tunable Absorber Based on Programmable Flexible Metasurface

TechRxiv

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TechRxiv 2022年

作者： Li, Mengmeng Ning, Zihao Ding, Dazhi Ai, Xia Liu, Jiaqi Wang, Chao-Fu The Department of Communication Engineering Nanjing University of Science and Technology Nanjing China The National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing100076 China The Department of Electrical and Computer Engineering National University of Singapore Singapore

Theory of characteristic modes (TCM) is applied to the design of a programmable flexible metasurface (PFMS) to achieve its multistate tunable microwave absorption. The designed metasurface consists of two layers. The first layer is a very thin polyimide (PI), on which unit cells consisting of two trapezoidal patches symmetrical along the central bias microstrip are printed. The second layer is grounded polyvinyl chloride (PVC) substrate to maintain the flexibility of the designed structure. The TCM is used to analyze and understand the modal behavior of the unit cell, which provides clear underlying electromagnetic (EM) physics to guide us how to load positive-intrinsic-negative (PIN) diode as a tunable resistance to achieve variable absorption states. The designed PFMS absorber have been fabricated and experimentally verified on the flat and cylindrical foams, respectively. Good agreements can be found for both planar and cylindrical metasurface structures between full-wave simulations and measurements. Less than -10 dB reflectivity is achieved from 3.6 to 10.7 GHz (99%). The mimicry of time-varying scattering cross section (SCS) is further realized through real-time coding PFMS absorber, which can be precisely tuned from -30 dB to 0 dB with a step of 1.5 dB at 5.5 GHz and 10.4 GHz, respectively. © 2022, CC BY.

关键词： Polyvinyl chlorides

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Research on Heterogeneous Parallel Algorithms for Radar Signal Processing in OpenCL Platform

Research on Heterogeneous Parallel Algorithms for Radar Sign...

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International Applied Computational Electromagnetics Society Symposium (ACES)

作者： Yingfei Wang Xiaoqin Xue Wei Wang Department of Computer Science Xi’an Polytechnic University Xi’an China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing Institute of Space Long March Vehicle Beijing China

An efficient radar signal processing parallel algorithm for Open Computing Language (OpenCL) is presented in this paper, which reveals a rational allocation schema of tasks between the central processing unit (CPU) and the graphics processing unit (GPU). The powerful parallel processing ability of GPU is used to replace the traditional serial processing method by the way of pipeline acceleration and algorithm parallel acceleration, and the real-time performance of the proposed algorithm is improved by the design idea of intra-module parallelism and inter-module flow processing. The algorithm is applied to CPU-GPU heterogeneous computing platform and has a good portability. The effectiveness and real-time performance of the algorithm are verified through simulation data.

关键词： Signal processing algorithms Graphics processing units Radar signal processing Real-time systems Heterogeneous networks Central Processing Unit Resource management

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Widely tunable single-photon source with high spectral-purity from telecom wavelength to mid-infrared wavelength based on MgO:PPLN

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Chinese physics B 2021年第10期30卷 108-112页

作者： Chang-Wei Sun Yu Sun Jia-Chen Duan Guang-Tai Xue Yi-Chen Liu Liang-Liang Lu Qun-Yong Zhang Yan-Xiao Gong Ping Xu Shi-Ning Zhu National Laboratory of Solid State Microstructures and School of Physics Nanjing UniversityNanjing 210093China Key Laboratory of Optoelectronic Technology of Jiangsu Province School of Physical Science and TechnologyNanjing Normal UniversityNanjing 210023China Faculty of Mathematics and Physics Huaiyin Institute of TechnologyHuaian 223003China

By utilizing the extended phase-matching(EPM)method,we investigate the generation of single photons with high spectral-purity in a magnesium-doped periodically-poled lithium niobate(MgO:PPLN)crystal via the spontaneous parametric down-conversion(SPDC)*** adjusting the temperature and pump wavelength,the wavelength of the single photons can be tuned from telecom to mid-infrared(MIR)wavelengths,for which the spectral-purity can be above 0.95 with high transmission *** experiments,we engineer a MgO:PPLN with poling period of 20.35µm which emits the EPM photon pair centered at 1496.6 nm and 1644.0 nm and carry out the joint spectral intensity(JSI)and Glauber’s second-order self-correlation measurements to characterize the spectral *** results are in good agreement with the numerical *** work may provide a valuable approach for the generation of spectrally pure single photons at a wide range of wavelengths which is competent for various photonic quantum technologies.

关键词： single photons quantum technologies periodically-poled lithium niobate

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Toward a Learnable Climate Model in the Artificial Intelligence Era

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Advances in Atmospheric sciences 2024年第7期41卷 1281-1288页

作者： Gang HUANG Ya WANG Yoo-Geun HAM Bin MU Weichen TAO Chaoyang XIE State key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Laboratory for Regional Oceanography and Numerical Modeling Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237China University of Chinese Academy of Sciences Beijing 100049China Department of Environmental Planning Graduate School of Environmental StudiesSeoul National UniversitySeoul 08826South Korea School of Software Engineering Tongji UniversityShanghai 200092China

Artificial intelligence(AI)models have significantly impacted various areas of the atmospheric sciences,reshaping our approach to climate-related *** this AI-driven transformation,the foundational role of physics in climate science has occasionally been *** perspective suggests that the future of climate modeling involves a synergistic partnership between AI and physics,rather than an“either/or”*** controversies around current physical inconsistencies in large AI models,we stress the critical need for detailed dynamic diagnostics and physical ***,we provide illustrative examples to guide future assessments and constraints for AI *** AI integration with numerical models,we argue that offline AI parameterization schemes may fall short of achieving global optimality,emphasizing the importance of constructing online ***,we highlight the significance of fostering a community culture and propose the OCR(Open,Comparable,Reproducible)*** a better community culture and a deep integration of physics and AI,we contend that developing a learnable climate model,balancing AI and physics,is an achievable goal.

关键词： artificial intelligence deep learning learnable climate model

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Cone-Shaped Space Target Inertia Characteristics Identification by Deep Learning with Compressed Dataset

TechRxiv

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TechRxiv 2022年

作者： Li, Mengmeng Wang, Shaoran Yang, Tian Ai, Xia Liu, Jiaqi Andriulli, Francesco P. Ding, Dazhi Department of Communication Engineering Nanjing University of Science and Technology Nanjing China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing100076 China Politecnico di Torino of Turin Turin Italy

An effective method for identifying inertia characteristics of cone-shaped space target based on deep learning is proposed. The inertia ratio is determined by the time-varying scattering fields from the cone-shaped targets. The multistatic method is introduced to reduce the evaluation time of time-varying scattering fields. The micro-Doppler spectrogram (MDS) dataset is constructed by time-frequency analysis with numerical simulation method, point scattering model, and experimental tests. The compressed dataset is further achieved by truncated singular value decomposition (SVD). Finally, the micro-motion parameter identification model is constructed to identify the inertia ratio for the cone-shaped space target. The interaction loss function and the feed-forward denoising convolutional neural networks (DnCNNs) are employed to improve the identification accuracy. Parameters identification of the precession frequency, precession angle, spin frequency, and inertia ratio with both simulation and experiment datasets demonstrate the validity of the proposed method. © 2022, CC BY.

关键词： Singular value decomposition

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The Warm Arctic-Cold Eurasia Pattern and Its key Region in Winter in CMIP6 Model Simulations

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Advances in Atmospheric sciences 2023年第12期40卷 2138-2153,I0002-I0006页

作者： Liang ZHAO Yunwen LIU Yihui DING Qingquan LI Wei DONG Xinyong SHEN Wei CHENG Haoxin YAO Ziniu XIAO State Key Laboratory of Numerical Modeling for Atmosphere Sciences and Geophysical Fluid Dynamics(LASG) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological DisastersNanjing University of Information Science and TechnologyNanjing 210044China Neijiang Meteorological Bureau Neijiang 641000China China Meteorological Administration National Climate CenterBeijing 100081China Key Laboratory of Geoscience Big Data and Deep Resource of Zhejiang Province School of Earth SciencesZhejiang UniversityHangzhou 310058China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519082China Beijing Institute of the Applied Meteorology Beijing 100029China

An enhanced Warm Arctic-Cold Eurasia(WACE)pattern has been a notable feature in recent winters of the Northern ***,divergent results between model and observational studies of the WACE still *** study evaluates the performance of 39 climate models participating in the Coupled Model Intercomparison Project Phase 6(CMIP6)in simulating the WACE pattern in winter of 1980-2014 and explores the key factors causing the differences in the simulation capability among the *** results show that the multimodel ensemble(MME)can better simulate the spatial distribution of the WACE pattern than most single *** that can/cannot simulate both the climatology and the standard deviation of the Eurasian winter surface air temperature well,especially the latter,usually can/cannot simulate the WACE pattern *** mainly results from the different abilities of the models to simulate the range and intensity of the warm anomaly in the Barents Sea-Kara seas(BKS)*** analysis shows that a good performance of the models in the BKS area is usually related to their ability to simulate location and persistence of Ural blocking(UB),which can transport heat to the BKS region,causing the warm Arctic,and strengthen the westerly trough downstream,cooling central ***,simulation of UB is key and significantly affects the model’s performance in simulating the WACE.

关键词： warm Arctic-cold Eurasia pattern Arctic amplification CMIP6 simulation evaluation extreme climate blocking highs

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Electroextraction of neodymium from LiCl-KCl melt using binary liquid Ga-Al cathode

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Journal of Rare Earths 2023年第8期41卷 1250-1257,I0005页

作者： Li Ding Xuepeng Wang Yongde Yan Valeri Smolenski Wenda Xu Alena Novoselova Yun Xue Fuqiu Ma Xingmei Zhang Key Laboratory of Superlight Materials and Surface Technology Ministry of EducationCollege of Materials Science and Chemical EngineeringHarbin Engineering UniversityHarbin 150001China Yantai Research Institute of Harbin Engineering University Yantai 264006China Institute of High-Temperature Electrochemistry UB RAS Ekaterinburg 620990Russia Department of Rare Metals and Nanomaterials Institute of Physics and TechnologyUral Federal UniversityEkaterinburg 620990Russia Yantai Standard Metrology Inspection&Test Center National Steam Flowrate Measurement StationYantai 264000China

The electrochemical behaviour of Nd(Ⅲ)ion was investigated on inert W,active Ga and Ga-AI *** is established that the reduction of Nd(Ⅲ)ion on the inert electrode is a consecutive two-step process while that on the active electrodes is a one-step *** apparent standard potential of the Nd(Ⅲ)/Nd redox couple at different temperatures was determined by open-circuit chronopotentiometry and semi-differential method,and the relationship between temperature and apparent standard potential was further *** thermodynamic properties of Nd in Ga and Ga-Al electrodes such as activity coefficient and activity were evaluated via intermittent coulomb titration and temperature dependence test,and the effect of temperature on activity coefficient was ***,Nd was successfully extracted in form of alloy from molten salt by galvanostatic electrolysis,in which the current efficiency of91.7%for the electroextraction indicates that the binary liquid Ga-Al electrode has favorable performance.

关键词： Rareearths Electroextraction Spent nuclear fuel Pyrochemical processing Lanthanides Binary liquid cathode

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A Jamming Decision-Making Method Based on Next State Prediction SAC

A Jamming Decision-Making Method Based on Next State Predict...

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IEEE International Conference on Electronic Information and Communication technology (ICEICT)

作者： Geng Chen Jingpeng Gao Tianran Zhang Zhiye Jiang Chen Shen College of Information and Communication Engineering Harbin Engineering University Haibin China Beijing Institute of Electronic System Engineering Beijing China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing Institute of Space Long March Vehicle Beijing China

In light of the growing complexity of the electromagnetic environment, traditional jamming decision-making methods have become less effective due to poor generalization and inefficient jamming performance. This paper proposes a jamming decision-making method based on next state prediction SAC (Soft Actor-Critic) to address this issue. Firstly, we design the state, action, and reward elements under electronic warfare scenarios. Secondly, a next state prediction critic network is proposed to accurately estimate the value function by modeling the environment dynamics and extracting richer representational information. Finally, a negative activation ReLU is introduced to improve the utilization ratio of network parameters. Simulation results show that the proposed method achieves a 98.4% success rate at a distance of 90 km from the radar and a 70.0% success rate at 30 km. Therefore, this method exhibits good adaptability and jamming performance in the field of jamming decision-making.

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Progress and prospective of electromagnetic periodic structures 4

Progress and prospective of electromagnetic periodic structu...

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4th International Applied Computational Electromagnetics Society Symposium in China, ACES-China 2021

作者： Zhang, Shengjun Mu, Lei Shao, Chunshou Ai, Xia Wang, Weidong Chai, Song Cui, Yichun Liu, Shengdong Sun, Cuiyun Zhou, Nan Xie, Lei Li, Chunyu Jiao, Luting Wang, Yue Qi, Zhaohui Wang, Minghao Yong, Zhengyu Sun, Yuan Kong, Dewang National Key Laboratory of Science Technology on Test Physics and Numerical Mathematics Beijing China The Star of Aerospace Innovation Research Institute in Changsha Hunan Changsha China Beijing Institute of Space Long March Vehicles Beijing China Institute of Survival Technology Effectiveness Evaluation of Flying Vehicle Beijing China National Key Laboratory of Science Technology on Electromagnetic Scattering Beijing China

ISBN: (纸本)9781733509619

Periodic structures have attracted interests of researches for decades, and they were discovered more and more useful properties, and have been applied to many fields. Furthermore, more and more novel concept and phenomena based on periodic structures were proposed and found, such as tunable electromagnetic properties of some structures. In this paper, recent progress on two of the periodic structures, i.e., FSS and metamaterials and their variations, were revie, and the physical nature of these structures analog to materials were also suggested. © 2021 Applied Computational Electromagnetics Society (ACES).

关键词： Periodic structures

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