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Nonlocal inverse design of an ultrasonic lens for underwater manipulation of orbital angular momentum

Physical Review Applied 2024年第2期22卷 024070页

作者： Chuanxin Zhang Fei Dai Xue Jiang Dean Ta Department of Biomedical Engineering School of Information Science and Technology State Key Laboratory of Integrated Chips and System

Acoustic orbital angular momentum (OAM) beams hold potential for underwater communications, particle manipulation, and biomedical applications. However, adapting air-based OAM technologies to the underwater environment presents unique challenges. In the underwater environment, the medium cannot be considered acoustically soft, and commonly used ultrasound frequencies have shorter wavelengths compared with air, necessitating new design approaches. Conventional underwater ultrasonic lens design methods often rely on simplified models that neglect nonlocal interactions and diffraction within the structure, therefore leading to suboptimal performance. We introduce a novel nonlocal inverse design method by integrating the full-wave models with the nondominated sorting genetic algorithm II (NSGA-II). This approach diverges from conventional phase-based design by optimizing the physical structure of the lens to account for nonlocal interactions within the material. We experimentally demonstrate the performance when generating high-purity OAM beams underwater. Our experimental results show that this method can generate high-purity OAM beams underwater, achieving over 90% purity for the OAM beams of topological charges from m = 1 to m = 4. This is a significant improvement compared with traditional methods, which typically reach 70–89% purity. These findings highlight the practical applicability of our method for nonlocally designing the ultrasonic lens, paving the way for advancements in beam performance for various applications.

关键词： Acoustic wave phenomena Inverse problems Ultrasonics Underwater acoustics Acoustic metamaterials Lenses Angular momentum Ultrasound techniques

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Large-area ultracompact pixelated aluminumwire-grid-based metamaterials for Vis-NIR full-Stokes polarization imaging

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Photonics Research 2023年第11期11卷 1975-1986页

作者： YUANYI FAN JINKUI CHU RAN ZHANG CHUANLONG GUAN JIANYING LIU State Key Laboratory of High-performance Precision Manufacturing Dalian University of TechnologyDalian 116024China Key Laboratory for Micro/Nano Technology and System of Liaoning Province Dalian University of TechnologyDalian 116024China

The study of pixelated metamaterials that integrate both the functions of linear and circular polarization filters is rapidly growing due to the need for full-Stokes polarization imaging. However, there is a lack of large-area, ultracompact pixelated full-Stokes metamaterials with excellent performance, especially circular polarization filters with a high extinction ratio, a broad operating bandwidth, and a low-cost, high-quality, efficient manufacturing process, which limits the practical applications of pixelated full-Stokes metamaterials. In this study, we propose a universal design and fabrication scheme for large-area, ultracompact pixelated aluminum wire-grid-based metamaterials used in Vis-NIR full-Stokes polarization imaging. The aluminum wire-grid was designed as a linear polarization filter with an average linear polarization extinction ratio of 36,000 and a circular polarization filter with an average circular polarization extinction ratio of 110 in Vis-NIR. A large-area, ultracompact 320 × 320pixelated aluminum wire-grid-based full-Stokes metamaterial was fabricated using nanoimprint lithography and nano transfer printing with the advantages of low cost and high efficiency. This metamaterial was used to achieve full-Stokes polarization imaging with errors within 8.77%, 12.58%, 14.04%, and 25.96% for Stokes parameters S_(0), S_(1), S_(2), and S_(3), respectively. The inversion errors of the compensated Stokes parameters can be reduced to0.21%, 0.21%, 0.42%, and 1.96%, respectively.

关键词： polarization Stokes lithography

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Prophylactic effects of sialylated glycopeptides from edible bird’s nest on neuroinflammation in lipopolysaccharide-treated mice via the gut-brain axis

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Food Science and Human Wellness 2024年

作者： Xiang-Rong Cheng Chen-Xi Zhang Xiao-Yi Zhao Qiu-Shi Li Yu Song Lan Zhang Jia-Hui Ma Yu-Yao Chen Man Yuan Dong-Liang Wang School of Food Science and Technology， Jiangnan University State Key Laboratory of Food Science and Resources， Jiangnan University Central Nervous System Drug Key Laboratory of Sichuan Province Luzhou Hebei Edible Bird's Nest Fresh Stew Technology Innovation Center

Edible bird’s nest (EBN)， abundant in sialic acid (SA) has been recognized as a natural substance beneficial to brain development and cognitive ability. In order to investigate active component of EBN， sialylated glycopeptides (SCP) were extracted from EBN by 60% ethanol after trypsin hydrolysis and its effects on central nervous system was evaluated in lipopolysaccharide (LPS)-induced neuroinflammation mice. EBN， SCP， and SA pretreatment and intervention reduced IL-1β， TNF-α， and IL-6 levels in hippocampus and cortex， meanwhile inhibited the activation of microglia， astrogliosis and neuron apoptosis， which were consistent with the learning and memory improvement and anti-depression effects in behavioral tests. The counts of leukocytes， neutrophils and monocytes， as well as IL-1β， TNF-α， and IL-6 levels in peripheral circulation were significantly reduced by SCP. Results of plasma metabolomics suggested SCP up-regulated energy metabolism， promoted the recovery of primary and secondary bile acid metabolism and indole metabolism， where microbiota may involve. 16S rDNA sequencing of colonic contents showed EBN， SCP and SA repaired dysbacteriosis in LPS-treated mice by significantly up-regulating the anti-inflammatory Muribaculaceae and inhibiting pro-inflammatory related Desulfovibrio and Candidatus＿Saccharimonas. In addition， both EBN and SCP could significantly enrich ***， while SA could specifically enrich Prevotellaceae＿UCG＿001. The gut-brain axis was preliminarily established， and SCP may have the potential to be a functional factor for neuroprotection applied in EBN industry.

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Impact of Atmospheric Transmittance and NLTE Correction on Simulation of High Spectral Infrared Atmospheric Sounder onboard FY-3E

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Journal of Meteorological Research 2024年第2期38卷 225-234页

作者： Chenggege FANG Peiming DONG Yang HAN Wanlin KAN Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological AdministrationNanjing University of Information Science&TechnologyNanjing 210044 Donghai Laboratory Zhoushan 316021 State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesChina Meteorological AdministrationBeijing 100081 CMA Earth System Modeling and Prediction Centre China Meteorological Administration(CMA)Beijing 100081 Key Laboratory of Transportation Meteorology of China Meteorological Administration Nanjing Joint Institute for Atmospheric SciencesNanjing 210041

With the launch of the first civilian early-morning orbit satellite Fengyun-3E(FY-3E),higher demands are placed on the accuracy of radiative transfer simulations for hyperspectral infrared ***,several key issues are investigated in the ***,the accuracy of the fast atmospheric transmittance model implemented in the Advanced Research and Modeling system(ARMS)has been evaluated with both the line-by-line radiative transfer model(LBLRTM)and the actual satellite *** results indicate that the biases are generally less than 0.25 K when compared to the LBLRTM,while below 1.0 K for the majority of the channels when compared to the ***,during both comparisons,significant biases are observed in certain *** accuracy of Hyperspectral Infrared Atmospheric Sounder-II(HIRAS-II)onboard FY-3E is comparable to,and even superior to that of the Cross-track Infrared Sounder(CrIS)onboard ***,apodization is a crucial step in the processing of hyperspectral data in that the apodization function is utilized as the instrument channel spectral response function to produce the satellite channel-averaged *** further explore the difference between the apodized and unapodized simulations,Sinc function is adopted in the fast transmittance *** is found that the use of Sinc function can make the simulations fit the original satellite observations *** simulating with apodized observations,the use of Sinc function exhibits larger deviations compared to the Hamming ***,a correction module is applied to minimize the impact of Non-Local Thermodynamic Equilibrium(NLTE)in the shortwave infrared *** is verified that the implementation of the NLTE correction model leads to a significant reduction in the bias between the simulation and observation for this band.

关键词： high spectral infrared sounding atmospheric transmittance apodization Non-Local Thermodynamic Equilibrium Fengyun-3E(FY-3E)

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Wind and wave prediction based on multi-task learning 34th

Wind and wave prediction based on multi-task learning

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34th International Ocean and Polar Engineering Conference, ISOPE 2024

作者： Fu, Zhu Chen, Li Chen, Weimin State Key Laboratory of Ocean Engineering Shanghai Jiao Tong University Shanghai China Key Laboratory of Marine Intelligent Equipment and System Ministry of Education Shanghai Jiao Tong University Shanghai China State Key Laboratory of Maritime Technology and Safety Shanghai Ship and Shipping Research Institute Co. Ltd Shanghai China

ISBN: (纸本)9781880653784

Accurate prediction of amplitude and direction of wind and wave is important for ocean and coastal engineering, such as ship weather routing and offshore wind farm maintenance. Traditional wind prediction and wave prediction are considered as two independent tasks in their respective fields. However, they are two related tasks, and separate prediction would result in redundant training and high computation cost. In order to solve this problem, a multi-task learning (MTL) model is proposed for wind and wave simultaneous prediction in this paper. To balance the individual loss functions for different tasks, a dynamic weight adjustment method is utilized to attain the optimal multi-task loss function weight. Finally, the proposed model is verified at a coastal location in the North Atlantic Ocean. The results show that compared with single-task learning (STL) model, the computation cost of MTL decreases by 52.9%, the storage size of MTL model decreases by 31.7%, and the MTL model can achieve the same predictive performance. © 2024 by the International Society of Offshore and Polar Engineers (ISOPE).

关键词： Learning systems

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Lifetime Estimation of HD-GITs based on Drain Leakage Current 10

Lifetime Estimation of HD-GITs based on Drain Leakage Curren...

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10th IEEE International Power Electronics and Motion Control Conference, IPEMC 2024 ECCE Asia

作者： Huang, Xu Sun, Pengju He, Zhiyuan Li, Kaiwei Li, Qiang Chen, Lan Chen, Jian Chongqing University State Key Laboratory of Power Transmission Equipment and System Security and New Technology China Guangdong University of Technology School of Integrated Circuits China Southwest Jiaotong University China

ISBN: (纸本)9798350351330

The GaN device is a high-performance alternative to Si devices in the market. However, concerns have been raised regarding their reliability. This paper characterized their reliability by conducting power cycling test (PCT). The test results reveal that the drain leakage current increases as the device degrades. This observation suggests that the drain leakage current could serve as a potential precursor for estimating the device's lifetime. To verify this, device failure is defined as the leakage current exceeding 5 times the initial. Subsequently, the experimental data were analyzed, revealing that the lifetime distribution follows a Weibull distribution. This indicates that the drain leakage current could serve as a precursor for evaluating the lifetime of GaN devices. Furthermore, by utilizing the Arrhenius relationship, the lifetime of GaN devices under various conditions can be estimated. This discovery presents a novel approach for predicting failure and modeling the lifetime of GaN devices. © 2024 IEEE.

关键词： Reliability

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A Regional Necessity Based Multi-agent Target Search Strategy for Post-earthquake Rescue 41

A Regional Necessity Based Multi-agent Target Search Strateg...

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第41届中国控制会议

作者： Xi Luo School of Automation Beijing Institute of Technology State Key Laboratory of Intelligent Control and Decision of Complex System

ISBN: (数字)9789887581536

ISBN: (纸本)9781665482561

The damage caused by the earthquake is *** the purpose of post-earthquake rescue is to reduce *** it is necessary to improve the efficiency of rescue as much as *** paper focuses on multi-agent cooperative target search in the post-earthquake rescue and how to exploit the prior information of post-disaster building to improve the searching efficiency.A regional necessity based searching strategy is proposed which utilizes pre-disaster building information and adapts to dynamic ***,the target probability map is estimated according to the distribution information of pre-disaster ***,the regional necessity map is constructed by integrating the target probability map and the perception of the environment during the search ***,the search strategy is proposed based on the regional necessity map and the particle swarm optimization *** the gradient direction of regional necessity and local optimal velocity,the agent dynamically selects the search *** comparing with other search strategies in simulation experiments,the proposed strategy could shorten the searching time and improve the searching efficiency in the small and medium-scale task ***,the search strategy can adapt to the post-earthquake dynamic environment,which is confirmed by dynamic experiments.

关键词： multi-agent cooperative target search post-earthquake rescue regional necessity particle swarm optimization

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A Defense Planning Model for a Power system Against Coordinated Cyber-physical Attack

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Protection and Control of Modern Power systems 2024年第5期9卷 84-95页

作者： Peiyun Li Jian Fu Kaigui Xie Bo Hu Yu Wang Changzheng Shao Yue Sun Wei Huang State Key Laboratory of Power Transmission Equipment&System Security and New Technology Chongqing UniversityChongqing 400044China State Grid Chengdu Power Supply Com-pany State Grid Sichuan Electric Power Co.Ltd.Chengdu 610041China China Yangtze Power Co. LtdYichang 443002China

This paper proposes a tri-level defense planning model to defend a power system against a coor-dinated cyber-physical attack(CCPA).The defense plan considers not only the standalone physical attack or the cyber attack,but also coordinated *** defense strategy adopts coordinated generation and transmission expansion planning to defend against the *** the process of modeling,the upper-level plan represents the perspective of the planner,aiming to minimize the critical load shedding of the planning system after the *** load resources available to planners are extended to flex-ible loads and critical *** middle-level plan is from the viewpoint of the attacker,and aims at generating an optimal CCPA scheme in the light of the planning strategy determined by the upper-level plan to maximize the load shedding caused by the *** optimal operational behavior of the operator is described by the lower-level plan,which minimizes the load shedding by defending against the *** tri-level model is analyzed by the column and constraint generation algorithm,which decomposes the defense model into a master problem and *** studies on a modified IEEE RTS-79 system are performed to demonstrate the economic effi-ciency of the proposed model.

关键词： Coordinated cyber-physical attack flexible load column-and-constraint generation defense planning robust optimization.

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Introduction of high-speed data acquisition system scheme based on FPGA 3

Introduction of high-speed data acquisition system scheme ba...

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3rd International Conference on Electronic Information Engineering and Data Processing, EIEDP 2024

作者： Lin, Yinghui Xu, Zhijing Sun, Jun Chen, Ren College of Information Engineering Shanghai Maritime University Shanghai China Shanghai Institute of Technical Physics State Key Laboratory of Infrared Physics Key Laboratory of Infrared System Detection and Imaging Technology Chinese Academy of Sciences Shanghai China

ISBN: (纸本)9781510680531

Signal acquisition system is widely used in various fields of reality, due to the data acquisition rate and processor performance enhancement as well as the development of sensor arrays and other technologies, the data acquisition system acquisition and transmission of the signal is exponential growth, in order to solve the high-speed signal acquisition process of the large amount of data, real-time, transmission rate and other issues, the study of high-speed acquisition of signals as well as the transmission program has an important practical significance. FPGA is very suitable to be applied in high-speed signal acquisition system because of its characteristics. In this paper, we firstly introduce the composition of a typical high-speed signal acquisition system based on FPGA, and then briefly introduce the function and development process of each module of the system and introduce the mainstream programs used in several key modules. In engineering applications, different programs should be used in different modules in conjunction with the actual. © 2024 SPIE.

关键词： Field programmable gate arrays (FPGA)

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Safety criteria based on barrier function under the framework of boundedness for some dynamic systems

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Science China(Information Sciences) 2022年第2期65卷 75-88页

作者： Zheren ZHU Yi CHAI Zhimin YANG Chenghong HUANG State Key Laboratory of Power Transmission Equipment and System Security and New Technology Chongqing University School of Automation Chongqing University Chongqing High-Tech-Zone Feima Innovation Research Institute

Barrier functions have been reported to be useful in quantifying the safety of some dynamic systems. Usually, when using the barrier functions, we try to transform safety analysis issues of dynamic systems into a class of reachability issues from a safe set to an unsafe set. This article presents a novel sufficient safety criterion for some dynamic systems. The proposed criterion is based on the barrier function and works as long as the upper bound of the barrier function is kept non-positive. Further, we present a mathematical description of fault safety for some dynamic system that experienced a fault at a certain time and propose a corresponding fault safety criterion for the aforementioned system.

关键词： safety criteria barrier function fault safety multi-hypersphere method dynamic system

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