检索结果-南通市图书馆

Few-shot incremental radar target recognition framework based on scattering-topology properties

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第8期37卷 246-260页

作者： Chenxuan LI Weigang ZHU Bakun ZHU Yonggang LI Graduate school Space Engineering UniversityBeijing 101400China Department of electronic and optical engineering Space Engineering UniversityBeijing 101400China

The continuous emergence of new targets in open scenarios leads to a substantial decrease in the performance of Inverse Synthetic Aperture Radar(ISAR)recognition ***,data scarcity further exacerbates the challenge of identifying new classes of ISAR *** this paper,a few-shot incremental target recognition framework based on Scattering-Topology Properties(STPIL)is ***,STPIL extracts scattering-topology properties of ISAR targets as recognition ***,the pseudo-incremental training strategy effectively alleviates the algorithm’s forgetting of old knowledge,and improves compatibility with new ***,a feature embedding network,with few parameters,is designed based on the graph neural *** embedding network is highly adaptable to changes in data ***,STPIL fully considers the joint distribution and marginal distribution in scattering features,and uses the Brownian distance metric module to make the scattering-topology features more *** results on both the simulation dataset and the public measured data indicate that STPIL can effectively balance new classes with old classes,and has superior performance to other advanced methods in the incremental recognition of targets.

关键词： Brownian distance metric Graph neural networks Incremental learning Inverse Synthetic Aperture Radar(ISAR) Scattering

A regularization algorithm of dynamic light scattering for estimating the particle size distribution of dual-substance mixture in water

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2024年第6期89卷 246-257页

作者： Yanghong Wang Ziqiang Meng Zipei Zhang Min Xia Li Xia Wei Li school of optical and electronic Information Huazhong University of Science and TechnologyWuhan 430074China

Dynamic light scattering(DLS)is a nondestructive,well-established technique for the size characterization of proteins,nanoparticles,polymers,and colloidal ***,current DLS techniques are only applied to particle groups of single composition due to the limitation of their inversion *** this study,we propose a particle size distribution inversion algorithm based on the Tikhnonov regularization method that can be applied to the dual-substance particle *** algorithm retrieves the particle size distributions of two substances,respectively,by taking advantage of their refractive index *** simulation results reveal that the algorithm has excellent accuracy and stability when the scattering angle is 30°.Instead of the original identity matrix,the first-order difference matrix and second-order difference matrix are used as the regular matrix when utilizing the Tikhnonov algorithm,which obviously improves the anti-interference,accuracy,and stability of the ***,the inversion of particle size distribution is carried out at a 0.01%–1%noise level,which shows that the algorithm has an available antinoise ***,experimental particle size measurements for a mixture of polystyrene beads and toner particles demonstrate that the proposed algorithm is superior to the traditional Tikhnonov algorithm in applicability and accuracy.

关键词： Dynamic light scattering Dual-substance mixture Particle sized istribution Tikhnonov regularization

Sintering of phosphor-glass composites goes ultrafast

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Materials 2024年第8期67卷 2711-2712页

作者： Xiaoyong Huang College of electronic Information and optical engineering Taiyuan University of TechnologyTaiyuan 030024China

Nowadays,with the rapid technological progress of high-quality lightings and high-end displays,high-power white light-emitting diodes(WLEDs)and high-brightness white laser diodes(WLDs)featuring with high energy density excitation,high output power and high device stability have been extensively investigated and regarded as the new-generation solid-state light sources[1–6].

关键词： diodes WLED white

维普期刊数据库

Image segmentation of exfoliated two-dimensional materials by generative adversarial network-based data augmentation

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第3期33卷 112-117页

作者：程晓昱解晨雪刘宇伦白瑞雪肖南海任琰博张喜林马惠蒋崇云 College of electronic Information and optical engineering Nankai UniversityTianjin 300350China school of Physical Science and Technology Tiangong UniversityTianjin 300387China

Mechanically cleaved two-dimensional materials are random in size and *** atomically thin flakes by human experts is inefficient and unsuitable for scalable *** learning algorithms have been adopted as an alternative,nevertheless a major challenge is a lack of sufficient actual training *** we report the generation of synthetic two-dimensional materials images using StyleGAN3 to complement the ***3Plus network is trained with the synthetic images which reduces overfitting and improves recognition accuracy to over 90%.A semi-supervisory technique for labeling images is introduced to reduce manual *** sharper edges recognized by this method facilitate material stacking with precise edge alignment,which benefits exploring novel properties of layered-material devices that crucially depend on the interlayer *** feasible and efficient method allows for the rapid and high-quality manufacturing of atomically thin materials and devices.

关键词： two-dimensional materials deep learning data augmentation generating adversarial networks

维普期刊数据库

Joint Transmit and Reflective Beamforming Design for Active IRS-Aided SWIPT Systems

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of electronics 2024年第2期33卷 536-548页

作者： Weiping SHI Qingqing WU Di WU Feng SHU Jiangzhou WANG school of electronic and optical engineering Nanjing University of Science and Technology Department of electronic engineering Shanghai Jiao Tong University school of Information and Communication engineering Hainan University Department of Automation Shanghai Jiao Tong University school of engineering University of Kent

To further improve the performance of passive intelligent reflecting surface(IRS)-assisted communication systems and mitigate the serious path loss due to “double-fading ” of IRS-assisted links, an active IRS-aided simultaneous wireless information and power transfer(SWIPT) system is investigated. This paper jointly optimizes the transmit beamforming at the base station(BS) and the phase shifts at the active IRS in order to maximize the power collected by the energy harvesting receiver under both perfect and imperfect channel state information(CSI)states, subject to the signal-to-interference-noise ratio constraint of the information decoding receiver, and the power constraints of the BS/IRS. Under perfect CSI, the alternating optimization algorithm is utilized for obtaining the transmit beamforming at the BS and the phase shifts at the active IRS. For each subproblem, we first transform nonconvex objective function and constraints into convex ones by performing a first-order Taylor expansion. Then, each subproblem is solved by using the interior point method. Given that obtaining perfect CSI is impractical, two robust beamforming designs are proposed for imperfect CSI case. Under the bounded CSI error model, we first transform the non-convex optimization problem into two semidefinite programming subproblems, and then solve each subproblem based on S-procedure and sequential rank-one constraint relaxation(SROCR) techniques. Under the stochastic CSI error model, the alternating optimization method is applied in an iterative manner based on Bernstein-type inequality and SROCR technique. Simulation results show that both robust and non-robust schemes for active IRS-assisted SWIPT systems can achieve extremely superior performance over conventional passive IRS-assisted systems under the same overall power budget.

关键词： Wireless communication Semidefinite programming Array signal processing Simulation Stochastic processes Transforms Receivers

Excitonic devices based on two-dimensional transition metal dichalcogenides van der Waals heterostructures

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Chemical Science and engineering 2024年第2期18卷 41-67页

作者： Yulun Liu Yaojie Zhu Zuowei Yan Ruixue Bai Xilin Zhang Yanbo Ren Xiaoyu Cheng Hui Ma Chongyun Jiang College of electronic Information and optical engineering Nankai UniversityTianjin 300350China school of Physical Science and Technology Tiangong UniversityTianjin 300387China

Excitonic devices are an emerging class of technology that utilizes excitons as carriers for encoding, transmitting, and storing information. Van der Waals heterostructures based on transition metal dichalcogenides often exhibit a type II band alignment, which facilitates the generation of interlayer excitons. As a bonded pair of electrons and holes in the separation layer, interlayer excitons offer the chance to investigate exciton transport due to their intrinsic out-of-plane dipole moment and extended exciton lifetime. Furthermore, interlayer excitons can potentially analyze other encoding strategies for information processing beyond the conventional utilization of spin and charge. The review provided valuable insights and recommendations for researchers studying interlayer excitonic devices within van der Waals heterostructures based on transition metal dichalcogenides. Firstly, we provide an overview of the essential attributes of transition metal dichalcogenide materials, focusing on their fundamental properties, excitonic effects, and the distinctive features exhibited by interlayer excitons in van der Waals heterostructures. Subsequently, this discourse emphasizes the recent advancements in interlayer excitonic devices founded on van der Waals heterostructures, with specific attention is given to the utilization of valley electronics for information processing, employing the valley index. In conclusion, this paper examines the potential and current challenges associated with excitonic devices.

关键词： excitonic devices van der Waals heterostructures transition metal dichalcogenides interlayer excitons valley-Hall effect optoelectronics

Black Phosphorus for Photonic Integrated Circuits

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research 2024年第2期2023卷 339-353页

作者： Mingxin Zhang Lele Yang Xiaoxuan Wu Junjia Wang National Research Center for optical Sensors/communications Integrated Networks School of Electronic Science and EngineeringSoutheast University2 SipailouNanjing 210096China

Black phosphorus gives several advantages and complementarities over other two-dimensional *** has drawn extensive interest owing to its relatively high carrier mobility,wide tunable bandgap,and in-plane anisotropy in recent *** manuscript briefly reviews the structure and physical properties of black phosphorus and targets on black phosphorus for photonic integrated *** of the applications are discussed including photodetection,optical modulation,light emission,and polarization *** recent progresses,associated challenges,and future potentials are covered.

关键词： polarization tunable phosphorus

Topological edge and corner states of valley photonic crystals with zipper-like boundary conditions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第4期33卷 480-491页

作者：沈云峰许孝芳孙铭周文佶常雅箐 school of Mechanical engineering Jiangsu UniversityZhenjiang 212000China school of optical and electronic Information Suzhou City University&Suzhou Key Laboratory of BiophotonicsSuzhou 215104China

We present a stable valley photonic crystal(VPC)unit cell with C_(3v)symmetric quasi-ring-shaped dielectric columns and realize its topological phase transition by breaking mirror *** on this unit cell structure,topological edge states(TESs)and topological corner states(TCSs)are *** obtain a new type of wave transmission mode based on photonic crystal zipper-like boundaries and apply it to a beam splitter assembled from rectangular photonic crystals(PCs).The constructed beam splitter structure is compact and possesses frequency separation *** addition,we construct a box-shaped triangular PC structures with zipper-like boundaries and discover phenomena of TCSs in the corners,comparing its corner states with those formed by other *** on this,we explore the regularities of the electric field patterns of TESs and TCSs,explain the connection between the characteristic frequencies and locality of TCSs,which helps better control photons and ensures low power consumption of the system.

关键词： valley photonic crystal topological edge states topological corner states higher-order topological insulators topological phase transition

维普期刊数据库

Blindness-free beam scanning antenna with array of array architecture: principle,design,and experiment

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第3期67卷 209-224页

作者： Jianxu SUN Yujian CHENG school of electronic Science and engineering University of electronic Science and Technology of China

This paper presents a 66–76-GHz sparsely-excited phased array antenna with the array of array(Ao A) architecture for eliminating the blindness and suppressing the grating lobe when scanning. For the array antennas printed on the thick dielectric layers with high relative permittivity, scanning blindness appears and seriously impacts the radiation performance. To address this issue, the Ao A topology is developed first. It finds that the scanning blindness appears due to the coupling of the radiating Floquet modes to the non-radiating surface wave(SW) modes. Therefore, the array is divided into two types of domino *** inner-phase distributions are introduced into the domino subarrays to break the one-to-one relationship between the Floquet mode and the SW mode. Then, the blindness inside ±60° scanning volume is eliminated by the aperiodic subarrays. Meanwhile, the aperiodic inner-phase distributions enhance the aperiodicity of the array and contribute to suppressing the grating lobe when scanning. Next, the meta-surface-based dipole with the shorted post is chosen as the unit cell for the proposed aperiodic array. Based on these methods,the array achieves the wide-scanning performance of ±60° in the E-plane and ±30° in the H-plane, without the blindness and the grating lobe. Finally, the 16×16 array is built and simulated with the dimension of32 mm × 32 mm. At the highest operating frequency, the simulated gains are 28.42, 25.17, and 24.01 d Bi when scanning to the broadside, 50° in the E-plane, and 30° in the H-plane, respectively. Compared to the ideal gain, it shows that the simulated radiation efficiency is about 84.13%, 62.08%, and 35.23% when scanning to the broadside, 50° in the E-plane, and 30° in the H-plane, respectively. The worst transmission coefficient, i.e., the worst isolation, is-11.97 d B between the central element and its two adjacent elements in the E-plane. The array prototypes are fabricated, and the experiments are carried out to ver

关键词： 6G communication systems phased array AoA aperiodic subarray wideband wide-scanning surface-wave scanning blindness grating lobe