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Chinese Journal of Aeronautics 2025年第4期 290-308页

作者： Lin LU Haiyang LI Tianshan DONG Wanmeng ZHOU College of Aerospace Science and Technology National University of Defense Technology Hunan Key Laboratory of Intelligent Planning and Simulation for Aerospace Missions Beijing Institute of Spacecraft System Engineering China Astronaut Research and Training Center

Aimed at the demand of contingency return at any time during the near-moon phase in the manned lunar landing missions,a fast calculation method for three-impulse contingency return trajectories is ***,a three-impulse contingency return trajectory scheme is presented by combining the Lambert transfer and maneuver at the special ***,a calculation model of three-impulse contingency return trajectories is ***,fast calculation methods are proposed by adopting the high-order Taylor expansion of differential algebra in the twobody trajectory dynamics model and perturbed trajectory dynamics ***,the performance of the proposed methods is verified by numerical *** results indicate that the fast calculation method of two-body trajectory has higher calculation efficiency compared to the semi-analytical calculation method under a certain accuracy *** to its high efficiency,the characteristics of the three-impulse contingency return trajectories under different contingency scenarios are further analyzed *** findings can be used for the design of contingency return trajectories in future manned lunar landing missions.

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Néel-type optical skyrmions inherited from evanescent electromagnetic fields with rotational symmetry

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arXiv 2023年

作者： Tian, Bo Jiang, Jingyao Xu, Ningsheng Zheng, Zebo Wang, Ximiao Liu, Shaojing Huang, Wuchao Jiang, Tian Chen, Huanjun Deng, Shaozhi State Key Laboratory of Optoelectronic Materials and Technologies Guangdong Province Key Laboratory of Display Material and Technology School of Electronics and Information Technology Sun Yat-sen University Guangzhou510275 China The Frontier Institute of Chip and System Fudan University Shanghai200433 China Institute for Quantum Information Science and Technology College of Science National University of Defense Technology Changsha410073 China

Optical skyrmions, the optical analogue of topological configurations formed by three-dimensional vector fields covering the whole 4π solid angle but confined in a two-dimensional (2D) domain, have recently attracted growing interest due to their potential applications in high-density data transfer, storage, and processing. While the optical skyrmions have been successfully demonstrated using different field vectors in both of free-space propagating and near-field evanescent electromagnetic fields, the study on generation and control of the optical skyrmions, and their general correlation with the electromagnetic (EM) fields, are still in infancy. Here, we theoretically propose that an evanescent transverse-magnetic-polarized (TM-polarized) EM fields with rotational symmetry are actually Néel-type optical skyrmions of the electric field vectors. Such optical skyrmions maintain the rotation symmetry that are independent on the operation frequency and medium. Our proposal was verified by numerical simulations and real-space nano-imaging experiments performed on a graphene monolayer. Such a discovery can therefore not only further our understanding on the formation mechanisms of EM topological textures, but also provide a guideline for facile construction of EM skyrmions that may impact future information technologies. Copyright © 2023, The Authors. All rights reserved.

关键词： Digital storage

A Multi-Point Two-Hop Neighbor Relay Based OLSR Routing Protocol Design Method for Self-organized Multi-agent Communication*

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A Multi-Point Two-Hop Neighbor Relay Based OLSR Routing Prot...

Control Conference (ANZCC), Australian and New Zealand

作者： Zhenlei Wang Chunfeng Li Xiongjun Wu The 54th Research Institute of China Electronics Technology Group Corporation (CETC54) Hebei Province China The 802 Institute of Shanghai Academy of Space Flight Technology The Eighth Academy of China Aerospace Science and Technology Corporation National Defense Key Laboratory of Science and Technology on Electromagnetic Scattering Shanghai Department of Automation Key Laboratory of System Control and Information Processing Ministry of Education of China Shanghai Jiao Tong University Shanghai China

The OLSR routing protocol is a proactive Linkstate routing protocol in Ad hoc networks. It uses MPR nodes to spread TC messages across the network, reducing the flooding of protocol control messages in the network. However, all MPR nodes used to propagate a TC message in the whole network are not optimal, and there are a lot of redundancy, which results in unnecessary forwarding of TC messages and increases the overhead of control protocol. To overcome this limitation, the concepts of multi-point one hop neighbor relay (MPOHNR) and multi-point two hop neighbor relay (MPTHNR) are proposed, and the node selection algorithms of MPOHNR and MPTHNR are given. By using MPOHNR and MPTHNR to forward TC messages alternately, the number of forwarding nodes is reduced, the control protocol overhead is reduced, the effective bandwidth of the link is greatly increased, and the end-to-end average delay is reduced. Numerical simulations by using the EXATA software verifies that, the improved OLSR routing protocol is a potential design method for optimizing OLSR routing protocol.

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A Symmetric Multilayer GeSe/GeSeSbTe Ovonic Threshold Switching Selector with Improved Endurance and Stability

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A Symmetric Multilayer GeSe/GeSeSbTe Ovonic Threshold Switch...

2021 IEEE International Conference on Integrated Circuits, Technologies and Applications, ICTA 2021

作者： Zhang, Shiqing Song, Bing Jia, Shujing Cao, Rongrong Liu, Sen Xu, Hui Li, Qingjiang National University of Defense Technology College of Electronic Science and Engineering Changsha410073 China Chinese Academy of Sciences Key Laboratory of Functional Materials for Informatics Shanghai Institute of Micro-System and Information Technology Shanghai200050 China

ISBN: (纸本)9781665417471

Ovonic threshold switching (OTS) selector is becoming the most suitable candidate for selector devices in memristor crossbar array, owing to its high selectivity and fast response time. However, device endurance and variance are persistent tricky problems for application. In this article, a novel symmetric multilayer OTS selector based on simple GeSe and SbTe-doped GeSe was investigated. The results showed improving selector performed extraordinary endurance up to 1010 and the fluctuation of threshold voltage is 1.5 %. These developments pave the way towards tuning a new class of OTS materials engineering, ensuring improvement of electrical performances. © 2021 IEEE.

关键词： Selenium compounds

Dispersion engineering and measurement in crystalline microresonators using a fiber ring etalon

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Photonics Research 2021年第11期9卷 2222-2229页

作者： XIAOBAO ZHANG GUOPING LIN TANG SUN QINGHAI SONG GUANGZONG XIAO HUI LUO Ministry of Industry and Information Technology Key Laboratory of Micro-Nano Optoelectronic Information System School of ScienceHarbin Institute of TechnologyShenzhen 518055China College of Advanced Interdisciplinary Studies National University of Defense TechnologyChangsha 410073China

Dispersion engineering and measurement are significant for nonlinear photonic applications using whispering gallery mode ***,the Kerr microresonator frequency comb as an important example has attracted a great amount of interest in research fields due to the potential capability of full integration on a chip.A simple and cost-efficient way for dispersion measurements is thereby in high demand for designing such a microcomb ***,we report a dispersion measurement approach using a fiber ring etalon *** free spectral range of the etalon is first measured through sideband modulation,and the dispersion of the etalon is inferred by binary function fitting during the dispersion *** method is demonstrated on two MgF_(2) disk *** results show good agreement with numerical simulations using the finite element *** engineering on such resonators is also numerically investigated.

关键词： fiber resonator Dispersion

Nonequilibrium carrier and phonon dynamics in the ferrimagnetic semiconductor Mn3Si2Te6

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arXiv 2024年

作者： Yang, Y. Chen, X.T. Li, Z.L. Pan, J.B. Jing, F. Zhang, S.S. Wang, X.B. Luo, J.L. Key Laboratory of Education Ministry for Laser and Infrared System Integration Technology Shandong University Qingdao266237 China Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing100190 China School of Information Science and Engineering Shandong University Qingdao266237 China

We investigate the ultrafast carrier and phonon dynamics in the ferrimagnetic semiconductor Mn3Si2Te6 using time-resolved optical pump-probe spectroscopy. Our results reveal that the electron-phonon thermalization process with a subpicosecond timescale is prolonged by the hot-phonon bottleneck effect. We identify the subsequent relaxation processes associated with two non-radiative recombination mechanisms, i.e., phonon-assisted electron-hole recombination and defect-related Shockley-Read-Hall recombination. Temperature-dependent measurements indicate that all three relaxation components show large variation around 175 and 78 K, which is related to the initiation of spin fluctuation and ferrimagnetic order in Mn3Si2Te6. In addition, two pronounced coherent optical phonons are observed, in which the phonon with a frequency of 3.7 THz is attributed to the A1g mode of Te precipitates. Applying the strain pulse propagation model to the coherent acoustic phonons yields a penetration depth of 506 nm and a sound speed of 2.42 km/s in Mn3Si2Te6. Our results develop understanding of the nonequilibrium properties of the ferrimagnetic semiconductor Mn3Si2Te6, and also shed light on its potential applications in optoelectronic and spintronic devices. Copyright © 2024, The Authors. All rights reserved.

关键词： Phonons

Air-Ground Integrated Online Federated Learning Under Unreliable Communication

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IEEE Transactions on Cognitive Communications and Networking 2025年

作者： Jing, Yuqian Qu, Yuben Wu, Tao Dong, Chao Guo, Song Wu, Qihui Ministry of Industry and Information Technology Key Laboratory of Dynamic Cognitive System of Electromagnetic Spectrum Space China Nanjing University of Aeronautics and Astronautics College of Electronic and Information Engineering Nanjing211106 China Hong Kong Polytechnic University Department of Computing Hong Kong Hong Kong National University of Defense Technology Anhui Hefei230009 China Hong Kong University of Science and Technology Department of Computer Science and Engineering Hong Kong999077 Hong Kong

In recent years, unmanned aerial vehicles (UAVs) equipped with intelligent computing modules for machine learning (ML) have garnered attention. Federated learning (FL), as an emerging distributed learning paradigm, aligns seamlessly with this scenario. UAVs train local models while a terrestrial base station (BS) aggregates the global model, forming an air-ground integrated federated learning (AGIFL) system. However, under air-ground integrated networks with unreliable wireless links, the online retraining of ML models with new samples is promising but challenging in AGIFL. To this end, we study how to enhance the performance of air-ground integrated online FL (AGIOFL) considering packet transmission error. Specifically, we formulate a joint optimization problem for sample selection and client scheduling, aiming to minimize the loss function that maximizes the performance of AGIOFL. To solve the aforementioned problem without explicit expression, we first derive a closed-form expression for the expected convergence rate of the FL algorithm to quantify the impact of AGIOFL and unreliable wireless transmission. Based on this relationship, we reformulate the optimization problem into a mixed-integer nonlinear programming problem. Subsequently, we develop an alternating iterative optimization algorithm (OFL-PE) combining branch-and-bound with the Dinkelbach algorithm to solve this problem. Simulations indicate that OFL-PE converges within 10 iterations only, with a maximum error of less than 7% compared to the exhaustive brute force approach. In addition, we construct a proof-of-concept system based on widely used UAV embedded computers, and experimental results show that OFL-PE demonstrates superior accuracy, convergence, and robustness compared to three existing FL algorithms. © 2015 IEEE.

关键词： Federated learning

Humidity Sensing Properties of Different Atomic Layers of Graphene on SiO2/Si Substrate

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arXiv 2024年

作者： Gao, Qiang Ma, Hongliang He, Chang Wang, Xiaojing Ding, Jie Zhang, Wendong Fan, Xuge Advanced Research Institute for Multidisciplinary Science Beijing Institute of Technology Beijing100081 China Center for Interdisciplinary Science of Optical Quantum and NEMS Integration Beijing Institute of Technology Beijing100081 China School of Integrated Circuits and Electronics Beijing Institute of Technology Beijing100081 China Advanced Interdisciplinary Technology Research Center National Innovation Institute of Defense Technology Beijing100071 China State Key Laboratory of Dynamic Measurement Technology North University of China Taiyuan030051 China National Key Laboratory for Electronic Measurement Technology School of Instrument and Electronics North University of China Taiyuan030051 China Beijing Institute of Technology Zhuhai Beijing Institute of Technology Zhuhai519088 China

Graphene has the great potential to be used for humidity sensing due to ultrahigh surface area and conductivity. However, the impact of different atomic layers of graphene on SiO2/Si substrate on the humidity sensing have not been studied yet. In this paper, we fabricated three types of humidity sensors on SiO2/Si substrate based on one to three atomic layers of graphene, in which the sensing areas of graphene are 75 μm × 72 μm and 45 μm × 72 μm, respectively. We studied the impact of both the number of atomic layers of graphene and the sensing areas of graphene on the responsivity and response/recovery time of the prepared graphene-based humidity sensors. We found the relative resistance change of the prepared devices decreased with the increase of number of atomic layers of graphene under the same change of relative humidity. Further, devices based on tri-layer graphene showed the fastest response/recovery time while devices based on double-layer graphene showed the slowest response/recovery time. Finally, we chose the devices based on double-layer graphene that have relatively good responsivity and stability for application in respiration monitoring and contact-free finger monitoring. © 2024, CC BY-NC-SA.

关键词： Humidity sensors

8D Parameters Estimation for Bistatic EMVS-MIMO Radar via the nested PARAFAC

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arXiv 2022年

作者： Xie, Qianpeng Wang, He Du, Yihang Pan, Xiaoyi Zhao, Feng The State Key Laboratory of Complex Electromagnetic Environment Effects on Electronics and Information System National University of Defense Technology Changsha410073 China The School of Electronic Science National University of Defense Technology Changsha410073 China The Sixty-Third Research Institute National University of Defense Technology Nanjing210007 China

In this letter, a novel nested PARAFAC algorithm was proposed to improve the 8D parameters estimation performance for the bistatic EMVS-MIMO radar. Firstly, the outer part PARAFAC algorithm was carried out to estimate the receive spatial response matrix and its first way factor matrix. For the estimated first way factor matrix, a theory is given to rearrange its data into an new matrix, which is the mode-1 unfolding matrix of a three-way tensor. Then, the inner part PARAFAC algorithm was used to estimate the transmit steering vector matrix, the transmit spatial response matrix and the receive steering vector matrix. Thus, the transmit 4D parameters and receive 4D parameters can be accurately located via the abovementioned process. Compared with the original PARAFAC algorithm, the proposed nested PARAFAC algorithm can avoid additional reconstruction process when estimating the transmit/receive spatial response matrix. Moreover, the proposed algorithm can offer a highly-accurate 8D parameters estimaiton than that of the original PARAFAC algorithm. Simulated results verify the effectiveness of the proposed algorithm. Copyright © 2022, The Authors. All rights reserved.

关键词： Parameter estimation

Efficient Edge Intelligence under Clustering for UAV Swarm Networks

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Efficient Edge Intelligence under Clustering for UAV Swarm N...

2021 IEEE International Conference on Space-Air-Ground Computing, SAGC 2021

作者： Qu, Yuben Dong, Chao Wu, Tao Zhuang, Yan Dai, Haipeng Wu, Fan Nanjing University of Aeronautics and Astronautics The Key Laboratory of Dynamic Cognitive System of Electromagnetic Spectrum Space Ministry of Industry and Information Technology China National University of Defense Technology China Shanghai Jiao Tong University Department of Computer Science and Engineering China Nanjing University State Key Laboratory for Novel Software Technology China

ISBN: (纸本)9781665400114

Unmanned aerial vehicles (UAVs) are expected to be widely used in many critical applications including monitoring, surveillance, urban target tracking, and delivery of goods, from military to civil fields. To realize that, empowering UAV swarm with edge intelligence is becoming appealing and inevitable. Federated learning (FL) as an emerging distributed collaborative machine learning (ML) without letting raw data out, could be suitable for UAV swarm networks but remains largely unexplored. In this paper, we first investigate the problem of efficient Edge Intelligence under Clustering for UAV swarm networks (e-EIC), i.e., how to jointly optimize the computation resource allocation and UAV clustering to minimize the total energy consumption of the UAV swarm for FL, subject to the training accuracy and latency constraints. We decompose the challenging e-EIC problem into two subproblems: computation resource allocation and UAV clustering, and accordingly propose an iterative algorithm based on the optimal policy of the first subproblem and local-search techniques for the second subproblem. Extensive performance evaluations demonstrate that our proposed algorithm can reduce more energy consumption of UAVs than three baseline algorithms, while satisfying the training accuracy and latency constraints. © 2021 IEEE.

关键词： Energy utilization