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Two-layer Lagrange-based relay network topology and trajectory design for solar system explorations

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Science China(Information Sciences) 2024年第6期67卷 342-358页

作者： jun CAO Jian JIAO Hao liu Rongxing LU Qinyu ZHANG Guangdong Provincial Key Laboratory of Aerospace Communication and Networking Technology Harbin Institute of Technology (Shenzhen) Faculty of Computer Science (FCS) University of New Brunswick

Exploration targeting outer planets and even the edge of the solar system is an emerging direction for the deep-space exploration in the next decades. To address this challenge, a novel two-layer Lagrangebased relay network topology is proposed in this study. Specifically, we utilize the Sun-Mars and Sun-Saturn Lagrange points(LPs) L4 and L5 to build a two-layer backbone relay network, which ensures continuous and high-efficiency communication capability for the exploration of the solar system. Furthermore, we utilize the planetary gravity assist and design the transfer trajectory of backbone relays with the help of planetary celestial body motion equations and Kepler's laws. Moreover, we conduct link budget analysis for multihop relay transmission under Gamma-Gamma distribution, shadowed Rician fading, and additive white Gaussian noise channels in several typical exploration scenarios and validate that the LP relays can effectively support future deep-space exploration missions.

关键词： deep-space communication Lagrangian points backbone relay network transfer trajectory relay selection

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一个安全公钥广播加密方案(英文)

软件学报 2005年第7期16卷 1333-1343页

作者：谭作文刘卓军肖红光中国科学院数学与系统科学院系统科学研究所长沙理工大学电子信息工程系湖南长沙410076

消息的发送者使用广播加密算法通过广播信道将消息发送给用户.公钥加密算法和追踪算法结合在一起,可构成一个公钥广播加密方案.提出了一个完全式公钥广播加密方案.在以往公钥广播加密方案中,消息发送中心替每个用户选择解密私钥,分配解... 详细信息

消息的发送者使用广播加密算法通过广播信道将消息发送给用户.公钥加密算法和追踪算法结合在一起,可构成一个公钥广播加密方案.提出了一个完全式公钥广播加密方案.在以往公钥广播加密方案中,消息发送中心替每个用户选择解密私钥,分配解密私钥.而在完全式公钥广播加密方案中,用户的解密私钥是由用户自己所选择的.用户可以随时加入或退出广播系统.当消息发送者发现非法用户时,不要求合法用户作任何改变,就能够很方便地取消这些非法用户.此外,证明了方案中加密算法在DDH假设和适应性选择密文攻击下是安全的.

关键词：广播加密可证安全 black-box追踪适应性攻击

The Astrometric Performance of the China Space Station Telescope(CSST)Sky Survey in Extending the Gaia Celestial Reference Frame

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Research in Astronomy and Astrophysics 2024年第8期24卷 133-140页

作者： jun Yao Jia-Cheng liu Niu liu Zi Zhu Zhen-Wei Wang School of Astronomy and Space Science Key Laboratory of Modern Astronomy and Astrophysics(Ministry of Education)Nanjing UniversityNanjing 210023China University of Chinese Academy of Sciences Nanjing 211135China

The multi-color imaging sky survey conducted by the China Space Station Telescope(CSST)holds significant promise for advancing the development of the celestial reference *** this study,we focus on assessing the astrometric performance of the CSST celestial reference frame(CSST-CRF)in extending the Gaia Celestial Reference Frame 3(Gaia-CRF3).First,the orientation precision of the CSST reference frame is evaluated using a simulated set of extragalactic sources with CSST g magnitudes ranging from 18 to 25 *** estimated orientation uncertainty caused by random error insignificantly affects the alignment between Gaia-CRF3 and the ***,the systematic effect of incomplete CSST sky coverage on the alignment between CSST-CRF and Gaia-CRF3 is discussed by analyzing the differences between the subset of Gaia-CRF3 in the CSST observation region(Gaia-CRF3′)and Gaia-CRF3 as a *** the third International Celestial Reference Frame(ICRF3)S/X band as an intermediate reference frame,the orientation offset between Gaia-CRF3′and GaiaCRF3 is estimated to be 20μ*** offset is marginally larger than the orientation offset between Gaia-CRF3 and the ICRF3,approximately 15μ*** residual spin and glide rate of Gaia-CRF3′are derived from the proper motions,consistent with that of Gaia-CRF3 within the formal ***,we explore the role of CSST in establishing a multi-band celestial reference frame by comparing its limiting magnitude and observation accuracy with existing catalogs in the infrared and ultraviolet *** to its broad wavelength coverage and highprecision measurements,CSST is well-positioned to make significant contributions to the development of a multiband celestial reference frame.

关键词： astrometry reference systems surveys

Unstructured Road Extraction in UAV Images based on Lightweight Model

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 372-384页

作者： Di Zhang Qichao An Xiaoxue Feng Ronghua liu jun Han Feng Pan School of Automation Beijing Institute of TechnologyBeijing 100081China Tianjin Institute of Maritime Navigation Instruments Tianjin 300130China The 716th Research Institute of China Shipbuilding Group Co. LtdJiangsu 222061China

There is no unified planning standard for unstructured roads,and the morphological structures of these roads are complex and *** is important to maintain a balance between accuracy and speed for unstructured road extraction *** road extraction algorithms based on deep learning have problems such as high model complexity,high computational cost,and the inability to adapt to current edge computing ***,it is best to use lightweight network *** the need for lightweight models and the characteristics of unstructured roads with different pattern shapes,such as blocks and strips,a TMB(Triple Multi-Block)feature extraction module is proposed,and the overall structure of the TMBNet network is *** TMB module was compared with SS-nbt,Non-bottleneck-1D,and other modules via *** feasibility and effectiveness of the TMB module design were proven through experiments and *** comparison experiment,using multiple convolution kernel categories,proved that the TMB module can improve the segmentation accuracy of the *** comparison with different semantic segmentation networks demonstrates that the TMBNet network has advantages in terms of unstructured road extraction.

关键词： Unstructured road Lightweight model Triple Multi-Block(TMB) Semantic segmentation net

Asymptotic Inference in the Random Coefficient Autoregressive Model with Time-functional Variance Noises

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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 320-346页

作者： En-wen ZHU Zi-wei DENG Han-jun ZHANG jun CAO Xiao-hui liu Department of Mathematics and Statistics Changsha University of Science and TechnologyChangsha 410114China School of Mathematics and Computational Science Xiangtan UniversityXiangtan 411105China School of Statistics and Data Science and Key Laboratory of Data Science in Finance and EconomicsJiangxi University of Finance and EconomicsNanchang 330013China

This paper considers the random coefficient autoregressive model with time-functional variance noises,hereafter the RCA-TFV *** first establish the consistency and asymptotic normality of the conditional least squares estimator for the constant *** semiparametric least squares estimator for the variance of the random coefficient and the nonparametric estimator for the variance function are constructed,and their asymptotic results are reported.A simulation study is presented along with an analysis of real data to assess the performance of our method in finite samples.

关键词： random coefficient autoregressive model time-functional variance conditional least squares semiparametric least squares

In Vivo Voltammetric Imaging of Metal Nanoparticle-Catalyzed Single-Cell Electron Transfer by Fermi Level-Responsive Graphene

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Research 2024年第1期2023卷 271-280页

作者： Qing Xia Rui liu Xueqin Chen Zixuan Chen jun-Jie Zhu State Key Laboratory of Analytical Chemistry for Life Science School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023P.R.China Shenzhen Research Institute of Nanjing University Shenzhen 518000P.R.China

Metal nanomaterials can facilitate microbial extracellular electron transfer(EET)in the electrochemically active ***,the role of nanomaterials/bacteria interaction in this process is still ***,we reported the single-cell voltammetric imaging of Shewanella oneidensis MR-1 at the single-cell level to elucidate the metal-enhanced EET mechanism in vivo by the Fermi level-responsive graphene *** oxidation currents of~20 fA were observed from single native cells and gold nanoparticle(AuNP)-coated cells in linear sweep voltammetry *** the contrary,the oxidation potential was reduced by up to 100 mV after AuNP *** revealed the mechanism of AuNP-catalyzed direct EET decreasing the oxidation barrier between the outer membrane cytochromes and the *** method offered a promising strategy to understand the nanomaterials/bacteria interaction and guide the rational construction of EET-related microbial fuel cells.

关键词： Fermi voltammetry Electron

Suppression of low-frequency ultrasound broadband vibration using star-shaped single-phase metamaterials

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Defence Technology（防务技术） 2024年第4期34卷 217-224页

作者： Rui Zhao Jian Zheng Jin Guo Yunbo Shi Hengzhen Feng jun Tang jun liu Science and Technology on Electronic Test&Measurement Laboratory North University of ChinaTaiyuan 030051ShanxiChina School of Mechatronical Engineering Beijing Institute of TechnologyBeijing 100081China

In order to suppress the low-frequency ultrasound vibration in the broadband range of 20 k Hz—100 k Hz,this paper proposes and discusses an acoustic metamaterial with low-frequency ultrasound vibration attenuation properties,which is configured by hybrid arc and sharp-angle convergent star-shaped *** effect of the dispersion relation and the bandgap characteristic for the scatterers in star-shaped are simulated and *** target bandgap width is extended by optimizing the geometry parameters of arc and sharp-angle convergent *** proposed metamaterial configured by optimized hybrid lattices exhibits remarkable broad bandgap characteristics by bandgap complementarity,and the simulation results verify a 99%vibration attenuation amplitude can be obtained in the frequency of20 k Hz—100 k *** the fabrication of the proposed hybrid configurational star-shaped metamaterial by 3D printing technique,the transmission loss experiments are performed,and the experimental results indicate that the fabricated metamaterial has the characteristics of broadband vibration attenuation and an amplitude greater than 85%attenuation for the target *** results demonstrate that the hybrid configurational star-shaped metamaterials can effectively widen the bandgap and realize high efficiency attenuation,which has capability for the vibration attenuation in the application of highprecise equipment.

关键词： Star-shaped metamaterials Broadband Vibration attenuation Low-frequency ultrasound vibration Transmission loss

Activatable fluorescent probes for imaging and diagnosis of rheumatoid arthritis

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Military Medical Research 2024年第2期11卷 287-307页

作者： Pan Luo Fu-Qiang Gao Wei Sun jun-You Li Cheng Wang Qing-Yu Zhang Zhi-zhuo Li Peng Xu Department of Joint Surgery Honghui HospitalXi'an Jiaotong UniversityXi'an 710054China Department of Orthopedics China-Japan Friendship HospitalBeijing 100029China Department of Orthopaedic Surgery of the Perelman School of Medicine University of PennsylvaniaPhiladelphiaPA 19104USA School of Mechanical Engineering Sungkyunkwan UniversitySuwon 16419South Korea Department of Orthopaedic Surgery Peking University Third HospitalPeking UniversityBeijing 100191China Department of Orthopedics Shandong Provincial Hospital Affiliated to Shandong First Medical UniversityJinan 250021China State Key Laboratory of Pharmaceutical Biotechnology Division of Sports Medicine and Adult Reconstructive SurgeryDepartment of Orthopedic SurgeryNanjing Drum Tower Hospitalthe Affiliated Hospital of Nanjing University Medical SchoolNanjing 210008China

Rheumatoid arthritis(RA)is a systemic autoimmune disease that is primarily manifested as synovitis and polyarticular opacity and typically leads to serious joint damage and irreversible disability,thus adversely affecting locomotion ability and life ***,good prognosis heavily relies on the early diagnosis and effective therapeutic monitoring of *** fluorescent probes play vital roles in the detection and imaging of biomarkers for disease diagnosis and in vivo ***,we review the fluorescent probes developed for the detection and imaging of RA biomarkers,namely reactive oxygen/nitrogen species(hypochlorous acid,peroxynitrite,hydroxyl radical,nitroxyl),pH,and cysteine,and address the related challenges and prospects to inspire the design of novel fluorescent probes and the improvement of their performance in RA studies.

关键词： Rheumatoid arthritis Fluorescent probe Imaging Diagnosis Biomarker

Magnetic nanoparticle-modified hollow double-shell SiC@C@FeCo with excellent electromagnetic wave absorption

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Nano Research 2024年第4期17卷 3164-3174页

作者： Guiyu Peng Jintang Zhou Jiaqi Tao Weize Wang jun liu junru Yao Yijie liu Zhengjun Yao College of Materials Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211100China Key Laboratory of Material Preparation and Protection for Harsh Environment(Nanjing University of Aeronautics and Astronautics) Ministry of Industry and Information TechnologyNanjing 211100China

Integrated micro and nanostructures,heterogeneous components,defects,and interfaces is the way to develop high-performance microwave absorbing ***,there still needs to be more precise experimental routes and effective *** this work,by a continuous process of vacuum sintering,hydrothermal,and carbon thermal reduction,magnetic FeCo nanoparticles were successfully embedded on the hollow double-shell mesoporous SiC@C surface,thus solving the challenges of a single component loss *** hollow double-shell nanostructure introduces air to enhance impedance matching while significantly reducing the density of the *** extensive defects and heterogeneous grain boundaries effectively enhance the polarization loss *** magnetic loss mechanism introduced by the magnetic particles effectively improves the impedance matching properties of the *** synergy of these multiple advantages has enabled the SCFC_(2)-8(here SiC@C@FeCo is abbreviated to SCFC,2 represents the initial metal ion content,and 8 represents the hydrothermal time)sample to achieve an adequate absorption bandwidth of 6.09 GHz at 2.0 *** a minimum reflection loss of-60.56 dB,the absorption bandwidth can cover the entire C,X,and Ku bands by adjusting the matching thickness(1.3–4.0 mm).This work provides a valuable paradigm for the deeper exploitation of microwave absorption potential and guides the development of other high-performance materials.

关键词： SiC@C@FeCo(SCFC)composites core–shell hollow structure microwave absorption