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Seeing at a distance with multicore fibers

Opto-Electronic Advances 2024年第7期7卷 39-49页

作者： Haogong feng Xi chen Runze Zhu Yifeng Xiong Ye chen Yanqing Lu Fei Xu National Laboratory of Solid State Microstructures College of Engineering and Applied Sciencesand Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China College of Physics MIIT Key Laboratory of Aerospace Information Materials and PhysicsState Key Laboratory of Mechanics and Control for Aerospace StructuresNanjing University of Aeronautics and AstronauticsNanjing 211106China

Images and videos provide a wealth of information for people in production and *** most digital information is transmitted via optical fiber,the image acquisition and transmission processes still rely heavily on electronic *** development of all-optical transmission networks and optical computing frameworks has pointed to the direction for the next generation of data transmission and information ***,we propose a high-speed,low-cost,multiplexed parallel and one-piece all-fiber architecture for image acquisition,encoding,and transmission,called the Multicore Fiber Acquisition and Transmission Image System(MFAT).Based on different spatial and modal channels of the multicore fiber,fiber-coupled self-encoding,and digital aperture decoding technology,scenes can be observed directly from up to 1 km *** expansion of capacity provides the possibility of parallel coded transmission of multimodal high-quality *** requires no additional signal transmitting and receiving *** all-fiber processing saves the time traditionally spent on signal conversion and image pre-processing(compression,encoding,and modulation).Additionally,it provides an effective solution for 2D information acquisition and transmission tasks in extreme environments such as high temperatures and electromagnetic interference.

关键词： long-distance fiber imaging image transmission parallel transmission all-optical encoding multicore fiber

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Transient flameout process of boron-magnesium agglomerates during combustion in oxygen-rich atmospheres

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Particuology 2024年第5期88卷 290-301页

作者： Lian Duan Zhixun Xia Yunchao feng Binbin chen Likun Ma Jianxin Hu College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China School of Mechanical Engineering and Mechanics Xiangtan UniversityXiangtan 411105China

In this study,boron–magnesium agglomerates with varying mass ratios were prepared by drying a micron-sized boron–magnesium mixed suspension,and the combustion process of these agglomerates under different oxygen-rich concentrations were investigated using a laser ignition *** test results showed that when the mass fraction of magnesium powder in boron-magnesium agglomerates exceeded a certain threshold(between 2%and 5%),flame extinction and reignition occurred after a significant reduction in the agglomerate volume during *** process is referred to as the transient flameout process,which is affected by the magnesium content of the agglomerate and the oxygen concentration in the ambient *** increase in the magnesium content or oxygen concentration makes this phenomenon more *** weakening of the flame intensity,a dark film gradually covered the particle surfaces.X-ray diffraction and elemental analyses of the cross-section and outer surface of the condensed combustion product suggested that the dark film is primarily composed of Mg-B-O ternary *** film prevents direct contact between boron and oxygen,thereby inhibiting surface and gas-phase reactions and leading to the occurrence of the transient flameout phenomenon.

关键词： Agglomerated particle Boron–magnesium fuel Boron combustion Transient flameout process Solid fuel ramjet

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Towards complex scenes: A deep learning-based camouflaged people detection method for snapshot multispectral images

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Defence Technology（防务技术） 2024年第4期34卷 269-281页

作者： Shu Wang Dawei Zeng Yixuan Xu Gonghan Yang feng Huang Liqiong chen School of Mechanical Engineering and Automation Fuzhou UniversityFuzhou 350108China

Camouflaged people are extremely expert in actively concealing themselves by effectively utilizing cover and the surrounding environment. Despite advancements in optical detection capabilities through imaging systems, including spectral, polarization, and infrared technologies, there is still a lack of effective real-time method for accurately detecting small-size and high-efficient camouflaged people in complex real-world scenes. Here, this study proposes a snapshot multispectral image-based camouflaged detection model, multispectral YOLO(MS-YOLO), which utilizes the SPD-Conv and Sim AM modules to effectively represent targets and suppress background interference by exploiting the spatial-spectral target information. Besides, the study constructs the first real-shot multispectral camouflaged people dataset(MSCPD), which encompasses diverse scenes, target scales, and attitudes. To minimize information redundancy, MS-YOLO selects an optimal subset of 12 bands with strong feature representation and minimal inter-band correlation as input. Through experiments on the MSCPD, MS-YOLO achieves a mean Average Precision of 94.31% and real-time detection at 65 frames per second, which confirms the effectiveness and efficiency of our method in detecting camouflaged people in various typical desert and forest scenes. Our approach offers valuable support to improve the perception capabilities of unmanned aerial vehicles in detecting enemy forces and rescuing personnel in battlefield.

关键词： Camouflaged people detection Snapshot multispectral imaging Optimal band selection MS-YOLO Complex remote sensing scenes

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Dynamic Crosslinked Phosphorescent Poly(vinyl alcohol)-Terpyridine Films with Enhanced Mechanical Properties and Tunable Shape Memory

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Chinese Journal of Polymer Science 2024年第10期42卷 1595-1601,I0015页

作者： Meng Wei Wei-Hao feng chen Yu Zhen-Yi Jiang Guang-Qiang Yin Wei Lu Tao chen Key Laboratory of Advanced Marine Materials Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo315201China School of Chemical Sciences University of Chinese Academy of SciencesBeijing100049China School of Materials Science and Chemical Engineering Ningbo UniversityNingbo315211China

Achieving versatile room temperature phosphorescence(RTP)materials,especially with tunable mechanical properties and shape memory is attractive and essential but rarely ***,a strategy was reported to realize multi-functional RTP films with multicolor fluorescence,ultralong afterglow,adjustable mechanical properties,and shape memory through the synergistic dynamic interaction of lanthanide(Ln~Ⅲ)-terpyridine coordination,borate ester bonds,and hydrogen bondings in a poly(vinyl alcohol)(PVA)*** varying the amount of borax,the mechanical properties of the films could be finely controlled due to the change of crosslinking degree of dynamic borate ester bonds in *** assembly and disassembly of borate ester bonds upon the trigger of borax and acid were applied as reversible linkage to achieve programmable shape memory *** addition,the films displayed both fascinating multicolor fluorescence and ultralong afterglow characteristics due to the presence of Ln III doping and confinement of terpyridine in *** study provides a new avenue to impart modulable mechanical strength and shape memory to RTP materials.

关键词： Room temperature phosphorescence materials Dynamic bonds Multicolor fluorescent Tunable mechanical properties Shape memory

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Fabrication of AZ31/Mg3Y Composites with Excellent Strength and Plasticity via Accumulated Rolling Bonding and Diffusion Annealing

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Acta Metallurgica Sinica(English Letters) 2024年第2期37卷 339-352页

作者： Yang feng Wenhuan chen Zheng Xu Weijun He Bin Jiang Fusheng Pan College of Materials Science and Engineering Chongqing UniversityChongqing400044China International Joint Laboratory for Light Alloys(Ministry of Education) Chongqing UniversityChongqing400044China

AZ31/Mg3Y composites with a layer thickness of 100-200μm were fabricated by accumulated rolling bonding(ARB),which was followed by diffusion annealing at 300℃ for 0-32 *** interface layer,containing numerous Al-Y precipitates,is formed in the Mg3Y layer that is adjacent to the interface as a result of Al diffusing from the AZ31 layers into the Mg3Y *** thickness of the interface layer gets increased and more precipitates are formed in the interface layer with the extension of the annealing *** microhardness of the AZ31 and Mg3Y layer decreases firstly and then reaches a stable value,while the microhardness of the interface layer increases gradually with the extension of the annealing *** AZ31/Mg3Y composites exhibit equivalent strength but increased ductility after diffusion annealing,in comparison to the as-rolled AZ31/Mg3Y *** addition,the AZ31/Mg3Y composites after annealing always present higher strength and ductility than AZ31/AZ31 composite,which was fabricated by the same process as that for the AZ31/Mg3Y ***-deformation induced strengthening also plays an important role in the excellent strength and ductility of the annealed AZ31/Mg3Y *** study can provide a direction for improving the plasticity and strength of magnesium alloys synergistically.

关键词： AZ31/Mg3Y composite Accumulated rolling bonding Diffusion annealing Precipitates Strengthening

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High-frequency Resonance Analysis and Impedance Reshaping Control of MMC-HVDC System Based on Frequency Coupling Impedance Model

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Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 646-657页

作者： Juanjuan Wang Wei chen Yuekun Liu Chuang Fu Yunming Ye Junjie feng School of Electric Power South China University of TechnologyGuangzhouChina Guangdong Power Grid Co. Ltd.GuangzhouChina Electric Power Research Institute China Southern Power GridGuangzhouChina

In recent years, high-frequency resonance (HFR) events occurred in several modular multilevel converter based high-voltage direct current (MMC-HVDC) projects. The time delay of an MMC-HVDC system is the critical factor that induces HFR. The frequency coupling affects the impedance characteristics of an MMC and further deteriorates system stability. Therefore, in this paper, a multi-input multi-output admittance model of an MMC-HVDC system is developed to analyze its frequency characteristics. The effects of current loop, power loop, phase-locked loop, and operating point on the MMC frequency coupling degree are analyzed in detail. Meanwhile, to further suppress HFR in the MMC-HVDC system, an enhanced impedance reshaping control strategy based on the equivalent single-input single-output impedance model is proposed. Finally, the accuracy of the enhanced impedance model and the effectiveness of the impedance reshaping control are verified by electromagnetic transient simulations in PSCAD.

关键词： Modular multilevel converter based high-voltage direct current(MMC-HVDC) high-frequency resonance frequency coupling impedance model impedance reshaping control

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A fibrous hydroelectric generator derived from eco-friendly sodium alginate for low-grade energy harvesting

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Frontiers in Energy 2024年第4期18卷 474-482页

作者： feng GONG Jiaming SONG Haotian chen Hao LI Runnan HUANG Yuhang JING Peng YANG Junjie feng Rui XIAO Key Laboratory of Energy Thermal Conversion and Control of the Ministry of Education School of Energy and EnvironmentSoutheast UniversityNanjing 210096China

With the development of renewable energy technologies,the recovery and utilization of low-grade energy based on hydroelectric effect have drawn much attention owing to its environmental ***,a novel hydroelectric generator utilizing sodium alginategraphene oxide(SA-GO)fibers is proposed,which is ecofriendly and *** fibers with a length of 5 cm and a diameter of 0.15 mm can generate an open circuit voltage(Voc)of approximately 0.25 V and a short circuit current(Isc)of 4µ*** connecting SA-GO fibers in either series or parallel,this combination can power some electronic ***,these fibers enable the recovery of low-grade energy from the atmosphere or around the human *** experimental and theoretical analysis confirm that the directional flow of protons driven by water molecules is the main mechanism for power generation of SA-GO *** study not only presents a simple energy transformation method that is expected to be applied to our daily life,but also provides a novel idea for the design of humidity electricity-generation devices.

关键词： fibrous hydroelectric generator sodium alginate(SA) graphene oxide(GO) power generation

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Simulation design of thin film lithium niobate electro-optic modulator with bimetallic layer electrodes

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Optoelectronics Letters 2024年第6期20卷 339-345页

作者： WU Qiulin feng Xinkai chen Jiaying MA Lei chen Huaixi LIANG Wanguo Fujian Institute of Research on the Structure of Matter Chinese Academy of SciencesFuzhou 350108China University of Chinese Academy of Sciences Beijing 100059China Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108China1

Thin-film lithium niobate electro-optical modulator will become the key device in the future optical communication,which has the advantages of high modulation rate,low half-wave voltage,large bandwidth,and easy integration compared with conventional bulk lithium niobate ***,because the electrode gap of the lithium niobate film modulator is very narrow,when the microwave frequency gets higher,it leads to higher microwave loss,and the electro-optical performance of the modulator will be greatly ***,we propose a thin film lithium niobate electro-optic modulator with a bimetallic layer electrode structure to achieve microwave loss less than 8 dB/cm in the range of 200 GHz,exhibiting a voltage-length product of 1.1 V·cm and a 3 dB electro-optic bandwidth greater than 160 ***-speed data transmission test has been performed,showing good performance.

关键词： Simulation design of thin film lithium niobate electro-optic modulator with bimetallic layer electrodes

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Iterative Signal Detection Based Soft Interference Cancellation for Satellite-Terrestrial Downlink NOMA Systems

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China Communications 2024年第8期21卷 249-263页

作者： Sun Meng Zhang Qi Yao Haipeng Gao Ran Xin Xiangjun Tian feng feng Weiying chen Dong School of Electronic Engineering Beijing University of Posts and Telecommunications(BUPT)Beijing 100876China Beijing Key Laboratory of Space-Ground Interconnection and Convergence State Key Laboratory of Information Photonics and Optical CommunicationsSchool of Electronic EngineeringBeijing University of Posts and Telecommunications(BUPT)Beijing 100876China School of Information and Communication Engineering Beijing University of Posts and Telecommunications(BUPT)Beijing 100876China Beijing Institute of Technology Beijing 100081China Beihang University Beijing 100191China China Academy of Space Technology(CAST) Beijing 100094China

To improve the bit error rate(BER)performance of multi-user signal detection in satelliteterrestrial downlink non-orthogonal multiple access(NOMA)systems,an iterative signal detection algorithm based on soft interference cancellation with optimal power allocation is *** that power allocation has a significant impact on BER performance,the optimal power allocation is obtained by minimizing the average BER of NOMA *** to the allocated powers,successive interference cancellation(SIC)between NOMA users is performed in descending power *** each user,an iterative soft interference cancellation is performed,and soft symbol probabilities are calculated for soft *** improve detection accuracy and without increasing the complexity,the aforementioned algorithm is optimized by adding minimum mean square error(MMSE)signal estimation before detection,and in each iteration soft symbol probabilities are utilized for soft-decision of the current user and also for the update of soft interference of the previous *** results illustrate that the optimized algorithm ***-IDBSIC significantly outperforms joint multi-user detection and SIC detection by 7.57dB and 8.03dB in terms of BER performance.

关键词： non-orthogonal multiple access(NOMA) resource allocation satellite-terrestrial communication signal detection soft interference cancellation

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Research advances of nanoparticles for CAR-T therapy in solid tumors

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Chinese Chemical Letters 2024年第9期35卷 72-82页

作者： Bohan chen Liming Gong Jing feng Mingji Jin Liqing chen Zhonggao Gao Wei Huang State Key Laboratory of Bioactive Substance and Function of Natural Medicines Department of PharmaceuticsInstitute of Materia MedicaChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100050China Beijing Key Laboratory of Drug Delivery Technology and Novel Formulations Institute of Materia MedicaChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100050China School of Pharmacy Qingdao UniversityQingdao 266071China

As one of the most promising adoptive T-cell therapies,chimeric antigen receptor T-cell(CAR-T)therapy has acquired Food and Drug Administration(FDA)approval for a variety of products and has been used successfully in the treatment of malignant hematological ***-T therapy,on the other hand,faces a number of obstacles in the field of solid tumor therapy that limit its widespread clinical *** advances in nanoparticle research in cancer therapy and immunotherapy have been made in recent years,providing novel strategies to address the challenges encountered by CAR-T therapy in the treatment of solid *** review commences with a comprehensive explanation of the basic framework of CAR-T therapy as well as the challenges it faces in the treatment of solid ***,we encapsulate a summary of the developmental research combining nanoparticles with CAR-T cells for the treatment of solid tumors,which includes gene transfection,cell activation and expansion,targeted infiltration,immune escape inhibition,and combination with other *** with the overview of the research progress,a discussion has been initiated on the challenges and perspectives of CAR-T based on nanoparticles.

关键词： CAR-T therapy Nanoparticles Solid tumors Immunotherapy T cell

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