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Reinforcement learning based edge computing in B5G

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Digital Communications and Networks 2024年第1期10卷 1-6页

作者： Jiachen Yang Yiwen sun Yutian lei Zhuo Zhang Yang Li Yongjun Bao Zhihan Lv School of Electrical and Information Engineering Tianjin UniversityTianjin300072China Technology and Data Center ***Beijing100176China School of Data Science and Software Engineering Qingdao UniversityQingdao266101China

The development of communication technology will promote the application of Internet of Things,and Beyond 5G will become a new technology *** the same time,Beyond 5G will become one of the important supports for the development of edge computing *** paper proposes a communication task allocation algorithm based on deep reinforcement learning for vehicle-to-pedestrian communication scenarios in edge *** trial and error learning of agent,the optimal spectrum and power can be determined for transmission without global information,so as to balance the communication between vehicle-to-pedestrian and *** results show that the agent can effectively improve vehicle-to-infrastructure communication rate as well as meeting the delay constraints on the vehicle-to-pedestrian link.

关键词： Reinforcement learning Edge computing Beyond 5G Vehicle-to-pedestrian

Fast-Charging Sodium-Ion Batteries Enabled by Molecular-Level Designed Nitrogen and Phosphorus Codoped Mesoporous Soft Carbon

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Research 2024年第2期2023卷 329-337页

作者： lei Liu Zhuzhu Du Jiaqi Wang Hongfang Du Sheng Wu Mengjun Li Yixuan Zhang Jinmeng sun Zhipeng sun Wei Ai Frontiers Science Center for Flexible Electronics(FSCFE)and Shaanxi Institute of Flexible Electronics(SIFE) Northwestern Polytechnical University(NPU)127 West Youyi RoadXi'an 710072China Fujian Cross Strait Institute of Flexible Electronics(Future Technologies) Fujian Normal UniversityFuzhou 350117China School of Materials and Energy Guangdong University of TechnologyGuangzhou510006 GuangdongChina

Soft carbons have attracted extensive interests as competitive anodes for fast-charging sodium-ion batteries(SIBs);however,the high-rate performance is still restricted by their large ion migration barriers and sluggish reaction ***,we show a molecular design approach toward the fabrication of nitrogen and phosphorus codoped mesoporous soft carbon(NPSC).The key to this strategy lies in the chemical cross-linking reaction between polyphosphoric acid and p-phenylenediamine,associated with pyrolysis induced in-situ self-activation that creates mesoporous structures and rich heteroatoms within the carbon *** to the enlarged interlayer spacing,reduced ion diffusion length,and plentiful active sites,the obtained NPSC delivers a superb rate capacity of 215 mAh g-1 at 10 A g-1 and an ultralong cycle life of 4,700 cycles at 5 A g^(-1).Remarkably,the full cell shows 99%capacity retention during 100 continuous cycles,and maximum energy and power densities of 191 Wh kg^(-1)and 9.2 kW kg^(-1),*** believe that such a synthetic protocol could pave a novel venue to develop soft carbons with unique properties for advanced SIBs.

关键词： kinetics carbons linking

Palladium-Catalyzed[4+2]and[6+2]Dipolar Cycloadditions for the Construction of Benzo[d]isothiazole 1,1-Dioxide Fused 1,3-Oxazinanes and 1,3-Oxazocanes

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Chinese Journal of Chemistry 2024年第8期42卷 829-834页

作者： lei Chen Hongling Xie Yu Xue Zhengyu Han Jianwei sun Hai Huang Jiangsu Key Laboratory of Advanced Catalytic Materials&Technology School of Petrochemical EngineeringChangzhou UniversityChangzhouJiangsu213164 China Department of Chemistry The Hong Kong University of Science and TechnologyClear Water BayKowloonHong Kong SARChina

Comprehensive Summary,The Pd-catalyzed dipolar cycloaddition represents a significant synthetic strategy for the construction of useful heterocyclic *** study developed the dipolar[4+2]and[6+2]cycloaddition reactions of benzo[d]isothiazole 1,1-dioxides(BDs)leading to the synthesis of BD-fused 1,3-oxazinane and 1,3-oxazocane derivatives,*** particular,the synthesis of BD-fused 1,3-oxazinanes demonstrated regio-and enantioselective characteristics,resulting in products with good yields,enantioselectivity and regioselectivity(if applicable).Furthermore,the[6+2]cycloaddition reaction developed in this work represented the first strategy for the synthesis of medium-sized ring compounds based on BDs.

关键词： Cycloaddition 1,3-Oxazinanes 1,3-Oxazocanes Medium-ring compounds Stereochemistry N-Heterocycles Sulfonamides Enantioselectivity Asymmetricsynthesis

High-Precision Doppler Frequency Estimation Based Positioning Using OTFS Modulations by Red and Blue Frequency Shift Discriminator

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China Communications 2024年第2期21卷 17-31页

作者： Shaojing Wang Xiaomei Tang Jing lei Chunjiang Ma Chao Wen Guangfu sun School of Electronic Science National University of Defense TechnologyChangsha 410073China

Orthogonal Time Frequency and Space(OTFS) modulation is expected to provide high-speed and ultra-reliable communications for emerging mobile applications, including low-orbit satellite communications. Using the Doppler frequency for positioning is a promising research direction on communication and navigation integration. To tackle the high Doppler frequency and low signal-to-noise ratio(SNR) in satellite communication, this paper proposes a Red and Blue Frequency Shift Discriminator(RBFSD) based on the pseudo-noise(PN) *** paper derives that the cross-correlation function on the Doppler domain exhibits the characteristic of a Sinc function. Therefore, it applies modulation onto the Delay-Doppler domain using PN sequence and adjusts Doppler frequency estimation by red-shifting or blue-shifting. Simulation results show that the performance of Doppler frequency estimation is close to the Cramér-Rao Lower Bound when the SNR is greater than -15dB. The proposed algorithm is about 1/D times less complex than the existing PN pilot sequence algorithm, where D is the resolution of the fractional Doppler.

关键词： channel estimation communication and navigation integration Orthogonal Time Frequency and Space pseudo-noise sequence red-blue frequency shift discriminator

Localization in modified polar representation: hybrid measurements and closed-form solution

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Journal of Systems Engineering and Electronics 2024年第3期35卷 575-588页

作者： CONG Xunchao sun Yimao YANG Yanbing ZHANG lei CHEN Liangyin The 10th Research Institute of China Electronics Technology Group Corporation Chengdu 610036China College of Computer Science and Institute for Industrial Internet Research Sichuan UniversityChengdu 610065China

Classical localization methods use Cartesian or Polar coordinates, which require a priori range information to determine whether to estimate position or to only find bearings. The modified polar representation (MPR) unifies near-field and farfield models, alleviating the thresholding effect. Current localization methods in MPR based on the angle of arrival (AOA) and time difference of arrival (TDOA) measurements resort to semidefinite relaxation (SDR) and Gauss-Newton iteration, which are computationally complex and face the possible diverge problem. This paper formulates a pseudo linear equation between the measurements and the unknown MPR position,which leads to a closed-form solution for the hybrid TDOA-AOA localization problem, namely hybrid constrained optimization(HCO). HCO attains Cramér-Rao bound (CRB)-level accuracy for mild Gaussian noise. Compared with the existing closed-form solutions for the hybrid TDOA-AOA case, HCO provides comparable performance to the hybrid generalized trust region subproblem (HGTRS) solution and is better than the hybrid successive unconstrained minimization (HSUM) solution in large noise region. Its computational complexity is lower than that of HGTRS. Simulations validate the performance of HCO achieves the CRB that the maximum likelihood estimator (MLE) attains if the noise is small, but the MLE deviates from CRB earlier.

关键词： localization modified polar representation time difference of arrival(TDOA) angle of arrival(AOA) closed-form solution

A lithium–tin fluoride anode enabled by ionic/electronic conductive paths for garnet-based solid-state lithium metal batteries

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Rare Metals 2024年第2期43卷 575-587页

作者： lei Zhang Qian-Kun Meng Xiang-Ping feng Ming Shen Yu-Qing Zhang Quan-Chao Zhuang Run-Guo Zheng Zhi-Yuan Wang Yan-Hua Cui Hong-Yu sun Yan-Guo Liu School of Materials Science and Engineering Northeastern UniversityShenyang110819China School of Resources and Materials Northeastern University at QinhuangdaoQinhuangdao066004China School of Materials and Physics China University of Mining&TechnologyXuzhou221116China Institute of Electronic Engineering China Academy of Engineering PhysicsMianyang621900China

The high energy density and stability of solid-state lithium metal batteries(SSLMBs)have garnered great ***-type oxides,especially Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO),with high ionic conductivity,wide electrochemical window,and stability to Li metal anode,are promising solid-state electrolyte(SSEs)materials for ***,Li/LLZTO interface issues including high interface resistance,inhomogeneous Li deposition,and Li dendrite growth have hindered the practical application of ***,a multi-functional Li–SnF_(2) composite anode with Li,LiF,and Li-Sn alloy was specifically designed and *** composite anode improves the wettability to LLZTO,constructing an intimate contact interface between it and ***,ionic/electronic conductive paths in situ formed at the interface can effectively uniform Li deposition and suppress Li *** solid-state symmetric cell exhibits low interface resistance(11Ω·cm^(2)) and high critical current density(1.3 mA·cm^(−2))at 25℃.The full SSLMB based on LiFePO_(4) or LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2) cathode also shows stable cycling performance and high rate *** work provides a new composite anode strategy for achieving high-energy density and high-safety SSLMBs.

关键词： Solid-state lithium metal batteries(SSLMBs) Lithium-tin fluoride anode Ionic/electronic conductive Interface resistance Lithium dendrite

Subnanometric bimetallic Pt-Pd clusters in zeolites for efficient hydrogen production and selective tandem hydrogenation of nitroarenes

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Science China Chemistry 2024年第9期67卷 2911-2917页

作者： Jiafu Li Tao Cai Yanran feng Xia Liu Ning Wang Qiming sun Institute of Sustainable Energy and Resources College of Chemistry and Chemical EngineeringKey Laboratory of Shandong Provincial Universities for Functional Molecules and MaterialsQingdao UniversityQingdao 266071China Innovation Center for Chemical Sciences College of ChemistryChemical Engineering and Materials ScienceJiangsu Key Laboratory of Advanced Negative Carbon TechnologiesSoochow UniversitySuzhou 215123China

The solvolysis of ammonia borane(AB)and the hydrogenation of nitroarenes represent significant reactions for hydrogen generation and value-added chemical *** strategic engineering of the catalysts is imperative for surmounting obstacles associated with their stability and catalytic *** this work,subnanometric bimetallic Pt–Pd clusters were encapsulated within silicalite-1(S-1)zeolites through a ligand-protected in-situ hydrothermal synthesis *** synergetic effect of bimetallic composition and zeolite confinement markedly enhances the catalytic performance of representative Pt_(0.5)Pd_(0.5)@S-1-H catalyst,affording exceptional turnover frequency(TOF)values of 1,043 and 573 mol_(H_(2))mol_(metal)^(-1)min^(-1)for AB hydrolysis and methanolysis at ambient conditions,respectively,surpassing most of the state-of-the-art Pt-based *** and isotopic experiments reveal that the bimetallic catalytic system remarkably boosts the O-H cleavage of water,thereby facilitating the H_(2) production from AB ***,a conspicuous synergistic effect is demonstrated in the shape-selective tandem hydrogenation of nitroarenes,with the bimetallic catalyst facilitating both AB hydrolysis and nitroarene hydrogenation,giving a high TOF value of 1,260 h^(-1)under atmospheric *** study not only demonstrates the effectiveness of bimetallic nanocatalysts encapsulated in zeolites for hydrogen production from chemical hydrogen storage materials,but also paves the way for the design of catalysts with multifunctional active sites capable of synergistically promoting tandem catalytic processes.

关键词： subnanometer bimetallic cluster zeolite synergistic effect ammonia borane solvolysis selective tandem hydrogenation

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

The Spatiotemporal Distribution Characteristics of Cloud Types and Phases in the Arctic Based on CloudSat and CALIPSO Cloud Classification Products

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Advances in Atmospheric Sciences 2024年第2期41卷 310-324页

作者： Yue sun Huiling YANG Hui XIAO Liang feng Wei CHENG Libo ZHOU Weixi SHU Jingzhe sun Key Laboratory of Cloud-Precipitation Physics and Severe Storms(LACS) and Department of Lower Atmospheric Observation Research(LAOR)Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China College of Earth Sciences University of Chinese Academy of Sciences(UCAS)Beijing 100049China Beijing Institute of Applied Meteorology Beijing 100029China

The cloud type product 2B-CLDCLASS-LIDAR based on CloudSat and CALIPSO from June 2006 to May 2017 is used to examine the temporal and spatial distribution characteristics and interannual variability of eight cloud types(high cloud, altostratus, altocumulus, stratus, stratocumulus, cumulus, nimbostratus, and deep convection) and three phases(ice,mixed, and water) in the Arctic. Possible reasons for the observed interannual variability are also discussed. The main conclusions are as follows:(1) More water clouds occur on the Atlantic side, and more ice clouds occur over continents.(2)The average spatial and seasonal distributions of cloud types show three patterns: high clouds and most cumuliform clouds are concentrated in low-latitude locations and peak in summer;altostratus and nimbostratus are concentrated over and around continents and are less abundant in summer;stratocumulus and stratus are concentrated near the inner Arctic and peak during spring and autumn.(3) Regional averaged interannual frequencies of ice clouds and altostratus clouds significantly decrease, while those of water clouds, altocumulus, and cumulus clouds increase significantly.(4) Significant features of the linear trends of cloud frequencies are mainly located over ocean areas.(5) The monthly water cloud frequency anomalies are positively correlated with air temperature in most of the troposphere, while those for ice clouds are negatively correlated.(6) The decrease in altostratus clouds is associated with the weakening of the Arctic front due to Arctic warming, while increased water vapor transport into the Arctic and higher atmospheric instability lead to more cumulus and altocumulus clouds.

关键词： CloudSat and CALIPSO cloud type cloud phase temporal and spatial distribution interannual variation