Using satellites to complete spectrum monitoring tasks can effectively receive and process electromagnetic spectrum signals emitted by radiation sources.However,due to the shortage of satellite storage,computing and n...Using satellites to complete spectrum monitoring tasks can effectively receive and process electromagnetic spectrum signals emitted by radiation sources.However,due to the shortage of satellite storage,computing and network resources,the intersatellite coordination is weak,and with the massive growth of spectrum data,the traditional cloud computing mode cannot meet the requirements of electromagnetic spectrum monitoring in terms of real-time,bandwidth,and security.We apply edge computing technology and deep learning technology to the satellite.Aiming at the problems of distributed satellite management and control,we propose a space-based distributed electromagnetic spectrum monitoring intelligent connected cloud-edge collaborative architecture SpaceEdge.SpaceEdge applies edge computing and artificial intelligence technology to space-based spectrum monitoring.SpaceEdge deploys intelligent monitoring algorithms to edge nodes to form edge intelligent satellite,and uses the cloud to uniformly manage and control heterogeneous edge satellite and monitor satellite resources.In addition,SpaceEdge can also adjust edge intelligent spectrum monitoring applications as needed to achieve effective coordination of inter-satellite algorithms and data to achieve the purpose of collaborative monitoring.Finally,SpaceEdge was experimentally verified,and the results proved the feasibility of SpaceEdge and can improve the timeliness and autonomy of the distributed satellite’s coordinated signal monitoring.展开更多
Cloud storage and edge computing are utilized to address the storage and computational challenges arising from the exponential data growth in IoT.However,data privacy is potentially risky when data is outsourced to cl...Cloud storage and edge computing are utilized to address the storage and computational challenges arising from the exponential data growth in IoT.However,data privacy is potentially risky when data is outsourced to cloud servers or edge services.While data encryption ensures data confidentiality,it can impede data sharing and retrieval.Attribute-based searchable encryption(ABSE)is proposed as an effective technique for enhancing data security and privacy.Nevertheless,ABSE has its limitations,such as single attribute authorization failure,privacy leakage during the search process,and high decryption overhead.This paper presents a novel approach called the blockchain-assisted efficientmulti-authority attribute-based searchable encryption scheme(BEM-ABSE)for cloudedge collaboration scenarios to address these issues.BEM-ABSE leverages a consortium blockchain to replace the central authentication center for global public parameter management.It incorporates smart contracts to facilitate reliable and fair ciphertext keyword search and decryption result verification.To minimize the computing burden on resource-constrained devices,BEM-ABSE adopts an online/offline hybrid mechanism during the encryption process and a verifiable edge-assisted decryption mechanism.This ensures both low computation cost and reliable ciphertext.Security analysis conducted under the random oracle model demonstrates that BEM-ABSE is resistant to indistinguishable chosen keyword attacks(IND-CKA)and indistinguishable chosen plaintext attacks(INDCPA).Theoretical analysis and simulation results confirm that BEM-ABSE significantly improves computational efficiency compared to existing solutions.展开更多
Under solvothermal conditions,1,4‑naphthalenedicarboxylic acid(H_(2)ndc)and 9,9′‑dihexyl‑2,7‑di(pyridin‑4‑yl)fluorene(hfdp)reacted with Co^(2+)ions and Cd^(2+)ions to form two coordination polymers,[Co(hfdp)(ndc)(H2O...Under solvothermal conditions,1,4‑naphthalenedicarboxylic acid(H_(2)ndc)and 9,9′‑dihexyl‑2,7‑di(pyridin‑4‑yl)fluorene(hfdp)reacted with Co^(2+)ions and Cd^(2+)ions to form two coordination polymers,[Co(hfdp)(ndc)(H2O)]·DMA}n(1)and{[Cd(hfdp)(ndc)(H_(2)O)]·DMA}_(n)(2),respectively(DMA=N,N‑dimethylacetamide).Single‑crystal X‑ray diffraction analyses showed that both complexes 1 and 2 contain similar structures.Topological analysis indicates that complexes 1 and 2 have a{44·62}planar structure.In addition,both complexes reveal good thermal stability and fluorescence sensing performance.They exhibited good sensitivity and selectivity towards 2,4,6‑trinitrophenol(TNP)by fluorescent quenching.The limits of detection of 1 and 2 for TNP were 0.107 and 0.327μmol·L^(-1),respectively.CCDC:2475515,1;2475516,2.展开更多
In wind power transmission via modular multilevel converter based high voltage direct current(MMCHVDC)systems,under traditional control strategies,MMC-HVDCcannot provide inertia support to the receiving-end grid(REG)d...In wind power transmission via modular multilevel converter based high voltage direct current(MMCHVDC)systems,under traditional control strategies,MMC-HVDCcannot provide inertia support to the receiving-end grid(REG)during disturbances.Moreover,due to the frequency decoupling between the two ends of the MMCHVDC,the sending-end wind farm(SEWF)cannot obtain the frequency variation information of the REG to provide inertia response.Therefore,this paper proposes a novel coordinated source-network-storage inertia control strategy based on wind power transmission via MMC-HVDC system.First,the grid-side MMC station(GS-MMC)maps the frequency variations of the REG to direct current(DC)voltage variations through the frequency mapping control,and uses submodule capacitor energy to provide inertial power.Then,the wind farm-side MMC station(WF-MMC)restores the DC voltage variations to frequency variations through the frequency restoration control and power loss compensation,providing real-time frequency information for the wind farm.Finally,based on real-time frequency information,thewind farmutilizes the rotor kinetic energy and energy storage to provide fast and lasting power support through the wind-storage coordinated inertia control strategy.Meanwhile,when the wind turbines withdraw from the inertia response phase,the energy storage can increase the power output to compensate for the power deficit,preventing secondary frequency drops.Furthermore,this paper uses small-signal analysis to determine the appropriate values for the key parameters of the proposed control strategy.A simulation model of the wind power transmission via MMCHVDC system is built in MATLAB/Simulink environment to validate and evaluate the proposed method.The results show that the proposed coordinated control strategy can effectively improve the system inertia level and avoid the secondary frequency drop under the load sudden increase condition.展开更多
Four distinct coordination polymers(CPs)were successfully synthesized by altering solvent types and adjusting ligand concentrations,and their crystal structures were investigated.[Co(L)(FDCA)(H_(2)O)_(2)]·0.5H_(2...Four distinct coordination polymers(CPs)were successfully synthesized by altering solvent types and adjusting ligand concentrations,and their crystal structures were investigated.[Co(L)(FDCA)(H_(2)O)_(2)]·0.5H_(2)O(1)was synthesized as a 2D structure using Coas the metal source,methanol‑water(4∶6,V/V)as the solvent,and specific concentrations of 2,5‑furandicarboxylic acid(H_(2)FDCA)and 1,3,5‑triimidazole benzene(L).Adjusting to pure water and lowering the concentration of L yielded the 1D chain structure of[Co(HL)2(H_(2)O)_(2)](FDCA)_(2)·6H_(2)O(2).Using Cu(Ⅱ)as the metal source,methanol/water(9∶1,V/V)as the solvent,and specific concentrations of L and H2FDCA,the 1D chain structure of[Cu(L)(FDCA)(H_(2)O)]·2H_(2)O(3)was synthesized.Upon increasing the concentrations of L and H2FDCA,and switching the solvent to pure water,the 1D chain structure of[Cu(HL)_(2)(H_(2)O)_(2)](FDCA)_(2)·6H_(2)O(4)was obtained.This shows that changing the solvent and ligand concentrations can affect the structural changes of CPs.In addition,the solid‑state photoluminescence of CPs 1‑4 at room temperature was studied,and their morphological changes were observed via scanning electron microscopy.Density functional theory calculations revealed that the negative charge concentrates on the O and N atoms of the ligand,facilitating ligand‑metal ion coordination.CCDC:2403934,1;2403935,2;2403936,3;2403938,4.展开更多
Cooperative pursuit poses challenges across natural,social,and technical systems,particularly when decentralized,slow-speed pursuers attempt to capture a high-speed evader with limited observation.Most existing contri...Cooperative pursuit poses challenges across natural,social,and technical systems,particularly when decentralized,slow-speed pursuers attempt to capture a high-speed evader with limited observation.Most existing contributions place the focus on the greedy pursuit of the evader,overlooking potential collaborations among pursuers.To tackle this issue,a decisionmaking framework of multi-agent coordinated reciprocity formation pursuit(MACRFP)via deep reinforcement learning is introduced.This framework integrates the actor-critic algorithm with the coordinated reciprocity mechanism to enhance the capability of capturing a faster evader.Initially,a local perception model is created by utilizing a cellular network to simulate limitations caused by obstacles.Next,the formation coalition of pursuit is guided by the Cartesian Oval,enabling dispersed pursuers to create a siege against the faster evader.Furthermore,a coordinated reciprocity model based on the coordination graph and the attention-based graph neural networks is developed,addressing the global coordination problem by estimating a reciprocity coefficient to adjust agents'rewards.Numerical simulations demonstrate the emergence of cooperative behaviors in cooperative besiegement,target tracking,and intelligent interception during the pursuit,indicating that the proposed algorithm enhances the feasibility and effectiveness of capturing a fast-escaping target by integrating coordinated reciprocity and coalition formation.展开更多
Grid-Forming(GFM)converters are prone to fault-induced overcurrent and power angle instability during grid fault-induced voltage sags.To address this,this paper develops a multi-loop coordinated fault ridethrough(FRT)...Grid-Forming(GFM)converters are prone to fault-induced overcurrent and power angle instability during grid fault-induced voltage sags.To address this,this paper develops a multi-loop coordinated fault ridethrough(FRT)control strategy based on a power outer loop and voltage-current inner loops,aiming to enhance the stability and current-limiting capability of GFM converters during grid fault conditions.During voltage sags,the GFM converter’s voltage source behavior is maintained by dynamically adjusting the reactive power reference to provide voltage support,thereby effectively suppressing the steady-state component of the fault current.To address the active power imbalance induced by voltage sags,a dynamic active power reference correction method based on apparent power is designed to mitigate power angle oscillations and limit transient current.Moreover,an adaptive virtual impedance loop is implemented to enhance dynamic transient current-limiting performance during the fault initiation phase.This approach improves the responsiveness of the inner loop and ensures safe system operation under various fault severities.Under asymmetric fault conditions,a negative-sequence reactive current compensation strategy is incorporated to further suppress negative-sequence voltage and improve voltage symmetry.The proposed control scheme enables coordinated operation of multiple control objectives,including voltage support,current suppression,and power angle stability,across different fault scenarios.Finally,MATLAB/Simulink simulation results validate the effectiveness of the proposed strategy,showcasing its superior performance in current limiting and power angle stability,thereby significantly enhancing the system’s fault ride-through capability.展开更多
Prussian blue analogs(PBAs)are considered one of the excellent cathode materials for sodium-ion batteries due to their low cost and high theoretical specific capacity,especially sodium-rich iron-based PBAs(FeHCF)can p...Prussian blue analogs(PBAs)are considered one of the excellent cathode materials for sodium-ion batteries due to their low cost and high theoretical specific capacity,especially sodium-rich iron-based PBAs(FeHCF)can provide higher energy density.FeHCF has a poor charge/discharge platform stability at high voltages(FeC_(6)moiety),which is mainly affected by its coordination environment.In this research,Cu^(+)(six-coordinated),which is close to the ionic radius of Fe^(2+),was used for substitution,the FeC_(6)vacancies of FeHCF were reduced,and the coordination environment was optimized.The low Cu^(+)-substituted FeHCF(Cu^(+)0.625)has an optimal electrochemical performance at 8.5 mA/g with a reversible specific capacity of 142 mA h/g and FeC_(6)moiety contribution of more than 68 mA h/g,which is superior to that of unmodified and other Cu^(2+)-substituted FeHCFs.In situ tests demonstrate the reversible structural stability of the Cu^(+)0.625,supporting the stability of their high-voltage platform capacity.This Cu^(+)substitution strategy further enriches the approach to optimize the coordination environment of sodium-rich FeHCF.展开更多
Traffic at urban intersections frequently encounters unexpected obstructions,resulting in congestion due to uncooperative and priority-based driving behavior.This paper presents an optimal right-turn coordination syst...Traffic at urban intersections frequently encounters unexpected obstructions,resulting in congestion due to uncooperative and priority-based driving behavior.This paper presents an optimal right-turn coordination system for Connected and Automated Vehicles(CAVs)at single-lane intersections,particularly in the context of left-hand side driving on roads.The goal is to facilitate smooth right turns for certain vehicles without creating bottlenecks.We consider that all approaching vehicles share relevant information through vehicular communications.The Intersection Coordination Unit(ICU)processes this information and communicates the optimal crossing or turning times to the vehicles.The primary objective of this coordination is to minimize overall traffic delays,which also helps improve the fuel consumption of vehicles.By considering information from upcoming vehicles at the intersection,the coordination system solves an optimization problem to determine the best timing for executing right turns,ultimately minimizing the total delay for all vehicles.The proposed coordination system is evaluated at a typical urban intersection,and its performance is compared to traditional traffic systems.Numerical simulation results indicate that the proposed coordination system significantly enhances the average traffic speed and fuel consumption compared to the traditional traffic system in various scenarios.展开更多
Acceptorless dehydrogenative coupling of pyridinemethanol with ketones is one of the most reliable methodologies to access functionalized 1,8-naphthyridine derivatives.However,it is challenging to develop environmenta...Acceptorless dehydrogenative coupling of pyridinemethanol with ketones is one of the most reliable methodologies to access functionalized 1,8-naphthyridine derivatives.However,it is challenging to develop environmentally friendly catalytic systems,especially in constructing efficient and recyclable catalysts under water or solvent-free conditions.Here,we designed two novel coordination polymers Cd-CPs and Fe-CPs to investigate their catalytic performance in water.Gratifyingly,it was observed that Cd-CPs as a multifunctional catalyst was successfully applied to establish a universal pathway for direct fabrication of 1,8-naphthyridine derivatives under water conditions,while it was effective for the synthesis of1,3,5-triazines through acceptorless dehydrogenative coupling strategies.The features of broad substrate,high atom efficiency,and good catalyst reusability highlight the feasibility of this transformation.In additional,we demonstrated the spindle-like structures Fe-P,derived from the Fe-CPs via phosphorylation,which can be used as an efficient electrocatalyst for oxygen evolution reaction with good stability.This work provides two highly efficient non-noble metal catalysts for functionalized 1,8-naphthyridine derivatives production and oxygen evolution reaction,and opens a new avenue to further fabricate diverse metal catalysts with high catalytic performance in water.展开更多
The emergence of precision electronic devices and wearable electronic products urgently requires high-performance multifunctional electromagnetic wave(EMW)absorbers to meet the applicability and versatility in various...The emergence of precision electronic devices and wearable electronic products urgently requires high-performance multifunctional electromagnetic wave(EMW)absorbers to meet the applicability and versatility in various applications.Herein,a dual-network(DN)gel was successfully prepared using acrylamide and sodium lignosulphonate as the basic units by simple chemical cross-linking and physical cross-linking methods.Specifically,the hydrogel forms two types of cross-linking networks through metal coordination and hydrogen bonding.Benefiting from the combined effects of dipole polarization and conductivity loss,the gel achieves an effective absorption bandwidth(EAB)of 6.74 GHz at a thickness of only 1.89 mm,demonstrating excellent EMW absorption performance.In addition,this unique structural configuration endows the EMW absorber with multifunctional features,such as remarkable tensile strength,good environmental compatibility,ultraviolet(UV)resistance,and excellent adhesion.Integrating multiple functional features into the EMW gels displays a broad application prospect in a variety of application scenarios.This research reveals the significance of DN structure design in the electromagnetic wave absorption(EWA)performance of gel-based materials,providing a substantial foundation for the multifunctional design of gel-based absorbers.展开更多
Facing the economic challenges of significant frequency regulation wear and tear on thermal power units and short energy storage lifespan in thermal-energy storage combined systems participating in grid primary freque...Facing the economic challenges of significant frequency regulation wear and tear on thermal power units and short energy storage lifespan in thermal-energy storage combined systems participating in grid primary frequency regulation(PFR),this paper proposes a novel hybrid energy storage system(HESS)control strategy based on Newton-Raphson optimization algorithm(NRBO)-VMD and a fuzzy neural network(FNN)for PFR.In the primary power allocation stage,the high inertia and slow response of thermal power units prevent them from promptly responding to the high-frequency components of PFR signals,leading to increased mechanical stress.To address the distinct response characteristics of thermal units and HESS,an NRBO-VMD based decomposition method for PFR signals is proposed,enabling a flexible system response to grid frequency deviations.Within the HESS,an adaptive coordinated control strategy and a State of Charge(SOC)self-recovery strategy are introduced.These strategies autonomously adjust the virtual inertia and droop coefficients based on the depth of frequency regulation and the real-time SOC.Furthermore,a FNN is constructed to perform secondary refinement of the internal power distribution within the HESS.Finally,simulations under various operational conditions demonstrate that the proposed strategy effectively mitigates frequent power adjustments of the thermal unit during PFR,adaptively achieves optimal power decomposition and distribution,maintains the flywheel energy storage’s SOC within an optimal range,and ensures the long-term stable operation of the HESS.展开更多
Oxygen vacancy(Vo)engineering has been recognized as one of the most effective strategies for enhancing the photocatalytic CO_(2) conversion performance of metal oxides,as it can simultaneously facilitate photogenerat...Oxygen vacancy(Vo)engineering has been recognized as one of the most effective strategies for enhancing the photocatalytic CO_(2) conversion performance of metal oxides,as it can simultaneously facilitate photogenerated charge carrier separation efficiency and provide additional surface reaction sites.However,the wide application of Vo engineering in photocatalysis are limited by its poor stability,owing to the easy recovery of these vacancy defects by atmospheric oxygen.Herein,we develop an indium(In)doping strategy to regulate the coordination environment in CeO_(2) with abundant Vo(CeO_(2-x)),thereby enhance its stability during photocatalytic CO_(2) conversion.Confirmed by positron annihilation lifetime spectroscopy(PALS),In dopants combine with Vo by substituting for part of Ce^(4+),forming In^(3+)-Vo complexes that effectively inhibit the formation of unstable va-cancy clusters.Such In^(3+)-Vo complexes can also reduce the energy required for formation of the CO products.Therefore,the optimized In-doped CeO_(2-x) exhibits excellent photocatalytic CO_(2) conversion performance,with a CO yield of 301.6μmol⋅g^(-1) after 5 h of light irradiation,and maintain high activity after four cycles of experiments.Comprehensive experimental and theoretical studies indicate that the introduction of In doping not only significantly improves the stability of Vo in CeO_(2-x),but also reconstruct the reaction kinetics of the CO_(2) conversion by forming In^(3+)-Vo complexes thus facilitating the overall reaction.展开更多
The precise tuning of magnetic nanoparticle size and magnetic domains,thereby shaping magnetic properties.However,the dynamic evolution mechanisms of magnetic domain configurations in relation to electromagnetic(EM)at...The precise tuning of magnetic nanoparticle size and magnetic domains,thereby shaping magnetic properties.However,the dynamic evolution mechanisms of magnetic domain configurations in relation to electromagnetic(EM)attenuation behavior remain poorly understood.To address this gap,a thermodynamically controlled periodic coordination strategy is proposed to achieve precise modulation of magnetic nanoparticle spacing.This approach unveils the evolution of magnetic domain configurations,progressing from individual to coupled and ultimately to crosslinked domain configurations.A unique magnetic coupling phenomenon surpasses the Snoek limit in low-frequency range,which is observed through micromagnetic simulation.The crosslinked magnetic configuration achieves effective low-frequency EM wave absorption at 3.68 GHz,encompassing nearly the entire C-band.This exceptional magnetic interaction significantly enhances radar camouflage and thermal insulation properties.Additionally,a robust gradient metamaterial design extends coverage across the full band(2–40 GHz),effectively mitigating the impact of EM pollution on human health and environment.This comprehensive study elucidates the evolution mechanisms of magnetic domain configurations,addresses gaps in dynamic magnetic modulation,and provides novel insights for the development of high-performance,low-frequency EM wave absorption materials.展开更多
The development of human settlements(HS)in coastal cities is an integral component and a vital pathway toward building a strong marine power.It is also an essential requirement for achieving the coordinated developmen...The development of human settlements(HS)in coastal cities is an integral component and a vital pathway toward building a strong marine power.It is also an essential requirement for achieving the coordinated development of HS systems in these cities.In this study,we constructed an indicator system to analyze the coupling coordination degree(CCD)of HS systems in coastal cities in the Bohai Rim region of China(CCBRR).This study is based on five systems and employs methods such as the entropy weight method,CCD model,spatial trend surface analysis,and geographic detector to examine comprehensively the spatial and temporal patterns of CCD in 17 CCBRR during the period 2011–2022,as well as to explore their influencing factors.The findings are as follows:(1)Temporally,the CCD is high and exhibits a slow increasing trend,with distinct stage characteristics.(2)Spatially,the distribution of CCD reveals a“one core,many strengths”structural pattern.(3)Moreover,socioeconomic factors are the dominant force driving the CCD of the internal HS systems in the CCBRR.(4)Finally,we constructed a coupling coordination driving mechanism for HS in the CCBRR with the aim of providing scientific references and path choices for the high-quality and coordinated development of the CCBRR along with the implementation of the new quality productive forces regionalization.展开更多
Accurate and real-time traffic-sign detection is a cornerstone of Advanced Driver-Assistance Systems(ADAS)and autonomous vehicles.However,existing one-stage detectors miss distant signs,and two-stage pipelines are imp...Accurate and real-time traffic-sign detection is a cornerstone of Advanced Driver-Assistance Systems(ADAS)and autonomous vehicles.However,existing one-stage detectors miss distant signs,and two-stage pipelines are impractical for embedded deployment.To address this issue,we present YOLO-SMM,a lightweight two-stage framework.This framework is designed to augment the YOLOv8 baseline with three targeted modules.(1)SlimNeck replaces PAN/FPN with a CSP-OSA/GSConv fusion block,reducing parameters and FLOPs without compromising multi-scale detail.(2)The MCA model introduces row-and column-aware weights to selectively amplify small sign regions in cluttered scenes.(3)MPDIoU augments CIoU loss with a corner-distance term,supplying stable gradients for sub-20-pixel boxes and tightening localization.An evaluation of YOLO-SMMon the German Traffic Sign Recognition Benchmark(GTSRB)revealed that it attained 96.3% mAP50 and 93.1% mAP50-90 at a rate of 90.6 frames per second(FPS).This represents an improvement of+1.0% over previous performance benchmarks.Them APat 64×64 resolution was found to be 50% of the maximum attainable value,with an FPS of+8.3 when compared to YOLOv8.This result indicates superior performance in terms of accuracy and speed compared to YOLOv7,YOLOv5,RetinaNet,EfficientDet,and Faster R-CNN,all of which were operated under equivalent conditions.展开更多
Dear Editor,This letter addresses the challenge of achieving robust global coordination in multi-agent systems(MASs)subject to heterogeneous actuator saturation and additive input disturbances.We develop a novel distr...Dear Editor,This letter addresses the challenge of achieving robust global coordination in multi-agent systems(MASs)subject to heterogeneous actuator saturation and additive input disturbances.We develop a novel distributed control framework that strategically integrates a redesigned saturation function to handle the nonlinear actuator constraint and a high-gain feedback mechanism for effective disturbance rejection.展开更多
Zeolites with ordered porous structure of molecular size are widely employed as commercial adsorbents and catalysts.On the other hand,the zeolite matrix is regarded as an ideal scaffold for hosting coordinatively unsa...Zeolites with ordered porous structure of molecular size are widely employed as commercial adsorbents and catalysts.On the other hand,the zeolite matrix is regarded as an ideal scaffold for hosting coordinatively unsaturated sites.Remarkable achievements have been made dealing with the construction,characterization and catalytic applications of coordinatively unsaturated sites in zeolite matrix.Herein,a literature overview of recent progresses on this important topic is presented from the specific view of coordination chemistry.Different strategies to construction coordinatively unsaturated sites in zeolite matrix,in zeolite framework or extraframework positions,are first introduced and their characteristics are compared.Then,spectroscopic techniques to determine the existing states of cation sites and their transformations in zeolite matrix are discussed.In the last section,the catalytic applications of coordinatively unsaturated sites in zeolite matrix for various important chemical transformations are summarized.展开更多
In this paper,we propose a novel fuzzy matching data sharing scheme named FADS for cloudedge communications.FADS allows users to specify their access policies,and enables receivers to obtain the data transmitted by th...In this paper,we propose a novel fuzzy matching data sharing scheme named FADS for cloudedge communications.FADS allows users to specify their access policies,and enables receivers to obtain the data transmitted by the senders if and only if the two sides meet their defined certain policies simultaneously.Specifically,we first formalize the definition and security models of fuzzy matching data sharing in cloud-edge environments.Then,we construct a concrete instantiation by pairing-based cryptosystem and the privacy-preserving set intersection on attribute sets from both sides to construct a concurrent matching over the policies.If the matching succeeds,the data can be decrypted.Otherwise,nothing will be revealed.In addition,FADS allows users to dynamically specify the policy for each time,which is an urgent demand in practice.A thorough security analysis demonstrates that FADS is of provable security under indistinguishable chosen ciphertext attack(IND-CCA)in random oracle model against probabilistic polynomial-time(PPT)adversary,and the desirable security properties of privacy and authenticity are achieved.Extensive experiments provide evidence that FADS is with acceptable efficiency.展开更多
Nowadays,the rapid development of edge computing has driven an increasing number of deep learning applications deployed at the edge of the network,such as pedestrian and vehicle detection,to provide efficient intellig...Nowadays,the rapid development of edge computing has driven an increasing number of deep learning applications deployed at the edge of the network,such as pedestrian and vehicle detection,to provide efficient intelligent services to mobile users.However,as the accuracy requirements continue to increase,the components of deep learning models for pedestrian and vehicle detection,such as YOLOv4,become more sophisticated and the computing resources required for model training are increasing dramatically,which in turn leads to significant challenges in achieving effective deployment on resource-constrained edge devices while ensuring the high accuracy performance.For addressing this challenge,a cloud-edge collaboration-based pedestrian and vehicle detection framework is proposed in this paper,which enables sufficient training of models by utilizing the abundant computing resources in the cloud,and then deploying the well-trained models on edge devices,thus reducing the computing resource requirements for model training on edge devices.Furthermore,to reduce the size of the model deployed on edge devices,an automatic pruning method combines the convolution layer and BN layer is proposed to compress the pedestrian and vehicle detection model size.Experimental results show that the framework proposed in this paper is able to deploy the pruned model on a real edge device,Jetson TX2,with 6.72 times higher FPS.Meanwhile,the channel pruning reduces the volume and the number of parameters to 96.77%for the model,and the computing amount is reduced to 81.37%.展开更多
文摘Using satellites to complete spectrum monitoring tasks can effectively receive and process electromagnetic spectrum signals emitted by radiation sources.However,due to the shortage of satellite storage,computing and network resources,the intersatellite coordination is weak,and with the massive growth of spectrum data,the traditional cloud computing mode cannot meet the requirements of electromagnetic spectrum monitoring in terms of real-time,bandwidth,and security.We apply edge computing technology and deep learning technology to the satellite.Aiming at the problems of distributed satellite management and control,we propose a space-based distributed electromagnetic spectrum monitoring intelligent connected cloud-edge collaborative architecture SpaceEdge.SpaceEdge applies edge computing and artificial intelligence technology to space-based spectrum monitoring.SpaceEdge deploys intelligent monitoring algorithms to edge nodes to form edge intelligent satellite,and uses the cloud to uniformly manage and control heterogeneous edge satellite and monitor satellite resources.In addition,SpaceEdge can also adjust edge intelligent spectrum monitoring applications as needed to achieve effective coordination of inter-satellite algorithms and data to achieve the purpose of collaborative monitoring.Finally,SpaceEdge was experimentally verified,and the results proved the feasibility of SpaceEdge and can improve the timeliness and autonomy of the distributed satellite’s coordinated signal monitoring.
基金supported by the National Natural Science Foundation of China(Nos.62162018,61972412)the Natural Science Foundation of Guangxi(No.2019GXNSFGA245004)+1 种基金the Guilin Science and Technology Project(20210226-1)the Innovation Project of Guangxi Graduate Education(No.YCSW2022296).
文摘Cloud storage and edge computing are utilized to address the storage and computational challenges arising from the exponential data growth in IoT.However,data privacy is potentially risky when data is outsourced to cloud servers or edge services.While data encryption ensures data confidentiality,it can impede data sharing and retrieval.Attribute-based searchable encryption(ABSE)is proposed as an effective technique for enhancing data security and privacy.Nevertheless,ABSE has its limitations,such as single attribute authorization failure,privacy leakage during the search process,and high decryption overhead.This paper presents a novel approach called the blockchain-assisted efficientmulti-authority attribute-based searchable encryption scheme(BEM-ABSE)for cloudedge collaboration scenarios to address these issues.BEM-ABSE leverages a consortium blockchain to replace the central authentication center for global public parameter management.It incorporates smart contracts to facilitate reliable and fair ciphertext keyword search and decryption result verification.To minimize the computing burden on resource-constrained devices,BEM-ABSE adopts an online/offline hybrid mechanism during the encryption process and a verifiable edge-assisted decryption mechanism.This ensures both low computation cost and reliable ciphertext.Security analysis conducted under the random oracle model demonstrates that BEM-ABSE is resistant to indistinguishable chosen keyword attacks(IND-CKA)and indistinguishable chosen plaintext attacks(INDCPA).Theoretical analysis and simulation results confirm that BEM-ABSE significantly improves computational efficiency compared to existing solutions.
文摘Under solvothermal conditions,1,4‑naphthalenedicarboxylic acid(H_(2)ndc)and 9,9′‑dihexyl‑2,7‑di(pyridin‑4‑yl)fluorene(hfdp)reacted with Co^(2+)ions and Cd^(2+)ions to form two coordination polymers,[Co(hfdp)(ndc)(H2O)]·DMA}n(1)and{[Cd(hfdp)(ndc)(H_(2)O)]·DMA}_(n)(2),respectively(DMA=N,N‑dimethylacetamide).Single‑crystal X‑ray diffraction analyses showed that both complexes 1 and 2 contain similar structures.Topological analysis indicates that complexes 1 and 2 have a{44·62}planar structure.In addition,both complexes reveal good thermal stability and fluorescence sensing performance.They exhibited good sensitivity and selectivity towards 2,4,6‑trinitrophenol(TNP)by fluorescent quenching.The limits of detection of 1 and 2 for TNP were 0.107 and 0.327μmol·L^(-1),respectively.CCDC:2475515,1;2475516,2.
基金funded by State Grid Corporation of China Central Branch Technology Project(52140024000C).
文摘In wind power transmission via modular multilevel converter based high voltage direct current(MMCHVDC)systems,under traditional control strategies,MMC-HVDCcannot provide inertia support to the receiving-end grid(REG)during disturbances.Moreover,due to the frequency decoupling between the two ends of the MMCHVDC,the sending-end wind farm(SEWF)cannot obtain the frequency variation information of the REG to provide inertia response.Therefore,this paper proposes a novel coordinated source-network-storage inertia control strategy based on wind power transmission via MMC-HVDC system.First,the grid-side MMC station(GS-MMC)maps the frequency variations of the REG to direct current(DC)voltage variations through the frequency mapping control,and uses submodule capacitor energy to provide inertial power.Then,the wind farm-side MMC station(WF-MMC)restores the DC voltage variations to frequency variations through the frequency restoration control and power loss compensation,providing real-time frequency information for the wind farm.Finally,based on real-time frequency information,thewind farmutilizes the rotor kinetic energy and energy storage to provide fast and lasting power support through the wind-storage coordinated inertia control strategy.Meanwhile,when the wind turbines withdraw from the inertia response phase,the energy storage can increase the power output to compensate for the power deficit,preventing secondary frequency drops.Furthermore,this paper uses small-signal analysis to determine the appropriate values for the key parameters of the proposed control strategy.A simulation model of the wind power transmission via MMCHVDC system is built in MATLAB/Simulink environment to validate and evaluate the proposed method.The results show that the proposed coordinated control strategy can effectively improve the system inertia level and avoid the secondary frequency drop under the load sudden increase condition.
文摘Four distinct coordination polymers(CPs)were successfully synthesized by altering solvent types and adjusting ligand concentrations,and their crystal structures were investigated.[Co(L)(FDCA)(H_(2)O)_(2)]·0.5H_(2)O(1)was synthesized as a 2D structure using Coas the metal source,methanol‑water(4∶6,V/V)as the solvent,and specific concentrations of 2,5‑furandicarboxylic acid(H_(2)FDCA)and 1,3,5‑triimidazole benzene(L).Adjusting to pure water and lowering the concentration of L yielded the 1D chain structure of[Co(HL)2(H_(2)O)_(2)](FDCA)_(2)·6H_(2)O(2).Using Cu(Ⅱ)as the metal source,methanol/water(9∶1,V/V)as the solvent,and specific concentrations of L and H2FDCA,the 1D chain structure of[Cu(L)(FDCA)(H_(2)O)]·2H_(2)O(3)was synthesized.Upon increasing the concentrations of L and H2FDCA,and switching the solvent to pure water,the 1D chain structure of[Cu(HL)_(2)(H_(2)O)_(2)](FDCA)_(2)·6H_(2)O(4)was obtained.This shows that changing the solvent and ligand concentrations can affect the structural changes of CPs.In addition,the solid‑state photoluminescence of CPs 1‑4 at room temperature was studied,and their morphological changes were observed via scanning electron microscopy.Density functional theory calculations revealed that the negative charge concentrates on the O and N atoms of the ligand,facilitating ligand‑metal ion coordination.CCDC:2403934,1;2403935,2;2403936,3;2403938,4.
基金supported by the National Natural Science Foundation of China(72371052,71871042)。
文摘Cooperative pursuit poses challenges across natural,social,and technical systems,particularly when decentralized,slow-speed pursuers attempt to capture a high-speed evader with limited observation.Most existing contributions place the focus on the greedy pursuit of the evader,overlooking potential collaborations among pursuers.To tackle this issue,a decisionmaking framework of multi-agent coordinated reciprocity formation pursuit(MACRFP)via deep reinforcement learning is introduced.This framework integrates the actor-critic algorithm with the coordinated reciprocity mechanism to enhance the capability of capturing a faster evader.Initially,a local perception model is created by utilizing a cellular network to simulate limitations caused by obstacles.Next,the formation coalition of pursuit is guided by the Cartesian Oval,enabling dispersed pursuers to create a siege against the faster evader.Furthermore,a coordinated reciprocity model based on the coordination graph and the attention-based graph neural networks is developed,addressing the global coordination problem by estimating a reciprocity coefficient to adjust agents'rewards.Numerical simulations demonstrate the emergence of cooperative behaviors in cooperative besiegement,target tracking,and intelligent interception during the pursuit,indicating that the proposed algorithm enhances the feasibility and effectiveness of capturing a fast-escaping target by integrating coordinated reciprocity and coalition formation.
文摘Grid-Forming(GFM)converters are prone to fault-induced overcurrent and power angle instability during grid fault-induced voltage sags.To address this,this paper develops a multi-loop coordinated fault ridethrough(FRT)control strategy based on a power outer loop and voltage-current inner loops,aiming to enhance the stability and current-limiting capability of GFM converters during grid fault conditions.During voltage sags,the GFM converter’s voltage source behavior is maintained by dynamically adjusting the reactive power reference to provide voltage support,thereby effectively suppressing the steady-state component of the fault current.To address the active power imbalance induced by voltage sags,a dynamic active power reference correction method based on apparent power is designed to mitigate power angle oscillations and limit transient current.Moreover,an adaptive virtual impedance loop is implemented to enhance dynamic transient current-limiting performance during the fault initiation phase.This approach improves the responsiveness of the inner loop and ensures safe system operation under various fault severities.Under asymmetric fault conditions,a negative-sequence reactive current compensation strategy is incorporated to further suppress negative-sequence voltage and improve voltage symmetry.The proposed control scheme enables coordinated operation of multiple control objectives,including voltage support,current suppression,and power angle stability,across different fault scenarios.Finally,MATLAB/Simulink simulation results validate the effectiveness of the proposed strategy,showcasing its superior performance in current limiting and power angle stability,thereby significantly enhancing the system’s fault ride-through capability.
基金supported by the Key Talent Project of Gansu Province(2025RCXM017)the National Natural Science Foundation of China(52261040)+2 种基金the Postgraduate Innovation Star Program of Gansu Province(2025CXZX-476)the Major Science and Technology Project of Gansu Province(22ZD6GA008)the Innovation Driven Assistance Engineering Project of Gansu Association for Science and Technology(GXH20250325-5).
文摘Prussian blue analogs(PBAs)are considered one of the excellent cathode materials for sodium-ion batteries due to their low cost and high theoretical specific capacity,especially sodium-rich iron-based PBAs(FeHCF)can provide higher energy density.FeHCF has a poor charge/discharge platform stability at high voltages(FeC_(6)moiety),which is mainly affected by its coordination environment.In this research,Cu^(+)(six-coordinated),which is close to the ionic radius of Fe^(2+),was used for substitution,the FeC_(6)vacancies of FeHCF were reduced,and the coordination environment was optimized.The low Cu^(+)-substituted FeHCF(Cu^(+)0.625)has an optimal electrochemical performance at 8.5 mA/g with a reversible specific capacity of 142 mA h/g and FeC_(6)moiety contribution of more than 68 mA h/g,which is superior to that of unmodified and other Cu^(2+)-substituted FeHCFs.In situ tests demonstrate the reversible structural stability of the Cu^(+)0.625,supporting the stability of their high-voltage platform capacity.This Cu^(+)substitution strategy further enriches the approach to optimize the coordination environment of sodium-rich FeHCF.
基金supported by the Japan Society for the Promotion of Science(JSPS)Grants-in-Aid for Scientific Research(C)23K03898.
文摘Traffic at urban intersections frequently encounters unexpected obstructions,resulting in congestion due to uncooperative and priority-based driving behavior.This paper presents an optimal right-turn coordination system for Connected and Automated Vehicles(CAVs)at single-lane intersections,particularly in the context of left-hand side driving on roads.The goal is to facilitate smooth right turns for certain vehicles without creating bottlenecks.We consider that all approaching vehicles share relevant information through vehicular communications.The Intersection Coordination Unit(ICU)processes this information and communicates the optimal crossing or turning times to the vehicles.The primary objective of this coordination is to minimize overall traffic delays,which also helps improve the fuel consumption of vehicles.By considering information from upcoming vehicles at the intersection,the coordination system solves an optimization problem to determine the best timing for executing right turns,ultimately minimizing the total delay for all vehicles.The proposed coordination system is evaluated at a typical urban intersection,and its performance is compared to traditional traffic systems.Numerical simulation results indicate that the proposed coordination system significantly enhances the average traffic speed and fuel consumption compared to the traditional traffic system in various scenarios.
基金financial support of this work by the National Natural Science Foundation of China(No.21861039)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX24_2530)the Fundamental Research Funds for the Central Universities。
文摘Acceptorless dehydrogenative coupling of pyridinemethanol with ketones is one of the most reliable methodologies to access functionalized 1,8-naphthyridine derivatives.However,it is challenging to develop environmentally friendly catalytic systems,especially in constructing efficient and recyclable catalysts under water or solvent-free conditions.Here,we designed two novel coordination polymers Cd-CPs and Fe-CPs to investigate their catalytic performance in water.Gratifyingly,it was observed that Cd-CPs as a multifunctional catalyst was successfully applied to establish a universal pathway for direct fabrication of 1,8-naphthyridine derivatives under water conditions,while it was effective for the synthesis of1,3,5-triazines through acceptorless dehydrogenative coupling strategies.The features of broad substrate,high atom efficiency,and good catalyst reusability highlight the feasibility of this transformation.In additional,we demonstrated the spindle-like structures Fe-P,derived from the Fe-CPs via phosphorylation,which can be used as an efficient electrocatalyst for oxygen evolution reaction with good stability.This work provides two highly efficient non-noble metal catalysts for functionalized 1,8-naphthyridine derivatives production and oxygen evolution reaction,and opens a new avenue to further fabricate diverse metal catalysts with high catalytic performance in water.
基金supported by the National Natural Science Foundation of China(Nos.52231007,51872238,52074227,and 21806129)the Fundamental Research Funds for the Central Universities(Nos.3102018zy045,3102019AX11,and 5000220455)the Natural Science Basic Research Plan in Shaanxi Province of China(Nos.2017JQ5116 and 2020JM-118).
文摘The emergence of precision electronic devices and wearable electronic products urgently requires high-performance multifunctional electromagnetic wave(EMW)absorbers to meet the applicability and versatility in various applications.Herein,a dual-network(DN)gel was successfully prepared using acrylamide and sodium lignosulphonate as the basic units by simple chemical cross-linking and physical cross-linking methods.Specifically,the hydrogel forms two types of cross-linking networks through metal coordination and hydrogen bonding.Benefiting from the combined effects of dipole polarization and conductivity loss,the gel achieves an effective absorption bandwidth(EAB)of 6.74 GHz at a thickness of only 1.89 mm,demonstrating excellent EMW absorption performance.In addition,this unique structural configuration endows the EMW absorber with multifunctional features,such as remarkable tensile strength,good environmental compatibility,ultraviolet(UV)resistance,and excellent adhesion.Integrating multiple functional features into the EMW gels displays a broad application prospect in a variety of application scenarios.This research reveals the significance of DN structure design in the electromagnetic wave absorption(EWA)performance of gel-based materials,providing a substantial foundation for the multifunctional design of gel-based absorbers.
基金supported by the Lanzhou Science and Technology Plan Project(XM1753694781389).
文摘Facing the economic challenges of significant frequency regulation wear and tear on thermal power units and short energy storage lifespan in thermal-energy storage combined systems participating in grid primary frequency regulation(PFR),this paper proposes a novel hybrid energy storage system(HESS)control strategy based on Newton-Raphson optimization algorithm(NRBO)-VMD and a fuzzy neural network(FNN)for PFR.In the primary power allocation stage,the high inertia and slow response of thermal power units prevent them from promptly responding to the high-frequency components of PFR signals,leading to increased mechanical stress.To address the distinct response characteristics of thermal units and HESS,an NRBO-VMD based decomposition method for PFR signals is proposed,enabling a flexible system response to grid frequency deviations.Within the HESS,an adaptive coordinated control strategy and a State of Charge(SOC)self-recovery strategy are introduced.These strategies autonomously adjust the virtual inertia and droop coefficients based on the depth of frequency regulation and the real-time SOC.Furthermore,a FNN is constructed to perform secondary refinement of the internal power distribution within the HESS.Finally,simulations under various operational conditions demonstrate that the proposed strategy effectively mitigates frequent power adjustments of the thermal unit during PFR,adaptively achieves optimal power decomposition and distribution,maintains the flywheel energy storage’s SOC within an optimal range,and ensures the long-term stable operation of the HESS.
基金supported by the National Natural Science Foundation of China(No.22202152)Tianjin Municipal Science and Technology Bureau(No.24JCQNJC00990)Cangzhou Institute of Tiangong University(No.TGCYY-F-0304).
文摘Oxygen vacancy(Vo)engineering has been recognized as one of the most effective strategies for enhancing the photocatalytic CO_(2) conversion performance of metal oxides,as it can simultaneously facilitate photogenerated charge carrier separation efficiency and provide additional surface reaction sites.However,the wide application of Vo engineering in photocatalysis are limited by its poor stability,owing to the easy recovery of these vacancy defects by atmospheric oxygen.Herein,we develop an indium(In)doping strategy to regulate the coordination environment in CeO_(2) with abundant Vo(CeO_(2-x)),thereby enhance its stability during photocatalytic CO_(2) conversion.Confirmed by positron annihilation lifetime spectroscopy(PALS),In dopants combine with Vo by substituting for part of Ce^(4+),forming In^(3+)-Vo complexes that effectively inhibit the formation of unstable va-cancy clusters.Such In^(3+)-Vo complexes can also reduce the energy required for formation of the CO products.Therefore,the optimized In-doped CeO_(2-x) exhibits excellent photocatalytic CO_(2) conversion performance,with a CO yield of 301.6μmol⋅g^(-1) after 5 h of light irradiation,and maintain high activity after four cycles of experiments.Comprehensive experimental and theoretical studies indicate that the introduction of In doping not only significantly improves the stability of Vo in CeO_(2-x),but also reconstruct the reaction kinetics of the CO_(2) conversion by forming In^(3+)-Vo complexes thus facilitating the overall reaction.
基金supported by the National Natural Science Foundation of China(22265021,52231007,and 12327804)the Aeronautical Science Foundation of China(2020Z056056003)Jiangxi Provincial Natural Science Foundation(20232BAB212004).
文摘The precise tuning of magnetic nanoparticle size and magnetic domains,thereby shaping magnetic properties.However,the dynamic evolution mechanisms of magnetic domain configurations in relation to electromagnetic(EM)attenuation behavior remain poorly understood.To address this gap,a thermodynamically controlled periodic coordination strategy is proposed to achieve precise modulation of magnetic nanoparticle spacing.This approach unveils the evolution of magnetic domain configurations,progressing from individual to coupled and ultimately to crosslinked domain configurations.A unique magnetic coupling phenomenon surpasses the Snoek limit in low-frequency range,which is observed through micromagnetic simulation.The crosslinked magnetic configuration achieves effective low-frequency EM wave absorption at 3.68 GHz,encompassing nearly the entire C-band.This exceptional magnetic interaction significantly enhances radar camouflage and thermal insulation properties.Additionally,a robust gradient metamaterial design extends coverage across the full band(2–40 GHz),effectively mitigating the impact of EM pollution on human health and environment.This comprehensive study elucidates the evolution mechanisms of magnetic domain configurations,addresses gaps in dynamic magnetic modulation,and provides novel insights for the development of high-performance,low-frequency EM wave absorption materials.
基金National Natural Science Foundation of China,No.42201221,No.42471246Liaoning Province Natural Science Foundation Project,No.2023-MS-254+1 种基金Liaoning Province Social Science Planning Fund Project,No.L22CJY016Dalian Federation of Social Sciences,No.2022dlskzd037。
文摘The development of human settlements(HS)in coastal cities is an integral component and a vital pathway toward building a strong marine power.It is also an essential requirement for achieving the coordinated development of HS systems in these cities.In this study,we constructed an indicator system to analyze the coupling coordination degree(CCD)of HS systems in coastal cities in the Bohai Rim region of China(CCBRR).This study is based on five systems and employs methods such as the entropy weight method,CCD model,spatial trend surface analysis,and geographic detector to examine comprehensively the spatial and temporal patterns of CCD in 17 CCBRR during the period 2011–2022,as well as to explore their influencing factors.The findings are as follows:(1)Temporally,the CCD is high and exhibits a slow increasing trend,with distinct stage characteristics.(2)Spatially,the distribution of CCD reveals a“one core,many strengths”structural pattern.(3)Moreover,socioeconomic factors are the dominant force driving the CCD of the internal HS systems in the CCBRR.(4)Finally,we constructed a coupling coordination driving mechanism for HS in the CCBRR with the aim of providing scientific references and path choices for the high-quality and coordinated development of the CCBRR along with the implementation of the new quality productive forces regionalization.
基金supported by University of Malaya and Ministry of High Education-Malaysia via Fundamental Research Grant Scheme No.FRGS/1/2023/TK10/UM/02/3.
文摘Accurate and real-time traffic-sign detection is a cornerstone of Advanced Driver-Assistance Systems(ADAS)and autonomous vehicles.However,existing one-stage detectors miss distant signs,and two-stage pipelines are impractical for embedded deployment.To address this issue,we present YOLO-SMM,a lightweight two-stage framework.This framework is designed to augment the YOLOv8 baseline with three targeted modules.(1)SlimNeck replaces PAN/FPN with a CSP-OSA/GSConv fusion block,reducing parameters and FLOPs without compromising multi-scale detail.(2)The MCA model introduces row-and column-aware weights to selectively amplify small sign regions in cluttered scenes.(3)MPDIoU augments CIoU loss with a corner-distance term,supplying stable gradients for sub-20-pixel boxes and tightening localization.An evaluation of YOLO-SMMon the German Traffic Sign Recognition Benchmark(GTSRB)revealed that it attained 96.3% mAP50 and 93.1% mAP50-90 at a rate of 90.6 frames per second(FPS).This represents an improvement of+1.0% over previous performance benchmarks.Them APat 64×64 resolution was found to be 50% of the maximum attainable value,with an FPS of+8.3 when compared to YOLOv8.This result indicates superior performance in terms of accuracy and speed compared to YOLOv7,YOLOv5,RetinaNet,EfficientDet,and Faster R-CNN,all of which were operated under equivalent conditions.
基金supported in part by the National Natural Science Foundation of China(62522313,62473207,U25A20301)the Fundamental Research Funds for the Central Universities(2024SMECP03)。
文摘Dear Editor,This letter addresses the challenge of achieving robust global coordination in multi-agent systems(MASs)subject to heterogeneous actuator saturation and additive input disturbances.We develop a novel distributed control framework that strategically integrates a redesigned saturation function to handle the nonlinear actuator constraint and a high-gain feedback mechanism for effective disturbance rejection.
基金supported by the National Natural Science Fundation of China(21722303,21421001)the Municipal Natural Science Fund of Tianjin(18JCJQJC47400,18JCZDJC37400)111 Project(B12015,B18030)~~
文摘Zeolites with ordered porous structure of molecular size are widely employed as commercial adsorbents and catalysts.On the other hand,the zeolite matrix is regarded as an ideal scaffold for hosting coordinatively unsaturated sites.Remarkable achievements have been made dealing with the construction,characterization and catalytic applications of coordinatively unsaturated sites in zeolite matrix.Herein,a literature overview of recent progresses on this important topic is presented from the specific view of coordination chemistry.Different strategies to construction coordinatively unsaturated sites in zeolite matrix,in zeolite framework or extraframework positions,are first introduced and their characteristics are compared.Then,spectroscopic techniques to determine the existing states of cation sites and their transformations in zeolite matrix are discussed.In the last section,the catalytic applications of coordinatively unsaturated sites in zeolite matrix for various important chemical transformations are summarized.
基金supported by the China Postdoctoral Science Foundation (Grant Nos. 2021TQ0042, 2021M700435, 2021TQ0041)the National Natural Science Foundation of China (Grant No. 62102027)the Shandong Provincial Key Research and Development Program (2021CXGC010106)
文摘In this paper,we propose a novel fuzzy matching data sharing scheme named FADS for cloudedge communications.FADS allows users to specify their access policies,and enables receivers to obtain the data transmitted by the senders if and only if the two sides meet their defined certain policies simultaneously.Specifically,we first formalize the definition and security models of fuzzy matching data sharing in cloud-edge environments.Then,we construct a concrete instantiation by pairing-based cryptosystem and the privacy-preserving set intersection on attribute sets from both sides to construct a concurrent matching over the policies.If the matching succeeds,the data can be decrypted.Otherwise,nothing will be revealed.In addition,FADS allows users to dynamically specify the policy for each time,which is an urgent demand in practice.A thorough security analysis demonstrates that FADS is of provable security under indistinguishable chosen ciphertext attack(IND-CCA)in random oracle model against probabilistic polynomial-time(PPT)adversary,and the desirable security properties of privacy and authenticity are achieved.Extensive experiments provide evidence that FADS is with acceptable efficiency.
基金supported by Key-Area Research and Development Program of Guangdong Province(2021B0101420002)the Major Key Project of PCL(PCL2021A09)+3 种基金National Natural Science Foundation of China(62072187)Guangdong Major Project of Basic and Applied Basic Research(2019B030302002)Guangdong Marine Economic Development Special Fund Project(GDNRC[2022]17)Guangzhou Development Zone Science and Technology(2021GH10,2020GH10).
文摘Nowadays,the rapid development of edge computing has driven an increasing number of deep learning applications deployed at the edge of the network,such as pedestrian and vehicle detection,to provide efficient intelligent services to mobile users.However,as the accuracy requirements continue to increase,the components of deep learning models for pedestrian and vehicle detection,such as YOLOv4,become more sophisticated and the computing resources required for model training are increasing dramatically,which in turn leads to significant challenges in achieving effective deployment on resource-constrained edge devices while ensuring the high accuracy performance.For addressing this challenge,a cloud-edge collaboration-based pedestrian and vehicle detection framework is proposed in this paper,which enables sufficient training of models by utilizing the abundant computing resources in the cloud,and then deploying the well-trained models on edge devices,thus reducing the computing resource requirements for model training on edge devices.Furthermore,to reduce the size of the model deployed on edge devices,an automatic pruning method combines the convolution layer and BN layer is proposed to compress the pedestrian and vehicle detection model size.Experimental results show that the framework proposed in this paper is able to deploy the pruned model on a real edge device,Jetson TX2,with 6.72 times higher FPS.Meanwhile,the channel pruning reduces the volume and the number of parameters to 96.77%for the model,and the computing amount is reduced to 81.37%.
