The electric double layer(EDL)at the electrochemical interface is crucial for ion transport,charge transfer,and surface reactions in aqueous rechargeable zinc batteries(ARZBs).However,Zn anodes routinely encounter per...The electric double layer(EDL)at the electrochemical interface is crucial for ion transport,charge transfer,and surface reactions in aqueous rechargeable zinc batteries(ARZBs).However,Zn anodes routinely encounter persistent dendrite growth and parasitic reactions,driven by the inhomogeneous charge distribution and water-dominated environment within the EDL.Compounding this,classical EDL theory,rooted in meanfield approximations,further fails to resolve molecular-scale interfacial dynamics under battery-operating conditions,limiting mechanistic insights.Herein,we established a multiscale theoretical calculation framework from single molecular characteristics to interfacial ion distribution,revealing the EDL’s structure and interactions between different ions and molecules,which helps us understand the parasitic processes in depth.Simulations demonstrate that water dipole and sulfate ion adsorption at the inner Helmholtz plane drives severe hydrogen evolution and by-product formation.Guided by these insights,we engineered a“water-poor and anion-expelled”EDL using 4,1’,6’-trichlorogalactosucrose(TGS)as an electrolyte additive.As a result,Zn||Zn symmetric cells with TGS exhibited stable cycling for over 4700 h under a current density of 1 mA cm^(−2),while NaV_(3)O_(8)·1.5H_(2)O-based full cells kept 90.4%of the initial specific capacity after 800 cycles at 5 A g^(−1).This work highlights the power of multiscale theoretical frameworks to unravel EDL complexities and guide high-performance ARZB design through integrated theory-experiment approaches.展开更多
Multi-layer riveted structures are widely applied to aircraft.During the service,cracks may appear within these structures due to stress concentration of the riveted holes.The guided wave monitoring has been proved to...Multi-layer riveted structures are widely applied to aircraft.During the service,cracks may appear within these structures due to stress concentration of the riveted holes.The guided wave monitoring has been proved to be an effective tool to deal with this problem.However,there is a lack of understanding of the wave propagation process across such kinds of structures.This study proposes a piezoelectric guided wave simulation method to reveal the propagation of guided waves in multi-layer riveted structures.Effects of pretension force,friction coefficient,and cracks that might influence wave characteristics are studied.The guided wave simulation data is compared with the experimental results and the results verify the simulation model.Then the guided wave propagation in a more complex long-beam butt joint structure is further simulated.展开更多
Separator modification is an effective approach to suppress dendrite growth to realize high-energy sodium metal batteries(SMBs)in practical applications,however,its success is mainly subject to surface modification.He...Separator modification is an effective approach to suppress dendrite growth to realize high-energy sodium metal batteries(SMBs)in practical applications,however,its success is mainly subject to surface modification.Herein,a separator with multifunctional layers composed of N-doped mesoporous hollow carbon spheres(HCS)as the inner layer and sodium fluoride(NaF)as the outer layer on commercial polypropylene separator(PP)is proposed(PP@HCS-NaF)to achieve stable cycling in SMB.At the molecular level,the inner HCS layer with a high content of pyrrolic-N induces the uniform Na^(+)flux as a potential Na^(+)redistributor for homogenous deposition,whereas its hollow mesoporous structure offers nanoporous buffers and ion channels to regulate Na^(+)ion distribution and uniform deposition.The outer layer(NaF)constructs the NaF-enriched robust solid electrolyte interphase layer,significantly lowering the Na^(+)ions diffusion barrier.Benefiting from these merits,higher electrochemical performances are achieved with multifunctional double-layered PP@HCS-NaF separators compared with single-layered separators(i.e.PP@HCS or PP@NaF)in SMBs.The Na‖Cu half-cell with PP@HCS-NaF offers stable cycling(280 cycles)with a high CE(99.6%),and Na‖Na symmetric cells demonstrate extended lifespans for over 6000 h at 1 mA cm^(-2)with a progressively stable overpotential of 9 mV.Remarkably,in Na‖NVP full-cells,the PP@HCS-NaF separator grants a stable capacity of~81 mA h g^(-1)after 3500 cycles at 1 C and an impressive rate capability performance(~70 mA h g^(-1)at 15 C).展开更多
The umbilical,a key component in offshore energy extraction,plays a vital role in ensuring the stable operation of the entire production system.The extensive variety of cross-sectional components creates highly comple...The umbilical,a key component in offshore energy extraction,plays a vital role in ensuring the stable operation of the entire production system.The extensive variety of cross-sectional components creates highly complex layout combinations.Furthermore,due to constraints in component quantity and geometry within the cross-sectional layout,filler bodies must be incorporated to maintain cross-section performance.Conventional design approaches based on manual experience suffer from inefficiency,high variability,and difficulties in quantification.This paper presents a multi-level automatic filling optimization design method for umbilical cross-sectional layouts to address these limitations.Initially,the research establishes a multi-objective optimization model that considers compactness,balance,and wear resistance of the cross-section,employing an enhanced genetic algorithm to achieve a near-optimal layout.Subsequently,the study implements an image processing-based vacancy detection technique to accurately identify cross-sectional gaps.To manage the variability and diversity of these vacant regions,the research introduces a multi-level filling method that strategically selects and places filler bodies of varying dimensions,overcoming the constraints of uniform-size fillers.Additionally,the method incorporates a hierarchical strategy that subdivides the complex cross-section into multiple layers,enabling layer-by-layer optimization and filling.This approach reduces manufac-turing equipment requirements while ensuring practical production process feasibility.The methodology is validated through a specific umbilical case study.The results demonstrate improvements in compactness,balance,and wear resistance compared with the initial cross-section,offering novel insights and valuable references for filler design in umbilical cross-sections.展开更多
The carcass layer is the innermost structure of flexible marine risers and is responsible for resisting external pressure.It has an“S”section with a spiral interlocking feature.After the multi-pass roll forming of a...The carcass layer is the innermost structure of flexible marine risers and is responsible for resisting external pressure.It has an“S”section with a spiral interlocking feature.After the multi-pass roll forming of a flat steel strip,a carcass layer is formed by lock forming.During roll forming,the steel strip undergoes significant plastic deformation,and its local area accumulates residual stress owing to multiple loading and unloading cycles.These phenomena complicate the design and analysis of the carcass layer multi-pass roll forming(CLMRF)process and cause issues in the carcass layer during manufacturing,such as strip fracture and low forming quality.Thus,herein,CLMRF was investigated to clarify the stress distribution,and a parameter analysis was performed.First,the CLMRF process was designed on the basis of classical roll-forming design theory.Second,a finite element model was established,and CLMRF was simulated.Third,the distributions of the forming stress and residual stress of the strip during CLMRF were investigated.Finally,the influences of the strip thickness,roll gap,roll distance,and angular increment were investigated.The conclusions of this study can be used to provide technical guidance in the manufacturing of flexible risers.展开更多
Because of an unfortunate mistake during the production of this article,the Acknowledgements have been omitted.The Acknowledgements are added as follows:Sasan YAZDANI would like to thank the Scientific and Technologic...Because of an unfortunate mistake during the production of this article,the Acknowledgements have been omitted.The Acknowledgements are added as follows:Sasan YAZDANI would like to thank the Scientific and Technological Research Council of Turkey(TÜB˙ITAK)for receiving financial support for this work through the 2221 Fellowship Program for Visiting Scientists and Scientists on Sabbatical Leave(Grant ID:E 21514107-115.02-228864).Sasan YAZDANI also expresses his gratitude to Sahand University of Technology for granting him sabbatical leave to facilitate the completion of this research.展开更多
To investigate the wind⁃induced vibration re⁃sponse characteristics of multispan double⁃layer cable photo⁃voltaic(PV)support structures,wind tunnel tests using an aeroelastic model were carried out to obtain the wind⁃...To investigate the wind⁃induced vibration re⁃sponse characteristics of multispan double⁃layer cable photo⁃voltaic(PV)support structures,wind tunnel tests using an aeroelastic model were carried out to obtain the wind⁃induced vibration response data of a three⁃span four⁃row double⁃layer cable PV support system.The wind⁃induced vibration characteristics with different PV module tilt angles,wind speeds,and wind direction angles were analyzed.The results showed that the double⁃layer cable large⁃span flexible PV support can effectively control the wind⁃induced vibration response and prevent the occur⁃rence of flutter under strong wind conditions.The maxi⁃mum value of the wind⁃induced vibration displacement of the flexible PV support system occurs in the windward first row.The upstream module has a significant shading effect on the downstream module,with a maximum effect of 23%.The most unfavorable wind direction angles of the structure are 0°and 180°.The change of the wind direction angle in the range of 0°to 30°has little effect on the wind vi⁃bration response.The change in the tilt angle of the PV modules has a greater impact on the wind vibration in the downwind direction and a smaller impact in the upwind di⁃rection.Special attention should be paid to the structural wind⁃resistant design of such systems in the upwind side span.展开更多
The authors regret Acknowledgements Firstly,the authors wish to acknowledge the academic support from Ruhr University Bochum during the first author's(Xiao Yan)research stay from 2018.11 to 2020.10,including the s...The authors regret Acknowledgements Firstly,the authors wish to acknowledge the academic support from Ruhr University Bochum during the first author's(Xiao Yan)research stay from 2018.11 to 2020.10,including the soft code implement and debug support from Vladislav Gudzulic and academic advising from Günther Meschke.展开更多
The charge carrier transport and recombination dynamics in the quantum dots-based light-emitting diodes(QLEDs)featuring multiple emitting layers(M-EMLs)has a great impact on the device performance.In this work,QLEDs b...The charge carrier transport and recombination dynamics in the quantum dots-based light-emitting diodes(QLEDs)featuring multiple emitting layers(M-EMLs)has a great impact on the device performance.In this work,QLEDs based on M-EMLs separated by polyethyleneimine ethoxylated(PEIE)layer with different stacking sequences of blue(B),green(G),and red(R)QDs layer were used to intuitively explore the injection,transportation and recombination processes of the charge carriers in QLEDs by using the time-resolved electroluminescence(TrEL)spectra.From the TrEL spectra mea-surements,green and red emissions were obtained first in the QLEDs with the EMLs sequences of G/PEIE/B/PEIE/R and B/PEIE/R/PEIE/G along the direction of light emission,respectively.While the QLEDs adopt EMLs sequences of B/PEIE/G/PEIE/R,the blue,green and red emissions were obtained nearly at the same time.The above phenomenon can be attributed to different charge carrier transmission and radiation recombination process in the EMLs due to different valence band offsets and conduction band offsets between R-,G-and B-QDs by using different sequences of EMLs.White emission with coordi-nates of(0.31,0.31)and correlated color temperature(CCT)of 5916 K was obtained in the QLEDs with the EMLs se-quences of B/PEIE/G/PEIE/R,which can be attributed to the relative uniform emission of B-,G-and R-QDs due to the effec-tive injection and radiation recombination of charge carriers in each of the EMLs.The above results have great significance for further understanding and improving the performance of QLEDs with M-EMLs.展开更多
Layered rocks(LR)exhibit inherent anisotropic stiffness and strength induced by oriented rough weakness planes,along with stress induced anisotropy and friction related plastic deformation occurs during loading.Furthe...Layered rocks(LR)exhibit inherent anisotropic stiffness and strength induced by oriented rough weakness planes,along with stress induced anisotropy and friction related plastic deformation occurs during loading.Furthermore,microcracks located in intact rock matrix(IRM)of LR are also critically important for friction and damage dissipation processes.In this paper,we first present a novel multiscale friction-damage(MFD)model using a two-step Mori-Tanaka homogenization scheme,with the aim of describing the multiscale friction-damage mechanics in LR.Physically,the initiation and propagation of flaws at different scales(i.e.microcracks and weakness planes)induced damage,and the plastic deformation is closely associated with frictional sliding along these flaws.In the thermodynamics framework,the macroscopic stress-strain relations,the local driving forces respectively conjuncted with flaws propagation and plastic deformation are derived.An analytical macroscopic strength criterion is subsequently deduced,which takes into account the variation of inclination angle and confining pressure.Notably,the failure mechanisms of IRM shearing and weakness planes sliding are inherent included in the criterion.As an original contribution,a new multisurface semi-implicit return mapping algorithm(MSRM)is developed to integrate the proposed MFD model.The robustness of MSRM algorithm is assessed by numerical tests with different loading steps sizes and convergence conditions.Finally,the effectiveness of the MFD model is confirmed using data from experiments under conventional triaxial compression,all main features of mechanical behaviors of LR are well captured by the proposed model,including initial anisotropy,stress-induced anisotropy and strain hardening/softening.展开更多
Although room-temperature superconductivity is still difficult to achieve,researching materials with electrical conductivity significantly higher than that of copper will be of great importance in improving energy eff...Although room-temperature superconductivity is still difficult to achieve,researching materials with electrical conductivity significantly higher than that of copper will be of great importance in improving energy efficiency,reducing costs,lightening equipment weight,and enhancing overall performance.Herein,this study presents a novel copper-carbon nanofilm composite with enhanced conductivity which has great applications in the electronic devices and electrical equipment.Multilayer copper-carbon nanofilms and interfaces with superior electronic structures are formed based on copper materials using plasma immersion nanocarbon layer deposition technology,effectively enhancing conductivity.Experimental results show that for a five-layer copper-carbon nanofilm composite,the conductivity improves significantly when the thickness of the carbon nanofilm increases.When the carbon nanofilm accounts for 16%of the total thickness,the overall conductivity increases up to 30.20%compared to pure copper.The mechanism of the enhanced conductivity is analyzed including roles of copper atom adsorption sites and electron migration pathways by applying effective medium theory,first-principles calculations and density of states analysis.Under an applied electric field,the high-density electrons in the copper film can migrate into the nanocarbon film,forming highly efficient electron transport channels,which significantly enhance the material’s conductivity.Finally,large-area electrode coating equipment is developed based on this study,providing the novel and robust strategy to enhance the conductivity of copper materials,which enables industrial application of copper-carbon nanocomposite films in the field of high conductivity materials.展开更多
Catalytic doping of magnesium hydride(MgH_(2))to improve its hydrogen ab/desorption kinetic properties is considered to be an effective and feasible method.In solid-phase catalysis,the extent of contact between the ca...Catalytic doping of magnesium hydride(MgH_(2))to improve its hydrogen ab/desorption kinetic properties is considered to be an effective and feasible method.In solid-phase catalysis,the extent of contact between the catalyst and the substrate determines the catalytic reaction in a great sense.With large specific surface area and abundant active sites,two-dimensional(2D)nanomaterials are promising catalysts for MgH_(2)via providing numerous pathways for the diffusion and dissociation of hydrogen.In this regard,2D NiMn-based layered double hydroxide and layered metallic oxide(LMO)are designed and introduced into MgH_(2)to improve its hydrogen storage properties.Simultaneous enhancement in interfacial contact,desorption temperature and kinetics are achieved.The MgH_(2)+9wt%Ni3Mn-LMO composites begin to discharge hydrogen at only 190℃and 6.10wt%H_(2)could be charged in 600 s at 150℃.The activation energy for de/hydrogenation is reduced by 42.43%and 46.56%,respectively,compared to pure MgH_(2).Even at a low operating temperature of 235℃,the modified system was still able to release 4.44wt%H_(2)in an hour,which has rarely been reported in previous studies.Microstructure observations and density functional theory calculations revealed that first,the hydrogen pumping effect of Mg_(2)Ni/Mg_(2)NiH_(4) promotes the adsorption and desorption of hydrogen molecules on the surface of MgH_(2),second,MnOx drew electrons from Mg_(2)Ni,producing a new Density of State structure with a lower d-bond center.This unique change further strengthens the Mg_(2)Ni/Mg_(2)NiH_(4) pump effect on MgH_(2).Our work indicates that the application of 2D metal-based catalysts is a feasible and promising approach towards MgH_(2)for solid-state hydrogen storage to meet technical and scientific requirements.展开更多
In the multilayer film-substrate system,thermal stress concentration and stress mutations cause film buckling,delamination and cracking,leading to device failure.In this paper,we investigated a multilayer film system ...In the multilayer film-substrate system,thermal stress concentration and stress mutations cause film buckling,delamination and cracking,leading to device failure.In this paper,we investigated a multilayer film system composed of a substrate and three film layers.The thermal stress distribution inside the structure was calculated by the finite element method,revealing significant thermal stress differences between the layers.This is mainly due to the mismatch of the coefficient of thermal expansion between materials.Different materials respond differently to changes in external temperature,leading to compression between layers.There are obvious thermal stress concentration points at the corners of the base layer and the transition layer,which is due to the sudden change of the shape at the geometric section of the structure,resulting in a sudden increase in local stress.To address this issue,we chamfered the substrate and added an intermediate layer between the substrate and the transition layer to assess whether these modifications could reduce or eliminate the thermal stress concentration points and extend the service life of the multilayer structure.The results indicate that chamfering and adding the intermediate layer effectively reduce stress discontinuities and mitigate thermal stress concentration points,thereby improving interlayer bonding strength.展开更多
Polyacrylonitrile-based commercial carbon fibers(CFs)have garnered significant attention in mechanical applications because of their exceptional mechanical properties.However,their functional versatility relies heavil...Polyacrylonitrile-based commercial carbon fibers(CFs)have garnered significant attention in mechanical applications because of their exceptional mechanical properties.However,their functional versatility relies heavily on the structural intricacies of duplex carbon layers.Current modification approaches,though effective,are encumbered by complexity and cost,limiting widespread adoption across diverse fields.We herein present a straightforward modification strategy centered on regulating carbon layers to unlock the multifunctional potential of CFs.Our method leverages two common anions,Cl^(-)and SO_(4)^(2-),to facilitate oxidation reactions in CFs under robust alkali and high voltage conditions.Cl^(-)effectively activates carbon layers,while SO_(4)^(2-)facilitates layer movement.The electrocatalytic activities of the resultant CFs are enhanced,with state-of-the-art performance as supercapacitors and exceptional stability.Moreover,our approach achieves a groundbreaking milestone by bending and fusing CFs without using binders.This breakthrough can reduce the manufacturing costs of CF-based products.It also facilitates the development of novel microelectronic devices.展开更多
Sodium-based O3-type layered oxide materials are attractive for Sodium-ion batteries(SIBs)due to their simple synthesis,affordability,and high capacity.However,challenges remain,including limited reversible capacity a...Sodium-based O3-type layered oxide materials are attractive for Sodium-ion batteries(SIBs)due to their simple synthesis,affordability,and high capacity.However,challenges remain,including limited reversible capacity and poor cycling stability caused by detrimental phase tran-sitions during cycling and the tendency to form sodium carbonate upon air exposure.In this study,based on O3-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NNFM),a high-entropy strategy was introduced to successfully synthesize O3-type NaNi_(0.25)Fe_(0.21)Mn_(0.18)Co_(0.21)Ti_(0.1)Mg_(0.05)O_(2)(HE-NNFM).The introduction of Co,Ti,and Mg ions increases the system's disorder,highlighting the synergistic interactions among inert atoms.The delayed phase transformation effect in high-entropy materials alleviates the destruction of the O3 structure by the insertion and extraction of sodium ions.Simultaneously,the narrower sodium layer in HE-NNFM acts as a physical barrier,effectively preventing adverse reactions with H2O and CO_(2) in the air,resulting in excellent reversibility and air stability of the HE-NNFM material.Consequently,the HE-NNFM material exhibits a reversible capacity of 110 mAh·g^(-1)with a capacity retention of 97.3%after 200 cycles at 1 C.This work provides insights into the design of high-entropy sodium layered oxides for high-power density storage systems.展开更多
Polyethylene oxide(PEO)-based solid polymer electrolytes are considered as promising material for solidstate sodium metallic batteries(SSMBs).However,their poor interfacial stability with high-voltage cathode limits t...Polyethylene oxide(PEO)-based solid polymer electrolytes are considered as promising material for solidstate sodium metallic batteries(SSMBs).However,their poor interfacial stability with high-voltage cathode limits their application in high-energy–density solid-state batteries.Herein,a uniform,sulfur-containing inorganic–organic composite cathode–electrolyte interphase layer was in situ formed by the addition of sodium polyvinyl sulfonate(NaPVS).The 5 wt%NaPVS-Na_(3)V_(2)(PO_(4))_(3)(NVP)|PEOsodium hexauorophosphate(NaPF6)|Na battery shows a higher initial capacity of 111.2 mAh.g^(-1)and an ultra-high capacity retention of 90.5%after 300 cycles.The 5 wt%NaPVS-Na_(3)V_(2)(PO_(4))_(2)F_(3)(NVPF)|PEO-NaPF_(6)|Na battery with the high cutoff voltage of 4.2 V showed a specific discharge capacity of 88.9 mAh.g^(-1)at 0.5C for 100 cycles with a capacity retention of 79%,which is much better than that of the pristine-NVPF(PR-NVPF)|PEO-NaPF_(6)|Na battery(33.2%).The addition of NaPVS not only enhances the diffusion kinetics at the interface but also improves the rate performance and stability of the battery,thus bolstering its viability for high-energy applications.In situ phase tracking further elucidates that NaPVS effectively mitigates self-discharge induced by the oxidative decomposition of PEO at high temperature.This work proposes a general strategy to maintain the structural stability of the cathode–electrolyte interface in PEO-based high-performance SSMBs.展开更多
For the advancement of fast-charging sodium-ion batteries(SIBs),the synthesis of cutting-edge cathode materials with superior structural stability and enhanced Na+diffusion kinetics is imperative.Multiphase layered tr...For the advancement of fast-charging sodium-ion batteries(SIBs),the synthesis of cutting-edge cathode materials with superior structural stability and enhanced Na+diffusion kinetics is imperative.Multiphase layered transition metal oxides(LTMOs),which leverage the synergistic properties of two distinct monophasic LTMOs,have garnered significant attention;however,their efficacy under fast-charging conditions remains underexplored.In this study,we developed a high-throughput computational screening framework to identify optimal dopants that maximize the electrochemical performance of LTMOs.Specifically,we evaluated the efficacy of 32 dopants based on P2/O3-type Mn/Fe-based Na_(x)Mn_(0.5)Fe_(0.5)O_(2)(NMFO)cathode material.Multiphase LTMOs satisfying criteria for thermodynamic and structural stability,minimized phase transitions,and enhanced Na^(+)diffusion were systematically screened for their suitability in fast-charging applications.The analysis identified two dopants,Ti and Zr,which met all predefined screening criteria.Furthermore,we ranked and scored dopants based on their alignment with these criteria,establishing a comprehensive dopant performance database.These findings provide a robust foundation for experimental exploration and offer detailed guidelines for tailoring dopants to optimize fast-charging SIBs.展开更多
Our concern is to investigate controlled remote implementation of partially unknown operations with multiple layers.We first propose a scheme to realize the remote implementation of singlequbit operations belonging to...Our concern is to investigate controlled remote implementation of partially unknown operations with multiple layers.We first propose a scheme to realize the remote implementation of singlequbit operations belonging to the restricted sets.Then,the proposed scheme is extended to the case of single-qudit operations.As long as the controller and the higher-layer senders consent,the receiver can restore the desired state remotely operated by the sender.It is worth mentioning that the recovery operation is deduced by general formulas which clearly reveal the relationship with the measurement outcomes.For the sake of clarity,two specific examples with two levels are given respectively.In addition,we discuss the influence of amplitude-damping noise and utilize weak measurement and measurement reversal to effectively resist noise.展开更多
Here we report on simultaneous lidar observations of sporadic Ni(Nis)layers and sporadic Na(Nas)layers in the atmosphere over Yanqing,Beijing(40.42°N,116.02°E)from April 2019 to October 2022.During 343 night...Here we report on simultaneous lidar observations of sporadic Ni(Nis)layers and sporadic Na(Nas)layers in the atmosphere over Yanqing,Beijing(40.42°N,116.02°E)from April 2019 to October 2022.During 343 nights of observation,68 Nis and 56 Nas were observed.The seasonal variation of Nis and Nas was also obtained,with the highest occurrence of Nis being in July(43%)and that of Nas being in June(61%).We found that the seasonal variation of Nis is similar to that of Nas and that both occur more frequently in summer than in winter.In addition,we found 23 events in which Nis and Nas occur simultaneously.The average peak altitude of Nas is approximately 1 km higher than that of Nis,and the peak density ratio of Nas to Nis is approximately 5,which is half the density ratio of the two main layers.Additionally,the strength factor for Nas is smaller than that for Nis.Through data analysis of sporadic E layers(Es),we found that Nis and Nas has a significant correlation with Es.The neutralization rates of Ni^(+)/Na^(+)were calculated according to the dissociative recombination reaction of Ni^(+)/Na^(+)and the WACCM-Ni(Whole Atmosphere Community Climate Model of Ni).The production rates of Ni and Na were estimated to be approximately 1:4.4,which is consistent with the density ratio of Nis to Nas.The results showed that the neutralization reaction of Ni+,Na+,and electrons in Es is the main reason for the formation of the Nis layer and the Nas layer.展开更多
To address the issues of frequent identity switches(IDs)and degraded identification accuracy in multi object tracking(MOT)under complex occlusion scenarios,this study proposes an occlusion-robust tracking framework ba...To address the issues of frequent identity switches(IDs)and degraded identification accuracy in multi object tracking(MOT)under complex occlusion scenarios,this study proposes an occlusion-robust tracking framework based on face-pedestrian joint feature modeling.By constructing a joint tracking model centered on“intra-class independent tracking+cross-category dynamic binding”,designing a multi-modal matching metric with spatio-temporal and appearance constraints,and innovatively introducing a cross-category feature mutual verification mechanism and a dual matching strategy,this work effectively resolves performance degradation in traditional single-category tracking methods caused by short-term occlusion,cross-camera tracking,and crowded environments.Experiments on the Chokepoint_Face_Pedestrian_Track test set demonstrate that in complex scenes,the proposed method improves Face-Pedestrian Matching F1 area under the curve(F1 AUC)by approximately 4 to 43 percentage points compared to several traditional methods.The joint tracking model achieves overall performance metrics of IDF1:85.1825%and MOTA:86.5956%,representing improvements of 0.91 and 0.06 percentage points,respectively,over the baseline model.Ablation studies confirm the effectiveness of key modules such as the Intersection over Area(IoA)/Intersection over Union(IoU)joint metric and dynamic threshold adjustment,validating the significant role of the cross-category identity matching mechanism in enhancing tracking stability.Our_model shows a 16.7%frame per second(FPS)drop vs.fairness of detection and re-identification in multiple object tracking(FairMOT),with its cross-category binding module adding aboute 10%overhead,yet maintains near-real-time performance for essential face-pedestrian tracking at small resolutions.展开更多
基金supported by the National Natural Science Foundation of China(52471240)the Natural Science Foundation of Zhejiang Province(LZ23B030003)+2 种基金the Fundamental Research Funds for the Central Universities(226-2024-00075)support from the Engineering and Physical Sciences Research Council(EPSRC,UK)RiR grant-RIR18221018-1EU COST CA23155。
文摘The electric double layer(EDL)at the electrochemical interface is crucial for ion transport,charge transfer,and surface reactions in aqueous rechargeable zinc batteries(ARZBs).However,Zn anodes routinely encounter persistent dendrite growth and parasitic reactions,driven by the inhomogeneous charge distribution and water-dominated environment within the EDL.Compounding this,classical EDL theory,rooted in meanfield approximations,further fails to resolve molecular-scale interfacial dynamics under battery-operating conditions,limiting mechanistic insights.Herein,we established a multiscale theoretical calculation framework from single molecular characteristics to interfacial ion distribution,revealing the EDL’s structure and interactions between different ions and molecules,which helps us understand the parasitic processes in depth.Simulations demonstrate that water dipole and sulfate ion adsorption at the inner Helmholtz plane drives severe hydrogen evolution and by-product formation.Guided by these insights,we engineered a“water-poor and anion-expelled”EDL using 4,1’,6’-trichlorogalactosucrose(TGS)as an electrolyte additive.As a result,Zn||Zn symmetric cells with TGS exhibited stable cycling for over 4700 h under a current density of 1 mA cm^(−2),while NaV_(3)O_(8)·1.5H_(2)O-based full cells kept 90.4%of the initial specific capacity after 800 cycles at 5 A g^(−1).This work highlights the power of multiscale theoretical frameworks to unravel EDL complexities and guide high-performance ARZB design through integrated theory-experiment approaches.
文摘Multi-layer riveted structures are widely applied to aircraft.During the service,cracks may appear within these structures due to stress concentration of the riveted holes.The guided wave monitoring has been proved to be an effective tool to deal with this problem.However,there is a lack of understanding of the wave propagation process across such kinds of structures.This study proposes a piezoelectric guided wave simulation method to reveal the propagation of guided waves in multi-layer riveted structures.Effects of pretension force,friction coefficient,and cracks that might influence wave characteristics are studied.The guided wave simulation data is compared with the experimental results and the results verify the simulation model.Then the guided wave propagation in a more complex long-beam butt joint structure is further simulated.
基金supported by the National Natural Science Foundation of China(Grant Number 22350410379)Zhejiang Provincial Natural Science Foundation of China(LZ23B030003)+1 种基金the Fundamental Research Funds for the Central Universities(226-202400075)Ten Thousand Talent Program of Zhejiang Province.
文摘Separator modification is an effective approach to suppress dendrite growth to realize high-energy sodium metal batteries(SMBs)in practical applications,however,its success is mainly subject to surface modification.Herein,a separator with multifunctional layers composed of N-doped mesoporous hollow carbon spheres(HCS)as the inner layer and sodium fluoride(NaF)as the outer layer on commercial polypropylene separator(PP)is proposed(PP@HCS-NaF)to achieve stable cycling in SMB.At the molecular level,the inner HCS layer with a high content of pyrrolic-N induces the uniform Na^(+)flux as a potential Na^(+)redistributor for homogenous deposition,whereas its hollow mesoporous structure offers nanoporous buffers and ion channels to regulate Na^(+)ion distribution and uniform deposition.The outer layer(NaF)constructs the NaF-enriched robust solid electrolyte interphase layer,significantly lowering the Na^(+)ions diffusion barrier.Benefiting from these merits,higher electrochemical performances are achieved with multifunctional double-layered PP@HCS-NaF separators compared with single-layered separators(i.e.PP@HCS or PP@NaF)in SMBs.The Na‖Cu half-cell with PP@HCS-NaF offers stable cycling(280 cycles)with a high CE(99.6%),and Na‖Na symmetric cells demonstrate extended lifespans for over 6000 h at 1 mA cm^(-2)with a progressively stable overpotential of 9 mV.Remarkably,in Na‖NVP full-cells,the PP@HCS-NaF separator grants a stable capacity of~81 mA h g^(-1)after 3500 cycles at 1 C and an impressive rate capability performance(~70 mA h g^(-1)at 15 C).
基金financially supported by Guangdong Province Basic and Applied Basic Research Fund Project(Grant No.2022B1515250009)Liaoning Provincial Natural Science Foundation-Doctoral Research Start-up Fund Project(Grant No.2024-BSBA-05)+1 种基金Major Science and Technology Innovation Project in Shandong Province(Grant No.2024CXGC010803)the National Natural Science Foundation of China(Grant Nos.52271269 and 12302147).
文摘The umbilical,a key component in offshore energy extraction,plays a vital role in ensuring the stable operation of the entire production system.The extensive variety of cross-sectional components creates highly complex layout combinations.Furthermore,due to constraints in component quantity and geometry within the cross-sectional layout,filler bodies must be incorporated to maintain cross-section performance.Conventional design approaches based on manual experience suffer from inefficiency,high variability,and difficulties in quantification.This paper presents a multi-level automatic filling optimization design method for umbilical cross-sectional layouts to address these limitations.Initially,the research establishes a multi-objective optimization model that considers compactness,balance,and wear resistance of the cross-section,employing an enhanced genetic algorithm to achieve a near-optimal layout.Subsequently,the study implements an image processing-based vacancy detection technique to accurately identify cross-sectional gaps.To manage the variability and diversity of these vacant regions,the research introduces a multi-level filling method that strategically selects and places filler bodies of varying dimensions,overcoming the constraints of uniform-size fillers.Additionally,the method incorporates a hierarchical strategy that subdivides the complex cross-section into multiple layers,enabling layer-by-layer optimization and filling.This approach reduces manufac-turing equipment requirements while ensuring practical production process feasibility.The methodology is validated through a specific umbilical case study.The results demonstrate improvements in compactness,balance,and wear resistance compared with the initial cross-section,offering novel insights and valuable references for filler design in umbilical cross-sections.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.U1906233 and 52201312)Dalian High-Level Talent Innovation Program(Grant No.2021RD16)the Natural Science Foundation of Liaoning Province of China(Grant No.2023-BSBA-052).
文摘The carcass layer is the innermost structure of flexible marine risers and is responsible for resisting external pressure.It has an“S”section with a spiral interlocking feature.After the multi-pass roll forming of a flat steel strip,a carcass layer is formed by lock forming.During roll forming,the steel strip undergoes significant plastic deformation,and its local area accumulates residual stress owing to multiple loading and unloading cycles.These phenomena complicate the design and analysis of the carcass layer multi-pass roll forming(CLMRF)process and cause issues in the carcass layer during manufacturing,such as strip fracture and low forming quality.Thus,herein,CLMRF was investigated to clarify the stress distribution,and a parameter analysis was performed.First,the CLMRF process was designed on the basis of classical roll-forming design theory.Second,a finite element model was established,and CLMRF was simulated.Third,the distributions of the forming stress and residual stress of the strip during CLMRF were investigated.Finally,the influences of the strip thickness,roll gap,roll distance,and angular increment were investigated.The conclusions of this study can be used to provide technical guidance in the manufacturing of flexible risers.
文摘Because of an unfortunate mistake during the production of this article,the Acknowledgements have been omitted.The Acknowledgements are added as follows:Sasan YAZDANI would like to thank the Scientific and Technological Research Council of Turkey(TÜB˙ITAK)for receiving financial support for this work through the 2221 Fellowship Program for Visiting Scientists and Scientists on Sabbatical Leave(Grant ID:E 21514107-115.02-228864).Sasan YAZDANI also expresses his gratitude to Sahand University of Technology for granting him sabbatical leave to facilitate the completion of this research.
基金The National Natural Science Foundation of China(No.52338011).
文摘To investigate the wind⁃induced vibration re⁃sponse characteristics of multispan double⁃layer cable photo⁃voltaic(PV)support structures,wind tunnel tests using an aeroelastic model were carried out to obtain the wind⁃induced vibration response data of a three⁃span four⁃row double⁃layer cable PV support system.The wind⁃induced vibration characteristics with different PV module tilt angles,wind speeds,and wind direction angles were analyzed.The results showed that the double⁃layer cable large⁃span flexible PV support can effectively control the wind⁃induced vibration response and prevent the occur⁃rence of flutter under strong wind conditions.The maxi⁃mum value of the wind⁃induced vibration displacement of the flexible PV support system occurs in the windward first row.The upstream module has a significant shading effect on the downstream module,with a maximum effect of 23%.The most unfavorable wind direction angles of the structure are 0°and 180°.The change of the wind direction angle in the range of 0°to 30°has little effect on the wind vi⁃bration response.The change in the tilt angle of the PV modules has a greater impact on the wind vibration in the downwind direction and a smaller impact in the upwind di⁃rection.Special attention should be paid to the structural wind⁃resistant design of such systems in the upwind side span.
文摘The authors regret Acknowledgements Firstly,the authors wish to acknowledge the academic support from Ruhr University Bochum during the first author's(Xiao Yan)research stay from 2018.11 to 2020.10,including the soft code implement and debug support from Vladislav Gudzulic and academic advising from Günther Meschke.
文摘The charge carrier transport and recombination dynamics in the quantum dots-based light-emitting diodes(QLEDs)featuring multiple emitting layers(M-EMLs)has a great impact on the device performance.In this work,QLEDs based on M-EMLs separated by polyethyleneimine ethoxylated(PEIE)layer with different stacking sequences of blue(B),green(G),and red(R)QDs layer were used to intuitively explore the injection,transportation and recombination processes of the charge carriers in QLEDs by using the time-resolved electroluminescence(TrEL)spectra.From the TrEL spectra mea-surements,green and red emissions were obtained first in the QLEDs with the EMLs sequences of G/PEIE/B/PEIE/R and B/PEIE/R/PEIE/G along the direction of light emission,respectively.While the QLEDs adopt EMLs sequences of B/PEIE/G/PEIE/R,the blue,green and red emissions were obtained nearly at the same time.The above phenomenon can be attributed to different charge carrier transmission and radiation recombination process in the EMLs due to different valence band offsets and conduction band offsets between R-,G-and B-QDs by using different sequences of EMLs.White emission with coordi-nates of(0.31,0.31)and correlated color temperature(CCT)of 5916 K was obtained in the QLEDs with the EMLs se-quences of B/PEIE/G/PEIE/R,which can be attributed to the relative uniform emission of B-,G-and R-QDs due to the effec-tive injection and radiation recombination of charge carriers in each of the EMLs.The above results have great significance for further understanding and improving the performance of QLEDs with M-EMLs.
基金jointly supported by Science and Technology Projects in Guangzhou(Grant No.SL2023A04J01079)Zhejiang ProvincialWater Conservancy Science and Technology Plan Project(Grant No.RC2405)Thematic Five of the Second Scientific Expedition of Qinghai-Tibet Plateau(Grant No.2019QZKK0905).
文摘Layered rocks(LR)exhibit inherent anisotropic stiffness and strength induced by oriented rough weakness planes,along with stress induced anisotropy and friction related plastic deformation occurs during loading.Furthermore,microcracks located in intact rock matrix(IRM)of LR are also critically important for friction and damage dissipation processes.In this paper,we first present a novel multiscale friction-damage(MFD)model using a two-step Mori-Tanaka homogenization scheme,with the aim of describing the multiscale friction-damage mechanics in LR.Physically,the initiation and propagation of flaws at different scales(i.e.microcracks and weakness planes)induced damage,and the plastic deformation is closely associated with frictional sliding along these flaws.In the thermodynamics framework,the macroscopic stress-strain relations,the local driving forces respectively conjuncted with flaws propagation and plastic deformation are derived.An analytical macroscopic strength criterion is subsequently deduced,which takes into account the variation of inclination angle and confining pressure.Notably,the failure mechanisms of IRM shearing and weakness planes sliding are inherent included in the criterion.As an original contribution,a new multisurface semi-implicit return mapping algorithm(MSRM)is developed to integrate the proposed MFD model.The robustness of MSRM algorithm is assessed by numerical tests with different loading steps sizes and convergence conditions.Finally,the effectiveness of the MFD model is confirmed using data from experiments under conventional triaxial compression,all main features of mechanical behaviors of LR are well captured by the proposed model,including initial anisotropy,stress-induced anisotropy and strain hardening/softening.
基金support from the National Natural Science Foundation of China(61574091)National Natural Science Foundation of China Key Program(50730008).
文摘Although room-temperature superconductivity is still difficult to achieve,researching materials with electrical conductivity significantly higher than that of copper will be of great importance in improving energy efficiency,reducing costs,lightening equipment weight,and enhancing overall performance.Herein,this study presents a novel copper-carbon nanofilm composite with enhanced conductivity which has great applications in the electronic devices and electrical equipment.Multilayer copper-carbon nanofilms and interfaces with superior electronic structures are formed based on copper materials using plasma immersion nanocarbon layer deposition technology,effectively enhancing conductivity.Experimental results show that for a five-layer copper-carbon nanofilm composite,the conductivity improves significantly when the thickness of the carbon nanofilm increases.When the carbon nanofilm accounts for 16%of the total thickness,the overall conductivity increases up to 30.20%compared to pure copper.The mechanism of the enhanced conductivity is analyzed including roles of copper atom adsorption sites and electron migration pathways by applying effective medium theory,first-principles calculations and density of states analysis.Under an applied electric field,the high-density electrons in the copper film can migrate into the nanocarbon film,forming highly efficient electron transport channels,which significantly enhance the material’s conductivity.Finally,large-area electrode coating equipment is developed based on this study,providing the novel and robust strategy to enhance the conductivity of copper materials,which enables industrial application of copper-carbon nanocomposite films in the field of high conductivity materials.
基金supports from the National Key R&D Program of China(2020YFA0406204)the National Natural Science Foundation of China(Grant No 51801078).
文摘Catalytic doping of magnesium hydride(MgH_(2))to improve its hydrogen ab/desorption kinetic properties is considered to be an effective and feasible method.In solid-phase catalysis,the extent of contact between the catalyst and the substrate determines the catalytic reaction in a great sense.With large specific surface area and abundant active sites,two-dimensional(2D)nanomaterials are promising catalysts for MgH_(2)via providing numerous pathways for the diffusion and dissociation of hydrogen.In this regard,2D NiMn-based layered double hydroxide and layered metallic oxide(LMO)are designed and introduced into MgH_(2)to improve its hydrogen storage properties.Simultaneous enhancement in interfacial contact,desorption temperature and kinetics are achieved.The MgH_(2)+9wt%Ni3Mn-LMO composites begin to discharge hydrogen at only 190℃and 6.10wt%H_(2)could be charged in 600 s at 150℃.The activation energy for de/hydrogenation is reduced by 42.43%and 46.56%,respectively,compared to pure MgH_(2).Even at a low operating temperature of 235℃,the modified system was still able to release 4.44wt%H_(2)in an hour,which has rarely been reported in previous studies.Microstructure observations and density functional theory calculations revealed that first,the hydrogen pumping effect of Mg_(2)Ni/Mg_(2)NiH_(4) promotes the adsorption and desorption of hydrogen molecules on the surface of MgH_(2),second,MnOx drew electrons from Mg_(2)Ni,producing a new Density of State structure with a lower d-bond center.This unique change further strengthens the Mg_(2)Ni/Mg_(2)NiH_(4) pump effect on MgH_(2).Our work indicates that the application of 2D metal-based catalysts is a feasible and promising approach towards MgH_(2)for solid-state hydrogen storage to meet technical and scientific requirements.
基金the support of the National Natural Science Foundation of China(Grant Nos.51606158,11604311 and 12074151)the Guangxi Science and Technology Base and Talent Special Project(Grant No.AD21075009)+2 种基金the Sichuan Science and Technology Program(Grant No.2021JDRC0022)the Open Fund of the Key Laboratory for Metallurgical Equipment and Control Technology of Ministry of Education in Wuhan University of Science and Technology,People's Republic of China(Grant Nos.MECOF2022B01 and MECOF2023B04)the Guangxi Key Laboratory of Precision Navigation Technology and Application,Guilin University of Electronic Technology(Grant No.DH202321)。
文摘In the multilayer film-substrate system,thermal stress concentration and stress mutations cause film buckling,delamination and cracking,leading to device failure.In this paper,we investigated a multilayer film system composed of a substrate and three film layers.The thermal stress distribution inside the structure was calculated by the finite element method,revealing significant thermal stress differences between the layers.This is mainly due to the mismatch of the coefficient of thermal expansion between materials.Different materials respond differently to changes in external temperature,leading to compression between layers.There are obvious thermal stress concentration points at the corners of the base layer and the transition layer,which is due to the sudden change of the shape at the geometric section of the structure,resulting in a sudden increase in local stress.To address this issue,we chamfered the substrate and added an intermediate layer between the substrate and the transition layer to assess whether these modifications could reduce or eliminate the thermal stress concentration points and extend the service life of the multilayer structure.The results indicate that chamfering and adding the intermediate layer effectively reduce stress discontinuities and mitigate thermal stress concentration points,thereby improving interlayer bonding strength.
基金support from the Key-Area Research and Development Program of Guangdong Province(2019B111107002)the National Natural Science Foundation of China(52478266 and 52108231)+1 种基金the Basic and Applied Basic Research Fund of Guangdong Province(2023A1515012150 and 2023A1515012409)the Shenzhen Science and Technology Innovation Program(20220810140230001 and 20220810160453001).
文摘Polyacrylonitrile-based commercial carbon fibers(CFs)have garnered significant attention in mechanical applications because of their exceptional mechanical properties.However,their functional versatility relies heavily on the structural intricacies of duplex carbon layers.Current modification approaches,though effective,are encumbered by complexity and cost,limiting widespread adoption across diverse fields.We herein present a straightforward modification strategy centered on regulating carbon layers to unlock the multifunctional potential of CFs.Our method leverages two common anions,Cl^(-)and SO_(4)^(2-),to facilitate oxidation reactions in CFs under robust alkali and high voltage conditions.Cl^(-)effectively activates carbon layers,while SO_(4)^(2-)facilitates layer movement.The electrocatalytic activities of the resultant CFs are enhanced,with state-of-the-art performance as supercapacitors and exceptional stability.Moreover,our approach achieves a groundbreaking milestone by bending and fusing CFs without using binders.This breakthrough can reduce the manufacturing costs of CF-based products.It also facilitates the development of novel microelectronic devices.
基金support from Natural Science Foundation of China(Grant Nos.52371187)the Beijing-Tianjin-Hebei Basic Research Cooperation Special Project(B2024209048)+1 种基金the Central Government Guides Local Science and Technology Development Funds of Hebei Province(226Z4403G)the Ph.D.Research Startup Foundation of North China University of Science and Technology(No.BS2019001).
文摘Sodium-based O3-type layered oxide materials are attractive for Sodium-ion batteries(SIBs)due to their simple synthesis,affordability,and high capacity.However,challenges remain,including limited reversible capacity and poor cycling stability caused by detrimental phase tran-sitions during cycling and the tendency to form sodium carbonate upon air exposure.In this study,based on O3-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NNFM),a high-entropy strategy was introduced to successfully synthesize O3-type NaNi_(0.25)Fe_(0.21)Mn_(0.18)Co_(0.21)Ti_(0.1)Mg_(0.05)O_(2)(HE-NNFM).The introduction of Co,Ti,and Mg ions increases the system's disorder,highlighting the synergistic interactions among inert atoms.The delayed phase transformation effect in high-entropy materials alleviates the destruction of the O3 structure by the insertion and extraction of sodium ions.Simultaneously,the narrower sodium layer in HE-NNFM acts as a physical barrier,effectively preventing adverse reactions with H2O and CO_(2) in the air,resulting in excellent reversibility and air stability of the HE-NNFM material.Consequently,the HE-NNFM material exhibits a reversible capacity of 110 mAh·g^(-1)with a capacity retention of 97.3%after 200 cycles at 1 C.This work provides insights into the design of high-entropy sodium layered oxides for high-power density storage systems.
基金supported by the Natural Science Foundation of China(No.22109079)the Natural Science Foundation of China(No.21973008)+2 种基金the Natural Science Foundation of China(No.22179010)the National Key R&D Program of China(No.2021YFB2400200)Taishan Scholars of Shandong Province(No.tsqnz20231212)。
文摘Polyethylene oxide(PEO)-based solid polymer electrolytes are considered as promising material for solidstate sodium metallic batteries(SSMBs).However,their poor interfacial stability with high-voltage cathode limits their application in high-energy–density solid-state batteries.Herein,a uniform,sulfur-containing inorganic–organic composite cathode–electrolyte interphase layer was in situ formed by the addition of sodium polyvinyl sulfonate(NaPVS).The 5 wt%NaPVS-Na_(3)V_(2)(PO_(4))_(3)(NVP)|PEOsodium hexauorophosphate(NaPF6)|Na battery shows a higher initial capacity of 111.2 mAh.g^(-1)and an ultra-high capacity retention of 90.5%after 300 cycles.The 5 wt%NaPVS-Na_(3)V_(2)(PO_(4))_(2)F_(3)(NVPF)|PEO-NaPF_(6)|Na battery with the high cutoff voltage of 4.2 V showed a specific discharge capacity of 88.9 mAh.g^(-1)at 0.5C for 100 cycles with a capacity retention of 79%,which is much better than that of the pristine-NVPF(PR-NVPF)|PEO-NaPF_(6)|Na battery(33.2%).The addition of NaPVS not only enhances the diffusion kinetics at the interface but also improves the rate performance and stability of the battery,thus bolstering its viability for high-energy applications.In situ phase tracking further elucidates that NaPVS effectively mitigates self-discharge induced by the oxidative decomposition of PEO at high temperature.This work proposes a general strategy to maintain the structural stability of the cathode–electrolyte interface in PEO-based high-performance SSMBs.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(No.2022R1F1A1074339)。
文摘For the advancement of fast-charging sodium-ion batteries(SIBs),the synthesis of cutting-edge cathode materials with superior structural stability and enhanced Na+diffusion kinetics is imperative.Multiphase layered transition metal oxides(LTMOs),which leverage the synergistic properties of two distinct monophasic LTMOs,have garnered significant attention;however,their efficacy under fast-charging conditions remains underexplored.In this study,we developed a high-throughput computational screening framework to identify optimal dopants that maximize the electrochemical performance of LTMOs.Specifically,we evaluated the efficacy of 32 dopants based on P2/O3-type Mn/Fe-based Na_(x)Mn_(0.5)Fe_(0.5)O_(2)(NMFO)cathode material.Multiphase LTMOs satisfying criteria for thermodynamic and structural stability,minimized phase transitions,and enhanced Na^(+)diffusion were systematically screened for their suitability in fast-charging applications.The analysis identified two dopants,Ti and Zr,which met all predefined screening criteria.Furthermore,we ranked and scored dopants based on their alignment with these criteria,establishing a comprehensive dopant performance database.These findings provide a robust foundation for experimental exploration and offer detailed guidelines for tailoring dopants to optimize fast-charging SIBs.
基金supported by the National Natural Science Foundation of China(Grant Nos.62172341,12071132)the Natural Science Foundation of Henan Province of China(Grant No.242300420276)the Joint Fund of Henan Province Science and Technology R&D Program(Grant No.225200810032)。
文摘Our concern is to investigate controlled remote implementation of partially unknown operations with multiple layers.We first propose a scheme to realize the remote implementation of singlequbit operations belonging to the restricted sets.Then,the proposed scheme is extended to the case of single-qudit operations.As long as the controller and the higher-layer senders consent,the receiver can restore the desired state remotely operated by the sender.It is worth mentioning that the recovery operation is deduced by general formulas which clearly reveal the relationship with the measurement outcomes.For the sake of clarity,two specific examples with two levels are given respectively.In addition,we discuss the influence of amplitude-damping noise and utilize weak measurement and measurement reversal to effectively resist noise.
基金supported by the Specialized Research Fund for State Key Laboratories,Chinese Meridian Project,the Specialized Research Fund for the State Key Laboratory of Solar Activity and Space Weather,postgraduate Education Reform and Quality Improvement Project of Henan Province(Grant No.YJS2024JD32)Natural Science Foundation Project of Henan Province(Grant No.242300420253)National Natural Science Foundation of China for Young Scientists(Grant No.42504156)funding.
文摘Here we report on simultaneous lidar observations of sporadic Ni(Nis)layers and sporadic Na(Nas)layers in the atmosphere over Yanqing,Beijing(40.42°N,116.02°E)from April 2019 to October 2022.During 343 nights of observation,68 Nis and 56 Nas were observed.The seasonal variation of Nis and Nas was also obtained,with the highest occurrence of Nis being in July(43%)and that of Nas being in June(61%).We found that the seasonal variation of Nis is similar to that of Nas and that both occur more frequently in summer than in winter.In addition,we found 23 events in which Nis and Nas occur simultaneously.The average peak altitude of Nas is approximately 1 km higher than that of Nis,and the peak density ratio of Nas to Nis is approximately 5,which is half the density ratio of the two main layers.Additionally,the strength factor for Nas is smaller than that for Nis.Through data analysis of sporadic E layers(Es),we found that Nis and Nas has a significant correlation with Es.The neutralization rates of Ni^(+)/Na^(+)were calculated according to the dissociative recombination reaction of Ni^(+)/Na^(+)and the WACCM-Ni(Whole Atmosphere Community Climate Model of Ni).The production rates of Ni and Na were estimated to be approximately 1:4.4,which is consistent with the density ratio of Nis to Nas.The results showed that the neutralization reaction of Ni+,Na+,and electrons in Es is the main reason for the formation of the Nis layer and the Nas layer.
基金supported by the confidential research grant No.a8317。
文摘To address the issues of frequent identity switches(IDs)and degraded identification accuracy in multi object tracking(MOT)under complex occlusion scenarios,this study proposes an occlusion-robust tracking framework based on face-pedestrian joint feature modeling.By constructing a joint tracking model centered on“intra-class independent tracking+cross-category dynamic binding”,designing a multi-modal matching metric with spatio-temporal and appearance constraints,and innovatively introducing a cross-category feature mutual verification mechanism and a dual matching strategy,this work effectively resolves performance degradation in traditional single-category tracking methods caused by short-term occlusion,cross-camera tracking,and crowded environments.Experiments on the Chokepoint_Face_Pedestrian_Track test set demonstrate that in complex scenes,the proposed method improves Face-Pedestrian Matching F1 area under the curve(F1 AUC)by approximately 4 to 43 percentage points compared to several traditional methods.The joint tracking model achieves overall performance metrics of IDF1:85.1825%and MOTA:86.5956%,representing improvements of 0.91 and 0.06 percentage points,respectively,over the baseline model.Ablation studies confirm the effectiveness of key modules such as the Intersection over Area(IoA)/Intersection over Union(IoU)joint metric and dynamic threshold adjustment,validating the significant role of the cross-category identity matching mechanism in enhancing tracking stability.Our_model shows a 16.7%frame per second(FPS)drop vs.fairness of detection and re-identification in multiple object tracking(FairMOT),with its cross-category binding module adding aboute 10%overhead,yet maintains near-real-time performance for essential face-pedestrian tracking at small resolutions.
