Visible and infrared(RGB-IR)fusion object detection plays an important role in security,disaster relief,etc.In recent years,deep-learning-based RGB-IR fusion detection methods have been developing rapidly,but still st...Visible and infrared(RGB-IR)fusion object detection plays an important role in security,disaster relief,etc.In recent years,deep-learning-based RGB-IR fusion detection methods have been developing rapidly,but still struggle to deal with the complex and changing scenarios captured by drones,mainly due to two reasons:(A)RGB-IR fusion detectors are susceptible to inferior inputs that degrade performance and stability.(B)RGB-IR fusion detectors are susceptible to redundant features that reduce accuracy and efficiency.In this paper,an innovative RGB-IR fusion detection framework based on global-local feature optimization,named GLFDet,is proposed to improve the detection performance and efficiency of drone-captured objects.The key components of GLFDet include a Global Feature Optimization(GFO)module,a Local Feature Optimization(LFO)module and a Channel Separation Fusion(CSF)module.Specifically,GFO calculates the information content of the input image from the frequency domain and optimizes the features holistically.Then,LFO dynamically selects high-value features and filters out low-value features before fusion,which significantly improves the efficiency of fusion.Finally,CSF fuses the RGB and IR features across the corresponding channels,which avoids the rearrangement of the channel relationships and enhances the model stability.Extensive experimental results show that the proposed method achieves the best performance on three popular RGB-IR datasets Drone Vehicle,VEDAI,and LLVIP.In addition,GLFDet is more lightweight than other comparable models,making it more appealing to edge devices such as drones.The code is available at https://github.com/lao chen330/GLFDet.展开更多
Background and Objectives:The perception of sound in the vertical plane supports spatial hearing by enabling listeners to detect sources located above and below.Sounds originating from both the front and back elevatio...Background and Objectives:The perception of sound in the vertical plane supports spatial hearing by enabling listeners to detect sources located above and below.Sounds originating from both the front and back elevations along the mid-sagittal plane further contribute to a three-dimensional auditory experience.This study aimed to characterize the variability in vertical sound localization abilities among normal-hearing(NH)individuals using spatialized audio.Materials and Methods:Fifty-one NH participants(aged 18 to 35 years)completed three vertical localization tasks under headphones as part of a single-group,within-subject experimental study.These tasks included two-plane identification:(1)top-down localization,(2)front-back localization,and one discrimination task in the front plane.Hierarchical Cluster Analysis(HCA)was employed to identify distinct patterns in spatial localization profiles specific to the vertical-median plane.Fisher's Discriminant Function Analysis(FDA)was used to validate the accuracy of HCA and estimate classification error.Results:HCA revealed three distinct listener clusters:(1)cluster 1 with good performance across all three tasks,(2)cluster 2 with selective impairment in top-bottom identification,and(3)cluster 3 with selective deficits in front-back identification.FDA validated group membership of the clusters identified by the HCA,with a prediction accuracy of 98%.Conclusions:Individuals with clinically NH exhibited three distinct vertical localization profiles:uniform performers,those impaired in top-bottom identification,and those impaired in front-back identification.These profiles may be linked to the interplay between acoustic and non-acoustic perceptual factors.展开更多
Polyaniline(PANI)exhibits remarkable electrical conductivity and mechanical flexibility,rendering it widely applicable in flexible electronic devices.For instance,it serves as a channel layer material in Organic Elect...Polyaniline(PANI)exhibits remarkable electrical conductivity and mechanical flexibility,rendering it widely applicable in flexible electronic devices.For instance,it serves as a channel layer material in Organic Electrochemical Transistors(OECTs).In OECTs,the conductivity of the channel layer plays a pivotal role in dictating the switching speed and current-carrying capacity of the device.Proton acid doping represents an efficacious approach to enhancing the conductivity of polymers.However,the efficiency of direct doping of protic acid is low,thereby imposing limitations on the conductivity of polyaniline.In this study,ultrafast photoexcitation was implemented to efficiently improve the conductivity of camphor sulfonic acid(CSA)doped PANI films.Upon reaching a laser fluence of 166.2 mJ cm^(-2),the conductivity of PANI films experienced a remarkable increment of nearly four orders of magnitude,soaring to 117.6 S m^(-1),while its sheet resistance decreased to 170.9Ωsq^(-1).Meanwhile,fs-laser-treated PANI-CSA films exhibited excellent stability.The PANI-based OECT device was prepared,and the transconductance escalated from 0.113 to 0.503 mS,representing an increase exceeding fourfold.Our work provides a simple,eco-friendly,and sustainable processing technology for the preparation of high-performance PANI flexible conductive films,showing great application potential for flexible electronic devices.展开更多
Proton exchange membrane(PEM)is an integral component in fuel cells which enables proton transport for efficient energy conversion.Sulfonated Polyether Ether Ketone(SPEEK)has emerged as a cost-effective option with no...Proton exchange membrane(PEM)is an integral component in fuel cells which enables proton transport for efficient energy conversion.Sulfonated Polyether Ether Ketone(SPEEK)has emerged as a cost-effective option with non-fluorinated aromatic backbones for Proton Exchange Membrane Fuel Cell(PEMFC)applications,even though it exhibits lower proton conductivity compared to Nafion.This work aims to study the influence of Sulfonated Chitosan(SCS)concentrations on proton conductivity of SPEEK-based PEM at room temperature.SPEEK was synthesized using a sulfonation process with concentrated sulfuric acid at room temperature.SCS was synthesized via reflux of CS and 1.2 M H2SO4 with a ratio of 1:35(w/v)at 90℃ for 30 min.The composite membranes of SPEEK-SCS were formed with four different SCS concentrations,using the solution castingmethod,andDimethyl Sulfoxide(DMSO)was used as a solvent.The composite membranes synthesized include pure SPEEK(S0),SPEEK with 1%SCS(S1),SPEEK with 2%SCS(S2),and SPEEK with 3%SCS(S3).Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD),water uptake,degree of swelling,Ionic exchange capacity(IEC)with Electrochemical impedance spectroscopy(EIS)were used to characterize the composite membranes in terms of composition,crystallinity,water absorption,dimensional changes,number of exchangeable ions in membranes,and proton conductivity,respectively.Notably,S3 had the highest water uptake and the lowest degree of swelling.S2 had the highest proton conductivity among the SPEEK-SCS composite membranes at room temperature with 3.44×10^(−2) Scm^(-1).展开更多
The application potential of tuning two-dimensional materials(2DMs)characteristics through strain engineering for wearable and flexible devices has been widely recognized.However,the challenges lie in achieving accura...The application potential of tuning two-dimensional materials(2DMs)characteristics through strain engineering for wearable and flexible devices has been widely recognized.However,the challenges lie in achieving accurate deterministic positioning,spatial modulation,controllable magnitude,and permanent nanostrains.Herein,motivated by the skin swelling caused by mosquito bites,a technique utilizing the heated nanotip in atomic force microscopy for thermomechanical nanoindentation is demonstrated.This method enables precise positioning of localized nanostrain and regulation of bandgap in tungsten diselenide(WSe_(2))/molybdenum disulfide(MoS_(2))heterobilayer transferred onto a flexible polymethyl methacrylate film.The magnitude of strain in the WSe_(2)/MoS_(2) heterobilayer can be controlled by adjusting the parameters of nanoindentation,leading to a spatially modulated average strain of up to 2.5%on the ring-shaped expansion structure(RES).The local bandgap of the WSe_(2)/MoS_(2) heterobilayer is spatially regulated through three distinct regions.In particular,the RES exhibits the largest extent of bandgap modulation,accompanied by a significant change of~12 meV.The nanostrain significantly enhances the photoresponse speed of the photodetector device.For instance,under illumination from a 405 nm wavelength-laser,the rise time and fall time are reduced by 75%and 87.52%,respectively,compared to the device without strain.Similarly,under illumination from a 532 nm wavelength-laser,the rise time and fall time are reduced by 66.67%and 80.60%,respectively.These findings demonstrate that the proposed method serves as a versatile way for improving the photoresponse of optoelectronic devices based on 2DMs.展开更多
With the miniaturization and high-frequency evolution of antennas in 5G/6G communications,aerospace,and transportation,polymer composite papers integrating superior wave-transparent performance and thermal conductivit...With the miniaturization and high-frequency evolution of antennas in 5G/6G communications,aerospace,and transportation,polymer composite papers integrating superior wave-transparent performance and thermal conductivity for radar antenna systems are urgently needed.Herein,a down-top strategy was employed to synthesize poly(p-phenylene benzobisoxazole)precursor nanofibers(prePNF).The prePNF was then uniformly mixed with fluorinated graphene(FG)to fabricate FG/PNF composite papers through consecutively suction filtration,hot-pressing,and thermal annealing.The hydroxyl and amino groups in prePNF enhanced the stability of FG/prePNF dispersion,while the increasedπ-πinteractions between PNF and FG after annealing improved their compatibility.The preparation time and cost of PNF paper was significantly reduced when applying this strategy,which enabled its large-scale production.Furthermore,the prepared FG/PNF composite papers exhibited excellent wave-transparent performance and thermal conductivity.When the mass fraction of FG was 40 wt%,the FG/PNF composite paper prepared via the down-top strategy achieved the wave-transparent coefficient(|T|2)of 96.3%under 10 GHz,in-plane thermal conductivity(λ_(∥))of 7.13 W m^(−1)K^(−1),and through-plane thermal conductivity(λ_(⊥))of 0.67 W m^(−1)K^(−1),outperforming FG/PNF composite paper prepared by the top-down strategy(|T|2=95.9%,λ_(∥)=5.52 W m^(−1)K^(−1),λ_(⊥)=0.52 W m^(−1)K^(−1))and pure PNF paper(|T|2=94.7%,λ_(∥)=3.04 W m^(−1)K^(−1),λ_(⊥)=0.24 W m^(−1)K^(−1)).Meanwhile,FG/PNF composite paper(with 40 wt%FG)through the down-top strategy also demonstrated outstanding mechanical properties with tensile strength and toughness reaching 197.4 MPa and 11.6 MJ m^(−3),respectively.展开更多
The thermal conductivity of nanofluids is an important property that influences the heat transfer capabilities of nanofluids.Researchers rely on experimental investigations to explore nanofluid properties,as it is a n...The thermal conductivity of nanofluids is an important property that influences the heat transfer capabilities of nanofluids.Researchers rely on experimental investigations to explore nanofluid properties,as it is a necessary step before their practical application.As these investigations are time and resource-consuming undertakings,an effective prediction model can significantly improve the efficiency of research operations.In this work,an Artificial Neural Network(ANN)model is developed to predict the thermal conductivity of metal oxide water-based nanofluid.For this,a comprehensive set of 691 data points was collected from the literature.This dataset is split into training(70%),validation(15%),and testing(15%)and used to train the ANN model.The developed model is a backpropagation artificial neural network with a 4–12–1 architecture.The performance of the developed model shows high accuracy with R values above 0.90 and rapid convergence.It shows that the developed ANN model accurately predicts the thermal conductivity of nanofluids.展开更多
To investigate the long-term fracture conductivity behavior of propped fractures under the high-temperature and high-pressure conditions of deep shale gas reservoirs in the Sichuan Basin,this study systematically anal...To investigate the long-term fracture conductivity behavior of propped fractures under the high-temperature and high-pressure conditions of deep shale gas reservoirs in the Sichuan Basin,this study systematically analyzed the effects of closure stress,proppant concentration,formation temperature,and proppant size combination.Conductivity experiments were conducted using the HXDL-2C long-term proppant conductivity evaluation system under simulated reservoir conditions to determine the time-dependent evolution of fracture conductivity.The results showed that the 50-h conductivity retention of the rock-plate experiments ranged from 22%to 28%.With increasing closure stress,fracture conductivity exhibited a rapid decline.Under a formation temperature of 120℃ and a proppant concentration of 5 kg·m^(-2),the short-term conductivity of 70/140 mesh quartz-sand-propped fractures was 2.37μm^(2)·cm,which decreased to 0.66μm^(2)·cm after long-term testing.When the closure stress increased to 80 MPa,the short-term and long-term conductivities further declined to 1.36μm^(2)·cm and 0.39μm^(2)·cm,respectively.Increasing the proppant concentration from 5 to 7.5 kg·m^(-2)at 120℃ and 80 MPa improved both short-term and long-term conductivities by enlarging the effective fracture width;however,the conductivity decay rate accelerated,and the 50-h retention dropped from 27.2%to 22.8%.Raising the temperature from 120℃ to 140℃ promoted proppant crushing and compaction,intensified shale creep,and accelerated fracture closure,reducing long-term conductivity from 0.37 to 0.30μm^(2)·cm.Under identical conditions,40/70 mesh ceramic proppants maintained significantly higher conductivities than 70/140 mesh quartz sand,with short-term and long-term values of 8.71 and 2.19μm^(2)·cm,respectively,at 120℃,80 MPa,and 5 kg·m^(-2).Pure quartz-sand systems failed to maintain effective conductivity under high-temperature and high-stress conditions,whereas adding 20%40/70 mesh ceramic proppant and thoroughly mixing it,the long-term conductivity has increased by 2.3 times,improving fracture stability while reducing overall cost.A predictive equation was derived from the experimental results to capture the dynamic decay characteristics of fracture conductivity.These outcomes provide a valuable experimental basis and technical support for optimizing fracturing fluid design,proppant selection,and operation parameters in deep shale formations.展开更多
This paper is concerned with an initial boundary value problem for the planar magnetohydrodynamic compressible flow with temperature dependent heat conductivity in a half-line.In particular,the transverse magnetic fie...This paper is concerned with an initial boundary value problem for the planar magnetohydrodynamic compressible flow with temperature dependent heat conductivity in a half-line.In particular,the transverse magnetic field is assumed to satisfy the Neumann boundary condition,which was first investigated by Kazhikhov in 1987.We establish the global existence of the unique strong solutions to the MHD equations without any smallness conditions on the initial data.More precisely,our result can be regarded as a natural generalization of Kazhikov’s result for applying the constant heat-conductivity in bounded domains to the degenerate case in unbounded domains.展开更多
Conducting hydrogels have garnered significant interest in the field of wearable electronics.However,simultaneously achieving high transparency,high conductivity,strong adhesion,and self-healing ability within a short...Conducting hydrogels have garnered significant interest in the field of wearable electronics.However,simultaneously achieving high transparency,high conductivity,strong adhesion,and self-healing ability within a short time remains a major challenge.In this study,a multifunctional mussel-inspired hydrogel was synthesized in only 5 min,with polydopamine(PDA)-polypyrrole(Ppy)-polyaniline(PANi)and poly(vinyl alcohol)(PVA)nanoparticles incorporated into the polyacrylamide(PAM)network.The resulting hydrogel exhibited high transparency(about 90% light transmission in the range of 400-800 nm),high conductivity((95.4±0.4)×10^(-4)S/cm),tensile strength(32.60±1.03 k Pa),strain at break(904.46%±11.50%),and adhesive strength(30-60 k Pa).It also demonstrated rapid self-healing properties(about 48% strength recovery within 1h at 50℃)and water-dependent shape memory behavior.As a wearable strain sensor,the hydrogel successfully detected finger flexion,wrist movements,facial expression changes,and breathing with high sensitivity and stability.The calculated gauge factor(GF)was 7.44±0.31,which is higher than that of many previously reported hydrogels.Compared with previous oyster-inspired or Ppy-based hydrogels,our system showed a much shorter synthesis time,higher transparency,and enhanced multifunctionality.These findings highlight the potential of the proposed hydrogel for next-generation flexible electronics,e-skin,and biomedical monitoring devices.展开更多
There is an urgent need to develop magnesium-matrix materials that exhibit both high thermal conductivity and low thermal expansion to ensure compatibility with chips.This study aims to develop a Mg-Zn-Cu alloy with h...There is an urgent need to develop magnesium-matrix materials that exhibit both high thermal conductivity and low thermal expansion to ensure compatibility with chips.This study aims to develop a Mg-Zn-Cu alloy with high thermal conductivity.Furthermore,it explores the preparation of AlN_(P)/Mg-Zn-Cu composites featuring low coefficients of thermal expansion.The stir casting method was utilized to fabricate the composites and an investigation was conducted to examine their microstructure and thermal properties.Results indicate that the addition of AlN_(P)reduces the thermal expansion coefficient while maintaining relatively high thermal conductivity.Specifically,the AlN_(P)/Mg-0.5Zn-0.5Cu composite with 30wt.%AlN_(P)achieves a thermal conductivity of 132.7 W·m^(-1)·K^(-1)and a thermal expansion coefficient of 18.5×10^(-6)K^(-1),rendering it suitable for electronic packaging applications where thermal management is critical.展开更多
This paper proposes a tamper detection technique for semi-fragile watermarking using Quantizationbased Discrete Cosine Transform(DCT)for tamper localization.In this study,the proposed embedding strategy is investigate...This paper proposes a tamper detection technique for semi-fragile watermarking using Quantizationbased Discrete Cosine Transform(DCT)for tamper localization.In this study,the proposed embedding strategy is investigated by experimental tests over the diagonal order of the DCT coefficients.The cover image is divided into non-overlapping blocks of size 8×8 pixels.The DCT is applied to each block,and the coefficients are arranged using a zig-zag pattern within the block.In this study,the low-frequency coefficients are selected to examine the impact of the imperceptibility score and tamper detection accuracy.High accuracy of tamper detection can be achieved by checking the surrounding blocks to determine whether the corresponding block has been tampered with.The proposed tamper detection is tested under various malicious,incidental,and hybrid attacks(both incidental and malicious attacks).The experimental results demonstrate that the proposed technique achieves a Peak-Signal-to-Noise Ratio(PSNR)value of 41.2318 dB,an average Structural Similarity Index Measure(SSIM)value of 0.9768.The proposed scheme is also evaluated against malicious attacks such as copy-move,object deletion,object manipulation,and collage attacks.The proposed scheme can detect the malicious attack localization under various tampering rates.In addition,the proposed scheme can still detect tampered pixels under a hybrid attack,such as a combination ofmalicious and incidental attacks,with an average accuracy of 96.44%.展开更多
The acquisition of position information of legitimate users and jammers plays an important role in the emerging non-geostationary synchronous orbit(NGSO)satellite communications.In this paper,we study the multi-signal...The acquisition of position information of legitimate users and jammers plays an important role in the emerging non-geostationary synchronous orbit(NGSO)satellite communications.In this paper,we study the multi-signal localization problem in an uplink NGSO satellite communication system.We propose an onboard localization scheme based on multiple observations from the satellite,together with the geometric constraints of the satellite postions,the signal positions,the attitude of the satellite,and the angle-of-arrival(AoAs)of the signals.We develop a massage-passing algorithm,termed the Bayesian blind multi-signal localization(BMSL),to jointly estimate the AoAs and the signal positions.The Cramér-Rao lower bound(CRLB)is derived to characterize the fundamental performance limit of the considered localization problem.Simulation results show that the proposed BMSL algorithm can perform close to the derived CRLB and significantly outperforms its counterpart algorithms.展开更多
Localized high-concentration electrolytes(LHCEs)are considered as promising electrolyte candidates to resolve technical issues of metal batteries owing to their unique interfacial properties and solvation structures.H...Localized high-concentration electrolytes(LHCEs)are considered as promising electrolyte candidates to resolve technical issues of metal batteries owing to their unique interfacial properties and solvation structures.Herein,we propose a self-assembly chemical strategy into the LCHEs induced by ordered nanostructure of zwitterionic co-solutes for highly efficient and ultrastable zinc(Zn)metal batteries.Through the systematic screening of six zwitterionic compounds,3-(decyldimethylammonio)propanesulfonate salt(C_(10))with the decyl chain and zwitterions was determined as an optimum to construct quasi-spherical aggregates with a periodic length of 3.77 nm,as confirmed by comprehensive synchronous small-angle X-ray scattering,Guinier,pair distance distribution function,Porod,and other spectroscopic characterizations and molecular dynamic simulation.In particularly,this self-assembled structure in electrolyte environments was attributed to increasing the proportion of both contact and aggregated ion pairs for the formation of LHCEs as well as to providing fast and selective Zn^(2+)conducting channels and uniform solid electrolyte interfaces for facilitated charge transfer kinetics.Moreover,the preferential adsorption of the self-assembled C_(10)on the Zn(002)surface modulated the electrical double layer to suppress hydrogen evolution and corrosion reactions.Consequently,the Zn‖Zn symmetric cells in Zn(OTf)_(2)/C_(10)electrolytes showed long-term plating/stripping behaviors over 2800 h at 1 mA cm^(-2)and 1 mAh cm^(-2)as well as over 1200 h even at 5 mA cm^(-2)and 5 mAh cm^(-2)with a very high depth of discharge of 42.7%.Furthermore,the ZnllVO_(2)/CNT full cells in Zn(OTf)_(2)/C_(10)electrolytes delivered a record-high capacity of 8.10 mAh cm^(-2)at an ultrahigh cathode mass loading of 50 mg cm^(-2)after 150 cycles.展开更多
In this paper,a theoretical model is established for locally resonant plates with general resonators,and the corresponding governing equation is derived.The model provides a mathematical demonstration of the locally r...In this paper,a theoretical model is established for locally resonant plates with general resonators,and the corresponding governing equation is derived.The model provides a mathematical demonstration of the locally resonant effect,which contains two parts:the first part is induced by translation coupling,and the second part is induced by rotation coupling.The second part cannot be reflected by most existing theoretical models.The analytical solutions of the dynamic response are compared with the direct numerical simulation(DNS)results for two locally resonant plates with different resonator types,thereby validating the general applicability of the present model.The rotation coupling effect leads to the frequency-dependent effective rotational inertia density and anisotropic dispersion relation of the locally resonant plate,as well as the enhancement of the structural vibration suppression ability.展开更多
The stator of the maglev track plays a crucial role in the operation of the maglev system.Currently,the efficiency of maglev track inspection is limited by several factors,including the large span of elevated structur...The stator of the maglev track plays a crucial role in the operation of the maglev system.Currently,the efficiency of maglev track inspection is limited by several factors,including the large span of elevated structures,manual visual inspection,short inspection window times,and limited GPS positioning accuracy.To address these issues,this paper proposes a deep learning-based method for detecting and locating stator surface damage.This study establishes a maglev track stator surface image dataset,trains different object detection models,and compares their performance.Ultimately,YOLO and ByteTrack object tracking algorithms were chosen as the basic framework and enhanced to achieve automatic identification of high-speed maglev track stator surface damage images and track and count stator surface localization feature images.By matching the identified damaged images with their corresponding stator segment and beam segment sequence numbers,the location of the damage is pinpointed to the corresponding stator segment,enabling rapid and accurate identification and localization of complex damage to the maglev track stator surface.展开更多
In this article,we introduce a new theoretical approach to improve the accuracy of twodimensional(2D)atomic localization within a tripod-type,four-level atomic system by analyzing its transmission spectrum.In this met...In this article,we introduce a new theoretical approach to improve the accuracy of twodimensional(2D)atomic localization within a tripod-type,four-level atomic system by analyzing its transmission spectrum.In this method,the atom interacts with two orthogonal standing-wave fields and a weak probe field.By examining how the weak probe field passes through the system,we can determine the atom position.Our analysis reveals the presence of both double and sharply defined single localized peaks in the transmission spectrum,which correspond to specific positions of the atom.Importantly,we achieve ultra-high-resolution atomic localization with accuracy confined to a region smaller thanλ/32×λ/32.This level of precision is a significant improvement compared to earlier methods,which had lower localization accuracy.The increased precision is due to the complex interaction between the atom and the carefully controlled standing-wave and probe fields,which allows for precise control over the atom's position.The implications of this work are significant,especially for applications like nano-lithography,where precise atomic placement is essential,and for laser cooling technologies,where better atomic localization could lead to more effective cooling processes and improved manipulation of atomic states.展开更多
Hydrochloric acid(HCl)extensively exists in deep underground projects,arising from the transportation of industrial raw materials or fracturing fluids of petroleum engineering.It results in corrosion,which can signifi...Hydrochloric acid(HCl)extensively exists in deep underground projects,arising from the transportation of industrial raw materials or fracturing fluids of petroleum engineering.It results in corrosion,which can significantly impact the stability of surrounding rock structures.Therefore,in-depth analysis of the degradation of rock corroded by the HCl solution is an essential task for underground engineering.In this study,the granite specimens are initially treated with the HCl solution with various concentrations.Then,the tests and analyses,such as electrical conductivity(EC)measurements,mineral composition assays,and Brazilian splitting tests,are employed to investigate the corrosion mechanism of the HCl solution.Our results and findings are generally as follows:(1)As the immersion time increases,the EC exhibits a relatively high level at pH value of 1,a decreasing trend at pH value of 3,and an increasing trend at pH value of 5 and 7.(2)The HCl solutions with various concentration have different effect on mineral composition,characterized by an increase in proportion of SiO_(2) and a reduction in proportion of Na_(2)O,Al_(2)O_(3),K_(2)O,MgO,and CaO,as the solution pH value decreases.(3)After immersion in the solutions with pH values of 1,3,and 5,the tensile strength of the granite decreases by 23.85%,20.84%,and 20.24%;the average stiffness of the specimen decreases by 29.29%,23.43%,and 11.97%;the proportion of releasable energy increases by 6%,4%,and -2%;the releasable energy decreases by 54.96%,26.09%,and 14.52%;and the dissipated energy decreases by approximately 68.85%,41.39%,and 5.41%,respectively.(4)The evolution of physical and mechanical properties of the immersed granite specimen can be analyzed from a chemical aspect.The corrosive action of HCl cleaves Si–O and Al–O chemical bonds within the granite,particularly altering the tetrahedral structures of its silicate components.This process involves breaking existing chemical bonds and the formation of new ones,ultimately destroying the silicate molecular structures.As the concentration of HCl increases,the rate of these reactions accelerates,progressively weakening the chemical bonds and consequently deteriorating the mechanical characteristics of the granite.These findings can deepen our knowledge about the corrosion effect of HCI solutions on natural surrounding rocks and serve as references for further research on rock corrosion mechanisms in underground engineering.展开更多
Binary segmentation tasks in computer vision exhibit diverse appearance distributions and complex boundary characteristics.To address the limited generalization and adaptability of existing models across heterogeneous...Binary segmentation tasks in computer vision exhibit diverse appearance distributions and complex boundary characteristics.To address the limited generalization and adaptability of existing models across heterogeneous tasks,we propose Abel-Net,an Aggregated Bilateral Edge Localization Network designed as a universal framework formulti-task binary segmentation.Abel-Net integrates global and local contextual cues to enhance feature learning and edge precision.Specifically,amulti-scale feature pyramid fusion strategy is implemented via anAggregated Skip Connection(ASC)module to strengthen feature adaptability,while the Edge Dual Localization(EDL)mechanism performs coarse-to-fine refinement through edge-aware supervision.Additionally,Edge Attention(EA)and Edge Fusion Attention(EFA)modules prioritize edge-critical regions and facilitate accurate boundary alignment.Extensive experiments on nine diverse binary segmentation tasks demonstrate thatAbel-Net performs comparably to or surpasses state-of-the-art task-specific networks,exhibiting strong adaptability to a wide range of visual perception challenges.展开更多
基金supported by the National Natural Science Foundation of China(No.62276204)the Fundamental Research Funds for the Central Universities,China(No.YJSJ24011)+1 种基金the Natural Science Basic Research Program of Shaanxi,China(Nos.2022JM-340 and 2023-JC-QN-0710)the China Postdoctoral Science Foundation(Nos.2020T130494 and 2018M633470)。
文摘Visible and infrared(RGB-IR)fusion object detection plays an important role in security,disaster relief,etc.In recent years,deep-learning-based RGB-IR fusion detection methods have been developing rapidly,but still struggle to deal with the complex and changing scenarios captured by drones,mainly due to two reasons:(A)RGB-IR fusion detectors are susceptible to inferior inputs that degrade performance and stability.(B)RGB-IR fusion detectors are susceptible to redundant features that reduce accuracy and efficiency.In this paper,an innovative RGB-IR fusion detection framework based on global-local feature optimization,named GLFDet,is proposed to improve the detection performance and efficiency of drone-captured objects.The key components of GLFDet include a Global Feature Optimization(GFO)module,a Local Feature Optimization(LFO)module and a Channel Separation Fusion(CSF)module.Specifically,GFO calculates the information content of the input image from the frequency domain and optimizes the features holistically.Then,LFO dynamically selects high-value features and filters out low-value features before fusion,which significantly improves the efficiency of fusion.Finally,CSF fuses the RGB and IR features across the corresponding channels,which avoids the rearrangement of the channel relationships and enhances the model stability.Extensive experimental results show that the proposed method achieves the best performance on three popular RGB-IR datasets Drone Vehicle,VEDAI,and LLVIP.In addition,GLFDet is more lightweight than other comparable models,making it more appealing to edge devices such as drones.The code is available at https://github.com/lao chen330/GLFDet.
文摘Background and Objectives:The perception of sound in the vertical plane supports spatial hearing by enabling listeners to detect sources located above and below.Sounds originating from both the front and back elevations along the mid-sagittal plane further contribute to a three-dimensional auditory experience.This study aimed to characterize the variability in vertical sound localization abilities among normal-hearing(NH)individuals using spatialized audio.Materials and Methods:Fifty-one NH participants(aged 18 to 35 years)completed three vertical localization tasks under headphones as part of a single-group,within-subject experimental study.These tasks included two-plane identification:(1)top-down localization,(2)front-back localization,and one discrimination task in the front plane.Hierarchical Cluster Analysis(HCA)was employed to identify distinct patterns in spatial localization profiles specific to the vertical-median plane.Fisher's Discriminant Function Analysis(FDA)was used to validate the accuracy of HCA and estimate classification error.Results:HCA revealed three distinct listener clusters:(1)cluster 1 with good performance across all three tasks,(2)cluster 2 with selective impairment in top-bottom identification,and(3)cluster 3 with selective deficits in front-back identification.FDA validated group membership of the clusters identified by the HCA,with a prediction accuracy of 98%.Conclusions:Individuals with clinically NH exhibited three distinct vertical localization profiles:uniform performers,those impaired in top-bottom identification,and those impaired in front-back identification.These profiles may be linked to the interplay between acoustic and non-acoustic perceptual factors.
基金supported by the Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City(2021JJLH0058)the National Key Research and Development Program of China(2020YFA0715000)+4 种基金the Key Research and Development Program of Hubei Province(2023DJC208)the Guangdong Basic and Applied Basic Research Foundation(2021B1515120041)the Fundamental Research Funds for the Central Universities(223159006)ATR-FTIR tests were performed at the Center for Materials Research and Testing of Wuhan University of Technology(WUT)The authors would like to thank Shiyanjia Lab(www.shiyanjia.com)for the support of SEM tests.
文摘Polyaniline(PANI)exhibits remarkable electrical conductivity and mechanical flexibility,rendering it widely applicable in flexible electronic devices.For instance,it serves as a channel layer material in Organic Electrochemical Transistors(OECTs).In OECTs,the conductivity of the channel layer plays a pivotal role in dictating the switching speed and current-carrying capacity of the device.Proton acid doping represents an efficacious approach to enhancing the conductivity of polymers.However,the efficiency of direct doping of protic acid is low,thereby imposing limitations on the conductivity of polyaniline.In this study,ultrafast photoexcitation was implemented to efficiently improve the conductivity of camphor sulfonic acid(CSA)doped PANI films.Upon reaching a laser fluence of 166.2 mJ cm^(-2),the conductivity of PANI films experienced a remarkable increment of nearly four orders of magnitude,soaring to 117.6 S m^(-1),while its sheet resistance decreased to 170.9Ωsq^(-1).Meanwhile,fs-laser-treated PANI-CSA films exhibited excellent stability.The PANI-based OECT device was prepared,and the transconductance escalated from 0.113 to 0.503 mS,representing an increase exceeding fourfold.Our work provides a simple,eco-friendly,and sustainable processing technology for the preparation of high-performance PANI flexible conductive films,showing great application potential for flexible electronic devices.
文摘Proton exchange membrane(PEM)is an integral component in fuel cells which enables proton transport for efficient energy conversion.Sulfonated Polyether Ether Ketone(SPEEK)has emerged as a cost-effective option with non-fluorinated aromatic backbones for Proton Exchange Membrane Fuel Cell(PEMFC)applications,even though it exhibits lower proton conductivity compared to Nafion.This work aims to study the influence of Sulfonated Chitosan(SCS)concentrations on proton conductivity of SPEEK-based PEM at room temperature.SPEEK was synthesized using a sulfonation process with concentrated sulfuric acid at room temperature.SCS was synthesized via reflux of CS and 1.2 M H2SO4 with a ratio of 1:35(w/v)at 90℃ for 30 min.The composite membranes of SPEEK-SCS were formed with four different SCS concentrations,using the solution castingmethod,andDimethyl Sulfoxide(DMSO)was used as a solvent.The composite membranes synthesized include pure SPEEK(S0),SPEEK with 1%SCS(S1),SPEEK with 2%SCS(S2),and SPEEK with 3%SCS(S3).Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD),water uptake,degree of swelling,Ionic exchange capacity(IEC)with Electrochemical impedance spectroscopy(EIS)were used to characterize the composite membranes in terms of composition,crystallinity,water absorption,dimensional changes,number of exchangeable ions in membranes,and proton conductivity,respectively.Notably,S3 had the highest water uptake and the lowest degree of swelling.S2 had the highest proton conductivity among the SPEEK-SCS composite membranes at room temperature with 3.44×10^(−2) Scm^(-1).
基金financial supports of the National Natural Science Foundation of China(52222512)。
文摘The application potential of tuning two-dimensional materials(2DMs)characteristics through strain engineering for wearable and flexible devices has been widely recognized.However,the challenges lie in achieving accurate deterministic positioning,spatial modulation,controllable magnitude,and permanent nanostrains.Herein,motivated by the skin swelling caused by mosquito bites,a technique utilizing the heated nanotip in atomic force microscopy for thermomechanical nanoindentation is demonstrated.This method enables precise positioning of localized nanostrain and regulation of bandgap in tungsten diselenide(WSe_(2))/molybdenum disulfide(MoS_(2))heterobilayer transferred onto a flexible polymethyl methacrylate film.The magnitude of strain in the WSe_(2)/MoS_(2) heterobilayer can be controlled by adjusting the parameters of nanoindentation,leading to a spatially modulated average strain of up to 2.5%on the ring-shaped expansion structure(RES).The local bandgap of the WSe_(2)/MoS_(2) heterobilayer is spatially regulated through three distinct regions.In particular,the RES exhibits the largest extent of bandgap modulation,accompanied by a significant change of~12 meV.The nanostrain significantly enhances the photoresponse speed of the photodetector device.For instance,under illumination from a 405 nm wavelength-laser,the rise time and fall time are reduced by 75%and 87.52%,respectively,compared to the device without strain.Similarly,under illumination from a 532 nm wavelength-laser,the rise time and fall time are reduced by 66.67%and 80.60%,respectively.These findings demonstrate that the proposed method serves as a versatile way for improving the photoresponse of optoelectronic devices based on 2DMs.
基金the support from the National Natural Science Foundation of China(52473083,52373089,52403085)Natural Science Basic Research Program of Shaanxi(2024JC-TBZC-04)+2 种基金the Innovation Capability Support Program of Shaanxi(2024RS-CXTD-57)Natural Science Basic Research Plan in Shaanxi Province of China(2024JC-YBMS-279)Natural Science Foundation of Chongqing,China(2023NSCQMSX2547)
文摘With the miniaturization and high-frequency evolution of antennas in 5G/6G communications,aerospace,and transportation,polymer composite papers integrating superior wave-transparent performance and thermal conductivity for radar antenna systems are urgently needed.Herein,a down-top strategy was employed to synthesize poly(p-phenylene benzobisoxazole)precursor nanofibers(prePNF).The prePNF was then uniformly mixed with fluorinated graphene(FG)to fabricate FG/PNF composite papers through consecutively suction filtration,hot-pressing,and thermal annealing.The hydroxyl and amino groups in prePNF enhanced the stability of FG/prePNF dispersion,while the increasedπ-πinteractions between PNF and FG after annealing improved their compatibility.The preparation time and cost of PNF paper was significantly reduced when applying this strategy,which enabled its large-scale production.Furthermore,the prepared FG/PNF composite papers exhibited excellent wave-transparent performance and thermal conductivity.When the mass fraction of FG was 40 wt%,the FG/PNF composite paper prepared via the down-top strategy achieved the wave-transparent coefficient(|T|2)of 96.3%under 10 GHz,in-plane thermal conductivity(λ_(∥))of 7.13 W m^(−1)K^(−1),and through-plane thermal conductivity(λ_(⊥))of 0.67 W m^(−1)K^(−1),outperforming FG/PNF composite paper prepared by the top-down strategy(|T|2=95.9%,λ_(∥)=5.52 W m^(−1)K^(−1),λ_(⊥)=0.52 W m^(−1)K^(−1))and pure PNF paper(|T|2=94.7%,λ_(∥)=3.04 W m^(−1)K^(−1),λ_(⊥)=0.24 W m^(−1)K^(−1)).Meanwhile,FG/PNF composite paper(with 40 wt%FG)through the down-top strategy also demonstrated outstanding mechanical properties with tensile strength and toughness reaching 197.4 MPa and 11.6 MJ m^(−3),respectively.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(2021R1A6A1A10044950).
文摘The thermal conductivity of nanofluids is an important property that influences the heat transfer capabilities of nanofluids.Researchers rely on experimental investigations to explore nanofluid properties,as it is a necessary step before their practical application.As these investigations are time and resource-consuming undertakings,an effective prediction model can significantly improve the efficiency of research operations.In this work,an Artificial Neural Network(ANN)model is developed to predict the thermal conductivity of metal oxide water-based nanofluid.For this,a comprehensive set of 691 data points was collected from the literature.This dataset is split into training(70%),validation(15%),and testing(15%)and used to train the ANN model.The developed model is a backpropagation artificial neural network with a 4–12–1 architecture.The performance of the developed model shows high accuracy with R values above 0.90 and rapid convergence.It shows that the developed ANN model accurately predicts the thermal conductivity of nanofluids.
基金funding for this research comes fromHubei Provincial Natural Science Foundation(2022CFB690)the Open Foundation(UOG2024-03)of Cooperative Innovation Center of Unconventional Oil+1 种基金Gas,Yangtze University(Ministry of Education&Hubei Province)and the Open Foundation(YQZC202302)of Hubei Key Laboratory of Oil and Gas Drilling and Production Engineering(Yangtze University)the National Natural Science Foundation of China(Grant no.U23B20156).
文摘To investigate the long-term fracture conductivity behavior of propped fractures under the high-temperature and high-pressure conditions of deep shale gas reservoirs in the Sichuan Basin,this study systematically analyzed the effects of closure stress,proppant concentration,formation temperature,and proppant size combination.Conductivity experiments were conducted using the HXDL-2C long-term proppant conductivity evaluation system under simulated reservoir conditions to determine the time-dependent evolution of fracture conductivity.The results showed that the 50-h conductivity retention of the rock-plate experiments ranged from 22%to 28%.With increasing closure stress,fracture conductivity exhibited a rapid decline.Under a formation temperature of 120℃ and a proppant concentration of 5 kg·m^(-2),the short-term conductivity of 70/140 mesh quartz-sand-propped fractures was 2.37μm^(2)·cm,which decreased to 0.66μm^(2)·cm after long-term testing.When the closure stress increased to 80 MPa,the short-term and long-term conductivities further declined to 1.36μm^(2)·cm and 0.39μm^(2)·cm,respectively.Increasing the proppant concentration from 5 to 7.5 kg·m^(-2)at 120℃ and 80 MPa improved both short-term and long-term conductivities by enlarging the effective fracture width;however,the conductivity decay rate accelerated,and the 50-h retention dropped from 27.2%to 22.8%.Raising the temperature from 120℃ to 140℃ promoted proppant crushing and compaction,intensified shale creep,and accelerated fracture closure,reducing long-term conductivity from 0.37 to 0.30μm^(2)·cm.Under identical conditions,40/70 mesh ceramic proppants maintained significantly higher conductivities than 70/140 mesh quartz sand,with short-term and long-term values of 8.71 and 2.19μm^(2)·cm,respectively,at 120℃,80 MPa,and 5 kg·m^(-2).Pure quartz-sand systems failed to maintain effective conductivity under high-temperature and high-stress conditions,whereas adding 20%40/70 mesh ceramic proppant and thoroughly mixing it,the long-term conductivity has increased by 2.3 times,improving fracture stability while reducing overall cost.A predictive equation was derived from the experimental results to capture the dynamic decay characteristics of fracture conductivity.These outcomes provide a valuable experimental basis and technical support for optimizing fracturing fluid design,proppant selection,and operation parameters in deep shale formations.
基金supported by the National Natural Science Foundation of China(12401279,12371219)the Academic and Technical Leaders Training Plan of Jiangxi Province(20212BCJ23027).
文摘This paper is concerned with an initial boundary value problem for the planar magnetohydrodynamic compressible flow with temperature dependent heat conductivity in a half-line.In particular,the transverse magnetic field is assumed to satisfy the Neumann boundary condition,which was first investigated by Kazhikhov in 1987.We establish the global existence of the unique strong solutions to the MHD equations without any smallness conditions on the initial data.More precisely,our result can be regarded as a natural generalization of Kazhikov’s result for applying the constant heat-conductivity in bounded domains to the degenerate case in unbounded domains.
文摘Conducting hydrogels have garnered significant interest in the field of wearable electronics.However,simultaneously achieving high transparency,high conductivity,strong adhesion,and self-healing ability within a short time remains a major challenge.In this study,a multifunctional mussel-inspired hydrogel was synthesized in only 5 min,with polydopamine(PDA)-polypyrrole(Ppy)-polyaniline(PANi)and poly(vinyl alcohol)(PVA)nanoparticles incorporated into the polyacrylamide(PAM)network.The resulting hydrogel exhibited high transparency(about 90% light transmission in the range of 400-800 nm),high conductivity((95.4±0.4)×10^(-4)S/cm),tensile strength(32.60±1.03 k Pa),strain at break(904.46%±11.50%),and adhesive strength(30-60 k Pa).It also demonstrated rapid self-healing properties(about 48% strength recovery within 1h at 50℃)and water-dependent shape memory behavior.As a wearable strain sensor,the hydrogel successfully detected finger flexion,wrist movements,facial expression changes,and breathing with high sensitivity and stability.The calculated gauge factor(GF)was 7.44±0.31,which is higher than that of many previously reported hydrogels.Compared with previous oyster-inspired or Ppy-based hydrogels,our system showed a much shorter synthesis time,higher transparency,and enhanced multifunctionality.These findings highlight the potential of the proposed hydrogel for next-generation flexible electronics,e-skin,and biomedical monitoring devices.
基金financially supported by National Natural Science Foundation of China(No.52175321)the Fund of Key Laboratory of High Temperature Electromagnetic Materials and Structure of MOE(No.KB202505)。
文摘There is an urgent need to develop magnesium-matrix materials that exhibit both high thermal conductivity and low thermal expansion to ensure compatibility with chips.This study aims to develop a Mg-Zn-Cu alloy with high thermal conductivity.Furthermore,it explores the preparation of AlN_(P)/Mg-Zn-Cu composites featuring low coefficients of thermal expansion.The stir casting method was utilized to fabricate the composites and an investigation was conducted to examine their microstructure and thermal properties.Results indicate that the addition of AlN_(P)reduces the thermal expansion coefficient while maintaining relatively high thermal conductivity.Specifically,the AlN_(P)/Mg-0.5Zn-0.5Cu composite with 30wt.%AlN_(P)achieves a thermal conductivity of 132.7 W·m^(-1)·K^(-1)and a thermal expansion coefficient of 18.5×10^(-6)K^(-1),rendering it suitable for electronic packaging applications where thermal management is critical.
基金funded by Ministry of Higher Education Malaysia through Universiti Malaysia Pahang Al-Sultan Abdullah under Internal Research Grant(RDU233003).
文摘This paper proposes a tamper detection technique for semi-fragile watermarking using Quantizationbased Discrete Cosine Transform(DCT)for tamper localization.In this study,the proposed embedding strategy is investigated by experimental tests over the diagonal order of the DCT coefficients.The cover image is divided into non-overlapping blocks of size 8×8 pixels.The DCT is applied to each block,and the coefficients are arranged using a zig-zag pattern within the block.In this study,the low-frequency coefficients are selected to examine the impact of the imperceptibility score and tamper detection accuracy.High accuracy of tamper detection can be achieved by checking the surrounding blocks to determine whether the corresponding block has been tampered with.The proposed tamper detection is tested under various malicious,incidental,and hybrid attacks(both incidental and malicious attacks).The experimental results demonstrate that the proposed technique achieves a Peak-Signal-to-Noise Ratio(PSNR)value of 41.2318 dB,an average Structural Similarity Index Measure(SSIM)value of 0.9768.The proposed scheme is also evaluated against malicious attacks such as copy-move,object deletion,object manipulation,and collage attacks.The proposed scheme can detect the malicious attack localization under various tampering rates.In addition,the proposed scheme can still detect tampered pixels under a hybrid attack,such as a combination ofmalicious and incidental attacks,with an average accuracy of 96.44%.
基金National Key R&D Program of China under Grants 2021YFB2900404the National Natural Science Foundation of China under Grants 62371098。
文摘The acquisition of position information of legitimate users and jammers plays an important role in the emerging non-geostationary synchronous orbit(NGSO)satellite communications.In this paper,we study the multi-signal localization problem in an uplink NGSO satellite communication system.We propose an onboard localization scheme based on multiple observations from the satellite,together with the geometric constraints of the satellite postions,the signal positions,the attitude of the satellite,and the angle-of-arrival(AoAs)of the signals.We develop a massage-passing algorithm,termed the Bayesian blind multi-signal localization(BMSL),to jointly estimate the AoAs and the signal positions.The Cramér-Rao lower bound(CRLB)is derived to characterize the fundamental performance limit of the considered localization problem.Simulation results show that the proposed BMSL algorithm can perform close to the derived CRLB and significantly outperforms its counterpart algorithms.
基金financially supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(No.NRF-2020R1A3B2079803 and No.RS-2024-00453815),Republic of Korea。
文摘Localized high-concentration electrolytes(LHCEs)are considered as promising electrolyte candidates to resolve technical issues of metal batteries owing to their unique interfacial properties and solvation structures.Herein,we propose a self-assembly chemical strategy into the LCHEs induced by ordered nanostructure of zwitterionic co-solutes for highly efficient and ultrastable zinc(Zn)metal batteries.Through the systematic screening of six zwitterionic compounds,3-(decyldimethylammonio)propanesulfonate salt(C_(10))with the decyl chain and zwitterions was determined as an optimum to construct quasi-spherical aggregates with a periodic length of 3.77 nm,as confirmed by comprehensive synchronous small-angle X-ray scattering,Guinier,pair distance distribution function,Porod,and other spectroscopic characterizations and molecular dynamic simulation.In particularly,this self-assembled structure in electrolyte environments was attributed to increasing the proportion of both contact and aggregated ion pairs for the formation of LHCEs as well as to providing fast and selective Zn^(2+)conducting channels and uniform solid electrolyte interfaces for facilitated charge transfer kinetics.Moreover,the preferential adsorption of the self-assembled C_(10)on the Zn(002)surface modulated the electrical double layer to suppress hydrogen evolution and corrosion reactions.Consequently,the Zn‖Zn symmetric cells in Zn(OTf)_(2)/C_(10)electrolytes showed long-term plating/stripping behaviors over 2800 h at 1 mA cm^(-2)and 1 mAh cm^(-2)as well as over 1200 h even at 5 mA cm^(-2)and 5 mAh cm^(-2)with a very high depth of discharge of 42.7%.Furthermore,the ZnllVO_(2)/CNT full cells in Zn(OTf)_(2)/C_(10)electrolytes delivered a record-high capacity of 8.10 mAh cm^(-2)at an ultrahigh cathode mass loading of 50 mg cm^(-2)after 150 cycles.
基金Project supported by the National Natural Science Foundation of China(No.12472062)。
文摘In this paper,a theoretical model is established for locally resonant plates with general resonators,and the corresponding governing equation is derived.The model provides a mathematical demonstration of the locally resonant effect,which contains two parts:the first part is induced by translation coupling,and the second part is induced by rotation coupling.The second part cannot be reflected by most existing theoretical models.The analytical solutions of the dynamic response are compared with the direct numerical simulation(DNS)results for two locally resonant plates with different resonator types,thereby validating the general applicability of the present model.The rotation coupling effect leads to the frequency-dependent effective rotational inertia density and anisotropic dispersion relation of the locally resonant plate,as well as the enhancement of the structural vibration suppression ability.
基金supported in part by the National Natural Science Foundation of China under Grant 52432012in part by the Shanghai Science and Technology Project with 25ZR1402508。
文摘The stator of the maglev track plays a crucial role in the operation of the maglev system.Currently,the efficiency of maglev track inspection is limited by several factors,including the large span of elevated structures,manual visual inspection,short inspection window times,and limited GPS positioning accuracy.To address these issues,this paper proposes a deep learning-based method for detecting and locating stator surface damage.This study establishes a maglev track stator surface image dataset,trains different object detection models,and compares their performance.Ultimately,YOLO and ByteTrack object tracking algorithms were chosen as the basic framework and enhanced to achieve automatic identification of high-speed maglev track stator surface damage images and track and count stator surface localization feature images.By matching the identified damaged images with their corresponding stator segment and beam segment sequence numbers,the location of the damage is pinpointed to the corresponding stator segment,enabling rapid and accurate identification and localization of complex damage to the maglev track stator surface.
基金Princess Nourah bint Abdulrahman University Researchers Supporting Project number(PNURSP2025R8)。
文摘In this article,we introduce a new theoretical approach to improve the accuracy of twodimensional(2D)atomic localization within a tripod-type,four-level atomic system by analyzing its transmission spectrum.In this method,the atom interacts with two orthogonal standing-wave fields and a weak probe field.By examining how the weak probe field passes through the system,we can determine the atom position.Our analysis reveals the presence of both double and sharply defined single localized peaks in the transmission spectrum,which correspond to specific positions of the atom.Importantly,we achieve ultra-high-resolution atomic localization with accuracy confined to a region smaller thanλ/32×λ/32.This level of precision is a significant improvement compared to earlier methods,which had lower localization accuracy.The increased precision is due to the complex interaction between the atom and the carefully controlled standing-wave and probe fields,which allows for precise control over the atom's position.The implications of this work are significant,especially for applications like nano-lithography,where precise atomic placement is essential,and for laser cooling technologies,where better atomic localization could lead to more effective cooling processes and improved manipulation of atomic states.
基金National Science Fund for Distinguished Young Scholars,Grant/Award Number:52225403State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering,Grant/Award Number:SDGZK2404Fundamental Research Funds for the Central Universities,Grant/Award Number:2023KYJD1006。
文摘Hydrochloric acid(HCl)extensively exists in deep underground projects,arising from the transportation of industrial raw materials or fracturing fluids of petroleum engineering.It results in corrosion,which can significantly impact the stability of surrounding rock structures.Therefore,in-depth analysis of the degradation of rock corroded by the HCl solution is an essential task for underground engineering.In this study,the granite specimens are initially treated with the HCl solution with various concentrations.Then,the tests and analyses,such as electrical conductivity(EC)measurements,mineral composition assays,and Brazilian splitting tests,are employed to investigate the corrosion mechanism of the HCl solution.Our results and findings are generally as follows:(1)As the immersion time increases,the EC exhibits a relatively high level at pH value of 1,a decreasing trend at pH value of 3,and an increasing trend at pH value of 5 and 7.(2)The HCl solutions with various concentration have different effect on mineral composition,characterized by an increase in proportion of SiO_(2) and a reduction in proportion of Na_(2)O,Al_(2)O_(3),K_(2)O,MgO,and CaO,as the solution pH value decreases.(3)After immersion in the solutions with pH values of 1,3,and 5,the tensile strength of the granite decreases by 23.85%,20.84%,and 20.24%;the average stiffness of the specimen decreases by 29.29%,23.43%,and 11.97%;the proportion of releasable energy increases by 6%,4%,and -2%;the releasable energy decreases by 54.96%,26.09%,and 14.52%;and the dissipated energy decreases by approximately 68.85%,41.39%,and 5.41%,respectively.(4)The evolution of physical and mechanical properties of the immersed granite specimen can be analyzed from a chemical aspect.The corrosive action of HCl cleaves Si–O and Al–O chemical bonds within the granite,particularly altering the tetrahedral structures of its silicate components.This process involves breaking existing chemical bonds and the formation of new ones,ultimately destroying the silicate molecular structures.As the concentration of HCl increases,the rate of these reactions accelerates,progressively weakening the chemical bonds and consequently deteriorating the mechanical characteristics of the granite.These findings can deepen our knowledge about the corrosion effect of HCI solutions on natural surrounding rocks and serve as references for further research on rock corrosion mechanisms in underground engineering.
基金supported by the National Natural Science Foundation of China under Grant 62206083.
文摘Binary segmentation tasks in computer vision exhibit diverse appearance distributions and complex boundary characteristics.To address the limited generalization and adaptability of existing models across heterogeneous tasks,we propose Abel-Net,an Aggregated Bilateral Edge Localization Network designed as a universal framework formulti-task binary segmentation.Abel-Net integrates global and local contextual cues to enhance feature learning and edge precision.Specifically,amulti-scale feature pyramid fusion strategy is implemented via anAggregated Skip Connection(ASC)module to strengthen feature adaptability,while the Edge Dual Localization(EDL)mechanism performs coarse-to-fine refinement through edge-aware supervision.Additionally,Edge Attention(EA)and Edge Fusion Attention(EFA)modules prioritize edge-critical regions and facilitate accurate boundary alignment.Extensive experiments on nine diverse binary segmentation tasks demonstrate thatAbel-Net performs comparably to or surpasses state-of-the-art task-specific networks,exhibiting strong adaptability to a wide range of visual perception challenges.
