INTRODUCTION.On January 7,2025,at 9:05 AM BJT,a MS6.8 earthquake(CENC epicenter:28.50°N,87.45°E)struck Dingri County,Xizang Province(hereinafter referred to as the Dingri mainshock).The inferred moment magni...INTRODUCTION.On January 7,2025,at 9:05 AM BJT,a MS6.8 earthquake(CENC epicenter:28.50°N,87.45°E)struck Dingri County,Xizang Province(hereinafter referred to as the Dingri mainshock).The inferred moment magnitude,based on regional/teleseismic waveform inversion and back-projection,is approximately MW7.1.Focal mechanism solutions,aftershock distribution,and field surveys indicate that the Dingri mainshock was a normal-faulting event,with a nearly north-south strike and a westward-dipping fault plane.展开更多
This study aimed to investigate the moment redistribution in continuous glass fiber reinforced polymer(GFRP)-concrete composite slabs caused by concrete cracking and steel bar yielding in the negative bending moment z...This study aimed to investigate the moment redistribution in continuous glass fiber reinforced polymer(GFRP)-concrete composite slabs caused by concrete cracking and steel bar yielding in the negative bending moment zone.An experimental bending moment redistribution test was conducted on continuous GFRP-concrete composite slabs,and a calculation method based on the conjugate beam method was proposed.The composite slabs were formed by combining GFRP profiles with a concrete layer and supported on steel beams to create two-span continuous composite slab specimens.Two methods,epoxy resin bonding,and stud connection,were used to connect the composite slabs with the steel beams.The experimental findings showed that the specimen connected with epoxy resin exhibited two moments redistribution phenomena during the loading process:concrete cracking and steel bar yielding at the internal support.In contrast,the composite slab connected with steel beams by studs exhibited only one-moment redistribution phenomenon throughout the loading process.As the concrete at the internal support cracked,the bending moment decreased in the internal support section and increased in the midspan section.When the steel bars yielded,the bending moment further decreased in the internal support section and increased in the mid-span section.Since GFRP profiles do not experience cracking,there was no significant decrease in the bending moment of the mid-span section.All test specimens experienced compressive failure of concrete at the mid-span section.Calculation results showed good agreement between the calculated and experimental values of bending moments in the mid-span section and internal support section.The proposed model can effectively predict the moment redistribution behavior of continuous GFRP-concrete composite slabs.展开更多
To further understand the performance of the energy harvesters under the influence of the wind force and the random excitation,this paper investigates the stochastic response of the bio-inspired energy harvesters subj...To further understand the performance of the energy harvesters under the influence of the wind force and the random excitation,this paper investigates the stochastic response of the bio-inspired energy harvesters subjected to Gaussian white noise and galloping excitation,simulating the flapping pattern of a seagull and its interaction with wind force.The equivalent linearization method is utilized to convert the original nonlinear model into the Itôstochastic differential equation by minimizing the mean squared error.Then,the second-order steady-state moments about the displacement,velocity,and voltage are derived by combining the moment analysis theory.The theoretical results are simulated numerically to analyze the stochastic response performance under different noise intensities,wind speeds,stiffness coefficients,and electromechanical coupling coefficients,time domain analysis is also conducted to study the performance of the harvester with different parameters.The results reveal that the mean square displacement and voltage increase with increasing the noise intensity and wind speed,larger absolute values of stiffness coefficient correspond to smaller mean square displacement and voltage,and larger electromechanical coupling coefficients can enhance the mean square voltage.Finally,the influence of wind speed and electromechanical coupling coefficient on the stationary probability density function(SPDF)is investigated,revealing the existence of a bimodal distribution under varying environmental conditions.展开更多
In this paper,we introduce the real pairwise completely positive(RPCP)matrices with one of them is necessarily positive semidefinite while the other one is necessarily entrywise nonnegative,which has a real pairwise c...In this paper,we introduce the real pairwise completely positive(RPCP)matrices with one of them is necessarily positive semidefinite while the other one is necessarily entrywise nonnegative,which has a real pairwise completely positive(RPCP)decomposition.We study the properties of RPCP matrices and give some necessary and sufficient conditions for a matrix pair to be RPCP.First,we give an equivalent decomposition for the RPCP matrices,which is different from the RPCP-decomposition and show that the matrix pair(X,X)is RPCP if and only if X is completely positive.Besides,we also prove that the RPCP matrices checking problem is equivalent to the separable completion problem.A semidefinite algorithm is also proposed for detecting whether or not a matrix pair is RPCP.The asymptotic and finite convergence of the algorithm are also discussed.If it is RPCP,we can further give a RPCP-decomposition for it;if it is not,we can obtain a certificate for this.展开更多
Beyond business,the CIIE is a vibrant platform where diverse cultures meet,share,and shine The eighth China International Import Expo,held from 5 to 10 November in Shanghai,once again served as a premier stage for exh...Beyond business,the CIIE is a vibrant platform where diverse cultures meet,share,and shine The eighth China International Import Expo,held from 5 to 10 November in Shanghai,once again served as a premier stage for exhibitors from around the world to showcase their distinctive cultures.From food and clothing to a wide array of arts,the more than 900,000 visitors were treated to a rich tapestry of cultural experiences from across the globe.展开更多
Powered fight in birds is reliant on feathers forming an aerodynamic surface that resists air pressures.Many basic aspects of feather functionality are unknown,which hampers our understanding of wing function in birds...Powered fight in birds is reliant on feathers forming an aerodynamic surface that resists air pressures.Many basic aspects of feather functionality are unknown,which hampers our understanding of wing function in birds.This study measured the dimensions of primary and secondaryfight feathers of 19 species of parrots.The maximum force the feathers could withstand from below was also measured to mimic the pressuresexperienced during a downstroke.The analysis tested whether:(1)feather dimensions differed along the wing and among secondary and primary remiges;(2)the force that feathers could withstand varied among the remiges;and(3)there would be isometric relationships with bodymass for feather characteristics.The results show that body mass signifcantly affected vane width,rachis thickness,maximum force,and ultimate bending moment,but the relationship for feather length only approached signifcance.Many of the proximal secondary feathers showedsignifcantly lower values relative to the frst primary,whereas for distal primaries the values were greater.There were isometric relationships forforce measurements of primary and secondary feathers with body mass,but there was positive allometry for feather lengths and vane widths.The forces feathers can withstand vary along the wing may be a proxy for the aerodynamic properties of the feathers in situ.Broader taxonomicstudies that explore these topics are required for other species representing a range of different orders.A better understanding of the functionality of feathers will improve our understanding of how avian fight works particularly considering the variety in fight style and wing shape in birds.展开更多
This paper proposed a moment tensor regression prediction technology based on ResNet for microseismic events.Taking the great advantages of deep networks in classification and regression tasks,it can realize the great...This paper proposed a moment tensor regression prediction technology based on ResNet for microseismic events.Taking the great advantages of deep networks in classification and regression tasks,it can realize the great potential of fast and accurate inversion of microseismic moment tensors after the network trained.This ResNet-based moment tensor prediction technology,whose input is raw recordings,does not require the extraction of data features in advance.First,we tested the network using synthetic data and performed a quantitative assessment of the errors.The results demonstrate that the network exhibits high accuracy and efficiency during the prediction phase.Next,we tested the network using real microseismic data and compared the results with those from traditional inversion methods.The error in the results was relatively small compared to traditional methods.However,the network operates more efficiently without requiring manual intervention,making it highly valuable for near-real-time monitoring applications.展开更多
This paper employs Granger causality analysis and the generalized impulse response function(GIRF)to study the higher-order moment spillover effects among Bitcoin,stock markets,and foreign exchange markets in the U.S.U...This paper employs Granger causality analysis and the generalized impulse response function(GIRF)to study the higher-order moment spillover effects among Bitcoin,stock markets,and foreign exchange markets in the U.S.Using intraday high-frequency data,the research focuses on the interactions across higher-order moments,including volatility,jumps,skewness,and kurtosis.The results reveal significant bidirectional spillover effects between Bitcoin and traditional financial assets,particularly in terms of volatility and jump behavior,indicating that the cryptocurrency market has become a crucial component of global financial risk transmission.This study provides new theoretical perspectives and policy recommendations for global asset allocation,market regulation,and risk management,underscoring the importance of proactive management measures in addressing the complex risk interactions between cryptocurrencies and traditional financial markets.展开更多
Triggered seismicity is a key hazard where fluids are injected or withdrawn from the subsurface and may impact permeability. Understanding the mechanisms that control fluid injection-triggered seismicity allows its mi...Triggered seismicity is a key hazard where fluids are injected or withdrawn from the subsurface and may impact permeability. Understanding the mechanisms that control fluid injection-triggered seismicity allows its mitigation. Key controls on seismicity are defined in terms of fault and fracture strength, second-order frictional response and stability, and competing fluid-driven mechanisms for arrest. We desire to constrain maximum event magnitudes in triggered earthquakes by relating pre-existing critical stresses to fluid injection volume to explain why some recorded events are significantly larger than anticipated seismic moment thresholds. This formalism is consistent with several uncharacteristically large fluid injection-triggered earthquakes. Such methods of reactivating fractures and faults by hydraulic stimulation in shear or tensile fracturing are routinely used to create permeability in the subsurface. Microearthquakes (MEQs) generated by such stimulations can be used to diagnose permeability evolution. Although high-fidelity data sets are scarce, the EGS-Collab and Utah FORGE hydraulic stimulation field demonstration projects provide high-fidelity data sets that concurrently track permeability evolution and triggered seismicity. Machine learning deciphers the principal features of MEQs and the resulting permeability evolution that best track permeability changes – with transfer learning methods allowing robust predictions across multiple eological settings. Changes in permeability at reactivated fractures in both shear and extensional modes suggest that permeability change (Δk) scales with the seismic moment (M) of individual MEQs as Δk∝M. This scaling relation is exact at early times but degrades with successive MEQs, but provides a method for characterizing crustal permeability evolution using MEQs, alone. Importantly, we quantify for the first time the role of prestress in defining the elevated magnitude and seismic moment of fluid injection-triggered events, and demonstrate that such MEQs can also be used as diagnostic in quantifying permeability evolution in the crust.展开更多
A new polarization–interference biomedical diagnostic three-dimensional(3D)Jones-matrix technology with digital Fourier reconstruction of layered maps of optical anisotropy(thesiograms)of dehydrated films(facies)of b...A new polarization–interference biomedical diagnostic three-dimensional(3D)Jones-matrix technology with digital Fourier reconstruction of layered maps of optical anisotropy(thesiograms)of dehydrated films(facies)of biological fluids of human organs is presented and experimentally tested.An original model of layered phase scanning of polycrystalline architectonics of supramolecular networks of biological fluid facies is proposed for the purpose of theoretical justification and prognostic use of the obtained results.On its basis,algorithms of Jones-matrix reconstruction of thesiograms of birefringence and dichroism of facies of synovial fluid,bile and blood are found.As a result,layered thesiograms of linear and circular birefringence and dichroism of facies with different spatial–angular architectonics of supramolecular networks are experimentally obtained for the first time.Within the framework of statistical analysis of experimental data,new objective markers(asymmetry and excess of optical anisotropy parameter distributions)for diagnostics of pathological changes in the optical anisotropy of biological fluid facies were defined and clinically tested.As a result,an excellent level of balanced accuracy of the developed polarization–interference Jones-matrix method of layer-by-layer reconstruction of thesiograms of polycrystalline supramolecular networks in differential diagnostics of bile facies(cholelithiasis),synovial fluid(reactive synovitis–septic arthritis)and whole blood(follicular adenoma–papillary thyroid cancer)was achieved.展开更多
As urban landscapes evolve and vehicular volumes soar,traditional traffic monitoring systems struggle to scale,often failing under the complexities of dense,dynamic,and occluded environments.This paper introduces a no...As urban landscapes evolve and vehicular volumes soar,traditional traffic monitoring systems struggle to scale,often failing under the complexities of dense,dynamic,and occluded environments.This paper introduces a novel,unified deep learning framework for vehicle detection,tracking,counting,and classification in aerial imagery designed explicitly for modern smart city infrastructure demands.Our approach begins with adaptive histogram equalization to optimize aerial image clarity,followed by a cutting-edge scene parsing technique using Mask2Former,enabling robust segmentation even in visually congested settings.Vehicle detection leverages the latest YOLOv11 architecture,delivering superior accuracy in aerial contexts by addressing occlusion,scale variance,and fine-grained object differentiation.We incorporate the highly efficient ByteTrack algorithm for tracking,enabling seamless identity preservation across frames.Vehicle counting is achieved through an unsupervised DBSCAN-based method,ensuring adaptability to varying traffic densities.We further introduce a hybrid feature extraction module combining Convolutional Neural Networks(CNNs)with Zernike Moments,capturing both deep semantic and geometric signatures of vehicles.The final classification is powered by NASNet,a neural architecture search-optimized model,ensuring high accuracy across diverse vehicle types and orientations.Extensive evaluations of the VAID benchmark dataset demonstrate the system’s outstanding performance,achieving 96%detection,94%tracking,and 96.4%classification accuracy.On the UAVDT dataset,the system attains 95%detection,93%tracking,and 95%classification accuracy,confirming its robustness across diverse aerial traffic scenarios.These results establish new benchmarks in aerial traffic analysis and validate the framework’s scalability,making it a powerful and adaptable solution for next-generation intelligent transportation systems and urban surveillance.展开更多
In this paper,an image processing algorithm which is able to synthesize material textures of arbitrary shapes is proposed.The presented approach uses an arbitrary image to construct a structure layer of the material.T...In this paper,an image processing algorithm which is able to synthesize material textures of arbitrary shapes is proposed.The presented approach uses an arbitrary image to construct a structure layer of the material.The resulting structure layer is then used to constrain the material texture synthesis.The field of second-moment matrices is used to represent the structure layer.Many tests with various constraint images are conducted to ensure that the proposed approach accurately reproduces the visual aspects of the input material sample.The results demonstrate that the proposed algorithm is able to accurately synthesize arbitrary-shaped material textures while respecting the local characteristics of the exemplar.This paves the way toward the synthesis of 3D material textures of arbitrary shapes from 2D material samples,which has a wide application range in virtual material design and materials characterization.展开更多
In this study,we employed Bayesian inversion coupled with the summation-by-parts and simultaneousapproximation-term(SBP-SAT)forward simulation method to elucidate the mechanisms behind mininginduced seismic events cau...In this study,we employed Bayesian inversion coupled with the summation-by-parts and simultaneousapproximation-term(SBP-SAT)forward simulation method to elucidate the mechanisms behind mininginduced seismic events caused by fault slip and their potential effects on rockbursts.Through Bayesian inversion,it is determined that the sources near fault FQ14 have a significant shear component.Additionally,we analyzed the stress and displacement fields of high-energy events,along with the hypocenter distribution of aftershocks,which aided in identifying the slip direction of the critically stressed fault FQ14.We also performed forward modeling to capture the complex dynamics of fault slip under varying friction laws and shear fracture modes.The selection of specific friction laws for fault slip models was based on their ability to accurately replicate observed slip behavior under various external loading conditions,thereby enhancing the applicability of our findings.Our results suggest that the slip behavior of fault FQ14 can be effectively understood by comparing different scenarios.展开更多
In the current digital context,safeguarding copyright is a major issue,particularly for architectural drawings produced by students.These works are frequently the result of innovative academic thinking combining creat...In the current digital context,safeguarding copyright is a major issue,particularly for architectural drawings produced by students.These works are frequently the result of innovative academic thinking combining creativity and technical precision.They are particularly vulnerable to the risk of illegal reproduction when disseminated in digital format.This research suggests,for the first time,an innovative approach to copyright protection by embedding a double digital watermark to address this challenge.The solution relies on a synergistic fusion of several sophisticated methods:Krawtchouk Optimized Octonion Moments(OKOM),Quaternion Singular Value Decomposition(QSVD),and Discrete Waveform Transform(DWT).To improve watermark embedding,the biologically inspired algorithm Chaos-White Shark Optimization(CWSO)is used,which allows dynamically adapting essential parameters such as the scaling factor of the insertion.Thus,two watermarks are inserted at the same time:an institutional logo and a student image,encoded in the main image(the architectural plan)through octonionic projections.This allows minimizing the amount of data to be integrated while increasing resistance.The suggested approach guarantees a perfect balance between the discreetness of the watermark(validated by PSNR indices>47 dB and SSIM>0.99)and its resistance to different attacks(JPEG compression,noise,rotation,resizing,filtering,etc.),as proven by the normalized correlation values(NC>0.9)obtained following the extraction.Therefore,this method represents a notable progress for securing academic works in architecture,providing an effective,discreet and reversible digital protection,which does not harm the visual appearance of the original works.展开更多
To effectively improve the adaptability and traversal abilities of a multi-terrain mobile robot under the dynamic excitation of multiple roads,we explore the mobile robot’s vibration and joint driving output stall ca...To effectively improve the adaptability and traversal abilities of a multi-terrain mobile robot under the dynamic excitation of multiple roads,we explore the mobile robot’s vibration and joint driving output stall caused by the dynamic excitation of the road spectrum function and analyze techniques for reducing the vibration and enhancing the driving moment of a four-wheel differential-speed mobile robot.A double-wishbone vibration reduction suspension and a moment compensator were designed for a multi-terrain mobile robot by theoretically describing its suspensionwheel-road dynamics.Also,the mobile robot’s road adaptability and traversal abilities were mathematically characterized under dynamic excitation.Co-simulation in ADAMS-MATLAB/Simulink is performed such as the harsh condition of in situ rotation and outdoor experimental schemes are implemented in which the experimental data are analyzed.The experimental result verifies the correctness of the theoretical analysis,as well as the effectiveness of the vibration reduction suspension and the moment compensator.The compatibility of the mobile robot’s driving mechanisms with road traversal abilities has been improved under various terrain conditions in complex field operation scenarios.展开更多
With the rapid development of Internet of things technology,the efficiency of data transmission between devices has been significantly improved.However,the open network environment also poses serious security risks.Th...With the rapid development of Internet of things technology,the efficiency of data transmission between devices has been significantly improved.However,the open network environment also poses serious security risks.This paper proposes an innovative fingerprint template protection scheme,which generates key streams through an improved fourdimensional superchaotic system(4CSCS),uses the space-filling property of Hilbert curves to achieve pixel scrambling,and introduces dynamic DNA encoding to improve encryption.Experimental results show that this scheme has a large key space 2^(528),encrypts image information entropy of more than 7.9970,and shows excellent performance in defending against statistical attacks and differential attacks.Compared with existing methods,this scheme has significant advantages in terms of encryption performance and security,and provides a reliable protection mechanism for fingerprint authentication systems in the Internet of things environment.展开更多
Rollover accidents involving agricultural wheeled robots,accompanied by severe mechanical impacts,pose serious threats to operational safety and reduce functional efficiency.To address this issue,an active rollover pr...Rollover accidents involving agricultural wheeled robots,accompanied by severe mechanical impacts,pose serious threats to operational safety and reduce functional efficiency.To address this issue,an active rollover prevention strategy is proposed,utilizing a single‐gimbal control moment gyro(SGCMG),to stabilize typical agricultural robots and prevent potential rollovers.To match the free oscillation of the pivot front axle,a novel recovery torque model of the coupled robot‐SGCMG system is established,in which two patterns are introduced to refine the rollover process with uncertain parameters.Additionally,a lateral stability index is adopted and analyzed to assess the hazard level of potential rollovers.Aimed at handling uncertain parameters and hazard levels,an adaptive backstepping control strategy is developed for real‐time anti‐rollover implementation.Within this strategy,control gains are adaptively tuned based on theoretical derivations,thereby suppressing rollover tendency while minimizing tuning effort.For verification,a scaled experimental platform,designed according to similarity theory,is constructed to ensure safety of personnel and equipment.Experimental results show that the proposed method can precisely regulate the output torque of the gyro,rapidly and effectively mitigating the risk of imminent rollover.This method provides a promising solution for wheeled robot stability and a theoretical basis for advanced safety control in agricultural robotics.展开更多
To emulate the functionality of the human retina and achieve a neuromorphic visual system,the development of a photonic synapse capable of multispectral color discrimination is of paramount importance.However,attainin...To emulate the functionality of the human retina and achieve a neuromorphic visual system,the development of a photonic synapse capable of multispectral color discrimination is of paramount importance.However,attaining robust color discrimination across a wide intensity range,even irrespective of medium limitations in the channel layer,poses a significant challenge.Here,we propose an approach that can bestow the color-discriminating synaptic functionality upon a three-terminal transistor flash memory even with enhanced discriminating capabilities.By incorporating the strong induced dipole moment effect at the excitation,modulated by the wavelength of the incident light,into the floating gate,we achieve outstanding RGB color-discriminating synaptic functionality within a remarkable intensity range spanning from 0.05 to 40 mW cm^(-2).This approach is not restricted to a specific medium in the channel layer,thereby enhancing its applicability.The effectiveness of this color-discriminating synaptic functionality is demonstrated through visual pre-processing of a photonic synapse array,involving the differentiation of RGB channels and the enhancement of image contrast with noise reduction.Consequently,a convolutional neural network can achieve an impressive inference accuracy of over 94%for Canadian-Institute-For-Advanced-Research-10 colorful image recognition task after the pre-processing.Our proposed approach offers a promising solution for achieving robust and versatile RGB color discrimination in photonic synapses,enabling significant advancements in artificial visual systems.展开更多
Precise modulation of the active layer morphology to optimize exciton dissociation and charge collection efficiency is the research priority in organic solar cells(OSCs).In this work,two novel additives,TFFB as well a...Precise modulation of the active layer morphology to optimize exciton dissociation and charge collection efficiency is the research priority in organic solar cells(OSCs).In this work,two novel additives,TFFB as well as TCFB,are proposed and doped into acceptor using layer-by-layer deposition method to realize high-performance bilayer OSCs based on D18-Cl/Y6 system.The asymmetric additive TFFB was introduced to improve molecular polarity,facilitate molecular stacking and promote film crystallization.Compared to the control devices without additive-treated,power conversion efficiency(PCE)of D18-Cl/Y6(TFFB)OSCs was increased from 18.04%to 18.85%.Furthermore,TCFB with trichloromethyl instead of trifluoromethyl caused large quadrupole moment,which further enhanced the intermolecular interactions and induced the components distribution to form a better three-dimensional morphology structure.Corresponding D18-Cl/Y6(TCFB)devices achieved an excellent PCE of 19.15%,one of the highest PCE reported for binary OSCs to date.In addition,TCFB-treated devices exhibited favorable storage stability,remaining over 95%of the original efficiency after 2500 hours of placement.This study presents a simple and valid method that utilizing the role of quadrupole moment to optimize the hierarchical morphology and improve the charge dynamics process,finally realizing highly efficient and stable OSCs.展开更多
Self-assembled monolayers(SAMs)have been commonly employed as hole-selective layers(HSLs)in inverted(p-i-n)perovskite solar cells(PSCs),and typically only a single-component SAM is applied,which plays limited role in ...Self-assembled monolayers(SAMs)have been commonly employed as hole-selective layers(HSLs)in inverted(p-i-n)perovskite solar cells(PSCs),and typically only a single-component SAM is applied,which plays limited role in selective hole transport.Herein,we synthesize a novel SAM,(4-(3,11-dibro mo-7H-dibenzo[c,g]carbazol-7-yl)butyl)phosphonic acid(Br-4PADBC),and apply it as a complementary component to the commonly used[2-(3,6-dimeth oxy-9H-carbazol-9-yl)ethyl]phosphonic acid(MeO-2PACz)SAM,accomplishing boosted hole transport in inverted PSCs.A series of characterizations and theoretical calculations are employed to unravel the roles of each components within the binary SAM(bi-SAM).The involvements of the non-planar dibenzo[c,g]carbazole unit and electron-withdrawing Br atoms induce larger dipole moment of Br-4PADBC than MeO-2PACz,resulting in much deeper work function of ITO and consequently improved alignment with the valence band energy level of perovskite.Besides,the introduced Br atoms improve the quality of perovskite crystals and help passivate defects of perovskite.On the other hand,the existence of the conventional MeO-2PACz SAM ensures the considerable conductivity of the bi-SAM and thus efficient hole extraction from the perovskite layer.As a result,inverted PSC devices based on bi-SAM HSL deliver a decent power conversion efficiency(PCE)of 24.52%as well as dramatically improved thermal and operational stabilities.展开更多
基金supported by the“CUG Scholar”Scientific Research Funds at China University of Geosciences(Wuhan)(No.2021230)supported by the National Natural Science Foundation of China(Nos.41922025,42204062)。
文摘INTRODUCTION.On January 7,2025,at 9:05 AM BJT,a MS6.8 earthquake(CENC epicenter:28.50°N,87.45°E)struck Dingri County,Xizang Province(hereinafter referred to as the Dingri mainshock).The inferred moment magnitude,based on regional/teleseismic waveform inversion and back-projection,is approximately MW7.1.Focal mechanism solutions,aftershock distribution,and field surveys indicate that the Dingri mainshock was a normal-faulting event,with a nearly north-south strike and a westward-dipping fault plane.
基金supported by National Natural Science Foundation of China(Project No.51878156,received by Wen-Wei Wang) and EPC Innovation Consulting Project for Longkou Nanshan LNG Phase I Receiving Terminal(Z2000LGENT0399,received by Wen-Wei Wang and ZhaoJun Zhang).
文摘This study aimed to investigate the moment redistribution in continuous glass fiber reinforced polymer(GFRP)-concrete composite slabs caused by concrete cracking and steel bar yielding in the negative bending moment zone.An experimental bending moment redistribution test was conducted on continuous GFRP-concrete composite slabs,and a calculation method based on the conjugate beam method was proposed.The composite slabs were formed by combining GFRP profiles with a concrete layer and supported on steel beams to create two-span continuous composite slab specimens.Two methods,epoxy resin bonding,and stud connection,were used to connect the composite slabs with the steel beams.The experimental findings showed that the specimen connected with epoxy resin exhibited two moments redistribution phenomena during the loading process:concrete cracking and steel bar yielding at the internal support.In contrast,the composite slab connected with steel beams by studs exhibited only one-moment redistribution phenomenon throughout the loading process.As the concrete at the internal support cracked,the bending moment decreased in the internal support section and increased in the midspan section.When the steel bars yielded,the bending moment further decreased in the internal support section and increased in the mid-span section.Since GFRP profiles do not experience cracking,there was no significant decrease in the bending moment of the mid-span section.All test specimens experienced compressive failure of concrete at the mid-span section.Calculation results showed good agreement between the calculated and experimental values of bending moments in the mid-span section and internal support section.The proposed model can effectively predict the moment redistribution behavior of continuous GFRP-concrete composite slabs.
文摘To further understand the performance of the energy harvesters under the influence of the wind force and the random excitation,this paper investigates the stochastic response of the bio-inspired energy harvesters subjected to Gaussian white noise and galloping excitation,simulating the flapping pattern of a seagull and its interaction with wind force.The equivalent linearization method is utilized to convert the original nonlinear model into the Itôstochastic differential equation by minimizing the mean squared error.Then,the second-order steady-state moments about the displacement,velocity,and voltage are derived by combining the moment analysis theory.The theoretical results are simulated numerically to analyze the stochastic response performance under different noise intensities,wind speeds,stiffness coefficients,and electromechanical coupling coefficients,time domain analysis is also conducted to study the performance of the harvester with different parameters.The results reveal that the mean square displacement and voltage increase with increasing the noise intensity and wind speed,larger absolute values of stiffness coefficient correspond to smaller mean square displacement and voltage,and larger electromechanical coupling coefficients can enhance the mean square voltage.Finally,the influence of wind speed and electromechanical coupling coefficient on the stationary probability density function(SPDF)is investigated,revealing the existence of a bimodal distribution under varying environmental conditions.
文摘In this paper,we introduce the real pairwise completely positive(RPCP)matrices with one of them is necessarily positive semidefinite while the other one is necessarily entrywise nonnegative,which has a real pairwise completely positive(RPCP)decomposition.We study the properties of RPCP matrices and give some necessary and sufficient conditions for a matrix pair to be RPCP.First,we give an equivalent decomposition for the RPCP matrices,which is different from the RPCP-decomposition and show that the matrix pair(X,X)is RPCP if and only if X is completely positive.Besides,we also prove that the RPCP matrices checking problem is equivalent to the separable completion problem.A semidefinite algorithm is also proposed for detecting whether or not a matrix pair is RPCP.The asymptotic and finite convergence of the algorithm are also discussed.If it is RPCP,we can further give a RPCP-decomposition for it;if it is not,we can obtain a certificate for this.
文摘Beyond business,the CIIE is a vibrant platform where diverse cultures meet,share,and shine The eighth China International Import Expo,held from 5 to 10 November in Shanghai,once again served as a premier stage for exhibitors from around the world to showcase their distinctive cultures.From food and clothing to a wide array of arts,the more than 900,000 visitors were treated to a rich tapestry of cultural experiences from across the globe.
文摘Powered fight in birds is reliant on feathers forming an aerodynamic surface that resists air pressures.Many basic aspects of feather functionality are unknown,which hampers our understanding of wing function in birds.This study measured the dimensions of primary and secondaryfight feathers of 19 species of parrots.The maximum force the feathers could withstand from below was also measured to mimic the pressuresexperienced during a downstroke.The analysis tested whether:(1)feather dimensions differed along the wing and among secondary and primary remiges;(2)the force that feathers could withstand varied among the remiges;and(3)there would be isometric relationships with bodymass for feather characteristics.The results show that body mass signifcantly affected vane width,rachis thickness,maximum force,and ultimate bending moment,but the relationship for feather length only approached signifcance.Many of the proximal secondary feathers showedsignifcantly lower values relative to the frst primary,whereas for distal primaries the values were greater.There were isometric relationships forforce measurements of primary and secondary feathers with body mass,but there was positive allometry for feather lengths and vane widths.The forces feathers can withstand vary along the wing may be a proxy for the aerodynamic properties of the feathers in situ.Broader taxonomicstudies that explore these topics are required for other species representing a range of different orders.A better understanding of the functionality of feathers will improve our understanding of how avian fight works particularly considering the variety in fight style and wing shape in birds.
基金supported by the National Natural Science dation Foun-of China(Grant Number 42272204)Key Laboratory of Coal sources Re-Exploration and Comprehensive Utilization,Ministry of Natural Resources,Canada(SMDZ-KF2024-4)+1 种基金the Fundamental Research Funds for the Central Universities,China(Grant No.2024JCCXDC06)supported in part by open fund project of State Key Laboratory for Fine Exploration and Intelligent Development of Coal Research(SKLCRSM23KFA04)。
文摘This paper proposed a moment tensor regression prediction technology based on ResNet for microseismic events.Taking the great advantages of deep networks in classification and regression tasks,it can realize the great potential of fast and accurate inversion of microseismic moment tensors after the network trained.This ResNet-based moment tensor prediction technology,whose input is raw recordings,does not require the extraction of data features in advance.First,we tested the network using synthetic data and performed a quantitative assessment of the errors.The results demonstrate that the network exhibits high accuracy and efficiency during the prediction phase.Next,we tested the network using real microseismic data and compared the results with those from traditional inversion methods.The error in the results was relatively small compared to traditional methods.However,the network operates more efficiently without requiring manual intervention,making it highly valuable for near-real-time monitoring applications.
文摘This paper employs Granger causality analysis and the generalized impulse response function(GIRF)to study the higher-order moment spillover effects among Bitcoin,stock markets,and foreign exchange markets in the U.S.Using intraday high-frequency data,the research focuses on the interactions across higher-order moments,including volatility,jumps,skewness,and kurtosis.The results reveal significant bidirectional spillover effects between Bitcoin and traditional financial assets,particularly in terms of volatility and jump behavior,indicating that the cryptocurrency market has become a crucial component of global financial risk transmission.This study provides new theoretical perspectives and policy recommendations for global asset allocation,market regulation,and risk management,underscoring the importance of proactive management measures in addressing the complex risk interactions between cryptocurrencies and traditional financial markets.
基金Derek Elsworth acknowledges the support from a Gledden Visiting Fellowship from the Institute of Advanced Studies at the University of Western Australia,Australia,and the G.Albert Shoemaker Endowment at Pennsylvania State University,USA.
文摘Triggered seismicity is a key hazard where fluids are injected or withdrawn from the subsurface and may impact permeability. Understanding the mechanisms that control fluid injection-triggered seismicity allows its mitigation. Key controls on seismicity are defined in terms of fault and fracture strength, second-order frictional response and stability, and competing fluid-driven mechanisms for arrest. We desire to constrain maximum event magnitudes in triggered earthquakes by relating pre-existing critical stresses to fluid injection volume to explain why some recorded events are significantly larger than anticipated seismic moment thresholds. This formalism is consistent with several uncharacteristically large fluid injection-triggered earthquakes. Such methods of reactivating fractures and faults by hydraulic stimulation in shear or tensile fracturing are routinely used to create permeability in the subsurface. Microearthquakes (MEQs) generated by such stimulations can be used to diagnose permeability evolution. Although high-fidelity data sets are scarce, the EGS-Collab and Utah FORGE hydraulic stimulation field demonstration projects provide high-fidelity data sets that concurrently track permeability evolution and triggered seismicity. Machine learning deciphers the principal features of MEQs and the resulting permeability evolution that best track permeability changes – with transfer learning methods allowing robust predictions across multiple eological settings. Changes in permeability at reactivated fractures in both shear and extensional modes suggest that permeability change (Δk) scales with the seismic moment (M) of individual MEQs as Δk∝M. This scaling relation is exact at early times but degrades with successive MEQs, but provides a method for characterizing crustal permeability evolution using MEQs, alone. Importantly, we quantify for the first time the role of prestress in defining the elevated magnitude and seismic moment of fluid injection-triggered events, and demonstrate that such MEQs can also be used as diagnostic in quantifying permeability evolution in the crust.
文摘A new polarization–interference biomedical diagnostic three-dimensional(3D)Jones-matrix technology with digital Fourier reconstruction of layered maps of optical anisotropy(thesiograms)of dehydrated films(facies)of biological fluids of human organs is presented and experimentally tested.An original model of layered phase scanning of polycrystalline architectonics of supramolecular networks of biological fluid facies is proposed for the purpose of theoretical justification and prognostic use of the obtained results.On its basis,algorithms of Jones-matrix reconstruction of thesiograms of birefringence and dichroism of facies of synovial fluid,bile and blood are found.As a result,layered thesiograms of linear and circular birefringence and dichroism of facies with different spatial–angular architectonics of supramolecular networks are experimentally obtained for the first time.Within the framework of statistical analysis of experimental data,new objective markers(asymmetry and excess of optical anisotropy parameter distributions)for diagnostics of pathological changes in the optical anisotropy of biological fluid facies were defined and clinically tested.As a result,an excellent level of balanced accuracy of the developed polarization–interference Jones-matrix method of layer-by-layer reconstruction of thesiograms of polycrystalline supramolecular networks in differential diagnostics of bile facies(cholelithiasis),synovial fluid(reactive synovitis–septic arthritis)and whole blood(follicular adenoma–papillary thyroid cancer)was achieved.
基金funded by the Open Access Initiative of the University of Bremen and the DFG via SuUB BremenThe authors extend their appreciation to the Deanship of Research and Graduate Studies at King Khalid University for funding this work through Large Group Project under grant number(RGP2/367/46)+1 种基金This research is supported and funded by Princess Nourah bint Abdulrahman University Researchers Supporting Project number(PNURSP2025R410)Princess Nourah bint Abdulrahman University,Riyadh,Saudi Arabia.
文摘As urban landscapes evolve and vehicular volumes soar,traditional traffic monitoring systems struggle to scale,often failing under the complexities of dense,dynamic,and occluded environments.This paper introduces a novel,unified deep learning framework for vehicle detection,tracking,counting,and classification in aerial imagery designed explicitly for modern smart city infrastructure demands.Our approach begins with adaptive histogram equalization to optimize aerial image clarity,followed by a cutting-edge scene parsing technique using Mask2Former,enabling robust segmentation even in visually congested settings.Vehicle detection leverages the latest YOLOv11 architecture,delivering superior accuracy in aerial contexts by addressing occlusion,scale variance,and fine-grained object differentiation.We incorporate the highly efficient ByteTrack algorithm for tracking,enabling seamless identity preservation across frames.Vehicle counting is achieved through an unsupervised DBSCAN-based method,ensuring adaptability to varying traffic densities.We further introduce a hybrid feature extraction module combining Convolutional Neural Networks(CNNs)with Zernike Moments,capturing both deep semantic and geometric signatures of vehicles.The final classification is powered by NASNet,a neural architecture search-optimized model,ensuring high accuracy across diverse vehicle types and orientations.Extensive evaluations of the VAID benchmark dataset demonstrate the system’s outstanding performance,achieving 96%detection,94%tracking,and 96.4%classification accuracy.On the UAVDT dataset,the system attains 95%detection,93%tracking,and 95%classification accuracy,confirming its robustness across diverse aerial traffic scenarios.These results establish new benchmarks in aerial traffic analysis and validate the framework’s scalability,making it a powerful and adaptable solution for next-generation intelligent transportation systems and urban surveillance.
文摘In this paper,an image processing algorithm which is able to synthesize material textures of arbitrary shapes is proposed.The presented approach uses an arbitrary image to construct a structure layer of the material.The resulting structure layer is then used to constrain the material texture synthesis.The field of second-moment matrices is used to represent the structure layer.Many tests with various constraint images are conducted to ensure that the proposed approach accurately reproduces the visual aspects of the input material sample.The results demonstrate that the proposed algorithm is able to accurately synthesize arbitrary-shaped material textures while respecting the local characteristics of the exemplar.This paves the way toward the synthesis of 3D material textures of arbitrary shapes from 2D material samples,which has a wide application range in virtual material design and materials characterization.
基金the Graduate Innovation Program of China University of Mining and Technology,the Fundamental Research Funds for the Central Universities(Grant No.2023WLKXJ017)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX23_2776)the Shandong Energy Group(Grant No.SNKJ2022BJ03-R28)。
文摘In this study,we employed Bayesian inversion coupled with the summation-by-parts and simultaneousapproximation-term(SBP-SAT)forward simulation method to elucidate the mechanisms behind mininginduced seismic events caused by fault slip and their potential effects on rockbursts.Through Bayesian inversion,it is determined that the sources near fault FQ14 have a significant shear component.Additionally,we analyzed the stress and displacement fields of high-energy events,along with the hypocenter distribution of aftershocks,which aided in identifying the slip direction of the critically stressed fault FQ14.We also performed forward modeling to capture the complex dynamics of fault slip under varying friction laws and shear fracture modes.The selection of specific friction laws for fault slip models was based on their ability to accurately replicate observed slip behavior under various external loading conditions,thereby enhancing the applicability of our findings.Our results suggest that the slip behavior of fault FQ14 can be effectively understood by comparing different scenarios.
文摘In the current digital context,safeguarding copyright is a major issue,particularly for architectural drawings produced by students.These works are frequently the result of innovative academic thinking combining creativity and technical precision.They are particularly vulnerable to the risk of illegal reproduction when disseminated in digital format.This research suggests,for the first time,an innovative approach to copyright protection by embedding a double digital watermark to address this challenge.The solution relies on a synergistic fusion of several sophisticated methods:Krawtchouk Optimized Octonion Moments(OKOM),Quaternion Singular Value Decomposition(QSVD),and Discrete Waveform Transform(DWT).To improve watermark embedding,the biologically inspired algorithm Chaos-White Shark Optimization(CWSO)is used,which allows dynamically adapting essential parameters such as the scaling factor of the insertion.Thus,two watermarks are inserted at the same time:an institutional logo and a student image,encoded in the main image(the architectural plan)through octonionic projections.This allows minimizing the amount of data to be integrated while increasing resistance.The suggested approach guarantees a perfect balance between the discreetness of the watermark(validated by PSNR indices>47 dB and SSIM>0.99)and its resistance to different attacks(JPEG compression,noise,rotation,resizing,filtering,etc.),as proven by the normalized correlation values(NC>0.9)obtained following the extraction.Therefore,this method represents a notable progress for securing academic works in architecture,providing an effective,discreet and reversible digital protection,which does not harm the visual appearance of the original works.
基金Supported by Anhui Engineering Research Center on Information Fusion and Control of Intelligent Robot(Grant No.IFCIR2024014)Open Fund Key Laboratory of Machine Vision Inspection of Anhui Provincial,China(Grant No.KLMVI-2024-HIT-14)+2 种基金University Synergy Innovation Program of Anhui Province,China(Grant No.GXXT-2023-076)Anhui Future Technology Research Institute Enterprise Cooperation Project(Grant No.2023qyhz35)2024 Wuhu Science and Technology Planning Project(Grant Nos.2024cj40,2024cxy24).
文摘To effectively improve the adaptability and traversal abilities of a multi-terrain mobile robot under the dynamic excitation of multiple roads,we explore the mobile robot’s vibration and joint driving output stall caused by the dynamic excitation of the road spectrum function and analyze techniques for reducing the vibration and enhancing the driving moment of a four-wheel differential-speed mobile robot.A double-wishbone vibration reduction suspension and a moment compensator were designed for a multi-terrain mobile robot by theoretically describing its suspensionwheel-road dynamics.Also,the mobile robot’s road adaptability and traversal abilities were mathematically characterized under dynamic excitation.Co-simulation in ADAMS-MATLAB/Simulink is performed such as the harsh condition of in situ rotation and outdoor experimental schemes are implemented in which the experimental data are analyzed.The experimental result verifies the correctness of the theoretical analysis,as well as the effectiveness of the vibration reduction suspension and the moment compensator.The compatibility of the mobile robot’s driving mechanisms with road traversal abilities has been improved under various terrain conditions in complex field operation scenarios.
文摘With the rapid development of Internet of things technology,the efficiency of data transmission between devices has been significantly improved.However,the open network environment also poses serious security risks.This paper proposes an innovative fingerprint template protection scheme,which generates key streams through an improved fourdimensional superchaotic system(4CSCS),uses the space-filling property of Hilbert curves to achieve pixel scrambling,and introduces dynamic DNA encoding to improve encryption.Experimental results show that this scheme has a large key space 2^(528),encrypts image information entropy of more than 7.9970,and shows excellent performance in defending against statistical attacks and differential attacks.Compared with existing methods,this scheme has significant advantages in terms of encryption performance and security,and provides a reliable protection mechanism for fingerprint authentication systems in the Internet of things environment.
基金supported by the National Natural Science Foundation of China(No.52175259)the 2115 Talent Development Program of China Agricultural University.
文摘Rollover accidents involving agricultural wheeled robots,accompanied by severe mechanical impacts,pose serious threats to operational safety and reduce functional efficiency.To address this issue,an active rollover prevention strategy is proposed,utilizing a single‐gimbal control moment gyro(SGCMG),to stabilize typical agricultural robots and prevent potential rollovers.To match the free oscillation of the pivot front axle,a novel recovery torque model of the coupled robot‐SGCMG system is established,in which two patterns are introduced to refine the rollover process with uncertain parameters.Additionally,a lateral stability index is adopted and analyzed to assess the hazard level of potential rollovers.Aimed at handling uncertain parameters and hazard levels,an adaptive backstepping control strategy is developed for real‐time anti‐rollover implementation.Within this strategy,control gains are adaptively tuned based on theoretical derivations,thereby suppressing rollover tendency while minimizing tuning effort.For verification,a scaled experimental platform,designed according to similarity theory,is constructed to ensure safety of personnel and equipment.Experimental results show that the proposed method can precisely regulate the output torque of the gyro,rapidly and effectively mitigating the risk of imminent rollover.This method provides a promising solution for wheeled robot stability and a theoretical basis for advanced safety control in agricultural robotics.
基金supported by National Research Foundation of Korea(NRF)[RS-2024-00350701 and RS-2023-00207828].
文摘To emulate the functionality of the human retina and achieve a neuromorphic visual system,the development of a photonic synapse capable of multispectral color discrimination is of paramount importance.However,attaining robust color discrimination across a wide intensity range,even irrespective of medium limitations in the channel layer,poses a significant challenge.Here,we propose an approach that can bestow the color-discriminating synaptic functionality upon a three-terminal transistor flash memory even with enhanced discriminating capabilities.By incorporating the strong induced dipole moment effect at the excitation,modulated by the wavelength of the incident light,into the floating gate,we achieve outstanding RGB color-discriminating synaptic functionality within a remarkable intensity range spanning from 0.05 to 40 mW cm^(-2).This approach is not restricted to a specific medium in the channel layer,thereby enhancing its applicability.The effectiveness of this color-discriminating synaptic functionality is demonstrated through visual pre-processing of a photonic synapse array,involving the differentiation of RGB channels and the enhancement of image contrast with noise reduction.Consequently,a convolutional neural network can achieve an impressive inference accuracy of over 94%for Canadian-Institute-For-Advanced-Research-10 colorful image recognition task after the pre-processing.Our proposed approach offers a promising solution for achieving robust and versatile RGB color discrimination in photonic synapses,enabling significant advancements in artificial visual systems.
基金supported by the National Natural Science Foundation of China(NSFC Grant Nos.52130304,62222503 and 52073040)Sichuan Science and Technology Project(2023NSFSC1973,2024NSFSC0012,2024NSFSC1447,2025ZNSFSC1460 and 2025ZNSFSC0037)National Key R&D Program of China(2023YFB2604101).
文摘Precise modulation of the active layer morphology to optimize exciton dissociation and charge collection efficiency is the research priority in organic solar cells(OSCs).In this work,two novel additives,TFFB as well as TCFB,are proposed and doped into acceptor using layer-by-layer deposition method to realize high-performance bilayer OSCs based on D18-Cl/Y6 system.The asymmetric additive TFFB was introduced to improve molecular polarity,facilitate molecular stacking and promote film crystallization.Compared to the control devices without additive-treated,power conversion efficiency(PCE)of D18-Cl/Y6(TFFB)OSCs was increased from 18.04%to 18.85%.Furthermore,TCFB with trichloromethyl instead of trifluoromethyl caused large quadrupole moment,which further enhanced the intermolecular interactions and induced the components distribution to form a better three-dimensional morphology structure.Corresponding D18-Cl/Y6(TCFB)devices achieved an excellent PCE of 19.15%,one of the highest PCE reported for binary OSCs to date.In addition,TCFB-treated devices exhibited favorable storage stability,remaining over 95%of the original efficiency after 2500 hours of placement.This study presents a simple and valid method that utilizing the role of quadrupole moment to optimize the hierarchical morphology and improve the charge dynamics process,finally realizing highly efficient and stable OSCs.
基金the National Natural Science Foundation of China(51925206,U1932214,52302052)the National Natural Science Foundation of China(52322318)+6 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0450301)the Fundamental Research Funds for the Central Universities(WK2060000051,20720220009)the National Key Research and Development Program of China(No.2023YFB3809700)the Innovation and Technology Fund(GHP/100/20SZ,GHP/102/20GD,MRP/040/21X,ITS/147/22FP)the Research Grants Council of Hong Kong Grant(N_City U102/23,C4005-22Y,C1055-23G,11306521)the Green Tech Fund(GTF202020164)the Science Technology and Innovation Committee of Shenzhen Municipality(SGDX20210823104002015,JCYJ20220818101018038)。
文摘Self-assembled monolayers(SAMs)have been commonly employed as hole-selective layers(HSLs)in inverted(p-i-n)perovskite solar cells(PSCs),and typically only a single-component SAM is applied,which plays limited role in selective hole transport.Herein,we synthesize a novel SAM,(4-(3,11-dibro mo-7H-dibenzo[c,g]carbazol-7-yl)butyl)phosphonic acid(Br-4PADBC),and apply it as a complementary component to the commonly used[2-(3,6-dimeth oxy-9H-carbazol-9-yl)ethyl]phosphonic acid(MeO-2PACz)SAM,accomplishing boosted hole transport in inverted PSCs.A series of characterizations and theoretical calculations are employed to unravel the roles of each components within the binary SAM(bi-SAM).The involvements of the non-planar dibenzo[c,g]carbazole unit and electron-withdrawing Br atoms induce larger dipole moment of Br-4PADBC than MeO-2PACz,resulting in much deeper work function of ITO and consequently improved alignment with the valence band energy level of perovskite.Besides,the introduced Br atoms improve the quality of perovskite crystals and help passivate defects of perovskite.On the other hand,the existence of the conventional MeO-2PACz SAM ensures the considerable conductivity of the bi-SAM and thus efficient hole extraction from the perovskite layer.As a result,inverted PSC devices based on bi-SAM HSL deliver a decent power conversion efficiency(PCE)of 24.52%as well as dramatically improved thermal and operational stabilities.
