The ubiquitous adoption of mobile devices as essential platforms for sensitive data transmission has heightened the demand for secure client-server communication.Although various authentication and key agreement proto...The ubiquitous adoption of mobile devices as essential platforms for sensitive data transmission has heightened the demand for secure client-server communication.Although various authentication and key agreement protocols have been developed,current approaches are constrained by homogeneous cryptosystem frameworks,namely public key infrastructure(PKI),identity-based cryptography(IBC),or certificateless cryptography(CLC),each presenting limitations in client-server architectures.Specifically,PKI incurs certificate management overhead,IBC introduces key escrow risks,and CLC encounters cross-system interoperability challenges.To overcome these shortcomings,this study introduces a heterogeneous signcryption-based authentication and key agreement protocol that synergistically integrates IBC for client operations(eliminating PKI’s certificate dependency)with CLC for server implementation(mitigating IBC’s key escrow issue while preserving efficiency).Rigorous security analysis under the mBR(modified Bellare-Rogaway)model confirms the protocol’s resistance to adaptive chosen-ciphertext attacks.Quantitative comparisons demonstrate that the proposed protocol achieves 10.08%–71.34%lower communication overhead than existing schemes across multiple security levels(80-,112-,and 128-bit)compared to existing protocols.展开更多
With the expansion of peanut planting area year by year,film mulching cultivation has become increasingly important in peanut production due to its unique advantages in enhancing both yield per unit area and overall e...With the expansion of peanut planting area year by year,film mulching cultivation has become increasingly important in peanut production due to its unique advantages in enhancing both yield per unit area and overall economic benefits.Based on the varietal characteristics of‘Zhouhua 5’and addressing practical issues in peanut production,this paper summarized key techniques for high-yield and high-efficiency film mulching cultivation of this variety.These techniques cover all critical stages,including land preparation and fertilization,seed preparation,sowing methods,field management,and timely harvesting,providing technical guidance for varietal promotion and peanut production.展开更多
In electrochemical energy storage systems,the sodium-ion battery is typically integrated in the form of a“cell-module-cluster”,but its cross-scale thermal runaway triggering risk and the propagation mechanism remain...In electrochemical energy storage systems,the sodium-ion battery is typically integrated in the form of a“cell-module-cluster”,but its cross-scale thermal runaway triggering risk and the propagation mechanism remain unclear.This study reveals the cross-scale thermal runaway triggering and propagation behavior of sodium-ion batteries of“cell-module-cluster”under overcharge conditions,and investigates the effects of key factors,including module spacing,triggering cell location,and heat dissipation condition,on the thermal runaway propagation behavior.Results demonstrate that the thermal runaway propagation in a module containing the overcharged cell follows a sequential triggering mode,while thermal runaway in the downstream module exhibits a simultaneous triggering mode with greater severity.Furthermore,increasing the module spacing or enhancing the heat dissipation capacity can effectively reduce the heat accumulation and prevent the trigger of thermal runaway.On the above basis,the multi-dimensional evaluation strategy is proposed to quantitatively assess the hazard of sodium-ion battery cluster thermal runaway.The findings serve as a foundation for the safe design of sodium-ion batteries in energy storage systems.展开更多
Unmanned Aerial Vehicles(UAVs)in Flying Ad-Hoc Networks(FANETs)are widely used in both civilian and military fields,but they face severe security,trust,and privacy vulnerabilities due to their high mobility,dynamic to...Unmanned Aerial Vehicles(UAVs)in Flying Ad-Hoc Networks(FANETs)are widely used in both civilian and military fields,but they face severe security,trust,and privacy vulnerabilities due to their high mobility,dynamic topology,and open wireless channels.Existing security protocols for Mobile Ad-Hoc Networks(MANETs)cannot be directly applied to FANETs,as FANETs require lightweight,high real-time performance,and strong anonymity.The current FANETs security protocol cannot simultaneously meet the requirements of strong anonymity,high security,and low overhead in high dynamic and resource-constrained scenarios.To address these challenges,this paper proposes an Anonymous Authentication and Key Exchange Protocol(AAKE-OWA)for UAVs in FANETs based on OneWay Accumulators(OWA).During the UAV registration phase,the Key Management Center(KMC)generates an identity ticket for each UAV using OWA and transmits it securely to the UAV’s on-board tamper-proof module.In the key exchange phase,UAVs generate temporary authentication tickets with random numbers and compute the same session key leveraging the quasi-commutativity of OWA.For mutual anonymous authentication,UAVs encrypt random numbers with the session key and verify identities by comparing computed values with authentication values.Formal analysis using the Scyther tool confirms that the protocol resists identity spoofing,man-in-the-middle,and replay attacks.Through Burrows Abadi Needham(BAN)logic proof,it achieves mutual anonymity,prevents simulation and physical capture attacks,and ensures secure connectivity of 1.Experimental comparisons with existing protocols prove that the AAKE-OWA protocol has lower computational overhead,communication overhead,and storage overhead,making it more suitable for resource-constrained FANET scenarios.Performance comparison experiments show that,compared with other schemes,this scheme only requires 8 one-way accumulator operations and 4 symmetric encryption/decryption operations,with a total computational overhead as low as 2.3504 ms,a communication overhead of merely 1216 bits,and a storage overhead of 768 bits.We have achieved a reduction in computational costs from 6.3%to 90.3%,communication costs from 5.0%to 69.1%,and overall storage costs from 33%to 68%compared to existing solutions.It can meet the performance requirements of lightweight,real-time,and anonymity for unmanned aerial vehicles(UAVs)networks.展开更多
With the increasing application of lithium-ion batteries under high-rate operation,safety concerns such as thermal runaway(TR)and thermal runaway propagation(TRP)have become critical.In this study,the TRP action of ba...With the increasing application of lithium-ion batteries under high-rate operation,safety concerns such as thermal runaway(TR)and thermal runaway propagation(TRP)have become critical.In this study,the TRP action of batteries undergoing high-rate cycling is systematically investigated.Microanalysis results reveal that the crystallinity and I_((003))/I_((104))of the cathode are decreased by 32.95%and 13.01%after 4 C cycling,while the layered structure of the anode is seriously damaged.As revealed,the TR interval time(At)of batteries cycled at 4 C is decreased by 83.23%compared with that for batteries cycled at 1 C.Meanwhile,the maximum mass loss(ML)rate of Battery 2#is increased by 32.35%.We have further investigated the influence of battery spacing on TRP action.The maximum TR temperature of Battery2#at 1.5 cm spacing is reduced by 26.21%compared with the value at 0 cm spacing.When increasing the spacing from 0 to 1.5 cm,the ML of batteries is reduced by 20.73%.ML increases and decreases with the elevation of the charging rate and battery spacing,respectively.Compared with a battery cycled at1 C,a battery cycled at 4 C shows reduced heat required to trigger TR.The corresponding decreases can reach 68.28%,70.10%,76.88%,and 26.15%when setting the spacing at 0,0.6,1.5,and 2.1 cm,respectively.This indicates that Battery 2#can enter TR with much lower heat after high-rate cycling.Overall,high-rate cycling and low spacing accelerate the TRP of the battery and aggravate the TR severity of the battery.This work can provide insights for the practical safety design of energy storage systems.展开更多
Arc faults within the transformers can generate sudden pressure surges,constituting significant hazards that may precipitate oil tank explosions and severely compromise power system stability.Conventional power−freque...Arc faults within the transformers can generate sudden pressure surges,constituting significant hazards that may precipitate oil tank explosions and severely compromise power system stability.Conventional power−frequency arc discharge experiments encounter limitations in isolating pressure wave characteristics due to persistent gas generation and arc reignition.To circumvent these challenges,an oil-immersed impulse voltage discharge platform was conceived and engineered to investigate pressure wave propagation dynamics.A pressure numerical simulation model and theoretical model of oil−solid interface reflection and refraction were subsequently established to elucidate the pressure propagation mechanism.The experimental and simulation results show that the pressure wave generated by pulsed arc discharge in oil propagates radially in the form of spherical waves.Due to the viscous loss and wave front expansion of transformer oil,the peak pressure decays exponentially with distance,with a decay coefficientβ=1.15.When pressure waves encounter metal obstacles inside transformer oil,there are two propagation paths:direct transmission through and multiple reflections through,and a mode transformation of pressure waves occurs at the oil−solid interface,mainly propagating through obstacles in the form of transverse waves.This work quantitatively delineates the energy pressure wave coupling,propagation dynamics,and attenuation mechanisms,providing critical insights for assessing and mitigating arc fault-induced transformer explosion risks.展开更多
Hydraulic fracturing serves as a critical technology for reservoir stimulation in deep coalbed methane(CBM)development,where the mechanical properties of gangue layers exert a significant control on fracture propagati...Hydraulic fracturing serves as a critical technology for reservoir stimulation in deep coalbed methane(CBM)development,where the mechanical properties of gangue layers exert a significant control on fracture propagation behavior.To address the unclear mechanisms governing fracture penetration across coal-gangue interfaces,this study employs the Continuum-Discontinuum Element Method(CDEM)to simulate and analyze the vertical propagation of hydraulic fractures initiating within coal seams,based on geomechanical parameters derived from the deep Benxi Formation coal seams in the southeastern Ordos Basin.The investigation systematically examines the influence of geological and operational parameters on cross-interfacial fracture growth.Results demonstrate that vertical stress difference,elastic modulus contrast between coal and gangue layers,interfacial stress differential,and interfacial cohesion at coal-gangue interfaces are critical factors governing hydraulic fracture penetration through these interfaces.High vertical stress differences(>3 MPa)inhibit interfacial dilation,promoting predominant crosslayer fracture propagation.Reduced interfacial stress contrasts and enhanced interfacial cohesion facilitate fracture penetration across interfaces.Furthermore,smaller elastic modulus contrasts between coal and gangue correlate with increased interfacial aperture.Finally,lower injection rates effectively suppress vertical fracture propagation in deep coal reservoirs.This study elucidates the characteristics and mechanisms governing cross-layer fracture propagation in coal–rock composites with interbedded partings,and delineates the dynamic evolution laws and dominant controlling factors involved.Thefindings provide critical theoretical insights for the optimization of fracture design and the efficient development of deep coalbed methane reservoirs.展开更多
The study aimed at predicting potential suitable areas with national key reserve Orchidaceae plants in Heilongjiang province and conducive to plant protection.The distribution point data of six Orchidaceae plants and ...The study aimed at predicting potential suitable areas with national key reserve Orchidaceae plants in Heilongjiang province and conducive to plant protection.The distribution point data of six Orchidaceae plants and 19 bioclimatic variables were selected,and the environmental factors required for modeling were screened out by pearson correlation analysis and variance inflation factor(VIF)analysis.The potential suitable areas of Orchidaceae plants were predictat present and under different climate scenarios in 2090s by using geographic information system(GIS)and Maximum Entropy Model(MaxEnt).And then evaluated the prediction accuracy of the MaxEnt model using the AUC value,the TSS value and the Kappa value.The results showed that:1)The area under curve(AUC)values,true skill statistics(TSS)values and KAPPA values predicted by MaxEnt model were separately above 0.9,0.85 and 0.75.2)Under the climate scenario at present,the total suitable area of Orchidaceae plants was about 9.61×10^(6)km^(2),which was mainly distributed in Heilongjiang province.Among them,the high-suitable area of Cypripedium shanxiense S.C.Chen was the largest,the non-suitable area of Cypripedium guttatum Sw was the largest.3)Under different climate scenarios in 2090s,the total suitable area was slightly increasing(9.62×10^(6)km^(2)).Among them,Cypripedium shanxiense S.C.Chen and Gastrodiae Rhizoma both showed the trend of expansion to the southwest,China,and the suitable areas expanded significantly.Comprehensive factor analysis showed that temperature and precipitation were the main bioclimatic variables of suitable areas distribution,and the low emission scenario(SSP 2-4.5)will be more conducive to the survival of Orchidaceae plants.展开更多
To investigate the fracture initiation and propagation behavior of fractures in tight sandstone under the supercritical CO_(2)(SCCO_(2))shock fracturing,laboratory fracturing experiments were conducted using a true-tr...To investigate the fracture initiation and propagation behavior of fractures in tight sandstone under the supercritical CO_(2)(SCCO_(2))shock fracturing,laboratory fracturing experiments were conducted using a true-triaxial-like SCCO_(2)shock fracturing system.Computed tomography(CT)scanning and three-dimensional fracture reconstruction were employed to elucidate the effects of shock pressure,pore pressure,and in-situ stress on fracture characteristics.In addition,nuclear magnetic resonance(NMR)transverse relaxation time spectra were used to assess the internal damage induced by SCCO_(2)shock fracturing.The results indicate that,compared with conventional hydraulic fracturing and SCCO_(2)quasi-static fracturing,SCCO_(2)shock fracturing facilitates multidirectional fracture initiation and the formation of complex fracture networks.Increasing shock pressure more readily activates bedding-plane weaknesses,with main and subsidiary fractures interweaving into a dense fracture network.Under the same impulse intensity,elevated pore pressure reduces the effective normal stress and alters stress-wave scattering paths,thereby inducing more branch fractures and enhancing fracture complexity.An increase in differential in-situ stress promotes fracture propagation along the direction of the maximum principal stress,reduces branching,and simplifies fracture morphology.With increasing SCCO_(2)shock pressure,pore volume and connectivity generally increase:small-to-medium pores primarily respond through increased number and enhanced connectivity;when the shock pressure rises to 40-45 MPa,crack coalescence generates larger pores and fissures,which play a dominant role in improving flow pathways and effective storage space,ultimately forming a multiscale pore-fracture network.展开更多
The influence of different solution and aging conditions on the microstructure,impact toughness,and crack initiation and propagation mechanisms of the novel α+β titanium alloy Ti6422 was systematically investigated....The influence of different solution and aging conditions on the microstructure,impact toughness,and crack initiation and propagation mechanisms of the novel α+β titanium alloy Ti6422 was systematically investigated.By adjusting the furnace cooling time after solution treatment and the aging temperature,Ti6422 alloy samples were developed with a multi-level lamellar microstructure,in-cluding microscaleαcolonies and α_(p) lamellae,as well as nanoscale α_(s) phases.Extending the furnace cooling time after solution treatment at 920℃ for 1 h from 240 to 540 min,followed by aging at 600℃ for 6 h,increased the α_(p) lamella content,reduced the α_(s) phase content,expanded theαcolonies and α_(p) lamellae size,and improved the impact toughness from 22.7 to 53.8 J/cm^(2).Additionally,under the same solution treatment,raising the aging temperature from 500 to 700℃ resulted in a decrease in the α_(s) phase content and a growth in the thickness of the α_(p) lamella and α_(s) phase.The impact toughness increased significantly with these changes.Samples with high α_(p) lamellae content or large α_(s) phase size exhibited high crack initiation and propagation energies.Impact deformation caused severe kinking of the α_(p) lamellae in crack initiation and propagation areas,leading to a uniform and high-density kernel average misorientation(KAM)distribu-tion,enhancing plastic deformation coordination and uniformity.Moreover,the multidirectional arrangement of coarserαcolonies and α_(p) lamellae continuously deflect the crack propagation direction,inhibiting crack propagation.展开更多
The stability of rock slopes is frequently controlled by the initiation and propagation of inherent dominant cracks.This study systematically investigated these processes in valley slopes by combining fracture-mechani...The stability of rock slopes is frequently controlled by the initiation and propagation of inherent dominant cracks.This study systematically investigated these processes in valley slopes by combining fracture-mechanics analysis with transparent soil model tests.An analytical expression for the stress field at the dominant crack tip was derived from the slope stress distribution by superposing the corresponding stress intensity factors(SIFs).The theoretical predictions were then validated against observations from transparent soil model tests.The influences of slope angle(β),crack inclination angle(α),crack position parameter(b),and crack length parameter(h)on crack initiation and propagation were quantified.The results indicated that:(1)cracks at the slope crest tended to propagate in shear mode,and the shear crack initiation angle(θ_(s))was approximately 8°.Cracks at the slope toe might propagate in either tensile or shear mode.(2)θ_(s) at the slope crest increased withβ,b,and l,and decreased withα.The maximum change inθ_(s) induced by the considered parameters was approximately 30°.(3)The tensile crack initiation angle(θ_(t))at the slop toe decreased withβ,α,and l,while the influence of b was comparatively minor.The maximum change inθ_(t) caused by individual parameters ranged approximately from 25°to 60°.Predicted crack propagation modes and directions showed good agreement with experimental results.These findings provide theoretical guidance for stability assessments of valley slopes controlled by dominant crack propagation.展开更多
This paper presents a novel artificial intelligence(AI)-assisted two-stage method for optimising rock slope stability by integrating advanced 3D modelling with rock support design,aiming at minimising risks,material u...This paper presents a novel artificial intelligence(AI)-assisted two-stage method for optimising rock slope stability by integrating advanced 3D modelling with rock support design,aiming at minimising risks,material usage,and costs.In the first stage,an extended key block analysis identifies key blocks and key block groups,accounting for progressive failure and force interactions.The second stage uses AI algorithms to optimise rockbolting design,balancing stability,cost,and material use.The most efficient algorithms include the multi-objective tree-structured Parzen estimator(MOTPE)and non-dominated sorting genetic algorithms(NSGA-II and NSGA-III).Applied to the Larvik rock slope,the optimised solution uses 18 pre-tensioned cablebolts,providing 13.2 MN of active force and achieving a factor of safety of 1.31 while reducing the average anchorage length by approximately 16%compared to traditional design.The AI-assisted approach also reduces computation time by over 90%compared to Quasi-Monte Carlo(QMC)methods,demonstrating its efficiency for small-scale civil engineering projects and large-scale mining operations.The developed tool is practical,compatible with Building Information Modelling(BIM),and ready for engineering implementation,supporting sustainable and cost-effective rock slope stabilisation.While the method is largely automated,professional judgement remains crucial for verifying ground conditions and selecting the final solution.Future work will focus on integrating data uncertainties,addressing complex block deformation mechanisms,refining optimisation objectives,and improving the performance of multi-objective optimisation for slope rockboling applications to further enhance the method's versatility.展开更多
Scientific instruments serve as foundational pillars for both scientific progress and industrial innovation,enabling deep exploration and driving technological breakthroughs.Their independent controllability and conti...Scientific instruments serve as foundational pillars for both scientific progress and industrial innovation,enabling deep exploration and driving technological breakthroughs.Their independent controllability and continuous innovation are indispensable for sustaining a competitive advantage in technological development,thereby securing national scientific capacity and long-term strategic growth.At present,however,China faces substantial risks of technological"stranglehold"in the high-end scientific instrument domain.The underlying causes are multifaceted,arising not only from insufficient accumulation of core technologies but also from entrenched systemic and ecosystem-level barriers that impede the application,scaling,and promotion of domestic instruments.This paper provides a systematic analysis of the challenges hindering the widespread adoption of domestically developed scientific instruments and proposes practical pathways to build a new,integrated"R&D-application-promotion"ecosystem.This ecosystem is anchored in trust,driven by user demand,and shaped through collaborative innovation.Key initiatives include organizing user visits to instrument manufacturers,convening seminars on domestic alternatives to imported equipment,establishing demonstration centers for application and promotion,and involving end-users directly in the R&D and iterative upgrading of domestic instruments.Together,these efforts aim to close the final critical gap,advancing domestic instruments from merely"functional"to genuinely"user-friendly",and ultimately to"widely implemented".By doing so,this framework offers both theoretical grounding and practical guidance for achieving high-level scientific and technological self-reliance and sustained innovation capacity.展开更多
Military image encryption plays a vital role in ensuring the secure transmission of sensitive visual information from unauthorized access.This paper proposes a new Tri-independent keying method for encrypting military...Military image encryption plays a vital role in ensuring the secure transmission of sensitive visual information from unauthorized access.This paper proposes a new Tri-independent keying method for encrypting military images.The proposed encryption method is based on multilevel security stages of pixel-level scrambling,bitlevel manipulation,and block-level shuffling operations.For having a vast key space,the input password is hashed by the Secure Hash Algorithm 256-bit(SHA-256)for generating independently deterministic keys used in the multilevel stages.A piecewise pixel-level scrambling function is introduced to perform a dual flipping process controlled with an adaptive key for obscuring the spatial relationships between the adjacent pixels.Adynamicmasking scheme is presented for conducting a bit-level manipulation based on distinct keys that change over image regions,providing completely different encryption results on identical regions.To handle the global correlation between large-scale patterns,a chaotic index-map system is employed for shuffling image regions randomly across the image domain based on a logistic map seeded with a private key.Experimental results on a dataset of military images show the effectiveness of the proposed encryption method in producing excellent quantitative and qualitative results.The proposed method obtains uniform histogram distributions,high entropy values around the ideal(≈8 bits),Number of Pixel Change Rate(NPCR)values above 99.5%,and low Peak Signal-to-Noise Ratio(PSNR)over all encrypted images.This validates the robustness of the proposed method against cryptanalytic attacks,verifying its ability to serve as a practical basis for secure image transmission in defense systems.展开更多
Glucagon-like peptide-1 receptor agonists,originally developed for the treatment of type 2 diabetes mellitus,have been suggested as a potential disease-modifying treatment for Parkinson’s disease.Some clinical trials...Glucagon-like peptide-1 receptor agonists,originally developed for the treatment of type 2 diabetes mellitus,have been suggested as a potential disease-modifying treatment for Parkinson’s disease.Some clinical trials of glucagon-like peptide-1 receptor agonists have demonstrated that they can alleviate motor dysfunction and improve quality of life for patients with Parkinson’s disease.However,the mechanisms underlying the neuroprotective effects of glucagon-like peptide-1 receptor agonists have yet to be elucidated.In this study,we usedα-synuclein preformed fibrils to generate in vitro and in vivo models of Parkinson’s disease and investigated the effects of a short-acting glucagon-like peptide-1 receptor agonist,lixisenatide,on the propagation ofα-synuclein pathology.We found that lixisenatide reducedα-synuclein phosphorylation,aggregation,and propagation in cells treated withα-synuclein preformed fibrils,and that these effects were accompanied by decreased mitochondrial dysfunction and apoptosis.Additionally,lixisenatide treatment alleviated motor dysfunction and dopaminergic cell neurodegeneration 20 weeks after stereotactic injection ofα-synuclein preformed fibrils into the striatum of wild-type mice.In addition,lixisenatide inhibitedα-synuclein phosphorylation and seeding between neurons,mediated by neuronal lymphocyte-activation gene 3 expression.This study provides new insights into the mechanism underlying the disease-modifying effects of glucagon-like peptide-1 receptor agonists in the treatment of Parkinson’s disease.展开更多
Foreign body classification on coal conveyor belts is a critical component of intelligent coal mining systems.Previous approaches have primarily utilized convolutional neural networks(CNNs)to effectively integrate spa...Foreign body classification on coal conveyor belts is a critical component of intelligent coal mining systems.Previous approaches have primarily utilized convolutional neural networks(CNNs)to effectively integrate spatial and semantic information.However,the performance of CNN-based methods remains limited in classification accuracy,primarily due to insufficient exploration of local image characteristics.Unlike CNNs,Vision Transformer(ViT)captures discriminative features by modeling relationships between local image patches.However,such methods typically require a large number of training samples to perform effectively.In the context of foreign body classification on coal conveyor belts,the limited availability of training samples hinders the full exploitation of Vision Transformer’s(ViT)capabilities.To address this issue,we propose an efficient approach,termed Key Part-level Attention Vision Transformer(KPA-ViT),which incorporates key local information into the transformer architecture to enrich the training information.It comprises three main components:a key-point detection module,a key local mining module,and an attention module.To extract key local regions,a key-point detection strategy is first employed to identify the positions of key points.Subsequently,the key local mining module extracts the relevant local features based on these detected points.Finally,an attention module composed of self-attention and cross-attention blocks is introduced to integrate global and key part-level information,thereby enhancing the model’s ability to learn discriminative features.Compared to recent transformer-based frameworks—such as ViT,Swin-Transformer,and EfficientViT—the proposed KPA-ViT achieves performance improvements of 9.3%,6.6%,and 2.8%,respectively,on the CUMT-BelT dataset,demonstrating its effectiveness.展开更多
THE power industrial control system(power ICS)is thecore infrastructure that ensures the safe,stable,and efficient operation of power systems.Its architecture typi-cally adopts a hierarchical and partitioned end-edge-...THE power industrial control system(power ICS)is thecore infrastructure that ensures the safe,stable,and efficient operation of power systems.Its architecture typi-cally adopts a hierarchical and partitioned end-edge-cloud collaborative design.However,the large-scale integration ofdistributed renewable energy resources,coupled with the extensivedeployment of sensing and communication devices,has resulted inthe new-type power system characterized by dynamic complexityand high uncertainty[1]-[4].展开更多
Hydraulic stimulation technology is widely employed to enhance the permeability of geothermal reservoirs.Nevertheless,accurately predicting hydraulic fracture propagation in complex geological conditions remains chall...Hydraulic stimulation technology is widely employed to enhance the permeability of geothermal reservoirs.Nevertheless,accurately predicting hydraulic fracture propagation in complex geological conditions remains challenging,thereby hindering the effective utilization of existing natural fractures.In this study,a phase field model was developed utilizing the finite element method to examine the influence of fluid presence,stress conditions,and natural fractures on the initiation and propagation of hydraulic fractures.The model employs Biot's poroelasticity theory to establish the coupling between the displacement field and the fluid field,while the phase field theory is applied to simulate fracture behavior.The results show that whenσ_(x0)/σ_(y0)<3 or qf<20 kg/(m^(3)·s),the presence of natural fractures can alter the original propagation direction of hydraulic fractures.Conversely,in the absence of these conditions,the propagation path of natural fractures is predominantly influenced by the initial stress field.Furthermore,based on the analysis of breakdown pressure and damage area,the optimal intersection angle between natural fractures and hydraulic fractures is determined to range from 45°to 60°.Finally,once a dominant channel forms,initiating and propagating hydraulic fractures in other directions becomes increasingly difficult,even in highly fractured areas.This method tackles the challenges of initiating and propagating hydraulic fractures in complex geological conditions,providing a theoretical basis for optimizing Enhanced Geothermal System(EGS)projects.展开更多
Using the software ANSYS-19.2/Explicit Dynamics,this study performedfinite-element modeling of the large-diameter steel pipeline cross-section for the Beineu-Bozoy-Shymkent gas pipeline with a non-through straight crac...Using the software ANSYS-19.2/Explicit Dynamics,this study performedfinite-element modeling of the large-diameter steel pipeline cross-section for the Beineu-Bozoy-Shymkent gas pipeline with a non-through straight crack,strengthened by steel wire wrapping.The effects of the thread tensile force of the steel winding in the form of single rings at the crack edges and the wires with different winding diameters and pitches were also studied.The results showed that the strengthening was preferably executed at a minimum value of the thread tensile force,which was 6.4%more effective than that at its maximum value.The analysis of the influence of the winding dia-meters showed that the equivalent stresses increased by 32%from the beginning of the crack growth until the wire broke.The increment in winding diameter decelerated the disclosure of the edge crack and reduced its length by 8.2%.The analysis of the influence of the winding pitch showed that decreasing the distance between the winding turns also led to a 33.6%reduction in the length of the straight crack and a 7.9%reduction in the maximum stres-ses on the strengthened pipeline cross-section.The analysis of the temperature effect on the pipeline material,within a range from-40℃to+50℃,resulted in a crack length change of up to 5.8%.As the temperature dropped,the crack length decreased.Within such a temperature range,the maximum stresses were observed along the cen-tral area of the crack,which were equal to 413 MPa at+50℃and 440 MPa at-40℃.The results also showed that the presence of the steel winding in the pipeline significantly reduced the length of crack propagation up to 8.4 times,depending on the temperature effect and design parameters of prestressing.This work integrated the existing methods for crack localization along steel gas pipelines.展开更多
基金supported by the Key Project of Science and Technology Research by Chongqing Education Commission under Grant KJZD-K202400610the Chongqing Natural Science Foundation General Project Grant CSTB2025NSCQ-GPX1263.
文摘The ubiquitous adoption of mobile devices as essential platforms for sensitive data transmission has heightened the demand for secure client-server communication.Although various authentication and key agreement protocols have been developed,current approaches are constrained by homogeneous cryptosystem frameworks,namely public key infrastructure(PKI),identity-based cryptography(IBC),or certificateless cryptography(CLC),each presenting limitations in client-server architectures.Specifically,PKI incurs certificate management overhead,IBC introduces key escrow risks,and CLC encounters cross-system interoperability challenges.To overcome these shortcomings,this study introduces a heterogeneous signcryption-based authentication and key agreement protocol that synergistically integrates IBC for client operations(eliminating PKI’s certificate dependency)with CLC for server implementation(mitigating IBC’s key escrow issue while preserving efficiency).Rigorous security analysis under the mBR(modified Bellare-Rogaway)model confirms the protocol’s resistance to adaptive chosen-ciphertext attacks.Quantitative comparisons demonstrate that the proposed protocol achieves 10.08%–71.34%lower communication overhead than existing schemes across multiple security levels(80-,112-,and 128-bit)compared to existing protocols.
基金Supported by Zhoukou Key Science and Technology Research Project(20200816).
文摘With the expansion of peanut planting area year by year,film mulching cultivation has become increasingly important in peanut production due to its unique advantages in enhancing both yield per unit area and overall economic benefits.Based on the varietal characteristics of‘Zhouhua 5’and addressing practical issues in peanut production,this paper summarized key techniques for high-yield and high-efficiency film mulching cultivation of this variety.These techniques cover all critical stages,including land preparation and fertilization,seed preparation,sowing methods,field management,and timely harvesting,providing technical guidance for varietal promotion and peanut production.
基金supported by the Anhui Quality Infrastructure Standardization Project(Grant No.2024MKSO7)the Science and Technology Project of State Grid(SGAHDK00DJJS2310027)the Anhui Provincial Natural Science Foundation(Grant No.2208085UD03).
文摘In electrochemical energy storage systems,the sodium-ion battery is typically integrated in the form of a“cell-module-cluster”,but its cross-scale thermal runaway triggering risk and the propagation mechanism remain unclear.This study reveals the cross-scale thermal runaway triggering and propagation behavior of sodium-ion batteries of“cell-module-cluster”under overcharge conditions,and investigates the effects of key factors,including module spacing,triggering cell location,and heat dissipation condition,on the thermal runaway propagation behavior.Results demonstrate that the thermal runaway propagation in a module containing the overcharged cell follows a sequential triggering mode,while thermal runaway in the downstream module exhibits a simultaneous triggering mode with greater severity.Furthermore,increasing the module spacing or enhancing the heat dissipation capacity can effectively reduce the heat accumulation and prevent the trigger of thermal runaway.On the above basis,the multi-dimensional evaluation strategy is proposed to quantitatively assess the hazard of sodium-ion battery cluster thermal runaway.The findings serve as a foundation for the safe design of sodium-ion batteries in energy storage systems.
基金supported in part by National Natural Science Foundation of China(under Grant 61902163)the Jiangsu“Qing Lan Project”,Natural Science Foundation of the Jiangsu Higher Education Institutions of China(Major Research Project:23KJA520007)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.SJCX25_1303).
文摘Unmanned Aerial Vehicles(UAVs)in Flying Ad-Hoc Networks(FANETs)are widely used in both civilian and military fields,but they face severe security,trust,and privacy vulnerabilities due to their high mobility,dynamic topology,and open wireless channels.Existing security protocols for Mobile Ad-Hoc Networks(MANETs)cannot be directly applied to FANETs,as FANETs require lightweight,high real-time performance,and strong anonymity.The current FANETs security protocol cannot simultaneously meet the requirements of strong anonymity,high security,and low overhead in high dynamic and resource-constrained scenarios.To address these challenges,this paper proposes an Anonymous Authentication and Key Exchange Protocol(AAKE-OWA)for UAVs in FANETs based on OneWay Accumulators(OWA).During the UAV registration phase,the Key Management Center(KMC)generates an identity ticket for each UAV using OWA and transmits it securely to the UAV’s on-board tamper-proof module.In the key exchange phase,UAVs generate temporary authentication tickets with random numbers and compute the same session key leveraging the quasi-commutativity of OWA.For mutual anonymous authentication,UAVs encrypt random numbers with the session key and verify identities by comparing computed values with authentication values.Formal analysis using the Scyther tool confirms that the protocol resists identity spoofing,man-in-the-middle,and replay attacks.Through Burrows Abadi Needham(BAN)logic proof,it achieves mutual anonymity,prevents simulation and physical capture attacks,and ensures secure connectivity of 1.Experimental comparisons with existing protocols prove that the AAKE-OWA protocol has lower computational overhead,communication overhead,and storage overhead,making it more suitable for resource-constrained FANET scenarios.Performance comparison experiments show that,compared with other schemes,this scheme only requires 8 one-way accumulator operations and 4 symmetric encryption/decryption operations,with a total computational overhead as low as 2.3504 ms,a communication overhead of merely 1216 bits,and a storage overhead of 768 bits.We have achieved a reduction in computational costs from 6.3%to 90.3%,communication costs from 5.0%to 69.1%,and overall storage costs from 33%to 68%compared to existing solutions.It can meet the performance requirements of lightweight,real-time,and anonymity for unmanned aerial vehicles(UAVs)networks.
基金supported by the National Key Research and Development Plan(2023YFC30099000)the National Natural Science Foundation of China(52104197,52272396,52474233)+2 种基金the Major Basic Research Project of the Natural Science Foundation of the Jiangsu Higher Education Institutions(2020240521)the Open Fund of the State Key Laboratory of Fire Science(SKLFS)Program(HZ2025-KF03)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(SJCX25_0595)。
文摘With the increasing application of lithium-ion batteries under high-rate operation,safety concerns such as thermal runaway(TR)and thermal runaway propagation(TRP)have become critical.In this study,the TRP action of batteries undergoing high-rate cycling is systematically investigated.Microanalysis results reveal that the crystallinity and I_((003))/I_((104))of the cathode are decreased by 32.95%and 13.01%after 4 C cycling,while the layered structure of the anode is seriously damaged.As revealed,the TR interval time(At)of batteries cycled at 4 C is decreased by 83.23%compared with that for batteries cycled at 1 C.Meanwhile,the maximum mass loss(ML)rate of Battery 2#is increased by 32.35%.We have further investigated the influence of battery spacing on TRP action.The maximum TR temperature of Battery2#at 1.5 cm spacing is reduced by 26.21%compared with the value at 0 cm spacing.When increasing the spacing from 0 to 1.5 cm,the ML of batteries is reduced by 20.73%.ML increases and decreases with the elevation of the charging rate and battery spacing,respectively.Compared with a battery cycled at1 C,a battery cycled at 4 C shows reduced heat required to trigger TR.The corresponding decreases can reach 68.28%,70.10%,76.88%,and 26.15%when setting the spacing at 0,0.6,1.5,and 2.1 cm,respectively.This indicates that Battery 2#can enter TR with much lower heat after high-rate cycling.Overall,high-rate cycling and low spacing accelerate the TRP of the battery and aggravate the TR severity of the battery.This work can provide insights for the practical safety design of energy storage systems.
基金funded by the Science and Technology Program of State Grid Corporation of China(5500-202356358A-2-1-ZX).
文摘Arc faults within the transformers can generate sudden pressure surges,constituting significant hazards that may precipitate oil tank explosions and severely compromise power system stability.Conventional power−frequency arc discharge experiments encounter limitations in isolating pressure wave characteristics due to persistent gas generation and arc reignition.To circumvent these challenges,an oil-immersed impulse voltage discharge platform was conceived and engineered to investigate pressure wave propagation dynamics.A pressure numerical simulation model and theoretical model of oil−solid interface reflection and refraction were subsequently established to elucidate the pressure propagation mechanism.The experimental and simulation results show that the pressure wave generated by pulsed arc discharge in oil propagates radially in the form of spherical waves.Due to the viscous loss and wave front expansion of transformer oil,the peak pressure decays exponentially with distance,with a decay coefficientβ=1.15.When pressure waves encounter metal obstacles inside transformer oil,there are two propagation paths:direct transmission through and multiple reflections through,and a mode transformation of pressure waves occurs at the oil−solid interface,mainly propagating through obstacles in the form of transverse waves.This work quantitatively delineates the energy pressure wave coupling,propagation dynamics,and attenuation mechanisms,providing critical insights for assessing and mitigating arc fault-induced transformer explosion risks.
文摘Hydraulic fracturing serves as a critical technology for reservoir stimulation in deep coalbed methane(CBM)development,where the mechanical properties of gangue layers exert a significant control on fracture propagation behavior.To address the unclear mechanisms governing fracture penetration across coal-gangue interfaces,this study employs the Continuum-Discontinuum Element Method(CDEM)to simulate and analyze the vertical propagation of hydraulic fractures initiating within coal seams,based on geomechanical parameters derived from the deep Benxi Formation coal seams in the southeastern Ordos Basin.The investigation systematically examines the influence of geological and operational parameters on cross-interfacial fracture growth.Results demonstrate that vertical stress difference,elastic modulus contrast between coal and gangue layers,interfacial stress differential,and interfacial cohesion at coal-gangue interfaces are critical factors governing hydraulic fracture penetration through these interfaces.High vertical stress differences(>3 MPa)inhibit interfacial dilation,promoting predominant crosslayer fracture propagation.Reduced interfacial stress contrasts and enhanced interfacial cohesion facilitate fracture penetration across interfaces.Furthermore,smaller elastic modulus contrasts between coal and gangue correlate with increased interfacial aperture.Finally,lower injection rates effectively suppress vertical fracture propagation in deep coal reservoirs.This study elucidates the characteristics and mechanisms governing cross-layer fracture propagation in coal–rock composites with interbedded partings,and delineates the dynamic evolution laws and dominant controlling factors involved.Thefindings provide critical theoretical insights for the optimization of fracture design and the efficient development of deep coalbed methane reservoirs.
基金funded by Project of Scientific Research Business Expenses of Provincial Scientific Research Institutes in Heilongjiang Province(No.CZKYF2023-1-B024)Heilongjiang Academy of Sciences Dean Fund Project(No.YZ2022ZR02)+1 种基金the Science and Technology Basic Resources Investigation Program of China(No.2019FY100500)the Fundamental Research Funds for the Central Universities(No.2572023CT11).
文摘The study aimed at predicting potential suitable areas with national key reserve Orchidaceae plants in Heilongjiang province and conducive to plant protection.The distribution point data of six Orchidaceae plants and 19 bioclimatic variables were selected,and the environmental factors required for modeling were screened out by pearson correlation analysis and variance inflation factor(VIF)analysis.The potential suitable areas of Orchidaceae plants were predictat present and under different climate scenarios in 2090s by using geographic information system(GIS)and Maximum Entropy Model(MaxEnt).And then evaluated the prediction accuracy of the MaxEnt model using the AUC value,the TSS value and the Kappa value.The results showed that:1)The area under curve(AUC)values,true skill statistics(TSS)values and KAPPA values predicted by MaxEnt model were separately above 0.9,0.85 and 0.75.2)Under the climate scenario at present,the total suitable area of Orchidaceae plants was about 9.61×10^(6)km^(2),which was mainly distributed in Heilongjiang province.Among them,the high-suitable area of Cypripedium shanxiense S.C.Chen was the largest,the non-suitable area of Cypripedium guttatum Sw was the largest.3)Under different climate scenarios in 2090s,the total suitable area was slightly increasing(9.62×10^(6)km^(2)).Among them,Cypripedium shanxiense S.C.Chen and Gastrodiae Rhizoma both showed the trend of expansion to the southwest,China,and the suitable areas expanded significantly.Comprehensive factor analysis showed that temperature and precipitation were the main bioclimatic variables of suitable areas distribution,and the low emission scenario(SSP 2-4.5)will be more conducive to the survival of Orchidaceae plants.
基金Supported by the National Natural Science Foundation for Outstanding Young Scholars(52425402)National Natural Science Foundation of China(52341401)International(Regional)Cooperation and Exchange Program of the National Natural Science Foundation of China(W2412078)。
文摘To investigate the fracture initiation and propagation behavior of fractures in tight sandstone under the supercritical CO_(2)(SCCO_(2))shock fracturing,laboratory fracturing experiments were conducted using a true-triaxial-like SCCO_(2)shock fracturing system.Computed tomography(CT)scanning and three-dimensional fracture reconstruction were employed to elucidate the effects of shock pressure,pore pressure,and in-situ stress on fracture characteristics.In addition,nuclear magnetic resonance(NMR)transverse relaxation time spectra were used to assess the internal damage induced by SCCO_(2)shock fracturing.The results indicate that,compared with conventional hydraulic fracturing and SCCO_(2)quasi-static fracturing,SCCO_(2)shock fracturing facilitates multidirectional fracture initiation and the formation of complex fracture networks.Increasing shock pressure more readily activates bedding-plane weaknesses,with main and subsidiary fractures interweaving into a dense fracture network.Under the same impulse intensity,elevated pore pressure reduces the effective normal stress and alters stress-wave scattering paths,thereby inducing more branch fractures and enhancing fracture complexity.An increase in differential in-situ stress promotes fracture propagation along the direction of the maximum principal stress,reduces branching,and simplifies fracture morphology.With increasing SCCO_(2)shock pressure,pore volume and connectivity generally increase:small-to-medium pores primarily respond through increased number and enhanced connectivity;when the shock pressure rises to 40-45 MPa,crack coalescence generates larger pores and fissures,which play a dominant role in improving flow pathways and effective storage space,ultimately forming a multiscale pore-fracture network.
基金supported by the National Natural Science Foundation of China(No.52090041).
文摘The influence of different solution and aging conditions on the microstructure,impact toughness,and crack initiation and propagation mechanisms of the novel α+β titanium alloy Ti6422 was systematically investigated.By adjusting the furnace cooling time after solution treatment and the aging temperature,Ti6422 alloy samples were developed with a multi-level lamellar microstructure,in-cluding microscaleαcolonies and α_(p) lamellae,as well as nanoscale α_(s) phases.Extending the furnace cooling time after solution treatment at 920℃ for 1 h from 240 to 540 min,followed by aging at 600℃ for 6 h,increased the α_(p) lamella content,reduced the α_(s) phase content,expanded theαcolonies and α_(p) lamellae size,and improved the impact toughness from 22.7 to 53.8 J/cm^(2).Additionally,under the same solution treatment,raising the aging temperature from 500 to 700℃ resulted in a decrease in the α_(s) phase content and a growth in the thickness of the α_(p) lamella and α_(s) phase.The impact toughness increased significantly with these changes.Samples with high α_(p) lamellae content or large α_(s) phase size exhibited high crack initiation and propagation energies.Impact deformation caused severe kinking of the α_(p) lamellae in crack initiation and propagation areas,leading to a uniform and high-density kernel average misorientation(KAM)distribu-tion,enhancing plastic deformation coordination and uniformity.Moreover,the multidirectional arrangement of coarserαcolonies and α_(p) lamellae continuously deflect the crack propagation direction,inhibiting crack propagation.
基金financially supported by the National Nature Science Foundation of China(Nos.52379110 and 42207222)the Key Technologies for Accurate Diagnosis and Intelligent Prevention and Control of Slope Hazards in Open Pit Mines,181 Major R&D projects of Metallurgical Corporation of China Ltd。
文摘The stability of rock slopes is frequently controlled by the initiation and propagation of inherent dominant cracks.This study systematically investigated these processes in valley slopes by combining fracture-mechanics analysis with transparent soil model tests.An analytical expression for the stress field at the dominant crack tip was derived from the slope stress distribution by superposing the corresponding stress intensity factors(SIFs).The theoretical predictions were then validated against observations from transparent soil model tests.The influences of slope angle(β),crack inclination angle(α),crack position parameter(b),and crack length parameter(h)on crack initiation and propagation were quantified.The results indicated that:(1)cracks at the slope crest tended to propagate in shear mode,and the shear crack initiation angle(θ_(s))was approximately 8°.Cracks at the slope toe might propagate in either tensile or shear mode.(2)θ_(s) at the slope crest increased withβ,b,and l,and decreased withα.The maximum change inθ_(s) induced by the considered parameters was approximately 30°.(3)The tensile crack initiation angle(θ_(t))at the slop toe decreased withβ,α,and l,while the influence of b was comparatively minor.The maximum change inθ_(t) caused by individual parameters ranged approximately from 25°to 60°.Predicted crack propagation modes and directions showed good agreement with experimental results.These findings provide theoretical guidance for stability assessments of valley slopes controlled by dominant crack propagation.
基金support from Research Council of Norway via STIPINST PhD grant(Grant No.323307),Bever Control AS,and Bane NOR.
文摘This paper presents a novel artificial intelligence(AI)-assisted two-stage method for optimising rock slope stability by integrating advanced 3D modelling with rock support design,aiming at minimising risks,material usage,and costs.In the first stage,an extended key block analysis identifies key blocks and key block groups,accounting for progressive failure and force interactions.The second stage uses AI algorithms to optimise rockbolting design,balancing stability,cost,and material use.The most efficient algorithms include the multi-objective tree-structured Parzen estimator(MOTPE)and non-dominated sorting genetic algorithms(NSGA-II and NSGA-III).Applied to the Larvik rock slope,the optimised solution uses 18 pre-tensioned cablebolts,providing 13.2 MN of active force and achieving a factor of safety of 1.31 while reducing the average anchorage length by approximately 16%compared to traditional design.The AI-assisted approach also reduces computation time by over 90%compared to Quasi-Monte Carlo(QMC)methods,demonstrating its efficiency for small-scale civil engineering projects and large-scale mining operations.The developed tool is practical,compatible with Building Information Modelling(BIM),and ready for engineering implementation,supporting sustainable and cost-effective rock slope stabilisation.While the method is largely automated,professional judgement remains crucial for verifying ground conditions and selecting the final solution.Future work will focus on integrating data uncertainties,addressing complex block deformation mechanisms,refining optimisation objectives,and improving the performance of multi-objective optimisation for slope rockboling applications to further enhance the method's versatility.
基金Management Research Project on the Transformation of Scientific and Technological Achievements at Peking University Health Science Center(Grant No.KT202501)Peking University Health Science Center 2025 Party Building Research Project(General Category,No.2)。
文摘Scientific instruments serve as foundational pillars for both scientific progress and industrial innovation,enabling deep exploration and driving technological breakthroughs.Their independent controllability and continuous innovation are indispensable for sustaining a competitive advantage in technological development,thereby securing national scientific capacity and long-term strategic growth.At present,however,China faces substantial risks of technological"stranglehold"in the high-end scientific instrument domain.The underlying causes are multifaceted,arising not only from insufficient accumulation of core technologies but also from entrenched systemic and ecosystem-level barriers that impede the application,scaling,and promotion of domestic instruments.This paper provides a systematic analysis of the challenges hindering the widespread adoption of domestically developed scientific instruments and proposes practical pathways to build a new,integrated"R&D-application-promotion"ecosystem.This ecosystem is anchored in trust,driven by user demand,and shaped through collaborative innovation.Key initiatives include organizing user visits to instrument manufacturers,convening seminars on domestic alternatives to imported equipment,establishing demonstration centers for application and promotion,and involving end-users directly in the R&D and iterative upgrading of domestic instruments.Together,these efforts aim to close the final critical gap,advancing domestic instruments from merely"functional"to genuinely"user-friendly",and ultimately to"widely implemented".By doing so,this framework offers both theoretical grounding and practical guidance for achieving high-level scientific and technological self-reliance and sustained innovation capacity.
文摘Military image encryption plays a vital role in ensuring the secure transmission of sensitive visual information from unauthorized access.This paper proposes a new Tri-independent keying method for encrypting military images.The proposed encryption method is based on multilevel security stages of pixel-level scrambling,bitlevel manipulation,and block-level shuffling operations.For having a vast key space,the input password is hashed by the Secure Hash Algorithm 256-bit(SHA-256)for generating independently deterministic keys used in the multilevel stages.A piecewise pixel-level scrambling function is introduced to perform a dual flipping process controlled with an adaptive key for obscuring the spatial relationships between the adjacent pixels.Adynamicmasking scheme is presented for conducting a bit-level manipulation based on distinct keys that change over image regions,providing completely different encryption results on identical regions.To handle the global correlation between large-scale patterns,a chaotic index-map system is employed for shuffling image regions randomly across the image domain based on a logistic map seeded with a private key.Experimental results on a dataset of military images show the effectiveness of the proposed encryption method in producing excellent quantitative and qualitative results.The proposed method obtains uniform histogram distributions,high entropy values around the ideal(≈8 bits),Number of Pixel Change Rate(NPCR)values above 99.5%,and low Peak Signal-to-Noise Ratio(PSNR)over all encrypted images.This validates the robustness of the proposed method against cryptanalytic attacks,verifying its ability to serve as a practical basis for secure image transmission in defense systems.
基金supported by the National Natural Science Foundation of China,No.82271446(to JX).
文摘Glucagon-like peptide-1 receptor agonists,originally developed for the treatment of type 2 diabetes mellitus,have been suggested as a potential disease-modifying treatment for Parkinson’s disease.Some clinical trials of glucagon-like peptide-1 receptor agonists have demonstrated that they can alleviate motor dysfunction and improve quality of life for patients with Parkinson’s disease.However,the mechanisms underlying the neuroprotective effects of glucagon-like peptide-1 receptor agonists have yet to be elucidated.In this study,we usedα-synuclein preformed fibrils to generate in vitro and in vivo models of Parkinson’s disease and investigated the effects of a short-acting glucagon-like peptide-1 receptor agonist,lixisenatide,on the propagation ofα-synuclein pathology.We found that lixisenatide reducedα-synuclein phosphorylation,aggregation,and propagation in cells treated withα-synuclein preformed fibrils,and that these effects were accompanied by decreased mitochondrial dysfunction and apoptosis.Additionally,lixisenatide treatment alleviated motor dysfunction and dopaminergic cell neurodegeneration 20 weeks after stereotactic injection ofα-synuclein preformed fibrils into the striatum of wild-type mice.In addition,lixisenatide inhibitedα-synuclein phosphorylation and seeding between neurons,mediated by neuronal lymphocyte-activation gene 3 expression.This study provides new insights into the mechanism underlying the disease-modifying effects of glucagon-like peptide-1 receptor agonists in the treatment of Parkinson’s disease.
基金funded by the National Key Research and Development Program of China(grant number 2023YFC2907600)the National Natural Science Foundation of China(grant number 52504132)Tiandi Science and Technology Co.,Ltd.Science and Technology Innovation Venture Capital Special Project(grant number 2023-TD-ZD011-004).
文摘Foreign body classification on coal conveyor belts is a critical component of intelligent coal mining systems.Previous approaches have primarily utilized convolutional neural networks(CNNs)to effectively integrate spatial and semantic information.However,the performance of CNN-based methods remains limited in classification accuracy,primarily due to insufficient exploration of local image characteristics.Unlike CNNs,Vision Transformer(ViT)captures discriminative features by modeling relationships between local image patches.However,such methods typically require a large number of training samples to perform effectively.In the context of foreign body classification on coal conveyor belts,the limited availability of training samples hinders the full exploitation of Vision Transformer’s(ViT)capabilities.To address this issue,we propose an efficient approach,termed Key Part-level Attention Vision Transformer(KPA-ViT),which incorporates key local information into the transformer architecture to enrich the training information.It comprises three main components:a key-point detection module,a key local mining module,and an attention module.To extract key local regions,a key-point detection strategy is first employed to identify the positions of key points.Subsequently,the key local mining module extracts the relevant local features based on these detected points.Finally,an attention module composed of self-attention and cross-attention blocks is introduced to integrate global and key part-level information,thereby enhancing the model’s ability to learn discriminative features.Compared to recent transformer-based frameworks—such as ViT,Swin-Transformer,and EfficientViT—the proposed KPA-ViT achieves performance improvements of 9.3%,6.6%,and 2.8%,respectively,on the CUMT-BelT dataset,demonstrating its effectiveness.
基金partially supported by the National Natural Science Foundation of China(62293500,62293505,62233010,62503240)Natural Science Foundation of Jiangsu Province(BK20250679)。
文摘THE power industrial control system(power ICS)is thecore infrastructure that ensures the safe,stable,and efficient operation of power systems.Its architecture typi-cally adopts a hierarchical and partitioned end-edge-cloud collaborative design.However,the large-scale integration ofdistributed renewable energy resources,coupled with the extensivedeployment of sensing and communication devices,has resulted inthe new-type power system characterized by dynamic complexityand high uncertainty[1]-[4].
基金supported by the National Key Research and Development Program(2021YFB150740401)National Natural Science Foundation of China(42202336)the CAS Pioneer Hundred Talents Program in China(Y826031C01)。
文摘Hydraulic stimulation technology is widely employed to enhance the permeability of geothermal reservoirs.Nevertheless,accurately predicting hydraulic fracture propagation in complex geological conditions remains challenging,thereby hindering the effective utilization of existing natural fractures.In this study,a phase field model was developed utilizing the finite element method to examine the influence of fluid presence,stress conditions,and natural fractures on the initiation and propagation of hydraulic fractures.The model employs Biot's poroelasticity theory to establish the coupling between the displacement field and the fluid field,while the phase field theory is applied to simulate fracture behavior.The results show that whenσ_(x0)/σ_(y0)<3 or qf<20 kg/(m^(3)·s),the presence of natural fractures can alter the original propagation direction of hydraulic fractures.Conversely,in the absence of these conditions,the propagation path of natural fractures is predominantly influenced by the initial stress field.Furthermore,based on the analysis of breakdown pressure and damage area,the optimal intersection angle between natural fractures and hydraulic fractures is determined to range from 45°to 60°.Finally,once a dominant channel forms,initiating and propagating hydraulic fractures in other directions becomes increasingly difficult,even in highly fractured areas.This method tackles the challenges of initiating and propagating hydraulic fractures in complex geological conditions,providing a theoretical basis for optimizing Enhanced Geothermal System(EGS)projects.
基金funded by the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan(Grant No.AP19680589).
文摘Using the software ANSYS-19.2/Explicit Dynamics,this study performedfinite-element modeling of the large-diameter steel pipeline cross-section for the Beineu-Bozoy-Shymkent gas pipeline with a non-through straight crack,strengthened by steel wire wrapping.The effects of the thread tensile force of the steel winding in the form of single rings at the crack edges and the wires with different winding diameters and pitches were also studied.The results showed that the strengthening was preferably executed at a minimum value of the thread tensile force,which was 6.4%more effective than that at its maximum value.The analysis of the influence of the winding dia-meters showed that the equivalent stresses increased by 32%from the beginning of the crack growth until the wire broke.The increment in winding diameter decelerated the disclosure of the edge crack and reduced its length by 8.2%.The analysis of the influence of the winding pitch showed that decreasing the distance between the winding turns also led to a 33.6%reduction in the length of the straight crack and a 7.9%reduction in the maximum stres-ses on the strengthened pipeline cross-section.The analysis of the temperature effect on the pipeline material,within a range from-40℃to+50℃,resulted in a crack length change of up to 5.8%.As the temperature dropped,the crack length decreased.Within such a temperature range,the maximum stresses were observed along the cen-tral area of the crack,which were equal to 413 MPa at+50℃and 440 MPa at-40℃.The results also showed that the presence of the steel winding in the pipeline significantly reduced the length of crack propagation up to 8.4 times,depending on the temperature effect and design parameters of prestressing.This work integrated the existing methods for crack localization along steel gas pipelines.
