Behavior recognition of Hu sheep contributes to their intensive and intelligent farming.Due to the generally high density of Hu sheep farming,severe occlusion occurs among different behaviors and even among sheep perf...Behavior recognition of Hu sheep contributes to their intensive and intelligent farming.Due to the generally high density of Hu sheep farming,severe occlusion occurs among different behaviors and even among sheep performing the same behavior,leading to missing and false detection issues in existing behavior recognition methods.A high-low frequency aggregated attention and negative sample comprehensive score loss and comprehensive score soft non-maximum suppression-YOLO(HLNC-YOLO)was proposed for identifying the behavior of Hu sheep,addressing the issues of missed and erroneous detections caused by occlusion between Hu sheep in intensive farming.Firstly,images of four typical behaviors-standing,lying,eating,and drinking-were collected from the sheep farm to construct the Hu sheep behavior dataset(HSBD).Next,to solve the occlusion issues,during the training phase,the C2F-HLAtt module was integrated,which combined high-low frequency aggregation attention,into the YOLO v8 Backbone to perceive occluded objects and introduce an auxiliary reversible branch to retain more effective features.Using comprehensive score regression loss(CSLoss)to reduce the scores of suboptimal boxes and enhance the comprehensive scores of occluded object boxes.Finally,the soft comprehensive score non-maximal suppression(Soft-CS-NMS)algorithm filtered prediction boxes during the inferencing.Testing on the HSBD,HLNC-YOLO achieved a mean average precision(mAP@50)of 87.8%,with a memory footprint of 17.4 MB.This represented an improvement of 7.1,2.2,4.6,and 11 percentage points over YOLO v8,YOLO v9,YOLO v10,and Faster R-CNN,respectively.Research indicated that the HLNC-YOLO accurately identified the behavior of Hu sheep in intensive farming and possessed generalization capabilities,providing technical support for smart farming.展开更多
To investigate the influence of Al-Zn-Mg-Cu alloy with as-homogenized and as-rolled initial microstructures on the tensile flow behavior,isothermal tensile tests were conducted on a GLEEBLE-3500 isothermal simulator a...To investigate the influence of Al-Zn-Mg-Cu alloy with as-homogenized and as-rolled initial microstructures on the tensile flow behavior,isothermal tensile tests were conducted on a GLEEBLE-3500 isothermal simulator at temperatures of 380-440℃and strain rates of 0.05-1 s^(−1).The Johnson-Cook model,Hensel-Spittel model,strain-compensated Arrhenius model,and critical fracture strain model were established.Results show that through the evaluation of the models using the correlation coefficient(R)and the average absolute relative error,the strain-compensated Arrhenius model can represent the flow behavior of the alloy more accurately.Shear bands are more pronounced in the as-homogenized specimens,whereas dynamic recrystallization is predominantly observed in as-rolled specimens.Fracture morphology analysis reveals that a mixed fracture mechanism is prevalent in the as-homogenized specimen,whereas a ductile fracture mechanism is predominant in the as-rolled specimen.The processing maps indicate that the unstable region is reduced in the as-rolled specimens compared with that in the as-homogenized specimens.The optimal hot working windows for the as-homogenized and as-rolled specimens are determined as 410-440℃/0.14-1 s^(−1)and 380-400℃/0.05-0.29 s^(−1),respectively.展开更多
Objectives This study aimed to explore the lagged and cumulative effects of risk factors on disability in older adults using distributed lag non-linear models(DLNMs).Methods We utilized data from the China Health and ...Objectives This study aimed to explore the lagged and cumulative effects of risk factors on disability in older adults using distributed lag non-linear models(DLNMs).Methods We utilized data from the China Health and Retirement Longitudinal Study(CHARLS).After feature selection via Elastic Net Regularization,we applied DLNMs to evaluate the lagged effects of risk factors.Disability was defined as the presence of any difficulties in basic activities of daily living(BADL).The cumulative relative risk(CRR)was calculated by summing the lag-specific risk estimates,representing the cumulative disability risk over the specified lag period.Effect modifications and sensitivity analyses were also performed.Results This study included a total of 2,318 participants.Early-phase lag factors,such as the difficulty in stooping(CRR=3.58;95%CI:2.31-5.55;P<0.001)and walking(CRR=2.77;95%CI:1.39-5.55;P<0.001),exerted the strongest effects immediately upon occurrence.Mid-phase lag factors,such as arthritis(CRR=1.51;95%CI:1.10-2.06;P=0.001),showed a resurgence in disability risk within 2-3 years.Late-phase lag factors,including depressive symptoms(CRR=2.38;95%CI:1.30-4.35;P<0.001)and elevated systolic blood pressure(CRR=1.64;95%CI:1.06-2.79;P=0.02),exhibited significant long-term cumulative risks.Conversely,grip strength(CRR=0.80;95%CI:0.54-0.95;P=0.02)and social participation(CRR=0.89;95%CI:0.73-0.99;P=0.04)were significant protective factors.Conclusions The findings underscore the importance of tailored interventions that account for various lag characteristics of different factors to effectively mitigate disability risk.Future studies should explore the underlying biological and sociological mechanisms of these lagged effects,identify intervention strategies that target risk factors with different lagged patterns,and evaluate their effectiveness.展开更多
In this article,by employing the Hirota bilinear approach and the long wave limit method,we not only derive soliton solutions,lump solutions,and hybrid solutions for the(2+1)-dimensional Yu-Toda-Sasa-Fukuyama(YTSF)equ...In this article,by employing the Hirota bilinear approach and the long wave limit method,we not only derive soliton solutions,lump solutions,and hybrid solutions for the(2+1)-dimensional Yu-Toda-Sasa-Fukuyama(YTSF)equation,but also analyze the dynamical behaviors of nonlinear local wave propagation in shallow water.Firstly,based on the Hirota bilinear approach,one to four-order soliton solutions of the YTSF equation are obtained,and the effects of different parameters on the amplitude,propagation trajectory,and displacement of solitons are investigated.Secondly,using the long wave limit approach,one to three-order lump solutions and various physical quantities of the YTSF equation are derived.It is found that the real and imaginary parts of the parameter pi dominate the propagation trajectory and the shape of lump waves,respectively.Furthermore,we construct the hybrid solution for the YTSF equation,leading to the conclusion that the interaction between lumps and solitons constitutes an elastic collision.To intuitively understand the dynamic behaviors of these solutions,we conduct numerical simulations to present vivid three-dimensional visualizations.展开更多
Correction to:Nano-Micro Letters(2026)18:10.https://doi.org/10.1007/s40820-025-01852-8 Following publication of the original article[1],the authors reported that the last author’s name was inadvertently misspelled.Th...Correction to:Nano-Micro Letters(2026)18:10.https://doi.org/10.1007/s40820-025-01852-8 Following publication of the original article[1],the authors reported that the last author’s name was inadvertently misspelled.The published version showed“Hongzhen Chen”,whereas the correct spelling should be“Hongzheng Chen”.The correct author name has been provided in this Correction,and the original article[1]has been corrected.展开更多
Background:Adolescent suicide remains a pressing public health concern in South Korea and worldwide,ranking as one of the leading causes of death among youth.Identifying modifiable risk and protective factors is criti...Background:Adolescent suicide remains a pressing public health concern in South Korea and worldwide,ranking as one of the leading causes of death among youth.Identifying modifiable risk and protective factors is critical for prevention strategies.Physical activity has been suggested as one such factor due to its potential mental health benefits.This study aimed to examine whether associations between physical activity and suicidality differ by activity type and by stage of suicidal behavior,distinguishing suicidal ideation,planning,and attempts among Korean adolescents.Methods:This cross-sectional secondary analysis used data from the 20th Korea Youth Risk Behavior Web-based Survey(KYRBS)conducted in 2024,a nationally representative survey of Korean adolescents.The study included 54,653 middle and high school students with complete data on physical activity,suicidal ideation,planning,and attempts.Three types of physical activity(vigorous activity,muscle-strengthening activity,and≥60 min of daily physical activity)were examined.Associations with suicidal behaviors were analyzed using multivariable logistic regression models,adjusting for psychological,behavioral,and sociodemographic covariates.Results:In this nationally representative sample of Korean adolescents,engaging in at least 60 min of daily physical activity was significantly associated with lower odds of suicide planning,but not ideation or attempts.In contrast,muscle-strengthening activity was linked to increased odds of both suicide planning and attempts,whereas vigorous activity showed no significant associations.Psychological factors,including generalized anxiety,sadness,stress,and loneliness,showed strong associations with suicidal behaviors and were included as covariates in the adjusted models.Female students,low academic performance,and unstable residential status were also associated with higher odds of suicidal behaviors.Conclusion:The associations between physical activity and suicidality differed by activity type and suicidal outcome;muscle-strengthening activity was positively associated with suicide planning and attempts in adjusted models.展开更多
Residential energy-use behavior and energy-saving awareness play a crucial role in sustainable urban energy planning and building energy efficiency,particularly under the pressures of climate change.However,existing s...Residential energy-use behavior and energy-saving awareness play a crucial role in sustainable urban energy planning and building energy efficiency,particularly under the pressures of climate change.However,existing studies often lack comparative analysis of urban-rural differences and tend to focus excessively on behavior patterns while neglecting the dimension of energysaving awareness.With China’s urbanization rate reaching 66.16%,understanding such regional disparities has become increasingly important.To address these research gaps,this study conducts a large-scale survey on space cooling behaviors among residents in Beijing,a representative Chinese megacity.It should be noted that living standards in such megacities are generally higher than the national average,which may shape distinctive energy-use profiles.Analyzing 1573valid samples(1064 urban/442 rural)in 2024,this study employed K-Prototypes and K-Modes clustering to identify typical cooling behavior and energy-saving awareness pattems,followed by Kendall/Chi-square correlation tests and XGBoost importance analysis to determine key influencing factors,with subsequent urban-rural comparative analysis.Results indicate that urban residents are primarily heat-sensitive or heat-tolerant,with a secondary patten of mid-low temperature preference,and generally exhibit long cooling durations;rural behavior is dominated by heat-tolerant type,followed by heat-sensitive,mid-low temperature preference,and never-on types as secondary patterns;both urban and rural areas exhibit energy-savingawareness characterized by low consumption-lowwillingness,though urban areas show marginally higher motivation;energy-saving awareness correlates with cooling behavior in rural areas,but this relationship weakens significantly in urban contexts.展开更多
Eco-driving behaviors have been recommended around the world because the transport is a key factor of energy use and pollution emissions.Therefore,based on the driving decision model,this paper introduces three aspect...Eco-driving behaviors have been recommended around the world because the transport is a key factor of energy use and pollution emissions.Therefore,based on the driving decision model,this paper introduces three aspects of the driving decisions(strategic decision,tactical decision and operation decision)to analyze the economy of vehicle energy.The analytic hierarchy process(AHP)is used to assign the weight of the internal evaluation indexes,so as to form a complete assessment for drivers'eco-driving behaviors.The research result can not only quantitatively describe the energy-saving effect of drivers'decisions,but also put forward targeted driving suggestions to optimize drivers'eco-driving behaviors.This assessment model helps to clarify the potential of eco-driving on energy economy of transportation in a hierarchical way,and provides a valuable theoretical basis for the further promotion and application of eco-driving education.展开更多
The partial discharge occurring in the weak part of the insulation of a converter transformer results in the formation of a large number of bubbles in the insulating oil.The migration,deformation,and other dynamic beh...The partial discharge occurring in the weak part of the insulation of a converter transformer results in the formation of a large number of bubbles in the insulating oil.The migration,deformation,and other dynamic behaviors of bubbles in the region of a strong electric field can cause them to easily accumulate into“small bridges”of impurities that can lead to breakdown of the oil gap.The authors of this study experimentally investigate and discuss the mechanisms of migration and deformation of bubbles in oil during partial discharge under composite AC/DC voltage to clarify their dynamic behaviors.The influence of the initial position of the bubbles on their trajectory of migration and velocity as well as the morphological changes occurring in them are analyzed using numerical simulations.The results show that the bubbles move away from the strong electric field due to the action of the dielectrophoretic force.The interface of the bubbles is longitudinally stretched under the action of the electrostrictive force and the vertical component of the drag force and gradually recovers to assume a spherical shape under the influence of surface tension and the horizontal component of the drag force.展开更多
With the rapid development of smart manufacturing,intelligent safety monitoring in industrial workshops has become increasingly important.To address the challenges of complex backgrounds,target scale variation,and exc...With the rapid development of smart manufacturing,intelligent safety monitoring in industrial workshops has become increasingly important.To address the challenges of complex backgrounds,target scale variation,and excessive model parameters in worker violation detection,this study proposes ADCP-YOLO,an enhanced lightweight model based on YOLOv8.Here,“ADCP”represents four key improvements:Alterable Kernel Convolution(AKConv),Dilated-Wise Residual(DWR)module,Channel Reconstruction Global Attention Mechanism(CRGAM),and Powerful-IoU loss.These components collaboratively enhance feature extraction,multi-scale perception,and localization accuracy while effectively reducing model complexity and computational cost.Experimental results show that ADCP-YOLO achieves a mAP of 90.6%,surpassing YOLOv8 by 3.0%with a 6.6%reduction in parameters.These findings demonstrate that ADCP-YOLO successfully balances accuracy and efficiency,offering a practical solution for intelligent safety monitoring in smart factory workshops.展开更多
Loess landslides are major hazards in the Chinese Loess Plateau(CLP).The loess in this region is frequently subjected to repeated wetting–drying(W-D)cycles due to climatic factors,which significantly increases the li...Loess landslides are major hazards in the Chinese Loess Plateau(CLP).The loess in this region is frequently subjected to repeated wetting–drying(W-D)cycles due to climatic factors,which significantly increases the likelihood of landslides.Therefore,investigating the shear behavior and microstructural evolution of loess under climate-induced W-D cycles is crucial to understanding the mechanisms of loess landslides.In this study,Malan loess is analyzed using unsaturated triaxial tests,resistivity tests,scanning electron microscopy,and mercury intrusion porosimetry.The test results show that shear strength decreases with increased W-D cycles,and the degradation effect is more pronounced under lower confining pressure.The variations in conductive pathways indicate that electrical resistivity can effectively reflect the structural damage of loess during W-D cycles,which is associated with increased direct point contacts and spaced pores.Aggregation of clay particles and growth of cracks during the W-D cycles can further destabilize the loess microstructure.As the confining pressure increases,crushed particles rearrange and convert spaced pores into intergranular pores.The number and peak intensity of dominant spaced pores decrease,resulting in a more stable structure.This study clarifies the mechanisms of loess landslides under W-D cycles and provides theoretical support for landslide prevention and control in the CLP.展开更多
Objective: To understand the current status of peer caring behavior and empathy among undergraduate nursing students and to explore the relationship between the two. Method: Using the convenience sampling method, a qu...Objective: To understand the current status of peer caring behavior and empathy among undergraduate nursing students and to explore the relationship between the two. Method: Using the convenience sampling method, a questionnaire survey was conducted among 292 nursing students from a medical college in Jiangxi Province, using the Peer Caring Behavior Scale and the Jefferson Scale of Empathy. Results: The score for peer caring behavior among undergraduate nursing students was 85.00 (78.00-92.00), and the score for empathy was 101.00 (92.00-110.00). A positive correlation was found between the two (r = 0.362, p < 0.05). Conclusion: The level of peer caring behavior among undergraduate nursing students is above average, while their empathy level is moderate, with a positive correlation between the two. This suggests that nursing educators should strengthen the development of peer caring behavior, which may help enhance the empathy of undergraduate nursing students.展开更多
This study utilizes wet/dry cyclic corrosion testing combined with corrosion big data technology to investigate the mechanism by which chloride ions(Cl^(-))influence the corrosion behavior of 650 MPa high-strength low...This study utilizes wet/dry cyclic corrosion testing combined with corrosion big data technology to investigate the mechanism by which chloride ions(Cl^(-))influence the corrosion behavior of 650 MPa high-strength low-alloy(HSLA)steel in industrially polluted environments.The corrosion process of 650 MPa HSLA steel occurred in two distinct stages:an initial corrosion stage and a stable corrosion stage.During the initial phase,the weight loss rate increased rapidly owing to the instability of the rust layer.Notably,this study demonstrated that 650 MPa HSLA steel exhibited superior corrosion resistance in Cl-containing environments.The formation of a corrosion-product film eventually reduced the weight-loss rate.However,the intrusion of Cl^(-)at increasing concentrations gradually destabilized theα/γ^(*)phases of the rust layer,leading to a looser structure and lower polarization resistance(R_(p)).The application of corrosion big data technology in this study facilitated the validation and analysis of the experimental results,offering new insights into the corrosion mechanisms of HSLA steel in chloride-rich environments.展开更多
Objective: To analyze the impact of motivational nursing under the solution-focused approach on health behaviors in surgical care for bladder cancer patients. Methods: A sample of 72 bladder cancer patients who underw...Objective: To analyze the impact of motivational nursing under the solution-focused approach on health behaviors in surgical care for bladder cancer patients. Methods: A sample of 72 bladder cancer patients who underwent surgical treatment from September 2024 to September 2025 was randomly divided into groups using a random number table. Group A received motivational nursing under the solution-focused approach, while Group B received conventional nursing. Health behavior scores and complication indicators were compared between the two groups. Results: Group A had higher scores on the Health-Promoting Lifestyle Profile II (HPLP-Ⅱ) than Group B, with p < 0.05. The postoperative complication rate in Group A was lower than that in Group B, with p < 0.05. Conclusion: For bladder cancer patients undergoing surgery, receiving motivational nursing under the solution-focused approach can improve health behaviors, alleviate negative emotions, and is highly feasible and effective.展开更多
The volume change behavior of natural gas hydrate-bearing sediment is essential as it influences settlement,strength,and stiffness,which directly affect the stability of hydrate reservoirs during hydrate extraction or...The volume change behavior of natural gas hydrate-bearing sediment is essential as it influences settlement,strength,and stiffness,which directly affect the stability of hydrate reservoirs during hydrate extraction or in response to environmental changes.The volume change is influenced not only by stress but also by the formation and dissociation of hydrates.This study adopted a customized apparatus for one-dimensional compression tests,allowing independent control of gas pressure and effective stress.Tests were conducted on samples with different hydrate saturations along various temperature-gas pressure-effective stress paths,yielding some conclusions related to compressibility and creep.An unusual phenomenon was observed under low-stress conditions:hydrate formation led to shrinkage rather than expansion.Three potential mechanisms behind this occurrence were discussed.As hydrate saturation increases,the yield stress rises while the compression and swelling indexes remain minimally affected.After hydrate dissociation,the compression curve of hydrate-bearing sediment drops to that of hydrate-free sediment.Once hydrate is formed,the compression curve of hydrate-free sediment gradually approaches that of hydrate-bearing sediment during the subsequent loading.Under low-stress conditions,the creep of both hydrate-free and hydrate-bearing sediments is very weak.However,when stress increases,significantly beyond the yield stress,the creep of both sediments increases significantly,with hydrate-bearing sediment exhibiting much greater creep than hydrate-free sediment.展开更多
Phosphorus tends to migrate into metallic iron during the direct reduction of high-phosphorus oolitic iron ore,leading to undesirable phosphorus enrichment in metallic iron.However,the underlying reduction and migrati...Phosphorus tends to migrate into metallic iron during the direct reduction of high-phosphorus oolitic iron ore,leading to undesirable phosphorus enrichment in metallic iron.However,the underlying reduction and migration mechanisms remain poorly understood.Phosphorus behavior during coal-based reduction was systematically investigated through theoretical modeling and experimental approaches.Thermodynamic analysis revealed that the carbon reduction of solid Ca_(3)(PO_(4))_(2)to gaseous P_(2)requires temperatures exceeding 1400℃.Notably,this threshold significantly decreases to 1130.5℃in the presence of SiO_(2)and Al_(2)O_(3).Further investigations demonstrated that Ca_(3)(PO_(4))_(2)co-reduces with Fe_(x)O_(γ)in the presence of SiO_(2)-Al_(2)O_(3)-Fe_(x)O_(γ),forming Fe_(3)P(instead of gaseous P_(2))at a markedly lower temperature of 778.7℃.Mechanistic studies indicate that the inherent thermal stability of Ca_(3)(PO_(4))_(2)inhibits the generation of reactive[P_(2)O_(5)].However,SiO_(2)-Al_(2)O_(3)coexistence destabilizes Ca_(3)(PO_(4))_(2)while exponentially enhancing[P_(2)O_(5)]activity.This synergistic effect dramatically promotes the phosphorus mineral reduction.Characterization confirmed that Ca_(3)(PO_(4))_(2)migrated into the slag phase(4FeO·Al_(2)O_(3)·3SiO_(2)·CaO·P_(2)O_(5)).Subsequently,the reactive P_(2)O_(5)in slag is reduced with metallic iron to form Fe_(3)P,which further dissolves into theα-Fe matrix through solid-state diffusion,ultimately generating Fe-P solid solutions.展开更多
Flight behavior analysis provides the fundamental basis for the future development of air traffic management(ATM).The characteristics of aircraft behavior are inherently reflected in their flight trajectories,impactin...Flight behavior analysis provides the fundamental basis for the future development of air traffic management(ATM).The characteristics of aircraft behavior are inherently reflected in their flight trajectories,impacting flight efficiency and safety levels.However,existing research largely addresses inefficient or abnormal trajectories from a single perspective,with an absence of a unified evaluation standard.This paper introduces a method for analyzing flight deviation behavior based on automatic dependent surveillance-broadcast(ADS-B)data,defining novel metrics of trajectory redundancy and trajectory deviation.An adaptive detection algorithm is developed to capture diverse deviation patterns.Results reveal that higher trajectory redundancy is linked to lower operational efficiency,while trajectory deviation effectively identify stepped descents,holding patterns,detours,and other behaviors.The approach offers data-driven support for anomaly detection,performance evaluation and air traffic management,with substantial significance for civil aviation applications.展开更多
Urbanization destroys wildlife habitats,fragmenting them into small patches with poor connectivity,leading to population declines in species sensitive to such chan ges.Escape is the most common anti-predator strategy ...Urbanization destroys wildlife habitats,fragmenting them into small patches with poor connectivity,leading to population declines in species sensitive to such chan ges.Escape is the most common anti-predator strategy adopted by birds,refuges in habitats reduce or eliminate predation risk.Therefore,creating habitats with suitable refuges for birds has significant implications for their conservation.However,there have been few studies on refuge selection in birds.This study examined the Eurasian Tree Sparrow(Passer montanus)and Oriental Magpie(Pica serica)in urban and rural areas of Chengde City,northern China by measuring their alert distance(AD),flight initiation distance(FID),an d distance fled(DF)and analyzed their refuge selection characteristics after escaping.The FID/AD ratio was employed to assess the behavioral differences of birds in the risk trade-off.The results showed that the FID and FID/AD of both species were lower in urban areas than in rural areas and were negatively correlated with immediate human density.Sparrow FID was significantly affected by group size and landing substrate type.The FID of sparrows was positively correlated with the group size.The sparrows that fled to bushes escaped earlier.In urban and rural areas,sparrows exhibited significantly lower FID,DF,and FID/AD than magpies.The species adopted different refuge selection strategies,with magpies preferentially selecting trees with greater vertical height and sparrows selecting both trees and bushes.Further analysis indicated that the horizontal and vertical distances fled of both species were lower when fleeing to bushes.Urban planning and conservation areas construction should incorporate the ecological needs of local bird species to rationally configure their habitat structure,thereby optimizing the effect of avian conservation.展开更多
Pile group-supported bridges in liquefied sloping ground with crust are prone to severe damage.However,there remains a limited comprehension of the intricate interactions among pile group,soil,and superstructures,as w...Pile group-supported bridges in liquefied sloping ground with crust are prone to severe damage.However,there remains a limited comprehension of the intricate interactions among pile group,soil,and superstructures,as well as the associated failure mechanisms.To address this issue,this paper presents large-scale shaking table tests conducted on pile group-supported bridges in sloping liquefiable ground with crust to uncover the intricate interaction mechanisms.Firstly,the dynamic characteristics and interaction of the pile-soil-superstructure system were explored.Then,the lateral displacement and acceleration of the superstructure and pile were presented.Next,the curvature and damage characteristics of the pile group-supported bridge were discussed.Finally,through cross-correlation analysis,the study revealed the inertia and kinematic effects,focusing on how the effects influenced the seismic demands.Results indicate that significant differences are observed in pile-soil interactions during strong seismic events depending on the depth and liquefaction stage.As earthquake intensity increases,peak displacement in the superstructure rises linearly while residual displacement grows exponentially.Moreover,the pile group effect becomes more pronounced,especially at the pile head,with the trailing piles showing greater curvature than the leading ones.Due to significant soil lateral spreading and the shadowing effect within the pile group,the leading piles experience prominent kinematic effects from the surface down to the intermediate layer of saturated sand compared to the trailing piles.These findings contribute valuable insights for improving the seismic design approach for bridges with pile groups in sloping liquefied soils.展开更多
In coal mines,dynamic disasters such as rock bursts seriously threaten the safety of mining activities.Exploring the dynamic behaviors and disaster characteristics in the impact failure process of coal serves as the b...In coal mines,dynamic disasters such as rock bursts seriously threaten the safety of mining activities.Exploring the dynamic behaviors and disaster characteristics in the impact failure process of coal serves as the basis and prerequisite for monitoring and warning rock bursts.In this context,impact failure tests of coal were carried out under different axial static loads and impact velocities to analyze the dynamic behaviors and acoustic emission(AE)response characteristics of coal.The results show that the dynamic behaviors of coal under combined dynamic and static loads are significantly different from those under static loads,and the stress-strain curve displays double peaks without an obvious compaction stage.As the axial static load grows,the dynamic strength and peak strain both have a quadratic function with the axial static load.When the coal damage intensifies instantaneously,the AE count and energy parameters both witness pulse-like increases and reach their peak values.The damage effect of axial static loads on coal,though limited,has an extreme point.In contrast,the impact velocity can strengthen the response of AE signals and has linear function relationships with the peak values of AE count and energy.This plays a leading role in the damage to samples and sets a critical point for coal failure and fracture.Compared with the analysis results of stress and strain,the responses of AE signals are more accurate and reliable.Based on AE response characteristics,the damage evolution process of coal under the combined dynamic and static loads can be identified more accurately to reveal the moment corresponding to coal damage and the characteristics of coal failure.The research results are conducive to the further application of AE monitoring methods to early warning of rock burst disasters in coal mining sites.展开更多
文摘Behavior recognition of Hu sheep contributes to their intensive and intelligent farming.Due to the generally high density of Hu sheep farming,severe occlusion occurs among different behaviors and even among sheep performing the same behavior,leading to missing and false detection issues in existing behavior recognition methods.A high-low frequency aggregated attention and negative sample comprehensive score loss and comprehensive score soft non-maximum suppression-YOLO(HLNC-YOLO)was proposed for identifying the behavior of Hu sheep,addressing the issues of missed and erroneous detections caused by occlusion between Hu sheep in intensive farming.Firstly,images of four typical behaviors-standing,lying,eating,and drinking-were collected from the sheep farm to construct the Hu sheep behavior dataset(HSBD).Next,to solve the occlusion issues,during the training phase,the C2F-HLAtt module was integrated,which combined high-low frequency aggregation attention,into the YOLO v8 Backbone to perceive occluded objects and introduce an auxiliary reversible branch to retain more effective features.Using comprehensive score regression loss(CSLoss)to reduce the scores of suboptimal boxes and enhance the comprehensive scores of occluded object boxes.Finally,the soft comprehensive score non-maximal suppression(Soft-CS-NMS)algorithm filtered prediction boxes during the inferencing.Testing on the HSBD,HLNC-YOLO achieved a mean average precision(mAP@50)of 87.8%,with a memory footprint of 17.4 MB.This represented an improvement of 7.1,2.2,4.6,and 11 percentage points over YOLO v8,YOLO v9,YOLO v10,and Faster R-CNN,respectively.Research indicated that the HLNC-YOLO accurately identified the behavior of Hu sheep in intensive farming and possessed generalization capabilities,providing technical support for smart farming.
文摘To investigate the influence of Al-Zn-Mg-Cu alloy with as-homogenized and as-rolled initial microstructures on the tensile flow behavior,isothermal tensile tests were conducted on a GLEEBLE-3500 isothermal simulator at temperatures of 380-440℃and strain rates of 0.05-1 s^(−1).The Johnson-Cook model,Hensel-Spittel model,strain-compensated Arrhenius model,and critical fracture strain model were established.Results show that through the evaluation of the models using the correlation coefficient(R)and the average absolute relative error,the strain-compensated Arrhenius model can represent the flow behavior of the alloy more accurately.Shear bands are more pronounced in the as-homogenized specimens,whereas dynamic recrystallization is predominantly observed in as-rolled specimens.Fracture morphology analysis reveals that a mixed fracture mechanism is prevalent in the as-homogenized specimen,whereas a ductile fracture mechanism is predominant in the as-rolled specimen.The processing maps indicate that the unstable region is reduced in the as-rolled specimens compared with that in the as-homogenized specimens.The optimal hot working windows for the as-homogenized and as-rolled specimens are determined as 410-440℃/0.14-1 s^(−1)and 380-400℃/0.05-0.29 s^(−1),respectively.
基金supported by ScientificResearch Fund of National Health Commission of the People’s Republic of China-Major Science and Technology Program for Medicine and Health in Zhejiang Province(WKJ-ZJ-2406).
文摘Objectives This study aimed to explore the lagged and cumulative effects of risk factors on disability in older adults using distributed lag non-linear models(DLNMs).Methods We utilized data from the China Health and Retirement Longitudinal Study(CHARLS).After feature selection via Elastic Net Regularization,we applied DLNMs to evaluate the lagged effects of risk factors.Disability was defined as the presence of any difficulties in basic activities of daily living(BADL).The cumulative relative risk(CRR)was calculated by summing the lag-specific risk estimates,representing the cumulative disability risk over the specified lag period.Effect modifications and sensitivity analyses were also performed.Results This study included a total of 2,318 participants.Early-phase lag factors,such as the difficulty in stooping(CRR=3.58;95%CI:2.31-5.55;P<0.001)and walking(CRR=2.77;95%CI:1.39-5.55;P<0.001),exerted the strongest effects immediately upon occurrence.Mid-phase lag factors,such as arthritis(CRR=1.51;95%CI:1.10-2.06;P=0.001),showed a resurgence in disability risk within 2-3 years.Late-phase lag factors,including depressive symptoms(CRR=2.38;95%CI:1.30-4.35;P<0.001)and elevated systolic blood pressure(CRR=1.64;95%CI:1.06-2.79;P=0.02),exhibited significant long-term cumulative risks.Conversely,grip strength(CRR=0.80;95%CI:0.54-0.95;P=0.02)and social participation(CRR=0.89;95%CI:0.73-0.99;P=0.04)were significant protective factors.Conclusions The findings underscore the importance of tailored interventions that account for various lag characteristics of different factors to effectively mitigate disability risk.Future studies should explore the underlying biological and sociological mechanisms of these lagged effects,identify intervention strategies that target risk factors with different lagged patterns,and evaluate their effectiveness.
基金Supported by the National Natural Science Foundation of China(12001424,12271324)the Natural Science Basic research program of Shaanxi Province(2021JZ-21)+1 种基金the China Postdoctoral Science Foundation(2020M673332)Xi’an University,Xi’an Science and Technology Plan Wutongshu Technology Transfer Action Innovation Team(25WTZD07)。
文摘In this article,by employing the Hirota bilinear approach and the long wave limit method,we not only derive soliton solutions,lump solutions,and hybrid solutions for the(2+1)-dimensional Yu-Toda-Sasa-Fukuyama(YTSF)equation,but also analyze the dynamical behaviors of nonlinear local wave propagation in shallow water.Firstly,based on the Hirota bilinear approach,one to four-order soliton solutions of the YTSF equation are obtained,and the effects of different parameters on the amplitude,propagation trajectory,and displacement of solitons are investigated.Secondly,using the long wave limit approach,one to three-order lump solutions and various physical quantities of the YTSF equation are derived.It is found that the real and imaginary parts of the parameter pi dominate the propagation trajectory and the shape of lump waves,respectively.Furthermore,we construct the hybrid solution for the YTSF equation,leading to the conclusion that the interaction between lumps and solitons constitutes an elastic collision.To intuitively understand the dynamic behaviors of these solutions,we conduct numerical simulations to present vivid three-dimensional visualizations.
文摘Correction to:Nano-Micro Letters(2026)18:10.https://doi.org/10.1007/s40820-025-01852-8 Following publication of the original article[1],the authors reported that the last author’s name was inadvertently misspelled.The published version showed“Hongzhen Chen”,whereas the correct spelling should be“Hongzheng Chen”.The correct author name has been provided in this Correction,and the original article[1]has been corrected.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(RS-2023-NR076968)the Chung-Ang University Graduate Research Scholarship in 2024.
文摘Background:Adolescent suicide remains a pressing public health concern in South Korea and worldwide,ranking as one of the leading causes of death among youth.Identifying modifiable risk and protective factors is critical for prevention strategies.Physical activity has been suggested as one such factor due to its potential mental health benefits.This study aimed to examine whether associations between physical activity and suicidality differ by activity type and by stage of suicidal behavior,distinguishing suicidal ideation,planning,and attempts among Korean adolescents.Methods:This cross-sectional secondary analysis used data from the 20th Korea Youth Risk Behavior Web-based Survey(KYRBS)conducted in 2024,a nationally representative survey of Korean adolescents.The study included 54,653 middle and high school students with complete data on physical activity,suicidal ideation,planning,and attempts.Three types of physical activity(vigorous activity,muscle-strengthening activity,and≥60 min of daily physical activity)were examined.Associations with suicidal behaviors were analyzed using multivariable logistic regression models,adjusting for psychological,behavioral,and sociodemographic covariates.Results:In this nationally representative sample of Korean adolescents,engaging in at least 60 min of daily physical activity was significantly associated with lower odds of suicide planning,but not ideation or attempts.In contrast,muscle-strengthening activity was linked to increased odds of both suicide planning and attempts,whereas vigorous activity showed no significant associations.Psychological factors,including generalized anxiety,sadness,stress,and loneliness,showed strong associations with suicidal behaviors and were included as covariates in the adjusted models.Female students,low academic performance,and unstable residential status were also associated with higher odds of suicidal behaviors.Conclusion:The associations between physical activity and suicidality differed by activity type and suicidal outcome;muscle-strengthening activity was positively associated with suicide planning and attempts in adjusted models.
文摘Residential energy-use behavior and energy-saving awareness play a crucial role in sustainable urban energy planning and building energy efficiency,particularly under the pressures of climate change.However,existing studies often lack comparative analysis of urban-rural differences and tend to focus excessively on behavior patterns while neglecting the dimension of energysaving awareness.With China’s urbanization rate reaching 66.16%,understanding such regional disparities has become increasingly important.To address these research gaps,this study conducts a large-scale survey on space cooling behaviors among residents in Beijing,a representative Chinese megacity.It should be noted that living standards in such megacities are generally higher than the national average,which may shape distinctive energy-use profiles.Analyzing 1573valid samples(1064 urban/442 rural)in 2024,this study employed K-Prototypes and K-Modes clustering to identify typical cooling behavior and energy-saving awareness pattems,followed by Kendall/Chi-square correlation tests and XGBoost importance analysis to determine key influencing factors,with subsequent urban-rural comparative analysis.Results indicate that urban residents are primarily heat-sensitive or heat-tolerant,with a secondary patten of mid-low temperature preference,and generally exhibit long cooling durations;rural behavior is dominated by heat-tolerant type,followed by heat-sensitive,mid-low temperature preference,and never-on types as secondary patterns;both urban and rural areas exhibit energy-savingawareness characterized by low consumption-lowwillingness,though urban areas show marginally higher motivation;energy-saving awareness correlates with cooling behavior in rural areas,but this relationship weakens significantly in urban contexts.
文摘Eco-driving behaviors have been recommended around the world because the transport is a key factor of energy use and pollution emissions.Therefore,based on the driving decision model,this paper introduces three aspects of the driving decisions(strategic decision,tactical decision and operation decision)to analyze the economy of vehicle energy.The analytic hierarchy process(AHP)is used to assign the weight of the internal evaluation indexes,so as to form a complete assessment for drivers'eco-driving behaviors.The research result can not only quantitatively describe the energy-saving effect of drivers'decisions,but also put forward targeted driving suggestions to optimize drivers'eco-driving behaviors.This assessment model helps to clarify the potential of eco-driving on energy economy of transportation in a hierarchical way,and provides a valuable theoretical basis for the further promotion and application of eco-driving education.
基金supported by the National Natural Science Foundation of China(No.U1966209)the State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(NCEPU,LAPS22001).
文摘The partial discharge occurring in the weak part of the insulation of a converter transformer results in the formation of a large number of bubbles in the insulating oil.The migration,deformation,and other dynamic behaviors of bubbles in the region of a strong electric field can cause them to easily accumulate into“small bridges”of impurities that can lead to breakdown of the oil gap.The authors of this study experimentally investigate and discuss the mechanisms of migration and deformation of bubbles in oil during partial discharge under composite AC/DC voltage to clarify their dynamic behaviors.The influence of the initial position of the bubbles on their trajectory of migration and velocity as well as the morphological changes occurring in them are analyzed using numerical simulations.The results show that the bubbles move away from the strong electric field due to the action of the dielectrophoretic force.The interface of the bubbles is longitudinally stretched under the action of the electrostrictive force and the vertical component of the drag force and gradually recovers to assume a spherical shape under the influence of surface tension and the horizontal component of the drag force.
基金TheNationalNatural Science Foundation ofChina(Nos.62272418,62102058)Zhejiang Provincial Natural Science Foundation Major Project(No.LD24F020004)the Major Open Project of Key Laboratory for Advanced Design and Intelligent Computing of the Ministry of Education(No.ADIC2023ZD001).
文摘With the rapid development of smart manufacturing,intelligent safety monitoring in industrial workshops has become increasingly important.To address the challenges of complex backgrounds,target scale variation,and excessive model parameters in worker violation detection,this study proposes ADCP-YOLO,an enhanced lightweight model based on YOLOv8.Here,“ADCP”represents four key improvements:Alterable Kernel Convolution(AKConv),Dilated-Wise Residual(DWR)module,Channel Reconstruction Global Attention Mechanism(CRGAM),and Powerful-IoU loss.These components collaboratively enhance feature extraction,multi-scale perception,and localization accuracy while effectively reducing model complexity and computational cost.Experimental results show that ADCP-YOLO achieves a mAP of 90.6%,surpassing YOLOv8 by 3.0%with a 6.6%reduction in parameters.These findings demonstrate that ADCP-YOLO successfully balances accuracy and efficiency,offering a practical solution for intelligent safety monitoring in smart factory workshops.
基金supported by the National Natural Science Foundation of China(Grant Nos.42177138 and 41907239)the Central Guidance Funds for Local Science and Technology Development of China(Grant No.YDZJSX2025D031).
文摘Loess landslides are major hazards in the Chinese Loess Plateau(CLP).The loess in this region is frequently subjected to repeated wetting–drying(W-D)cycles due to climatic factors,which significantly increases the likelihood of landslides.Therefore,investigating the shear behavior and microstructural evolution of loess under climate-induced W-D cycles is crucial to understanding the mechanisms of loess landslides.In this study,Malan loess is analyzed using unsaturated triaxial tests,resistivity tests,scanning electron microscopy,and mercury intrusion porosimetry.The test results show that shear strength decreases with increased W-D cycles,and the degradation effect is more pronounced under lower confining pressure.The variations in conductive pathways indicate that electrical resistivity can effectively reflect the structural damage of loess during W-D cycles,which is associated with increased direct point contacts and spaced pores.Aggregation of clay particles and growth of cracks during the W-D cycles can further destabilize the loess microstructure.As the confining pressure increases,crushed particles rearrange and convert spaced pores into intergranular pores.The number and peak intensity of dominant spaced pores decrease,resulting in a more stable structure.This study clarifies the mechanisms of loess landslides under W-D cycles and provides theoretical support for landslide prevention and control in the CLP.
基金2024 University-level Research Project of Fuzhou Medical College,Fuzhou Medical College of Nanchang University(Project No.:fykj202406)。
文摘Objective: To understand the current status of peer caring behavior and empathy among undergraduate nursing students and to explore the relationship between the two. Method: Using the convenience sampling method, a questionnaire survey was conducted among 292 nursing students from a medical college in Jiangxi Province, using the Peer Caring Behavior Scale and the Jefferson Scale of Empathy. Results: The score for peer caring behavior among undergraduate nursing students was 85.00 (78.00-92.00), and the score for empathy was 101.00 (92.00-110.00). A positive correlation was found between the two (r = 0.362, p < 0.05). Conclusion: The level of peer caring behavior among undergraduate nursing students is above average, while their empathy level is moderate, with a positive correlation between the two. This suggests that nursing educators should strengthen the development of peer caring behavior, which may help enhance the empathy of undergraduate nursing students.
基金financially supported by the National Natural Science Foundation of China(Nos.52104319 and 52374323)。
文摘This study utilizes wet/dry cyclic corrosion testing combined with corrosion big data technology to investigate the mechanism by which chloride ions(Cl^(-))influence the corrosion behavior of 650 MPa high-strength low-alloy(HSLA)steel in industrially polluted environments.The corrosion process of 650 MPa HSLA steel occurred in two distinct stages:an initial corrosion stage and a stable corrosion stage.During the initial phase,the weight loss rate increased rapidly owing to the instability of the rust layer.Notably,this study demonstrated that 650 MPa HSLA steel exhibited superior corrosion resistance in Cl-containing environments.The formation of a corrosion-product film eventually reduced the weight-loss rate.However,the intrusion of Cl^(-)at increasing concentrations gradually destabilized theα/γ^(*)phases of the rust layer,leading to a looser structure and lower polarization resistance(R_(p)).The application of corrosion big data technology in this study facilitated the validation and analysis of the experimental results,offering new insights into the corrosion mechanisms of HSLA steel in chloride-rich environments.
文摘Objective: To analyze the impact of motivational nursing under the solution-focused approach on health behaviors in surgical care for bladder cancer patients. Methods: A sample of 72 bladder cancer patients who underwent surgical treatment from September 2024 to September 2025 was randomly divided into groups using a random number table. Group A received motivational nursing under the solution-focused approach, while Group B received conventional nursing. Health behavior scores and complication indicators were compared between the two groups. Results: Group A had higher scores on the Health-Promoting Lifestyle Profile II (HPLP-Ⅱ) than Group B, with p < 0.05. The postoperative complication rate in Group A was lower than that in Group B, with p < 0.05. Conclusion: For bladder cancer patients undergoing surgery, receiving motivational nursing under the solution-focused approach can improve health behaviors, alleviate negative emotions, and is highly feasible and effective.
基金supported by the National Natural Science Foundation of China(Grant No.42171135)the Science and Technology Program of CNOOC Research Institute(Grant No.2023OTKK03)the“CUG Scholar”Scientific Research Funds at China University of Geosciences(Project No.2022098).
文摘The volume change behavior of natural gas hydrate-bearing sediment is essential as it influences settlement,strength,and stiffness,which directly affect the stability of hydrate reservoirs during hydrate extraction or in response to environmental changes.The volume change is influenced not only by stress but also by the formation and dissociation of hydrates.This study adopted a customized apparatus for one-dimensional compression tests,allowing independent control of gas pressure and effective stress.Tests were conducted on samples with different hydrate saturations along various temperature-gas pressure-effective stress paths,yielding some conclusions related to compressibility and creep.An unusual phenomenon was observed under low-stress conditions:hydrate formation led to shrinkage rather than expansion.Three potential mechanisms behind this occurrence were discussed.As hydrate saturation increases,the yield stress rises while the compression and swelling indexes remain minimally affected.After hydrate dissociation,the compression curve of hydrate-bearing sediment drops to that of hydrate-free sediment.Once hydrate is formed,the compression curve of hydrate-free sediment gradually approaches that of hydrate-bearing sediment during the subsequent loading.Under low-stress conditions,the creep of both hydrate-free and hydrate-bearing sediments is very weak.However,when stress increases,significantly beyond the yield stress,the creep of both sediments increases significantly,with hydrate-bearing sediment exhibiting much greater creep than hydrate-free sediment.
基金supported by the National Key Research and Development Program of China(Nos.2023YFC3903900 and 2023YFC3903904)the National Natural Science Foundation Youth Foundation of China(No.52404356)the China Baowu Low Carbon Metallurgy Innovation Foundation(No.BWLCF202216)。
文摘Phosphorus tends to migrate into metallic iron during the direct reduction of high-phosphorus oolitic iron ore,leading to undesirable phosphorus enrichment in metallic iron.However,the underlying reduction and migration mechanisms remain poorly understood.Phosphorus behavior during coal-based reduction was systematically investigated through theoretical modeling and experimental approaches.Thermodynamic analysis revealed that the carbon reduction of solid Ca_(3)(PO_(4))_(2)to gaseous P_(2)requires temperatures exceeding 1400℃.Notably,this threshold significantly decreases to 1130.5℃in the presence of SiO_(2)and Al_(2)O_(3).Further investigations demonstrated that Ca_(3)(PO_(4))_(2)co-reduces with Fe_(x)O_(γ)in the presence of SiO_(2)-Al_(2)O_(3)-Fe_(x)O_(γ),forming Fe_(3)P(instead of gaseous P_(2))at a markedly lower temperature of 778.7℃.Mechanistic studies indicate that the inherent thermal stability of Ca_(3)(PO_(4))_(2)inhibits the generation of reactive[P_(2)O_(5)].However,SiO_(2)-Al_(2)O_(3)coexistence destabilizes Ca_(3)(PO_(4))_(2)while exponentially enhancing[P_(2)O_(5)]activity.This synergistic effect dramatically promotes the phosphorus mineral reduction.Characterization confirmed that Ca_(3)(PO_(4))_(2)migrated into the slag phase(4FeO·Al_(2)O_(3)·3SiO_(2)·CaO·P_(2)O_(5)).Subsequently,the reactive P_(2)O_(5)in slag is reduced with metallic iron to form Fe_(3)P,which further dissolves into theα-Fe matrix through solid-state diffusion,ultimately generating Fe-P solid solutions.
基金supported in part by the National Key Research and Development Program of China(No.2023YFB4302903)the Fundamental Research Funds for the Central Universities(No.210525001464)。
文摘Flight behavior analysis provides the fundamental basis for the future development of air traffic management(ATM).The characteristics of aircraft behavior are inherently reflected in their flight trajectories,impacting flight efficiency and safety levels.However,existing research largely addresses inefficient or abnormal trajectories from a single perspective,with an absence of a unified evaluation standard.This paper introduces a method for analyzing flight deviation behavior based on automatic dependent surveillance-broadcast(ADS-B)data,defining novel metrics of trajectory redundancy and trajectory deviation.An adaptive detection algorithm is developed to capture diverse deviation patterns.Results reveal that higher trajectory redundancy is linked to lower operational efficiency,while trajectory deviation effectively identify stepped descents,holding patterns,detours,and other behaviors.The approach offers data-driven support for anomaly detection,performance evaluation and air traffic management,with substantial significance for civil aviation applications.
基金funded by the Natural Science Foundation of Hebei Province(C2025201032 to J.W.)High-Level Talents Research Start-Up Project of Hebei University(521100222044 to J.W.)+1 种基金the Huizhi Lead Innovation Space Project in High-tech Zone of Chengde City(HZLC202410 to L.M.)National Undergraduate Innovation and Entrepreneurship Training Program(202510098011 to H.Z.)。
文摘Urbanization destroys wildlife habitats,fragmenting them into small patches with poor connectivity,leading to population declines in species sensitive to such chan ges.Escape is the most common anti-predator strategy adopted by birds,refuges in habitats reduce or eliminate predation risk.Therefore,creating habitats with suitable refuges for birds has significant implications for their conservation.However,there have been few studies on refuge selection in birds.This study examined the Eurasian Tree Sparrow(Passer montanus)and Oriental Magpie(Pica serica)in urban and rural areas of Chengde City,northern China by measuring their alert distance(AD),flight initiation distance(FID),an d distance fled(DF)and analyzed their refuge selection characteristics after escaping.The FID/AD ratio was employed to assess the behavioral differences of birds in the risk trade-off.The results showed that the FID and FID/AD of both species were lower in urban areas than in rural areas and were negatively correlated with immediate human density.Sparrow FID was significantly affected by group size and landing substrate type.The FID of sparrows was positively correlated with the group size.The sparrows that fled to bushes escaped earlier.In urban and rural areas,sparrows exhibited significantly lower FID,DF,and FID/AD than magpies.The species adopted different refuge selection strategies,with magpies preferentially selecting trees with greater vertical height and sparrows selecting both trees and bushes.Further analysis indicated that the horizontal and vertical distances fled of both species were lower when fleeing to bushes.Urban planning and conservation areas construction should incorporate the ecological needs of local bird species to rationally configure their habitat structure,thereby optimizing the effect of avian conservation.
基金supported by the National Natural Science Foundation of China(Grant No.52408513)the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(Grant No.GZB20240153)the China Postdoctoral Science Foundation(Grant No.2024M760465).
文摘Pile group-supported bridges in liquefied sloping ground with crust are prone to severe damage.However,there remains a limited comprehension of the intricate interactions among pile group,soil,and superstructures,as well as the associated failure mechanisms.To address this issue,this paper presents large-scale shaking table tests conducted on pile group-supported bridges in sloping liquefiable ground with crust to uncover the intricate interaction mechanisms.Firstly,the dynamic characteristics and interaction of the pile-soil-superstructure system were explored.Then,the lateral displacement and acceleration of the superstructure and pile were presented.Next,the curvature and damage characteristics of the pile group-supported bridge were discussed.Finally,through cross-correlation analysis,the study revealed the inertia and kinematic effects,focusing on how the effects influenced the seismic demands.Results indicate that significant differences are observed in pile-soil interactions during strong seismic events depending on the depth and liquefaction stage.As earthquake intensity increases,peak displacement in the superstructure rises linearly while residual displacement grows exponentially.Moreover,the pile group effect becomes more pronounced,especially at the pile head,with the trailing piles showing greater curvature than the leading ones.Due to significant soil lateral spreading and the shadowing effect within the pile group,the leading piles experience prominent kinematic effects from the surface down to the intermediate layer of saturated sand compared to the trailing piles.These findings contribute valuable insights for improving the seismic design approach for bridges with pile groups in sloping liquefied soils.
基金Open Fund of State Key Laboratory of Coal Mine Disaster Dynamics and Control,Grant/Award Number:2011DA105287-FW202306Postgraduate Research&Practice Innovation Program of Jiangsu Province,Grant/Award Number:KYCX24_2925+4 种基金Fundamental Research Program of Xuzhou,Grant/Award Number:KC23017National Natural Science Foundation of China,Grant/Award Number:52104234Fundamental Research Funds for the Central Universities,Grant/Award Number:2024-10962National Science Foundation for Young Scientists of Jiangsu Province,Grant/Award Number:BK20200657Graduate Innovation Program of China University of Mining and Technology,Grant/Award Number:2024WLKXJ152。
文摘In coal mines,dynamic disasters such as rock bursts seriously threaten the safety of mining activities.Exploring the dynamic behaviors and disaster characteristics in the impact failure process of coal serves as the basis and prerequisite for monitoring and warning rock bursts.In this context,impact failure tests of coal were carried out under different axial static loads and impact velocities to analyze the dynamic behaviors and acoustic emission(AE)response characteristics of coal.The results show that the dynamic behaviors of coal under combined dynamic and static loads are significantly different from those under static loads,and the stress-strain curve displays double peaks without an obvious compaction stage.As the axial static load grows,the dynamic strength and peak strain both have a quadratic function with the axial static load.When the coal damage intensifies instantaneously,the AE count and energy parameters both witness pulse-like increases and reach their peak values.The damage effect of axial static loads on coal,though limited,has an extreme point.In contrast,the impact velocity can strengthen the response of AE signals and has linear function relationships with the peak values of AE count and energy.This plays a leading role in the damage to samples and sets a critical point for coal failure and fracture.Compared with the analysis results of stress and strain,the responses of AE signals are more accurate and reliable.Based on AE response characteristics,the damage evolution process of coal under the combined dynamic and static loads can be identified more accurately to reveal the moment corresponding to coal damage and the characteristics of coal failure.The research results are conducive to the further application of AE monitoring methods to early warning of rock burst disasters in coal mining sites.
