Aims and scope GeoSus encourages wider analysis and innovative thinking about global and regional sustainability by bridging and synthesising natural and human sciences.GeoSus welcomes original,high-quality research a...Aims and scope GeoSus encourages wider analysis and innovative thinking about global and regional sustainability by bridging and synthesising natural and human sciences.GeoSus welcomes original,high-quality research articles,review articles,short communications,technical comments,perspective articles and editorials on the following themes.展开更多
China’s coastal regions,characterized by dense populations and industrial agglomeration,face escalating threats from typhoon disasters.Understanding the evolution of socio-economic exposure to future typhoon landfall...China’s coastal regions,characterized by dense populations and industrial agglomeration,face escalating threats from typhoon disasters.Understanding the evolution of socio-economic exposure to future typhoon landfalls under global change is critical for effective disaster risk management.This study utilizes future typhoon track data simulated by the regional climate model version 4(RegCM4),combined with projected population and Gross Domestic Product(GDP)data for China’s coastal regions under three Shared Socioeconomic Pathways(SSPs:SSP1,sustainability;SSP2,middle of the road;SSP5,fossil-fueled development).We analyze typhoon impact zones for future periods(2030s,2050s,and 2090s)under Representative Concentration Pathways(RCPs:RCP2.6,RCP4.5,and RCP8.5,representing low,medium,and high greenhouse gas emission scenarios,respectively).Exposure levels for 2030,2050,and 2100 are calculated based on the annual average frequency of typhoon impacts during these periods,aiming to quantify the distribution characteristics of typhoon-affected population and GDP in China’s coastal regions.Key findings reveal two high-frequency typhoon im-pact zones:the Taiwan Strait region and the northern Qiongzhou Strait region.Furthermore,under RCP2.6,typhoon impacts may ex-tend to Liaoning,while RCP4.5 and RCP8.5 scenarios indicate potential impacts reaching further north to Heilongjiang.Under RCP4.5,Northeast China will experience the largest typhoon-affected area(43.800×10^(4) km^(2))by the 2030s.High population and GDP exposure concentrates in the Yangtze River Delta,the Pearl River Delta,and the Taiwan Strait coastal areas.Notably,Liaoning’s cumulative ex-posed population may exceed 0.100×10^(8) by 2030 and 2050 under RCP4.5 and RCP8.5 due to typhoon track migration.Given China’s location within the Western Pacific typhoon high-incidence region,the northward expansion of impacts will substantially escalate socio-economic exposure in mid-latitude regions previously at lower risk.These findings underscore the imperative for enhanced disaster pre-vention,mitigation strategies and targeted countermeasure research.展开更多
BACKGROUND Major depressive disorder(MDD)and obesity(OB)are bidirectionally comorbid conditions with common neurobiological underpinnings.However,the neurocognitive mechanisms of their comorbidity remain poorly unders...BACKGROUND Major depressive disorder(MDD)and obesity(OB)are bidirectionally comorbid conditions with common neurobiological underpinnings.However,the neurocognitive mechanisms of their comorbidity remain poorly understood.AIM To examine regional abnormalities in spontaneous brain activity among patients with MDD-OB comorbidity.METHODS This study adopted a regional homogeneity(ReHo)analysis of resting-state functional magnetic resonance imaging.The study included 149 hospital patients divided into four groups:Patients experiencing their first episode of drug-naive MDD with OB,patients with MDD without OB,and age-and sex-matched healthy individuals with and without OB.Whole-brain ReHo analysis was conducted using SPM12 software and RESTplus toolkits,with group comparisons via ANOVA and post-hoc tests.Correlations between ReHo values and behavioral measures were examined.RESULTS ANOVA revealed significant whole-brain ReHo differences among the four groups in four key regions:The left middle temporal gyrus(MTG.L),right cuneus,left precuneus,and left thalamus.Post-hoc analyses confirmed pairwise differences between all groups across these regions(P<0.05).OB was associated with ReHo alterations in the MTG.L,right cuneus,and left thalamus,whereas abnormalities in the precuneus suggested synergistic pathological mechanisms between MDD and OB.Statistically significant correlations were found between the drive and fun-seeking dimensions of the behavioral activation system,as well as behavioral inhibition and the corresponding ReHo values.CONCLUSION Our findings provide novel evidence for the neuroadaptive mechanisms underlying the MDD-OB comorbidity.Further validation could lead to personalized interventions targeting MTG.L hyperactivity and targeting healthy food cues.展开更多
The metastatic pattern of colon cancer is typically well characterized,with initial dissemination occurring through regional lymphatics,followed by hematogenous spread.The most frequent sites of metastasis in colorect...The metastatic pattern of colon cancer is typically well characterized,with initial dissemination occurring through regional lymphatics,followed by hematogenous spread.The most frequent sites of metastasis in colorectal cancer(CRC)include regional lymph nodes(50%–70%),liver(35%–50%),lungs(21%),peritoneum(15%),and ovaries(13%).1 Isolated distant lymph node metastasis,particularly in the absence of concurrent systemic disease,is exceedingly rare in CRC.To date,only six cases of isolated axillary lymph node metastasis(ALNM)from colorectal primaries have been documented in the literature.1–6 Even more uncommon is the incidental discovery of malignant cells in anastomotic doughnuts following stoma reversal procedures.Herein,we report a rare case involving both the incidental histopathological detection of tumor cells within doughnuts during stoma closure and the subsequent development of isolated ALNM after curative resection of sigmoid colon carcinoma.展开更多
Discriminative region localization and efficient feature encoding are crucial for fine-grained object recognition.However,existing data augmentation methods struggle to accurately locate discriminative regions in comp...Discriminative region localization and efficient feature encoding are crucial for fine-grained object recognition.However,existing data augmentation methods struggle to accurately locate discriminative regions in complex backgrounds,small target objects,and limited training data,leading to poor recognition.Fine-grained images exhibit“small inter-class differences,”and while second-order feature encoding enhances discrimination,it often requires dual Convolutional Neural Networks(CNN),increasing training time and complexity.This study proposes a model integrating discriminative region localization and efficient second-order feature encoding.By ranking feature map channels via a fully connected layer,it selects high-importance channels to generate an enhanced map,accurately locating discriminative regions.Cropping and erasing augmentations further refine recognition.To improve efficiency,a novel second-order feature encoding module generates an attention map from the fourth convolutional group of Residual Network 50 layers(ResNet-50)and multiplies it with features from the fifth group,producing second-order features while reducing dimensionality and training time.Experiments on Caltech-University of California,San Diego Birds-200-2011(CUB-200-2011),Stanford Car,and Fine-Grained Visual Classification of Aircraft(FGVC Aircraft)datasets show state-of-the-art accuracy of 88.9%,94.7%,and 93.3%,respectively.展开更多
Waves are important physical phenomena in an ocean,and their accurate prediction is essential for ocean engineering,maritime traffic,and marine early warning systems.This study focuses on the Qinhuangdao Sea area loca...Waves are important physical phenomena in an ocean,and their accurate prediction is essential for ocean engineering,maritime traffic,and marine early warning systems.This study focuses on the Qinhuangdao Sea area located in the Bohai Sea,China.Herein,we use on-site wind data to correct the reanalysis wind data obtained from the European Centre for Medium-Range Weather Forecasts(ECMWF),improving the accuracy of boundary conditions.Then,we use the Simulating WAves Nearshore(SWAN)model to simulate the regional wave field over time.A regional wave-parameter prediction model is then developed using a limited number of sampled data(covering only 2 years,2020–2021);the model is based on the Whale Optimization Algorithm(WOA),convolutional neural networks(CNNs),and long short-term memory(LSTM)neural networks.WOA is used to optimize the CNN and LSTM framework;in this framework,CNN extracts spatial features,and the LSTM network captures temporal features,enabling accurate short and long-term predictions of wave height,period,and direction.The experimental results showed that despite the small sample size,the model achieves a goodness of fit of 0.9957 for wave height prediction,0.9973 for period,and 0.9749 for wave direction in short-term forecasting.As the prediction step size increases,the accuracy of the model decreases.When the prediction step size reaches 9 h,the root mean square error for the prediction of wave height,period,and direction increases to 0.2060 m,0.4582 s,and32.5358°,respectively.The reliability and applicability of the model are further validated by the experimental results.Our findings highlighted the potential of the developed model in operational wave forecasting,even with a limited number of sampled data.展开更多
The Xinjiang region is situated between the Tethyan and Central Asian orogenic belts.It has undergone multiple episodes of accretionary orogenesis and was tectonically reactivated during the Cenozoic by the far-field ...The Xinjiang region is situated between the Tethyan and Central Asian orogenic belts.It has undergone multiple episodes of accretionary orogenesis and was tectonically reactivated during the Cenozoic by the far-field compressional effects of the India-Eurasia continental collision.These processes have generated pronounced seismicity and recurrent earthquake-related hazards in this region.A high-resolution three-dimensional velocity model is essential for multi-scale velocity model construction,source-parameter inversion,simulation of strong ground motion,and seismic hazard assessment.In this study,we collected first-arrival body-wave travel-time data recorded by permanent stations in and around Xinjiang and processed both ambient-noise and regional-earthquake surface-wave records.The resulting dataset comprises~8.1 million body-wave travel-time picks-including absolute arrival times and event-pair differential times-and~5,000 surface-wave dispersion curves(5-50 s period).By joint inversion of these complementary body and surface wave datasets,we determined a high-resolution three-dimensional V_(p) and V_(s) model for the crust and uppermost mantle beneath Xinjiang(XJVM-1.0)with a lateral resolution of 50-100 km and a vertical resolution of~10 km.XJVM-1.0 reveals that the Tianshan orogen exhibits a relatively rigid upper crust that hosts abundant seismicity under far-field compression,whereas its middle-lower crust accommodates the majority of compressional stress through plastic deformation and/or partial melting.In contrast,the interiors of the Junggar and Tarim basins have experienced negligible internal deformation and are inferred to underthrust beneath the Tianshan orogen in response to the India-Eurasia collision.Relocated seismicity indicates that earthquakes are predominantly concentrated within the Tianshan range,with a notable proportion occurring in the middle-lower crust,implying whole-crust tectonic activity and highlighting the potential for great earthquakes in this region.展开更多
The editors of International Journal of Ophthalmology gratefully acknowledge the members of IJO Editorial Board and reviewers from 51 countries and regions who participated in the peer-reviews and provided their valua...The editors of International Journal of Ophthalmology gratefully acknowledge the members of IJO Editorial Board and reviewers from 51 countries and regions who participated in the peer-reviews and provided their valuable comments between Nov.1st,2024 and Oct.31st,2025.They volunteer their valuable time and expertise,and without them we would not maintain the necessary quality expected of the journal.We apologize if we have inadvertently missed a reviewer’s name off this list.展开更多
Contemporary Social Sciences publishes outstanding research in the field of social sciences in China and also includes high-quality research work by foreign scholars on the development of China’s western regions and ...Contemporary Social Sciences publishes outstanding research in the field of social sciences in China and also includes high-quality research work by foreign scholars on the development of China’s western regions and its reform and opening up.The aim is to help promote China’s academic achievements to the world and give China a stronger voice in the global community of social sciences.The scopes of research fields for consideration include,but not limited to political science,economics,literature,linguistics,journalism and communication,education,sociology,philosophy,history,law,and interdisciplinary research.展开更多
Drought influences carbon fixation by plants.Therefore,elucidating its impact on carbon fluxes in plants at the ecosystem level is crucial for assessing their role in mitigating climate change.Using carbon fluxes and ...Drought influences carbon fixation by plants.Therefore,elucidating its impact on carbon fluxes in plants at the ecosystem level is crucial for assessing their role in mitigating climate change.Using carbon fluxes and environmental factor data from FLUXNET sites,we analyzed the influence of drought on carbon fluxes,their drivers,time-lag effects,and recovery times across various climatic regions and seasons.Results showed drought significantly decreased gross primary production(GPP),ecosystem respiration,and net ecosystem productivity in arid regions but slightly increased carbon sequestration in humid regions.Summer droughts negatively affected vegetation carbon fluxes,partly offset by the positive impact of spring droughts.Nonforest carbon fluxes were more susceptible to drought effects than forest fluxes.Soil water content(SWC)was the main influence on changes in arid regions,whereas vapor pressure deficit(VPD)dominated humid regions.Decreased SWC and increased VPD reduced carbon sequestration in arid regions but increased it in humid regions.Increased VPD reduced GPP,leading to forest carbon loss,whereas decreased SWC reduced GPP,leading to nonforest carbon loss.The lag time of the drought effects on carbon fluxes was longer in humid regions(19.44 d)than in arid regions(14.71 d).Compared to nonforest areas(16.74 d and 57 d for drought lag and recovery time,respectively),forest areas had a longer lag(18.81 d)and recovery time(92 d).The findings revealed discrepancies in the main factors regulating vegetation carbon fluxes during droughts between arid and humid regions and between forest and nonforest ecosystems.These insights provide a new perspective on understanding and simulating carbon-climate feedback.Enhancing ecosystem diversity is a feasible measure to increase drought resistance.展开更多
Background:Social connection is widely recognized as a protective determinant of health,yet its direct and indirect effects on mental health remain underexplored.This study examines the relationship between social con...Background:Social connection is widely recognized as a protective determinant of health,yet its direct and indirect effects on mental health remain underexplored.This study examines the relationship between social connection and mental health,focusing on the mediating role of quality of life(QoL)and the moderating effect of regional differences.Methods:We analyzed data from the 2019 Korean Community Health Survey,comprising 229,099 adults.Mental health was assessed through validated measures of depressive symptoms and psychological well-being.Social connection was measured using indicators of interpersonal ties and community participation,and QoL was assessed via self-reported health-related satisfaction across major life domains.Analytical procedures included mediation modeling and subgroup analyses by region,with significance levels set at p<0.05.Results:The results indicate that social connections are significantly associated with lower stress levels and reduced depressive symptoms,with QoL playing a critical mediating role.Notably,the indirect effect of social connection on mental health via QoL is stronger in rural areas compared to urban regions,highlighting the importance of social cohesion and community support in mental well-being.Among 203,567 adults,greater social participation was associated with lower subjective stress(total effect=−0.052,p<0.001)and fewer depressive symptoms(PHQ-9 total effect=−0.308,p<0.001).QoL significantly mediated these associations,with the strongest indirect pathways observed through usual activities(19.2%for stress;27.6%for depression)and mobility(24.4%for depression).Regional analysis showed stronger mediation in rural areas(up to 26.8%for stress and 32.6%for depression)than in urban areas(8–16%and 14.9–23%).Direct effects remained significant,indicating partial mediation.These findings highlight that social participation enhances mental health directly and indirectly through QoL,particularly in rural contexts.Conclusions:Social connection contributes to better mental health both directly and indirectly through improved QoL,with stronger effects observed in rural communities.These findings highlight the importance of fostering social cohesion and enhancing life quality as strategies for improving population mental health.Policy interventions should adopt context-sensitive approaches that account for regional differences in social resources and service availability.展开更多
The Jiao-Liao-Ji Belt within the North China Craton had undergone a complex tectonic evolution,marked by extensive Paleoproterozoic magmatism that produced a diverse range of mafic to felsic magmatic rocks.These event...The Jiao-Liao-Ji Belt within the North China Craton had undergone a complex tectonic evolution,marked by extensive Paleoproterozoic magmatism that produced a diverse range of mafic to felsic magmatic rocks.These events provide valuable geological records for understanding the tectonic evolution of the Jiao-Liao-Ji Belt.This study focuses on the Paleoproterozoic Chibaisong meta-gabbro in southern Jilin,investigating the source of mafic magma,petrogenesis,and tectonic setting through systematic petrological analysis,zircon U-Pb dating,and geochemical studies.The findings contribute to constraining the dynamic mechanisms of Paleoproterozoic extensional rifting in the Jiao-Liao-Ji orogenic belt.Geochemical data indicate that the samples exhibit low SiO₂(47.99–50.66 wt.%),TiO₂(0.75–3.20 wt.%),Nb(3.22–8.09 ppm),and Ta(0.22–0.51 ppm)contents,along with high TFeO₃(11.97–15.82 wt.%)and MgO(5.67–12.66 wt.%)concentrations.They also show low Nb/La ratios and high(Th/Nb)N values,consistent with the geochemical characteristics of tholeiitic basalts.The samples display low total rare earth element concentrations,weak or absent Eu anomalies,slight enrichment in light rare earth elements,relatively flat heavy rare earth element patterns,and depletion in Nb,Ta,and Ti.The meta-gabbro from southern Jilin exhibits geochemical similarities to Paleoproterozoic metamafic rocks from other regions of the Jiao-Liao-Ji Belt,resembling enriched mid-ocean ridge basalts(E-MORB)with Nb,Ta,and Ti depletion.Integration of previous studies and geochemical data suggests that the 2.16–2.10 Ga metamafic rocks in the Jiao-Liao-Ji Belt experienced contamination by older crustal material.These results indicate that the 2.16–2.10 Ga metamafic rocks are unlikely to be associated with island arc,continental arc,or mid-ocean ridge settings.Instead,they are more likely related to intraplate magmatism associated with continental rifting.展开更多
Unmanned aerial vehicles(UAVs)are widely utilized in area coverage tasks due to their flexibility and efficiency in geo-graphic information acquisition.However,complex boundary conditions in actual water area maps oft...Unmanned aerial vehicles(UAVs)are widely utilized in area coverage tasks due to their flexibility and efficiency in geo-graphic information acquisition.However,complex boundary conditions in actual water area maps often reduce coverage efficiency.To address this issue,this paper proposes a map preprocessing algorithm that linearizes boundary lines and processes concave areas into concave polygons,followed by gridding the map.Additionally,a collaborative area coverage method for UAV swarms is introduced based on region partitioning,which considers the comprehensive cost of energy consumption and time.An improved Hungarian algorithm is utilized for region partitioning,and a Dubins-A*-based plow-ing area full coverage path planning method is proposed to achieve path smoothing and collaborative coverage of each partition.Two sets of simulation experiments are conducted.The first experiment verifies the effectiveness of the map preprocessing algorithm,and the second compares the proposed collaborative area coverage algorithm with other methods,demonstrating its performance advantages.展开更多
The World Journal of Gastroenterology Editorial Board Members are composed of 357 distinguished experts active in the relevant field,distributed in 46 countries/regions,including Italy(66),Japan(53),United States(31),...The World Journal of Gastroenterology Editorial Board Members are composed of 357 distinguished experts active in the relevant field,distributed in 46 countries/regions,including Italy(66),Japan(53),United States(31),China(29),South Korea(16),Spain(15),Australia(13),Greece(12),Brazil(11),Romania(8),Germany(7),India(7),Taiwan(7),United Kingdom(7),Türkiye(7),Hungary(5),Russia(5).展开更多
On December 8,1995,in accordance with historical conventions and religious rituals,and with the approval of the State Council of the People's Republic of China,the enthronement ceremony of Panchen Erdeni Chos-kyi ...On December 8,1995,in accordance with historical conventions and religious rituals,and with the approval of the State Council of the People's Republic of China,the enthronement ceremony of Panchen Erdeni Chos-kyi rGyal-po,the 11 th Panchen Erdeni,was solemnly held at the Tashilhunpo Monastery in Xigaze City,southwest China's Xizang Autonomous Region.This grand event successfully completed the major religious matter of the reincarnation of the late 10th Panchen Erdeni and fully embodied the policy on freedom of religious belief in China,earning the heartfelt support of monks and lay believers from all sectors of Xizang.展开更多
Groundwater modeling remains challenging due to heterogeneity and complexity of aquifer systems,necessitating endeavors to quantify Groundwater Levels(GWL)dynamics to inform policymakers and hydrogeologists.This study...Groundwater modeling remains challenging due to heterogeneity and complexity of aquifer systems,necessitating endeavors to quantify Groundwater Levels(GWL)dynamics to inform policymakers and hydrogeologists.This study introduces a novel Fuzzy Nonlinear Additive Regression(FNAR)model to predict monthly GWL in an unconfined aquifer in eastern Iran,using a 19-year(1998–2017)dataset from 11 piezometric wells.Under three distinct scenarios with progressively increasing input complexity,the study utilized readily available climate data,including Precipitation(Prc),Temperature(Tave),Relative Humidity(RH),and Evapotranspiration(ETo).The dataset was split into training(70%)and validation(30%)subsets.Results showed that among three input scenarios,Scenario 3(Sc3,incorporating all four variables)achieved the best predictive performance,with RMSE ranging from 0.305 m to 0.768 m,MAE from 0.203 m to 0.522 m,NSE from 0.661 to 0.980,and PBIAS from 0.771%to 0.981%,indicating low bias and high reliability.However,Sc2(excluding ETo)with RMSE ranging from 0.4226 m to 0.9909 m,MAE from 0.3418 m to 0.8173 m,NSE from 0.2831 to 0.9674,and PBIAS from−0.598%to 0.968%across different months offers practical advantages in data-scarce settings.The FNAR model outperforms conventional Fuzzy Least Squares Regression(FLSR)and holds promise for GWL forecasting in data-scarce regions where physical or numerical models are impractical.Future research should focus on integrating FNAR with deep learning algorithms and real-time data assimilation expanding applications across diverse hydrogeological settings.展开更多
The northeastern permafrost region of China is one of the most vulnerable areas to climate warming in midlatitude areas.Despite this,the specific pathways of water vapor circulation and transport in this area remain p...The northeastern permafrost region of China is one of the most vulnerable areas to climate warming in midlatitude areas.Despite this,the specific pathways of water vapor circulation and transport in this area remain poorly understood.Additionally,there is ongoing debate on whether the oxygen isotope of precipitation(δ^(18)O_(p))is primarily influenced by the temperature or the precipitation amount effects.Tree-ring samples were collected from various sites and tree species across the region,and 12 stable oxygen isotopes(δ18Oc)series constructed to investigate the water vapor signals embedded within.Our findings revealed consistentδ18Oc variations across different sites and species,reflecting relative humidity signals during the growing season(June to September)(r=−0.764,P<0.001,n=40).By applying an improved model to simulateδ^(18)O_(p),a“temperature effect”was identified.Bothδ18Oc andδ^(18)O_(p) provided valuable insights into the regional water vapor circulation,withδ18Oc offering a stronger climate signal.A binary linear regression model further revealed thatδ^(18)O_(p) had a greater influence onδ18Oc than relative humidity.The regional climate is primarily driven by the East Asian summer monsoon and large-scale water vapor circulation associated with the El Niño-Southern Oscillation.Because of future warming and drying trends,trees in this region are expected to face increasing drought stress.展开更多
In this paper,we define for the trace operator,the solution of certain models of vibrating plates standards with initial data in a strategic region spaces of weak regularities.Indeed,we know that the notion of regiona...In this paper,we define for the trace operator,the solution of certain models of vibrating plates standards with initial data in a strategic region spaces of weak regularities.Indeed,we know that the notion of regional controllability is more adapted to systems described by dynamic systems.Regional controllability results in a strategic area were established for vibrating plates by the Hilbertian Uniqueness Method.展开更多
Great Lakes Regions(GLRs)in China often confront landscape fragmentation,wetland degradation,and ecological resilience(ER)losses owing to extensive and intensive urbanization.In GLRs,however,the ER responses to urbani...Great Lakes Regions(GLRs)in China often confront landscape fragmentation,wetland degradation,and ecological resilience(ER)losses owing to extensive and intensive urbanization.In GLRs,however,the ER responses to urbanization remain unclear.This study explored the spatiotemporal evolution of ER and urbanization in five GLRs in China to analyze the ER dynamic patterns along center−lakeside−periphery gradient.The Spatial Durbin Model(SDM)and Panel Threshold Model(PTM)were combined to reveal the spillover and threshold effects of urbanization in five GLRs.The results indicate that the ER in five GLRs declined with a rate of 21%from 2000 to 2020.There was a clear“center-periphery”contraction trend with low ER areas primarily spreading to human activity-concentrated regions such as lakesides,riversides,and road networks.Driven by economic and land urbanization,the average urbanization level increased from 0.06 to 0.13,where lakesides,riversides,and road networks were key areas undergoing expansion.The urbanization showed a noticeable negative spatial spillover effect on ER.Away from central lakes,the negative impacts on ER exhibited a two-phase decrease with the threshold of 81 km.This study contributes to the understanding of human-environment interactions by examining the ecological resilience response process of GLRs under the impact of urbanization.Based on a multidimensional“center−lakeside−periphery”analytical model,this study provides a strategic framework for ecological construction in GLRs in China,promoting sustainable development and adaptive capacity in vulnerable areas.展开更多
This study explores theoretical insights and experimental results on monitoring load-carrying capacity degradation in bridge spans through frequency analysis.Experiments were conducted on real bridge structures,includ...This study explores theoretical insights and experimental results on monitoring load-carrying capacity degradation in bridge spans through frequency analysis.Experiments were conducted on real bridge structures,including the Binh Thuan Bridge,focusing on analyzing the power spectral density(PSD)of vibration signals under random traffic loads.Detailed digital models of various bridge spans with different structural designs and construction periods were developed to ensure diversity.The study utilized PSD to analyze the vibration signals from the bridge spans under various loading conditions,identifying the vibration frequencies and the corresponding response regions.The research correlated the observed frequency changes of PSD with the actual deterioration of the bridges over time,identifying patterns that indicate a reduction in stiffness.Experiments demonstrated that frequency changes,particularly in high-frequency regions,are directly related to a reduction in the stiffness of bridge spans.This supports the hypothesis that natural frequencies can serve as effective indicators of structural damage.Furthermore,the emergence and shift of resonant frequency regions provide valuable insights into the extent of damage in actual bridge spans,highlighting the potential for using changes in resonant frequency regions as a new tool for structural damage detection.展开更多
文摘Aims and scope GeoSus encourages wider analysis and innovative thinking about global and regional sustainability by bridging and synthesising natural and human sciences.GeoSus welcomes original,high-quality research articles,review articles,short communications,technical comments,perspective articles and editorials on the following themes.
基金Under the auspices of National Key Research and Development Program of China(No.2017YFA0604902,2024YFF1306802)Natural Science Foundation of Fujian Province(No.2022J01497)Open Project of the Strait Meteorology Laboratory(No.2025KF03)。
文摘China’s coastal regions,characterized by dense populations and industrial agglomeration,face escalating threats from typhoon disasters.Understanding the evolution of socio-economic exposure to future typhoon landfalls under global change is critical for effective disaster risk management.This study utilizes future typhoon track data simulated by the regional climate model version 4(RegCM4),combined with projected population and Gross Domestic Product(GDP)data for China’s coastal regions under three Shared Socioeconomic Pathways(SSPs:SSP1,sustainability;SSP2,middle of the road;SSP5,fossil-fueled development).We analyze typhoon impact zones for future periods(2030s,2050s,and 2090s)under Representative Concentration Pathways(RCPs:RCP2.6,RCP4.5,and RCP8.5,representing low,medium,and high greenhouse gas emission scenarios,respectively).Exposure levels for 2030,2050,and 2100 are calculated based on the annual average frequency of typhoon impacts during these periods,aiming to quantify the distribution characteristics of typhoon-affected population and GDP in China’s coastal regions.Key findings reveal two high-frequency typhoon im-pact zones:the Taiwan Strait region and the northern Qiongzhou Strait region.Furthermore,under RCP2.6,typhoon impacts may ex-tend to Liaoning,while RCP4.5 and RCP8.5 scenarios indicate potential impacts reaching further north to Heilongjiang.Under RCP4.5,Northeast China will experience the largest typhoon-affected area(43.800×10^(4) km^(2))by the 2030s.High population and GDP exposure concentrates in the Yangtze River Delta,the Pearl River Delta,and the Taiwan Strait coastal areas.Notably,Liaoning’s cumulative ex-posed population may exceed 0.100×10^(8) by 2030 and 2050 under RCP4.5 and RCP8.5 due to typhoon track migration.Given China’s location within the Western Pacific typhoon high-incidence region,the northward expansion of impacts will substantially escalate socio-economic exposure in mid-latitude regions previously at lower risk.These findings underscore the imperative for enhanced disaster pre-vention,mitigation strategies and targeted countermeasure research.
基金Supported by Provincial Key Research Project of Henan Province,No.232102310081.
文摘BACKGROUND Major depressive disorder(MDD)and obesity(OB)are bidirectionally comorbid conditions with common neurobiological underpinnings.However,the neurocognitive mechanisms of their comorbidity remain poorly understood.AIM To examine regional abnormalities in spontaneous brain activity among patients with MDD-OB comorbidity.METHODS This study adopted a regional homogeneity(ReHo)analysis of resting-state functional magnetic resonance imaging.The study included 149 hospital patients divided into four groups:Patients experiencing their first episode of drug-naive MDD with OB,patients with MDD without OB,and age-and sex-matched healthy individuals with and without OB.Whole-brain ReHo analysis was conducted using SPM12 software and RESTplus toolkits,with group comparisons via ANOVA and post-hoc tests.Correlations between ReHo values and behavioral measures were examined.RESULTS ANOVA revealed significant whole-brain ReHo differences among the four groups in four key regions:The left middle temporal gyrus(MTG.L),right cuneus,left precuneus,and left thalamus.Post-hoc analyses confirmed pairwise differences between all groups across these regions(P<0.05).OB was associated with ReHo alterations in the MTG.L,right cuneus,and left thalamus,whereas abnormalities in the precuneus suggested synergistic pathological mechanisms between MDD and OB.Statistically significant correlations were found between the drive and fun-seeking dimensions of the behavioral activation system,as well as behavioral inhibition and the corresponding ReHo values.CONCLUSION Our findings provide novel evidence for the neuroadaptive mechanisms underlying the MDD-OB comorbidity.Further validation could lead to personalized interventions targeting MTG.L hyperactivity and targeting healthy food cues.
文摘The metastatic pattern of colon cancer is typically well characterized,with initial dissemination occurring through regional lymphatics,followed by hematogenous spread.The most frequent sites of metastasis in colorectal cancer(CRC)include regional lymph nodes(50%–70%),liver(35%–50%),lungs(21%),peritoneum(15%),and ovaries(13%).1 Isolated distant lymph node metastasis,particularly in the absence of concurrent systemic disease,is exceedingly rare in CRC.To date,only six cases of isolated axillary lymph node metastasis(ALNM)from colorectal primaries have been documented in the literature.1–6 Even more uncommon is the incidental discovery of malignant cells in anastomotic doughnuts following stoma reversal procedures.Herein,we report a rare case involving both the incidental histopathological detection of tumor cells within doughnuts during stoma closure and the subsequent development of isolated ALNM after curative resection of sigmoid colon carcinoma.
基金supported,in part,by the National Nature Science Foundation of China under Grant 62272236,62376128 and 62306139the Natural Science Foundation of Jiangsu Province under Grant BK20201136,BK20191401.
文摘Discriminative region localization and efficient feature encoding are crucial for fine-grained object recognition.However,existing data augmentation methods struggle to accurately locate discriminative regions in complex backgrounds,small target objects,and limited training data,leading to poor recognition.Fine-grained images exhibit“small inter-class differences,”and while second-order feature encoding enhances discrimination,it often requires dual Convolutional Neural Networks(CNN),increasing training time and complexity.This study proposes a model integrating discriminative region localization and efficient second-order feature encoding.By ranking feature map channels via a fully connected layer,it selects high-importance channels to generate an enhanced map,accurately locating discriminative regions.Cropping and erasing augmentations further refine recognition.To improve efficiency,a novel second-order feature encoding module generates an attention map from the fourth convolutional group of Residual Network 50 layers(ResNet-50)and multiplies it with features from the fifth group,producing second-order features while reducing dimensionality and training time.Experiments on Caltech-University of California,San Diego Birds-200-2011(CUB-200-2011),Stanford Car,and Fine-Grained Visual Classification of Aircraft(FGVC Aircraft)datasets show state-of-the-art accuracy of 88.9%,94.7%,and 93.3%,respectively.
基金supported by the National Natural Science Foundation of China(Nos.52071057,52171247)the Liaoning Youth Elite Talent Program(No.XLYC220309)。
文摘Waves are important physical phenomena in an ocean,and their accurate prediction is essential for ocean engineering,maritime traffic,and marine early warning systems.This study focuses on the Qinhuangdao Sea area located in the Bohai Sea,China.Herein,we use on-site wind data to correct the reanalysis wind data obtained from the European Centre for Medium-Range Weather Forecasts(ECMWF),improving the accuracy of boundary conditions.Then,we use the Simulating WAves Nearshore(SWAN)model to simulate the regional wave field over time.A regional wave-parameter prediction model is then developed using a limited number of sampled data(covering only 2 years,2020–2021);the model is based on the Whale Optimization Algorithm(WOA),convolutional neural networks(CNNs),and long short-term memory(LSTM)neural networks.WOA is used to optimize the CNN and LSTM framework;in this framework,CNN extracts spatial features,and the LSTM network captures temporal features,enabling accurate short and long-term predictions of wave height,period,and direction.The experimental results showed that despite the small sample size,the model achieves a goodness of fit of 0.9957 for wave height prediction,0.9973 for period,and 0.9749 for wave direction in short-term forecasting.As the prediction step size increases,the accuracy of the model decreases.When the prediction step size reaches 9 h,the root mean square error for the prediction of wave height,period,and direction increases to 0.2060 m,0.4582 s,and32.5358°,respectively.The reliability and applicability of the model are further validated by the experimental results.Our findings highlighted the potential of the developed model in operational wave forecasting,even with a limited number of sampled data.
基金supported by the National Key R&D Program of China(Grant No.2022YFC3003701)the National Natural Science Foundation of China(Grant No.42488301)the Xinjiang Uygur Autonomous Region Key R&D Project(Grant No.2022B03001-1).
文摘The Xinjiang region is situated between the Tethyan and Central Asian orogenic belts.It has undergone multiple episodes of accretionary orogenesis and was tectonically reactivated during the Cenozoic by the far-field compressional effects of the India-Eurasia continental collision.These processes have generated pronounced seismicity and recurrent earthquake-related hazards in this region.A high-resolution three-dimensional velocity model is essential for multi-scale velocity model construction,source-parameter inversion,simulation of strong ground motion,and seismic hazard assessment.In this study,we collected first-arrival body-wave travel-time data recorded by permanent stations in and around Xinjiang and processed both ambient-noise and regional-earthquake surface-wave records.The resulting dataset comprises~8.1 million body-wave travel-time picks-including absolute arrival times and event-pair differential times-and~5,000 surface-wave dispersion curves(5-50 s period).By joint inversion of these complementary body and surface wave datasets,we determined a high-resolution three-dimensional V_(p) and V_(s) model for the crust and uppermost mantle beneath Xinjiang(XJVM-1.0)with a lateral resolution of 50-100 km and a vertical resolution of~10 km.XJVM-1.0 reveals that the Tianshan orogen exhibits a relatively rigid upper crust that hosts abundant seismicity under far-field compression,whereas its middle-lower crust accommodates the majority of compressional stress through plastic deformation and/or partial melting.In contrast,the interiors of the Junggar and Tarim basins have experienced negligible internal deformation and are inferred to underthrust beneath the Tianshan orogen in response to the India-Eurasia collision.Relocated seismicity indicates that earthquakes are predominantly concentrated within the Tianshan range,with a notable proportion occurring in the middle-lower crust,implying whole-crust tectonic activity and highlighting the potential for great earthquakes in this region.
文摘The editors of International Journal of Ophthalmology gratefully acknowledge the members of IJO Editorial Board and reviewers from 51 countries and regions who participated in the peer-reviews and provided their valuable comments between Nov.1st,2024 and Oct.31st,2025.They volunteer their valuable time and expertise,and without them we would not maintain the necessary quality expected of the journal.We apologize if we have inadvertently missed a reviewer’s name off this list.
文摘Contemporary Social Sciences publishes outstanding research in the field of social sciences in China and also includes high-quality research work by foreign scholars on the development of China’s western regions and its reform and opening up.The aim is to help promote China’s academic achievements to the world and give China a stronger voice in the global community of social sciences.The scopes of research fields for consideration include,but not limited to political science,economics,literature,linguistics,journalism and communication,education,sociology,philosophy,history,law,and interdisciplinary research.
基金supported by the National Natural Science Foundation of China(grant no.32371866)。
文摘Drought influences carbon fixation by plants.Therefore,elucidating its impact on carbon fluxes in plants at the ecosystem level is crucial for assessing their role in mitigating climate change.Using carbon fluxes and environmental factor data from FLUXNET sites,we analyzed the influence of drought on carbon fluxes,their drivers,time-lag effects,and recovery times across various climatic regions and seasons.Results showed drought significantly decreased gross primary production(GPP),ecosystem respiration,and net ecosystem productivity in arid regions but slightly increased carbon sequestration in humid regions.Summer droughts negatively affected vegetation carbon fluxes,partly offset by the positive impact of spring droughts.Nonforest carbon fluxes were more susceptible to drought effects than forest fluxes.Soil water content(SWC)was the main influence on changes in arid regions,whereas vapor pressure deficit(VPD)dominated humid regions.Decreased SWC and increased VPD reduced carbon sequestration in arid regions but increased it in humid regions.Increased VPD reduced GPP,leading to forest carbon loss,whereas decreased SWC reduced GPP,leading to nonforest carbon loss.The lag time of the drought effects on carbon fluxes was longer in humid regions(19.44 d)than in arid regions(14.71 d).Compared to nonforest areas(16.74 d and 57 d for drought lag and recovery time,respectively),forest areas had a longer lag(18.81 d)and recovery time(92 d).The findings revealed discrepancies in the main factors regulating vegetation carbon fluxes during droughts between arid and humid regions and between forest and nonforest ecosystems.These insights provide a new perspective on understanding and simulating carbon-climate feedback.Enhancing ecosystem diversity is a feasible measure to increase drought resistance.
基金supported by the“Regional Innovation System&Education(RISE)”through the Seoul RISE Center,funded by the Ministry of Education(MOE)and the Seoul Metropolitan Government.(2025-RISE-01-005-07).
文摘Background:Social connection is widely recognized as a protective determinant of health,yet its direct and indirect effects on mental health remain underexplored.This study examines the relationship between social connection and mental health,focusing on the mediating role of quality of life(QoL)and the moderating effect of regional differences.Methods:We analyzed data from the 2019 Korean Community Health Survey,comprising 229,099 adults.Mental health was assessed through validated measures of depressive symptoms and psychological well-being.Social connection was measured using indicators of interpersonal ties and community participation,and QoL was assessed via self-reported health-related satisfaction across major life domains.Analytical procedures included mediation modeling and subgroup analyses by region,with significance levels set at p<0.05.Results:The results indicate that social connections are significantly associated with lower stress levels and reduced depressive symptoms,with QoL playing a critical mediating role.Notably,the indirect effect of social connection on mental health via QoL is stronger in rural areas compared to urban regions,highlighting the importance of social cohesion and community support in mental well-being.Among 203,567 adults,greater social participation was associated with lower subjective stress(total effect=−0.052,p<0.001)and fewer depressive symptoms(PHQ-9 total effect=−0.308,p<0.001).QoL significantly mediated these associations,with the strongest indirect pathways observed through usual activities(19.2%for stress;27.6%for depression)and mobility(24.4%for depression).Regional analysis showed stronger mediation in rural areas(up to 26.8%for stress and 32.6%for depression)than in urban areas(8–16%and 14.9–23%).Direct effects remained significant,indicating partial mediation.These findings highlight that social participation enhances mental health directly and indirectly through QoL,particularly in rural contexts.Conclusions:Social connection contributes to better mental health both directly and indirectly through improved QoL,with stronger effects observed in rural communities.These findings highlight the importance of fostering social cohesion and enhancing life quality as strategies for improving population mental health.Policy interventions should adopt context-sensitive approaches that account for regional differences in social resources and service availability.
基金Supported by National Natural Science Foundation of China(No.42172212).
文摘The Jiao-Liao-Ji Belt within the North China Craton had undergone a complex tectonic evolution,marked by extensive Paleoproterozoic magmatism that produced a diverse range of mafic to felsic magmatic rocks.These events provide valuable geological records for understanding the tectonic evolution of the Jiao-Liao-Ji Belt.This study focuses on the Paleoproterozoic Chibaisong meta-gabbro in southern Jilin,investigating the source of mafic magma,petrogenesis,and tectonic setting through systematic petrological analysis,zircon U-Pb dating,and geochemical studies.The findings contribute to constraining the dynamic mechanisms of Paleoproterozoic extensional rifting in the Jiao-Liao-Ji orogenic belt.Geochemical data indicate that the samples exhibit low SiO₂(47.99–50.66 wt.%),TiO₂(0.75–3.20 wt.%),Nb(3.22–8.09 ppm),and Ta(0.22–0.51 ppm)contents,along with high TFeO₃(11.97–15.82 wt.%)and MgO(5.67–12.66 wt.%)concentrations.They also show low Nb/La ratios and high(Th/Nb)N values,consistent with the geochemical characteristics of tholeiitic basalts.The samples display low total rare earth element concentrations,weak or absent Eu anomalies,slight enrichment in light rare earth elements,relatively flat heavy rare earth element patterns,and depletion in Nb,Ta,and Ti.The meta-gabbro from southern Jilin exhibits geochemical similarities to Paleoproterozoic metamafic rocks from other regions of the Jiao-Liao-Ji Belt,resembling enriched mid-ocean ridge basalts(E-MORB)with Nb,Ta,and Ti depletion.Integration of previous studies and geochemical data suggests that the 2.16–2.10 Ga metamafic rocks in the Jiao-Liao-Ji Belt experienced contamination by older crustal material.These results indicate that the 2.16–2.10 Ga metamafic rocks are unlikely to be associated with island arc,continental arc,or mid-ocean ridge settings.Instead,they are more likely related to intraplate magmatism associated with continental rifting.
基金National Natural Science Foundation of China(62402020,62303022)Beijing Nova Program(20240484720)+1 种基金Project of Cultivation for Young Top-Notch Talents of Beijing Municipal Institutions(BPHR202203043)BTBU Digital Business Platform Project byBMEC.
文摘Unmanned aerial vehicles(UAVs)are widely utilized in area coverage tasks due to their flexibility and efficiency in geo-graphic information acquisition.However,complex boundary conditions in actual water area maps often reduce coverage efficiency.To address this issue,this paper proposes a map preprocessing algorithm that linearizes boundary lines and processes concave areas into concave polygons,followed by gridding the map.Additionally,a collaborative area coverage method for UAV swarms is introduced based on region partitioning,which considers the comprehensive cost of energy consumption and time.An improved Hungarian algorithm is utilized for region partitioning,and a Dubins-A*-based plow-ing area full coverage path planning method is proposed to achieve path smoothing and collaborative coverage of each partition.Two sets of simulation experiments are conducted.The first experiment verifies the effectiveness of the map preprocessing algorithm,and the second compares the proposed collaborative area coverage algorithm with other methods,demonstrating its performance advantages.
文摘The World Journal of Gastroenterology Editorial Board Members are composed of 357 distinguished experts active in the relevant field,distributed in 46 countries/regions,including Italy(66),Japan(53),United States(31),China(29),South Korea(16),Spain(15),Australia(13),Greece(12),Brazil(11),Romania(8),Germany(7),India(7),Taiwan(7),United Kingdom(7),Türkiye(7),Hungary(5),Russia(5).
文摘On December 8,1995,in accordance with historical conventions and religious rituals,and with the approval of the State Council of the People's Republic of China,the enthronement ceremony of Panchen Erdeni Chos-kyi rGyal-po,the 11 th Panchen Erdeni,was solemnly held at the Tashilhunpo Monastery in Xigaze City,southwest China's Xizang Autonomous Region.This grand event successfully completed the major religious matter of the reincarnation of the late 10th Panchen Erdeni and fully embodied the policy on freedom of religious belief in China,earning the heartfelt support of monks and lay believers from all sectors of Xizang.
基金supported by the Iran National Science Foundation(INSF)the University of Birjand under grant number 4034771.
文摘Groundwater modeling remains challenging due to heterogeneity and complexity of aquifer systems,necessitating endeavors to quantify Groundwater Levels(GWL)dynamics to inform policymakers and hydrogeologists.This study introduces a novel Fuzzy Nonlinear Additive Regression(FNAR)model to predict monthly GWL in an unconfined aquifer in eastern Iran,using a 19-year(1998–2017)dataset from 11 piezometric wells.Under three distinct scenarios with progressively increasing input complexity,the study utilized readily available climate data,including Precipitation(Prc),Temperature(Tave),Relative Humidity(RH),and Evapotranspiration(ETo).The dataset was split into training(70%)and validation(30%)subsets.Results showed that among three input scenarios,Scenario 3(Sc3,incorporating all four variables)achieved the best predictive performance,with RMSE ranging from 0.305 m to 0.768 m,MAE from 0.203 m to 0.522 m,NSE from 0.661 to 0.980,and PBIAS from 0.771%to 0.981%,indicating low bias and high reliability.However,Sc2(excluding ETo)with RMSE ranging from 0.4226 m to 0.9909 m,MAE from 0.3418 m to 0.8173 m,NSE from 0.2831 to 0.9674,and PBIAS from−0.598%to 0.968%across different months offers practical advantages in data-scarce settings.The FNAR model outperforms conventional Fuzzy Least Squares Regression(FLSR)and holds promise for GWL forecasting in data-scarce regions where physical or numerical models are impractical.Future research should focus on integrating FNAR with deep learning algorithms and real-time data assimilation expanding applications across diverse hydrogeological settings.
基金supported by the National Natural Science Foundation of China(Grant Nos.42173080 and 42488201)the Chinese Academy of Sciences(Grant No.XDB40010300)the Young Talent Support Plan of Xi’an Jiaotong University.
文摘The northeastern permafrost region of China is one of the most vulnerable areas to climate warming in midlatitude areas.Despite this,the specific pathways of water vapor circulation and transport in this area remain poorly understood.Additionally,there is ongoing debate on whether the oxygen isotope of precipitation(δ^(18)O_(p))is primarily influenced by the temperature or the precipitation amount effects.Tree-ring samples were collected from various sites and tree species across the region,and 12 stable oxygen isotopes(δ18Oc)series constructed to investigate the water vapor signals embedded within.Our findings revealed consistentδ18Oc variations across different sites and species,reflecting relative humidity signals during the growing season(June to September)(r=−0.764,P<0.001,n=40).By applying an improved model to simulateδ^(18)O_(p),a“temperature effect”was identified.Bothδ18Oc andδ^(18)O_(p) provided valuable insights into the regional water vapor circulation,withδ18Oc offering a stronger climate signal.A binary linear regression model further revealed thatδ^(18)O_(p) had a greater influence onδ18Oc than relative humidity.The regional climate is primarily driven by the East Asian summer monsoon and large-scale water vapor circulation associated with the El Niño-Southern Oscillation.Because of future warming and drying trends,trees in this region are expected to face increasing drought stress.
文摘In this paper,we define for the trace operator,the solution of certain models of vibrating plates standards with initial data in a strategic region spaces of weak regularities.Indeed,we know that the notion of regional controllability is more adapted to systems described by dynamic systems.Regional controllability results in a strategic area were established for vibrating plates by the Hilbertian Uniqueness Method.
基金supported by the National Natural Science Foundation of China(Grants No.42301226,42271209 and 42471199)the Fundamental Research Funds for the Central Universities(Grant No.2024CDJXY014)+2 种基金the Natural Science Foundation of Jiangxi Province(Grant No.20242BAB25170)Special Funds for Water Resources in Jiangxi Province(Science and Technology Projects)(Grant No.202425YBKT16)the Young Talent Cultivation and Innovation Fund Project of Nanchang University(Grant No.XX202506030028).
文摘Great Lakes Regions(GLRs)in China often confront landscape fragmentation,wetland degradation,and ecological resilience(ER)losses owing to extensive and intensive urbanization.In GLRs,however,the ER responses to urbanization remain unclear.This study explored the spatiotemporal evolution of ER and urbanization in five GLRs in China to analyze the ER dynamic patterns along center−lakeside−periphery gradient.The Spatial Durbin Model(SDM)and Panel Threshold Model(PTM)were combined to reveal the spillover and threshold effects of urbanization in five GLRs.The results indicate that the ER in five GLRs declined with a rate of 21%from 2000 to 2020.There was a clear“center-periphery”contraction trend with low ER areas primarily spreading to human activity-concentrated regions such as lakesides,riversides,and road networks.Driven by economic and land urbanization,the average urbanization level increased from 0.06 to 0.13,where lakesides,riversides,and road networks were key areas undergoing expansion.The urbanization showed a noticeable negative spatial spillover effect on ER.Away from central lakes,the negative impacts on ER exhibited a two-phase decrease with the threshold of 81 km.This study contributes to the understanding of human-environment interactions by examining the ecological resilience response process of GLRs under the impact of urbanization.Based on a multidimensional“center−lakeside−periphery”analytical model,this study provides a strategic framework for ecological construction in GLRs in China,promoting sustainable development and adaptive capacity in vulnerable areas.
文摘This study explores theoretical insights and experimental results on monitoring load-carrying capacity degradation in bridge spans through frequency analysis.Experiments were conducted on real bridge structures,including the Binh Thuan Bridge,focusing on analyzing the power spectral density(PSD)of vibration signals under random traffic loads.Detailed digital models of various bridge spans with different structural designs and construction periods were developed to ensure diversity.The study utilized PSD to analyze the vibration signals from the bridge spans under various loading conditions,identifying the vibration frequencies and the corresponding response regions.The research correlated the observed frequency changes of PSD with the actual deterioration of the bridges over time,identifying patterns that indicate a reduction in stiffness.Experiments demonstrated that frequency changes,particularly in high-frequency regions,are directly related to a reduction in the stiffness of bridge spans.This supports the hypothesis that natural frequencies can serve as effective indicators of structural damage.Furthermore,the emergence and shift of resonant frequency regions provide valuable insights into the extent of damage in actual bridge spans,highlighting the potential for using changes in resonant frequency regions as a new tool for structural damage detection.
