Light serves as the source of energy as well as an information signal for photosynthetic plants. During evolution, plants have acquired the ability to monitor environmental light radiation and adjust their development...Light serves as the source of energy as well as an information signal for photosynthetic plants. During evolution, plants have acquired the ability to monitor environmental light radiation and adjust their developmental patterns to optimally utilize light energy for photosynthesis. The mechanisms of light perception and signal transduction have been comprehensively studied in past decades, mostly in a few model plants, including Arabidopsis thaliana. However, systematic analyses of the origin and evolution of core components involved in light perception and signaling are still lacking. In this study, we took advantage of the recently sequenced genomes and transcriptomes covering all the main Archaeplastida clades in the public domain to identify orthologous genes of core components involved in light perception and signaling and to reconstruct their evolutionary history. Our analyses suggested that acclimation to different distribution of light quality in new environments led to the origination of specific light signaling pathways in plants. The UVR8 (UV Resistance Locus 8) signaling pathway originated during the movement of plants from the deeper sea to shallow water and enabled plants to deal with ultraviolet B light (UV-B). After acquisition of UV-B adaptation, origination of the phytochrome signaling pathway helped plants to colonize water surface where red light became the prominent light energy source. The seedling emergence pathway, which is mediated by a combination of light and phytohormone signals that orchestrate plant growth pattern transitions, originated before the emergence of seed plants. Although cryptochromes and some key components of E3 ubiquitin ligase systems already existed before the divergence of the plant and animal kingdoms, the coevolution and optimization of light perception and downstream signal transduction components, including key transcription factors and E3 ubiquitin ligase systems, are evident during plant terrestrialization.展开更多
Climate change and anthropogenic activities have driven significant terrestrial water storage changes(TWSC)in the Three Rivers Source Region(TRSR),exerting profound impacts on freshwater availability across China and ...Climate change and anthropogenic activities have driven significant terrestrial water storage changes(TWSC)in the Three Rivers Source Region(TRSR),exerting profound impacts on freshwater availability across China and broader Asia.However,long-term TWSC characterization remains challenging due to limited observational data in this alpine region.Here,we integrate GRACE observations(2002-2020),ERA5-Land reanalysis,and GLDAS data to reconstruct TWSC using two methods:(1)the water balance method(PER)and(2)the component summation method(SS),applied to three input datasets(ERA5-Land,GLDAS,and their average,GLER).Comparative analysis reveals that the SS method applied to GL-ER yields the highest consistency with GRACE-derived TWSC.Using this optimal approach,we extend the analysis to 1951~2020,uncovering spatiotemporal TWSC patterns.Although annual TWSC trends appear negligible due to strong seasonality,we introduce the intra-year TWSC fluctuation(TWSCF)index to quantify cumulative variability.A significant(p<0.05)transition occurred in 1980,with TWSCF shifting from a declining trend(-0.39 mm/yr)to an increasing trend(0.56 mm/yr),primarily driven by soil moisture changes.However,Hurst exponent analysis suggests this upward trend may not persist.Drought and vegetation assessments indicate concurrent wetting and greening in the TRSR.TWSC correlates strongly with meteorological drought,acting as a reliable drought indicator while its linkage with vegetation dynamics suggests a potential contribution to greening.Our findings provide a robust framework for understanding long-term TWSC evolution and its hydrological-ecological interactions under climate change.展开更多
Clarifying the mechanisms through which coal mining affects groundwater storage(GWS)variations is crucial for water resource conservation and sustainable development.The Ordos Mining Region in China,a key energy base ...Clarifying the mechanisms through which coal mining affects groundwater storage(GWS)variations is crucial for water resource conservation and sustainable development.The Ordos Mining Region in China,a key energy base in China with significant strategic importance,has undergone intensive coal mining activities that have substantially disrupted regional groundwater circulation.This study integrated data from the Gravity Recovery and Climate Experiment Satellite(GRACE)and Famine Early Warning Systems Network(FEWS NET)Land Data Assimilation System(FLDAS)models,combined with weighted downscaling methodology and water balance principles,to reconstruct high-resolution(0.01°)terrestrial water storage(TWS)and GWS changes in the Ordos Mining Region,China from April 2002 to December 2021.The accuracy of GWS variations were validated through pumping test measurements.Subsequently,Geodetector analysis was implemented to quantify the contributions of natural and anthropogenic factors to groundwater storage dynamics.Key findings include:1)TWS in the study area showed a fluctuating but overall decreasing trend,with a total reduction of 8901.11 mm during study period.The most significant annual decrease occurred in 2021,reaching 1696.77 mm.2)GWS exhibited an accelerated decline,with an average annual change rate of 44.35 mm/yr,totaling a decrease of 887.05 mm.The lowest annual groundwater storage level was recorded in 2020,reaching 185.69 mm.3)Precipitation(PRE)contributed the most to GWS variation(q=0.52),followed by coal mining water consumption(MWS)(q=0.41).The interaction between PRE and MWS exhibited a nonlinear enhancement effect on GWS changes(0.54).The synergistic effect of natural hydrological factors has a great influence on the change of GWS,but coal mining water consumption will continue to reduce GWS.These findings provide critical references for the management and regulation of groundwater resource in mining regions.展开更多
Space-Terrestrial Integrated 6G Network:Architecture,Networking,and Transmission Technologies With the large-scale deployment of satellite constellations such as Starlink and the rapid advancement of technologies incl...Space-Terrestrial Integrated 6G Network:Architecture,Networking,and Transmission Technologies With the large-scale deployment of satellite constellations such as Starlink and the rapid advancement of technologies including artificial intelligence(AI)and non-terrestrial networks(NTNs),the integration of high,medium,and low Earth orbit satellite networks with terrestrial networks has become a critical direction for future communication technologies.展开更多
With the large-scale deployment of satellite constellations such as Starlink and the rapid advancement of technologies including artificial intelligence (AI) and non-terrestrial networks (NTNs), the integration of hig...With the large-scale deployment of satellite constellations such as Starlink and the rapid advancement of technologies including artificial intelligence (AI) and non-terrestrial networks (NTNs), the integration of high, medium, and low Earth orbit satellite networks with terrestrial networks has become a critical direction for future communication technologies. The objective is to develop a space-terrestrial integrated 6G network that ensures ubiquitous connectivity and seamless services, facilitating intelligent interconnection and collaborative symbiosis among humans, machines, and objects. This integration has become a central focus of global technological innovation.展开更多
Oil tanks are essential components of the oil industry, facilitating the safe storage and transportation of crude oil. Safely managing oil tanks is a crucial aspect of environmental protection. Oil tanks are often use...Oil tanks are essential components of the oil industry, facilitating the safe storage and transportation of crude oil. Safely managing oil tanks is a crucial aspect of environmental protection. Oil tanks are often used under extreme operational conditions, including dynamic loads, temperature variations, etc., which may result in unpredictable deformations that can cause severe damage or tank collapses. Therefore, it is essential to establish a monitoring system to prevent and predict potential deformations. Terrestrial laser scanning (TLS) has played a significant role in oil tank monitoring over the past decades. However, the full extent of TLS capabilities for oil tank monitoring has not yet been thoroughly investigated. This study aims to evaluate TLS’s abilities in detecting deformations of oil tanks under various operating conditions. The paper has two objectives: first, to examine the deformations of two vertical oil tanks over six years, and second, to investigate potential deformations of the tanks’ surfaces during filling. Each tank was scanned three times—in the years 2015, 2016, and 2021. Mathematical models and appropriate software were developed to determine the achievable accuracy of TLS monitoring. The anticipated monitoring accuracy was simulated based on the design parameters of the oil tanks. This accuracy was subsequently used to differentiate between deformations and measurement errors. The tank surface was approximated utilizing the cylinder equation for each monitoring epoch. Additionally, deformations were analyzed at different cross-sections with the appropriate circular approximations. The results indicated that both tanks exhibited no significant deformations within a range of less than 20 mm. For the empty tanks, the average radius decreased by 4 mm, without any changes in shape. The total spatial inclination of the oil tanks was calculated using cylinder equations at different monitoring epochs. In the final stage, the observed deformations were employed to simulate the strain-stress conditions of the oil tanks. Thus, this paper presents a complex technology and the results of oil tank monitoring by TLS under various operating conditions.展开更多
Exoplanet imaging using the solar gravitational lens is an enticing prospect.The fundamental physical properties of the lens,including its angular resolution and light amplification,promise exceptional capabilities.Th...Exoplanet imaging using the solar gravitational lens is an enticing prospect.The fundamental physical properties of the lens,including its angular resolution and light amplification,promise exceptional capabilities.These expectations,however,are tempered by the realization of numerous challenges,including imperfections of the lens itself,noise sources,the properties of the imaging target and difficult technical issues.We discuss,in particular,a subject not previously addressed,the impact of temporally varying surface features,notably a variable cloud cover,obscuring the target exoplanet.This has a substantial detrimental effect on image recovery,leading to our cautious assessment of the practical feasibility of using the Sun’s gravitational field as an effective telescope.展开更多
In the context of global warming, the increasing wildfire frequency has become a critical climate research focus in North America. This study used the Community Earth System Model(CESM 1.2) to investigate the impacts ...In the context of global warming, the increasing wildfire frequency has become a critical climate research focus in North America. This study used the Community Earth System Model(CESM 1.2) to investigate the impacts of 20thcentury wildfires on North American climate and hydrology. Summer represents the peak wildfire season in North America, with the Gulf of Mexico and Midwest regions experiencing the most severe effects. Wildfires not only damage vegetation during the fire season but also extend prolonged impacts into non-fire periods, showing distinct seasonal variations. In spring, wildfires increase surface albedo, triggering a cooling effect through enhanced snow cover and delayed snowmelt. Conversely, summer and autumn surface warming stems primarily from wildfire-suppressed vegetation transpiration. Warming near the Gulf of Mexico enhances moisture transport and precipitation, particularly in summer and autumn. Reduced evaporation and increased precipitation from the Gulf of Mexico significantly altered the hydrological cycle across North America, leading to increased runoff continent-wide.展开更多
Areca nut is the basic ingredient of betel quid,which is chewed by hundreds of millions of people in South-Eastern Asia.Chewing of areca nut has been associated with oral cancers potentially due to its specific alkalo...Areca nut is the basic ingredient of betel quid,which is chewed by hundreds of millions of people in South-Eastern Asia.Chewing of areca nut has been associated with oral cancers potentially due to its specific alkaloids,among which arecoline constitutes about 90%of total fraction.Being the world’s fourth most commonly used psychoactive substance,arecoline evokes stimulation,addiction,and other direct neurological effects,while its misuse correlates to neurotoxic effects.However,what might underlie its neurotoxic mechanisms has been poorly documented.The brain is encoded by a complex network of neuronal and glial cell types,and neurotoxicity of hazardous compounds present transcriptional heterogeneity.Recently,the eusocial bumblebee has been used as a model for studying brain effects,with sophisticated cognitive capability and precisely measured brain architecture.Here,we decipher cell-type-specific mental risks to arecoline using bumblebees.Arecoline induced locomotor hyperactivity and cognitive impairment.Single nucleus RNA sequencing(snRNA-seq)unearthed arecoline-induced cell-specific responses,primarily targeted on Kenyon cells(KC).Moreover,high-dose arecoline induced distinctive cell responses among KC subtypes,particularly class I large Kenyon cell(lKC),leading to DNA damage,excitatory/inhibitory(E/I)imbalance,and calcium dyshomeostasis,which potentially resulted in cognitive impairment.Given arecoline’s popularity and growing exposure risks to humans,neurological health risks of areca nut warrant serious consideration.展开更多
Branch angles are an important plant morphological trait affecting light interception within forest canopies.However,studies on branch angles have been limited due to the time-consuming nature of manual measurements u...Branch angles are an important plant morphological trait affecting light interception within forest canopies.However,studies on branch angles have been limited due to the time-consuming nature of manual measurements using a protractor.Terrestrial laser scanning(TLS),however,provides new opportunities to measure branch angles more efficiently.Despite this potential,studies validating branch angle measurements from TLS have been limited.Here,our aim is to evaluate both manual and automatic branch angle measurements of European beech from TLS data using traditional field-measurements with a protractor as a reference.We evaluated the accuracy of branch angle measurements based on four automated algorithms(aRchiQSM,TreeQSM,Laplacian,SemanticLaplacian)from TLS data.Additionally,we assessed different ways of manual branch angle measurements in the field.Our study was based on a dataset comprising 124 branch angles measured from six European beech in a European deciduous forest.Our results show that manual branch angle measurements from TLS data are in high agreement with the reference(root-mean-squared error,RMSE:[3.57°-4.18°],concordance correlation coefficient,CCC:[0.950.97])across different branch length positions.Automated algorithms also are in high agreement with the reference although RMSE is approximately twice as large compared to manual branch angle measurements from TLS(RMSE:[9.29°-10.55°],CCC:[0.830.86])with manual leaf points removal.When applying the automatic wood-leaf separation algorithm,the performance of the four methods declined significantly,with only approximately 20 branch angles successfully identified.Moreover,it is important to note that there is no influence of the measurement position(branch surface versus center)for branch angle measurements.However,for curved branches,the selection of branch measurement length significantly impacts the branch angle measurement.This study provides a comprehensive understanding of branch angle measurements in forests.We show that automated measurement methods based on TLS data of branch angles are a valuable tool to quantify branch angles at larger scales.展开更多
To explore the factors controlling human activity in Northeast Asia during the last deglaciation,this study synthesizes six pollen records from lakes and peatlands,alongside four paleotemperature records from terrestr...To explore the factors controlling human activity in Northeast Asia during the last deglaciation,this study synthesizes six pollen records from lakes and peatlands,alongside four paleotemperature records from terrestrial sedimentary sequences in this region.We simulated potential hunter-gatherer population densities using the Minimalist Terrestrial Resource Model(MTRM),and calculated vegetation openness,rate of change,and evenness based on pollen data.The results reveal a direct relationship between plant resources and hunter-gatherer populations from 20.9 to 10.2 ka BP.The synchronous increases in plant resources and population density from the Last Glacial(LG)to the B?lling-Aller?d(BA)warm period,as well as from the Younger Dryas(YD)to the early Holocene(EH),with stasis during the YD,suggest that resource availability was a key driver of human activity.Redundancy analysis(RDA)of pollen and paleotemperature records indicated that vegetation and plant resources were more closely linked to the mean annual air temperature,with winter characteristics,from the LG to the YD,whereas warm-season temperatures played a more significant role during the EH.This research emphasizes that variations in resource accessibility,rather than direct climate effects alone,were likely pivotal in shaping human activity responses to environmental changes.展开更多
The rhenium-osmium(Re-Os)isotope system is a powerful tool for dating organic-rich sedimentary rocks,yet the mechanisms of Re and Os uptake and their fractionation in different types of organic matter remain poorly un...The rhenium-osmium(Re-Os)isotope system is a powerful tool for dating organic-rich sedimentary rocks,yet the mechanisms of Re and Os uptake and their fractionation in different types of organic matter remain poorly understood.Here,we investigate the role of terrestrial organic matter(e.g.,wood of the species Taxodium distichum and charcoal generated from the same species in the laboratory)in Re and Os enrichment and isotope fractionation through laboratory experiments.The results show that charcoal has a significantly higher capacity to uptake both Re(68-77 times greater)and Os(1.7-2.2 times higher)compared to wood,with charcoal preferentially accumulating Re over Os,leading to higher^(187)Re/^(188)Os ratios.These findings highlight the important contribution of terrestrial organic matter,particularly charcoal,to Re and Os concentrations and isotope fractionation in shales,and the importance of organic matter type for chelating Re and Os as previously discussed.Furthermore,we discuss the potential of using Re to track organic carbon weathering,noting that the coupled release of Re and organic carbon during weathering provides new insights into carbon cycling processes.展开更多
In this study,terrestrial laser scanning(TLS)is used to collect building data after the M_(s) 7.0 magnitude earthquake in Lushan,Sichuan,China in 2013 for analysis and research.The analysis focuses on extracting the t...In this study,terrestrial laser scanning(TLS)is used to collect building data after the M_(s) 7.0 magnitude earthquake in Lushan,Sichuan,China in 2013 for analysis and research.The analysis focuses on extracting the tilt and deformation of masonry buildings that are difficult to identify through visual inspection in basically intact,slightly damaged and moderately damaged masonry buildings,to solve the problem of ambiguous identification of damage.A quantitative analysis of the determination indexes of the degree of earthquake damage was carried out,and the numerical characteristics parameters such as the curvature of the wall point cloud proximity,angle,contour of the fitted plane of the point cloud,verticality(flatness)of the wall,standard deviation of the profile and angle of the profile were established to determine the degree of earthquake damage to buildings based on LiDAR data.The development of quantitative determination indexes for the degree of earthquake damage of buildings in this study has important application value for LiDAR data in the identification and extraction of earthquake damage information and damage level determination.展开更多
The present study was conducted to examine the trophic transfer of potentially toxic elements(PTEs)in a closed arsenic mine.Eight PTEs in a soil-plant-leaf litter-earthworm-top predators(free-range local chicken and w...The present study was conducted to examine the trophic transfer of potentially toxic elements(PTEs)in a closed arsenic mine.Eight PTEs in a soil-plant-leaf litter-earthworm-top predators(free-range local chicken and wild passerine bird)system were analyzed for nitrogen and carbon stable isotopes,PTE concentrations,bioaccumulation factors(BAFs),and transfer factors(TFs).The PTE concentrations in soils from mining areas were generally higher than a adjacent controlled area,with As and Cd in soils showing the prominent compared to other six PTEs,as seen for the indices of geo-accumulation index(I_(geo)),pollution index(PI)and potential ecological risk index(RI).The relatively high BAF and TF values suggested a distinct biotransfer of PTEs along the soil-plant-leaf litter-earthworm system.BAFs were mostly<1 except in earthworms,indicating that earthworms had a strong capacity to take up these metals.The TFs varied both among PTEs and organism’s species,e.g.,the transfer capacities of As in Pteris vittata and Pteris cretica,Cd in Miscanthus sinensis,and Pb,Cr and Mn in moss were the highest.For local free-range chicken and wild passerine bird,the concentrations of PTEs were higher in gastric contents and feather than in internal tissue(stomach,liver and heart),with lower contents in muscle and egg.Bioaccumulation of PTEs generally decreased from decomposer earthworms,to primary producer plants,to top predator,indicating a potential bio-dilution tendency in higher trophic levels in the terrestrial food chain.展开更多
In this paper,we propose a joint power and frequency allocation algorithm considering interference protection in the integrated satellite and terrestrial network(ISTN).We efficiently utilize spectrum resources by allo...In this paper,we propose a joint power and frequency allocation algorithm considering interference protection in the integrated satellite and terrestrial network(ISTN).We efficiently utilize spectrum resources by allowing user equipment(UE)of terrestrial networks to share frequencies with satellite networks.In order to protect the satellite terminal(ST),the base station(BS)needs to control the transmit power and frequency resources of the UE.The optimization problem involves maximizing the achievable throughput while satisfying the interference protection constraints of the ST and the quality of service(QoS)of the UE.However,this problem is highly nonconvex,and we decompose it into power allocation and frequency resource scheduling subproblems.In the power allocation subproblem,we propose a power allocation algorithm based on interference probability(PAIP)to address channel uncertainty.We obtain the suboptimal power allocation solution through iterative optimization.In the frequency resource scheduling subproblem,we develop a heuristic algorithm to handle the non-convexity of the problem.The simulation results show that the combination of power allocation and frequency resource scheduling algorithms can improve spectrum utilization.展开更多
1.Introduction As a key development of the next-generation spatial information infrastructure,1the Satellite-Terrestrial Integrated Network(STIN)has become a strategic priority actively pursued by major spacefaring na...1.Introduction As a key development of the next-generation spatial information infrastructure,1the Satellite-Terrestrial Integrated Network(STIN)has become a strategic priority actively pursued by major spacefaring nations and regions,including the United States,Europe,China,and Russia.Specifically,Space X’s Starlink project has deployed over 6750 satellites,2while One Web has completed its initial phase of satellite constellation deployment with more than 600 satellites.展开更多
China has implemented large-scale hydraulic engineering projects in arid regions where water resources are severely scarce to efficiently maximize limited water resources for production and domestic needs.The processe...China has implemented large-scale hydraulic engineering projects in arid regions where water resources are severely scarce to efficiently maximize limited water resources for production and domestic needs.The processes and consequences of how the change of hydrological factors affects vegetation distribution remain unclear.This study employed multi-source remote sensing data to investigate the impact of hydrological factors on vegetation distribution in the Shiyang River Basin(SRB)in the arid region in Northwestern China.The results indicate that:(1)The NDVI values in the SRB showed a fluctuating upward trend of(0.0014/yr),with vegetation increase occurring in 62.71%of the area while vegetation degradation was observed in only 6.44%of the area.(2)The Surface Water Storage Anomaly(SWSA)shows an increasing trend of(0.112 mm/month),while Terrestrial Water Storage Anomaly(TWSA)and Groundwater Storage Anomaly(GWSA)exhibit significant declines at rates of-0.124 mm/month and-0.236 mm/month,respectively.(3)Vegetation growth on agricultural land and in planted forests has shown significant growth,in contrast to the general degradation of natural vegetation that is dependent on groundwater.In addition,surface water inputs directly catalyze vegetation growth dynamics.However,the complex mechanisms linking vegetation increase and decreasing terrestrial water reserves in arid regions still need to be studied in depth.The potential negative ecological impacts that may result from the continuous decline of terrestrial and groundwater reserves should not be taken lightly.展开更多
The transpiration-to-evapotranspiration ratio(T/ET)is a crucial indicator of the carbon-water cycle and energy balance.Despite the marked seasonality of warming and greening patterns,the differential responses of T/ET...The transpiration-to-evapotranspiration ratio(T/ET)is a crucial indicator of the carbon-water cycle and energy balance.Despite the marked seasonality of warming and greening patterns,the differential responses of T/ET to environmental changes across the seasons remain unclear.To address this,we employed a model-data fusion method,integrating the Priestley–Taylor Jet Propulsion Lab model with observational datasets,to analyze the seasonal trends of T/ET in China’s terrestrial ecosystems from 1981 to 2021.The results showed that T/ET significantly increased in spring,summer,and autumn,with growth rates of 0.0018 a^(–1)(p<0.01),0.0024 a^(–1)(p<0.01),and 0.0013 a^(–1)(p<0.01),respectively,whereas the winter trends remained statistically insignificant throughout the study period.Leaf area index dynamics were identified as the primary driver of the increase in T/ET during summer,accounting for 79%of the trend.By contrast,climate change was the main contributor to the rising T/ET trends in spring and autumn,accounting for 72%and 77%of the T/ET increase,respectively.Additionally,warming is pivotal for climate-driven changes in T/ET trends.This study elucidated seasonal variations in T/ET responses to environmental factors,offering critical insights for the sustainable management of ecosystems and accurate prediction of future environmental change impacts.展开更多
基金National Key R&D Program of China (2017YFA0503800)National Natural Science Foundation of China (31330048, 31621001 and 31570219)+3 种基金Peking-Tsinghua Center for Life Sciences, US NIH grant (GM-47850)the Jiangsu Province Key Project for Scientific Research (16KJA180002)the Young 日ite Scientists Sponsorship Program and Qing Lan project of Jiangsu Provincethe Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).
文摘Light serves as the source of energy as well as an information signal for photosynthetic plants. During evolution, plants have acquired the ability to monitor environmental light radiation and adjust their developmental patterns to optimally utilize light energy for photosynthesis. The mechanisms of light perception and signal transduction have been comprehensively studied in past decades, mostly in a few model plants, including Arabidopsis thaliana. However, systematic analyses of the origin and evolution of core components involved in light perception and signaling are still lacking. In this study, we took advantage of the recently sequenced genomes and transcriptomes covering all the main Archaeplastida clades in the public domain to identify orthologous genes of core components involved in light perception and signaling and to reconstruct their evolutionary history. Our analyses suggested that acclimation to different distribution of light quality in new environments led to the origination of specific light signaling pathways in plants. The UVR8 (UV Resistance Locus 8) signaling pathway originated during the movement of plants from the deeper sea to shallow water and enabled plants to deal with ultraviolet B light (UV-B). After acquisition of UV-B adaptation, origination of the phytochrome signaling pathway helped plants to colonize water surface where red light became the prominent light energy source. The seedling emergence pathway, which is mediated by a combination of light and phytohormone signals that orchestrate plant growth pattern transitions, originated before the emergence of seed plants. Although cryptochromes and some key components of E3 ubiquitin ligase systems already existed before the divergence of the plant and animal kingdoms, the coevolution and optimization of light perception and downstream signal transduction components, including key transcription factors and E3 ubiquitin ligase systems, are evident during plant terrestrialization.
基金funded by the Postdoctoral Research Startup Foundation of University of Jinan(Grant No.100389917).
文摘Climate change and anthropogenic activities have driven significant terrestrial water storage changes(TWSC)in the Three Rivers Source Region(TRSR),exerting profound impacts on freshwater availability across China and broader Asia.However,long-term TWSC characterization remains challenging due to limited observational data in this alpine region.Here,we integrate GRACE observations(2002-2020),ERA5-Land reanalysis,and GLDAS data to reconstruct TWSC using two methods:(1)the water balance method(PER)and(2)the component summation method(SS),applied to three input datasets(ERA5-Land,GLDAS,and their average,GLER).Comparative analysis reveals that the SS method applied to GL-ER yields the highest consistency with GRACE-derived TWSC.Using this optimal approach,we extend the analysis to 1951~2020,uncovering spatiotemporal TWSC patterns.Although annual TWSC trends appear negligible due to strong seasonality,we introduce the intra-year TWSC fluctuation(TWSCF)index to quantify cumulative variability.A significant(p<0.05)transition occurred in 1980,with TWSCF shifting from a declining trend(-0.39 mm/yr)to an increasing trend(0.56 mm/yr),primarily driven by soil moisture changes.However,Hurst exponent analysis suggests this upward trend may not persist.Drought and vegetation assessments indicate concurrent wetting and greening in the TRSR.TWSC correlates strongly with meteorological drought,acting as a reliable drought indicator while its linkage with vegetation dynamics suggests a potential contribution to greening.Our findings provide a robust framework for understanding long-term TWSC evolution and its hydrological-ecological interactions under climate change.
基金Under the National Key R&D Program Key Project(No.2021YFC3201201)National Natural Science Foundation of China(No.52360032)+2 种基金Basic Scientific Research Business Fee Project of Colleges And Universities Directly Under the Inner Mongolia Autonomous Region(No.JBYYWF2022001)Development Plan of Innovation Team of Colleges And Universities in Inner Mongolia Autonomous Region(No.NMGIRT2313)the Innovation Team of‘Grassland Talents’。
文摘Clarifying the mechanisms through which coal mining affects groundwater storage(GWS)variations is crucial for water resource conservation and sustainable development.The Ordos Mining Region in China,a key energy base in China with significant strategic importance,has undergone intensive coal mining activities that have substantially disrupted regional groundwater circulation.This study integrated data from the Gravity Recovery and Climate Experiment Satellite(GRACE)and Famine Early Warning Systems Network(FEWS NET)Land Data Assimilation System(FLDAS)models,combined with weighted downscaling methodology and water balance principles,to reconstruct high-resolution(0.01°)terrestrial water storage(TWS)and GWS changes in the Ordos Mining Region,China from April 2002 to December 2021.The accuracy of GWS variations were validated through pumping test measurements.Subsequently,Geodetector analysis was implemented to quantify the contributions of natural and anthropogenic factors to groundwater storage dynamics.Key findings include:1)TWS in the study area showed a fluctuating but overall decreasing trend,with a total reduction of 8901.11 mm during study period.The most significant annual decrease occurred in 2021,reaching 1696.77 mm.2)GWS exhibited an accelerated decline,with an average annual change rate of 44.35 mm/yr,totaling a decrease of 887.05 mm.The lowest annual groundwater storage level was recorded in 2020,reaching 185.69 mm.3)Precipitation(PRE)contributed the most to GWS variation(q=0.52),followed by coal mining water consumption(MWS)(q=0.41).The interaction between PRE and MWS exhibited a nonlinear enhancement effect on GWS changes(0.54).The synergistic effect of natural hydrological factors has a great influence on the change of GWS,but coal mining water consumption will continue to reduce GWS.These findings provide critical references for the management and regulation of groundwater resource in mining regions.
文摘Space-Terrestrial Integrated 6G Network:Architecture,Networking,and Transmission Technologies With the large-scale deployment of satellite constellations such as Starlink and the rapid advancement of technologies including artificial intelligence(AI)and non-terrestrial networks(NTNs),the integration of high,medium,and low Earth orbit satellite networks with terrestrial networks has become a critical direction for future communication technologies.
文摘With the large-scale deployment of satellite constellations such as Starlink and the rapid advancement of technologies including artificial intelligence (AI) and non-terrestrial networks (NTNs), the integration of high, medium, and low Earth orbit satellite networks with terrestrial networks has become a critical direction for future communication technologies. The objective is to develop a space-terrestrial integrated 6G network that ensures ubiquitous connectivity and seamless services, facilitating intelligent interconnection and collaborative symbiosis among humans, machines, and objects. This integration has become a central focus of global technological innovation.
文摘Oil tanks are essential components of the oil industry, facilitating the safe storage and transportation of crude oil. Safely managing oil tanks is a crucial aspect of environmental protection. Oil tanks are often used under extreme operational conditions, including dynamic loads, temperature variations, etc., which may result in unpredictable deformations that can cause severe damage or tank collapses. Therefore, it is essential to establish a monitoring system to prevent and predict potential deformations. Terrestrial laser scanning (TLS) has played a significant role in oil tank monitoring over the past decades. However, the full extent of TLS capabilities for oil tank monitoring has not yet been thoroughly investigated. This study aims to evaluate TLS’s abilities in detecting deformations of oil tanks under various operating conditions. The paper has two objectives: first, to examine the deformations of two vertical oil tanks over six years, and second, to investigate potential deformations of the tanks’ surfaces during filling. Each tank was scanned three times—in the years 2015, 2016, and 2021. Mathematical models and appropriate software were developed to determine the achievable accuracy of TLS monitoring. The anticipated monitoring accuracy was simulated based on the design parameters of the oil tanks. This accuracy was subsequently used to differentiate between deformations and measurement errors. The tank surface was approximated utilizing the cylinder equation for each monitoring epoch. Additionally, deformations were analyzed at different cross-sections with the appropriate circular approximations. The results indicated that both tanks exhibited no significant deformations within a range of less than 20 mm. For the empty tanks, the average radius decreased by 4 mm, without any changes in shape. The total spatial inclination of the oil tanks was calculated using cylinder equations at different monitoring epochs. In the final stage, the observed deformations were employed to simulate the strain-stress conditions of the oil tanks. Thus, this paper presents a complex technology and the results of oil tank monitoring by TLS under various operating conditions.
文摘Exoplanet imaging using the solar gravitational lens is an enticing prospect.The fundamental physical properties of the lens,including its angular resolution and light amplification,promise exceptional capabilities.These expectations,however,are tempered by the realization of numerous challenges,including imperfections of the lens itself,noise sources,the properties of the imaging target and difficult technical issues.We discuss,in particular,a subject not previously addressed,the impact of temporally varying surface features,notably a variable cloud cover,obscuring the target exoplanet.This has a substantial detrimental effect on image recovery,leading to our cautious assessment of the practical feasibility of using the Sun’s gravitational field as an effective telescope.
基金National Natural Science Foundation of China(42175022)。
文摘In the context of global warming, the increasing wildfire frequency has become a critical climate research focus in North America. This study used the Community Earth System Model(CESM 1.2) to investigate the impacts of 20thcentury wildfires on North American climate and hydrology. Summer represents the peak wildfire season in North America, with the Gulf of Mexico and Midwest regions experiencing the most severe effects. Wildfires not only damage vegetation during the fire season but also extend prolonged impacts into non-fire periods, showing distinct seasonal variations. In spring, wildfires increase surface albedo, triggering a cooling effect through enhanced snow cover and delayed snowmelt. Conversely, summer and autumn surface warming stems primarily from wildfire-suppressed vegetation transpiration. Warming near the Gulf of Mexico enhances moisture transport and precipitation, particularly in summer and autumn. Reduced evaporation and increased precipitation from the Gulf of Mexico significantly altered the hydrological cycle across North America, leading to increased runoff continent-wide.
基金supported by the National Natural Science Foundation of China Project(32200387)the Emergency Project for Risk Assessment of Areca Nut(Key Project of the Department of Agriculture and Rural Affairs of Hainan Province&Wanning Municipal People’s Government).
文摘Areca nut is the basic ingredient of betel quid,which is chewed by hundreds of millions of people in South-Eastern Asia.Chewing of areca nut has been associated with oral cancers potentially due to its specific alkaloids,among which arecoline constitutes about 90%of total fraction.Being the world’s fourth most commonly used psychoactive substance,arecoline evokes stimulation,addiction,and other direct neurological effects,while its misuse correlates to neurotoxic effects.However,what might underlie its neurotoxic mechanisms has been poorly documented.The brain is encoded by a complex network of neuronal and glial cell types,and neurotoxicity of hazardous compounds present transcriptional heterogeneity.Recently,the eusocial bumblebee has been used as a model for studying brain effects,with sophisticated cognitive capability and precisely measured brain architecture.Here,we decipher cell-type-specific mental risks to arecoline using bumblebees.Arecoline induced locomotor hyperactivity and cognitive impairment.Single nucleus RNA sequencing(snRNA-seq)unearthed arecoline-induced cell-specific responses,primarily targeted on Kenyon cells(KC).Moreover,high-dose arecoline induced distinctive cell responses among KC subtypes,particularly class I large Kenyon cell(lKC),leading to DNA damage,excitatory/inhibitory(E/I)imbalance,and calcium dyshomeostasis,which potentially resulted in cognitive impairment.Given arecoline’s popularity and growing exposure risks to humans,neurological health risks of areca nut warrant serious consideration.
基金supported by the Chinese Scholarship Council under Grant 202106910006.
文摘Branch angles are an important plant morphological trait affecting light interception within forest canopies.However,studies on branch angles have been limited due to the time-consuming nature of manual measurements using a protractor.Terrestrial laser scanning(TLS),however,provides new opportunities to measure branch angles more efficiently.Despite this potential,studies validating branch angle measurements from TLS have been limited.Here,our aim is to evaluate both manual and automatic branch angle measurements of European beech from TLS data using traditional field-measurements with a protractor as a reference.We evaluated the accuracy of branch angle measurements based on four automated algorithms(aRchiQSM,TreeQSM,Laplacian,SemanticLaplacian)from TLS data.Additionally,we assessed different ways of manual branch angle measurements in the field.Our study was based on a dataset comprising 124 branch angles measured from six European beech in a European deciduous forest.Our results show that manual branch angle measurements from TLS data are in high agreement with the reference(root-mean-squared error,RMSE:[3.57°-4.18°],concordance correlation coefficient,CCC:[0.950.97])across different branch length positions.Automated algorithms also are in high agreement with the reference although RMSE is approximately twice as large compared to manual branch angle measurements from TLS(RMSE:[9.29°-10.55°],CCC:[0.830.86])with manual leaf points removal.When applying the automatic wood-leaf separation algorithm,the performance of the four methods declined significantly,with only approximately 20 branch angles successfully identified.Moreover,it is important to note that there is no influence of the measurement position(branch surface versus center)for branch angle measurements.However,for curved branches,the selection of branch measurement length significantly impacts the branch angle measurement.This study provides a comprehensive understanding of branch angle measurements in forests.We show that automated measurement methods based on TLS data of branch angles are a valuable tool to quantify branch angles at larger scales.
基金National Key Research and Development Program of China,No.2020YFA0607700,No.2023YFF0804702National Natural Science Foundation of China,No.T2192954,No.42030507,No.42372352。
文摘To explore the factors controlling human activity in Northeast Asia during the last deglaciation,this study synthesizes six pollen records from lakes and peatlands,alongside four paleotemperature records from terrestrial sedimentary sequences in this region.We simulated potential hunter-gatherer population densities using the Minimalist Terrestrial Resource Model(MTRM),and calculated vegetation openness,rate of change,and evenness based on pollen data.The results reveal a direct relationship between plant resources and hunter-gatherer populations from 20.9 to 10.2 ka BP.The synchronous increases in plant resources and population density from the Last Glacial(LG)to the B?lling-Aller?d(BA)warm period,as well as from the Younger Dryas(YD)to the early Holocene(EH),with stasis during the YD,suggest that resource availability was a key driver of human activity.Redundancy analysis(RDA)of pollen and paleotemperature records indicated that vegetation and plant resources were more closely linked to the mean annual air temperature,with winter characteristics,from the LG to the YD,whereas warm-season temperatures played a more significant role during the EH.This research emphasizes that variations in resource accessibility,rather than direct climate effects alone,were likely pivotal in shaping human activity responses to environmental changes.
基金the funding of the National Natural Science Foundation of China(Nos.42222209,42303056)。
文摘The rhenium-osmium(Re-Os)isotope system is a powerful tool for dating organic-rich sedimentary rocks,yet the mechanisms of Re and Os uptake and their fractionation in different types of organic matter remain poorly understood.Here,we investigate the role of terrestrial organic matter(e.g.,wood of the species Taxodium distichum and charcoal generated from the same species in the laboratory)in Re and Os enrichment and isotope fractionation through laboratory experiments.The results show that charcoal has a significantly higher capacity to uptake both Re(68-77 times greater)and Os(1.7-2.2 times higher)compared to wood,with charcoal preferentially accumulating Re over Os,leading to higher^(187)Re/^(188)Os ratios.These findings highlight the important contribution of terrestrial organic matter,particularly charcoal,to Re and Os concentrations and isotope fractionation in shales,and the importance of organic matter type for chelating Re and Os as previously discussed.Furthermore,we discuss the potential of using Re to track organic carbon weathering,noting that the coupled release of Re and organic carbon during weathering provides new insights into carbon cycling processes.
基金Earthquake Science and Technology Program of Hebei Province under Grant Nos.DZ2021120300001,DZ2024083000001,DZ2024112400016 and DZ2025092800001。
文摘In this study,terrestrial laser scanning(TLS)is used to collect building data after the M_(s) 7.0 magnitude earthquake in Lushan,Sichuan,China in 2013 for analysis and research.The analysis focuses on extracting the tilt and deformation of masonry buildings that are difficult to identify through visual inspection in basically intact,slightly damaged and moderately damaged masonry buildings,to solve the problem of ambiguous identification of damage.A quantitative analysis of the determination indexes of the degree of earthquake damage was carried out,and the numerical characteristics parameters such as the curvature of the wall point cloud proximity,angle,contour of the fitted plane of the point cloud,verticality(flatness)of the wall,standard deviation of the profile and angle of the profile were established to determine the degree of earthquake damage to buildings based on LiDAR data.The development of quantitative determination indexes for the degree of earthquake damage of buildings in this study has important application value for LiDAR data in the identification and extraction of earthquake damage information and damage level determination.
基金supported by the National Natural Science Foundation of China(Nos.41907325 and 41571470).
文摘The present study was conducted to examine the trophic transfer of potentially toxic elements(PTEs)in a closed arsenic mine.Eight PTEs in a soil-plant-leaf litter-earthworm-top predators(free-range local chicken and wild passerine bird)system were analyzed for nitrogen and carbon stable isotopes,PTE concentrations,bioaccumulation factors(BAFs),and transfer factors(TFs).The PTE concentrations in soils from mining areas were generally higher than a adjacent controlled area,with As and Cd in soils showing the prominent compared to other six PTEs,as seen for the indices of geo-accumulation index(I_(geo)),pollution index(PI)and potential ecological risk index(RI).The relatively high BAF and TF values suggested a distinct biotransfer of PTEs along the soil-plant-leaf litter-earthworm system.BAFs were mostly<1 except in earthworms,indicating that earthworms had a strong capacity to take up these metals.The TFs varied both among PTEs and organism’s species,e.g.,the transfer capacities of As in Pteris vittata and Pteris cretica,Cd in Miscanthus sinensis,and Pb,Cr and Mn in moss were the highest.For local free-range chicken and wild passerine bird,the concentrations of PTEs were higher in gastric contents and feather than in internal tissue(stomach,liver and heart),with lower contents in muscle and egg.Bioaccumulation of PTEs generally decreased from decomposer earthworms,to primary producer plants,to top predator,indicating a potential bio-dilution tendency in higher trophic levels in the terrestrial food chain.
基金funded by State Key Laboratory of Micro-Spacecraft Rapid Design and Intelligent Cluster under Grant MS01240103the National Natural Science Foundation of China under Grant 62071146National 2011 Collaborative Innovation Center of Wireless Communication Technologies under Grant 2242022k60006.
文摘In this paper,we propose a joint power and frequency allocation algorithm considering interference protection in the integrated satellite and terrestrial network(ISTN).We efficiently utilize spectrum resources by allowing user equipment(UE)of terrestrial networks to share frequencies with satellite networks.In order to protect the satellite terminal(ST),the base station(BS)needs to control the transmit power and frequency resources of the UE.The optimization problem involves maximizing the achievable throughput while satisfying the interference protection constraints of the ST and the quality of service(QoS)of the UE.However,this problem is highly nonconvex,and we decompose it into power allocation and frequency resource scheduling subproblems.In the power allocation subproblem,we propose a power allocation algorithm based on interference probability(PAIP)to address channel uncertainty.We obtain the suboptimal power allocation solution through iterative optimization.In the frequency resource scheduling subproblem,we develop a heuristic algorithm to handle the non-convexity of the problem.The simulation results show that the combination of power allocation and frequency resource scheduling algorithms can improve spectrum utilization.
基金co-supported by the National Natural Science Foundation of China(Nos.62225103,U2441227,U24A20211)the Fundamental Research Funds for the Central Universities of China(No.FRF-TP-22-002C2)。
文摘1.Introduction As a key development of the next-generation spatial information infrastructure,1the Satellite-Terrestrial Integrated Network(STIN)has become a strategic priority actively pursued by major spacefaring nations and regions,including the United States,Europe,China,and Russia.Specifically,Space X’s Starlink project has deployed over 6750 satellites,2while One Web has completed its initial phase of satellite constellation deployment with more than 600 satellites.
基金financially supported by the National Natural Science Foundation of China(42371040,41971036)Key Natural Science Foundation of Gansu Province(23JRRA698)+2 种基金Key Research and Development Program of Gansu Province(22YF7NA122)Cultivation Program of Major key projects of Northwest Normal University(NWNU-LKZD-202302)Oasis Scientific Research achievements Breakthrough Action Plan Project of Northwest normal University(NWNU-LZKX-202303).
文摘China has implemented large-scale hydraulic engineering projects in arid regions where water resources are severely scarce to efficiently maximize limited water resources for production and domestic needs.The processes and consequences of how the change of hydrological factors affects vegetation distribution remain unclear.This study employed multi-source remote sensing data to investigate the impact of hydrological factors on vegetation distribution in the Shiyang River Basin(SRB)in the arid region in Northwestern China.The results indicate that:(1)The NDVI values in the SRB showed a fluctuating upward trend of(0.0014/yr),with vegetation increase occurring in 62.71%of the area while vegetation degradation was observed in only 6.44%of the area.(2)The Surface Water Storage Anomaly(SWSA)shows an increasing trend of(0.112 mm/month),while Terrestrial Water Storage Anomaly(TWSA)and Groundwater Storage Anomaly(GWSA)exhibit significant declines at rates of-0.124 mm/month and-0.236 mm/month,respectively.(3)Vegetation growth on agricultural land and in planted forests has shown significant growth,in contrast to the general degradation of natural vegetation that is dependent on groundwater.In addition,surface water inputs directly catalyze vegetation growth dynamics.However,the complex mechanisms linking vegetation increase and decreasing terrestrial water reserves in arid regions still need to be studied in depth.The potential negative ecological impacts that may result from the continuous decline of terrestrial and groundwater reserves should not be taken lightly.
基金National Natural Science Foundation of China,No.42201312,No.42301538Natural Science Foundation of Shandong Province,No.ZR2022QD118。
文摘The transpiration-to-evapotranspiration ratio(T/ET)is a crucial indicator of the carbon-water cycle and energy balance.Despite the marked seasonality of warming and greening patterns,the differential responses of T/ET to environmental changes across the seasons remain unclear.To address this,we employed a model-data fusion method,integrating the Priestley–Taylor Jet Propulsion Lab model with observational datasets,to analyze the seasonal trends of T/ET in China’s terrestrial ecosystems from 1981 to 2021.The results showed that T/ET significantly increased in spring,summer,and autumn,with growth rates of 0.0018 a^(–1)(p<0.01),0.0024 a^(–1)(p<0.01),and 0.0013 a^(–1)(p<0.01),respectively,whereas the winter trends remained statistically insignificant throughout the study period.Leaf area index dynamics were identified as the primary driver of the increase in T/ET during summer,accounting for 79%of the trend.By contrast,climate change was the main contributor to the rising T/ET trends in spring and autumn,accounting for 72%and 77%of the T/ET increase,respectively.Additionally,warming is pivotal for climate-driven changes in T/ET trends.This study elucidated seasonal variations in T/ET responses to environmental factors,offering critical insights for the sustainable management of ecosystems and accurate prediction of future environmental change impacts.
