This study aims to construct a large-scale hydrological Variable Infiltration Capacity(VIC)model based on temperature and precipitation at high altitudes,while elucidating the applicability of the model for hydrologic...This study aims to construct a large-scale hydrological Variable Infiltration Capacity(VIC)model based on temperature and precipitation at high altitudes,while elucidating the applicability of the model for hydrological simulation and analyzing the factors affecting runoff volume.Runoff volume and runoff depth were simulated using the VIC model and its performance was evaluated.Meanwhile,the factors affecting runoff volume were analyzed using Spearman correlation.The following model sensitivity parameters were obtained based on the China Natural Runoff Grid Point Dataset(CNRD v1.0):The variable infiltration curve parameter was 0.3,the Dsmax fraction where non-linear baseflow begins was 0.02,the maximum baseflow velocity was 15 mm/d,the maximum soil moisture where non-linear baseflow occurred was 0.7,the second soil moisture layer thickness was 0.3,and the thickness of the third soil moisture layer was 1.5.The surface runoff values in the Nyang River basin were similar in the first and fourth quarters(1.05–2.27 mm and 2.38–4.77 mm,respectively),and the surface runoff values were similar in the second and third quarters when the surface runoff was greater(23.46–52.20 mm and 60.59–85.63 mm,respectively).Watershed area,temperature,and precipitation significantly influenced the amount of runoff from the Nyang River.The applicability of the model to the Nyang River basin was confirmed using two different rate models.In some areas,precipitation and temperature did not have a dominating influence on runoff.Although the VIC model has significant advantages in runoff simulation,it requires a wealth of meteorological,soil,and hydrological data that may be difficult to obtain in some areas.展开更多
On September 5, 2022, an earthquake of magnitude M_(S)6.8 occurred in Luding County, Sichuan Province.This earthquake occurred at the key part of the southeast-clockwise extrusion of material on the eastern margin of ...On September 5, 2022, an earthquake of magnitude M_(S)6.8 occurred in Luding County, Sichuan Province.This earthquake occurred at the key part of the southeast-clockwise extrusion of material on the eastern margin of the Qinghai Plateau, the Y-shaped confluence of the Xianshuihe, Longmenshan and Anninghe fault zones. In this study, the three-dimensional dynamic crustal density changes in the earthquake area are obtained by the typical gravity change data from 2019 to 2022 before the earthquake and gravity inversion by growing bodies. The results indicate that gravity changes presented an obvious fourquadrant and gradient belt distribution in the Luding area before the earthquake. The threedimensional density horizontal slices show that small density changes occurred at the epicenter in the mid-to-upper crust between 2019.9-2020.9 and 2019.9-2021.9. At the same time, the surrounding areas exhibited a positive and negative quadrant distribution. These observations indicate that the source region was likely in a stable locked state, with locking-in shear forces oriented in the NW and NE directions. From 2021.9 to 2022.8, the epicentral region showed negative density changes, indicating that the source region was in the expansion stage, approaching a near-seismic state. The three-dimensional density vertical slices reveal a southeastward migration of positive and negative densities near the epicenter and on the western of the Xianshuihe Fault Zone, indicating that the material is flowing out to the southeast. The observed local negative density changes at the epicenter along the Longmenshan Fault Zone are likely associated with the NE-oriented extensional stress shown by the seismic source mechanism. The above results can provide a basis for interpreting pre-earthquake gravity and density changes,thereby contributing to the advancement of earthquake precursor theory.展开更多
BACKGROUND Atypical optic neuritis,consisting of neuromyelitis optica spectrum disorders(NMOSD)or myelin oligodendrocyte glycoprotein antibody disease(MOGAD),has a very similar presentation but different prognostic im...BACKGROUND Atypical optic neuritis,consisting of neuromyelitis optica spectrum disorders(NMOSD)or myelin oligodendrocyte glycoprotein antibody disease(MOGAD),has a very similar presentation but different prognostic implications and longterm management strategies.Vascular and metabolic factors are being thought to play a role in such autoimmune neuro-inflammatory disorders,apart from the obvious immune mediated damage.With the advent of optical coherence tomography angiography(OCTA),it is easy to pick up on these subclinical macular microvascular and structural changes.AIM To study the macular microvascular and structural changes on OCTA in atypical optic neuritis.METHODS This observational cross-sectional study involved 8 NMOSD and 17 MOGAD patients,diagnosed serologically,as well as 10 healthy controls.Macular vascular density(MVD)and ganglion cell+inner plexiform layer thickness(GCIPL)were studied using OCTA.RESULTS There was a significant reduction in MVD in NMOSD and MOGAD affected as well as unaffected eyes when compared with healthy controls.NMOSD and MOGAD affected eyes had significant GCIPL thinning compared with healthy controls.NMOSD unaffected eyes did not show significant GCIPL thinning compared to healthy controls in contrast to MOGAD unaffected eyes.On comparing NMOSD with MOGAD,there was no significant difference in terms of MVD or GCIPL in the affected or unaffected eyes.CONCLUSION Although significant microvascular and structural changes are present on OCTA between atypical optic neuritis and normal patients,they could not help in differentiating between NMOSD and MOGAD cases.展开更多
Terrestrial ecosystems heavily depend on vegetation,which responds to carbon dioxide(CO_(2))fertilization in hot and humid regions.The subtropical humid karst region is a hot and humid region;whether and to what exten...Terrestrial ecosystems heavily depend on vegetation,which responds to carbon dioxide(CO_(2))fertilization in hot and humid regions.The subtropical humid karst region is a hot and humid region;whether and to what extent CO_(2)fertilization affects vegetation changes in such regions remains unclear.In this study,we investigated the degree to which CO_(2)fertilization influences vegetation changes,along with their spatial and temporal differences,in the subtropical humid karst region using time-lag effect analysis,a random forest model,and multiple regression analysis.Results showed that CO_(2)fertilization plays an important role in vegetation changes,exhibiting clear spatial variations across different geomorphological zones,with its degree of influence ranging mainly between 11%and 25%.The highest contribution of CO_(2)fertilization was observed in the karst basin and non-karstic region,whereas the lowest contribution was found in the karst plateau region.Previous studies have primarily attributed vegetation changes in subtropical humid karst region to ecological engineering,leading to an overestimation of its contribution to these changes.The findings of this study enhance the understanding of the mechanism of vegetation changes in humid karst region and provide theoretical and practical insights for ecological and environmental protection in these regions.展开更多
Previous works were mainly concentrated on long-term average runoff alterations,and extreme temperatures and watershed conditions are little analyzed.In this study,we collected gauged river flow and meteorological dat...Previous works were mainly concentrated on long-term average runoff alterations,and extreme temperatures and watershed conditions are little analyzed.In this study,we collected gauged river flow and meteorological data time series from 1916 to 2015 and 1941 to 2015 across the contiguous United States(CONUS)for 188 catchments to investigate the temporal trends and spatial features of runoff changes at multi-time scales.We also analyzed the relationships between runoff changes and climatic factors.Median descriptive statistics and Budyko coupled climate elasticity methods were used to calculate runoff elasticity in each time scale.The original Mann-Kendall trend test was used to test their trend significance in four time-scale(11,20,40,and 60 a),respectively.The results show that the trend of runoff changes is more significant in high time scales;total changes are heterogeneous over CONUS.After the 1970s,increases of up to 27%decade-1 were mainly concentrated in the mid-northern regions.Maximum temperature and catchment characteristics are vital factors for runoff alteration;runoff changes are independent of rainfall,and wet regions tend to have lower changes.These findings could help develop better regional water resource planning and management.展开更多
Objective:To investigate the diagnostic value of magnetic resonance imaging(MRI)in patients with Modic changes and endplate sclerosis of the lumbar spine.Methods:A total of 66 patients with lumbar spine diseases who u...Objective:To investigate the diagnostic value of magnetic resonance imaging(MRI)in patients with Modic changes and endplate sclerosis of the lumbar spine.Methods:A total of 66 patients with lumbar spine diseases who underwent MRI and CT diagnostic examinations at the hospital from May 2024 to April 2025 were included in this study.The MRI findings of Modic changes were compared between Type I and Type II patients,and the presence or absence of endplate sclerosis signals and the HU value ratio on CT were analyzed.The pathological characteristics of Modic changes in Type I and Type II patients were observed.The imaging features of Modic changes in patients with lumbar spine diseases were analyzed.Results:Modic changes were present in 34 patients,with a total of 204 endplates evaluated,of which 74 were affected.MRI classification showed:Type I in 8 cases(10.81%),Type I/II mixed in 10 cases(13.51%),Type II in 51 cases(68.92%),and Type II/III mixed in 5 cases(6.76%).In CT reconstruction images,26 endplates with Modic changes on MRI showed sclerosis in the vertebral body,presenting high-density sclerotic features.These sclerotic areas did not exhibit distinct signal characteristics on MRI but pathologically demonstrated Type II Modic changes concurrently with fatty degeneration and sclerosis;In patients with Modic changes of Type I and Type II,regardless of the presence or absence of endplate sclerosis,the sagittal T1/T2 signal intensity ratio showed no statistically significant difference(P>0.05).However,the HU value ratio in Type II changes with sclerotic regions(2.74±0.61)was significantly higher than that in regions without sclerosis(1.16±0.23),with a statistically significant difference(P<0.05).Conclusion:CT reconstruction images of patients with lumbar Modic changes clearly demonstrate endplate sclerosis,a phenomenon closely associated with the bone marrow repair process.MRI has limited sensitivity for detecting sclerosis,potentially due to the following factors:first,differences in the radiographic characterization of endplate mineral content;second,the specific influence of different Modic types on signal intensity.This suggests that MRI classification should be combined with CT features for comprehensive interpretation.展开更多
Understanding the local ecological security status and its underlying drivers can be used as an effective reference for balancing ecosystem development with societal needs. This study assesses the ecological security ...Understanding the local ecological security status and its underlying drivers can be used as an effective reference for balancing ecosystem development with societal needs. This study assesses the ecological security of the Loess Plateau(LP) by integrating ecosystem health and ecosystem services, explores the varying impacts of ecosystem structure, quality, and services on ecological security index(ESI), and identifies the key driving factors of ESI using the Geodetector model. The results show that:(1) the average ESI indicates a relatively safe ecological status in LP with a significant increase in ESI observed in 50.21% of the region, largely due to the ecological restoration programs.(2) Natural factors predominantly influence ESI, although human factors play a significant role in the earthy-rocky mountain region and plateau wind-sand region.(3) The interactions between driving factors have a much greater impact on ESI than any single factor, with the interactions between precipitation and human factors being the most influential combination. This study provides a novel perspective on assessing ecological security in LP. We recommend that future ecological restoration efforts should consider the varying roles of ecosystem structure, quality, and services in ESI while tailoring strategies to the primary driving factors based on local conditions.展开更多
Language policies are of great significance to a nation’s stability,unity,and development.Uzbekistan’s language policies have reflected the political,economic,and cultural dynamics of different periods throughout hi...Language policies are of great significance to a nation’s stability,unity,and development.Uzbekistan’s language policies have reflected the political,economic,and cultural dynamics of different periods throughout historical changes,influencing social structures and ethnic relations.This paper summarizes the characteristics of Uzbekistan’s language policies in different eras:During the Tsarist Russian period,the Russification of language policies hindered the development of local languages;in the Soviet era,policies adopted a dual approach,promoting both Russian and prioritizing ethnic languages;after independence,Uzbekistan established Uzbek as the state language and emphasized foreign language education.The current language policy in Uzbekistan presents a complex landscape:While emphasizing the dominant role of the national language helps preserve its heritage,it may easily spark ethnic and political tensions;promoting pluralism and inclusivity brings benefits but faces challenges in balancing language statuses,resource allocation,management,and communication;modernization efforts encounter difficulties in standardizing dialects and foreign loanwords;and in international exchanges,there is a need to balance relations with global lingua francas.In conclusion,Uzbekistan’s language policies have undergone unique transformations and face numerous challenges.In-depth research is crucial for improving the country’s policies and enhancing China-Uzbekistan cooperation.Proactive measures are needed to address these challenges,ensuring the sustainability of language policies and fostering greater national prosperity.展开更多
BACKGROUND Gastric bezoars are masses of indigestible material that accumulate in the stomach,causing nausea,abdominal pain,and vomiting.Persimmon bezoars(diospyrobezoars),which comprise tannins and fibers from persim...BACKGROUND Gastric bezoars are masses of indigestible material that accumulate in the stomach,causing nausea,abdominal pain,and vomiting.Persimmon bezoars(diospyrobezoars),which comprise tannins and fibers from persimmons,are relatively rare but may cause significant gastric complications,including gastric outlet obstruction or ileus.Although computed tomography(CT)is a useful ima-ging tool,diagnosing bezoars can be challenging because their density is similar to that of food debris and gastric content.CASE SUMMARY Here,we report the case of a 72-year-old woman with a persimmon bezoar that was diagnosed using serial CT imaging and confirmed by endoscopy.CT perfor-med over several months revealed changes in the internal structure and density of the bezoar,suggesting progressive hardening.The patient had a history of a par-tial gastrectomy and excessive persimmon consumption,both of which are risk factors for bezoar formation.Endoscopic fragmentation of the bezoar successfully resolved symptoms.CONCLUSION Gastric bezoars,particularly persimmon bezoars,present diagnostic challenges because of their variable imaging characteristics.Serial CT can document tem-poral changes in bezoar density,potentially reflecting changes in hardness.Early diagnosis and endoscopic treatment are essential for effective management,particularly in patients with predisposing factors.This case underscores the im-portance of considering bezoars in the differential diagnosis of gastric masses,and highlights the value of CT for monitoring changes in bezoar characteristics over time.展开更多
Fear memory,a predictive and protective mechanism in potentially hostile environments,elicits defensive behavioral responses that have evolved to help organisms avoid harm and ensure survival.However,excessive fear me...Fear memory,a predictive and protective mechanism in potentially hostile environments,elicits defensive behavioral responses that have evolved to help organisms avoid harm and ensure survival.However,excessive fear memories may contribute to the onset of various psychological disorders,such as panic disorder,phobias,and post-traumatic stress disorder(PTSD).展开更多
Transformations of the world unseen in a century are unfolding at a faster pace.Changes of the world,of our times,and of the historical trajectory are taking place in ways like never before.As the new round of technol...Transformations of the world unseen in a century are unfolding at a faster pace.Changes of the world,of our times,and of the historical trajectory are taking place in ways like never before.As the new round of technological revolution and industrial transformation advances,the international power structure and world order are undergoing tectonic realignments and constantly being reshaped.The protracted Ukraine crisis and the escalating Palestinian-Israeli conflict exemplify the intensification of major-power strategic rivalries and geopolitical conflicts.At the same time,non-traditional security issues are getting severe and more deeply intertwined with traditional security.Challenges such as climate change,cybersecurity,energy security,and food security are becoming critical global issues which confront humanity with unprecedented threats and herald a new era of instability and transformation for the world’s development.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
This study analyzed ambient seismic noise using the MSNoise package to monitor temporal changes in the underground seismic wave velocity in Mining Area 6 of the Dongtan Coal Mine in China.The data was recorded continu...This study analyzed ambient seismic noise using the MSNoise package to monitor temporal changes in the underground seismic wave velocity in Mining Area 6 of the Dongtan Coal Mine in China.The data was recorded continuously over 76 days by 7 three-component stations and 10 single-component microseismic stations deployed in Dongtan Coal Mine,with station spacing ranging from 0.1 km to approximately 3 km.Using the causal and non-causal components of the Z-component cross-correlation function,along with moving-window cross-spectrum analysis and cumulative calculations with a 5-day window overlay,stable seismic velocity changes were obtained in the frequency band of 0.1 to 2 Hz.We found a correlation between the timing of average velocity changes and seismic events caused by underground mining processes.In particular,when the relative seismic velocity increased by 0.23%,larger energy minequakes typically occurred.This study shows that ambient noise correlation has great potential for predicting minequakes,guiding pressure-relief production,and providing warnings about the impact of overburden pressure.展开更多
The Antarctic Slope Current(ASC)links the processes occurring in the coast area with the global ocean by modulating the flow across the continental slope,which influences global overturning circulation and the mass ba...The Antarctic Slope Current(ASC)links the processes occurring in the coast area with the global ocean by modulating the flow across the continental slope,which influences global overturning circulation and the mass balance of the Antarctic ice shelves.This paper aims to explore the effects of wind and buoyancy fluxes on the long-term changes in the ASC using observation and reanalysis datasets.From 1993 to 2022,the ASC accelerated in all seasons,particularly in austral autumn,and was accompanied with the advancement of the strong flow.The positive buoyancy flux anomaly generates a low-density anomaly,which is accumulated by the prevailing surface easterly,maintaining a sharp density front along the continental slope.The heat flux intensifies the positive trend of buoyancy flux in summer and autumn,increasing the input of the lighter density anomaly into the ocean and advancing the strong flow of ASC.Compared with the annual mean,the additional acceleration of the ASC in autumn is mainly due to the contribution of the barotropic component,which could be explained by the local momentum input from the weakly enhanced local surface wind.The acceleration of the ASC is primarily driven by the positive trend of the buoyancy flux,while the influence of the wind on its seasonal variability becomes more significant due to the contribution of the local surface wind in autumn.展开更多
Magnesium-based hydrogen storage materials are promising candidates for hydrogen storage due to their high storage density and environmentally friendly properties.However,the high dehydrogenation enthalpy change(appro...Magnesium-based hydrogen storage materials are promising candidates for hydrogen storage due to their high storage density and environmentally friendly properties.However,the high dehydrogenation enthalpy change(approximately 75 kJ/mol H_(2))and high dehydrogenation temperature(573 K at 0.1 MPa)of MgH_(2),limits the engineering application of Mg/MgH_(2) as a hydrogen storage material.This work reviews the prediction models and methods of enthalpy changes for hydriding/dehydriding(H/D)reactions in order to find out the ideas and ways to reduce them.The mechanism behind the improvement methods mainly includes two aspects,weakening Mg-H bond and compensating heat of reaction.Proceed from this,the experimental methods and enthalpy data as well as calculated values of enthalpy changes were compared systematically.Elements such as Ti,Nb,V,etc.,with a small electronegativity difference compared to Mg,can reduce the hydrogenation and dehydrogenation enthalpy changes by forming strong Metal-H or Metal-Mg bonds.In addition,this review concludes with an outlook on the remaining challenge issues and prospects.展开更多
On February 6,2023,the Türkiye Earthquake Doublet,consisting of two major earthquakes with magnitudes of M_(W)7.8 and M_(W)7.5,respectively,occurred within 9 h and devastated the Kahramanmaraşprovince in southwes...On February 6,2023,the Türkiye Earthquake Doublet,consisting of two major earthquakes with magnitudes of M_(W)7.8 and M_(W)7.5,respectively,occurred within 9 h and devastated the Kahramanmaraşprovince in southwest Turkey.The geodynamic background of this area is exceedingly complicated owing to the combined action of the Anatolian Plate and the neighboring Eurasian,African,and Arabian plates,which contain many faults,the most prominent of which is the East Anatolian Fault Zone(EAFZ).These two earthquakes occurred on the Pazarcık Segment(PAZ.S)of the EAFZ and theÇardak Fault(CAR.F).The investigation of co-seismic changes in the velocity structure of the subterranean medium inside the focus area is critical for our understanding of earthquake ruptures.We chose 51572 travel times before the earthquake doublet from January 1,2014,to February 5,2023,and 88371 travel times after the earthquakes from February 6 to March 5,2023,and utilized time-lapse tomography to derive the co-seismic changes in P-wave velocity.The results demonstrated that the P-wave velocity decreased around the center zone,with considerable surface displacement from the two earthquakes caused by rock breakup and stress release.The P-wave velocity increased in two areas:east of the Pazarcik Earthquake,where the Bozova Fault is located,and west of the Elbistan Earthquake.We believe that these two locations are compression zones generated by the strike-slip surface displacement.Similarly,the decrease in velocity in the areas adjacent to the Malatya Fault(MAL.F)and between the Amanos Segment(AM.S)of the EAFZ and the Savur Fault(SA.F)shows that these two locations were exposed to tension as a result of the co-seismic horizontal displacement on the surface.This study showed that in addition to the area close to the epicenter,the large earthquake can affect the velocity structure of faults far away from the main shock.展开更多
This study examined the positive changes that water-based nail treatments can bring to emotions and behavior in children who do not attend school and use a place for school-refusing children.Children who do not attend...This study examined the positive changes that water-based nail treatments can bring to emotions and behavior in children who do not attend school and use a place for school-refusing children.Children who do not attend school and use a place for school-refusing children were given water-based nail treatments about once a week for three months.In addition,the parents of these children were asked to respond to questions about their children’s daily activities.The results showed that natural communication through nail treatments significantly increased positive emotions.However,continued nail treatments did not reduce the children’s problem behaviors.Some children returned to school,while others continued not attending school.Increased frequency of visits and number of treatments confirmed the promotion of communication.It was suggested that building positive relationships with family and supporters is important for achieving sustained effects from nail treatments.This study showed that nail treatments are a useful tool for promoting positive emotions,self-acceptance,and social skills,and may contribute to the emotional growth and social interest of children who do not attend school.展开更多
[Objectives] To analyze the dynamic changes of maximum vegetation coverage in Ili River Basin from 2006 to 2020,and to explore the vegetation change and its influencing factors in the forest-grassland ecotone of Ili r...[Objectives] To analyze the dynamic changes of maximum vegetation coverage in Ili River Basin from 2006 to 2020,and to explore the vegetation change and its influencing factors in the forest-grassland ecotone of Ili region.[Methods] The pixel dichotomy model was used to process the MODIS data and analyze the change of vegetation coverage in the Ili River Basin from 2006 to 2020.[Results] (i)The vegetation coverage in the Ili River Basin increases gradually from west to east,and fluctuates greatly between years.(ii)By monitoring the change rate of the maximum vegetation coverage,it is found that the vegetation coverage of the basin has experienced a process of first decline and then recovery in the past 15 years.(iii)In spatial distribution,vegetation coverage has improved in some regions,while it has deteriorated in others,which may be related to regional climate change and human activities.[Conclusions] The vegetation coverage in the Ili River Basin showed significant spatial and temporal differences during the study period,and its changes were affected by both natural and human factors.展开更多
The toxicity of PM_(2.5)does not necessarily change synchronously with its mass concentration.In this study,the chemical composition(carbonaceous species,water-soluble ions,and metals)and oxidative potential(dithiothr...The toxicity of PM_(2.5)does not necessarily change synchronously with its mass concentration.In this study,the chemical composition(carbonaceous species,water-soluble ions,and metals)and oxidative potential(dithiothreitol assay,DTT)of PM_(2.5)were investigated in 2017/2018 and 2022 in Xiamen,China.The decrease rate of volume-normalized DTT(DTTv)(38%)was lower than that of PM_(2.5)(55%)between the two sampling periods.However,the mass-normalized DTT(DTTm)increased by 44%.Clear seasonal patterns with higher levels in winter were found for PM_(2.5),most chemical constituents and DTTv but not for DTTm.The large decrease in DTT activity(84%−92%)after the addition of EDTA suggested that watersoluble metals were the main contributors to DTT in Xiamen.The increased gap between the reconstructed and measured DTTv and the stronger correlations between the reconstructed/measured DTT ratio and carbonaceous species in 2022were observed.The decrease rates of the hazard index(32.5%)and lifetime cancer risk(9.1%)differed from those of PM_(2.5)and DTTv due to their different main contributors.The PMF-MLR model showed that the contributions(nmol/(min·m^(3)))of vehicle emission,coal+biomass burning,ship emission and secondary aerosol to DTTv in 2022 decreased by 63.0%,65.2%,66.5%,and 22.2%,respectively,compared to those in 2017/2018,which was consistent with the emission reduction of vehicle exhaust and coal consumption,the adoption of low-sulfur fuel oil used on board ships and the reduced production of WSOC.However,the contributions of dust+sea salt and industrial emission increased.展开更多
Gas-bearing shales have become a major source of future natural gas production worldwide.It has become increasingly urgent to develop a reliable prediction model and corresponding workflow for identifying shale gas sw...Gas-bearing shales have become a major source of future natural gas production worldwide.It has become increasingly urgent to develop a reliable prediction model and corresponding workflow for identifying shale gas sweet spots.The formation of gas-bearing shales is closely linked to relative sealevel changes,providing an important approach to predicting sweet spots in the Wufeng-Longmaxi shale in the southern Sichuan Basin,China.Three types of marine shale gas sweet spots are identified in the shale based on their formation stages combined with relative sea-level changes:early,middle,and late transgression types.This study develops a prediction model and workflow for identifying shale gas sweet spots by analyzing relative sea-level changes and facies sequences.Predicting shale gas sweet spots in an explored block using this model and workflow can provide a valuable guide for well design and hydraulic fracturing,significantly enhancing the efficiency of shale gas exploration and development.Notably,the new prediction model and workflow can be utilized for the rapid evaluation of the potential for shale gas development in new shale gas blocks or those with low exploratory maturity.展开更多
基金supported by the Key R&D Project of Science and Technology Program of Tibet Autonomous Region(XZ202301ZY0006G)the Graduate High-level Talent Training Program of Xizang University(2022-GSP-B007)+1 种基金Nagqu City Science and Technology Program Key R&D Projects(NQKJ-2023-15)Central Financial Support for Local Universities to Construct Wetland Station in Mitika and Collaborative Innovation Center for Ecological Civilization of the Qinghai-Tibetan Plateau([2024]NO.01).
文摘This study aims to construct a large-scale hydrological Variable Infiltration Capacity(VIC)model based on temperature and precipitation at high altitudes,while elucidating the applicability of the model for hydrological simulation and analyzing the factors affecting runoff volume.Runoff volume and runoff depth were simulated using the VIC model and its performance was evaluated.Meanwhile,the factors affecting runoff volume were analyzed using Spearman correlation.The following model sensitivity parameters were obtained based on the China Natural Runoff Grid Point Dataset(CNRD v1.0):The variable infiltration curve parameter was 0.3,the Dsmax fraction where non-linear baseflow begins was 0.02,the maximum baseflow velocity was 15 mm/d,the maximum soil moisture where non-linear baseflow occurred was 0.7,the second soil moisture layer thickness was 0.3,and the thickness of the third soil moisture layer was 1.5.The surface runoff values in the Nyang River basin were similar in the first and fourth quarters(1.05–2.27 mm and 2.38–4.77 mm,respectively),and the surface runoff values were similar in the second and third quarters when the surface runoff was greater(23.46–52.20 mm and 60.59–85.63 mm,respectively).Watershed area,temperature,and precipitation significantly influenced the amount of runoff from the Nyang River.The applicability of the model to the Nyang River basin was confirmed using two different rate models.In some areas,precipitation and temperature did not have a dominating influence on runoff.Although the VIC model has significant advantages in runoff simulation,it requires a wealth of meteorological,soil,and hydrological data that may be difficult to obtain in some areas.
基金the National Natural Science Foundation of China(Grant No.42374105,42204089,42174104)Scientific Research Fund of Institute of Seismology,China Earthquake Administration(Grant No.IS202326341,IS202336350).
文摘On September 5, 2022, an earthquake of magnitude M_(S)6.8 occurred in Luding County, Sichuan Province.This earthquake occurred at the key part of the southeast-clockwise extrusion of material on the eastern margin of the Qinghai Plateau, the Y-shaped confluence of the Xianshuihe, Longmenshan and Anninghe fault zones. In this study, the three-dimensional dynamic crustal density changes in the earthquake area are obtained by the typical gravity change data from 2019 to 2022 before the earthquake and gravity inversion by growing bodies. The results indicate that gravity changes presented an obvious fourquadrant and gradient belt distribution in the Luding area before the earthquake. The threedimensional density horizontal slices show that small density changes occurred at the epicenter in the mid-to-upper crust between 2019.9-2020.9 and 2019.9-2021.9. At the same time, the surrounding areas exhibited a positive and negative quadrant distribution. These observations indicate that the source region was likely in a stable locked state, with locking-in shear forces oriented in the NW and NE directions. From 2021.9 to 2022.8, the epicentral region showed negative density changes, indicating that the source region was in the expansion stage, approaching a near-seismic state. The three-dimensional density vertical slices reveal a southeastward migration of positive and negative densities near the epicenter and on the western of the Xianshuihe Fault Zone, indicating that the material is flowing out to the southeast. The observed local negative density changes at the epicenter along the Longmenshan Fault Zone are likely associated with the NE-oriented extensional stress shown by the seismic source mechanism. The above results can provide a basis for interpreting pre-earthquake gravity and density changes,thereby contributing to the advancement of earthquake precursor theory.
文摘BACKGROUND Atypical optic neuritis,consisting of neuromyelitis optica spectrum disorders(NMOSD)or myelin oligodendrocyte glycoprotein antibody disease(MOGAD),has a very similar presentation but different prognostic implications and longterm management strategies.Vascular and metabolic factors are being thought to play a role in such autoimmune neuro-inflammatory disorders,apart from the obvious immune mediated damage.With the advent of optical coherence tomography angiography(OCTA),it is easy to pick up on these subclinical macular microvascular and structural changes.AIM To study the macular microvascular and structural changes on OCTA in atypical optic neuritis.METHODS This observational cross-sectional study involved 8 NMOSD and 17 MOGAD patients,diagnosed serologically,as well as 10 healthy controls.Macular vascular density(MVD)and ganglion cell+inner plexiform layer thickness(GCIPL)were studied using OCTA.RESULTS There was a significant reduction in MVD in NMOSD and MOGAD affected as well as unaffected eyes when compared with healthy controls.NMOSD and MOGAD affected eyes had significant GCIPL thinning compared with healthy controls.NMOSD unaffected eyes did not show significant GCIPL thinning compared to healthy controls in contrast to MOGAD unaffected eyes.On comparing NMOSD with MOGAD,there was no significant difference in terms of MVD or GCIPL in the affected or unaffected eyes.CONCLUSION Although significant microvascular and structural changes are present on OCTA between atypical optic neuritis and normal patients,they could not help in differentiating between NMOSD and MOGAD cases.
基金National Natural Science Foundation of China,No.41761003The Karst Science Research Center of Guizhou Province,No.U1812401。
文摘Terrestrial ecosystems heavily depend on vegetation,which responds to carbon dioxide(CO_(2))fertilization in hot and humid regions.The subtropical humid karst region is a hot and humid region;whether and to what extent CO_(2)fertilization affects vegetation changes in such regions remains unclear.In this study,we investigated the degree to which CO_(2)fertilization influences vegetation changes,along with their spatial and temporal differences,in the subtropical humid karst region using time-lag effect analysis,a random forest model,and multiple regression analysis.Results showed that CO_(2)fertilization plays an important role in vegetation changes,exhibiting clear spatial variations across different geomorphological zones,with its degree of influence ranging mainly between 11%and 25%.The highest contribution of CO_(2)fertilization was observed in the karst basin and non-karstic region,whereas the lowest contribution was found in the karst plateau region.Previous studies have primarily attributed vegetation changes in subtropical humid karst region to ecological engineering,leading to an overestimation of its contribution to these changes.The findings of this study enhance the understanding of the mechanism of vegetation changes in humid karst region and provide theoretical and practical insights for ecological and environmental protection in these regions.
基金supported by National Key R&D Program of China(No.2018YFC0407303)“Young Talents”Project of Northeast Agricultural University(No.20QC13)the Natural Science Foundation of Heilongjiang Province of China(No.E2017009)。
文摘Previous works were mainly concentrated on long-term average runoff alterations,and extreme temperatures and watershed conditions are little analyzed.In this study,we collected gauged river flow and meteorological data time series from 1916 to 2015 and 1941 to 2015 across the contiguous United States(CONUS)for 188 catchments to investigate the temporal trends and spatial features of runoff changes at multi-time scales.We also analyzed the relationships between runoff changes and climatic factors.Median descriptive statistics and Budyko coupled climate elasticity methods were used to calculate runoff elasticity in each time scale.The original Mann-Kendall trend test was used to test their trend significance in four time-scale(11,20,40,and 60 a),respectively.The results show that the trend of runoff changes is more significant in high time scales;total changes are heterogeneous over CONUS.After the 1970s,increases of up to 27%decade-1 were mainly concentrated in the mid-northern regions.Maximum temperature and catchment characteristics are vital factors for runoff alteration;runoff changes are independent of rainfall,and wet regions tend to have lower changes.These findings could help develop better regional water resource planning and management.
基金Key Laboratory of Spinal Degenerative Diseases,Xianyang City(Project No.:L2023-CXNL-CXPT-ZDSYS-010)Key Technology Innovation Team Project for Minimally Invasive Spinal Surgery,Xianyang City(Grant No.:L2022CXNLTD002)University-level Scientific Research Project,Shaanxi University of Traditional Chinese Medicine(Project No.:2020FS06).
文摘Objective:To investigate the diagnostic value of magnetic resonance imaging(MRI)in patients with Modic changes and endplate sclerosis of the lumbar spine.Methods:A total of 66 patients with lumbar spine diseases who underwent MRI and CT diagnostic examinations at the hospital from May 2024 to April 2025 were included in this study.The MRI findings of Modic changes were compared between Type I and Type II patients,and the presence or absence of endplate sclerosis signals and the HU value ratio on CT were analyzed.The pathological characteristics of Modic changes in Type I and Type II patients were observed.The imaging features of Modic changes in patients with lumbar spine diseases were analyzed.Results:Modic changes were present in 34 patients,with a total of 204 endplates evaluated,of which 74 were affected.MRI classification showed:Type I in 8 cases(10.81%),Type I/II mixed in 10 cases(13.51%),Type II in 51 cases(68.92%),and Type II/III mixed in 5 cases(6.76%).In CT reconstruction images,26 endplates with Modic changes on MRI showed sclerosis in the vertebral body,presenting high-density sclerotic features.These sclerotic areas did not exhibit distinct signal characteristics on MRI but pathologically demonstrated Type II Modic changes concurrently with fatty degeneration and sclerosis;In patients with Modic changes of Type I and Type II,regardless of the presence or absence of endplate sclerosis,the sagittal T1/T2 signal intensity ratio showed no statistically significant difference(P>0.05).However,the HU value ratio in Type II changes with sclerotic regions(2.74±0.61)was significantly higher than that in regions without sclerosis(1.16±0.23),with a statistically significant difference(P<0.05).Conclusion:CT reconstruction images of patients with lumbar Modic changes clearly demonstrate endplate sclerosis,a phenomenon closely associated with the bone marrow repair process.MRI has limited sensitivity for detecting sclerosis,potentially due to the following factors:first,differences in the radiographic characterization of endplate mineral content;second,the specific influence of different Modic types on signal intensity.This suggests that MRI classification should be combined with CT features for comprehensive interpretation.
基金National Natural Science Foundation of China,No.42371103Natural Science Basic Research Plan in Shaanxi Province of China,No.2023-JC-YB-229。
文摘Understanding the local ecological security status and its underlying drivers can be used as an effective reference for balancing ecosystem development with societal needs. This study assesses the ecological security of the Loess Plateau(LP) by integrating ecosystem health and ecosystem services, explores the varying impacts of ecosystem structure, quality, and services on ecological security index(ESI), and identifies the key driving factors of ESI using the Geodetector model. The results show that:(1) the average ESI indicates a relatively safe ecological status in LP with a significant increase in ESI observed in 50.21% of the region, largely due to the ecological restoration programs.(2) Natural factors predominantly influence ESI, although human factors play a significant role in the earthy-rocky mountain region and plateau wind-sand region.(3) The interactions between driving factors have a much greater impact on ESI than any single factor, with the interactions between precipitation and human factors being the most influential combination. This study provides a novel perspective on assessing ecological security in LP. We recommend that future ecological restoration efforts should consider the varying roles of ecosystem structure, quality, and services in ESI while tailoring strategies to the primary driving factors based on local conditions.
基金the 2023 Open Project of the Kazakhstan Research Center at YiIi Normal University,Study on National Language Education Policy in Kazakhstan Under the Belt and Road Initiative(No.2023HSKSTYJYB007).
文摘Language policies are of great significance to a nation’s stability,unity,and development.Uzbekistan’s language policies have reflected the political,economic,and cultural dynamics of different periods throughout historical changes,influencing social structures and ethnic relations.This paper summarizes the characteristics of Uzbekistan’s language policies in different eras:During the Tsarist Russian period,the Russification of language policies hindered the development of local languages;in the Soviet era,policies adopted a dual approach,promoting both Russian and prioritizing ethnic languages;after independence,Uzbekistan established Uzbek as the state language and emphasized foreign language education.The current language policy in Uzbekistan presents a complex landscape:While emphasizing the dominant role of the national language helps preserve its heritage,it may easily spark ethnic and political tensions;promoting pluralism and inclusivity brings benefits but faces challenges in balancing language statuses,resource allocation,management,and communication;modernization efforts encounter difficulties in standardizing dialects and foreign loanwords;and in international exchanges,there is a need to balance relations with global lingua francas.In conclusion,Uzbekistan’s language policies have undergone unique transformations and face numerous challenges.In-depth research is crucial for improving the country’s policies and enhancing China-Uzbekistan cooperation.Proactive measures are needed to address these challenges,ensuring the sustainability of language policies and fostering greater national prosperity.
文摘BACKGROUND Gastric bezoars are masses of indigestible material that accumulate in the stomach,causing nausea,abdominal pain,and vomiting.Persimmon bezoars(diospyrobezoars),which comprise tannins and fibers from persimmons,are relatively rare but may cause significant gastric complications,including gastric outlet obstruction or ileus.Although computed tomography(CT)is a useful ima-ging tool,diagnosing bezoars can be challenging because their density is similar to that of food debris and gastric content.CASE SUMMARY Here,we report the case of a 72-year-old woman with a persimmon bezoar that was diagnosed using serial CT imaging and confirmed by endoscopy.CT perfor-med over several months revealed changes in the internal structure and density of the bezoar,suggesting progressive hardening.The patient had a history of a par-tial gastrectomy and excessive persimmon consumption,both of which are risk factors for bezoar formation.Endoscopic fragmentation of the bezoar successfully resolved symptoms.CONCLUSION Gastric bezoars,particularly persimmon bezoars,present diagnostic challenges because of their variable imaging characteristics.Serial CT can document tem-poral changes in bezoar density,potentially reflecting changes in hardness.Early diagnosis and endoscopic treatment are essential for effective management,particularly in patients with predisposing factors.This case underscores the im-portance of considering bezoars in the differential diagnosis of gastric masses,and highlights the value of CT for monitoring changes in bezoar characteristics over time.
基金supported by the National Natural Science Foundation of China(82104138)the Zhejiang Provincial Natural Science Foundation of China(LY24H310003).
文摘Fear memory,a predictive and protective mechanism in potentially hostile environments,elicits defensive behavioral responses that have evolved to help organisms avoid harm and ensure survival.However,excessive fear memories may contribute to the onset of various psychological disorders,such as panic disorder,phobias,and post-traumatic stress disorder(PTSD).
文摘Transformations of the world unseen in a century are unfolding at a faster pace.Changes of the world,of our times,and of the historical trajectory are taking place in ways like never before.As the new round of technological revolution and industrial transformation advances,the international power structure and world order are undergoing tectonic realignments and constantly being reshaped.The protracted Ukraine crisis and the escalating Palestinian-Israeli conflict exemplify the intensification of major-power strategic rivalries and geopolitical conflicts.At the same time,non-traditional security issues are getting severe and more deeply intertwined with traditional security.Challenges such as climate change,cybersecurity,energy security,and food security are becoming critical global issues which confront humanity with unprecedented threats and herald a new era of instability and transformation for the world’s development.
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.
文摘This study analyzed ambient seismic noise using the MSNoise package to monitor temporal changes in the underground seismic wave velocity in Mining Area 6 of the Dongtan Coal Mine in China.The data was recorded continuously over 76 days by 7 three-component stations and 10 single-component microseismic stations deployed in Dongtan Coal Mine,with station spacing ranging from 0.1 km to approximately 3 km.Using the causal and non-causal components of the Z-component cross-correlation function,along with moving-window cross-spectrum analysis and cumulative calculations with a 5-day window overlay,stable seismic velocity changes were obtained in the frequency band of 0.1 to 2 Hz.We found a correlation between the timing of average velocity changes and seismic events caused by underground mining processes.In particular,when the relative seismic velocity increased by 0.23%,larger energy minequakes typically occurred.This study shows that ambient noise correlation has great potential for predicting minequakes,guiding pressure-relief production,and providing warnings about the impact of overburden pressure.
基金The National Natural Science Foundation of China under contract Nos 42376256,42230405,and 41576020.
文摘The Antarctic Slope Current(ASC)links the processes occurring in the coast area with the global ocean by modulating the flow across the continental slope,which influences global overturning circulation and the mass balance of the Antarctic ice shelves.This paper aims to explore the effects of wind and buoyancy fluxes on the long-term changes in the ASC using observation and reanalysis datasets.From 1993 to 2022,the ASC accelerated in all seasons,particularly in austral autumn,and was accompanied with the advancement of the strong flow.The positive buoyancy flux anomaly generates a low-density anomaly,which is accumulated by the prevailing surface easterly,maintaining a sharp density front along the continental slope.The heat flux intensifies the positive trend of buoyancy flux in summer and autumn,increasing the input of the lighter density anomaly into the ocean and advancing the strong flow of ASC.Compared with the annual mean,the additional acceleration of the ASC in autumn is mainly due to the contribution of the barotropic component,which could be explained by the local momentum input from the weakly enhanced local surface wind.The acceleration of the ASC is primarily driven by the positive trend of the buoyancy flux,while the influence of the wind on its seasonal variability becomes more significant due to the contribution of the local surface wind in autumn.
基金financially supported by the National Key Research and Development Program of China(No.2023YFB3809101)the National Natural Science Foundation of China(No.U23A20128)the Chongqing Science and Technology Commission of China(CSTC2024YCJHBGZXM0041).
文摘Magnesium-based hydrogen storage materials are promising candidates for hydrogen storage due to their high storage density and environmentally friendly properties.However,the high dehydrogenation enthalpy change(approximately 75 kJ/mol H_(2))and high dehydrogenation temperature(573 K at 0.1 MPa)of MgH_(2),limits the engineering application of Mg/MgH_(2) as a hydrogen storage material.This work reviews the prediction models and methods of enthalpy changes for hydriding/dehydriding(H/D)reactions in order to find out the ideas and ways to reduce them.The mechanism behind the improvement methods mainly includes two aspects,weakening Mg-H bond and compensating heat of reaction.Proceed from this,the experimental methods and enthalpy data as well as calculated values of enthalpy changes were compared systematically.Elements such as Ti,Nb,V,etc.,with a small electronegativity difference compared to Mg,can reduce the hydrogenation and dehydrogenation enthalpy changes by forming strong Metal-H or Metal-Mg bonds.In addition,this review concludes with an outlook on the remaining challenge issues and prospects.
基金supported by the National Natural Science Foundation of China(Grant Nos.U2039203 and 42130306).
文摘On February 6,2023,the Türkiye Earthquake Doublet,consisting of two major earthquakes with magnitudes of M_(W)7.8 and M_(W)7.5,respectively,occurred within 9 h and devastated the Kahramanmaraşprovince in southwest Turkey.The geodynamic background of this area is exceedingly complicated owing to the combined action of the Anatolian Plate and the neighboring Eurasian,African,and Arabian plates,which contain many faults,the most prominent of which is the East Anatolian Fault Zone(EAFZ).These two earthquakes occurred on the Pazarcık Segment(PAZ.S)of the EAFZ and theÇardak Fault(CAR.F).The investigation of co-seismic changes in the velocity structure of the subterranean medium inside the focus area is critical for our understanding of earthquake ruptures.We chose 51572 travel times before the earthquake doublet from January 1,2014,to February 5,2023,and 88371 travel times after the earthquakes from February 6 to March 5,2023,and utilized time-lapse tomography to derive the co-seismic changes in P-wave velocity.The results demonstrated that the P-wave velocity decreased around the center zone,with considerable surface displacement from the two earthquakes caused by rock breakup and stress release.The P-wave velocity increased in two areas:east of the Pazarcik Earthquake,where the Bozova Fault is located,and west of the Elbistan Earthquake.We believe that these two locations are compression zones generated by the strike-slip surface displacement.Similarly,the decrease in velocity in the areas adjacent to the Malatya Fault(MAL.F)and between the Amanos Segment(AM.S)of the EAFZ and the Savur Fault(SA.F)shows that these two locations were exposed to tension as a result of the co-seismic horizontal displacement on the surface.This study showed that in addition to the area close to the epicenter,the large earthquake can affect the velocity structure of faults far away from the main shock.
基金supported by a research grant from the Hoyu Science Foundation in 2023.
文摘This study examined the positive changes that water-based nail treatments can bring to emotions and behavior in children who do not attend school and use a place for school-refusing children.Children who do not attend school and use a place for school-refusing children were given water-based nail treatments about once a week for three months.In addition,the parents of these children were asked to respond to questions about their children’s daily activities.The results showed that natural communication through nail treatments significantly increased positive emotions.However,continued nail treatments did not reduce the children’s problem behaviors.Some children returned to school,while others continued not attending school.Increased frequency of visits and number of treatments confirmed the promotion of communication.It was suggested that building positive relationships with family and supporters is important for achieving sustained effects from nail treatments.This study showed that nail treatments are a useful tool for promoting positive emotions,self-acceptance,and social skills,and may contribute to the emotional growth and social interest of children who do not attend school.
基金General Program of Natural Science Foundation of Xinjiang Uygur Autonomous Region(2022D01A275)Project of Inner Mongolia M-Grass Ecology and Environment(Group)Co.,Ltd.(2022-NFGA-004).
文摘[Objectives] To analyze the dynamic changes of maximum vegetation coverage in Ili River Basin from 2006 to 2020,and to explore the vegetation change and its influencing factors in the forest-grassland ecotone of Ili region.[Methods] The pixel dichotomy model was used to process the MODIS data and analyze the change of vegetation coverage in the Ili River Basin from 2006 to 2020.[Results] (i)The vegetation coverage in the Ili River Basin increases gradually from west to east,and fluctuates greatly between years.(ii)By monitoring the change rate of the maximum vegetation coverage,it is found that the vegetation coverage of the basin has experienced a process of first decline and then recovery in the past 15 years.(iii)In spatial distribution,vegetation coverage has improved in some regions,while it has deteriorated in others,which may be related to regional climate change and human activities.[Conclusions] The vegetation coverage in the Ili River Basin showed significant spatial and temporal differences during the study period,and its changes were affected by both natural and human factors.
基金supported by the Science and Technology Program of Fujian Province,China(No.2023R1014002)the National Natural Science Foundation of China(No.41471390).
文摘The toxicity of PM_(2.5)does not necessarily change synchronously with its mass concentration.In this study,the chemical composition(carbonaceous species,water-soluble ions,and metals)and oxidative potential(dithiothreitol assay,DTT)of PM_(2.5)were investigated in 2017/2018 and 2022 in Xiamen,China.The decrease rate of volume-normalized DTT(DTTv)(38%)was lower than that of PM_(2.5)(55%)between the two sampling periods.However,the mass-normalized DTT(DTTm)increased by 44%.Clear seasonal patterns with higher levels in winter were found for PM_(2.5),most chemical constituents and DTTv but not for DTTm.The large decrease in DTT activity(84%−92%)after the addition of EDTA suggested that watersoluble metals were the main contributors to DTT in Xiamen.The increased gap between the reconstructed and measured DTTv and the stronger correlations between the reconstructed/measured DTT ratio and carbonaceous species in 2022were observed.The decrease rates of the hazard index(32.5%)and lifetime cancer risk(9.1%)differed from those of PM_(2.5)and DTTv due to their different main contributors.The PMF-MLR model showed that the contributions(nmol/(min·m^(3)))of vehicle emission,coal+biomass burning,ship emission and secondary aerosol to DTTv in 2022 decreased by 63.0%,65.2%,66.5%,and 22.2%,respectively,compared to those in 2017/2018,which was consistent with the emission reduction of vehicle exhaust and coal consumption,the adoption of low-sulfur fuel oil used on board ships and the reduced production of WSOC.However,the contributions of dust+sea salt and industrial emission increased.
文摘Gas-bearing shales have become a major source of future natural gas production worldwide.It has become increasingly urgent to develop a reliable prediction model and corresponding workflow for identifying shale gas sweet spots.The formation of gas-bearing shales is closely linked to relative sealevel changes,providing an important approach to predicting sweet spots in the Wufeng-Longmaxi shale in the southern Sichuan Basin,China.Three types of marine shale gas sweet spots are identified in the shale based on their formation stages combined with relative sea-level changes:early,middle,and late transgression types.This study develops a prediction model and workflow for identifying shale gas sweet spots by analyzing relative sea-level changes and facies sequences.Predicting shale gas sweet spots in an explored block using this model and workflow can provide a valuable guide for well design and hydraulic fracturing,significantly enhancing the efficiency of shale gas exploration and development.Notably,the new prediction model and workflow can be utilized for the rapid evaluation of the potential for shale gas development in new shale gas blocks or those with low exploratory maturity.
