Mountain ecosystems offer natural gradients for exploring biodiversity patterns;however,the elevational patterns of plant species and phylogenetic diversity in the eastern Pamir Plateau remain poorly understood.As a b...Mountain ecosystems offer natural gradients for exploring biodiversity patterns;however,the elevational patterns of plant species and phylogenetic diversity in the eastern Pamir Plateau remain poorly understood.As a biogeographical junction of the Central Asian mountain ranges,the eastern Pamir Plateau in China is geographically connected to the main part of the Pamir Plateau in Tajikistan,resulting in significant climatic and topographical heterogeneity and unique regional vegetation communities.In this study,we established 5 elevational transects and 91 plots (1500–4870 m) in the eastern Pamir Plateau to investigate the patterns and environmental drivers of plant diversity at both regional and local spatial scales.We examined diversity patterns and community composition using regression models and community structure analysis and quantified the relative importance of environmental factors using a random forest model.The results showed a distinct differentiation along elevation gradients,with overall plant diversity,herbaceous plant diversity,and phylogenetic diversity index increasing with elevation,whereas woody plant diversity declined.The phylogenetic structure indices (including net relatedness index and nearest taxon index) exhibited heterogeneous elevational responses,indicating that community assembly was jointly driven by environmental filtering and niche differentiation.Soil nutrients,water availability,and temperature were the primary environmental drivers,with soil factors predominantly influencing herbaceous plant diversity,while climatic variables dominated woody plant diversity.These findings demonstrate that plant diversity along elevational gradients of the eastern Pamir Plateau exhibits the characteristic patterns of a unique arid mountain ecosystem,where enhanced soil fertility and moderate moisture at higher elevations partly offset energy limitations,thereby maintaining plant diversity through functional convergence of closely related lineages.This pattern of biodiversity maintenance contrasts with the divergence-driven community assembly processes commonly observed in humid mountain systems.Overall,this study contributes to a better understanding of biodiversity maintenance in the eastern Pamir Plateau.Given its geographical continuity with the Pamir Plateau in Tajikistan,our findings can provide a basis for alpine conservation efforts across arid Central Asia.展开更多
The carbon cycle stands as a cornerstone among the Earth's material cycles,carrying profound implications for global climate dynamics and humanity's sustenance and advancement.Additionally,nitrogen,as a vital ...The carbon cycle stands as a cornerstone among the Earth's material cycles,carrying profound implications for global climate dynamics and humanity's sustenance and advancement.Additionally,nitrogen,as a vital nutrient element,plays a pivotal role in biogeochemical processes,exerting significant influence on the ecological environment within watersheds.In this study,an analysis of the carbon(C)and nitrogen(N)components in the river water of 12 alpine basins on the eastern margin of the Tibetan Plateau(TP)reveals that the average dissolved organic carbon(DOC)concentration in the river water is 0.76±0.67 mg/L,indicating a lower level compared to the global river average organic carbon content.Specifically,the average DOC concentrations were 0.42±0.22 and 1.56±0.68 mg/L in the glacial and non-glacial basins,respectively.The average dissolved inorganic carbon(DIC)concentration in the eastern TP is 27.04±20.19 mg/L,with the lowest DIC observed at Dagu Glacier and the highest at Daxia River.Furthermore,the average dissolved total carbon(DTC)concentration in glacier river water was 18.87±12.65 mg/L,contrasting with 48.23±21.07 mg/L in non-glacial basins.The mean concentration of total nitrogen(TN)in the eastern TP averaged 0.97±0.54 mg/L,with the glacial basin registering 1.01±0.47 mg/L and the non-glacial basin at 0.89±0.70 mg/L.Evaluating the release fluxes of carbon and nitrogen across 12 river basins revealed a range of DTC emission fluxes from 0.32×10^(9)to 31.02×10^(9)g·C/a,with inorganic carbon comprising 71.0%to 99.5%.Consequently,the carbon emission flux for seven glacier basins totaled 15.91×10^(9)g·C/a,while for the five non-glacial river basins,it reached 87.37×10^(9)g·C/a.The total TN release fluxes across 12 small river basins amounted to 2.46×10^(9)g·N/a,with 0.84×10^(9)g·N/a released in glacial basins and 1.62×10^(9)g·N/a in the nonglacial basin.This study elucidates the spatial distribution and transport mechanisms of carbon and nitrogen elements within the glacial and downstream non-glacial basins,offering valuable insights into the biogeochemical cycles of carbon and nitrogen in the eastern Tibetan Plateau.展开更多
Based on reanalysis data and CMIP6 simulations,this study investigates the distinct responses of the cross-equatorial flows(CEFs)over the Maritime Continent(MC)under the simultaneous summer condition of two types of E...Based on reanalysis data and CMIP6 simulations,this study investigates the distinct responses of the cross-equatorial flows(CEFs)over the Maritime Continent(MC)under the simultaneous summer condition of two types of ENSO:central Pacific(CP)and eastern Pacific(EP).Results indicate that CP ENSO tends to exert stronger impacts on CEF.In CP ENSO years,significant lower-level southerly anomalies can be observed across all CEF branches adjacent to MC,accompanied by broader and deeper upper-level northerly anomalies,indicating a well-organized strengthening of both upper-and lowerlevel CEFs.In contrast,CEF anomalies in EP ENSO years tend to be weaker,with significant meridional wind anomalies confined to the east of MC.The disparities in the CEF responses can be elucidated from the perspective of convection over MC,a crucial factor in triggering CEF.In CP ENSO years,westward-leaning sea surface temperature(SST)anomalies result in a distinct cooling in MC and suppressed convection above,driving pronounced CEF anomalies.Conversely,the absence of such organized SST cooling during EP ENSO results in weaker convective forcing and subdued CEF responses.Furthermore,historical simulations from 48 CMIP6 models are utilized to validate the observational findings.Results show that model simulations can successfully reproduce the stronger impacts of CP ENSO,with a remarkable intermodel consistency.This research contributes toward a comprehensive understanding of the diversity in the relationship between CEF and ENSO types,and has implications for seasonal forecasting of CEF variability.展开更多
This study examines a 1.32 m thick sediment sequence from the Cunge sag pond in the Litang Basin,eastern Tibetan Plateau,to assess the seismicity of the Litang fault during the Holocene.High-resolution geochemical,gra...This study examines a 1.32 m thick sediment sequence from the Cunge sag pond in the Litang Basin,eastern Tibetan Plateau,to assess the seismicity of the Litang fault during the Holocene.High-resolution geochemical,grain size,magnetic susceptibility,and total organic carbon indicators are employed to obtain a continuous record of changes in elemental,physical,and biological properties within the profile to identify seismic events.The seismic event layer generally comprises two sedimentary rhythms:a lower coarse sand layer and an upper fine silt-clay layer.These layers represent rapid deposition associated with fault activity(Earthquake A)and slower deposition during calm periods or earthquake recurrence intervals(Seismic interval A).Through six^(14)C dating,five seismic events have been identified in the Cunge sag pond section:E1(before 3955 a B.P.),E2(3713-3703 a B.P.),E3(3492-3392 a B.P.),E4(2031-1894 a B.P.),and E5(1384-1321 a B.P.).E1-E4 had shown a good consistency with the paleo-earthquake recorded by the trench,and whereas E5 is a newly identified seismic event,further improving the continuous earthquake sequence of the Litang fault.Based on existing trench data and the seismic event record from the Cunge sag pond,a total of 11 paleo-earthquakes are identified along the Litang fault since the Holocene.The paleo-earthquake activity of the Litang fault exhibits a clustered pattern,with recurrence intervals of both long periods(1000 a)and short periods(500 a).Since 5000 a,the interval between strong earthquake recurrences gradually decreases,indicating an increasing risk of strong earthquakes along the Litang fault.This study presents a continuous record of paleo-earthquakes along the Litang fault,eastern Tibetan Plateau,and can enhance the understanding of regional seismic activity.展开更多
During the winter of 2023/24,three distinct snowfall events occurred in eastern China,significantly impacting agriculture and transportation.The ability to provide subseasonal predictions with lead times beyond the we...During the winter of 2023/24,three distinct snowfall events occurred in eastern China,significantly impacting agriculture and transportation.The ability to provide subseasonal predictions with lead times beyond the weather timescale(longer than one week)is essential for effective disaster prevention and mitigation.Here,we assess the prediction skills of three subseasonal to seasonal(S2S)models from the S2S Prediction project regarding the three snowfall processes during the 2023/24 winter season,and identify the key sources of predictability for such events occurring over eastern China.The surface air temperature(SAT)and precipitation distribution for the three snowfall processes were successfully reproduced up to a lead time of 10–15 and 10 days,respectively.Since the skill in predicting snowfall is reliant on both SAT and precipitation predictions,all three S2S models therefore failed to predict the three snowfall processes beyond the weather timescale.The capacity in capturing Eurasian midlatitude transient Rossby waves and tropical convection anomalies determines the ability of the models to predict snowfall;inaccuracies in modeling these circulation systems result in an underestimation of SAT and precipitation anomalies beyond 15 and 10 days,respectively.Singular value decomposition analysis based on winter seasons from 1991/92 to 2023/24 further identified the coupling modes that exist between Eurasian midlatitude Rossby waves and SAT over eastern China,as well as between tropical convection and precipitation over the same region.These findings suggest that the configurations of tropical and extratropical signals provide universal subseasonal predictability sources for winter snowfall over eastern China.展开更多
Ecosystems along the eastern margin of the Qinghai-Tibet Plateau(EQTP)are highly fragile and extremely sensitive to climate change and human disturbances.To quantitatively assess climate-induced ecosystem responses,th...Ecosystems along the eastern margin of the Qinghai-Tibet Plateau(EQTP)are highly fragile and extremely sensitive to climate change and human disturbances.To quantitatively assess climate-induced ecosystem responses,this study proposes a Climate-Induced Productivity Index(CIPI)based on the Super Slack-Based Measure(Super-SBM)model using remote sensing data from 2001 to 2020.The results reveal persistently low CIPI values(0.47-0.53)across major ecosystem types,indicating widespread vulnerability to climatic variability.Among these ecosystems,forests exhibit the highest CIPI(0.55),followed by shrublands(0.54),croplands(0.53),grasslands(0.51),and barelands(0.43).The Theil index analysis further demonstrates significant intra-group disparities,suggesting that extreme climatic events amplify CIPI heterogeneity.Moreover,the dominant environmental drivers differ among ecosystem types:the Palmer Drought Severity Index(PDSI)primarily constrains grassland productivity,solar radiation(SRAD)strongly influences shrub and cropland systems,whereas subsurface factors exert greater control in forested regions.This study provides a quantitative framework for evaluating climate-ecosystem interactions and offers a scientific basis for long-term ecological monitoring and security planning across the EQTP.展开更多
Background:That Central and Eastern Europe and Central Asia(CEECA)experienced a major mortality crisis in the 1990s is a well-established finding,with most analyses focusing on singular causes like alcohol-related dea...Background:That Central and Eastern Europe and Central Asia(CEECA)experienced a major mortality crisis in the 1990s is a well-established finding,with most analyses focusing on singular causes like alcohol-related deaths.However,the utility of the integrated“deaths of despair”framework,which views alcohol,drug,and suicide deaths as a unified socio-economic phenomenon,remains under-explored in this context.Crucially,the long-term evolution of the composition of despair within the region remains a largely unexplored area of inquiry.Therefore,this study aims to analyze the long-term trends,changing composition,and regional heterogeneity of deaths from despair in the CEECA region from 1980 to 2021.Methods:Using 2021 Global Burden of Disease(GBD)data(1980–2021),we analyzed deaths of despair mortality trends in 29 CEECA countries.We employed Joinpoint regression to identify significant trend changes and conducted stratified analyses by cause,gender,and age group.Results:The CEECA deaths of despair crisis began as an alcohol and suicide driven phenomenon concentrated in middle-aged men(50–74 years)during the 1990s,with mortality rates for alcohol use disorders and self-harm surging annually by 30.35%(p=0.002)and 13.44%(p=0.001),respectively,between 1991 and 1994.It has since evolved,marked by a contrasting and emerging threat in the 21st century:a rising proportion of drug-related deaths among the younger(15–49 years)male cohort,where the share of drug use disorders increased from 6.9%in 2000 to 11.8%in 2008.Conclusion:The deaths of despair crisis in the CEECA region is not a past event but an ongoing,evolving phenomenon.Its changing nature demands a shift in public health focus from solely historical drivers to new,generation-specific threats,particularly the rise of drug-related despair among youth.展开更多
Knowledge of the seismogenic environment of fault zones is critical for understanding the processes and mechanisms of large earthquakes.We conducted a rock magnetic study of the fault rocks and protoliths to investiga...Knowledge of the seismogenic environment of fault zones is critical for understanding the processes and mechanisms of large earthquakes.We conducted a rock magnetic study of the fault rocks and protoliths to investigate the seismogenic environment of earthquakes in the Motuo fault zone,in the eastern Himalayan syntaxis.The results indicate that magnetite is the principal magnetic carrier in the fault rocks and protolith,while the protolith has a higher content of paramagnetic minerals than the fault rocks.The fault rocks are characterized by a high magnetic susceptibility relative to the protolith in the Motuo fault zone.This is likely due to the thermal alteration of paramagnetic minerals to magnetite caused by coseismic frictional heating with concomitant hydrothermal fluid circulation.The high magnetic susceptibility of the fault rocks and neoformed magnetite indicate that large earthquakes with frictional heating temperatures>500℃have occurred in the Motuo fault zone in the past,and that the fault maintained an oxidizing environment with weak fluid action during these earthquakes.Our results reveal the seismogenic environment of the Motuo fault zone,and they are potentially important for the evaluation of the regional stability in the eastern Himalayan syntaxis.展开更多
Objectives:Nurses working in critical care units may encounter substantial work-related strain,and elevated levels of stress can lead to burnout,ultimately impacting both the quality of nursing care and their overall ...Objectives:Nurses working in critical care units may encounter substantial work-related strain,and elevated levels of stress can lead to burnout,ultimately impacting both the quality of nursing care and their overall working experience.This study aimed to assess job burnout and determine the factors that contribute to it among critical care nurses in the Eastern Province of Saudi Arabia.Methods:This study employed a descriptive,exploratory,cross-sectional research design.A total of 220 nurses employed in the critical care units of 5 private hospitals in the eastern region were selected for participation in this study using a convenience sample method.An electronic survey was distributed to critical care nurses in the Eastern Province who satisfied the specified inclusion criteria.The job burnout questionnaire utilized in this study was derived from previously conducted research,which has been established as a reliable and valid survey instrument.The process of data analysis was conducted utilizing the SPSS program.The scientific research conducted on human subjects adhered rigorously to all ethical considerations.Results:The highest percentage of nurses at the critical care units reported experiencing moderate levels of job burnout.Nurses exhibiting greater levels of professional experience demonstrated a statistically significant reduction in overall burnout scores when compared to their less experienced counterparts.Furthermore,within the realm of sociodemographic factors,it was found that the only significant independent predictor for job burnout was the level of experience among critical care nurses.Conclusions:The prevalence of burnout among nurses in critical care settings was found to be significant,with most participants reporting moderate levels of burnout which can yield significant ramifications for nurses and healthcare professionals.Consequently,healthcare organizations must accord primacy to the welfare of their staff and adopt proactive strategies to mitigate job burnout.展开更多
Frequent glacier-related watershed geohazard chains are causing severe damage to life and infrastructure,reported consistently from the Eastern Himalayan Syntaxis.This paper presents a systematic method for researchin...Frequent glacier-related watershed geohazard chains are causing severe damage to life and infrastructure,reported consistently from the Eastern Himalayan Syntaxis.This paper presents a systematic method for researching geohazard,from regional to individual scale.The methodology includes the establishment of geological chain inventories,discrimination of geohazard chain modes,analyses of dynamics and dam breaches,and risk assessments.The following results were obtained:(1)In the downstream of Yarlung Zangbo River,175 sites were identified as high-risk for river blockage disasters,indicating the development of watershed geohazards.Five geohazard chain modes were summarized by incorporating geomorphological characteristics,historical events,landslide zoning,and materials.The risk areas of typical hazard were identified and assessed using InSAR data.(2)Glacier-related watershed geohazard chains are significantly different from traditional landslides.A detailed inversion analysis was conducted on the massive rock-ice avalanche in the Sedongpu gully in 2021.This particular event lasted roughly 300 seconds,with a maximum flow velocity of 77.2 m/s and a maximum flow height of 93 meters.By scrutinizing the dynamic processes and mechanical characteristics,mobility stages and phase transitions can be divided into four stages.(3)Watershed geohazard chains tend to block rivers.The peak breach discharge of the Yigong Landslide reached 12.4×10^(4) m^(3)/s,which is 36 times the volume of the seasonal flood discharge in the Yigong River.Megafloods caused by landslide dam breaches have significantly shaped the geomorphology.This study offers insights into disaster patterns and the multistaged movement characteristics of glacier-related watershed geohazard chains,providing a comprehensive method for investigations and assessments in glacial regions.展开更多
The Mekkam inlier is located 50 km southeast of the town of Taourirt,in northeastern Morocco.It offers a great opportunity for the study of Variscan magmatism in Morocco.This inlier is punctuated by small magmatic bod...The Mekkam inlier is located 50 km southeast of the town of Taourirt,in northeastern Morocco.It offers a great opportunity for the study of Variscan magmatism in Morocco.This inlier is punctuated by small magmatic bodies which we will characterize through a petrographic and geochemical study to situate this inlier in its geotectonic context.The petrographic study revealed the existence of three trends:acidic,intermediate,and basic,which are represented by facies ranging from granites to basanites,including andesites,rhyolites,trachytes,dacites,quartz microdiorites,Aplite and microgranites.All these facies have a mineralogical assemblage dominated by quartz,plagioclase,oligoclase,potassium feldspar,pyroxene,and biotite;the most abundant accessory minerals are zircon and apatite.Green hornblende is found in microdiorites and dacites.The geochemical analysis,conducted through the examination of major elements,trace elements,and rare earth elements,has uncovered the presence of two distinct magmatic series:a calc-alkaline series of the island arc type or active continental margin,and another alkaline series of syn-collision.Based on this combined data,we propose that the Mekkam sector represents a magmatic arc developed within a compressional tectonic regime located above a subduction zone,which was later followed by an intracontinental collision phase.展开更多
Eastern Myanmar is the key position linking between SW Yunnan and northern Thailand for better understanding of Tethyan evolution.However,the actual location and evolution of the Tethyan suture zone are still unclear ...Eastern Myanmar is the key position linking between SW Yunnan and northern Thailand for better understanding of Tethyan evolution.However,the actual location and evolution of the Tethyan suture zone are still unclear in eastern Myanmar.The present study focuses on the geochronological,geochemical and zircon Lu-Hf isotopic study on the plutonic rocks,including granite,diorite and gabbroic rocks,from the Tachileik area,eastern Myanmar.These plutonic rocks yielded zircon U-Pb weighted mean ages of ca.353–355 Ma,suggesting the Early Carboniferous emplacement.The Tachileik granites are high-K calc-alkaline,weakly peraluminous and have low P2O5 contents,which are typical features of I-type granites.They have positive zircon ε_(Hf)(t)values(+4.5−+7.4)with T_(DM2) ages of 981–825 Ma,indicating a juvenile mafic lower crust source.The Tachileik gabbros and diorites show high Al_(2)O_(3) contents and Mg#,but low TiO_(2) and K_(2)O contents,belonging to tholeiitic and calc-alkaline basalt series.They are characterized by enrichments in large ion lithophile elements(LILEs,e.g.,Rb,Ba and Sr),depletions in high field strength elements(HFSEs)and distinctly negative Nb and Ta anomalies,similar to the volcanic arc basalt.The zircon Hf isotopic(+4.7−+7.1)and whole-rock geochemical data imply that the Tachileik gabros and diorites probably resulted from partial melting of lithospheric mantle in the spinel stability field within an arc-related setting.The magmatic rocks can be grouped to the Late Devonian–Early Carboniferous magmatic rock and pyroclastic rock zone from SW Yunnan to northern Thailand based on their age and geochemical characters.The zone was formed in the post-collisional extension-related tectonic setting of the Proto-Tethys.This study provides important evidences for the evolution of the Proto-Tethys in Southwest Yunnan and Southeast Asia.展开更多
Background:This paper examines the frequently neglected healthcare relations between China and the Soviet Union during the 1920s and 1930s.It analyzes how Soviet influence impacted healthcare in Northeast China,the st...Background:This paper examines the frequently neglected healthcare relations between China and the Soviet Union during the 1920s and 1930s.It analyzes how Soviet influence impacted healthcare in Northeast China,the strategies employed by Soviet authorities to promote their medical principles,and the factors that contributed to the eventual failure of socialized medicine in China during the interwar period.Methods:The study employs a historical approach and literature review to analyze the Soviet influence on public health in Manchuria.It utilizes materials from Russian archives in Moscow and Khabarovsk,Russian periodicals in Harbin in the 1920s–1930s,and published materials from this period.Results:It is mainly reflected in four aspects:The Russian Labor Red Cross in Harbin,the Soviet Red Cross organization in Harbin,Soviet medicine in the Chinese Eastern Railway(1924–1929),and Soviet medicine in the CER and Harbin in 1929–1939.Conclusion:Despite various efforts,Soviet medicine struggled to gain prominence in the region due to unfavorable political and sociocultural conditions.The healthcare system established by the Soviets in the CER did not fully embody the ideal of free general medical care and faced opposition due to issues such as the lowered social status of doctors and restrictions on patient rights.Additionally,the rise of nationalism in China posed a significant challenge,requiring Soviet doctors to adapt their practices to align with Chinese interests after 1929.Overall,the difficulty in effectively integrating and promoting Soviet healthcare ideals in the region limited their influence and success.展开更多
The China Pavilion has consistently been the primary vehicle for China's participation in World Expos over the years.From the first China Pavilion at the 1876 Philadelphia Expo to the 2025 China Pavilion at the on...The China Pavilion has consistently been the primary vehicle for China's participation in World Expos over the years.From the first China Pavilion at the 1876 Philadelphia Expo to the 2025 China Pavilion at the ongoing Osaka Expo,nearly 150 years have passed.During this span,the China Pavilion at the Expos.展开更多
In the author list,the corresponding author indicator(*)was inadvertently omitted from HOU Zengqian’s name.This has now been corrected to:“HOU Zengqian¹,*”.The online version of this article was corrected.
In this article,there were errors in Table 2 and Fig.5a which are corrected as below.In Table 2,the row headed alkali granite is incorrect.It should be alkaline granite.In Fig.5[a]the word alkali feldspar granite is i...In this article,there were errors in Table 2 and Fig.5a which are corrected as below.In Table 2,the row headed alkali granite is incorrect.It should be alkaline granite.In Fig.5[a]the word alkali feldspar granite is incor-rect,but should be alkaline granite;the Fig.5 should have appeared as shown below.The original article has been corrected.展开更多
The aim of this article is to study and reveal the mineralogical composition of dune sands from the Bouarfa Figuiget region(eastern Morocco)and to find the potential source of these dune sands.The mineralogical study ...The aim of this article is to study and reveal the mineralogical composition of dune sands from the Bouarfa Figuiget region(eastern Morocco)and to find the potential source of these dune sands.The mineralogical study was made by combining field studies to collect samples and determine the facies of the surrounding area with labortory studies,including geochemical analysis(DRX analysis),morphoscopic study of the sands under a binocular magnifying glass according to the fractions making up these sands,heavy mineral extraction and analysis under a microscope,and calcimetric analysis.The results revealed two main categories of minerals in sandy deposits:light and heavy minerals.These include quartz,plagioclase feldspar,calcite platelets,and fragments of greyish,greenish,and whitish rock.Quartz was the dominant mineral.Heavy minerals include dark(opaque)minerals such as garnet,tourmaline,epidote,zircon,rutile,and rock fragments.This composition is the result of erosion,transport,and deposition processes in the crystalline sandstone and sedimentary formations of the eastern High Atlas,which feed the study area via aeolian pathways,including winds from ERG CHBI.The quartz grains in the dune sands of the eastern region,accumulated by wind action,are mainly round,matte grains of aeolian origin.The mineral associations observed show the presence of two types of sandy deposits:(1)Sand dominated by matte,round quartz grains(fraction 225μm),associated with accessory minerals(garnet,tourmaline,zircon,rutile,kyanite,and epidote),oxides(magnetite and ilmenite),and rock fragments of mixed mineral,crystalline,and sedimentary origin.(2)Totally dominant matte round quartz sand associated with iron oxides and a few rock fragments(fractions 142μm,180μm and 357μm).Sand with fraction 225μm consists almost entirely of quartz(8%)with garnets and a few rock fragments.These results suggest that the variation in the composition of the dune sands in the study area depends on the nature of the granulometric fraction studied,and therefore on the variety of sources feeding the sands studied(Chott Tigri,crystalline and sedimentary formations of the Eastern High Atlas).展开更多
In recent years,torrential rain events caused by extratropical cyclones(ETCs)during the boreal midsummer(July-August)in Central and Eastern China have shown an increasing trend.For instence,in August 2024,two ETCs bro...In recent years,torrential rain events caused by extratropical cyclones(ETCs)during the boreal midsummer(July-August)in Central and Eastern China have shown an increasing trend.For instence,in August 2024,two ETCs brought large-scale heavy rainfall to North China,with daily precipitation exceeding 100 mm.Using reanalysis datasets and gridded precipitation data,the ETCs that affected Central and Eastern China during the boreal midsummer from 1981 to 2020 were objectively identified and tracked.ETCs causing precipitation were classified based on maximum daily precipitation,resulting in datasets for ETCs with torrential rain(daily precipitation exceeding 100 mm,referred to as ETC_R100)and heavy rain(daily precipitation exceeding 25 mm,referred to as ETC_R25).Comparative analysis can help highlight the characteristics of ETC_R100.This study compares the spatial distribution,movement paths,weather impacts,large-scale atmospheric circulation,and environmental conditions of these two types of precipitation-related ETCs.The following findings emerged:(1)ETC_R100 is driven by the combined forcing of upper-level troughs and warm-moist airflows at lower levels,exhibiting stronger thermal forcing than ETC_R25.(2)The moisture source for ETC_R100 are the Bay of Bengal and the Northwest Pacific,with moisture transported via the South China Sea.Compared to ETCs with nonextreme rainfall,ETC_R100 is characterized by greater atmospheric instability and better moisture conditions,resulting in higher precipitation intensity.(3)Regardless of the precipitation level,ETCs affected different regions but contributed significantly to precipitation in northern China,accounting for approximately 50%of the total precipitation.The results indicate that ETC_R100 differs significantly from ETCs with varying levels of precipitation in terms of statistical characteristics,weather impact,environmental conditions,and cyclogenesis conditions.展开更多
The phenomenon of'bamboo-like'thin interlayers developed in rock salt is one of the most prominent features of Paleogene salt-bearing strata in eastern China,where centimeter-thick rock salts appear separately...The phenomenon of'bamboo-like'thin interlayers developed in rock salt is one of the most prominent features of Paleogene salt-bearing strata in eastern China,where centimeter-thick rock salts appear separately,forming rhythmic units.At present,detailed analyses of these rhythms of rock salt are still limited,which directly affects the achievement of comprehensive and in-depth understanding of the developmental laws pertaining to this kind of saline lake.Therefore,we selected the typical rhythmic'bamboo-like'rock salts of the Shizhai Depression in Jiangsu Province as the research subject.Through careful observation of rock salts in hand samples and detailed petrographic and mineralogical analyses,we analyzed the hydrogen and oxygen isotopic compositions,homogenization temperatures and chemical compositions of individual fluid inclusions in halite crystals.Early-stage rhythmic deposition was a product of continental saline lake evolution in winter or spring,late-stage rhythmic deposition being the product of evolution in the summer.The seasonal evolution of the halite sequences was determined and two brine enrichment events were identified.In addition,the quiet saline lake environment with concentrated brine represented by rock salt was more likely to precipitate potassium.This study provides a new reference for the evolution of both Paleogene climate and saline lakes in eastern China.展开更多
基金supported by the National Key Research and Development Program of China (2024YFE0214200)the National Natural Science Foundation of China (42201072)。
文摘Mountain ecosystems offer natural gradients for exploring biodiversity patterns;however,the elevational patterns of plant species and phylogenetic diversity in the eastern Pamir Plateau remain poorly understood.As a biogeographical junction of the Central Asian mountain ranges,the eastern Pamir Plateau in China is geographically connected to the main part of the Pamir Plateau in Tajikistan,resulting in significant climatic and topographical heterogeneity and unique regional vegetation communities.In this study,we established 5 elevational transects and 91 plots (1500–4870 m) in the eastern Pamir Plateau to investigate the patterns and environmental drivers of plant diversity at both regional and local spatial scales.We examined diversity patterns and community composition using regression models and community structure analysis and quantified the relative importance of environmental factors using a random forest model.The results showed a distinct differentiation along elevation gradients,with overall plant diversity,herbaceous plant diversity,and phylogenetic diversity index increasing with elevation,whereas woody plant diversity declined.The phylogenetic structure indices (including net relatedness index and nearest taxon index) exhibited heterogeneous elevational responses,indicating that community assembly was jointly driven by environmental filtering and niche differentiation.Soil nutrients,water availability,and temperature were the primary environmental drivers,with soil factors predominantly influencing herbaceous plant diversity,while climatic variables dominated woody plant diversity.These findings demonstrate that plant diversity along elevational gradients of the eastern Pamir Plateau exhibits the characteristic patterns of a unique arid mountain ecosystem,where enhanced soil fertility and moderate moisture at higher elevations partly offset energy limitations,thereby maintaining plant diversity through functional convergence of closely related lineages.This pattern of biodiversity maintenance contrasts with the divergence-driven community assembly processes commonly observed in humid mountain systems.Overall,this study contributes to a better understanding of biodiversity maintenance in the eastern Pamir Plateau.Given its geographical continuity with the Pamir Plateau in Tajikistan,our findings can provide a basis for alpine conservation efforts across arid Central Asia.
基金supported by the National Natural Science Foundation of China(Nos.42371139,42201152)the Fundamental Research Funds for the Central Universities,China University of Geosciences(Wuhan)(No.CUG240629)+2 种基金the“CUG Scholar”Scientific Research Funds at China University of Geosciences(Wuhan)(No.2023092)the Gansu Province Natural Science Foundation Key Project(No.23JRRA858)CAS President's International Fellowship for Visiting Scientists(No.2024PVC003)。
文摘The carbon cycle stands as a cornerstone among the Earth's material cycles,carrying profound implications for global climate dynamics and humanity's sustenance and advancement.Additionally,nitrogen,as a vital nutrient element,plays a pivotal role in biogeochemical processes,exerting significant influence on the ecological environment within watersheds.In this study,an analysis of the carbon(C)and nitrogen(N)components in the river water of 12 alpine basins on the eastern margin of the Tibetan Plateau(TP)reveals that the average dissolved organic carbon(DOC)concentration in the river water is 0.76±0.67 mg/L,indicating a lower level compared to the global river average organic carbon content.Specifically,the average DOC concentrations were 0.42±0.22 and 1.56±0.68 mg/L in the glacial and non-glacial basins,respectively.The average dissolved inorganic carbon(DIC)concentration in the eastern TP is 27.04±20.19 mg/L,with the lowest DIC observed at Dagu Glacier and the highest at Daxia River.Furthermore,the average dissolved total carbon(DTC)concentration in glacier river water was 18.87±12.65 mg/L,contrasting with 48.23±21.07 mg/L in non-glacial basins.The mean concentration of total nitrogen(TN)in the eastern TP averaged 0.97±0.54 mg/L,with the glacial basin registering 1.01±0.47 mg/L and the non-glacial basin at 0.89±0.70 mg/L.Evaluating the release fluxes of carbon and nitrogen across 12 river basins revealed a range of DTC emission fluxes from 0.32×10^(9)to 31.02×10^(9)g·C/a,with inorganic carbon comprising 71.0%to 99.5%.Consequently,the carbon emission flux for seven glacier basins totaled 15.91×10^(9)g·C/a,while for the five non-glacial river basins,it reached 87.37×10^(9)g·C/a.The total TN release fluxes across 12 small river basins amounted to 2.46×10^(9)g·N/a,with 0.84×10^(9)g·N/a released in glacial basins and 1.62×10^(9)g·N/a in the nonglacial basin.This study elucidates the spatial distribution and transport mechanisms of carbon and nitrogen elements within the glacial and downstream non-glacial basins,offering valuable insights into the biogeochemical cycles of carbon and nitrogen in the eastern Tibetan Plateau.
基金supported by the National Natural Science Foundation of China(Grant No.42405029).
文摘Based on reanalysis data and CMIP6 simulations,this study investigates the distinct responses of the cross-equatorial flows(CEFs)over the Maritime Continent(MC)under the simultaneous summer condition of two types of ENSO:central Pacific(CP)and eastern Pacific(EP).Results indicate that CP ENSO tends to exert stronger impacts on CEF.In CP ENSO years,significant lower-level southerly anomalies can be observed across all CEF branches adjacent to MC,accompanied by broader and deeper upper-level northerly anomalies,indicating a well-organized strengthening of both upper-and lowerlevel CEFs.In contrast,CEF anomalies in EP ENSO years tend to be weaker,with significant meridional wind anomalies confined to the east of MC.The disparities in the CEF responses can be elucidated from the perspective of convection over MC,a crucial factor in triggering CEF.In CP ENSO years,westward-leaning sea surface temperature(SST)anomalies result in a distinct cooling in MC and suppressed convection above,driving pronounced CEF anomalies.Conversely,the absence of such organized SST cooling during EP ENSO results in weaker convective forcing and subdued CEF responses.Furthermore,historical simulations from 48 CMIP6 models are utilized to validate the observational findings.Results show that model simulations can successfully reproduce the stronger impacts of CP ENSO,with a remarkable intermodel consistency.This research contributes toward a comprehensive understanding of the diversity in the relationship between CEF and ENSO types,and has implications for seasonal forecasting of CEF variability.
基金supported by the National Natural Science Foundation of China(42202131 and 42177184).
文摘This study examines a 1.32 m thick sediment sequence from the Cunge sag pond in the Litang Basin,eastern Tibetan Plateau,to assess the seismicity of the Litang fault during the Holocene.High-resolution geochemical,grain size,magnetic susceptibility,and total organic carbon indicators are employed to obtain a continuous record of changes in elemental,physical,and biological properties within the profile to identify seismic events.The seismic event layer generally comprises two sedimentary rhythms:a lower coarse sand layer and an upper fine silt-clay layer.These layers represent rapid deposition associated with fault activity(Earthquake A)and slower deposition during calm periods or earthquake recurrence intervals(Seismic interval A).Through six^(14)C dating,five seismic events have been identified in the Cunge sag pond section:E1(before 3955 a B.P.),E2(3713-3703 a B.P.),E3(3492-3392 a B.P.),E4(2031-1894 a B.P.),and E5(1384-1321 a B.P.).E1-E4 had shown a good consistency with the paleo-earthquake recorded by the trench,and whereas E5 is a newly identified seismic event,further improving the continuous earthquake sequence of the Litang fault.Based on existing trench data and the seismic event record from the Cunge sag pond,a total of 11 paleo-earthquakes are identified along the Litang fault since the Holocene.The paleo-earthquake activity of the Litang fault exhibits a clustered pattern,with recurrence intervals of both long periods(1000 a)and short periods(500 a).Since 5000 a,the interval between strong earthquake recurrences gradually decreases,indicating an increasing risk of strong earthquakes along the Litang fault.This study presents a continuous record of paleo-earthquakes along the Litang fault,eastern Tibetan Plateau,and can enhance the understanding of regional seismic activity.
基金supported by the National Key R&D Program of China(Grant No.2022YFF0801702)the Natural Science Foundation of Jiangsu Province(Grant No.BK20250045&BK20231110)the China Meteorological Administration Innovation and Development Project(Grant No.CXFZ2025Q007).
文摘During the winter of 2023/24,three distinct snowfall events occurred in eastern China,significantly impacting agriculture and transportation.The ability to provide subseasonal predictions with lead times beyond the weather timescale(longer than one week)is essential for effective disaster prevention and mitigation.Here,we assess the prediction skills of three subseasonal to seasonal(S2S)models from the S2S Prediction project regarding the three snowfall processes during the 2023/24 winter season,and identify the key sources of predictability for such events occurring over eastern China.The surface air temperature(SAT)and precipitation distribution for the three snowfall processes were successfully reproduced up to a lead time of 10–15 and 10 days,respectively.Since the skill in predicting snowfall is reliant on both SAT and precipitation predictions,all three S2S models therefore failed to predict the three snowfall processes beyond the weather timescale.The capacity in capturing Eurasian midlatitude transient Rossby waves and tropical convection anomalies determines the ability of the models to predict snowfall;inaccuracies in modeling these circulation systems result in an underestimation of SAT and precipitation anomalies beyond 15 and 10 days,respectively.Singular value decomposition analysis based on winter seasons from 1991/92 to 2023/24 further identified the coupling modes that exist between Eurasian midlatitude Rossby waves and SAT over eastern China,as well as between tropical convection and precipitation over the same region.These findings suggest that the configurations of tropical and extratropical signals provide universal subseasonal predictability sources for winter snowfall over eastern China.
基金National Key R&D Program of China,No.2022YFF1302401National Natural Science Foundation of China,No.42271007。
文摘Ecosystems along the eastern margin of the Qinghai-Tibet Plateau(EQTP)are highly fragile and extremely sensitive to climate change and human disturbances.To quantitatively assess climate-induced ecosystem responses,this study proposes a Climate-Induced Productivity Index(CIPI)based on the Super Slack-Based Measure(Super-SBM)model using remote sensing data from 2001 to 2020.The results reveal persistently low CIPI values(0.47-0.53)across major ecosystem types,indicating widespread vulnerability to climatic variability.Among these ecosystems,forests exhibit the highest CIPI(0.55),followed by shrublands(0.54),croplands(0.53),grasslands(0.51),and barelands(0.43).The Theil index analysis further demonstrates significant intra-group disparities,suggesting that extreme climatic events amplify CIPI heterogeneity.Moreover,the dominant environmental drivers differ among ecosystem types:the Palmer Drought Severity Index(PDSI)primarily constrains grassland productivity,solar radiation(SRAD)strongly influences shrub and cropland systems,whereas subsurface factors exert greater control in forested regions.This study provides a quantitative framework for evaluating climate-ecosystem interactions and offers a scientific basis for long-term ecological monitoring and security planning across the EQTP.
基金supported by grants from the National Research Foundation of Korea(NRF)under the Ministry of Science and Information and Communication Technology(grant number:RS-2023-00249082)Korea University(grant number:K2225791).
文摘Background:That Central and Eastern Europe and Central Asia(CEECA)experienced a major mortality crisis in the 1990s is a well-established finding,with most analyses focusing on singular causes like alcohol-related deaths.However,the utility of the integrated“deaths of despair”framework,which views alcohol,drug,and suicide deaths as a unified socio-economic phenomenon,remains under-explored in this context.Crucially,the long-term evolution of the composition of despair within the region remains a largely unexplored area of inquiry.Therefore,this study aims to analyze the long-term trends,changing composition,and regional heterogeneity of deaths from despair in the CEECA region from 1980 to 2021.Methods:Using 2021 Global Burden of Disease(GBD)data(1980–2021),we analyzed deaths of despair mortality trends in 29 CEECA countries.We employed Joinpoint regression to identify significant trend changes and conducted stratified analyses by cause,gender,and age group.Results:The CEECA deaths of despair crisis began as an alcohol and suicide driven phenomenon concentrated in middle-aged men(50–74 years)during the 1990s,with mortality rates for alcohol use disorders and self-harm surging annually by 30.35%(p=0.002)and 13.44%(p=0.001),respectively,between 1991 and 1994.It has since evolved,marked by a contrasting and emerging threat in the 21st century:a rising proportion of drug-related deaths among the younger(15–49 years)male cohort,where the share of drug use disorders increased from 6.9%in 2000 to 11.8%in 2008.Conclusion:The deaths of despair crisis in the CEECA region is not a past event but an ongoing,evolving phenomenon.Its changing nature demands a shift in public health focus from solely historical drivers to new,generation-specific threats,particularly the rise of drug-related despair among youth.
基金supported by the Fundamental Research Funds of the Institute of Geomechanics(DZLXJK202401)the National Natural Science Foundation of China(42177172,U2244226,42172255)+1 种基金the China Geological Survey Project(DD20230538)Deep Earth Probe and Mineral Resources ExplorationNational Science and Technology Major Project(2024ZD1000500)。
文摘Knowledge of the seismogenic environment of fault zones is critical for understanding the processes and mechanisms of large earthquakes.We conducted a rock magnetic study of the fault rocks and protoliths to investigate the seismogenic environment of earthquakes in the Motuo fault zone,in the eastern Himalayan syntaxis.The results indicate that magnetite is the principal magnetic carrier in the fault rocks and protolith,while the protolith has a higher content of paramagnetic minerals than the fault rocks.The fault rocks are characterized by a high magnetic susceptibility relative to the protolith in the Motuo fault zone.This is likely due to the thermal alteration of paramagnetic minerals to magnetite caused by coseismic frictional heating with concomitant hydrothermal fluid circulation.The high magnetic susceptibility of the fault rocks and neoformed magnetite indicate that large earthquakes with frictional heating temperatures>500℃have occurred in the Motuo fault zone in the past,and that the fault maintained an oxidizing environment with weak fluid action during these earthquakes.Our results reveal the seismogenic environment of the Motuo fault zone,and they are potentially important for the evaluation of the regional stability in the eastern Himalayan syntaxis.
文摘Objectives:Nurses working in critical care units may encounter substantial work-related strain,and elevated levels of stress can lead to burnout,ultimately impacting both the quality of nursing care and their overall working experience.This study aimed to assess job burnout and determine the factors that contribute to it among critical care nurses in the Eastern Province of Saudi Arabia.Methods:This study employed a descriptive,exploratory,cross-sectional research design.A total of 220 nurses employed in the critical care units of 5 private hospitals in the eastern region were selected for participation in this study using a convenience sample method.An electronic survey was distributed to critical care nurses in the Eastern Province who satisfied the specified inclusion criteria.The job burnout questionnaire utilized in this study was derived from previously conducted research,which has been established as a reliable and valid survey instrument.The process of data analysis was conducted utilizing the SPSS program.The scientific research conducted on human subjects adhered rigorously to all ethical considerations.Results:The highest percentage of nurses at the critical care units reported experiencing moderate levels of job burnout.Nurses exhibiting greater levels of professional experience demonstrated a statistically significant reduction in overall burnout scores when compared to their less experienced counterparts.Furthermore,within the realm of sociodemographic factors,it was found that the only significant independent predictor for job burnout was the level of experience among critical care nurses.Conclusions:The prevalence of burnout among nurses in critical care settings was found to be significant,with most participants reporting moderate levels of burnout which can yield significant ramifications for nurses and healthcare professionals.Consequently,healthcare organizations must accord primacy to the welfare of their staff and adopt proactive strategies to mitigate job burnout.
基金supported by the National Natural Science Foundation of China(Nos.U2244227,U2244226,42177172)the National Key R&D Program of China(No.2022YFC3004301)China Geological Survey Project(No.DD20230538)。
文摘Frequent glacier-related watershed geohazard chains are causing severe damage to life and infrastructure,reported consistently from the Eastern Himalayan Syntaxis.This paper presents a systematic method for researching geohazard,from regional to individual scale.The methodology includes the establishment of geological chain inventories,discrimination of geohazard chain modes,analyses of dynamics and dam breaches,and risk assessments.The following results were obtained:(1)In the downstream of Yarlung Zangbo River,175 sites were identified as high-risk for river blockage disasters,indicating the development of watershed geohazards.Five geohazard chain modes were summarized by incorporating geomorphological characteristics,historical events,landslide zoning,and materials.The risk areas of typical hazard were identified and assessed using InSAR data.(2)Glacier-related watershed geohazard chains are significantly different from traditional landslides.A detailed inversion analysis was conducted on the massive rock-ice avalanche in the Sedongpu gully in 2021.This particular event lasted roughly 300 seconds,with a maximum flow velocity of 77.2 m/s and a maximum flow height of 93 meters.By scrutinizing the dynamic processes and mechanical characteristics,mobility stages and phase transitions can be divided into four stages.(3)Watershed geohazard chains tend to block rivers.The peak breach discharge of the Yigong Landslide reached 12.4×10^(4) m^(3)/s,which is 36 times the volume of the seasonal flood discharge in the Yigong River.Megafloods caused by landslide dam breaches have significantly shaped the geomorphology.This study offers insights into disaster patterns and the multistaged movement characteristics of glacier-related watershed geohazard chains,providing a comprehensive method for investigations and assessments in glacial regions.
文摘The Mekkam inlier is located 50 km southeast of the town of Taourirt,in northeastern Morocco.It offers a great opportunity for the study of Variscan magmatism in Morocco.This inlier is punctuated by small magmatic bodies which we will characterize through a petrographic and geochemical study to situate this inlier in its geotectonic context.The petrographic study revealed the existence of three trends:acidic,intermediate,and basic,which are represented by facies ranging from granites to basanites,including andesites,rhyolites,trachytes,dacites,quartz microdiorites,Aplite and microgranites.All these facies have a mineralogical assemblage dominated by quartz,plagioclase,oligoclase,potassium feldspar,pyroxene,and biotite;the most abundant accessory minerals are zircon and apatite.Green hornblende is found in microdiorites and dacites.The geochemical analysis,conducted through the examination of major elements,trace elements,and rare earth elements,has uncovered the presence of two distinct magmatic series:a calc-alkaline series of the island arc type or active continental margin,and another alkaline series of syn-collision.Based on this combined data,we propose that the Mekkam sector represents a magmatic arc developed within a compressional tectonic regime located above a subduction zone,which was later followed by an intracontinental collision phase.
基金supported by the National Natural Science Foundation of China(No.41672222)the State Key Laboratory of Geological Process and Mineral Resources,China University of Geosciences,Wuhan.
文摘Eastern Myanmar is the key position linking between SW Yunnan and northern Thailand for better understanding of Tethyan evolution.However,the actual location and evolution of the Tethyan suture zone are still unclear in eastern Myanmar.The present study focuses on the geochronological,geochemical and zircon Lu-Hf isotopic study on the plutonic rocks,including granite,diorite and gabbroic rocks,from the Tachileik area,eastern Myanmar.These plutonic rocks yielded zircon U-Pb weighted mean ages of ca.353–355 Ma,suggesting the Early Carboniferous emplacement.The Tachileik granites are high-K calc-alkaline,weakly peraluminous and have low P2O5 contents,which are typical features of I-type granites.They have positive zircon ε_(Hf)(t)values(+4.5−+7.4)with T_(DM2) ages of 981–825 Ma,indicating a juvenile mafic lower crust source.The Tachileik gabbros and diorites show high Al_(2)O_(3) contents and Mg#,but low TiO_(2) and K_(2)O contents,belonging to tholeiitic and calc-alkaline basalt series.They are characterized by enrichments in large ion lithophile elements(LILEs,e.g.,Rb,Ba and Sr),depletions in high field strength elements(HFSEs)and distinctly negative Nb and Ta anomalies,similar to the volcanic arc basalt.The zircon Hf isotopic(+4.7−+7.1)and whole-rock geochemical data imply that the Tachileik gabros and diorites probably resulted from partial melting of lithospheric mantle in the spinel stability field within an arc-related setting.The magmatic rocks can be grouped to the Late Devonian–Early Carboniferous magmatic rock and pyroclastic rock zone from SW Yunnan to northern Thailand based on their age and geochemical characters.The zone was formed in the post-collisional extension-related tectonic setting of the Proto-Tethys.This study provides important evidences for the evolution of the Proto-Tethys in Southwest Yunnan and Southeast Asia.
文摘Background:This paper examines the frequently neglected healthcare relations between China and the Soviet Union during the 1920s and 1930s.It analyzes how Soviet influence impacted healthcare in Northeast China,the strategies employed by Soviet authorities to promote their medical principles,and the factors that contributed to the eventual failure of socialized medicine in China during the interwar period.Methods:The study employs a historical approach and literature review to analyze the Soviet influence on public health in Manchuria.It utilizes materials from Russian archives in Moscow and Khabarovsk,Russian periodicals in Harbin in the 1920s–1930s,and published materials from this period.Results:It is mainly reflected in four aspects:The Russian Labor Red Cross in Harbin,the Soviet Red Cross organization in Harbin,Soviet medicine in the Chinese Eastern Railway(1924–1929),and Soviet medicine in the CER and Harbin in 1929–1939.Conclusion:Despite various efforts,Soviet medicine struggled to gain prominence in the region due to unfavorable political and sociocultural conditions.The healthcare system established by the Soviets in the CER did not fully embody the ideal of free general medical care and faced opposition due to issues such as the lowered social status of doctors and restrictions on patient rights.Additionally,the rise of nationalism in China posed a significant challenge,requiring Soviet doctors to adapt their practices to align with Chinese interests after 1929.Overall,the difficulty in effectively integrating and promoting Soviet healthcare ideals in the region limited their influence and success.
文摘The China Pavilion has consistently been the primary vehicle for China's participation in World Expos over the years.From the first China Pavilion at the 1876 Philadelphia Expo to the 2025 China Pavilion at the ongoing Osaka Expo,nearly 150 years have passed.During this span,the China Pavilion at the Expos.
文摘In the author list,the corresponding author indicator(*)was inadvertently omitted from HOU Zengqian’s name.This has now been corrected to:“HOU Zengqian¹,*”.The online version of this article was corrected.
文摘In this article,there were errors in Table 2 and Fig.5a which are corrected as below.In Table 2,the row headed alkali granite is incorrect.It should be alkaline granite.In Fig.5[a]the word alkali feldspar granite is incor-rect,but should be alkaline granite;the Fig.5 should have appeared as shown below.The original article has been corrected.
基金supported by the Académie Hassan Ⅱ des Sciences et Techniques(Rabat,Morocco)as part of the AP-2018 project.
文摘The aim of this article is to study and reveal the mineralogical composition of dune sands from the Bouarfa Figuiget region(eastern Morocco)and to find the potential source of these dune sands.The mineralogical study was made by combining field studies to collect samples and determine the facies of the surrounding area with labortory studies,including geochemical analysis(DRX analysis),morphoscopic study of the sands under a binocular magnifying glass according to the fractions making up these sands,heavy mineral extraction and analysis under a microscope,and calcimetric analysis.The results revealed two main categories of minerals in sandy deposits:light and heavy minerals.These include quartz,plagioclase feldspar,calcite platelets,and fragments of greyish,greenish,and whitish rock.Quartz was the dominant mineral.Heavy minerals include dark(opaque)minerals such as garnet,tourmaline,epidote,zircon,rutile,and rock fragments.This composition is the result of erosion,transport,and deposition processes in the crystalline sandstone and sedimentary formations of the eastern High Atlas,which feed the study area via aeolian pathways,including winds from ERG CHBI.The quartz grains in the dune sands of the eastern region,accumulated by wind action,are mainly round,matte grains of aeolian origin.The mineral associations observed show the presence of two types of sandy deposits:(1)Sand dominated by matte,round quartz grains(fraction 225μm),associated with accessory minerals(garnet,tourmaline,zircon,rutile,kyanite,and epidote),oxides(magnetite and ilmenite),and rock fragments of mixed mineral,crystalline,and sedimentary origin.(2)Totally dominant matte round quartz sand associated with iron oxides and a few rock fragments(fractions 142μm,180μm and 357μm).Sand with fraction 225μm consists almost entirely of quartz(8%)with garnets and a few rock fragments.These results suggest that the variation in the composition of the dune sands in the study area depends on the nature of the granulometric fraction studied,and therefore on the variety of sources feeding the sands studied(Chott Tigri,crystalline and sedimentary formations of the Eastern High Atlas).
基金National Natural Science Foundation of China(42375014,42088101,42030605)Joint Research Project for Meteorological Capacity Improvement(24NLTSZ010)Young Elite Scientists Sponsorship Program by BAST(BYESS2023205)。
文摘In recent years,torrential rain events caused by extratropical cyclones(ETCs)during the boreal midsummer(July-August)in Central and Eastern China have shown an increasing trend.For instence,in August 2024,two ETCs brought large-scale heavy rainfall to North China,with daily precipitation exceeding 100 mm.Using reanalysis datasets and gridded precipitation data,the ETCs that affected Central and Eastern China during the boreal midsummer from 1981 to 2020 were objectively identified and tracked.ETCs causing precipitation were classified based on maximum daily precipitation,resulting in datasets for ETCs with torrential rain(daily precipitation exceeding 100 mm,referred to as ETC_R100)and heavy rain(daily precipitation exceeding 25 mm,referred to as ETC_R25).Comparative analysis can help highlight the characteristics of ETC_R100.This study compares the spatial distribution,movement paths,weather impacts,large-scale atmospheric circulation,and environmental conditions of these two types of precipitation-related ETCs.The following findings emerged:(1)ETC_R100 is driven by the combined forcing of upper-level troughs and warm-moist airflows at lower levels,exhibiting stronger thermal forcing than ETC_R25.(2)The moisture source for ETC_R100 are the Bay of Bengal and the Northwest Pacific,with moisture transported via the South China Sea.Compared to ETCs with nonextreme rainfall,ETC_R100 is characterized by greater atmospheric instability and better moisture conditions,resulting in higher precipitation intensity.(3)Regardless of the precipitation level,ETCs affected different regions but contributed significantly to precipitation in northern China,accounting for approximately 50%of the total precipitation.The results indicate that ETC_R100 differs significantly from ETCs with varying levels of precipitation in terms of statistical characteristics,weather impact,environmental conditions,and cyclogenesis conditions.
基金supported by the Natural Science Foundation of Jiangxi Province,China(Grant No.20242BAB20130)the Basic Research Funds Program of the Chinese Academy of Geological Sciences(Grant No.YYWF201607)the National Natural Science Foundation of China(Grant No.41902064)。
文摘The phenomenon of'bamboo-like'thin interlayers developed in rock salt is one of the most prominent features of Paleogene salt-bearing strata in eastern China,where centimeter-thick rock salts appear separately,forming rhythmic units.At present,detailed analyses of these rhythms of rock salt are still limited,which directly affects the achievement of comprehensive and in-depth understanding of the developmental laws pertaining to this kind of saline lake.Therefore,we selected the typical rhythmic'bamboo-like'rock salts of the Shizhai Depression in Jiangsu Province as the research subject.Through careful observation of rock salts in hand samples and detailed petrographic and mineralogical analyses,we analyzed the hydrogen and oxygen isotopic compositions,homogenization temperatures and chemical compositions of individual fluid inclusions in halite crystals.Early-stage rhythmic deposition was a product of continental saline lake evolution in winter or spring,late-stage rhythmic deposition being the product of evolution in the summer.The seasonal evolution of the halite sequences was determined and two brine enrichment events were identified.In addition,the quiet saline lake environment with concentrated brine represented by rock salt was more likely to precipitate potassium.This study provides a new reference for the evolution of both Paleogene climate and saline lakes in eastern China.
