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
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
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
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
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 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
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
A prevailing theory suggests that volcanic eruptions triggered environmental changes,which compelled dinosaurs to migrate in search of new habitats.Compelling evidence for this hypothesis has now been discovered in th...A prevailing theory suggests that volcanic eruptions triggered environmental changes,which compelled dinosaurs to migrate in search of new habitats.Compelling evidence for this hypothesis has now been discovered in the Tunxi Basin of eastern China.During the Late Mesozoic,the subduction of the Pacific Plate beneath southeastern China led to multi-stage volcanic activity.The Tunxi Formation in the basin,the first reported Upper Jurassic volcanic unit in the eastern Jiangnan orogen.It overlies the stratum bearing the easternmost mamenchisaurids,which is the dominant Asian sauropod lineage.Geochemical analyses suggest its affinity with coeval magmatism in southeastern China,while new rhyolite zircon U-Pb dating yields an age of 151.6±2.2 Ma,further indicating a transition from arc magmatism to back-arc extension driven by Paleo-Pacific subduction during the Late Jurassic.These studies also confirm that,as early as 156 Ma,the Tunxi Basin was already a key habitat for mamenchisaurids.The Late Jurassic subduction of the Paleo-Pacific Plate caused extensive magmatism across eastern China.This intense tectonic shift likely induced abrupt environmental changes in relative basins.Severe volcanic activity drastically reduced the habitat of mamenchisaurids,prompting a northwestward and southward radiation trend-presents a coherent scene of volcanic eruptions,environmental catastrophe,and dinosaurs migrating.展开更多
Subduction initiation is a critical part of the plate tectonic system,but its geodynamic process is still poorly understood due to the lack of well-preserved geological records.Based on new zircon U–Pb–Hf isotopic a...Subduction initiation is a critical part of the plate tectonic system,but its geodynamic process is still poorly understood due to the lack of well-preserved geological records.Based on new zircon U–Pb–Hf isotopic and whole-rock geochemical data,we report the first discovery of a latest Cambrian–Early Ordovician forearc-arc rock sequence in the Eastern Alps.This sequence includes granitic gneisses,amphibolites,and amphibole plagiogneisses from the ophiolitic Speik Complex and Gleinalpe Complex.These rocks exhibit geochemical affinities with typical oceanic plagiogranites,forearc basalts(FABs),and island arc basalts,respectively.The latest Cambrian plagiogranitic protoliths(491±2 Ma)are shearing-type plagiogranites that were formed in the tectonic setting of forearc spreading.The latest Cambrian FABs(496–489 Ma)have similar geochemical compositions and positiveεHf(t)values(+2.5 to+14.9)to the depleted mid-ocean ridge basalts.However,they show depletion in high field strength elements(HFSEs;e.g.,Nb,Ta,and Zr)and have relatively low Ti/V ratios.These features suggest that they were derived from a depleted mantle source modified by subducting slab-released components in a forearc environment.The Early Ordovician basaltic protoliths(476–472 Ma)of amphibole plagiogneisses show enrichment in large ion lithophile elements and depletion in HFSEs(e.g.Nb,Ta,Zr,and Hf),implying a mature island arc environment.These metaigneous rocks,along with the coeval boninite-like high-Mg amphibolites near the study area,form a typical rock sequence resembling that of the Izu–Bonin–Mariana(IBM)arc system.The Speik and Gleinalpe complexes document a complete magmatic evolution from subduction initiation to mature arc development within the West Proto-Tethys Ocean.Integrating our new data with published work,we reconstruct the late Ediacaran–early Paleozoic tectonic evolution of the northern Gondwana.During the late Ediacaran–early Cambrian,the rollback of the West Proto-Tethys oceanic plate triggered the separation of the Wechsel-Silvretta-Gleinalpe continental arc from the northern Gondwana.This process led to the formation of the Speik back-arc oceanic basin,a southwestern branch of the West Proto-Tethys Ocean.In the latest Cambrian–Early Ordovician,subduction initiation occurred in the Speik Ocean,which subsequently developed into an intra-oceanic arc system.During the Early Devonian,the Speik Ocean closed and the Wechsel-Silvretta-Gleinalpe continental arc reattached to the Gondwana,as evidenced by the metamorphic event at ca.400 Ma.展开更多
Based on a normalized difference vegetation index(NDVI)dataset for 1982-2021,this work investigates the principal modes of interannual variability in summer NDVI over eastern Siberia using the year-to-year increment m...Based on a normalized difference vegetation index(NDVI)dataset for 1982-2021,this work investigates the principal modes of interannual variability in summer NDVI over eastern Siberia using the year-to-year increment method and empirical orthogonal function(EOF)analysis.The first three principal modes(EOF1-3)of the year-to-year increment of summer NDVI(NDVI_DY)exhibit a regionally consistent mode,a western-eastern dipole mode,and a northern-southern dipole mode,respectively.Further analysis shows that sea surface temperature(SST)in the tropical Indian Ocean in February-March and western Siberian soil moisture in April could influence EOF1.EOF2 is modulated by April Northwest Pacific SST and western Siberian soil moisture in May.May North Atlantic SST and sea ice in the Kara Sea in the preceding October significantly affect EOF3.Using the year-to-year increment method and multiple linear regression analysis,prediction schemes for EOF1-3 are developed based on these predictors.To assess the predictive skill of these schemes,one-year-out cross-validation and independent hindcast methods are employed.The temporal correlation coefficients between observed EOF1-3 and the cross-validation results are 0.62,0.46,and 0.37,respectively,exceeding the 95%confidence level.In addition,reconstructed schemes for summer NDVI are developed using predicted NDVI_DY and the observed principal modes of NDVI_DY.Independent hindcasts of NDVI anomalies during 2019-2021 also present consistent distributions with the observed results.展开更多
There is a gradual increase in the proportion of renewable energy sources.Green hydrogen has the potential to become one of the major energy carriers in the future.The Russian Federation,in partnership with countries ...There is a gradual increase in the proportion of renewable energy sources.Green hydrogen has the potential to become one of the major energy carriers in the future.The Russian Federation,in partnership with countries in the Asia-Pacific region and especially China,has the potential to play a significant role in green hydrogen market.This study assessed the potential of developing green hydrogen energy based on wind power in the Far Eastern Federal District(FEFD)of the Russian Federation.Empirical wind speed data were collected from 20 meteorological stations in 4 regions(Sakhalinskaya Oblast’,Primorskiy Krai,Khabarovskiy Krai,and Amurskaya Oblast’)of the FEFD.The Weibull distribution was used to predict the potential of green hydrogen production.Five different methods(Empirical Method of Justus(EMJ),Empirical Method of Lysen(EML),Maximum Likelihood Method(MLE),Power Density Method(PDM),and Median and Quartiles Method(MQM))were used to determine the parameters(scape factor and scale factor)of the Weibull distribution.We calculated the total electricity generation potential based on the technical specifications of the three wind turbines:Senvion 6150 onshore,H165-4.0 MW,and Vestas V150-4.2 MW.The results showed that Vladivostok,Pogibi,Ilyinskiy,Yuzhno-Kuril’sk,Severo-Kuril’sk,Kholmsk,and Okha stations had the higher potential of green hydrogen production,of which Vladivostok exhibited the highest potential of green hydrogen production using the wind turbine of H165-4.0 MW,up to 2.56×10^(5) kg/a.In terms of economic analysis,the levelized cost of hydrogen(LCOH)values of lower than 4.00 USD/kg were obtained at Yuzhno-Kuril’sk,Ilyinskiy,Pogibi,and Vladivostok stations using the wind turbine of H165-4.0 MW,with the values of 3.54,3.50,3.24,and 2.55 USD/kg,respectively.This study concluded that the FEFD possesses significant potential in the production of green hydrogen and,with appropriate investment,has the potential to become a significant hub for green hydrogen trading in the Asia-Pacific region.展开更多
Inside the China Pavilion at Expo 2025 Osaka,Kansai,Japan,a cultural feast steeped in Liaoning’s history and brimming with its innovative spirit is unfolding.Under the banner“Poetic landscapes,Boundless vitality”,L...Inside the China Pavilion at Expo 2025 Osaka,Kansai,Japan,a cultural feast steeped in Liaoning’s history and brimming with its innovative spirit is unfolding.Under the banner“Poetic landscapes,Boundless vitality”,Liaoning Week employs intangible heritage showcases,live performances and exhibitions to reveal the province’s distinctive cultural charm.展开更多
Rock-ice avalanches have frequently occurred in the Eastern Himalayan Syntaxis region due to climate change and active tectonic movements.These events commonly trigger catastrophic geohazard chains,including debris fl...Rock-ice avalanches have frequently occurred in the Eastern Himalayan Syntaxis region due to climate change and active tectonic movements.These events commonly trigger catastrophic geohazard chains,including debris flows,river blockages,and floods.This study focuses on the Zelongnong Basin,analyzing the geomorphic and dynamic characteristics of high-altitude disasters.The basin exhibits typical vertical zonation,with disaster sources initiating at elevations exceeding 4000 m and runout distances reaching up to 10 km.The disaster chain movement involves complex dynamic effects,including impact disintegration,soil-rock mixture arching,dynamic erosion,and debris deposition,enhancing understanding of the flow behavior and dynamic characteristics of rock-ice avalanches.The presence of ice significantly increases mobility due to lubrication and frictional melting.In the disaster event of September 10,2020,the maximum flow velocity and thickness reached 40 m/s and 43 m,respectively.Furthermore,continuous deformation of the Zelongnong glacier moraine was observed,with maximum cumulative deformations of 44.68 m in the distance direction and 25.96 m in the azimuth direction from March 25,2022,to August 25,2022.In the future,the risk of rock-ice avalanches in the Eastern Himalayan Syntaxis region will remain extremely high,necessitating a focus on early warning and risk mitigation strategies for such basin disasters.展开更多
The Eastern Block of the North China Craton(NCC)(Fig.1)has undergone severe lithospheric destruction,with crustal thinning down to 100 km depth(Chen et al.,2009),contrasting sharply with the stable Kalahari and Rae cr...The Eastern Block of the North China Craton(NCC)(Fig.1)has undergone severe lithospheric destruction,with crustal thinning down to 100 km depth(Chen et al.,2009),contrasting sharply with the stable Kalahari and Rae cratons.However,there remains controversy over the destruction pattern(e.g.,Zhu et al.,2017).During the Early Mesozoic,crustal thickening occurred in the Xuhuai and Qinling orogens,followed by lithospheric delamination leading to crustal thinning(Chen et al.,2023).The middle and upper crustal thinning in the Yanshan and Taihang uplifts was induced by mafic magma underplating(Ji et al.,2009).展开更多
The Sangong Cu-Ni sulfide mineralized mafic-ultramafic intrusion is located on the southern margin of the Bogeda-Harlik belt,eastern Tianshan,China.The intrusion is a well-differentiated complex and is comprised of le...The Sangong Cu-Ni sulfide mineralized mafic-ultramafic intrusion is located on the southern margin of the Bogeda-Harlik belt,eastern Tianshan,China.The intrusion is a well-differentiated complex and is comprised of leucogabbro,gabbro,olivine gabbro,Pl-bearing peridotite,and Pl-bearing pyroxenite.The Pl-bearing pyroxenite hosts both irregularly disseminated sulfide and round droplet sulfide.The intrusive rocks have a wide range of SiO_(2)(42.1 wt.%-50.48 wt.%)and MgO(6.21 wt.%-22.11 wt.%),and are enriched in light rare earth elements(LREE),large-ion lithophile elements(LILE;e.g.,Rb,Ba,Sr,and Pb),and palladium platinum group elements(PPGE)but depleted in high-field-strength elements(HFSE;e.g.,Nb,Ta,and Ti)and iridium PGEs(IPGE).These geochemical characteristics indicate that the Sangong mafic-ultramafic intrusion was derived from high degree of partial melting of depleted mantle and interacted with subduction-related material.The low Pd/Ir(3.21-27.44)but high Ni/Cu(1.64-24.16)ratios,combined with the olivine crystals with low Fo(60.88-78.65)and Ni(54.99 ppm-1688.87 ppm)concentrations suggest that the parental magma of the Sangong intrusion were likely high MgO basaltic in composition that experienced extensive evolution prior emplacement.The Ce/Pb ratios(5.8-13.6)and Nb/U ratios(11.6-30.3)of the intrusive rocks all range between MORB and crustal values,the Nb/Yb and Th/Yb values are close to the lower crust values,together with the low Se/S ratios[(17-100)×10^(-6))]suggest that the magma experienced assimilation not only in mantle source but also in conduit,but the degree of crustal contamination is limited.The Cu/Pd ratios of the rocks range from 3.9×10^(4) to 10.8×10^(4),and the Cu/Zr ratios of Pl-bearing pyroxenite in the Sangong intrusion are>1,combined with the presence of sulfide droplets in the Pl-bearing pyroxenite,indicating the parental magma experienced sulfide saturation and the economical ore bodies may present in the depth of the intrusion.Furthermore,given the discovery of the Baixintan and Yueyawan deposits,we propose the DananhuHarlik belt as an essential prospecting target for Cu-Ni mineralization in North Xinjiang.展开更多
Sheep have been one of the most important groups of animals since ancient times.However,the knowledge of their migration routes and genetic relationships is still poorly understood.To investigate sheep maternal migrat...Sheep have been one of the most important groups of animals since ancient times.However,the knowledge of their migration routes and genetic relationships is still poorly understood.To investigate sheep maternal migration histories alongside Eurasian communications routes,in this study,we obtain mitochondrial genomes(mitogenomes)from 17 sheep remains in 6 Chinese sites and 1 Uzbekistan site dated 4429–3100 years before present(BP).By obtaining the mitogenomes from the sheep(4429–3556 BP)found in the Tongtian Cave site in Xinjiang,Altai region of northwest China,our results support the emergence of haplogroup C sheep in Xinjiang as early as 4429–3556 BP.The combined phylogenetic analyses with extant ancient and modern sheep mitogenomes suggest that the Uzbekistan-Altai region may have been a migration hub for early sheep in eastern Asia.At least two migration events have taken place for sheep crossing Eurasia to China,one passing by Uzbekistan and Northwest China to the middle and lower reaches of the Yellow River at approximately 4000 BP and another following the Altai region to middle Inner Mongolia from 4429 BP to 2500 BP.Overall,this study provides further evidence for early sheep utilization and migration patterns in Eastern Asia.展开更多
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.
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.
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 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.
基金supported by the China Geological Survey(DD20230221)the National Natural Science Foundation of China(42102018)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB26000000).
文摘A prevailing theory suggests that volcanic eruptions triggered environmental changes,which compelled dinosaurs to migrate in search of new habitats.Compelling evidence for this hypothesis has now been discovered in the Tunxi Basin of eastern China.During the Late Mesozoic,the subduction of the Pacific Plate beneath southeastern China led to multi-stage volcanic activity.The Tunxi Formation in the basin,the first reported Upper Jurassic volcanic unit in the eastern Jiangnan orogen.It overlies the stratum bearing the easternmost mamenchisaurids,which is the dominant Asian sauropod lineage.Geochemical analyses suggest its affinity with coeval magmatism in southeastern China,while new rhyolite zircon U-Pb dating yields an age of 151.6±2.2 Ma,further indicating a transition from arc magmatism to back-arc extension driven by Paleo-Pacific subduction during the Late Jurassic.These studies also confirm that,as early as 156 Ma,the Tunxi Basin was already a key habitat for mamenchisaurids.The Late Jurassic subduction of the Paleo-Pacific Plate caused extensive magmatism across eastern China.This intense tectonic shift likely induced abrupt environmental changes in relative basins.Severe volcanic activity drastically reduced the habitat of mamenchisaurids,prompting a northwestward and southward radiation trend-presents a coherent scene of volcanic eruptions,environmental catastrophe,and dinosaurs migrating.
基金supported by the National Natural Science Foundation of China(Grant Nos.42272244 and 91755212)Taishan Scholars(Grant No.ts20190918).
文摘Subduction initiation is a critical part of the plate tectonic system,but its geodynamic process is still poorly understood due to the lack of well-preserved geological records.Based on new zircon U–Pb–Hf isotopic and whole-rock geochemical data,we report the first discovery of a latest Cambrian–Early Ordovician forearc-arc rock sequence in the Eastern Alps.This sequence includes granitic gneisses,amphibolites,and amphibole plagiogneisses from the ophiolitic Speik Complex and Gleinalpe Complex.These rocks exhibit geochemical affinities with typical oceanic plagiogranites,forearc basalts(FABs),and island arc basalts,respectively.The latest Cambrian plagiogranitic protoliths(491±2 Ma)are shearing-type plagiogranites that were formed in the tectonic setting of forearc spreading.The latest Cambrian FABs(496–489 Ma)have similar geochemical compositions and positiveεHf(t)values(+2.5 to+14.9)to the depleted mid-ocean ridge basalts.However,they show depletion in high field strength elements(HFSEs;e.g.,Nb,Ta,and Zr)and have relatively low Ti/V ratios.These features suggest that they were derived from a depleted mantle source modified by subducting slab-released components in a forearc environment.The Early Ordovician basaltic protoliths(476–472 Ma)of amphibole plagiogneisses show enrichment in large ion lithophile elements and depletion in HFSEs(e.g.Nb,Ta,Zr,and Hf),implying a mature island arc environment.These metaigneous rocks,along with the coeval boninite-like high-Mg amphibolites near the study area,form a typical rock sequence resembling that of the Izu–Bonin–Mariana(IBM)arc system.The Speik and Gleinalpe complexes document a complete magmatic evolution from subduction initiation to mature arc development within the West Proto-Tethys Ocean.Integrating our new data with published work,we reconstruct the late Ediacaran–early Paleozoic tectonic evolution of the northern Gondwana.During the late Ediacaran–early Cambrian,the rollback of the West Proto-Tethys oceanic plate triggered the separation of the Wechsel-Silvretta-Gleinalpe continental arc from the northern Gondwana.This process led to the formation of the Speik back-arc oceanic basin,a southwestern branch of the West Proto-Tethys Ocean.In the latest Cambrian–Early Ordovician,subduction initiation occurred in the Speik Ocean,which subsequently developed into an intra-oceanic arc system.During the Early Devonian,the Speik Ocean closed and the Wechsel-Silvretta-Gleinalpe continental arc reattached to the Gondwana,as evidenced by the metamorphic event at ca.400 Ma.
基金supported by the National Key Research and Development Program of China[grant number 2022YFE0106800]the National Natural Science Foundation of China[grant number 42230603]+1 种基金the Innovation Group Project of Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)[grant number 311024001]supported by Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)[grant number SML2023SP209].
文摘Based on a normalized difference vegetation index(NDVI)dataset for 1982-2021,this work investigates the principal modes of interannual variability in summer NDVI over eastern Siberia using the year-to-year increment method and empirical orthogonal function(EOF)analysis.The first three principal modes(EOF1-3)of the year-to-year increment of summer NDVI(NDVI_DY)exhibit a regionally consistent mode,a western-eastern dipole mode,and a northern-southern dipole mode,respectively.Further analysis shows that sea surface temperature(SST)in the tropical Indian Ocean in February-March and western Siberian soil moisture in April could influence EOF1.EOF2 is modulated by April Northwest Pacific SST and western Siberian soil moisture in May.May North Atlantic SST and sea ice in the Kara Sea in the preceding October significantly affect EOF3.Using the year-to-year increment method and multiple linear regression analysis,prediction schemes for EOF1-3 are developed based on these predictors.To assess the predictive skill of these schemes,one-year-out cross-validation and independent hindcast methods are employed.The temporal correlation coefficients between observed EOF1-3 and the cross-validation results are 0.62,0.46,and 0.37,respectively,exceeding the 95%confidence level.In addition,reconstructed schemes for summer NDVI are developed using predicted NDVI_DY and the observed principal modes of NDVI_DY.Independent hindcasts of NDVI anomalies during 2019-2021 also present consistent distributions with the observed results.
文摘There is a gradual increase in the proportion of renewable energy sources.Green hydrogen has the potential to become one of the major energy carriers in the future.The Russian Federation,in partnership with countries in the Asia-Pacific region and especially China,has the potential to play a significant role in green hydrogen market.This study assessed the potential of developing green hydrogen energy based on wind power in the Far Eastern Federal District(FEFD)of the Russian Federation.Empirical wind speed data were collected from 20 meteorological stations in 4 regions(Sakhalinskaya Oblast’,Primorskiy Krai,Khabarovskiy Krai,and Amurskaya Oblast’)of the FEFD.The Weibull distribution was used to predict the potential of green hydrogen production.Five different methods(Empirical Method of Justus(EMJ),Empirical Method of Lysen(EML),Maximum Likelihood Method(MLE),Power Density Method(PDM),and Median and Quartiles Method(MQM))were used to determine the parameters(scape factor and scale factor)of the Weibull distribution.We calculated the total electricity generation potential based on the technical specifications of the three wind turbines:Senvion 6150 onshore,H165-4.0 MW,and Vestas V150-4.2 MW.The results showed that Vladivostok,Pogibi,Ilyinskiy,Yuzhno-Kuril’sk,Severo-Kuril’sk,Kholmsk,and Okha stations had the higher potential of green hydrogen production,of which Vladivostok exhibited the highest potential of green hydrogen production using the wind turbine of H165-4.0 MW,up to 2.56×10^(5) kg/a.In terms of economic analysis,the levelized cost of hydrogen(LCOH)values of lower than 4.00 USD/kg were obtained at Yuzhno-Kuril’sk,Ilyinskiy,Pogibi,and Vladivostok stations using the wind turbine of H165-4.0 MW,with the values of 3.54,3.50,3.24,and 2.55 USD/kg,respectively.This study concluded that the FEFD possesses significant potential in the production of green hydrogen and,with appropriate investment,has the potential to become a significant hub for green hydrogen trading in the Asia-Pacific region.
文摘Inside the China Pavilion at Expo 2025 Osaka,Kansai,Japan,a cultural feast steeped in Liaoning’s history and brimming with its innovative spirit is unfolding.Under the banner“Poetic landscapes,Boundless vitality”,Liaoning Week employs intangible heritage showcases,live performances and exhibitions to reveal the province’s distinctive cultural charm.
基金granted by the National Natural Science Foundation of China(Grant Nos.U2244227 and U2244226)the National Key R&D Program of China(Grant No.2022YFC3004301)China Geological Survey Project(Grant No.DD20230538)。
文摘Rock-ice avalanches have frequently occurred in the Eastern Himalayan Syntaxis region due to climate change and active tectonic movements.These events commonly trigger catastrophic geohazard chains,including debris flows,river blockages,and floods.This study focuses on the Zelongnong Basin,analyzing the geomorphic and dynamic characteristics of high-altitude disasters.The basin exhibits typical vertical zonation,with disaster sources initiating at elevations exceeding 4000 m and runout distances reaching up to 10 km.The disaster chain movement involves complex dynamic effects,including impact disintegration,soil-rock mixture arching,dynamic erosion,and debris deposition,enhancing understanding of the flow behavior and dynamic characteristics of rock-ice avalanches.The presence of ice significantly increases mobility due to lubrication and frictional melting.In the disaster event of September 10,2020,the maximum flow velocity and thickness reached 40 m/s and 43 m,respectively.Furthermore,continuous deformation of the Zelongnong glacier moraine was observed,with maximum cumulative deformations of 44.68 m in the distance direction and 25.96 m in the azimuth direction from March 25,2022,to August 25,2022.In the future,the risk of rock-ice avalanches in the Eastern Himalayan Syntaxis region will remain extremely high,necessitating a focus on early warning and risk mitigation strategies for such basin disasters.
基金granted by the National Key R&D Plan(Grant No.2022YFF0800702)project SINOPROBE on sub-project SINOPROBE-01,National Natural Science Foundation of China(Grants 41274003,41674101,and 41974112)。
文摘The Eastern Block of the North China Craton(NCC)(Fig.1)has undergone severe lithospheric destruction,with crustal thinning down to 100 km depth(Chen et al.,2009),contrasting sharply with the stable Kalahari and Rae cratons.However,there remains controversy over the destruction pattern(e.g.,Zhu et al.,2017).During the Early Mesozoic,crustal thickening occurred in the Xuhuai and Qinling orogens,followed by lithospheric delamination leading to crustal thinning(Chen et al.,2023).The middle and upper crustal thinning in the Yanshan and Taihang uplifts was induced by mafic magma underplating(Ji et al.,2009).
基金supported by the National Key R&D Program of China(No.2017YFC0601204).
文摘The Sangong Cu-Ni sulfide mineralized mafic-ultramafic intrusion is located on the southern margin of the Bogeda-Harlik belt,eastern Tianshan,China.The intrusion is a well-differentiated complex and is comprised of leucogabbro,gabbro,olivine gabbro,Pl-bearing peridotite,and Pl-bearing pyroxenite.The Pl-bearing pyroxenite hosts both irregularly disseminated sulfide and round droplet sulfide.The intrusive rocks have a wide range of SiO_(2)(42.1 wt.%-50.48 wt.%)and MgO(6.21 wt.%-22.11 wt.%),and are enriched in light rare earth elements(LREE),large-ion lithophile elements(LILE;e.g.,Rb,Ba,Sr,and Pb),and palladium platinum group elements(PPGE)but depleted in high-field-strength elements(HFSE;e.g.,Nb,Ta,and Ti)and iridium PGEs(IPGE).These geochemical characteristics indicate that the Sangong mafic-ultramafic intrusion was derived from high degree of partial melting of depleted mantle and interacted with subduction-related material.The low Pd/Ir(3.21-27.44)but high Ni/Cu(1.64-24.16)ratios,combined with the olivine crystals with low Fo(60.88-78.65)and Ni(54.99 ppm-1688.87 ppm)concentrations suggest that the parental magma of the Sangong intrusion were likely high MgO basaltic in composition that experienced extensive evolution prior emplacement.The Ce/Pb ratios(5.8-13.6)and Nb/U ratios(11.6-30.3)of the intrusive rocks all range between MORB and crustal values,the Nb/Yb and Th/Yb values are close to the lower crust values,together with the low Se/S ratios[(17-100)×10^(-6))]suggest that the magma experienced assimilation not only in mantle source but also in conduit,but the degree of crustal contamination is limited.The Cu/Pd ratios of the rocks range from 3.9×10^(4) to 10.8×10^(4),and the Cu/Zr ratios of Pl-bearing pyroxenite in the Sangong intrusion are>1,combined with the presence of sulfide droplets in the Pl-bearing pyroxenite,indicating the parental magma experienced sulfide saturation and the economical ore bodies may present in the depth of the intrusion.Furthermore,given the discovery of the Baixintan and Yueyawan deposits,we propose the DananhuHarlik belt as an essential prospecting target for Cu-Ni mineralization in North Xinjiang.
基金funded by the National Key Research and Development Program of China(2021YFF1000701)the Young S&T Talent Training Program of Guangdong Provincial Association for S&T,China(SKXRC202205)+1 种基金the Foundation for the Creative Team and Key Laboratory in Higher Education of Guangdong(2019KCXTD006 and 2019KSYS011)the National Natural Science Foundations of China(31961133031)。
文摘Sheep have been one of the most important groups of animals since ancient times.However,the knowledge of their migration routes and genetic relationships is still poorly understood.To investigate sheep maternal migration histories alongside Eurasian communications routes,in this study,we obtain mitochondrial genomes(mitogenomes)from 17 sheep remains in 6 Chinese sites and 1 Uzbekistan site dated 4429–3100 years before present(BP).By obtaining the mitogenomes from the sheep(4429–3556 BP)found in the Tongtian Cave site in Xinjiang,Altai region of northwest China,our results support the emergence of haplogroup C sheep in Xinjiang as early as 4429–3556 BP.The combined phylogenetic analyses with extant ancient and modern sheep mitogenomes suggest that the Uzbekistan-Altai region may have been a migration hub for early sheep in eastern Asia.At least two migration events have taken place for sheep crossing Eurasia to China,one passing by Uzbekistan and Northwest China to the middle and lower reaches of the Yellow River at approximately 4000 BP and another following the Altai region to middle Inner Mongolia from 4429 BP to 2500 BP.Overall,this study provides further evidence for early sheep utilization and migration patterns in Eastern Asia.
