Active tectonics in an area includes ongoing or recent geologic events.This paper investigates the tectonic influence on the subsidence,uplift and tilt of western Saurashtra through morphotectonic analysis of ten wate...Active tectonics in an area includes ongoing or recent geologic events.This paper investigates the tectonic influence on the subsidence,uplift and tilt of western Saurashtra through morphotectonic analysis of ten watersheds along with characteristics of relief and drainage orientation.Watersheds 7-9 to the north(N)are tectonically active,which can be linked with the North Kathiawar Fault System(NKFS)and followed by watersheds 6,10,1,4 and 5.Stream-length gradient index and sinuosity index indicate the effect of tectonic events along the master streams in watersheds 6-9.Higher R^(2)values of the linear curve fit for watershed 7 indicate its master stream is much more tectonically active than the others.The R^(2)curve fitting model and earthquake magnitude/depth analysis confirm the region to be active.The reactivation of the NKFS most likely led to the vertical movement of western Saurashtra.展开更多
Seasonal snow cover is a key global climate and hydrological system component drawing considerable attention due to glob-al warming conditions.However,the spatiotemporal snow cover patterns are challenging in western ...Seasonal snow cover is a key global climate and hydrological system component drawing considerable attention due to glob-al warming conditions.However,the spatiotemporal snow cover patterns are challenging in western Jilin,China due to natural condi-tions and sparse observation.Hence,this study investigated the spatiotemporal patterns of snow cover using fine-resolution passive mi-crowave(PMW)snow depth(SD)data from 1987 to 2018,and revealed the potential influence of climate factors on SD variations.The results indicated that the interannual range of SD was between 2.90 cm and 9.60 cm during the snowy winter seasons and the annual mean SD showed a slightly increasing trend(P>0.05)at a rate of 0.009 cm/yr.In snowmelt periods,the snow cover contributed to an increase in volumetric soil water,and the change in SD was significantly affected by air temperature.The correlation between SD and air temperature was negative,while the correlation between SD and precipitation was positive during December and March.In March,the correlation coefficient exceeded 0.5 in Zhenlai,Da’an,Qianan,and Qianguo counties.However,the SD and precipitation were neg-atively correlated over western Jilin in October,and several subregions presented a negative correlation between SD and precipitation in November and April.展开更多
There are a large number of Mesozoic intrusive and volcanic rocks in western Liaoning of China,which is an ideal place to study the Mesozoic Paleo-Pacific subduction processes,and lithospheric destruc-tion of North Ch...There are a large number of Mesozoic intrusive and volcanic rocks in western Liaoning of China,which is an ideal place to study the Mesozoic Paleo-Pacific subduction processes,and lithospheric destruc-tion of North China Craton.Detailed petrographic,zircon U-Pb dating and geochemical studies of the Early Jurassic granites in Huashan pluton,Xingcheng,western Liaoning,indicate that the Early Jurassic granites were formed at 184-174 Ma,mainly composed of syenite and monzogranite.The geochemical characteristics show high contents of SiO_(2),Al_(2)O_(3)and Na_(2)O+K_(2)O,low contents of Fe_(2)O_(3)and MgO,enrichment in LREEs and LILEs,and depletion in HREEs and HFSEs,and have a high content of Sr and low contents of Y and Yb,with weak negative Eu anomalies and slightly negative anomalies of Ce,indicating that they are a set of intermediate-acidic adakitic granites in high-K calc-alkaline series.All the facts significantly suggest that the Early Jurassic adakitic granites were formed at the active continental margin in the context of Paleo-Pacific plate subduction.展开更多
Tourette syndrome is a common neuropsychiatric disorder that affects the physical and mental health of children.Early detection,diagnosis,and treatment are crucial to prevent serious impacts on the affected children,t...Tourette syndrome is a common neuropsychiatric disorder that affects the physical and mental health of children.Early detection,diagnosis,and treatment are crucial to prevent serious impacts on the affected children,their families,and society.In recent years,there has been an increasing trend towards using a combination of methods in the clinical treatment of children with Tourette syndrome.This approach has achieved remarkable results,leading to a reduction in the rate of Tourette syndrome symptoms in children.In recent years,a combination of clinical methods has been used to treat children with Tourette syndrome,resulting in significant improvement in control rates.This article reviews the etiology of infantile Tourette syndrome and the progress made in Chinese and Western medicine treatments,providing a reference for further treatment of the condition.展开更多
This study reveals the strengthened interdecadal relationship between the western North Pacific summer monsoon(WNPSM)and tropical central-western Pacific sea surface temperature anomaly(SSTA)in summer after the early ...This study reveals the strengthened interdecadal relationship between the western North Pacific summer monsoon(WNPSM)and tropical central-western Pacific sea surface temperature anomaly(SSTA)in summer after the early 1990s.In the first period(1979–91,P1),the WNPSM-related precipitation anomaly and horizontal wind anomaly present themselves as an analogous Pacific-Japan(PJ)-like pattern,generally considered to be related to the Niño-3 index in the preceding winter.During the subsequent period(1994–2019,P2),the WNPSM-related precipitation anomaly presents a zonal dipole pattern,correlated significantly with the concurrent SSTA in the Niño-4 and tropical western Pacific regions.The negative(positive)SSTA in the tropical western Pacific and positive(negative)SSTA in the Niño-4 region,could work together to influence the WNPSM,noting that the two types of anomalous SSTA configurations enhance(weaken)the WNPSM by the positive(negative)phase PJ-like wave and Gill response,respectively,with an anomalous cyclone(anticyclone)located in the WNPSM,which shows obvious symmetry about the anomalous circulation.Specifically,the SSTA in Niño-4 impacts the WNPSM by an atmospheric Gill response,with a stronger(weaker)WNPSM along with a positive(negative)SSTA in the Niño-4 region.Furthermore,the SSTA in the tropical western Pacific exerts an influence on the WNPSM by a PJ-like wave,with a stronger(weaker)WNPSM along with a negative(positive)SSTA in the tropical western Pacific.In general,SSTAs in the tropical western Pacific and Niño-4 areas could work together to exert influence on the WNPSM,with the effect most likely to occur in the El Niño(La Niña)developing year in P2.However,the SSTAs in the tropical western Pacific worked alone to exert an influence on the WNPSM mainly in 2013,2014,2016,and 2017,and the SSTAs in the Niño-4 region worked alone to exert an influence on the WNPSM mainly in Central Pacific(CP)La Niña developing years.The sensitivity experiments also can reproduce the PJ-like wave/Gill response associated with SSTA in the tropical western Pacific/Niño-4 regions.Therefore,the respective and synergistic impacts from the Niño-4 region and the tropical western Pacific on the WNPSM have been revealed,which helps us to acquire a better understanding of the interdecadal variations of the WNPSM and its associated climate influences.展开更多
Western Altun in Xinjiang is an important area,where lithium(Li)-bearing pegmatites have been found in recent years.However,the complex terrain and harsh environment of western Altun exacerbates in prospecting for Li-...Western Altun in Xinjiang is an important area,where lithium(Li)-bearing pegmatites have been found in recent years.However,the complex terrain and harsh environment of western Altun exacerbates in prospecting for Li-bearing pegmatites.Therefore,remote-sensing techniques can be an effective means for prospecting Li-bearing pegmatites.In this study,the fault information and lithologyical information in the region were obtained using the median-resolution remotesensing image Landsat-8,the radar image Sentinel-1 and hyperspectral data GF-5.Using Landsat-8 data,the hydroxyl alteration information closely related to pegmatite in the region was extracted by principal component analysis,pseudoanomaly processing and other methods.The high spatial resolution remote-sensing data WorldView-2 and WorldView-3 short-wave infrared images were used and analyzed by principal component analysis(PCA),the band ratio method and multi-class machine learning(ML),combined with conventional thresholds specified the algorithms used to automatically extract Li-bearing pegmatite information.Finally,the Li-bearing pegmatite exploration area was determined,based on a comprehensive analysis of the faults,hydroxyl alteration lithology and Li-bearing pegmatite information.Field investigations have verified that the distribution of pegmatites in the central part of the study area is consistent with that of Li-bearing pegmatites extracted in this study.This study provides a new technique for prospecting Li-bearing pegmatites,which shows that remote-sensing technology possesses great potential for identifying lithium-bearing pegmatites,especially in areas that are not readily accessible.展开更多
The unprecedented Zhengzhou heavy rainfall in July 2021 occurred under the background of a northward shift of the western Pacific subtropical high(WPSH).Although the occurrence of this extreme event could not be captu...The unprecedented Zhengzhou heavy rainfall in July 2021 occurred under the background of a northward shift of the western Pacific subtropical high(WPSH).Although the occurrence of this extreme event could not be captured by seasonal predictions,a skillful prediction of the WPSH variation might have warned us of the increased probability of extreme weather events in Central and Northern China.However,the mechanism for the WPSH variation in July 2021 and its seasonal predictability are still unknown.Here,the observed northward shift of the WPSH in July 2021 is shown to correspond to a meridional dipole pattern of the 850-hPa geopotential height to the east of China,the amplitude of which became the strongest since 1979.The meridional dipole pattern is two nodes of the Pacific–Japan pattern.To investigate the predictability of the WPSH variation,a 21-member ensemble of seasonal predictions initiated from the end of June 2021 was conducted.The predictable and unpredictable components of the meridional dipole pattern were identified from the ensemble simulations.Its predictable component is driven by positive precipitation anomalies over the tropical western Pacific.The positive precipitation anomalies are caused by positive horizonal advection of the mean moist enthalpy by southwesterly anomalies to the northwestern flank of anticyclonic anomalies excited by the existing La Niña,which is skillfully predicted by the model.The leading mode of the unpredictable component is associated with the atmospheric internal intraseasonal oscillations,which are not initialized in the simulations.The relative contributions of the predictable and unpredictable components to the observed northward shift of the WPSH at 850 hPa are 28.0%and 72.0%,respectively.展开更多
Gastric cancer(GC)is a malignant tumor originating from the gastric epithelium,and its incidence and mortality rates rank third among all malignant tumors worldwide.It is also one of the most common cancers in China a...Gastric cancer(GC)is a malignant tumor originating from the gastric epithelium,and its incidence and mortality rates rank third among all malignant tumors worldwide.It is also one of the most common cancers in China and is treated predominantly by Western medicine in clinical practice.However,with the advancements in medical technology and informatics,the values of traditional Chinese medicine(TCM)in preventing and treating GC and improving prognosis have increasingly been recognized.According to TCM,clinical manifestations of GC can be divided into Yege(dysphagia),regurgitation,stomach pain,and Zhengxia(abdominal mass).Due to the unbalanced distribution of health care resources in China,most GC patients already have progressive or advanced-stage disease at the first diagnosis.As a result,most GC patients have poor physical function,and surgery or chemotherapy alone will aggravate the impairment to the immune function and seriously affect the quality of life.In contrast,TCM therapies have shown promising efficacy in the management of these patients.Here we review the role of the integrated TCM and Western medicine in treating advanced GC.展开更多
The Dunde iron-zinc polymetallic deposit is one of large iron deposits occurred in the Awulale Metallogenetic Belt,Western Tianshan(NW-China).This study reports new geochronology and geochemistry for granite in the Du...The Dunde iron-zinc polymetallic deposit is one of large iron deposits occurred in the Awulale Metallogenetic Belt,Western Tianshan(NW-China).This study reports new geochronology and geochemistry for granite in the Dunde mining area in order to constrain the tectonicmagmatic activities and metallogenesis of this region.Granites in the southwest of Dunde mining area are mainly syenogranites intruded into volcanics of the Dahalajunshan Formation in the Early Carboniferous,and they are far from the area where ore bodies and mineralized altered rocks are widely developed.LA-ICP-MS U–Pb zircon dating indicates that Dunde syenogranite was at 306.8±1.0 Ma,which could constrain the upper limit of metallogenic age for this deposit.The Dunde granites are high SiO_(2)(73.41–80.07 wt%),high differentiation index(D.I.=89.7–95.0),weakly peraluminous to metaluminous(A/CNK=0.94–1.08),and they are enriched in LILE and LREE and depleted in Eu,Ba,Sr and P_(2)O_(5),indicating that they belong to highly fractionated Ⅰ-type granite.Based on εHf values(+9.2 to+10.5)for zircon and high εNd(-t)values(+4.7 to+5.8)for whole-rock,and the two-stage model ages for 601–735 Ma,suggest that the magma source could be the juvenile lower crust.Combined with regional geological setting,the 306.8 Ma Dunde granites are formed in post-collision extensional tectonic setting.展开更多
Western Desert represents a major oil and gas province in Egypt producing more than 50%of the country’s oil production.Oil and gas blend occurs in most producing fields,however,the genetic link between gas and liquid...Western Desert represents a major oil and gas province in Egypt producing more than 50%of the country’s oil production.Oil and gas blend occurs in most producing fields,however,the genetic link between gas and liquid hydrocarbon phases are not well-constrained.Obayied sub-basin in the Western Desert where oil and gas phases coexist in the Middle Jurassic sandstones of the Khatatba Formation provides an ideal place to investigate the link between oil and gas generation.Geochemical analyses on rock samples(Rock–Eval pyrolysis,vitrinite reflectance,R_(o))and gases(molecular and isotopic composition)were conducted in order to identify the genetic characteristics of the hydrocarbon phases produced.Maturity-relevant parameters(Rock–Eval T_(max),vitrinite reflectance R_(o))elucidate that only Middle Jurassic Khatatba organofacies capable of generating wet and dry hydrocarbon gases.Additionally,the enrichment of C_(7)normal alkanes,mono-branched alkanes relative to polybranched components in the Obayied gases reflect their generation via cracking of oil.Basin modelling results confirm gas generation through both primary and secondary cracking.However,secondary cracking of liquid hydrocarbon phases is volumetrically more significant.Primary cracking of the Khatatba organofacies likely predate and catalyze the secondary cracking of the liquid phases and therefore the volume of generated gas increases incrementally eastward where both processes coexist.The present study highlights the significant role of secondary cracking in the generation and accumulation of huge gas accumulations in the basins containing oil-prone source intervals.展开更多
Western Subarctic Gyre(WSG),which possesses distinctive differences in oceanographic and biogeochemical processes,is situated in the northwest subarctic Pacific.The WSG is characterized by high nutrient and low chloro...Western Subarctic Gyre(WSG),which possesses distinctive differences in oceanographic and biogeochemical processes,is situated in the northwest subarctic Pacific.The WSG is characterized by high nutrient and low chlorophyll.We carried out a field investigation in this area in summer 2020 and performed microscopic observation,cytometric counting,and RuBisCO large subunit(rbc L)gene analysis to understand the community structure and spatial distribution of chromophytic phytoplankton better.Microscopic method revealed that total phytoplankton(>10μm,including Bacillariophyta,Dinoflagellata,Ochrophyta,and Chlorophyta)abundances ranged(0.6×10^(3))-(167.4×10^(3))cells/L with an increasing trend from south to north.Dinoflagellates and Pennatae diatoms dominated the phytoplankton assemblages in the southern and northern stations,respectively.Major chromophytic phytoplankton groups derived from rbc L genes included Haptophyta,Ochrophyta,Bacillariophyta,as well as rarely occurring groups,such as Xanthophyta,Cyanobacteria,Dinoflagellata,Rhodophyta,and Cryptophyta.At the phylum level,Haptophyta was the most abundant phylum,accounting for approximately 30.80%of the total obtained operational taxonomic units in all samples.Ochrophyta and Bacillariophyta were the second and third most abundant phylum,and their relative abundance was 20.26% and 19.60%,respectively.Further,redundancy analysis showed that high proportion of diatoms(e.g.,microscopic and rbc L methods)was positively correlated with nutrients(e.g.,dissolved inorganic nitrogen(DIN),dissolved inorganic phosphorous,and dissolved silicate(DSi))and negatively correlated with temperature and salinity.The proportion of Ochrophyta,Rhodophyta,and Cyanobateria identified by rbc L genes was positively correlated with salinity and temperature and showed negative correlation to nutrients.This work is the first molecular study of phytoplankton accomplished in the WSG,and our results show some discrepancies between morphological observation and rbc L gene sequences,which highlight the necessity of combining the microscopic and molecular methods to reveal the diversity of phytoplankton in marine environment.展开更多
The Yili Block in the Western Tianshan orogen is a key area for understanding the early crustal formation and evolution of the Central Asian orogenic belt,due to the widely-distributed Precambrian rocks.Also,it hosts ...The Yili Block in the Western Tianshan orogen is a key area for understanding the early crustal formation and evolution of the Central Asian orogenic belt,due to the widely-distributed Precambrian rocks.Also,it hosts a lot of medium–to large-scale sedimentary exhalative(SEDEX)Pb-Zn deposits that mainly occur in Proterozoic metamorphosed clasticcarbonate rocks.In this study,LA-ICP-MS U-Pb analyses were carried out on detrital zircons in siltstones of the Precambrian Haerdaban Group in the Haerdaban Pb-Zn deposit and magmatic zircons in the diorite dyke that cuts through the strata and orebodies.The maximum depositional age of the siltstones was determined to be about 604 Ma,the diorite having formed at approximately 500 Ma.As such,the Haerdaban Group was most likely formed in the Neoproterozoic Sinian,rather than the previously considered Mesoproterozoic Changchengian.Detrital materials of the Haerdaban Group were mostly derived from the Nanhua–Sinian mafic dykes and granitic rocks around Lake Sayram at the northern margin of the Yili Block.It is proposed that the Yili Block,together with the Kazakhstan and Central Tianshan blocks and the Tarim Craton,might all pertain to the same Rodinia supercontinent,which has great potential for targeting large to super-large SEDEX Pb-Zn deposits.展开更多
Submarine canyon is an important channel for long-distance sediment transport, and an important part of deepwater sedimentary system. The large-scale Rizhao Canyons have been discovered for the first time in 2015 in t...Submarine canyon is an important channel for long-distance sediment transport, and an important part of deepwater sedimentary system. The large-scale Rizhao Canyons have been discovered for the first time in 2015 in the continental slope area of the western South China Sea. Based on the interpretation and analysis of multi-beam bathymetry and two-dimensional multi-channel seismic data, the geology of the canyons has however not been studied yet. In this paper, the morphology and distribution characteristics of the canyon are carefully described,the sedimentary filling structure and its evolution process of the canyon are analyzed, and then its controlling factors are discussed. The results show that Rizhao Canyons group is a large slope restricted canyon group composed of one east-west west main and nine branch canyons extending to the south. The canyon was formed from the late Miocene to the Quaternary. The east-west main canyon is located in the transition zone between the northern terrace and the southern Zhongjiannan Slope, and it is mainly formed by the scouring and erosion of the material source from the west, approximately along the slope direction. Its development and evolution is mainly controlled by sediment supply and topographic conditions, the development of 9 branch canyons is mainly controlled by gravity flow and collapse from the east-west main canyon. This understanding result is a supplement to the study of “source-channel–sink” sedimentary system in the west of the South China Sea, and has important guiding significance for the study of marine geological hazards.展开更多
Glacier shrinkage is a globally occurring phenomena.High-resolution change detection based on frequent mapping and monitoring of high-altitude glaciers is necessary to precisely evaluate future water availability and ...Glacier shrinkage is a globally occurring phenomena.High-resolution change detection based on frequent mapping and monitoring of high-altitude glaciers is necessary to precisely evaluate future water availability and to understand glacier evolution under different climatic scenarios in the Hindukush-Karakoram-Himalayan(HKH)region.This also holds true for the Bhaga basin of the western Himalaya.This study investigates glacier and glacier lake changes in the Bhaga basin,over the last five decades based on satellite imagery including Corona KH4(1971),Landsat 7 Enhanced Thematic Mapper Plus(ETM+;2000),Linear Imaging Self-Scanning Sensor(LISS Ⅳ;2013),and Sentinel 2(2020).Regional temperature and precipitation trends were evaluated from gridded climatic datasets(1900–2020).In the Bhaga basin 306 glaciers(>0.2 km^(2))were mapped with a total area of 360.3±4.0 km^(2),of which 55.7±0.6 km^(2)was covered with debris in 2013.The total glacier covered area decreased by∼8.2±1.5%(0.16±0.03%yr-1)during the entire observation period 1971–2020,with noticeable heterogeneity between tributary watersheds.In the past two decades(2000–2020),the deglaciation rate has increased significantly(0.25%yr-1)compared to the previous decades(1971–2000;0.12%yr-1).Glacier lake area increased by 0.6±0.1 km^(2)(0.012 km^(2)yr-1)between 1971 and 2020.The NCEP/NCAR climatic data reveals an increase of 0.63℃in temperature and a decrease of 6.39 mm in precipitation for the period 1948–2018.In comparison,APHRODITE data shows an increasing trend in temperature of 1.14℃between 1961 and 2015 and decreasing trend in precipitation of 31 mm between 1951 and 2007.Both NCEP/NCAR and APHRODITE data reveal significant temperature increase and precipitation decrease since the 1990s,which have probably augmented ice loss in the Bhaga basin during the early 21st century.展开更多
As an important site for tourism activities,mountainous areas may generate greater tourism risks than plain areas due to potential natural disasters,social issues,scenic area management,and tourist behavior.Western Si...As an important site for tourism activities,mountainous areas may generate greater tourism risks than plain areas due to potential natural disasters,social issues,scenic area management,and tourist behavior.Western Sichuan Plateau is mostly mountainous area and tourism is its pillar industry,Therefore,the assessment of the tourism risks on the Western Sichuan Plateau is of academic value and practical significance.In this study,we use statistical and remote sensing data,fishbone diagram,and the entropy weighting method to construct a tourism risk evaluation model and classify risks into different levels,and we also use a geographic information system(GIS)for spatial mapping to quantify and spatialize the results.The objectives are 1)to identify the risk sources in the Western Sichuan Plateau and analyze their causal mechanisms,precisely reveal the distribution of tourism risks in the study area;2)improve the precision of tourism risk evaluation in scenic areas and analyze the causes and spatial distribution patterns of tourism risks and propose targeted management measures.This study found that the evaluation results of the four elements of hazard,exposure,vulnerability,and disaster prevention and mitigation capacity on the Western Sichuan Plateau showed significant spatial variability,depending on the natural conditions and the quantity difference of tourism resources in different regions.In addition,the tourism risk is low in most areas of the Western Sichuan Plateau,and disaster prevention and mitigation capacity is higher in areas with high tourism risk where attractions are densely populated and tourism is concentrated.Our study can provide a reference for future analyses of tourism risks in mountainous tourist areas such as in China and worldwide.展开更多
Oceanic front plays a significant role in the ocean vertical mixing and the regulation of air-sea interaction,among others.The western branch of the subarctic front(WSAF)located in the Northwest Pacific has attained l...Oceanic front plays a significant role in the ocean vertical mixing and the regulation of air-sea interaction,among others.The western branch of the subarctic front(WSAF)located in the Northwest Pacific has attained lots of attention given its strong intensity and widespread influence on this region.In this study,we take advantage of the merged sea surface temperature(SST)at a high spatial resolution of 0.05°to investigate the characteristics of WSAF.The front detection algorithm that combines the Sobel operator and histogram analysis is adopted.It is advantageous in both preserving the front intensity represented by the SST gradient as well as reducing the detection noise level.We systematically applied this algorithm to the daily SST products for front detection,based on which the WSAF characteristics including its intensity,occurrence of frequency,latitudinal position and coverage area are then extracted.WSAF is mostly located within a small latitude range between 40°N and 41°N with a clear seasonal trend in its intensity that peaks in the winter and troughs in the summer.The seasonal variation of WSAF intensity is almost consistent throughout the temporal period of interest from 2010 to 2018.Similar seasonality is observed for its occurrence of frequency with the winter-summer contrast reaching up to5%.The findings presented here shall help better interpret the WSAF characteristics in the long-term run as well as their impact on the regional weather and climate patterns at high spatial resolution.展开更多
The Tibetan Plateau is an important area for studying global climate change,but the answers to many scientific problems remain unknown.Here,we present new information from the lacustrine sedimentary record in the west...The Tibetan Plateau is an important area for studying global climate change,but the answers to many scientific problems remain unknown.Here,we present new information from the lacustrine sedimentary record in the western Tibetan Plateau,related to the third most-recent glaciations.Continuous sediment data,including sporopollen,particle size,total organic carbon,mass susceptibility,CaCO_(3),CaSO_(4),BaSO_(4)contents and chronological data,were reconstructed and revealed that climate and environmental conditions obviously and distinctly changed between 600 and 700 thousand years ago.In comparison,the data obtained from the Guliya ice core in this area also corresponds to the global glacial climatic characteristics recorded in basin sediments in the eastern and southeastern regions of the plateau and to the information obtained from ice cores in the Antarctic and Arctic regions.In this study,we conclude that the main reason for the glaciations and new tectonic movement must be a geomagnetic polarity reversal 774 thousand years ago(from Matuyama to Brunhes).Indeed,the results of this study suggest that the described reversal event might have influenced the current global climate pattern and will continue to impact climatic changes in the future.展开更多
Cross-border investment is essential for western China’s globalization.Global value chain(GVC)forms cross-border investment networks between industries in western China and overseas cities.Focusing on GVC,this study ...Cross-border investment is essential for western China’s globalization.Global value chain(GVC)forms cross-border investment networks between industries in western China and overseas cities.Focusing on GVC,this study uses the social network analysis method,entropy method,multi-index comprehensive evaluation method,and quadratic assignment procedure analysis method to examine the characteristics and influencing factors of the urban networks of research and development(R&D),production,and sales formed as a result of the overseas investments of listed manufacturing companies in western China.Results showed that the three types of investment networks involved multiple industry types and multiple central cities with differentiated diversity and multicentrality.The R&D urban network’s leading sub-industries were the mechanical equipment and instruments,medicine and biological products,and metal and nonmetal industries.The destination cities were mostly those home to educational and scientific research centers.The production urban network’s leading sub-industries were the mechanical equipment,instrument,and food and beverage industries.The destination cities were mostly regional central cities in developing countries.The sales urban network’s leading sub-industries were the mechanical equipment and instrument,metal and nonmetal,and petrochemical and plastics industries.The destination cities were numerous and scattered.In addition,the R&D urban network easily formed specialized clusters,core nodes easily controlled the production urban network,and individual nodes did not easily control the sales urban network.Technological and economic system advantages greatly impacted the three network types.Considering the different influencing factors,this study suggests optimizing the institutional investment environment to narrow the institutional gap,adjusting and optimizing the investment layout to expand overseas markets,and increasing R&D funds to stimulate technological progress and overseas investments in western China.展开更多
The western North Pacific summer monsoon(WNPSM)is an important subcomponent of the Asian summer monsoon.The equatorial zonal wind(EZW)in the lower troposphere over the western Pacific may play a critical role in the e...The western North Pacific summer monsoon(WNPSM)is an important subcomponent of the Asian summer monsoon.The equatorial zonal wind(EZW)in the lower troposphere over the western Pacific may play a critical role in the evolution of the El Niño-Southern Oscillation(ENSO).The possible linkage between the EZW over the western Pacific and the offequatorial monsoonal winds associated with the WNPSM and its decadal changes have not yet been fully understood.Here,we find a non-stationary relationship between the WNPSM and the western Pacific EZW,significantly strengthening their correlation around the late 1980s/early 1990s.This observed shift in the WNPSM–EZW relationship could be explained by the changes in the related sea surface temperature(SST)configurations across the tropical oceans.The enhanced influence from the springtime tropical North Atlantic,summertime tropical central Pacific,and maritime continent SST anomalies may be working together in contributing to the recent intensified WNPSM–EZW co-variability.The observed recent strengthening of the WNPSM–EZW relationship may profoundly impact the climate system,including prompting more effective feedback from the WNPSM on subsequent ENSO evolution and bolstering a stronger biennial tendency of the WNPSM–ENSO coupled system.The results obtained herein imply that the WNPSM,EZW,ENSO,and the tropical North Atlantic SST may be closely linked within a unified climate system with a quasi-biennial rhythm occurring during recent decades,accompanied by a reinforcement of the WNPSM–ENSO interplay quite possibly triggered by enhanced tropical Pacific–Atlantic cross-basin interactions.These results highlight the importance of the tropical Atlantic cross-basin influences in shaping the spatial structure of WNPSM-related wind anomalies and the WNPSM–ENSO interaction.展开更多
基金Research Development Fund(IIT Bombay)supported SM。
文摘Active tectonics in an area includes ongoing or recent geologic events.This paper investigates the tectonic influence on the subsidence,uplift and tilt of western Saurashtra through morphotectonic analysis of ten watersheds along with characteristics of relief and drainage orientation.Watersheds 7-9 to the north(N)are tectonically active,which can be linked with the North Kathiawar Fault System(NKFS)and followed by watersheds 6,10,1,4 and 5.Stream-length gradient index and sinuosity index indicate the effect of tectonic events along the master streams in watersheds 6-9.Higher R^(2)values of the linear curve fit for watershed 7 indicate its master stream is much more tectonically active than the others.The R^(2)curve fitting model and earthquake magnitude/depth analysis confirm the region to be active.The reactivation of the NKFS most likely led to the vertical movement of western Saurashtra.
基金Under the auspices of the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA28110502)Science and Technology Development Plan Project of Jilin Province(No.20220202035NC)+1 种基金National Natural Science Foundation of China(No.41871248)Changchun Science and Technology Development Plan Project(No.21ZY12)。
文摘Seasonal snow cover is a key global climate and hydrological system component drawing considerable attention due to glob-al warming conditions.However,the spatiotemporal snow cover patterns are challenging in western Jilin,China due to natural condi-tions and sparse observation.Hence,this study investigated the spatiotemporal patterns of snow cover using fine-resolution passive mi-crowave(PMW)snow depth(SD)data from 1987 to 2018,and revealed the potential influence of climate factors on SD variations.The results indicated that the interannual range of SD was between 2.90 cm and 9.60 cm during the snowy winter seasons and the annual mean SD showed a slightly increasing trend(P>0.05)at a rate of 0.009 cm/yr.In snowmelt periods,the snow cover contributed to an increase in volumetric soil water,and the change in SD was significantly affected by air temperature.The correlation between SD and air temperature was negative,while the correlation between SD and precipitation was positive during December and March.In March,the correlation coefficient exceeded 0.5 in Zhenlai,Da’an,Qianan,and Qianguo counties.However,the SD and precipitation were neg-atively correlated over western Jilin in October,and several subregions presented a negative correlation between SD and precipitation in November and April.
基金Supported by the National Key R&D Program of China(No.2016YFC0666108-02).
文摘There are a large number of Mesozoic intrusive and volcanic rocks in western Liaoning of China,which is an ideal place to study the Mesozoic Paleo-Pacific subduction processes,and lithospheric destruc-tion of North China Craton.Detailed petrographic,zircon U-Pb dating and geochemical studies of the Early Jurassic granites in Huashan pluton,Xingcheng,western Liaoning,indicate that the Early Jurassic granites were formed at 184-174 Ma,mainly composed of syenite and monzogranite.The geochemical characteristics show high contents of SiO_(2),Al_(2)O_(3)and Na_(2)O+K_(2)O,low contents of Fe_(2)O_(3)and MgO,enrichment in LREEs and LILEs,and depletion in HREEs and HFSEs,and have a high content of Sr and low contents of Y and Yb,with weak negative Eu anomalies and slightly negative anomalies of Ce,indicating that they are a set of intermediate-acidic adakitic granites in high-K calc-alkaline series.All the facts significantly suggest that the Early Jurassic adakitic granites were formed at the active continental margin in the context of Paleo-Pacific plate subduction.
基金Shaanxi Province International Science and Technology Cooperation Accounting Items-Key Items(2023-GHZD-41)Shaanxi University of Traditional Chinese Medicine Research Students New Ability Proposal Item(CXSJ202332)。
文摘Tourette syndrome is a common neuropsychiatric disorder that affects the physical and mental health of children.Early detection,diagnosis,and treatment are crucial to prevent serious impacts on the affected children,their families,and society.In recent years,there has been an increasing trend towards using a combination of methods in the clinical treatment of children with Tourette syndrome.This approach has achieved remarkable results,leading to a reduction in the rate of Tourette syndrome symptoms in children.In recent years,a combination of clinical methods has been used to treat children with Tourette syndrome,resulting in significant improvement in control rates.This article reviews the etiology of infantile Tourette syndrome and the progress made in Chinese and Western medicine treatments,providing a reference for further treatment of the condition.
基金supported by the National Natural Science Foundation of China[grant number 42275025]the Youth Innovation Promotion Association of the Chinese Academy of Sciences[grant number 2023084].
基金supported by the Fund Project of the Hengyang Normal University(2022QD11)the National Natural Science Foundation of China(Grant No.42105063).
文摘This study reveals the strengthened interdecadal relationship between the western North Pacific summer monsoon(WNPSM)and tropical central-western Pacific sea surface temperature anomaly(SSTA)in summer after the early 1990s.In the first period(1979–91,P1),the WNPSM-related precipitation anomaly and horizontal wind anomaly present themselves as an analogous Pacific-Japan(PJ)-like pattern,generally considered to be related to the Niño-3 index in the preceding winter.During the subsequent period(1994–2019,P2),the WNPSM-related precipitation anomaly presents a zonal dipole pattern,correlated significantly with the concurrent SSTA in the Niño-4 and tropical western Pacific regions.The negative(positive)SSTA in the tropical western Pacific and positive(negative)SSTA in the Niño-4 region,could work together to influence the WNPSM,noting that the two types of anomalous SSTA configurations enhance(weaken)the WNPSM by the positive(negative)phase PJ-like wave and Gill response,respectively,with an anomalous cyclone(anticyclone)located in the WNPSM,which shows obvious symmetry about the anomalous circulation.Specifically,the SSTA in Niño-4 impacts the WNPSM by an atmospheric Gill response,with a stronger(weaker)WNPSM along with a positive(negative)SSTA in the Niño-4 region.Furthermore,the SSTA in the tropical western Pacific exerts an influence on the WNPSM by a PJ-like wave,with a stronger(weaker)WNPSM along with a negative(positive)SSTA in the tropical western Pacific.In general,SSTAs in the tropical western Pacific and Niño-4 areas could work together to exert influence on the WNPSM,with the effect most likely to occur in the El Niño(La Niña)developing year in P2.However,the SSTAs in the tropical western Pacific worked alone to exert an influence on the WNPSM mainly in 2013,2014,2016,and 2017,and the SSTAs in the Niño-4 region worked alone to exert an influence on the WNPSM mainly in Central Pacific(CP)La Niña developing years.The sensitivity experiments also can reproduce the PJ-like wave/Gill response associated with SSTA in the tropical western Pacific/Niño-4 regions.Therefore,the respective and synergistic impacts from the Niño-4 region and the tropical western Pacific on the WNPSM have been revealed,which helps us to acquire a better understanding of the interdecadal variations of the WNPSM and its associated climate influences.
基金supported by the National Key Research and Development Program of the China Geological Survey(DD20190173)the Fundamental Research Funds for the Institute of Mineral Resources,the Chinese Academy of Geological Sciences(KK2102)+1 种基金the National Natural Science Foundation of China(42172332)the Chinese Geological Survey Project(DD20190379)。
文摘Western Altun in Xinjiang is an important area,where lithium(Li)-bearing pegmatites have been found in recent years.However,the complex terrain and harsh environment of western Altun exacerbates in prospecting for Li-bearing pegmatites.Therefore,remote-sensing techniques can be an effective means for prospecting Li-bearing pegmatites.In this study,the fault information and lithologyical information in the region were obtained using the median-resolution remotesensing image Landsat-8,the radar image Sentinel-1 and hyperspectral data GF-5.Using Landsat-8 data,the hydroxyl alteration information closely related to pegmatite in the region was extracted by principal component analysis,pseudoanomaly processing and other methods.The high spatial resolution remote-sensing data WorldView-2 and WorldView-3 short-wave infrared images were used and analyzed by principal component analysis(PCA),the band ratio method and multi-class machine learning(ML),combined with conventional thresholds specified the algorithms used to automatically extract Li-bearing pegmatite information.Finally,the Li-bearing pegmatite exploration area was determined,based on a comprehensive analysis of the faults,hydroxyl alteration lithology and Li-bearing pegmatite information.Field investigations have verified that the distribution of pegmatites in the central part of the study area is consistent with that of Li-bearing pegmatites extracted in this study.This study provides a new technique for prospecting Li-bearing pegmatites,which shows that remote-sensing technology possesses great potential for identifying lithium-bearing pegmatites,especially in areas that are not readily accessible.
基金supported by the National Natural Science Foundation of China under Grant No.41988101the Chinese Academy of Sciences under Grant XDA20060102the China Postdoctoral Science Foundation under Grant No.2022T150638 and K.C.Wong Education Foundation.
文摘The unprecedented Zhengzhou heavy rainfall in July 2021 occurred under the background of a northward shift of the western Pacific subtropical high(WPSH).Although the occurrence of this extreme event could not be captured by seasonal predictions,a skillful prediction of the WPSH variation might have warned us of the increased probability of extreme weather events in Central and Northern China.However,the mechanism for the WPSH variation in July 2021 and its seasonal predictability are still unknown.Here,the observed northward shift of the WPSH in July 2021 is shown to correspond to a meridional dipole pattern of the 850-hPa geopotential height to the east of China,the amplitude of which became the strongest since 1979.The meridional dipole pattern is two nodes of the Pacific–Japan pattern.To investigate the predictability of the WPSH variation,a 21-member ensemble of seasonal predictions initiated from the end of June 2021 was conducted.The predictable and unpredictable components of the meridional dipole pattern were identified from the ensemble simulations.Its predictable component is driven by positive precipitation anomalies over the tropical western Pacific.The positive precipitation anomalies are caused by positive horizonal advection of the mean moist enthalpy by southwesterly anomalies to the northwestern flank of anticyclonic anomalies excited by the existing La Niña,which is skillfully predicted by the model.The leading mode of the unpredictable component is associated with the atmospheric internal intraseasonal oscillations,which are not initialized in the simulations.The relative contributions of the predictable and unpredictable components to the observed northward shift of the WPSH at 850 hPa are 28.0%and 72.0%,respectively.
文摘Gastric cancer(GC)is a malignant tumor originating from the gastric epithelium,and its incidence and mortality rates rank third among all malignant tumors worldwide.It is also one of the most common cancers in China and is treated predominantly by Western medicine in clinical practice.However,with the advancements in medical technology and informatics,the values of traditional Chinese medicine(TCM)in preventing and treating GC and improving prognosis have increasingly been recognized.According to TCM,clinical manifestations of GC can be divided into Yege(dysphagia),regurgitation,stomach pain,and Zhengxia(abdominal mass).Due to the unbalanced distribution of health care resources in China,most GC patients already have progressive or advanced-stage disease at the first diagnosis.As a result,most GC patients have poor physical function,and surgery or chemotherapy alone will aggravate the impairment to the immune function and seriously affect the quality of life.In contrast,TCM therapies have shown promising efficacy in the management of these patients.Here we review the role of the integrated TCM and Western medicine in treating advanced GC.
基金supported by Special Fund for Basic Scientific Research of Central Colleges,Chang’an University(Grant No.:300102279210)the Natural Science Foundation of Shaanxi Province(Grant No.:2019JQ-690)the geological and mineral survey evaluation project of China Geological Survey(Grant No.:DD20190065).
文摘The Dunde iron-zinc polymetallic deposit is one of large iron deposits occurred in the Awulale Metallogenetic Belt,Western Tianshan(NW-China).This study reports new geochronology and geochemistry for granite in the Dunde mining area in order to constrain the tectonicmagmatic activities and metallogenesis of this region.Granites in the southwest of Dunde mining area are mainly syenogranites intruded into volcanics of the Dahalajunshan Formation in the Early Carboniferous,and they are far from the area where ore bodies and mineralized altered rocks are widely developed.LA-ICP-MS U–Pb zircon dating indicates that Dunde syenogranite was at 306.8±1.0 Ma,which could constrain the upper limit of metallogenic age for this deposit.The Dunde granites are high SiO_(2)(73.41–80.07 wt%),high differentiation index(D.I.=89.7–95.0),weakly peraluminous to metaluminous(A/CNK=0.94–1.08),and they are enriched in LILE and LREE and depleted in Eu,Ba,Sr and P_(2)O_(5),indicating that they belong to highly fractionated Ⅰ-type granite.Based on εHf values(+9.2 to+10.5)for zircon and high εNd(-t)values(+4.7 to+5.8)for whole-rock,and the two-stage model ages for 601–735 Ma,suggest that the magma source could be the juvenile lower crust.Combined with regional geological setting,the 306.8 Ma Dunde granites are formed in post-collision extensional tectonic setting.
文摘Western Desert represents a major oil and gas province in Egypt producing more than 50%of the country’s oil production.Oil and gas blend occurs in most producing fields,however,the genetic link between gas and liquid hydrocarbon phases are not well-constrained.Obayied sub-basin in the Western Desert where oil and gas phases coexist in the Middle Jurassic sandstones of the Khatatba Formation provides an ideal place to investigate the link between oil and gas generation.Geochemical analyses on rock samples(Rock–Eval pyrolysis,vitrinite reflectance,R_(o))and gases(molecular and isotopic composition)were conducted in order to identify the genetic characteristics of the hydrocarbon phases produced.Maturity-relevant parameters(Rock–Eval T_(max),vitrinite reflectance R_(o))elucidate that only Middle Jurassic Khatatba organofacies capable of generating wet and dry hydrocarbon gases.Additionally,the enrichment of C_(7)normal alkanes,mono-branched alkanes relative to polybranched components in the Obayied gases reflect their generation via cracking of oil.Basin modelling results confirm gas generation through both primary and secondary cracking.However,secondary cracking of liquid hydrocarbon phases is volumetrically more significant.Primary cracking of the Khatatba organofacies likely predate and catalyze the secondary cracking of the liquid phases and therefore the volume of generated gas increases incrementally eastward where both processes coexist.The present study highlights the significant role of secondary cracking in the generation and accumulation of huge gas accumulations in the basins containing oil-prone source intervals.
基金Supported by the National Key Research and Development Program of China(No.2019YFD0901401)the National Natural Science Foundation of China(Nos.42176206,81900630)+2 种基金the Natural Science Foundation of Shandong Province(No.ZR2021MD071)the“One Hundred Talents”Project of Guangxi(No.6020303891251)the Outstanding Youth Project of Yunnan Provincial Department of Science and Technology(No.2019F1019)。
文摘Western Subarctic Gyre(WSG),which possesses distinctive differences in oceanographic and biogeochemical processes,is situated in the northwest subarctic Pacific.The WSG is characterized by high nutrient and low chlorophyll.We carried out a field investigation in this area in summer 2020 and performed microscopic observation,cytometric counting,and RuBisCO large subunit(rbc L)gene analysis to understand the community structure and spatial distribution of chromophytic phytoplankton better.Microscopic method revealed that total phytoplankton(>10μm,including Bacillariophyta,Dinoflagellata,Ochrophyta,and Chlorophyta)abundances ranged(0.6×10^(3))-(167.4×10^(3))cells/L with an increasing trend from south to north.Dinoflagellates and Pennatae diatoms dominated the phytoplankton assemblages in the southern and northern stations,respectively.Major chromophytic phytoplankton groups derived from rbc L genes included Haptophyta,Ochrophyta,Bacillariophyta,as well as rarely occurring groups,such as Xanthophyta,Cyanobacteria,Dinoflagellata,Rhodophyta,and Cryptophyta.At the phylum level,Haptophyta was the most abundant phylum,accounting for approximately 30.80%of the total obtained operational taxonomic units in all samples.Ochrophyta and Bacillariophyta were the second and third most abundant phylum,and their relative abundance was 20.26% and 19.60%,respectively.Further,redundancy analysis showed that high proportion of diatoms(e.g.,microscopic and rbc L methods)was positively correlated with nutrients(e.g.,dissolved inorganic nitrogen(DIN),dissolved inorganic phosphorous,and dissolved silicate(DSi))and negatively correlated with temperature and salinity.The proportion of Ochrophyta,Rhodophyta,and Cyanobateria identified by rbc L genes was positively correlated with salinity and temperature and showed negative correlation to nutrients.This work is the first molecular study of phytoplankton accomplished in the WSG,and our results show some discrepancies between morphological observation and rbc L gene sequences,which highlight the necessity of combining the microscopic and molecular methods to reveal the diversity of phytoplankton in marine environment.
基金funded by the Key Project of the National Natural Science Foundation of China(Grant No.42130804)the National Key R&D Program of China(Grant No.2018YFC0604003)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.35942019012)the State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences(Grant No.MSFGPMR201810)。
文摘The Yili Block in the Western Tianshan orogen is a key area for understanding the early crustal formation and evolution of the Central Asian orogenic belt,due to the widely-distributed Precambrian rocks.Also,it hosts a lot of medium–to large-scale sedimentary exhalative(SEDEX)Pb-Zn deposits that mainly occur in Proterozoic metamorphosed clasticcarbonate rocks.In this study,LA-ICP-MS U-Pb analyses were carried out on detrital zircons in siltstones of the Precambrian Haerdaban Group in the Haerdaban Pb-Zn deposit and magmatic zircons in the diorite dyke that cuts through the strata and orebodies.The maximum depositional age of the siltstones was determined to be about 604 Ma,the diorite having formed at approximately 500 Ma.As such,the Haerdaban Group was most likely formed in the Neoproterozoic Sinian,rather than the previously considered Mesoproterozoic Changchengian.Detrital materials of the Haerdaban Group were mostly derived from the Nanhua–Sinian mafic dykes and granitic rocks around Lake Sayram at the northern margin of the Yili Block.It is proposed that the Yili Block,together with the Kazakhstan and Central Tianshan blocks and the Tarim Craton,might all pertain to the same Rodinia supercontinent,which has great potential for targeting large to super-large SEDEX Pb-Zn deposits.
基金The Major Special Project of Guangdong Provincial Laboratory of Southern Marine Science and Engineering(Guangzhou) under contract No. GML2019ZD0207the National Natural Science Foundation of China under contract No. U20A20100the China Geological Survey Project under contract Nos DD20221712, DD20221719 and DD20191002。
文摘Submarine canyon is an important channel for long-distance sediment transport, and an important part of deepwater sedimentary system. The large-scale Rizhao Canyons have been discovered for the first time in 2015 in the continental slope area of the western South China Sea. Based on the interpretation and analysis of multi-beam bathymetry and two-dimensional multi-channel seismic data, the geology of the canyons has however not been studied yet. In this paper, the morphology and distribution characteristics of the canyon are carefully described,the sedimentary filling structure and its evolution process of the canyon are analyzed, and then its controlling factors are discussed. The results show that Rizhao Canyons group is a large slope restricted canyon group composed of one east-west west main and nine branch canyons extending to the south. The canyon was formed from the late Miocene to the Quaternary. The east-west main canyon is located in the transition zone between the northern terrace and the southern Zhongjiannan Slope, and it is mainly formed by the scouring and erosion of the material source from the west, approximately along the slope direction. Its development and evolution is mainly controlled by sediment supply and topographic conditions, the development of 9 branch canyons is mainly controlled by gravity flow and collapse from the east-west main canyon. This understanding result is a supplement to the study of “source-channel–sink” sedimentary system in the west of the South China Sea, and has important guiding significance for the study of marine geological hazards.
基金the University Grant Commission, New Delhi (3090/ (NET–DEC.2014) for financial support during field visitsthe Department of Science and Technology, Govt of India, for sponsoring the project “Himalayan Cryosphere: Science and Society”
文摘Glacier shrinkage is a globally occurring phenomena.High-resolution change detection based on frequent mapping and monitoring of high-altitude glaciers is necessary to precisely evaluate future water availability and to understand glacier evolution under different climatic scenarios in the Hindukush-Karakoram-Himalayan(HKH)region.This also holds true for the Bhaga basin of the western Himalaya.This study investigates glacier and glacier lake changes in the Bhaga basin,over the last five decades based on satellite imagery including Corona KH4(1971),Landsat 7 Enhanced Thematic Mapper Plus(ETM+;2000),Linear Imaging Self-Scanning Sensor(LISS Ⅳ;2013),and Sentinel 2(2020).Regional temperature and precipitation trends were evaluated from gridded climatic datasets(1900–2020).In the Bhaga basin 306 glaciers(>0.2 km^(2))were mapped with a total area of 360.3±4.0 km^(2),of which 55.7±0.6 km^(2)was covered with debris in 2013.The total glacier covered area decreased by∼8.2±1.5%(0.16±0.03%yr-1)during the entire observation period 1971–2020,with noticeable heterogeneity between tributary watersheds.In the past two decades(2000–2020),the deglaciation rate has increased significantly(0.25%yr-1)compared to the previous decades(1971–2000;0.12%yr-1).Glacier lake area increased by 0.6±0.1 km^(2)(0.012 km^(2)yr-1)between 1971 and 2020.The NCEP/NCAR climatic data reveals an increase of 0.63℃in temperature and a decrease of 6.39 mm in precipitation for the period 1948–2018.In comparison,APHRODITE data shows an increasing trend in temperature of 1.14℃between 1961 and 2015 and decreasing trend in precipitation of 31 mm between 1951 and 2007.Both NCEP/NCAR and APHRODITE data reveal significant temperature increase and precipitation decrease since the 1990s,which have probably augmented ice loss in the Bhaga basin during the early 21st century.
基金Social Science Foundation of Liaoning Province(L21BJY028)。
文摘As an important site for tourism activities,mountainous areas may generate greater tourism risks than plain areas due to potential natural disasters,social issues,scenic area management,and tourist behavior.Western Sichuan Plateau is mostly mountainous area and tourism is its pillar industry,Therefore,the assessment of the tourism risks on the Western Sichuan Plateau is of academic value and practical significance.In this study,we use statistical and remote sensing data,fishbone diagram,and the entropy weighting method to construct a tourism risk evaluation model and classify risks into different levels,and we also use a geographic information system(GIS)for spatial mapping to quantify and spatialize the results.The objectives are 1)to identify the risk sources in the Western Sichuan Plateau and analyze their causal mechanisms,precisely reveal the distribution of tourism risks in the study area;2)improve the precision of tourism risk evaluation in scenic areas and analyze the causes and spatial distribution patterns of tourism risks and propose targeted management measures.This study found that the evaluation results of the four elements of hazard,exposure,vulnerability,and disaster prevention and mitigation capacity on the Western Sichuan Plateau showed significant spatial variability,depending on the natural conditions and the quantity difference of tourism resources in different regions.In addition,the tourism risk is low in most areas of the Western Sichuan Plateau,and disaster prevention and mitigation capacity is higher in areas with high tourism risk where attractions are densely populated and tourism is concentrated.Our study can provide a reference for future analyses of tourism risks in mountainous tourist areas such as in China and worldwide.
基金The Natural Science Foundation of Jiangsu Province under contract No.BK20210666the National Natural Science Foundation of China under contract Nos 41620104003 and 42006163+2 种基金the Startup Foundation for Introducing Talent of Nanjing University of Information Science&Technologythe National Key Research and Development Program of China under contract No.2021YFB3901004the Graduate Innovation Project of Jiangsu Province under contract No.KYCX21_0980。
文摘Oceanic front plays a significant role in the ocean vertical mixing and the regulation of air-sea interaction,among others.The western branch of the subarctic front(WSAF)located in the Northwest Pacific has attained lots of attention given its strong intensity and widespread influence on this region.In this study,we take advantage of the merged sea surface temperature(SST)at a high spatial resolution of 0.05°to investigate the characteristics of WSAF.The front detection algorithm that combines the Sobel operator and histogram analysis is adopted.It is advantageous in both preserving the front intensity represented by the SST gradient as well as reducing the detection noise level.We systematically applied this algorithm to the daily SST products for front detection,based on which the WSAF characteristics including its intensity,occurrence of frequency,latitudinal position and coverage area are then extracted.WSAF is mostly located within a small latitude range between 40°N and 41°N with a clear seasonal trend in its intensity that peaks in the winter and troughs in the summer.The seasonal variation of WSAF intensity is almost consistent throughout the temporal period of interest from 2010 to 2018.Similar seasonality is observed for its occurrence of frequency with the winter-summer contrast reaching up to5%.The findings presented here shall help better interpret the WSAF characteristics in the long-term run as well as their impact on the regional weather and climate patterns at high spatial resolution.
基金supported by grants from the China Geological Survey(Grant Nos.1212010610102,DD20190065).
文摘The Tibetan Plateau is an important area for studying global climate change,but the answers to many scientific problems remain unknown.Here,we present new information from the lacustrine sedimentary record in the western Tibetan Plateau,related to the third most-recent glaciations.Continuous sediment data,including sporopollen,particle size,total organic carbon,mass susceptibility,CaCO_(3),CaSO_(4),BaSO_(4)contents and chronological data,were reconstructed and revealed that climate and environmental conditions obviously and distinctly changed between 600 and 700 thousand years ago.In comparison,the data obtained from the Guliya ice core in this area also corresponds to the global glacial climatic characteristics recorded in basin sediments in the eastern and southeastern regions of the plateau and to the information obtained from ice cores in the Antarctic and Arctic regions.In this study,we conclude that the main reason for the glaciations and new tectonic movement must be a geomagnetic polarity reversal 774 thousand years ago(from Matuyama to Brunhes).Indeed,the results of this study suggest that the described reversal event might have influenced the current global climate pattern and will continue to impact climatic changes in the future.
基金Under the auspices of National Natural Science Foundation of China(No.41971198)。
文摘Cross-border investment is essential for western China’s globalization.Global value chain(GVC)forms cross-border investment networks between industries in western China and overseas cities.Focusing on GVC,this study uses the social network analysis method,entropy method,multi-index comprehensive evaluation method,and quadratic assignment procedure analysis method to examine the characteristics and influencing factors of the urban networks of research and development(R&D),production,and sales formed as a result of the overseas investments of listed manufacturing companies in western China.Results showed that the three types of investment networks involved multiple industry types and multiple central cities with differentiated diversity and multicentrality.The R&D urban network’s leading sub-industries were the mechanical equipment and instruments,medicine and biological products,and metal and nonmetal industries.The destination cities were mostly those home to educational and scientific research centers.The production urban network’s leading sub-industries were the mechanical equipment,instrument,and food and beverage industries.The destination cities were mostly regional central cities in developing countries.The sales urban network’s leading sub-industries were the mechanical equipment and instrument,metal and nonmetal,and petrochemical and plastics industries.The destination cities were numerous and scattered.In addition,the R&D urban network easily formed specialized clusters,core nodes easily controlled the production urban network,and individual nodes did not easily control the sales urban network.Technological and economic system advantages greatly impacted the three network types.Considering the different influencing factors,this study suggests optimizing the institutional investment environment to narrow the institutional gap,adjusting and optimizing the investment layout to expand overseas markets,and increasing R&D funds to stimulate technological progress and overseas investments in western China.
基金This work was supported by the National Natural Science Foundation of China(Grant No:41776031)the National Key Research and Development Program of China(Grant 2018YFC1506903)+1 种基金the team project funding of scientific research innovation for universities in Guangdong province(Grant 2019KCXTF021)the program for scientific research start-up funds of Guangdong Ocean University(Grant R17051).
文摘The western North Pacific summer monsoon(WNPSM)is an important subcomponent of the Asian summer monsoon.The equatorial zonal wind(EZW)in the lower troposphere over the western Pacific may play a critical role in the evolution of the El Niño-Southern Oscillation(ENSO).The possible linkage between the EZW over the western Pacific and the offequatorial monsoonal winds associated with the WNPSM and its decadal changes have not yet been fully understood.Here,we find a non-stationary relationship between the WNPSM and the western Pacific EZW,significantly strengthening their correlation around the late 1980s/early 1990s.This observed shift in the WNPSM–EZW relationship could be explained by the changes in the related sea surface temperature(SST)configurations across the tropical oceans.The enhanced influence from the springtime tropical North Atlantic,summertime tropical central Pacific,and maritime continent SST anomalies may be working together in contributing to the recent intensified WNPSM–EZW co-variability.The observed recent strengthening of the WNPSM–EZW relationship may profoundly impact the climate system,including prompting more effective feedback from the WNPSM on subsequent ENSO evolution and bolstering a stronger biennial tendency of the WNPSM–ENSO coupled system.The results obtained herein imply that the WNPSM,EZW,ENSO,and the tropical North Atlantic SST may be closely linked within a unified climate system with a quasi-biennial rhythm occurring during recent decades,accompanied by a reinforcement of the WNPSM–ENSO interplay quite possibly triggered by enhanced tropical Pacific–Atlantic cross-basin interactions.These results highlight the importance of the tropical Atlantic cross-basin influences in shaping the spatial structure of WNPSM-related wind anomalies and the WNPSM–ENSO interaction.
