The relationship between climate change and water resources in the Tarim River was analyzed by combining the temperature,precipitation and streamflow data from 1957 to 2007 from the four headstreams of the Tarim River...The relationship between climate change and water resources in the Tarim River was analyzed by combining the temperature,precipitation and streamflow data from 1957 to 2007 from the four headstreams of the Tarim River （Aksu,Hotan,Yarkant and Kaidu rivers） in the study area.The long-term trend of the hydrological time series including temperature,precipitation and streamflow were studied using correlation analysis and partial correlations analysis.Holt double exponential smoothing was used to fit the trends between streamflow and the two climatic factors of Aksu River,Hotan River and Yarkant River.The streamflow of the main stream was forecasted by Autoregressive Integrated Moving Average Model （ARIMA） modeling by the method of time series analysis.The results show that the temperature experienced a trend of monotonic rising.The precipitation and runoff of the four headstreams of the Tarim River increased,while the inflow to the headstreams increased and the inflow into the Tarim River decreased.Changes of temperature and precipitation had a significant impact on runoff into the four headstreams of the Tarim River： the precipitation had a positive impact on water flow in the Aksu River,Hotan River and Kaidu River,while the temperature had a positive impact on water flow in the Yarkant River.The results of Holt double exponential smoothing showed that the correlation between the independent variable and dependent variable was relatively close after the model was fitted to the headstreams,of which only the runoff and temperature values of Hotan River showed a significant negative correlation.The forecasts by the ARIMA model for 50 years of annual runoff at the Allar station followed the pattern of the measured data for the same years.The short-term forecasts beyond the observed series adequately captured the pattern in the data and showed a decreasing tendency in the Tarim River flow of 3.07% every ten years.The results showed that global warming accelerated the water recharge process of the headstreams.The special hydrological characteristics of the arid area determined the significant association between streamflow and the two climatic factors studied.Strong glacier retreat is likely to bring a series of flood disasters within the study area.展开更多
Oasis stability in the lower reaches of the Tarim River was assessed at the landscape scale（including changes in landscape pattern and land use in the oasis） and at the regional scale（including the cold-island effe...Oasis stability in the lower reaches of the Tarim River was assessed at the landscape scale（including changes in landscape pattern and land use in the oasis） and at the regional scale（including the cold-island effect and NDVI of the oasis） based on the methods of landscape ecology,GIS and Remote Sensing（RS）.Thematic Mapping（TM） remote sensing images from 1990,2000 and 2009 were employed along with the related meteorological and hydrological data pertaining to the reclamation area of the oasis in the lower reaches of the Tarim River.The results indicated that landscape heterogeneity and oasis complexity increased between 1990 and 2000.The comprehensive index of the degree of land use,the average index of the cold-island effect,NDVI value and oasis stability all decreased.However,the change trends in the indices referred to above were opposite between 2000 and 2009,and oasis stability was enhanced to some extent.展开更多
Populus euphratica Oliv.is an old desert tree species that has been naturalized and invades zones along the watercourses in many arid and semiarid regions.The plant species developed some plasticity to adapt to the gr...Populus euphratica Oliv.is an old desert tree species that has been naturalized and invades zones along the watercourses in many arid and semiarid regions.The plant species developed some plasticity to adapt to the gradual environmental gradients.The aim of this study was to test the hypothesis that the changes in leaf morphology of P.euphratica reflect the adaptability of the plant to the unique environment of the lower reaches of Tarim River in China.The foliar architecture,blade epidermal and internal anatomies of P.euphratica were analyzed at different sites along the Tarim River.Compared with the abaxial surface of the leaves,their adaxial surface has more hairs,a greater stomatal density and opening,higher mesophyll proportion,and increased blade thickness,palisade width,and epidermal thickness.The long trichome of the roots found at site 6 in the Yinsu section may be an adapted structure of the plants in arid areas.The mature leaves of P.euphratica have comparatively more epidermis and cuticles,well developed palisades and more chloroplasts at different sites compared to the young leaves.Foliar morphological and anatomical variability in P.euphratica may be considered an adaptive advantage that enables leaves to develop and function in different habitats,marked by strong variations in solar radiation,air temperature,humidity and water table.展开更多
In the arid region of northwestern China(ARNC),water resources are the most critical factor restricting socioeconomic development and influencing the stability of the area’s ecological systems.The region’s complex w...In the arid region of northwestern China(ARNC),water resources are the most critical factor restricting socioeconomic development and influencing the stability of the area’s ecological systems.The region’s complex water system and unique hydrological cycle show distinctive characteristics.Moreover,the intensified hydrological cycle and extreme climatic and hydrological events resulting from global warming have led to increased uncertainty around water resources as well as heightened conflict between water supply and water demand.All of these factors are exerting growing pressures on the socioeconomic development and vulnerable ecological environment in the region.This research evaluates the impacts of climate change on water resources,hydrological processes,agricultural system,and desert ecosystems in the ARNC,and addresses some associated risks and challenges specific to this area.The temperature is rising at a rate of 0.31C per decade during 1961–2017 and hydrological processes are being significantly influenced by changes in glaciers,snow cover,and precipitation form,especially in the rivers recharged primarily by melt water.Ecosystems are also largely influenced by climate change,with the Normalized Difference Vegetation Index(NDVI)of natural vegetation exhibited an increasing trend prior to 1998,and then reversed in Xinjiang while the Hexi Corridor of Gansu showed the opposite trends.Furthermore,the desert-oasis transition zone showed a reduction in area due to the warming trend and the recent rapid expansion of irrigated area.Both the warming and intensified drought are threatening agriculture security.The present study could shed light on sustainable development in this region under climate change and provides scientific basis to the construction of the“Silk Road Economic Belt”.展开更多
The development of novel theranostic agents with outstanding diagnostic and therapeutic performances is still strongly desired in the treatment of hepatocellular carcinoma(HCC).Here,a fucoidan-modified mesoporous poly...The development of novel theranostic agents with outstanding diagnostic and therapeutic performances is still strongly desired in the treatment of hepatocellular carcinoma(HCC).Here,a fucoidan-modified mesoporous polydopamine nanoparticle dual-loaded with gadolinium iron and doxorubicin(FMPDA/Gd^(3+)/DOX)was prepared as an effective theranostic agent for magnetic resonance imaging(MRI)-guided chemo-photothermal therapy of HCC.It was found that FMPDA/Gd^(3+)/DOX had a high photothermal conversion efficiency of 33.4%and excellent T1-MRI performance with a longitudinal relaxivity(r1)value of 14.966 m M^(-1)·s^(-1).Moreover,the results suggested that FMPDA/Gd^(3+)/DOX could effectively accumulate into the tumor foci by dual-targeting the tumor-infiltrated platelets and HCC cells,which resulted from the specific interaction between fucoidan and overexpressed p-selectin receptors.The excellent tumor-homing ability and MRI-guided chemo-photothermal therapy therefore endowed FMPDA/Gd^(3+)/DOX with a strongest ability to inhibit tumor growth than the respective single treatment modality.Overall,our study demonstrated that FMPDA/Gd^(3+)/DOX could be applied as a potential nanoplatform for safe and effective cancer theranostics.展开更多
The increase in extreme precipitation(EP)may pose a serious threat to the health and safety of population in arid and semi-arid regions.The current research on the impact of EP on population in Central Asia(CA)is insu...The increase in extreme precipitation(EP)may pose a serious threat to the health and safety of population in arid and semi-arid regions.The current research on the impact of EP on population in Central Asia(CA)is insufficient and there is an urgent need for a comprehensive assessment.Hence,we opted for precipitation and temperature data under two Shared Socioeconomic Pathways(SSP2-4.5 and SSP5-8.5)from ten Global Climate Models(GCMs),which were obtained from the NASA Earth Exchange Global Daily Downscaled Projections(NEX-GDDP-CMIP6).By integrating population data in 2020 and 2050(SSP2 and SSP5),we investigated the future changes in EP and population exposure in CA under 1.5℃and 2℃global warming scenarios(GWSs).Our analysis indicates that EP in CA is projected to increase with global warming.Under the SSP5-8.5,the maximum daily precipitation(Rx1day)exhibits an average response rate to global warming of 3.58%/K(1.99-4.06%/K).With rising temperatures,an increasing number of areas and populations in CA will be impacted by EP,especially in the Fergana valley.Approximately 25%of the population(land area)in CA is exposed to Rx1day with increases of more than 8.31%(9.32%)under 1.5℃GWS and 14.18%(13.25%)under 2℃GWS.Controlling temperature rise can be effective in reducing population exposures to EP.For instance,limiting the temperature increase to 1.5℃instead of 2℃results in a 2.79%(1.75%-4.59%)reduction in population exposure to Rx1day.Finally,we found that climate change serves as the predominant factor influencing the population exposure to EP,while the role of population redistribution,although relatively minor,should not be disregarded.Particularly for prolonged drought,the role of population redistribution manifests negatively.展开更多
The content of proline in the plant bodies is closely related to the converse-succession-resistant capability of the plants. In this paper, the relationship between the proline accumulation in the bodies of Populus eu...The content of proline in the plant bodies is closely related to the converse-succession-resistant capability of the plants. In this paper, the relationship between the proline accumulation in the bodies of Populus euphratica and the change of groundwater level is analyzed by taking Popu-lus euphratica, the main community-building species of the desert riparian forests along the Tarim River, as the research object. The research results show that the accumulation of proline in the bodies of Populus euphratica is closely related to the change of groundwater level gradient under drought stress, it increases with the drawdown of groundwater level and the increase of moisture stress degree; the accumulation of proline in the bodies of Populus euphratica has two ex-tremely high points at the groundwater depth ranges of 3.64—5.14 m and 9.46—10.16 m. Combining the field investiga-tion and the analysis of the plots, it is considered that the groundwater level of 3.5—4.5 m is rational for the growth of Populus euphratica. The stress groundwater depth for the normal growth and the critical one for the survival of Popu-lus euphratica are below 4.5 m and 9—10 m respectively at the lower reaches of the Tarim River.展开更多
Using the hydrological and meteorological data in the Kaidu River Basin during 1957-2008, we simulated the hydro-climatic process by back-propagation artificial neural network （BPANN） based on wavelet analysis （WA...Using the hydrological and meteorological data in the Kaidu River Basin during 1957-2008, we simulated the hydro-climatic process by back-propagation artificial neural network （BPANN） based on wavelet analysis （WA）, and then compared the simulated results with those from a multiple linear regression （MLR）. The results show that the variation of runoff responded to regional climate change. The annual runoff （AR） was mainly affected by annual average temperature （AAT） and annual precipitation （AP）, which revealed different varia- tion patterns at five time scales. At the time scale of 32-years, AR presented a monotonically increasing trend with the similar trend of AAT and AP. But at the 2-year, 4- year, 8-year, and 16-year time-scale, AR presented non-linear variation with fluctuations of AAT and AP. Both MLR and BPANN successfully simulated the hydro- climatic process based on WA at each time scale, but the simulated effect from BPANN is better than that from MLR.展开更多
The aim of this study was to analyze the effects of climate fluctuations on runoff in the headwater region of the Kaidu River in northwestern China. For this purpose, precipitation and potential evaporation （PET） da...The aim of this study was to analyze the effects of climate fluctuations on runoff in the headwater region of the Kaidu River in northwestern China. For this purpose, precipitation and potential evaporation （PET） data from 5 meteorological stations and the runoff depth data from the Dashankou hydrological station in the headwater region of the Kaidu River from 1960 to 2009 were collected, then the trends and abrupt changes of precipitation, PET and runoff depth were analyzed by means of Mann-Kendall test （M-K test） and Mann-Kendall-Sneyers test （M-K-S test）, respectively. The runoff model driven by precipitation and PET was developed in this work and the sensitivity of runoff to climate fluctuation was simulated under different scenarios. Results showed that the annual precipitation and runoff depth both exhibited an increasing trend over the periods 1960-2009; however, this is not the case for the annual PET. The abrupt changes for annual precipitation, PETand runoff depth all occurred in the early 1990s. The established driving model could well reflect the compli- cated nonlinear relationship among runoff depth, precipitation and PET. The sensitivity analysis indicated that the precipitation had a positive effect on the runoff depth, opposite to what were observed between PET and runoff, and the runoff depth was more sensitive to precipitation than to PET in the headwater region of the Kaidu River.展开更多
High Mountain Asia (HMA), known as Earth's "Third Pole" and"Asia's water tower",. is the largest glacier and snow reservoir onEarth except for the polar ice sheets (Text S1 and Fig. S1 onli...High Mountain Asia (HMA), known as Earth's "Third Pole" and"Asia's water tower",. is the largest glacier and snow reservoir onEarth except for the polar ice sheets (Text S1 and Fig. S1 online)。Snow is an important component of the HMA cryosphere, and itsvariability directly affects the water and energy balances in theregion [1,2] The average warming rate in the HMA region in recentdecades is approximately twofold higher than the average warm-ing rate in China and the world in the same period. The climatologyand trends of snow cover in the HMA have been investigated basedon station and satellite observations. However, these methodshave some limitations, resulting in large uncertainties or limita-tions in assessing long-term snow cover changes in the HMA.Snowpack changes in the HMA region analyzed over a short timeseries may also lead to conclusions that are inconsistent with con-ventional assertions. Several studies of the temporal and spatialvariability of snow cover in the HMA region using short-termModerate Resolution lmaging Spectroradiometer data revealed nosignificant shrinkage in the snow cover area (SCA) [3].展开更多
Central Asia,located in the hinterland of the Eurasian continent,is characterized with sparse rainfall,frequent droughts and low water use efficiency.Limited water resources have become a key factor restricting the su...Central Asia,located in the hinterland of the Eurasian continent,is characterized with sparse rainfall,frequent droughts and low water use efficiency.Limited water resources have become a key factor restricting the sustainable development of this region.Accurately assessing the efficiency of water resources utilization is the first step to achieve the UN Sustainable Development Goals(SDGs)in Central Asia.However,since the collapse of the Soviet Union,the evalua-tion of water use efficiency is difficult due to low data availability and poor consistency.To fill this gap,this paper developed a Water Use Efficiency dataset(WUE)based on the Moderate Resolution Imaging Spectroradiometer(MODIS)Gross Primary Production(GPP)data and the MODIS evapotranspiration(ET)data.The WUE dataset ranges from 2000 to 2019 with a spatial resolution of 500 m.The agricultural WUE was then extracted based on the Global map of irrigated areas and MODIS land use map.As a complementary,the water use amount per GDP was estimated for each country.The present dataset could reflect changes in water use efficiency of agriculture and other sectors.展开更多
It is of great significance to quantitatively assess the impact of mountain precipitation on inland river runoff in data scarce regions.Based on the corrected TRMM precipitation and runoff data,a variety of statistica...It is of great significance to quantitatively assess the impact of mountain precipitation on inland river runoff in data scarce regions.Based on the corrected TRMM precipitation and runoff data,a variety of statistical methods were used to identify which areas of precipitation have an important impact on runoff in the Hotan River Basin,and to evaluate the effects that precipitation changes have on runoff at low,mid,high,and extremely high altitudes of mountainous areas.The results showed that:1)From 1998 to 2015,the annual runoff showed a fluctuating upward trend with a rate of 11.21×10^8 m^3/10 a(P<0.05).Runoff in every season also had an increasing trend,with summer runoff the most significant at a rate of 6.09×10^8 m^3/10 a.2)The annual runoff and precipitation changes had certain synchronization,with a correlation coefficient of 0.45(P<0.05).Among them,the correlations between precipitation and runoff changes were highest at low and mid-altitudes,with coefficients of 0.62 and 0.55,respectively(P<0.05).3)65.95%of the regional precipitation at low altitudes and 48.34%at high altitudes were significantly correlated with runoff(P<0.05),while only 38.84%and 26.58%of regional precipitation levels at mid-and extremely high altitudes were significantly correlated with runoff.4)The annual precipitation change in the basin was 1%,which would cause the annual runoff to change by 0.24%.In 1998-2015,the change of annual runoff caused by precipitation change at high altitudes was largest at a rate of−6.01%;the change rates of annual runoff caused by precipitation change in the low,mid-,and extremely high altitudes were−3.66%,−3.62%,and−3.67%,respectively.The results have significant scientific guidance for water resource management in arid basins.展开更多
Comprehensive evaluation of the characteristics and mechanisms of droughts is of great significance to drought risk prediction and prevention.The 3-monthly scale Standardized Runoff Index(SRI-3)and 3-monthly scale Sta...Comprehensive evaluation of the characteristics and mechanisms of droughts is of great significance to drought risk prediction and prevention.The 3-monthly scale Standardized Runoff Index(SRI-3)and 3-monthly scale Standardized Precipitation Evapotranspiration Index(SPEI-3)were employed herein to characterize hydrological and meteorological droughts,respectively,within the four upper subbasins of the Tarim River Basin(TRB)during 1961-2015.The propagation of droughts was also evaluated.The hydrological drought duration(Dd)and drought severity(Ds)were determined by Run theory,and Copula functions were adopted to investigate the hydrological drought probabilities and return periods.The propagation relationships of hydrological and meteorological droughts were assessed.The results indicated that:1)hydrological drought index(SRI-3)significantly increased in the TRB from 1961 to 2015;the increase was most significant in winter.Meteorological drought index(SPEI-3)exhibited a weak upward trend through time;2)the characteristics of hydrological droughts varied between the subbasins;increases in the SRI were most significant in the Yarkand and Hotan Rivers,whereas the Dd and Ds of hydrological droughts were higher in the Kaidu and Yarkand Rivers;3)Frank Copula was the most closely fitted Copula function in the four subbasins of the TRB and yielded average drought return periods of 4.86,4.78,3.72,and 5.57 years for the Kaidu,Aksu,Yarkand,and Hotan River Basins,respectively.The return periods in the four subbasins were generally less than 10 years from 1961 to 2015;4)a cross wavelet transform(XWT)exhibited a significant positive correlation between hydrological and meteorological droughts,except for the Yarkand River Basin,which exhibited a significant negative correlation.Besides,the propagation relationship of meteorological droughts to hydrological droughts showed remarkable seasonal variations.展开更多
基金supported by the National Basic Research Program of China (2010CB951003)
文摘The relationship between climate change and water resources in the Tarim River was analyzed by combining the temperature,precipitation and streamflow data from 1957 to 2007 from the four headstreams of the Tarim River （Aksu,Hotan,Yarkant and Kaidu rivers） in the study area.The long-term trend of the hydrological time series including temperature,precipitation and streamflow were studied using correlation analysis and partial correlations analysis.Holt double exponential smoothing was used to fit the trends between streamflow and the two climatic factors of Aksu River,Hotan River and Yarkant River.The streamflow of the main stream was forecasted by Autoregressive Integrated Moving Average Model （ARIMA） modeling by the method of time series analysis.The results show that the temperature experienced a trend of monotonic rising.The precipitation and runoff of the four headstreams of the Tarim River increased,while the inflow to the headstreams increased and the inflow into the Tarim River decreased.Changes of temperature and precipitation had a significant impact on runoff into the four headstreams of the Tarim River： the precipitation had a positive impact on water flow in the Aksu River,Hotan River and Kaidu River,while the temperature had a positive impact on water flow in the Yarkant River.The results of Holt double exponential smoothing showed that the correlation between the independent variable and dependent variable was relatively close after the model was fitted to the headstreams,of which only the runoff and temperature values of Hotan River showed a significant negative correlation.The forecasts by the ARIMA model for 50 years of annual runoff at the Allar station followed the pattern of the measured data for the same years.The short-term forecasts beyond the observed series adequately captured the pattern in the data and showed a decreasing tendency in the Tarim River flow of 3.07% every ten years.The results showed that global warming accelerated the water recharge process of the headstreams.The special hydrological characteristics of the arid area determined the significant association between streamflow and the two climatic factors studied.Strong glacier retreat is likely to bring a series of flood disasters within the study area.
基金supported by the National Basic Research Program of China (2010CB951003)National Natural Science Foundation of China (40901061)+1 种基金Key Topics in Innovation Engineering of the Chinese Academy of Sciences (KZCX2-YW-Q10-3-4)Western Talent Cultivation Plan(XBBS200907)
文摘Oasis stability in the lower reaches of the Tarim River was assessed at the landscape scale（including changes in landscape pattern and land use in the oasis） and at the regional scale（including the cold-island effect and NDVI of the oasis） based on the methods of landscape ecology,GIS and Remote Sensing（RS）.Thematic Mapping（TM） remote sensing images from 1990,2000 and 2009 were employed along with the related meteorological and hydrological data pertaining to the reclamation area of the oasis in the lower reaches of the Tarim River.The results indicated that landscape heterogeneity and oasis complexity increased between 1990 and 2000.The comprehensive index of the degree of land use,the average index of the cold-island effect,NDVI value and oasis stability all decreased.However,the change trends in the indices referred to above were opposite between 2000 and 2009,and oasis stability was enhanced to some extent.
基金funded by the National Natural Science Foundation of China (31060062 and 11014010)the Shihezi University Program (Q9yy200814)
文摘Populus euphratica Oliv.is an old desert tree species that has been naturalized and invades zones along the watercourses in many arid and semiarid regions.The plant species developed some plasticity to adapt to the gradual environmental gradients.The aim of this study was to test the hypothesis that the changes in leaf morphology of P.euphratica reflect the adaptability of the plant to the unique environment of the lower reaches of Tarim River in China.The foliar architecture,blade epidermal and internal anatomies of P.euphratica were analyzed at different sites along the Tarim River.Compared with the abaxial surface of the leaves,their adaxial surface has more hairs,a greater stomatal density and opening,higher mesophyll proportion,and increased blade thickness,palisade width,and epidermal thickness.The long trichome of the roots found at site 6 in the Yinsu section may be an adapted structure of the plants in arid areas.The mature leaves of P.euphratica have comparatively more epidermis and cuticles,well developed palisades and more chloroplasts at different sites compared to the young leaves.Foliar morphological and anatomical variability in P.euphratica may be considered an adaptive advantage that enables leaves to develop and function in different habitats,marked by strong variations in solar radiation,air temperature,humidity and water table.
基金supported by the National Key Research and Development Program(2019YFA0606902)the National Natural Science Foundation of China(U1903208)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(2019431).
文摘In the arid region of northwestern China(ARNC),water resources are the most critical factor restricting socioeconomic development and influencing the stability of the area’s ecological systems.The region’s complex water system and unique hydrological cycle show distinctive characteristics.Moreover,the intensified hydrological cycle and extreme climatic and hydrological events resulting from global warming have led to increased uncertainty around water resources as well as heightened conflict between water supply and water demand.All of these factors are exerting growing pressures on the socioeconomic development and vulnerable ecological environment in the region.This research evaluates the impacts of climate change on water resources,hydrological processes,agricultural system,and desert ecosystems in the ARNC,and addresses some associated risks and challenges specific to this area.The temperature is rising at a rate of 0.31C per decade during 1961–2017 and hydrological processes are being significantly influenced by changes in glaciers,snow cover,and precipitation form,especially in the rivers recharged primarily by melt water.Ecosystems are also largely influenced by climate change,with the Normalized Difference Vegetation Index(NDVI)of natural vegetation exhibited an increasing trend prior to 1998,and then reversed in Xinjiang while the Hexi Corridor of Gansu showed the opposite trends.Furthermore,the desert-oasis transition zone showed a reduction in area due to the warming trend and the recent rapid expansion of irrigated area.Both the warming and intensified drought are threatening agriculture security.The present study could shed light on sustainable development in this region under climate change and provides scientific basis to the construction of the“Silk Road Economic Belt”.
基金supported by the National Key Research and Development projects intergovernmental cooperation in science and technology of China(2018YFE0126900)National Natural Science Foundation of China(82072025 and82072026)+2 种基金Zhejiang Provincial Natural Science Foundation(LQ21H180003)Key R&D Program of Lishui City(2021ZDYF12)Medical Health Science and Technology Project of Zhejiang Provincial Health Commission(2022RC088)。
文摘The development of novel theranostic agents with outstanding diagnostic and therapeutic performances is still strongly desired in the treatment of hepatocellular carcinoma(HCC).Here,a fucoidan-modified mesoporous polydopamine nanoparticle dual-loaded with gadolinium iron and doxorubicin(FMPDA/Gd^(3+)/DOX)was prepared as an effective theranostic agent for magnetic resonance imaging(MRI)-guided chemo-photothermal therapy of HCC.It was found that FMPDA/Gd^(3+)/DOX had a high photothermal conversion efficiency of 33.4%and excellent T1-MRI performance with a longitudinal relaxivity(r1)value of 14.966 m M^(-1)·s^(-1).Moreover,the results suggested that FMPDA/Gd^(3+)/DOX could effectively accumulate into the tumor foci by dual-targeting the tumor-infiltrated platelets and HCC cells,which resulted from the specific interaction between fucoidan and overexpressed p-selectin receptors.The excellent tumor-homing ability and MRI-guided chemo-photothermal therapy therefore endowed FMPDA/Gd^(3+)/DOX with a strongest ability to inhibit tumor growth than the respective single treatment modality.Overall,our study demonstrated that FMPDA/Gd^(3+)/DOX could be applied as a potential nanoplatform for safe and effective cancer theranostics.
基金supported by the Tienshan Talent Program in Xinjiang(Grant No.2023TSYCLJ0050)the National Natural Science Foundation of China(Grant No.42122004)the West Light Founda-tion of the Chinese Academy of Sciences(Grant No.xbzg-zdsys-202208).
文摘The increase in extreme precipitation(EP)may pose a serious threat to the health and safety of population in arid and semi-arid regions.The current research on the impact of EP on population in Central Asia(CA)is insufficient and there is an urgent need for a comprehensive assessment.Hence,we opted for precipitation and temperature data under two Shared Socioeconomic Pathways(SSP2-4.5 and SSP5-8.5)from ten Global Climate Models(GCMs),which were obtained from the NASA Earth Exchange Global Daily Downscaled Projections(NEX-GDDP-CMIP6).By integrating population data in 2020 and 2050(SSP2 and SSP5),we investigated the future changes in EP and population exposure in CA under 1.5℃and 2℃global warming scenarios(GWSs).Our analysis indicates that EP in CA is projected to increase with global warming.Under the SSP5-8.5,the maximum daily precipitation(Rx1day)exhibits an average response rate to global warming of 3.58%/K(1.99-4.06%/K).With rising temperatures,an increasing number of areas and populations in CA will be impacted by EP,especially in the Fergana valley.Approximately 25%of the population(land area)in CA is exposed to Rx1day with increases of more than 8.31%(9.32%)under 1.5℃GWS and 14.18%(13.25%)under 2℃GWS.Controlling temperature rise can be effective in reducing population exposures to EP.For instance,limiting the temperature increase to 1.5℃instead of 2℃results in a 2.79%(1.75%-4.59%)reduction in population exposure to Rx1day.Finally,we found that climate change serves as the predominant factor influencing the population exposure to EP,while the role of population redistribution,although relatively minor,should not be disregarded.Particularly for prolonged drought,the role of population redistribution manifests negatively.
文摘The content of proline in the plant bodies is closely related to the converse-succession-resistant capability of the plants. In this paper, the relationship between the proline accumulation in the bodies of Populus euphratica and the change of groundwater level is analyzed by taking Popu-lus euphratica, the main community-building species of the desert riparian forests along the Tarim River, as the research object. The research results show that the accumulation of proline in the bodies of Populus euphratica is closely related to the change of groundwater level gradient under drought stress, it increases with the drawdown of groundwater level and the increase of moisture stress degree; the accumulation of proline in the bodies of Populus euphratica has two ex-tremely high points at the groundwater depth ranges of 3.64—5.14 m and 9.46—10.16 m. Combining the field investiga-tion and the analysis of the plots, it is considered that the groundwater level of 3.5—4.5 m is rational for the growth of Populus euphratica. The stress groundwater depth for the normal growth and the critical one for the survival of Popu-lus euphratica are below 4.5 m and 9—10 m respectively at the lower reaches of the Tarim River.
文摘Using the hydrological and meteorological data in the Kaidu River Basin during 1957-2008, we simulated the hydro-climatic process by back-propagation artificial neural network （BPANN） based on wavelet analysis （WA）, and then compared the simulated results with those from a multiple linear regression （MLR）. The results show that the variation of runoff responded to regional climate change. The annual runoff （AR） was mainly affected by annual average temperature （AAT） and annual precipitation （AP）, which revealed different varia- tion patterns at five time scales. At the time scale of 32-years, AR presented a monotonically increasing trend with the similar trend of AAT and AP. But at the 2-year, 4- year, 8-year, and 16-year time-scale, AR presented non-linear variation with fluctuations of AAT and AP. Both MLR and BPANN successfully simulated the hydro- climatic process based on WA at each time scale, but the simulated effect from BPANN is better than that from MLR.
文摘The aim of this study was to analyze the effects of climate fluctuations on runoff in the headwater region of the Kaidu River in northwestern China. For this purpose, precipitation and potential evaporation （PET） data from 5 meteorological stations and the runoff depth data from the Dashankou hydrological station in the headwater region of the Kaidu River from 1960 to 2009 were collected, then the trends and abrupt changes of precipitation, PET and runoff depth were analyzed by means of Mann-Kendall test （M-K test） and Mann-Kendall-Sneyers test （M-K-S test）, respectively. The runoff model driven by precipitation and PET was developed in this work and the sensitivity of runoff to climate fluctuation was simulated under different scenarios. Results showed that the annual precipitation and runoff depth both exhibited an increasing trend over the periods 1960-2009; however, this is not the case for the annual PET. The abrupt changes for annual precipitation, PETand runoff depth all occurred in the early 1990s. The established driving model could well reflect the compli- cated nonlinear relationship among runoff depth, precipitation and PET. The sensitivity analysis indicated that the precipitation had a positive effect on the runoff depth, opposite to what were observed between PET and runoff, and the runoff depth was more sensitive to precipitation than to PET in the headwater region of the Kaidu River.
基金supported by the National Natural Science Foundation of China(42101054 and 42171126)the Project of Tianshan Innovation Team in Xinjiang(2021D14015)+1 种基金the Xinjiang Talent Programthe Youth Innovation Promotion Association of the Chinese Academy of Sciences。
文摘High Mountain Asia (HMA), known as Earth's "Third Pole" and"Asia's water tower",. is the largest glacier and snow reservoir onEarth except for the polar ice sheets (Text S1 and Fig. S1 online)。Snow is an important component of the HMA cryosphere, and itsvariability directly affects the water and energy balances in theregion [1,2] The average warming rate in the HMA region in recentdecades is approximately twofold higher than the average warm-ing rate in China and the world in the same period. The climatologyand trends of snow cover in the HMA have been investigated basedon station and satellite observations. However, these methodshave some limitations, resulting in large uncertainties or limita-tions in assessing long-term snow cover changes in the HMA.Snowpack changes in the HMA region analyzed over a short timeseries may also lead to conclusions that are inconsistent with con-ventional assertions. Several studies of the temporal and spatialvariability of snow cover in the HMA region using short-termModerate Resolution lmaging Spectroradiometer data revealed nosignificant shrinkage in the snow cover area (SCA) [3].
基金was funded by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA19030204)the Key Research Program of the Chinese Academy of Sciences(ZDRW-ZS-2019-3).
文摘Central Asia,located in the hinterland of the Eurasian continent,is characterized with sparse rainfall,frequent droughts and low water use efficiency.Limited water resources have become a key factor restricting the sustainable development of this region.Accurately assessing the efficiency of water resources utilization is the first step to achieve the UN Sustainable Development Goals(SDGs)in Central Asia.However,since the collapse of the Soviet Union,the evalua-tion of water use efficiency is difficult due to low data availability and poor consistency.To fill this gap,this paper developed a Water Use Efficiency dataset(WUE)based on the Moderate Resolution Imaging Spectroradiometer(MODIS)Gross Primary Production(GPP)data and the MODIS evapotranspiration(ET)data.The WUE dataset ranges from 2000 to 2019 with a spatial resolution of 500 m.The agricultural WUE was then extracted based on the Global map of irrigated areas and MODIS land use map.As a complementary,the water use amount per GDP was estimated for each country.The present dataset could reflect changes in water use efficiency of agriculture and other sectors.
基金This research is supported by the National Natural Science Foundation of China(Grant Nos.U1903208 and 41501211).
文摘It is of great significance to quantitatively assess the impact of mountain precipitation on inland river runoff in data scarce regions.Based on the corrected TRMM precipitation and runoff data,a variety of statistical methods were used to identify which areas of precipitation have an important impact on runoff in the Hotan River Basin,and to evaluate the effects that precipitation changes have on runoff at low,mid,high,and extremely high altitudes of mountainous areas.The results showed that:1)From 1998 to 2015,the annual runoff showed a fluctuating upward trend with a rate of 11.21×10^8 m^3/10 a(P<0.05).Runoff in every season also had an increasing trend,with summer runoff the most significant at a rate of 6.09×10^8 m^3/10 a.2)The annual runoff and precipitation changes had certain synchronization,with a correlation coefficient of 0.45(P<0.05).Among them,the correlations between precipitation and runoff changes were highest at low and mid-altitudes,with coefficients of 0.62 and 0.55,respectively(P<0.05).3)65.95%of the regional precipitation at low altitudes and 48.34%at high altitudes were significantly correlated with runoff(P<0.05),while only 38.84%and 26.58%of regional precipitation levels at mid-and extremely high altitudes were significantly correlated with runoff.4)The annual precipitation change in the basin was 1%,which would cause the annual runoff to change by 0.24%.In 1998-2015,the change of annual runoff caused by precipitation change at high altitudes was largest at a rate of−6.01%;the change rates of annual runoff caused by precipitation change in the low,mid-,and extremely high altitudes were−3.66%,−3.62%,and−3.67%,respectively.The results have significant scientific guidance for water resource management in arid basins.
基金supported by the National Natural Science Foundation of China(Grant No.U1903208)Guangdong Foundation for Program of Science and Technology Research(Nos.2020B1111530001 and 2019QN01L682)the GDAS Special Project of Science and Technology Development(Nos.2020GDASYL-20200102013 and 2020GDASYL-20200301003).
文摘Comprehensive evaluation of the characteristics and mechanisms of droughts is of great significance to drought risk prediction and prevention.The 3-monthly scale Standardized Runoff Index(SRI-3)and 3-monthly scale Standardized Precipitation Evapotranspiration Index(SPEI-3)were employed herein to characterize hydrological and meteorological droughts,respectively,within the four upper subbasins of the Tarim River Basin(TRB)during 1961-2015.The propagation of droughts was also evaluated.The hydrological drought duration(Dd)and drought severity(Ds)were determined by Run theory,and Copula functions were adopted to investigate the hydrological drought probabilities and return periods.The propagation relationships of hydrological and meteorological droughts were assessed.The results indicated that:1)hydrological drought index(SRI-3)significantly increased in the TRB from 1961 to 2015;the increase was most significant in winter.Meteorological drought index(SPEI-3)exhibited a weak upward trend through time;2)the characteristics of hydrological droughts varied between the subbasins;increases in the SRI were most significant in the Yarkand and Hotan Rivers,whereas the Dd and Ds of hydrological droughts were higher in the Kaidu and Yarkand Rivers;3)Frank Copula was the most closely fitted Copula function in the four subbasins of the TRB and yielded average drought return periods of 4.86,4.78,3.72,and 5.57 years for the Kaidu,Aksu,Yarkand,and Hotan River Basins,respectively.The return periods in the four subbasins were generally less than 10 years from 1961 to 2015;4)a cross wavelet transform(XWT)exhibited a significant positive correlation between hydrological and meteorological droughts,except for the Yarkand River Basin,which exhibited a significant negative correlation.Besides,the propagation relationship of meteorological droughts to hydrological droughts showed remarkable seasonal variations.
