China has launched her first ocean color satellite HY-1A on May 15, 2002 since American ocean color satellite SeaSTAR was on the orbit in 1997. First, the properties and characteristics of HY-1A are briefly introduced...China has launched her first ocean color satellite HY-1A on May 15, 2002 since American ocean color satellite SeaSTAR was on the orbit in 1997. First, the properties and characteristics of HY-1A are briefly introduced; second, the quality and availability are evaluated by means of the complex signal noise ratio ( CSNR) which is simulated theoretically; third, the received HY-1A data are compared with SeaSTAR data to understand the accuracy of radiance measurement by the HY-1A; finally, the remote sensing products of ocean color and temperature are mapped to study the application potentiality of HY-1A. The results show that the HY-1A has its latent capability for the application of marine environment detection, the management and protection of marine resources, and the national rights and interests. Meanwhile some suggestions are proposed to modify the next ocean satellite.展开更多
This study addresses the comparative carbon emissions of different transportation modes within a unified evaluation framework,focusing on their carbon footprints from inception to disposal.Specifically,the entire life...This study addresses the comparative carbon emissions of different transportation modes within a unified evaluation framework,focusing on their carbon footprints from inception to disposal.Specifically,the entire life cycle carbon emissions of High-Speed Rail(HSR),battery electric vehicles,conventional internal combustion engine vehicles,battery electric buses,and conventional internal combustion engine buses are analyzed.The life cycle is segmented into vehicle manufacturing,fuel or electricity production,operational,and dismantlingrecycling stages.This analysis is applied to the Beijing-Tianjin intercity transportation system to explore emission reduction strategies.Results indicate that HSR demonstrates significant carbon emission reduction,with an intensity of only 24%-32% compared to private vehicles and 47%-89% compared to buses.Notably,HSR travel for Beijing-Tianjin intercity emits only 24% of private vehicle emissions,demonstrating the emission reduction benefits of transportation structure optimization.Additionally,predictive modeling reveals the potential for carbon emission reduction through energy structure optimization,providing a guideline for the development of effective transportation management systems.展开更多
The Jurassic in the northern Qaidam basin is an independent petroleum system.To find high－ quality source rock is the key problem in exploration.The result of plate tectonics research shows that the Jurassic basin ha...The Jurassic in the northern Qaidam basin is an independent petroleum system.To find high－ quality source rock is the key problem in exploration.The result of plate tectonics research shows that the Jurassic basin had been formed in an extensional tectonic stress field after the Indo－ China movement along northwest and northeast directions.It belongs to a kind of compound fault subsidence.The area,where the different direction subsidences overlapped,is the oil－ generating center,and also is the favourable exploration target.展开更多
Objective:Natural products of plant origin are potential source of novel antimicrobial and antioxidative agents.Thottea siliquosa(Lam.)Ding Hou.(T.siliquosa).A medicinal herb used by local tribals for treating various...Objective:Natural products of plant origin are potential source of novel antimicrobial and antioxidative agents.Thottea siliquosa(Lam.)Ding Hou.(T.siliquosa).A medicinal herb used by local tribals for treating various ailments.The present study aims at the phytochemical screening,GC-MS analysis,in vitro antibacterial activity and antioxidant potentiality of root and leaf extracts of T.siliquosa.Methods:Hot continuous Soxhlct extraction,GC-MS analysis,antibacterial analysis by disc diffusion,microdilution assay and antioxidant potentialities by hydroxyl radical and nitric oxide radical scavenging.The data was statistically analyzed.Results:Phytochemical screening of the ethyl acetate and methanolic extract of leaf and root revealed the presence of phenols,alkaloids,tannins and saponin.The extract revealed a pool of phytochemicals by comparison with authentic standards from spectral library.Both the extracts has shown their broad spectrum of inhibition against the selected bacteria Staphylococcus aureus,Escherichia coli,Pseudomonas aeruginosa and Klebsiella pneumonia compared with standard antibiotic drug streptomycin.The extracts showed antioxidant activity by scavenging of free radicals such as hydroxyl and nitric oxide.The IC_(50)values of the ethyl acetate extracts leaf and root and standard in this assay were I67.5±0.67,99.4±1.2,192±2.5μg/mL respectively.Similarly those methanolic extracts of leaf and root were 269.5±0.89 and 289.1±2.66μg/mL respectively.Similarly,ethyl acetate and methanolic extracts also caused a moderate dose-dependent inhibition of nitric oxide with an IC_(50)range 65.5±1.55 to 148±3.09μg/mL.The inhibitory activities were found to be dose dependent.Conclusion:The present study provides evidence that ethyl acetate and methanol extract of leaf and root of T.siliquosa are potential source of natural antioxidants and bactericidal nature.It is essential that research should continue to isolate and purify the bio active components of this natural plant and use in drug discovery and development.展开更多
A series of comparative studies was carried out on the genetic effects of 25 alien cytoplasms of wheat on the growth potential, heading stage, fertility, resistance against diseases, important agronomic traits and its...A series of comparative studies was carried out on the genetic effects of 25 alien cytoplasms of wheat on the growth potential, heading stage, fertility, resistance against diseases, important agronomic traits and its heterosis of 125 nuclei-cytoplasmic hybrids of wheat. The results indicated that there were clearly effects of alien cytoplasms on some characteristics, but the nucleus still exerted main effect on other characteristics. The effect of interactions between nucleus and cytoplasm was comparative obvious in some combination. Consequently, when we utilize the effects of alien cytoplasms, we should pay full attention to the facts such as the characteristic to be improved, the effects of cytoplasm, nucleus, the nucleus-cytoplasm interactions on that characteristics. From the preliminary studies, we believed that the cytoplasmic types of M0, S1, Sv, D2, D and B, and the nucleo-cytoplasmic hybrids of (Ae. sharonensis)-B174, (Ae. squarrosa)-352-35 (Ae. cylindrica)-352-35, (Ae. cylindria)-E EN-1, (Ae. cylindrica)-NPFP, and (Ae. speltoides)-352-35 would have some utilization potentiality in cultivar improvement.展开更多
The research was elaborated in Kafr El-Dawar area (Egypt northern region) to study the availability of the soil plant nutrients. The research introduced three parameters to comprehensively and carefully describe the a...The research was elaborated in Kafr El-Dawar area (Egypt northern region) to study the availability of the soil plant nutrients. The research introduced three parameters to comprehensively and carefully describe the availability of the soil plant nutrients: potentiality, gradient and anisotropy. Potentiality defines the categories of soil ability to supply plant nutrients;meanwhile gradient expresses the increasing rate of the availability of the soil plant nutrients. The gradient anisotropy refers to the directions or orientation of the increasing rate of the availability of the soil plant nutrients. The introduced parameters enabled to spatially study the availability of the soil plant nutrients. Analytical data, of soil available phosphorus (P), indicated that P ranged from 0.2 ppm to 11.4 ppm to locate all studied soil samples into the low class of the soil nutritional P ability. This was not the case of available potassium (K), where the soil samples were distributed into three available K soil categories: medium, high, and very high. GIS map of soil P nutritional potentiality for plant (potato), displayed the soil studied area in one category, as low P soil nutritional potentiality to coincide with the analytical data classification. Contrary, the K map classified the soil studied area into three categories of soil K nutritional potentiality: medium, high and excessive. This obviously referred that the individual determination of soil K nutritional potentiality is misleading for interpretation of soil tests because it does care of the spatial distribution of soil available K. Nearly, all soil samples had high available micronutrients that they were located in the high category in both classification of analytical data and GIS maps. GIS gradient maps of the soil available plant nutrients referred that the soil plant nutrients, exception of K, had two gradients: non increasing-slight increasing and build up. Gradient of soil available potassium was classified into four classes: non increasing-slight increasing, build up, moderately increasing and hike. Regardless potassium case, the non increasing-slight increasing gradient class dominated the others. GIS maps of anisotropy soil availability of macronutrients (P and K) generally showed that their gradients mainly increased in two directions: north and south. The incasing directions of soil availability of micronutrients coincided with that of the macronutrients.展开更多
Based on the groundwater resources evaluation, the groundwater exploitation potentiality evaluation is aiming at providing references for management, planning and development of groundwater. Traditional evaluation met...Based on the groundwater resources evaluation, the groundwater exploitation potentiality evaluation is aiming at providing references for management, planning and development of groundwater. Traditional evaluation methods mainly adopted individual indicator as a method which cannot fully reflect the affecting factors of the groundwater exploitation potential in a scientific way. The idea that the spatial distribution and dynamic change of groundwater is not only affected by socio-economic development and exploitation technology but also influenced by its regulation is coincided with the niche theory. This paper has preliminarily applied the niche theory to groundwater exploitation potential analysis, and proposed the concept of groundwater niche as well as its related definition, connotation and calculation formula. Meanwhile, by taking the Hebei Plain as an example, the article has made an evaluation of groundwater exploitation potentiality and a contrast with the results of the traditional evaluation methods on the construction of groundwater niche index system, and then verified the feasibility and rationality of this index system. It turns out that, it is truly comprehensive, scientific and rational to make groundwater niche calculation and exploitation potential analysis by using the evaluation index system. Niche theory has provided a new and fundamental attempt for the analysis and competition strategy for the groundwater exploitation potentiality evaluation.展开更多
Objective: To assess the developing potentiality of mouse morula produced in vitro or in the after vitrification and to evaluate the effect of one-step and two-step vitrification methods. Method: Mouse morula produced...Objective: To assess the developing potentiality of mouse morula produced in vitro or in the after vitrification and to evaluate the effect of one-step and two-step vitrification methods. Method: Mouse morula produced in for and in the were vitrified in the solution containing ethylene glycol, Ficoll and sucrose (EFS solution) with one-step and two-step methods. The developing potential and status of the pellucid zona in vitified mouse morula were assessed. Results: The percentages of morula developed into blastocyst stage were 81. 8% and 82.4%, 97. 3% and 98.4%, respectively, after one-step and two-step exposure of in vitro morula or in vivo morula to EFS solution alone, which did not show significant difference compared to their controls (P > 0. 05). The percentage of in vitro morula developed into blastocyst vitrified by onestep method was significantly lower than that by two-step method and coned (P < 0.05, 70.6% vs 81 .3%; 70.6% vs 83 .6%, respectively). However, there was no significant difference between blastocyst rates of in vivo morula vitrified by one-step and two-step methods (P>0.05, 93. 1% us 95.7%). No rupture of pellucid zona was observed in all thawed morula after one-step and two-step vitrification, irrespective of in vitro morula or in vivo morula. Conclusion: Morula produced in vitro and in vivo after vitrification may maintain high survival rate and developing potential. Two-step vitrification method with EFS solution is suitable for in vitro morula, which can improve the developing potential of in vitro morula. Onestep and two-step vitrification method have no detrimennd effect on the developing potential of in vivo morula.展开更多
Scaling-up agroforestry area in various forms is a scientific path towards achieving various sustainable development goals(SDGs),especially improving livelihood,reducing poverty,conserving environment and biodiversity...Scaling-up agroforestry area in various forms is a scientific path towards achieving various sustainable development goals(SDGs),especially improving livelihood,reducing poverty,conserving environment and biodiversity,and transforming climate change.In this study,the effort was made to investigate the land potentiality for agroforestry at the district level in Jharkhand State,India by applying geographic information system(GIS)modeling technology using climate(temperature and precipitation),topography(slope and elevation),ecology(percent tree cover and normalized difference vegetation index(NDVI)),and social economics(poverty rate and tribal dominance)factors.The results revealed that six districts of Jharkhand State had agroforestry potential greater than 60.00%.The highest agroforestry suitability was found in Simdega District(78.20%),followed by Pakur(76.25%),West Singhbhum(72.70%),Dumka(68.84%),Sahibganj(64.63%),and Godda(63.43%)districts.Additionally,we identified 513 out of 32,620 villages of Jharkhand State potentially suitable(agroforestry suitability≥80.00%)for agroforestry with the objective of life improvement among marginalized society.Under the outside forest area,8.58%of the total geographical land of Jharkhand State was wasteland,much of which was found suitable for agroforestry practices.The agroforestry setups in those wastelands can absorb 637 t carbon annually in long run and can provide direct economic benefits to the locals besides additional income for carbon emission reduction.This study concluded that Jharkhand State has plenty of high potential land for agroforestry,and adoption of agroforestry at the village level must be given high priority.This study could guide the nodal authorities to prepare appropriate strategies for scaling the tree cover in agroforestry systems in village-level landscape planning which needs policy attention and investment for achieving 9 out of the 17 SDGs.展开更多
To identify the potential groundwater bearing zones for future groundwater resources development of the study area, an investigation has been made using lithology, groundwater monitoring and elevation data. The strati...To identify the potential groundwater bearing zones for future groundwater resources development of the study area, an investigation has been made using lithology, groundwater monitoring and elevation data. The stratigraphic cross-sections of the area reveal six distinct hydrostratigraphic features viz. clay-silt-sand, fine sand, fine to medium sand, medium sand, medium to coarse sand and coarse sand. On the basis of lithological information, the groundwater bearing zone of the area has been divided into two main hydrostratigraphic units viz. aquitard and aquifer, which consist of clay-silt-sand and sands of different grain sizes respectively. The aquifer zone is further divided into two categories: “small scale aquifer” made dominantly of fine and “main aquifer” comprising of fine-medium to coarse sand. The annual fluctuation of water table in the study area is observed from 4.9 m to 5.6 m. The area is demarcated as three different groundwater bearing zones based on Catastrophe theory using GIS.展开更多
It is controversial whether δVVαμLζ in Metaphysics Book θ has two distinct senses, one of which is strict, called ＂power,＂ and the other is the ＂more useful sense,＂ called ＂potentiality.＂ This paper argues ...It is controversial whether δVVαμLζ in Metaphysics Book θ has two distinct senses, one of which is strict, called ＂power,＂ and the other is the ＂more useful sense,＂ called ＂potentiality.＂ This paper argues that there are indeed two senses of δVVαμLζ in Metaphysics θ, refuting Michael Frede＇s ＂unitarian interpretation.＂ Distinguished from power, potentiality is neither Aristotelian nature, nor possibility, nor capacity for being, but rather a way of being. This paper examines the ontological meanings and the features of potentiality as a way of being. Basically, potentiality has a dual status, that is, it is being, on the one hand, and not-being on the other. Furthermore, it has a teleological direction toward its correlative actuality, which explains how potentiality ontologically depends on actuality and why actuality is substantially prior to potentiality.展开更多
The enhanced mountain-to-plain convective storms in Beijing on 22 May 2021 were simulated using the highresolution Weather Research and Forecasting model,enabling detailed analyses of convective instability characteri...The enhanced mountain-to-plain convective storms in Beijing on 22 May 2021 were simulated using the highresolution Weather Research and Forecasting model,enabling detailed analyses of convective instability characteristics and underlying causes of stability variations.Generalized potential temperature outperformed traditional potential temperature and equivalent potential temperature in capturing instability variations associated with mid-level latent heating and near-surface evaporative cooling.Local instability variance was primarily governed by potential divergence and the advection of potential instability,with these factors exhibiting out-of-phase distributions.Prior to the onset of heavy precipitation,intense downdrafts transported unstable air from higher levels into more stable regions at lower levels,increasing local near-surface instability,which contributed to the formation of heavy precipitation.During the heavy precipitation stage,vertical divergence between slantwise updrafts and downdrafts in the lowmiddle stable layers led to destabilization,supporting sustained convective development within the precipitation area.At the leading edge of the heavy precipitation,instability enhancement was primarily driven by vertical advection,and less stable air in the lower levels was transported upward,enhancing instability at higher levels.展开更多
In this study, the ground potential rise(GPR) phenomenon caused by a lightning current injected into a field-shaped artificial grounding grid, as well as the potential difference between two different nodes at the edg...In this study, the ground potential rise(GPR) phenomenon caused by a lightning current injected into a field-shaped artificial grounding grid, as well as the potential difference between two different nodes at the edge of the grounding grid, was observed and analyzed under artificially triggered lightning conditions. Based on circuit theory and measured current data, a π-equivalent circuit was established to simulate the transient response of the grounding grid.Nineteen return strokes from three artificially triggered lightning events were analyzed. The peak currents of the 19 return strokes range from -6.7 to -25.1 kA, and the mean value was -14.3 kA. The GPR decreased rapidly and formed a subpeak after reaching the initial peak, with the mean value of the initial peak being -148.65 kV and the mean value of the subpeak being -92.87 kV. The GPR induced by the triggered lightning currents exhibited a subpeak phenomenon. Simulation results indicate that the subpeak phenomenon is related to localized corrosion of the vertical grounding electrode. The potential difference at the grounding grid edge exhibited a multi-pulse waveform with alternating polarity, dominated by positive pulses. The peak values of both the positive and negative polarity pulses gradually decreased, with the first positive pulse displaying a significantly higher intensity than that of subsequent pulses.展开更多
Carbonyl compounds play a pivotal role in the formation of secondary pollutants such as O_(3) and SOA,signifi-cantly impacting air quality and human health.This study extended the observation period compared to previo...Carbonyl compounds play a pivotal role in the formation of secondary pollutants such as O_(3) and SOA,signifi-cantly impacting air quality and human health.This study extended the observation period compared to previous research,providing a long-term perspective on carbonyl compound variations and their environmental implica-tions.Atmospheric observations were conducted at Beijing(BJ)and Xianghe(XH)during the summer and winter months of 2018,2019,and 2023 to study the sources and impacts of carbonyl compounds in typical urban areas and peri‑urban areas.Notably,concentrations in the summer of 2023 increased compared to 2018 and 2019.The predominant carbonyl compounds—formaldehyde,acetaldehyde,and acetone—accounted for over 60%of the total.The mean values of OFP in BJ ranged from 18.55 to 58.61μg/m3,lower than those in XH(29.82 to 65.48μg/m3),with formaldehyde and acetaldehyde contributing over 80%of the total.SOAP exhibited a similar pattern,with values in XH(69.21 to 508.55μg/m3)significantly exceeding those in BJ(34.47 to 159.78μg/m3).The PMF model highlighted vehicle exhaust,secondary pollution,and biomass combustion as major sources of carbonyl compounds,emphasizing differences in source contributions between the two regions.This study’s com-parative analysis over different years and locations provides new insights into the dynamic changes in carbonyl compounds and their environmental importance.These results not only reinforce the importance of carbonyl compounds regulation but also offer a valuable reference for evaluating and refining emission control strategies during this period.展开更多
Paying an additional RMB 2 could have your next milk tea delivered by drone to your balcony in just five minutes.This small fee represents the vast potential of the trillion-yuan lowaltitude economy.
Objectives Glioblastoma multiforme(GBM)is highly resistant to apoptosis.This study investigates the role of Selenoprotein M(SELENOM),a redox-regulating protein,in the response of human glioblastoma A-172 cells to stau...Objectives Glioblastoma multiforme(GBM)is highly resistant to apoptosis.This study investigates the role of Selenoprotein M(SELENOM),a redox-regulating protein,in the response of human glioblastoma A-172 cells to staurosporine(STS)and hyperthermia.Methods A stable SELENOM-knockdown(SELENOM-KD)cell line was created.We measured reactive oxygen species(ROS),mitochondrial membrane potential(ΔΨm),cell death,and apoptotic gene expression.Results SELENOM-KD increased basal ROS levels and induced mitochondrial dysfunction.It sensitized cells to STS-induced apoptosis,enhancing the upregulation of pro-apoptotic genes.Conversely,under hyperthermia(42°C),SELENOM-KD cells exhibited significant thermoresistance,with 52%survival vs.99%death in controls,associated with suppressed pro-apoptotic signaling.Conclusions SELENOM is a critical redox and mitochondrial regulator in GBM.Its loss produces a context-dependent effect on cell fate:sensitizing to chemical apoptosis while conferring resistance to hyperthermia.SELENOM expression is a promising predictive biomarker for stratifying GBM patients for hyperthermia-based therapies.展开更多
The transport behavior of pollutants under dynamic groundwater conditions has attracted significant attention recently.However,there is limited research on the simultaneous effects of groundwater table fluctuations on...The transport behavior of pollutants under dynamic groundwater conditions has attracted significant attention recently.However,there is limited research on the simultaneous effects of groundwater table fluctuations on the transport of co-existing pollutants,especially combined dense and light non-aqueous phase liquids(DNAPLs and LNAPLs).In this study,column experiments investigated toluene and dichloromethane transport in a controlled water table system with varying fluctuation conditions.Results showed that both dichloromethane and toluene accumulated near the groundwater table under static water table conditions,but the concentration of dichloromethane declined more rapidly than toluene due to differences in their physicochemical properties,such as solubility,density,and hydrophobicity.Groundwater fluctuations facilitated pollutants transportation towards deeper layers,potentially resulting in unforeseen increases in pollutant volatilization and downward fluxes.The interactions between dichloromethane and toluene,including competitive adsorption,enhanced dissolution,and altered kinematic viscosities,resulted in the reduced transport potential of dichloromethane while enhancing that of toluene.Furthermore,compared to dichloromethane,the initial upward fluctuation of the water table had a more pronounced impact on toluene due to its lower solubility and volatility.The downward transport risk index assessment indicated that among various factors considered,groundwater fluctuation amplitude exerted the most significant influence on pollutant migration risk.These new findings will provide important insights into understanding and assessment of the potential transport risk associated with combined LNAPLs and DNAPLs in the natural environment.展开更多
Conjugated microporous polymers(CMPs)are a unique class of organic porous materials characterized byπ-conjugated structures and permanent micropores,distinguishing them from non-porous polymers and conventionalπ-con...Conjugated microporous polymers(CMPs)are a unique class of organic porous materials characterized byπ-conjugated structures and permanent micropores,distinguishing them from non-porous polymers and conventionalπ-conjugated polymers.CMPs offer extensive versatility in synthetic approaches,enabling the synthesis of cross-linked and mesoporous structures.Advances in chemical processes,structural design,and synthesis methodologies have been developed,resulting in a diverse range of CMPs with unique configurations and properties,contributing to the fast expansion of the field.CMPs are particularly notable for their ability to enable the competitive utilization ofπ-conjugated structures within mesoporous configurations,making them valuable for investigations across various domains.They have shown considerable promise in addressing fuel and environmental challenges,demonstrated by their exceptional performance in applications such as vapor adsorption,heterogeneous catalysis,light emission,light harvesting,and energy generation.This review examines the chemical engineering principles underlying CMPs,including synthesis approaches,systemic research advancements,multifunctional investigations boundaries,potential applications,and progress in synthesis,dimensionality,and morphology studies.Specifically,it offers a comparative analysis of CMPs and linear polymeric materials,aiding in the development of functional polymers.Furthermore,this review explores the primary fundamental limitations of CMPs in fuel-related domains and discusses alternative strategies,including novel synthesis methods incorporating interactions and morphologies,to address these challenges.Ultimately,this assessment aims to provide a valuable and inspiring resource for professionals in the field of fuel management,guiding future research and development efforts.展开更多
BACKGROUND:Although the Confusion Assessment Methods for the Intensive Care Unit(CAMICU) is a recommended tool for diagnosing sepsis-associated encephalopathy(SAE),it has several limitations.Mismatch-negativity(MMN) a...BACKGROUND:Although the Confusion Assessment Methods for the Intensive Care Unit(CAMICU) is a recommended tool for diagnosing sepsis-associated encephalopathy(SAE),it has several limitations.Mismatch-negativity(MMN) and P3a are components of event-related potentials(ERPs) used with electroencephalography(EEG) and are associated with cerebral function changes in critically ill patients.This study aimed to provide a quantitative,non-invasive method to guide SAE diagnosis in nonsedated patients.METHODS:From January 2022 to March 2023,sepsis patients without sedation were enrolled and assessed via the CAM-ICU,Glasgow Coma Scale(GCS),and ERP under standard procedures.Both MMN and P3a data were collected.The diagnostic value of MMN and P3a was assessed with processed ERP data.RESULTS:Thirty-six patients were included in this study,comprising 19 patients with SAE and 17 patients without SAE(NSAE).MMN and P3a amplitudes decreased,and only FzMMN amplitude significantly decreased in SAE patients(2.03 [1.08,2.93] mV vs.3.21 [1.92,4.34] mV,P=0.040).After median dichotomization,low F3P3a and FzP3a amplitudes were associated with higher CAM-ICU positivity rates and APACHE II scores.Both amplitude in F3P3a(AUC=0.710,95%CI:0.527–0.893,P=0.034) and FzP3a(AUC=0.700,95%CI:0.519–0.881,P=0.041) exhibited moderate diagnostic efficacy for SAE,while FzMMN amplitude lacks effective diagnostic value.CONCLUSION:In this pilot study,ERP components F3P3a and FzP3a amplitudes demonstrated moderate diagnostic value for SAE.These exploratory findings require confirmation in larger and powered cohorts.展开更多
Nitrogen(N)and phosphorus(P)are essential nutrients and can significantly impact primary productivity of the ecosystem causing water environmental problems.However,their cycling mechanisms are not well understood in a...Nitrogen(N)and phosphorus(P)are essential nutrients and can significantly impact primary productivity of the ecosystem causing water environmental problems.However,their cycling mechanisms are not well understood in alpine mountains with climate change.Hence,94 samples of river water were collected from 2018 to 2020 in the headwaters of the Shule River Basin to assess the nutrients spatiotemporal distribution and combined ap-proach of water quality index to assess water quality and potential sources.The findings depict that high nutrient concentrations were found to coincide with snowmelt and glacial meltwater and rainfall recharge periods,while total flux peaked from June to September due to increased runoff.Notably,total nitrogen(TN)concentrations were significantly higher near the town,primarily attributed to the replenishment of nitrate(NO_(3)^(‒)-N)from live-stock manure.The high total P(TP)was near the glacier,which was attributed to the transportation of glacial sediments into the river,and pH was another critical factor.N was the primary nutrient limiting factor for the growth of phytoplankton in river water.Although the migration and transport of nutrients have altered with climate change,river water quality is good in alpine mountains based on an overall evaluation.These findings contribute to enriching nutrient datasets and highlight the importance of water resource management and water quality assessment in sensitive and fragile alpine mountains.展开更多
文摘China has launched her first ocean color satellite HY-1A on May 15, 2002 since American ocean color satellite SeaSTAR was on the orbit in 1997. First, the properties and characteristics of HY-1A are briefly introduced; second, the quality and availability are evaluated by means of the complex signal noise ratio ( CSNR) which is simulated theoretically; third, the received HY-1A data are compared with SeaSTAR data to understand the accuracy of radiance measurement by the HY-1A; finally, the remote sensing products of ocean color and temperature are mapped to study the application potentiality of HY-1A. The results show that the HY-1A has its latent capability for the application of marine environment detection, the management and protection of marine resources, and the national rights and interests. Meanwhile some suggestions are proposed to modify the next ocean satellite.
基金the financial support of the National Natural Science Foundation of China(U2268208)Science and Technology Program of China National Railway Group Co.,Ltd.(N2022×037).
文摘This study addresses the comparative carbon emissions of different transportation modes within a unified evaluation framework,focusing on their carbon footprints from inception to disposal.Specifically,the entire life cycle carbon emissions of High-Speed Rail(HSR),battery electric vehicles,conventional internal combustion engine vehicles,battery electric buses,and conventional internal combustion engine buses are analyzed.The life cycle is segmented into vehicle manufacturing,fuel or electricity production,operational,and dismantlingrecycling stages.This analysis is applied to the Beijing-Tianjin intercity transportation system to explore emission reduction strategies.Results indicate that HSR demonstrates significant carbon emission reduction,with an intensity of only 24%-32% compared to private vehicles and 47%-89% compared to buses.Notably,HSR travel for Beijing-Tianjin intercity emits only 24% of private vehicle emissions,demonstrating the emission reduction benefits of transportation structure optimization.Additionally,predictive modeling reveals the potential for carbon emission reduction through energy structure optimization,providing a guideline for the development of effective transportation management systems.
文摘The Jurassic in the northern Qaidam basin is an independent petroleum system.To find high－ quality source rock is the key problem in exploration.The result of plate tectonics research shows that the Jurassic basin had been formed in an extensional tectonic stress field after the Indo－ China movement along northwest and northeast directions.It belongs to a kind of compound fault subsidence.The area,where the different direction subsidences overlapped,is the oil－ generating center,and also is the favourable exploration target.
基金supported by the Govt,of Kerala(Order Nos. Ac.E.l.B.1.27808/04 Dt.28.04.2005)
文摘Objective:Natural products of plant origin are potential source of novel antimicrobial and antioxidative agents.Thottea siliquosa(Lam.)Ding Hou.(T.siliquosa).A medicinal herb used by local tribals for treating various ailments.The present study aims at the phytochemical screening,GC-MS analysis,in vitro antibacterial activity and antioxidant potentiality of root and leaf extracts of T.siliquosa.Methods:Hot continuous Soxhlct extraction,GC-MS analysis,antibacterial analysis by disc diffusion,microdilution assay and antioxidant potentialities by hydroxyl radical and nitric oxide radical scavenging.The data was statistically analyzed.Results:Phytochemical screening of the ethyl acetate and methanolic extract of leaf and root revealed the presence of phenols,alkaloids,tannins and saponin.The extract revealed a pool of phytochemicals by comparison with authentic standards from spectral library.Both the extracts has shown their broad spectrum of inhibition against the selected bacteria Staphylococcus aureus,Escherichia coli,Pseudomonas aeruginosa and Klebsiella pneumonia compared with standard antibiotic drug streptomycin.The extracts showed antioxidant activity by scavenging of free radicals such as hydroxyl and nitric oxide.The IC_(50)values of the ethyl acetate extracts leaf and root and standard in this assay were I67.5±0.67,99.4±1.2,192±2.5μg/mL respectively.Similarly those methanolic extracts of leaf and root were 269.5±0.89 and 289.1±2.66μg/mL respectively.Similarly,ethyl acetate and methanolic extracts also caused a moderate dose-dependent inhibition of nitric oxide with an IC_(50)range 65.5±1.55 to 148±3.09μg/mL.The inhibitory activities were found to be dose dependent.Conclusion:The present study provides evidence that ethyl acetate and methanol extract of leaf and root of T.siliquosa are potential source of natural antioxidants and bactericidal nature.It is essential that research should continue to isolate and purify the bio active components of this natural plant and use in drug discovery and development.
基金the Foundation of National sib Five-year-plan of China
文摘A series of comparative studies was carried out on the genetic effects of 25 alien cytoplasms of wheat on the growth potential, heading stage, fertility, resistance against diseases, important agronomic traits and its heterosis of 125 nuclei-cytoplasmic hybrids of wheat. The results indicated that there were clearly effects of alien cytoplasms on some characteristics, but the nucleus still exerted main effect on other characteristics. The effect of interactions between nucleus and cytoplasm was comparative obvious in some combination. Consequently, when we utilize the effects of alien cytoplasms, we should pay full attention to the facts such as the characteristic to be improved, the effects of cytoplasm, nucleus, the nucleus-cytoplasm interactions on that characteristics. From the preliminary studies, we believed that the cytoplasmic types of M0, S1, Sv, D2, D and B, and the nucleo-cytoplasmic hybrids of (Ae. sharonensis)-B174, (Ae. squarrosa)-352-35 (Ae. cylindrica)-352-35, (Ae. cylindria)-E EN-1, (Ae. cylindrica)-NPFP, and (Ae. speltoides)-352-35 would have some utilization potentiality in cultivar improvement.
文摘The research was elaborated in Kafr El-Dawar area (Egypt northern region) to study the availability of the soil plant nutrients. The research introduced three parameters to comprehensively and carefully describe the availability of the soil plant nutrients: potentiality, gradient and anisotropy. Potentiality defines the categories of soil ability to supply plant nutrients;meanwhile gradient expresses the increasing rate of the availability of the soil plant nutrients. The gradient anisotropy refers to the directions or orientation of the increasing rate of the availability of the soil plant nutrients. The introduced parameters enabled to spatially study the availability of the soil plant nutrients. Analytical data, of soil available phosphorus (P), indicated that P ranged from 0.2 ppm to 11.4 ppm to locate all studied soil samples into the low class of the soil nutritional P ability. This was not the case of available potassium (K), where the soil samples were distributed into three available K soil categories: medium, high, and very high. GIS map of soil P nutritional potentiality for plant (potato), displayed the soil studied area in one category, as low P soil nutritional potentiality to coincide with the analytical data classification. Contrary, the K map classified the soil studied area into three categories of soil K nutritional potentiality: medium, high and excessive. This obviously referred that the individual determination of soil K nutritional potentiality is misleading for interpretation of soil tests because it does care of the spatial distribution of soil available K. Nearly, all soil samples had high available micronutrients that they were located in the high category in both classification of analytical data and GIS maps. GIS gradient maps of the soil available plant nutrients referred that the soil plant nutrients, exception of K, had two gradients: non increasing-slight increasing and build up. Gradient of soil available potassium was classified into four classes: non increasing-slight increasing, build up, moderately increasing and hike. Regardless potassium case, the non increasing-slight increasing gradient class dominated the others. GIS maps of anisotropy soil availability of macronutrients (P and K) generally showed that their gradients mainly increased in two directions: north and south. The incasing directions of soil availability of micronutrients coincided with that of the macronutrients.
基金supported by the Graduate Student Innovation Fund of Hebei Province (No.197)
文摘Based on the groundwater resources evaluation, the groundwater exploitation potentiality evaluation is aiming at providing references for management, planning and development of groundwater. Traditional evaluation methods mainly adopted individual indicator as a method which cannot fully reflect the affecting factors of the groundwater exploitation potential in a scientific way. The idea that the spatial distribution and dynamic change of groundwater is not only affected by socio-economic development and exploitation technology but also influenced by its regulation is coincided with the niche theory. This paper has preliminarily applied the niche theory to groundwater exploitation potential analysis, and proposed the concept of groundwater niche as well as its related definition, connotation and calculation formula. Meanwhile, by taking the Hebei Plain as an example, the article has made an evaluation of groundwater exploitation potentiality and a contrast with the results of the traditional evaluation methods on the construction of groundwater niche index system, and then verified the feasibility and rationality of this index system. It turns out that, it is truly comprehensive, scientific and rational to make groundwater niche calculation and exploitation potential analysis by using the evaluation index system. Niche theory has provided a new and fundamental attempt for the analysis and competition strategy for the groundwater exploitation potentiality evaluation.
文摘Objective: To assess the developing potentiality of mouse morula produced in vitro or in the after vitrification and to evaluate the effect of one-step and two-step vitrification methods. Method: Mouse morula produced in for and in the were vitrified in the solution containing ethylene glycol, Ficoll and sucrose (EFS solution) with one-step and two-step methods. The developing potential and status of the pellucid zona in vitified mouse morula were assessed. Results: The percentages of morula developed into blastocyst stage were 81. 8% and 82.4%, 97. 3% and 98.4%, respectively, after one-step and two-step exposure of in vitro morula or in vivo morula to EFS solution alone, which did not show significant difference compared to their controls (P > 0. 05). The percentage of in vitro morula developed into blastocyst vitrified by onestep method was significantly lower than that by two-step method and coned (P < 0.05, 70.6% vs 81 .3%; 70.6% vs 83 .6%, respectively). However, there was no significant difference between blastocyst rates of in vivo morula vitrified by one-step and two-step methods (P>0.05, 93. 1% us 95.7%). No rupture of pellucid zona was observed in all thawed morula after one-step and two-step vitrification, irrespective of in vitro morula or in vivo morula. Conclusion: Morula produced in vitro and in vivo after vitrification may maintain high survival rate and developing potential. Two-step vitrification method with EFS solution is suitable for in vitro morula, which can improve the developing potential of in vitro morula. Onestep and two-step vitrification method have no detrimennd effect on the developing potential of in vivo morula.
基金the International Center for Research in Agroforestry(ICRAF)New Delhi Regional Centre for its motivation and support in conducting this study.
文摘Scaling-up agroforestry area in various forms is a scientific path towards achieving various sustainable development goals(SDGs),especially improving livelihood,reducing poverty,conserving environment and biodiversity,and transforming climate change.In this study,the effort was made to investigate the land potentiality for agroforestry at the district level in Jharkhand State,India by applying geographic information system(GIS)modeling technology using climate(temperature and precipitation),topography(slope and elevation),ecology(percent tree cover and normalized difference vegetation index(NDVI)),and social economics(poverty rate and tribal dominance)factors.The results revealed that six districts of Jharkhand State had agroforestry potential greater than 60.00%.The highest agroforestry suitability was found in Simdega District(78.20%),followed by Pakur(76.25%),West Singhbhum(72.70%),Dumka(68.84%),Sahibganj(64.63%),and Godda(63.43%)districts.Additionally,we identified 513 out of 32,620 villages of Jharkhand State potentially suitable(agroforestry suitability≥80.00%)for agroforestry with the objective of life improvement among marginalized society.Under the outside forest area,8.58%of the total geographical land of Jharkhand State was wasteland,much of which was found suitable for agroforestry practices.The agroforestry setups in those wastelands can absorb 637 t carbon annually in long run and can provide direct economic benefits to the locals besides additional income for carbon emission reduction.This study concluded that Jharkhand State has plenty of high potential land for agroforestry,and adoption of agroforestry at the village level must be given high priority.This study could guide the nodal authorities to prepare appropriate strategies for scaling the tree cover in agroforestry systems in village-level landscape planning which needs policy attention and investment for achieving 9 out of the 17 SDGs.
文摘To identify the potential groundwater bearing zones for future groundwater resources development of the study area, an investigation has been made using lithology, groundwater monitoring and elevation data. The stratigraphic cross-sections of the area reveal six distinct hydrostratigraphic features viz. clay-silt-sand, fine sand, fine to medium sand, medium sand, medium to coarse sand and coarse sand. On the basis of lithological information, the groundwater bearing zone of the area has been divided into two main hydrostratigraphic units viz. aquitard and aquifer, which consist of clay-silt-sand and sands of different grain sizes respectively. The aquifer zone is further divided into two categories: “small scale aquifer” made dominantly of fine and “main aquifer” comprising of fine-medium to coarse sand. The annual fluctuation of water table in the study area is observed from 4.9 m to 5.6 m. The area is demarcated as three different groundwater bearing zones based on Catastrophe theory using GIS.
文摘It is controversial whether δVVαμLζ in Metaphysics Book θ has two distinct senses, one of which is strict, called ＂power,＂ and the other is the ＂more useful sense,＂ called ＂potentiality.＂ This paper argues that there are indeed two senses of δVVαμLζ in Metaphysics θ, refuting Michael Frede＇s ＂unitarian interpretation.＂ Distinguished from power, potentiality is neither Aristotelian nature, nor possibility, nor capacity for being, but rather a way of being. This paper examines the ontological meanings and the features of potentiality as a way of being. Basically, potentiality has a dual status, that is, it is being, on the one hand, and not-being on the other. Furthermore, it has a teleological direction toward its correlative actuality, which explains how potentiality ontologically depends on actuality and why actuality is substantially prior to potentiality.
基金funded by the Beijing Municipal Science and Technology Commission [grant number Z221100005222012]the Department of Science and Technology of Hebei Province [grant number 22375404D]+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences [grant number XDB0760303]the National Natural Science Foundation of China [grant numbers U2233218 and 42275010]the Open Foundation of the Key Open Laboratory of Urban Meteorology,China Meteorological Administration [grant number LUM-2023-06]。
文摘The enhanced mountain-to-plain convective storms in Beijing on 22 May 2021 were simulated using the highresolution Weather Research and Forecasting model,enabling detailed analyses of convective instability characteristics and underlying causes of stability variations.Generalized potential temperature outperformed traditional potential temperature and equivalent potential temperature in capturing instability variations associated with mid-level latent heating and near-surface evaporative cooling.Local instability variance was primarily governed by potential divergence and the advection of potential instability,with these factors exhibiting out-of-phase distributions.Prior to the onset of heavy precipitation,intense downdrafts transported unstable air from higher levels into more stable regions at lower levels,increasing local near-surface instability,which contributed to the formation of heavy precipitation.During the heavy precipitation stage,vertical divergence between slantwise updrafts and downdrafts in the lowmiddle stable layers led to destabilization,supporting sustained convective development within the precipitation area.At the leading edge of the heavy precipitation,instability enhancement was primarily driven by vertical advection,and less stable air in the lower levels was transported upward,enhancing instability at higher levels.
基金National Natural Science Foundation of China(42575091)Marine Meteorological Science and Data Center Program (2024B1212070014)。
文摘In this study, the ground potential rise(GPR) phenomenon caused by a lightning current injected into a field-shaped artificial grounding grid, as well as the potential difference between two different nodes at the edge of the grounding grid, was observed and analyzed under artificially triggered lightning conditions. Based on circuit theory and measured current data, a π-equivalent circuit was established to simulate the transient response of the grounding grid.Nineteen return strokes from three artificially triggered lightning events were analyzed. The peak currents of the 19 return strokes range from -6.7 to -25.1 kA, and the mean value was -14.3 kA. The GPR decreased rapidly and formed a subpeak after reaching the initial peak, with the mean value of the initial peak being -148.65 kV and the mean value of the subpeak being -92.87 kV. The GPR induced by the triggered lightning currents exhibited a subpeak phenomenon. Simulation results indicate that the subpeak phenomenon is related to localized corrosion of the vertical grounding electrode. The potential difference at the grounding grid edge exhibited a multi-pulse waveform with alternating polarity, dominated by positive pulses. The peak values of both the positive and negative polarity pulses gradually decreased, with the first positive pulse displaying a significantly higher intensity than that of subsequent pulses.
基金supported by the National Natural Science Foundation of China(Nos.41905108 and 42130704).
文摘Carbonyl compounds play a pivotal role in the formation of secondary pollutants such as O_(3) and SOA,signifi-cantly impacting air quality and human health.This study extended the observation period compared to previous research,providing a long-term perspective on carbonyl compound variations and their environmental implica-tions.Atmospheric observations were conducted at Beijing(BJ)and Xianghe(XH)during the summer and winter months of 2018,2019,and 2023 to study the sources and impacts of carbonyl compounds in typical urban areas and peri‑urban areas.Notably,concentrations in the summer of 2023 increased compared to 2018 and 2019.The predominant carbonyl compounds—formaldehyde,acetaldehyde,and acetone—accounted for over 60%of the total.The mean values of OFP in BJ ranged from 18.55 to 58.61μg/m3,lower than those in XH(29.82 to 65.48μg/m3),with formaldehyde and acetaldehyde contributing over 80%of the total.SOAP exhibited a similar pattern,with values in XH(69.21 to 508.55μg/m3)significantly exceeding those in BJ(34.47 to 159.78μg/m3).The PMF model highlighted vehicle exhaust,secondary pollution,and biomass combustion as major sources of carbonyl compounds,emphasizing differences in source contributions between the two regions.This study’s com-parative analysis over different years and locations provides new insights into the dynamic changes in carbonyl compounds and their environmental importance.These results not only reinforce the importance of carbonyl compounds regulation but also offer a valuable reference for evaluating and refining emission control strategies during this period.
文摘Paying an additional RMB 2 could have your next milk tea delivered by drone to your balcony in just five minutes.This small fee represents the vast potential of the trillion-yuan lowaltitude economy.
基金the framework of the State assignment No.075-00607-25-00.
文摘Objectives Glioblastoma multiforme(GBM)is highly resistant to apoptosis.This study investigates the role of Selenoprotein M(SELENOM),a redox-regulating protein,in the response of human glioblastoma A-172 cells to staurosporine(STS)and hyperthermia.Methods A stable SELENOM-knockdown(SELENOM-KD)cell line was created.We measured reactive oxygen species(ROS),mitochondrial membrane potential(ΔΨm),cell death,and apoptotic gene expression.Results SELENOM-KD increased basal ROS levels and induced mitochondrial dysfunction.It sensitized cells to STS-induced apoptosis,enhancing the upregulation of pro-apoptotic genes.Conversely,under hyperthermia(42°C),SELENOM-KD cells exhibited significant thermoresistance,with 52%survival vs.99%death in controls,associated with suppressed pro-apoptotic signaling.Conclusions SELENOM is a critical redox and mitochondrial regulator in GBM.Its loss produces a context-dependent effect on cell fate:sensitizing to chemical apoptosis while conferring resistance to hyperthermia.SELENOM expression is a promising predictive biomarker for stratifying GBM patients for hyperthermia-based therapies.
基金supported by the National Key Research and Development Project of China(Nos.2024YFC3713802 and 2023YFC3709700)the Strategic Priority Research Program of the Chinese Academy of Sciences,China(No.XDA23030202)the Science and Technology Program for Foreign Cooperation in Fujian Province of China(No.2022I0040).
文摘The transport behavior of pollutants under dynamic groundwater conditions has attracted significant attention recently.However,there is limited research on the simultaneous effects of groundwater table fluctuations on the transport of co-existing pollutants,especially combined dense and light non-aqueous phase liquids(DNAPLs and LNAPLs).In this study,column experiments investigated toluene and dichloromethane transport in a controlled water table system with varying fluctuation conditions.Results showed that both dichloromethane and toluene accumulated near the groundwater table under static water table conditions,but the concentration of dichloromethane declined more rapidly than toluene due to differences in their physicochemical properties,such as solubility,density,and hydrophobicity.Groundwater fluctuations facilitated pollutants transportation towards deeper layers,potentially resulting in unforeseen increases in pollutant volatilization and downward fluxes.The interactions between dichloromethane and toluene,including competitive adsorption,enhanced dissolution,and altered kinematic viscosities,resulted in the reduced transport potential of dichloromethane while enhancing that of toluene.Furthermore,compared to dichloromethane,the initial upward fluctuation of the water table had a more pronounced impact on toluene due to its lower solubility and volatility.The downward transport risk index assessment indicated that among various factors considered,groundwater fluctuation amplitude exerted the most significant influence on pollutant migration risk.These new findings will provide important insights into understanding and assessment of the potential transport risk associated with combined LNAPLs and DNAPLs in the natural environment.
基金supported by the King Khalid University,Abha,Saudi Arabiathe Deanship of Scientific Research at King Khalid University for funding this work through Large Groups Project under grant number(R.G.P.2/335/46)the Guangdong Office of Research Projects at the Provincial University(No.2024KCXTD064)。
文摘Conjugated microporous polymers(CMPs)are a unique class of organic porous materials characterized byπ-conjugated structures and permanent micropores,distinguishing them from non-porous polymers and conventionalπ-conjugated polymers.CMPs offer extensive versatility in synthetic approaches,enabling the synthesis of cross-linked and mesoporous structures.Advances in chemical processes,structural design,and synthesis methodologies have been developed,resulting in a diverse range of CMPs with unique configurations and properties,contributing to the fast expansion of the field.CMPs are particularly notable for their ability to enable the competitive utilization ofπ-conjugated structures within mesoporous configurations,making them valuable for investigations across various domains.They have shown considerable promise in addressing fuel and environmental challenges,demonstrated by their exceptional performance in applications such as vapor adsorption,heterogeneous catalysis,light emission,light harvesting,and energy generation.This review examines the chemical engineering principles underlying CMPs,including synthesis approaches,systemic research advancements,multifunctional investigations boundaries,potential applications,and progress in synthesis,dimensionality,and morphology studies.Specifically,it offers a comparative analysis of CMPs and linear polymeric materials,aiding in the development of functional polymers.Furthermore,this review explores the primary fundamental limitations of CMPs in fuel-related domains and discusses alternative strategies,including novel synthesis methods incorporating interactions and morphologies,to address these challenges.Ultimately,this assessment aims to provide a valuable and inspiring resource for professionals in the field of fuel management,guiding future research and development efforts.
基金supported by the CAMS Innovation Fund for Medical Sciences (CIFMS)(No.2021-1-I2M-020)National High Level Hospital Clinical Research Funding (No.2022-PUMCH-B-109)National Natural Science Foundation of China (82402543)。
文摘BACKGROUND:Although the Confusion Assessment Methods for the Intensive Care Unit(CAMICU) is a recommended tool for diagnosing sepsis-associated encephalopathy(SAE),it has several limitations.Mismatch-negativity(MMN) and P3a are components of event-related potentials(ERPs) used with electroencephalography(EEG) and are associated with cerebral function changes in critically ill patients.This study aimed to provide a quantitative,non-invasive method to guide SAE diagnosis in nonsedated patients.METHODS:From January 2022 to March 2023,sepsis patients without sedation were enrolled and assessed via the CAM-ICU,Glasgow Coma Scale(GCS),and ERP under standard procedures.Both MMN and P3a data were collected.The diagnostic value of MMN and P3a was assessed with processed ERP data.RESULTS:Thirty-six patients were included in this study,comprising 19 patients with SAE and 17 patients without SAE(NSAE).MMN and P3a amplitudes decreased,and only FzMMN amplitude significantly decreased in SAE patients(2.03 [1.08,2.93] mV vs.3.21 [1.92,4.34] mV,P=0.040).After median dichotomization,low F3P3a and FzP3a amplitudes were associated with higher CAM-ICU positivity rates and APACHE II scores.Both amplitude in F3P3a(AUC=0.710,95%CI:0.527–0.893,P=0.034) and FzP3a(AUC=0.700,95%CI:0.519–0.881,P=0.041) exhibited moderate diagnostic efficacy for SAE,while FzMMN amplitude lacks effective diagnostic value.CONCLUSION:In this pilot study,ERP components F3P3a and FzP3a amplitudes demonstrated moderate diagnostic value for SAE.These exploratory findings require confirmation in larger and powered cohorts.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(No.2019QZKK0208)the National Natural Science Foundation of China(Nos.42171148 and 42330512)the Key R&D Project from the Science and Technology Department of Tibet(No.XZ202501ZY0030).
文摘Nitrogen(N)and phosphorus(P)are essential nutrients and can significantly impact primary productivity of the ecosystem causing water environmental problems.However,their cycling mechanisms are not well understood in alpine mountains with climate change.Hence,94 samples of river water were collected from 2018 to 2020 in the headwaters of the Shule River Basin to assess the nutrients spatiotemporal distribution and combined ap-proach of water quality index to assess water quality and potential sources.The findings depict that high nutrient concentrations were found to coincide with snowmelt and glacial meltwater and rainfall recharge periods,while total flux peaked from June to September due to increased runoff.Notably,total nitrogen(TN)concentrations were significantly higher near the town,primarily attributed to the replenishment of nitrate(NO_(3)^(‒)-N)from live-stock manure.The high total P(TP)was near the glacier,which was attributed to the transportation of glacial sediments into the river,and pH was another critical factor.N was the primary nutrient limiting factor for the growth of phytoplankton in river water.Although the migration and transport of nutrients have altered with climate change,river water quality is good in alpine mountains based on an overall evaluation.These findings contribute to enriching nutrient datasets and highlight the importance of water resource management and water quality assessment in sensitive and fragile alpine mountains.
