期刊文献+
共找到20,718篇文章
< 1 2 250 >
每页显示 20 50 100
Impact of coking plant to heavy metal characteristics in groundwater of surrounding areas:Spatial distribution,source apportionment and risk assessments 被引量:1
1
作者 Congqing Wang Wanjun Wang +5 位作者 ChaoWang Shixing Ren Yingjun Wu Meicheng Wen Guiying Li Taicheng An 《Journal of Environmental Sciences》 2025年第3期688-698,共11页
Coking industry is a potential source of heavy metals(HMs)pollution.However,its impacts to the groundwater of surrounding residential areas have not been well understood.This study investigated the pollution character... Coking industry is a potential source of heavy metals(HMs)pollution.However,its impacts to the groundwater of surrounding residential areas have not been well understood.This study investigated the pollution characteristics and health risks of HMs in groundwater nearby a typical coking plant.Nine HMs including Fe,Zn,Mo,As,Cu,Ni,Cr,Pb and Cd were analyzed.The average concentration of total HMswas higher in the nearby area(244.27μg/L)than that of remote area away the coking plant(89.15μg/L).The spatial distribution of pollution indices including heavy metal pollution index(HPI),Nemerow index(NI)and contamination degree(CD),all demonstrated higher values at the nearby residential areas,suggesting coking activity could significantly impact the HMs distribution characteristics.Four sources of HMs were identified by Positive Matrix Factorization(PMF)model,which indicated coal washing and coking emission were the dominant sources,accounted for 40.4%,and 31.0%,respectively.Oral ingestionwas found to be the dominant exposure pathway with higher exposure dose to children than adults.Hazard quotient(HQ)values were below 1.0,suggesting negligible non-carcinogenic health risks,while potential carcinogenic risks were from Pb and Ni with cancer risk(CR)values>10−6.Monte Carlo simulation matched well with the calculated results with HMs concentrations to be the most sensitive parameters.This study provides insights into understanding how the industrial coking activities can impact the HMs pollution characteristics in groundwater,thus facilitating the implement of HMs regulation in coking industries. 展开更多
关键词 Coking industry Heavy metal GROUNDWATER spatial distribution Source apportionment Monte Carlo simulation
原文传递
Spatial distribution,influencing factors,and environmental risk assessments of mercury in surface soils over Xinjiang,northwestern China
2
作者 Zhengzheng Yang Shiwei Sun +5 位作者 Xiwen Miao Shichang Kang Pengfei Chen Dipesh Rupakheti Zhaofu Hu Junming Guo 《Journal of Environmental Sciences》 2025年第12期555-568,共14页
Since scarce knowledge of soil mercury(Hg)concentrations and risks in the vulnerable Xinjiang,topsoils(0-15 cm)from its typical landscapes were extensively sampled.Topsoil total mercury(THg)concentrations varied broad... Since scarce knowledge of soil mercury(Hg)concentrations and risks in the vulnerable Xinjiang,topsoils(0-15 cm)from its typical landscapes were extensively sampled.Topsoil total mercury(THg)concentrations varied broadly between 0.9 and 35.3 ng/g,of which16.8%exceeded the background value of soil Hg for Xinjiang.Topsoil THg concentrations across various landscapes exhibited a declining order:farmland(11.7±6.0 ng/g)>grassland(10.5±8.5 ng/g)>woodland(10.2±8.2 ng/g)>desert(7.0±5.8 ng/g).The average topsoil THg concentration was higher in northwestern Xinjiang(11.3±7.2 ng/g)than that in southeastern Xinjiang(6.3±6.1 ng/g).Relatively high topsoil THg concentrations were observed near the cities with intensive human activities,followed by a gradual decline to the surroundings.The concentrations of topsoil THg were strongly correlated with the contents of total organic carbon(TOC),clay,silty,and sandy,and the distance from each sampling site to its nearest city,suggesting that the variation of topsoil Hg was significantly influenced by TOC content,soil granularity,and anthropogenic Hg emissions.Silty and TOC were the principal affecting factors,explaining 48.7%and 7.9%of the THg variation,respectively.The contamination and potential ecological risk evaluations revealed that topsoils in regions with dense populations were polluted with Hg and contained higher potential ecological risks.The health risk evaluations indicated that exposure risks of topsoil Hg were higher for children than those for adults.Fortunately,topsoil Hg posed acceptable risks to human health. 展开更多
关键词 MERCURY TOPSOIL LANDSCAPE spatial distribution Risk assessment XINJIANG
原文传递
Spatial distribution of oxygen vacancy on ceria catalysts for chemoselective synthesis of lignin-derived cyclohexanol
3
作者 Yuangao Wang Yu Luo +4 位作者 Chenwei Liu Feng Du Wenjuan Yan Xin Jin Chaohe Yang 《Journal of Energy Chemistry》 2025年第7期565-576,共12页
The synergy of metal/oxygen vacancy(O_(v))pairs is critical in catalyzing activation of C-H,C=C,and C-O bonds.However,gaining fundamental understanding on spatial distance of metallic and O_(v)sites on catalyst surfac... The synergy of metal/oxygen vacancy(O_(v))pairs is critical in catalyzing activation of C-H,C=C,and C-O bonds.However,gaining fundamental understanding on spatial distance of metallic and O_(v)sites on catalyst surface would lead to unexpected chemoselectivity toward important and challenging reactions.In this work,we have proposed and validated unique Ni-O-Ce-O_(v)enriched Ni/CeO_(2)catalysts prepared by a deposition-precipitation method,for the transfer hydrogenation of lignin-derived guaiacol toward cyclohexanol rather than benzene derivatives.The counter-intuitively designed high Ni loading Ni_(2)0/CeO_(2)catalyst(20 wt%Ni content)displays a distance of 0.5 nm for Ni/O_(v)pairs with a remarkable activity(TOF:166.5 h^(-1))and 90%+selectivity for C_(Ar)=C_(Ar)bond saturation,outperforming better metal-dispersed Ni_(5)/CeO_(2)catalyst with limited presence of Ni-O-Ce-O_(v)sites.The high hydrogenation activity against hydrogenolysis reactions on Ni_(2)0/CeO_(2)catalyst is attributed to tunable Ni/O_(v)distances,which constrain the cleavage of CAr-OH bond and deep deoxygenation.Such spatial distribution effect has also facilitated tandem dehydrogenation(O-H bond cleavage)and hydrogenation(C_(Ar)=C_(Ar)hydrogenation)reactions,leading to cyclohexanol as the target product in the absence of externally added H_(2).Insights into spatial distribution of O_(v)sites open an alternative perspective in designing efficient catalysts toward producing value-added cyclic oxygenates through upgrading of lignin compounds. 展开更多
关键词 Non-noble catalyst spatial distribution Oxygen vacancy Guaiacol transfer hydrogenation CYCLOHEXANOL
在线阅读 下载PDF
Concentrations, spatial distribution, and human exposure of synthetic phenolic antioxidants in indoor dust from ten provinces in China
4
作者 Xueyu Weng Wanyi Wang +2 位作者 Qingqing Zhu Chunyang Liao Guibin Jiang 《Journal of Environmental Sciences》 2025年第6期584-593,共10页
Synthetic phenolic antioxidants(SPAs)are widely used in diverse industries due to their exceptional antioxidant characteristics.However,human exposure to SPAs may cause health problems.In this study,226 dust samples w... Synthetic phenolic antioxidants(SPAs)are widely used in diverse industries due to their exceptional antioxidant characteristics.However,human exposure to SPAs may cause health problems.In this study,226 dust samples were collected from 10 provinces in China,and six SPAs(three parent SPAs and their three transformation products)were analyzed.The concentrations of6SPAs(the sum of six target compounds)ranged from 15.4 to 3210 ng/g(geometric mean(GM):169 ng/g).The highest concentration of6SPAswas found in Sichuan Province(GM:349 ng/g),which was approximately 4 times higher than that in Hubei Province(81.6 ng/g)(p<0.05).The concentrations of butylated hydroxytoluene(BHT),2,2'-methylene bis(4-methyl-6–tert-butylphenol)(AO2246),2,6-di–tert–butyl–1,4-benzoquinone(BHT-Q),2,6-di–tert–butyl–4-(hydroxymethyl)phenol(BHT-OH),and ∑_(p)-SPAs were substantially higher in dust from urban areas than rural areas(p<0.05).AO2246 concentration in dust from homes(GM:0.400 ng/g)was about 4 times higher than that in workplaces(0.116 ng/g)(p<0.01).Significantly higherp-SPAs concentrations were found in dust from homes(GM:17.5 ng/g)than workplaces(11.4 ng/g)(p<0.01).The estimated daily intakes(EDIs)of ∑_(6)SPAs exposed through dust ingestion were 0.582,0.342,0.197,0.076,and 0.080 ng/kg bw/day in different age groups,and exposed through dermal contact was 0.358,0.252,0.174,0.167,and 0.177 ng/kg bw/day.EDIs showed that the exposure risks of SPAs decreased with age.This is the first work to determine SPAs in dust from10 provinces in China and investigate the spatial distribution of SPAs in those regions. 展开更多
关键词 Indoor dust Synthetic phenolic antioxidants spatial distribution Composition profile Human exposure
原文传递
Spatial and Temporal Distribution Characteristics of PM 10 Concentration in Yantai City and Its Relationship with Meteorological Factors
5
作者 Yumeng JIANG 《Meteorological and Environmental Research》 2025年第3期22-26,32,共6页
Based on the monitoring data of PM 10 concentration from six environmental monitoring stations and the ground meteorological observation data in Yantai City from 2019 to 2021,the spatial and temporal variation of PM 1... Based on the monitoring data of PM 10 concentration from six environmental monitoring stations and the ground meteorological observation data in Yantai City from 2019 to 2021,the spatial and temporal variation of PM 10 concentration and its relationship with meteorological factors were studied.The results show that from the perspective of temporal variation,the annual average of PM 10 concentration in Yantai City tended to decrease year by year.It was high in winter and spring and low in summer and autumn.In terms of monthly variation,the changing curve is U-shaped,and it was high in December and January but low in July and August.During a day,PM 10 concentration had two peaks.The first peak appeared approximately from 09:00 to 11:00,and the second peak can be found from 21:00 to 23:00.From the perspective of spatial distribution,PM 10 concentration was the highest in the development area and Fushan District.It was the highest in the west,followed by the east,while it was the lowest in the middle.The spatial difference rate was the highest in summer.Average temperature,relative humidity,wind speed and precipitation were the main meteorological factors influencing PM 10 concentration in Yantai area.PM 10 concentration was negatively correlated with average temperature and relative humidity,and the correlation was the most significant from June to October.It was negatively correlated with wind speed and precipitation,and the correlation was different in various months.The negative correlation was significant in summer and winter. 展开更多
关键词 Yantai City PM 10 spatial and temporal distribution Meteorological factors CORRELATION
在线阅读 下载PDF
Impacts of prolonged dry season and artificial food supply on the wintering spatial distribution of Siberian Cranes:Implications for conservation
6
作者 Deming Shen Fawen Qian +5 位作者 Shaoxia Xia Chaoyang Wang Xu Chu Zhenyu Wang Hongxing Jiang Yankuo Li 《Avian Research》 2025年第4期656-665,共10页
Poyang Lake,China's largest freshwater lake,is a critical wintering ground for most of the global Siberian Grane(Grus leucogeranus)population.However,increasingly prolonged dry seasons have degraded the natural we... Poyang Lake,China's largest freshwater lake,is a critical wintering ground for most of the global Siberian Grane(Grus leucogeranus)population.However,increasingly prolonged dry seasons have degraded the natural wetlands of Poyang Lake,forcing Siberian Cranes to shift to artificial habitats.From 2015 to 2023,field surveys revealed a substantial increase in the number of Siberian Cranes in artificial habitats,with peak counts reaching 3000individuals,accounting for up to 53%of the species'global population.Satellite telemetry of 13 individuals further confirmed the spatial use of these habitats,highlighting their consistent reliance on artificial sites over multiple years.Seven high-use hotspots were identified outside of Poyang Lake,including two artificial provisioning sites that supported dense foraging flocks for extended periods.Satellite telemetry confirmed this trend,with artificial habitats making up to 64.2%of the occurrence sites in some years.This reliance on artificial habitats was closely linked to the reduced tuber biomass in natural wetlands and low winter water levels in Poyang Lake,which collectively explained 83%of the variance in crane abundance in artificial habitats.Artificial habitat use peaked in December and January,indicating marked seasonal variation.Siberian Cranes also exhibited a pronounced circadian rhythm,foraging in artificial habitats during the day and returning to natural wetlands to roost at night.Despite the shift toward artificial habitats,natural wetlands remain critical for nighttime refuge.The continued dependence on artificial habitats raises concerns about disease transmission owing to dense congregations.Conservation strategies should prioritize both the careful management of artificial provisioning sites and the restoration of natural wetlands to improve food and habitat availability within natural ecosystems,ultimately enabling the return of Siberian Cranes to their traditional natural habitats. 展开更多
关键词 Artificial habitats Artificial provisioning Poyang lake Prolonged dry season Siberian crane spatial distribution
在线阅读 下载PDF
Spatial distribution changes and habitat conservation of medicinal plant diversity in the Yinshan Mountains(China)under climate change
7
作者 ZHAO Zeyuan BI Yaqiong +6 位作者 WEI Xinxin CHEN Yuan ZHANG Ru GUO Jingxia ZHANG Mingxu ZHANG Xiaobo LI Minhui 《Journal of Geographical Sciences》 2025年第7期1479-1496,共18页
Medicinal plant diversity(MPD)is an indispensable part of global plant diversity,serving as the foundation for human survival by offering remedies and preventive measures against diseases.However,factors such as overe... Medicinal plant diversity(MPD)is an indispensable part of global plant diversity,serving as the foundation for human survival by offering remedies and preventive measures against diseases.However,factors such as overexploitation,competition from invasive alien species,and climate change,threaten the habitats of medicinal plants,necessitating a comprehensive understanding of their spatial distribution and suitable habitats.We leveraged a decade of field survey data on medicinal plant distribution in the Yinshan Mountains,combined with spatial analysis,species distribution modeling,and the Carnegie Ames Stanford Approach(CASA)to explore the MPD spatial distribution and suitable habitats.Spatial analysis revealed that the central and eastern parts of Yinshan Mountains were the primary MPD hotspots,with no cold spots evident at various spatial scales.As the spatial scale decreased,previous non-significant regions transformed into hotspots,with instances where large-scale hotspots became insignificant.These findings offer valuable guidance for safeguarding and nurturing MPD across diverse spatial scales.In future climate change scenarios within the shared socioeconomic pathways(SSP),the habitat suitability for MPD in the Yinshan Mountains predominantly remains concentrated in the central and eastern regions.Notably,areas with high net primary productivity(NPP)values and abundant vegetation coverage align closely with MPD habitat suitability areas,potentially contributing to the region's rich MPD. 展开更多
关键词 medicinal plants diversity species distribution model climate change spatial analysis net primary productivity CASA model
原文传递
Spatial distribution and transport characteristics of river and sediment pollen in the middle and lower reaches of the Yellow River
8
作者 LIU Dexin PAN Yanfang +3 位作者 HE Xueli WU Pengfei MA Jianhua GU Lei 《Journal of Geographical Sciences》 2025年第3期552-576,共25页
This paper selects sampling sections for the mainstream and tributaries of the middle and lower reaches of the Yellow River,collects river water and sediment samples during the flood season for pollen analysis,and use... This paper selects sampling sections for the mainstream and tributaries of the middle and lower reaches of the Yellow River,collects river water and sediment samples during the flood season for pollen analysis,and uses methods such as Geodetector to explore the distribution characteristics and influencing factors of pollen.The results show significant variations in vegetation composition across different watersheds,leading to notable differences in both the percentage and concentration of pollen types.Pollen concentration in river water is generally higher in the mainstream compared to tributaries,while sediment pollen percentage and concentration are typically lower in the mainstream than in tributaries.The concentration of suspended solids is the most significant factor affecting pollen concentration in the Yellow River,with this effect being particularly prominent outside the Shanxi-Shaanxi Gorge.Abundant coarse sand and rapid flow velocities are likely responsible for the high suspended solids concentration and lower pollen concentration observed in the mainstream of the Shanxi-Shaanxi Gorge.In sediments,clay content is the primary factor influencing pollen concentration,and its interaction with silt and flow velocity has a more prominent influence on pollen concentration.At the Yellow River section below the Shanxi-Shaanxi Gorge,sediment pollen and clay concentrations significantly increase.The changes in pollen concentration in the river water before and after the reservoir are consistent with the suspended solids concentration,while the changes in sediment pollen concentration are consistent with the clay content.Notably,pollen concentrations in sediments decrease more significantly after passing through a reservoir compared to changes observed in river water samples.Overall,there is a strong correlation between river pollen and topsoil pollen,which can provide a reliable reflection of the broader vegetation landscape of the watershed.The findings can provide support for paleoenvironmental reconstruction using pollen from alluvial sediments or lakes with river inflows. 展开更多
关键词 river pollen sediment pollen spatial distribution transmission mechanism middle and lower reaches of the Yellow River
原文传递
Spatial distribution of shallow landslides caused by Typhoon Lekima in 2019 in Zhejiang Province, China 被引量:4
9
作者 CUI Yulong YANG Liu +1 位作者 XU Chong ZHENG Jun 《Journal of Mountain Science》 SCIE CSCD 2024年第5期1564-1580,共17页
In recent years, the coastal region of Southeast China has witnessed a significant increase in the frequency and intensity of extreme rainfall events associated with landfalling typhoons. The hilly and mountainous ter... In recent years, the coastal region of Southeast China has witnessed a significant increase in the frequency and intensity of extreme rainfall events associated with landfalling typhoons. The hilly and mountainous terrain of this area, combined with rapid rainfall accumulation, has led to a surge in flash floods and severe geological hazards. On August 10, 2019, Typhoon Lekima made landfall in Zhejiang Province, China, and its torrential rainfall triggered extensive landslides, resulting in substantial damage and economic losses. Utilizing high-resolution satellite images, we compiled a landslide inventory of the affected area, which comprises a total of 2,774 rainfallinduced landslides over an area of 2965 km2. The majority of these landslides were small to mediumsized and exhibited elongated, clustered patterns. Some landslides displayed characteristics of high-level initiation, obstructing or partially blocking rivers, leading to the formation of debris dams. We used the inventory to analyze the distribution pattern of the landslides and their relationship with topographical, geological, and hydrological factors. The results showed that landslide abundance was closely related to elevation, slope angle, faults, and road density. The landslides were predominantly located in hilly and low mountainous areas, with elevations ranging from 150 to 300 m, slopes of 20 to 30 degrees, and a NE-SE aspect. Notably, we observed the highest Landslide Number Density(LND) and Landslide Area Percentage(LAP) in the rhyolite region. Landslides were concentrated within approximately 4 km on either side of fault zones, with their size and frequency negatively correlated with distances to faults, roads, and river systems. Furthermore, under the influence of typhoons, regions with denser vegetation cover exhibited higher landslide density, reaching maximum values in shrubland areas. In areas experiencing significantly increased concentrated rainfall, landslide density also showed a corresponding rise. In terms of spatial distribution, the rainfall-triggered landslides primarily occurred in the northeastern part of the study area, particularly in regions characterized by complex topography such as Shanzao Village in Yantan Town, Xixia Township, and Shangzhang Township. The research findings offer crucial data on the rainfallinduced landslides triggered by Typhoon Lekima, shedding light on their spatial distribution patterns. These findings provide valuable references for mitigating risks and planning reconstruction in typhoon-affected area. 展开更多
关键词 Typhoon rainfall Landslide characteristics spatial distribution Southeast coastal region
原文传递
FPGA-based position reconstruction method for neutron beam flux spatial distribution measurement in BNCT 被引量:4
10
作者 Wei Jiang Ping Cao +5 位作者 Yi-Ming Wu Xian-Ke Liu Zhu-Jun Fang Zhi-Yong Zhang Bin Shi Jun Chen 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第3期96-108,共13页
A new measurement method for the spatial distribution of neutron beam flux in boron neutron capture therapy(BNCT)is being developed based on the two-dimensional Micromegas detector.To address the issue of long process... A new measurement method for the spatial distribution of neutron beam flux in boron neutron capture therapy(BNCT)is being developed based on the two-dimensional Micromegas detector.To address the issue of long processing times in traditional offline position reconstruction methods,this paper proposes a field programmable gate array based online position reconstruction method utilizing the micro-time projection chamber principle.This method encapsulates key technical aspects:a self-adaptive serial link technique built upon the dynamical adjustment of the delay chain length,fast sorting,a coordinate-matching technique based on the mapping between signal timestamps and random access memory(RAM)addresses,and a precise start point-merging technique utilizing a circular combined RAM.The performance test of the selfadaptive serial link shows that the bit error rate of the link is better than 10-12 at a confidence level of 99%,ensuring reliable data transmission.The experiment utilizing the readout electronics and Micromegas detector shows a spatial resolution of approximately 1.4 mm,surpassing the current method’s resolution level of 5 mm.The beam experiment confirms that the readout electronics system can obtain the flux spatial distribution of neutron beams online,thus validating the feasibility of the position reconstruction method.The online position reconstruction method avoids traditional methods,such as bubble sorting and traversal searching,simplifies the design of the logic firmware,and reduces the time complexity from O(n2)to O(n).This study contributes to the advancement in measuring neutron beam flux for BNCT. 展开更多
关键词 Position reconstruction FPGA Readout electronics Neutron flux spatial distribution
在线阅读 下载PDF
Comprehensive study on the spatial distribution of heavy metals and their environmental risks in high-sulfur coal gangue dumps in China 被引量:4
11
作者 Yingbo Dong Huan Lu Hai Lin 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2024年第2期486-497,共12页
The accumulation of coal gangue(CG)from coal mining is an important source of heavy metals(HMs)in soil.Its spatial distribution and environment risk assessment are extremely important for the management and remediatio... The accumulation of coal gangue(CG)from coal mining is an important source of heavy metals(HMs)in soil.Its spatial distribution and environment risk assessment are extremely important for the management and remediation of HMs.Eighty soil samples were collected from the high-sulfur CG site in northern China and analyzed for six HMs.The results showed that the soil was heavily contaminated by Mn,Cr and Ni based on the Nemerow index,and posed seriously ecological risk depended on the geo-accumulation index,potential ecological risk index and risk assessment code.The semi-variogram model and ordinary kriging interpolation accurately portrayed the spatial distribution of HMs.Fe,Mn,and Cr were distributed by band diffusion,Ni was distributed by core,the distribution of Cu had obvious patchiness and Zn was more uniform.The spatial autocorrelation indicated that all HMs had strong spatial heterogeneity.The BCR sequential extraction was employed to qualify the geochemical fractions of HMs.The data indicated that Fe and Cr were dominated by residual fraction;Cu,Ni and Zn were dominated by reducible and oxidizable fractions;Mn was dominated by reducible and acid-extractable(25.38%-44.67%)fractions.Pearson correlation analysis showed that pH was the main control factor affecting the non-residue fractions of HMs.Therefore,acid production from high sulfur CG reduced soil pH by 2-3,which indirectly promoted the activity of HMs.Finally,the conceptual model of HMs contamination at the CG site was proposed,which can be useful for the development of ecological remediation strategies. 展开更多
关键词 High-sulfur coal gangue Soil contamination Heavy metals spatial distribution Geochemical fractions Risk assessment
原文传递
Atmospheric VOCs in an industrial coking facility and the surrounding area:Characteristics,spatial distribution and source apportionment 被引量:2
12
作者 Meicheng Wen Weiqiang Deng +8 位作者 Jin Huang Shu Zhang Qinhao Lin ChaoWang Shengtao Ma Wanjun Wang Xin Zhang Guiying Li Taicheng An 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2024年第4期660-670,共11页
Industrial coking facilities are an important emission source for volatile organic compounds(VOCs).This study analyzed the atmospheric VOC characteristics within an industrial coking facility and its surrounding envir... Industrial coking facilities are an important emission source for volatile organic compounds(VOCs).This study analyzed the atmospheric VOC characteristics within an industrial coking facility and its surrounding environment.Average concentrations of total VOCs(TVOCs)in the surrounding residential activity areas(R1 and R2),the coking facility(CF)and the control area(CA)were determined to be 138.5,47.8,550.0,and 15.0μg/m^(3),respectively.The cold drum process and coking and quenching areas within the coking facility were identified as the main polluting processes.The spatial variation in VOCs composition was analyzed,showing that VOCs in the coking facility and surrounding areas were mainly dominated by aromatic compounds such as BTX(benzene,toluene,and xylenes)and naphthalene,with concentrations being negatively correlated with the distance from the coking facility(p<0.01).The sources of VOCs in different functional areas across the monitoring area were analyzed,finding that coking emissions accounted for 73.5%,33.3% and 27.7% of TVOCs in CF,R1 and R2,respectively.These results demonstrated that coking emissions had a significant impact on VOC concentrations in the areas surrounding coking facility.This study evaluates the spatial variation in exposure to VOCs,providing important information for the influence of VOCs concentration posed by coking facility to surrounding residents and the development of strategies for VOC abatement. 展开更多
关键词 Coking facility Volatile organic compounds Emission inventory spatial distribution Source apportionment
原文传递
Spatial distribution of soil salinization under the influence of human activities in arid areas,China 被引量:1
13
作者 LIU Yufang YANG Qingwen +5 位作者 PEI Xiangjun LI Jingji WANG Shuangcheng HUANG Zhenfu HAN Wei ZHENG Tianliang 《Journal of Arid Land》 SCIE CSCD 2024年第10期1344-1364,共21页
The Hotan Prefecture of Xinjiang Uygur Autonomous Region,China belongs to arid desert climate,with significant soil salinization issues.The study selected six rivers in Hotan Prefecture(Pishan,Qaraqash,Yurungqash,Cell... The Hotan Prefecture of Xinjiang Uygur Autonomous Region,China belongs to arid desert climate,with significant soil salinization issues.The study selected six rivers in Hotan Prefecture(Pishan,Qaraqash,Yurungqash,Celle,Kriya,and Niya rivers)to explore the spatial distribution of soil salinization in this area and its underlying mechanisms.Sampling was conducted along each river's watershed,from the Gobi in the upper reaches,through the anthropogenic impact area in the middle reaches,to the desert area in the lower reaches.Soil physical-chemical indicators,including total soluble salts,pH,K+,Na+,Ca2+,Mg2+,SO42-,Cl-,CO32-,HCO3-,organic matter,available nitrogen,available phosphorus,and available potassium,were tested,along with the total dissolved solids of surface water and groundwater.The results revealed that the soil water and nutrient contents in anthropogenic impact area were higher than those in Gobi and desert areas,while the pH and total soluble salts were lower than those in Gobi and desert areas.The ions in the soil of the study area were primarily Cl-,SO42-,K+,and Na+,and the ion concentration of soil salt were positively correlated with surface water and groundwater.Overall,the study area exhibited low soil water content,low clay content,infertile soil,and high soil salinization,dominated by weak to moderate chloride-sulfate types.Compared with Gobi and desert areas,the soil in anthropogenic impact area had higher soil water content,lower pH,lower soluble salts,and higher nutrients,indicating that human farming activities help mitigate salinization.These findings have practical implications for guiding the scientific prevention and control of soil salinization in the arid areas and for promoting sustainable agricultural development. 展开更多
关键词 soil salinization human activities spatial distribution Hotan Prefecture soil soluble salt soil nutrient
在线阅读 下载PDF
Spatial Grasp Model for Distributed Management and Its Comparison With Traditional Algorithms
14
作者 Peter Simon Sapaty 《International Relations and Diplomacy》 2025年第3期164-179,共16页
The word“spatial”fundamentally relates to human existence,evolution,and activity in terrestrial and even celestial spaces.After reviewing the spatial features of many areas,the paper describes basics of high level m... The word“spatial”fundamentally relates to human existence,evolution,and activity in terrestrial and even celestial spaces.After reviewing the spatial features of many areas,the paper describes basics of high level model and technology called Spatial Grasp for dealing with large distributed systems,which can provide spatial vision,awareness,management,control,and even consciousness.The technology description includes its key Spatial Grasp Language(SGL),self-evolution of recursive SGL scenarios,and implementation of SGL interpreter converting distributed networked systems into powerful spatial engines.Examples of typical spatial scenarios in SGL include finding shortest path tree and shortest path between network nodes,collecting proper information throughout the whole world,elimination of multiple targets by intelligent teams of chasers,and withstanding cyber attacks in distributed networked systems.Also this paper compares Spatial Grasp model with traditional algorithms,confirming universality of the former for any spatial systems,while the latter just tools for concrete applications. 展开更多
关键词 spatial awareness spatial control spatial consciousness spatial Grasp Technology spatial Grasp Language spatial scenarios cyber attacks distributed algorithms mobile agents
在线阅读 下载PDF
Impacts of China's natural forest protection project on habitat distribution of key protected birds in the Qinghai-Tibet Plateau
15
作者 Changli Bu Wendong Xie +4 位作者 Zihe Ma Yifei Wang Yun Fang Kai Song Yue-Hua Sun 《Avian Research》 2025年第2期159-165,共7页
The Natural Forest Protection Project(NFPP),initiated by the Chinese government in 2000,is a crucial ecological construction project that has played a significant role in forest restoration in China.Forests in the Qin... The Natural Forest Protection Project(NFPP),initiated by the Chinese government in 2000,is a crucial ecological construction project that has played a significant role in forest restoration in China.Forests in the Qinghai-Tibet Plateau(QTP)serve as important habitats for many rare and endemic birds.Understanding the conservation efficiency of NFPP implementation on these birds holds significant practical significance.In this study,we utilized land use change matrices to analyze the forest changes in the QTP before and after NFPP implementation,predicted the potential spatial distribution of 16 nationally protected birds using Species Distribution Models(SDMs),and compared the impacts of this project on bird habitats under different carbon emission scenarios.Mann-Whitney U tests were employed to analyze the adaptation of different birds to forest changes during NFPP implementation.Our results showed that NFPP protected 172,398 km^(2) of primary forests and added 6379 km^(2) of secondary forests in our study area.The potential spatial distribution and sympatric species richness of the 16 protected birds slightly increased after NFPP implementation under different climate change scenarios,and NFPP implementation contributed to improving the potential spatial distribution of birds.Compared to newly established secondary forests,protected primary forests exhibited enhanced conservation for forest birds(Z-value>0 for six bird species,P<0.1),while being less suitable for non-forest birds(significantly unsuitable for three non-forest bird species,Z-value<0,P<0.05;non-significantly unsuitable for four non-forest bird species,Zvalue<0,P>0.1).This indicates that the protection of primary forests during NFPP implementation benefits forest bird conservation while the addition of secondary forests is beneficial to non-forest birds.To enhance the role of NFPP in avian conservation in the QTP,it is suggested to increase the landscape heterogeneity of forest,particularly in newly established secondary forests. 展开更多
关键词 Bird conservation Climate change NFPP Potential spatial distribution QTP
在线阅读 下载PDF
Scyphozoa,Hydrozoa,and Ctenophora biodiversity and distribution patterns in the Xisha Islands revealed by environmental DNA metabarcoding
16
作者 Tingting SUN Lijing YE +4 位作者 Lei WANG Saijun PENG Wenjing ZHANG Jianmin ZHAO Zhijun DONG 《Journal of Oceanology and Limnology》 2025年第5期1515-1527,共13页
Coral reefs support a wide range of organisms in the world,including jellyfish and their benthic relatives.However,quantifying the biodiversity of these organisms in reefs is a challenge because of their uneven distri... Coral reefs support a wide range of organisms in the world,including jellyfish and their benthic relatives.However,quantifying the biodiversity of these organisms in reefs is a challenge because of their uneven distribution and cryptic early life stages,requiring the validation of alternative techniques for biodiversity assessment.Here,the biodiversity and spatial distribution patterns of jellyfish and their benthic relatives,from the Scyphozoa,Hydrozoa,and Ctenophora taxa(hereafter referred to as SHC),were investigated in the coral reefs of Xisha,China,using environmental DNA(eDNA)metabarcoding technology by collecting shallow seawater,mesophotic seawater,and sediment samples.One-hundred and eighty-eight SHC species spanning two phyla(Cnidaria and Ctenophora),three classes,11 orders,65 families,and 104 genera were identified,among which hydrozoans were the most dominant taxa,accounting for 89.81% of all SHC species.SHC species showed low connectivity between shallow and mesophotic habitats,presenting a clear vertical distribution pattern in coral reefs.In the mesophotic coral ecosystems(MCEs),140 SHC species(84.34%)were detected,of which 39.76% were exclusive to MCEs,with Zanclea sp.1,Orthopyxis integra,and Fabienna sphaerica being the dominant species.Additionally,although SHC diversity in seawater was higher than that in the sediment samples,22 species were identified only in the sediment samples,indicating that sediment eDNA may represent a valuable supplementary tool for the investigation of SHC communities in hot spots.In addition to revealing the vast diversity of SHC species occupying coral reef ecosystems in the Xisha Islands,our findings confirm the potential of eDNA metabarcoding as an advanced tool for monitoring the biodiversity of cryptic species. 展开更多
关键词 eDNA metabarcoding mesophotic coral ecosystem BIODIVERSITY spatial distribution
在线阅读 下载PDF
Spatiotemporal distribution of GNSS-derived PWV in Australia from 2010 to 2019
17
作者 Pan Zhao Fuyang Ke +1 位作者 Haopeng Wu Min Wei 《Geodesy and Geodynamics》 2025年第4期454-464,共11页
The weather in Australia is significantly influenced by water vapor evaporated fromwarm ocean surfaces,which is closely associated with various extreme weather events in the region,such as floods,droughts,and bushfire... The weather in Australia is significantly influenced by water vapor evaporated fromwarm ocean surfaces,which is closely associated with various extreme weather events in the region,such as floods,droughts,and bushfires.This study utilizes Precipitable Water Vapor(PWV)data from 15 Global Navigation Satellite System(GNSS)stations spanning 2010 to 2019 to investigate the spatiotemporal distribution of atmospheric water vapor across Australia,aiming to improve the accuracy of forecasting hazardous weather events.The results indicate distinct regional features in the spatial distribution of PWV.PWV gradually decreases from coastal areas toward inland regions and increases from south to north.Temporally,the overall trend of PWV remains consistent.From an annual trend perspective,most areas exhibit a decline in PWV content,with the exception of the southwestern coastal region,which shows an increasing trend.Furthermore,the study explores the correlations between PWV content and elevation,latitude,and longitude.Among these,latitude demonstrates the strongest correlation with PWV,with a correlation coefficient as high as 0.88,highlighting the significant impact of latitude on water vapor distribution. 展开更多
关键词 AUSTRALIA GNSS-derived PWV spatial distribution characteristics Multi-scale analysis Climate variability
原文传递
Seasonal Distribution and Mechanism of Chlorophyll-a in Beibu Gulf
18
作者 CHEN Yanyu ZHAO Xin +4 位作者 GU Weifang BAO Xianwen LIU Zhen CHEN Bo SHI Maochong 《Journal of Ocean University of China》 2025年第5期1182-1194,共13页
This study used moderate-resolution imaging spectroradiometer(MODIS)data and a high-resolution unstructured grid finite volume community ocean model(FVCOM)to investigate the seasonal and regional characteristics of ph... This study used moderate-resolution imaging spectroradiometer(MODIS)data and a high-resolution unstructured grid finite volume community ocean model(FVCOM)to investigate the seasonal and regional characteristics of physical and ecological elements in the Beibu Gulf.The findings reveal that,in the Beibu Gulf,strong temperature gradients exist in winter,with sea surface temperatures becoming uniform at around 30℃ in summer.Sea surface salinity is influenced by low-salinity water from the Qiongzhou Strait and rivers,as well as high-salinity water from the open sea,reaching its minimum levels in autumn.Chlorophyll-a(Chl-a)concentrations peak in nearshore areas,particularly in autumn.In the Beibu Gulf,a significantly negative partial correlation exists between sea surface temperature and Chl-a(ρ=-0.5).Furthermore,wind patterns exert a considerable influence on different re-gions outside the eastern Beibu Gulf(|ρ|≥0.49),particularly showing a negative correlation along the Vietnamese coast.Cooling-in-duced water instability,coupled with wind-driven upwelling,enhances vertical water movement,thus facilitating the upward trans-port of nutrients.High Chl-a concentrations in the estuarine area are attributed to the nutrient-rich discharges(ρ=0.55)and the strong estuarine gravity circulation induced by intense density gradients.There are also notably high Chl-a concentrations in the eastern Beibu Gulf and the western coast of Hainan Island despite the presence of adverse environmental conditions.These anomalies can be attributed to wind-induced upwelling and tidal mixing front-induced upwelling,respectively.This study presents a comprehensive analysis of the distribution and mechanisms of Chl-a in the Beibu Gulf,thus highlighting the complex interactions among various fac-tors and emphasizing the importance of local environmental conditions. 展开更多
关键词 the Beibu Gulf CHLOROPHYLL-A temporal and spatial distribution SST UPWELLING the river discharge
在线阅读 下载PDF
Global distributions and long-term trends of available wave energy based on ERA5 wave reanalysis
19
作者 Jian Shi Wei Liu +5 位作者 Haifei Sun Xiangming Cao Yuan Li Chi Zhang Nguyen Viet Thanh Lipeng Zhang 《Acta Oceanologica Sinica》 2025年第6期15-32,共18页
Using the ERA5 wave reanalysis,the distributions and trends of global available wave energy storage during 1980−2019 are analyzed.The results show that the available wave energy storage is not only related to total wa... Using the ERA5 wave reanalysis,the distributions and trends of global available wave energy storage during 1980−2019 are analyzed.The results show that the available wave energy storage is not only related to total wave energy storage but is also affected by the local available wave probability.Different distributions and trends between the available wave energy and total wave energy storage are observed.Larger values of total wave energy storage are concentrated in the high-latitude westerlies zone,whereas available wave energy storage exhibits greater concentration in the middle-low latitude regions.In each basin,there is a notable upward trend in both total wave energy storage and available wave energy storage.However,the northern Hemisphere(NH)exhibits an increasing trend in available wave probability,whereas the southern Hemisphere(SH)experiences a decreasing trend.This divergence contributes to the spatial distributions of available wave energy storage becoming increasingly uniform.These trends in wave energy are primarily influenced by changes in significant wave height.Although the increasing trend of significant wave height across all frequency ranges induces the growth of total wave energy storage,only the increasing of wave heights falling in 1.3−4 m can cause the growth of available wave energy storage.The consistent increasing rates of wave height under different mean levels contribute to the divergent trends in available wave probability. 展开更多
关键词 ERA5 available wave energy spatial distribution long-term trends wave energy converter
在线阅读 下载PDF
Analysis of the distribution of sound velocity profiles and sound propagation laws based on a global high-resolution ocean reanalysis product
20
作者 Shiyuan Tao Yi Yu +2 位作者 Wenbin Xiao Weimin Zhang Yanlai Zhao 《Acta Oceanologica Sinica》 2025年第5期131-149,共19页
Ocean reanalysis data,compared to traditional observational data,possess stronger continuity and higher data accuracy.The globally high-resolution ice-ocean coupled reanalysis product China Ocean ReAnalysis,Version 2.... Ocean reanalysis data,compared to traditional observational data,possess stronger continuity and higher data accuracy.The globally high-resolution ice-ocean coupled reanalysis product China Ocean ReAnalysis,Version 2.0(CORA v2.0),independently developed by the National Marine Information Center,has attracted considerable attention since its release in 2020.This study selected six representative points of sound velocity profiles in different global ocean regions and conducted comparative analysis between the 2014 momentary data from CORA v2.0 and Argo data.Additionally,the monthly average data of CORA v2.0 in 2013 were compared and studied against General Digital Environmental Model(GDEM)and World Ocean Atlas(WOA)data.Metrics such as Root Mean Square Error(RMSE)and Mean Error(ME)were introduced to evaluate the differences between datasets.The result reveals that,in a comparison of single moment data,the sound velocity profiles of CORA v2.0 data and Argo data exhibit high consistency,with ME generally within 2 m/s.Regarding a comparison of monthly average data,the consistency between CORA v2.0 data and WOA data is higher,while the error relative to GDEM data is relatively larger,but their RMSE and ME exhibit high similarity in temporal trends.Based on the 2014 data of CORA v2.0,the temporal and spatial evolutionary laws of global seawater sound velocity profiles and sound speed fields were analyzed.On the time scale,the variation of seawater sound speed is mainly influenced by seasons,with significant differences between winter and summer seasons.On the daily scale,there are certain differences in sound velocity profiles mainly in the early morning and afternoon.On the spatial scale,analysis was conducted from both horizontal and vertical perspectives.The distribution of sound speed exhibits evident regularity with latitude,with shallow seawater sound speed being greatly influenced by external factors while deep seawater is relatively stable.Using the Range-dependent Acoustic Model for Geoacoustics(RAMgeo)model to solve the underwater acoustic field at three specific points,the characteristic changes of sound velocity profiles at different times of the day and their impact on under water sound propagation losses were obtained.This paper provides valuable information for the application of CORA v2.0 data products. 展开更多
关键词 ocean reanalysis products sound velocity profile temporal and spatial distribution characteristics
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部