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How topography and neighbor shape the fate of trees in subtropical forest restoration:Environmental filtering and resource competition drive natural regeneration
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作者 Haonan Zhang Xingshuo Zhang +7 位作者 Yingying Lv Yanyan Ni Baokun Xu Xiangnan Han Xiao Cao Qingpei Yang Wanggu Xu Zhedong Qian 《Forest Ecosystems》 SCIE CSCD 2024年第1期73-86,共14页
The structure of plant communities at local scales depends on both the spatial heterogeneity of abiotic environmental factors and the biotic interactions within the community.However,although environmental filtering d... The structure of plant communities at local scales depends on both the spatial heterogeneity of abiotic environmental factors and the biotic interactions within the community.However,although environmental filtering due to microtopographic heterogeneity and resource competition among plants caused by spatial variation in tree density and size are considered to be very important in explaining the mechanisms of community assembly,their effects on the processes of individual mortality and recruitment in natural forest regeneration,as well as their relative contributions,are still poorly understood.To address this,we established a 12-ha permanent plot in a subtropical evergreen broad-leaved forest area and measured microtopographic variables such as elevation,slope,aspect,and terrain position index(TPI)using a total station.We monitored the individual mortality and recruitment in forest natural regeneration through repeated surveys at 5-year intervals.We fitted spatial covariance models to jointly use multiple factors from three groups of variables(microtopographic effect,neighborhood density effects,neighborhood size effects)as explanatory variables to analyze their roles in driving the mortality and recruitment of all individual and 12 dominant species in forest natural regeneration at the neighborhood scale.Our results show that:(1)In the crucial early stages of secondary forest restoration,natural regeneration is influenced by a synergy of environmental filtering,due to microtopographic heterogeneity,and resource competition among plants.(2)For distinct species responses,evergreen dominant species'mortality is largely explained by neighborhood effects,while deciduous species are more affected by topographic factors.Furthermore,the adverse effects of larger conspecific trees on younger trees indicate a pattern of competitive pressure leading to mortality among regenerating trees,such pattern emphasis the influence of parent trees on natural regeneration.(3)As trees grow,their interaction with these stressors evolves,suggesting a shift in their resource acquisition strategies and response to neighborhood effects and environmental factors.Despite these changes,the relative importance of topographic factors in determining survival and recruitment success remains constant.This research highlights the importance of considering both environmental and neighborhood effects in forest management,particularly in early secondary forest restoration. 展开更多
关键词 Natural regeneration MICROTOPOGRAPHY Neighborhood effects Mortality and recruitment
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A Comparative Analysis of Environmental Quality Assessment Methods for Heavy Metal-Contaminated Soils 被引量:33
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作者 LI Wei-Xin ZHANG Xu-Xiang +5 位作者 WU Bing SUN Shi-Lei CHEN Yan-Song PAN Wen-Yang ZHAO Da-Yong CHENG Shu-Pei 《Pedosphere》 SCIE CAS CSCD 2008年第3期344-352,共9页
Four assessment methods (two pollution indexes and two fuzzy mathematical models) were employed to investigate the environmental quality of four soils around a ferroalloy plant in Nanjing City. Environmental quality... Four assessment methods (two pollution indexes and two fuzzy mathematical models) were employed to investigate the environmental quality of four soils around a ferroalloy plant in Nanjing City. Environmental quality was assessed as class Ⅳ (moderately polluted) for each soil with single-factor index method, and was identified to be classes Ⅳ, Ⅲ (slightly polluted), Ⅲ, and Ⅲ for soils A, B, C, and D, respectively, with the comprehensive index model. In comparison with the single-factor index method, the comprehensive index model concerned both dominant parameter and average contribution of all factors to the integrated environmental quality. Using the two fuzzy mathematical methods (single-factor deciding and weighted average models), the environmental risks were determined to be classes Ⅳ, Ⅲ, Ⅱ (clean), and Ⅱ for soils A, B, C, and D, respectively. However, divergence of the membership degree to each pollution class still occurred between the two methods. In fuzzy mathematical methods, membership functions were used to describe the limits between different pollution degrees, and different weights were allocated for the factors according to pollution contribution. Introduction of membership degree and weight of each factor to fuzzy mathematical models made the methods more reasonable in the field of environmental risk assessment. 展开更多
关键词 environmental assessment fuzzy mathematical model heavy metal pollution pollution index method SOIL
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Environmental Geochemistry of Heavy Metal Contaminants in Soil and Stream Sediment in Panzhihua Mining and Smelting Area,Southwestern China 被引量:15
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作者 滕彦国 庹先国 +2 位作者 倪师军 张成江 徐争启 《Chinese Journal Of Geochemistry》 EI CAS 2003年第3期253-262,共10页
Mining and smelting activities are the main causes for the in creasing pollution of heavy metals in soil, water body and stream sediment. An e nvironmental geochemical investigation was carried out in and around the P... Mining and smelting activities are the main causes for the in creasing pollution of heavy metals in soil, water body and stream sediment. An e nvironmental geochemical investigation was carried out in and around the Panzhih ua mining and smelting area to determine the extent of chemical contamination in soil and sediment. The main objective of this study was to investigate the envi ronmental geochemistry of Ti, V, Cr, Mn, Cu, Pb, Zn and As in soil and sediment and to assess the degree of pollution in the study area. The data of heavy metal concentrations reveal that soils and sediments in the area have been slightly c ontaminated. Geochemical maps of I\-\{geo\} of each heavy metal show that the co ntaminated sites are located in V-Ti-magnetite sloping and smelting, gangues d am. The pollution sources of the selected elements come mainly from dusts result ant from mining activities and other three-waste-effluents. The area needs to be monitored regularly for trace metal, especially heavy metal enrichment. 展开更多
关键词 环境地球化学 重金属污染 土壤污染 河流沉积 攀枝花市 采矿业 熔炼
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Effects of Environmental Lead Pollution on Blood Lead and Sex Hormone Levels among Occupationally Exposed Group in An E-waste Dismantling Area 被引量:5
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作者 YANG Yan LU Xiao Song +1 位作者 LI Ding Long YU Yun Jiang 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2013年第6期474-484,共11页
Objective To study the effects of environmental multi-media lead pollution on blood lead and sex hormone levels among lead exposed males engaged in E-waste dismantling, and the correlation between confounding factors ... Objective To study the effects of environmental multi-media lead pollution on blood lead and sex hormone levels among lead exposed males engaged in E-waste dismantling, and the correlation between confounding factors and sex hormone levels. Methods An E-waste dismantling area in Taizhou of Zhejiang Province was selected as the research site. One hundred and fifty two samples were collected from the groundwater, soil, rice, corn, chicken, and pork in the dismantling area. The effects of the multi-media lead pollution on the male blood lead and sex hormone levels of FSH, LH, and T, as well as the correlation with confounding factors, were studied. Results The blood lead concentrations in the males aged under 31, from 31 to 45 and from 46 to 60 were 98.55, 100.23, and 101.45 I~/L, respectively. Of all the environmental media lead exposures, the groundwater, rice and soil were main contributing factors to the lead accumulation in humans. FSH and LH levels increased with the age while the T levels decreased with the age instead. There was a significant correlation between the FSH and LH levels and wearing masks. Conclusion There was correlation between the FSH, LH, and T levels, and the mean values of lead concentrations in environmental media, and the sex hormone levels were correlated with the confounding factor of wearing masks. 展开更多
关键词 Lead E-waste dismantling Follicle stimulating hormone (FSH) Luteinizing hormone (LH) Testosterone (T) Blood lead
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Study on the Post-evaluation of Environmental Planning Based on Logical Framework Approach 被引量:2
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作者 CHEN Yu-xian DONG Ze-qin 《Meteorological and Environmental Research》 CAS 2011年第2期1-5,9,共6页
[Objective] The aim was to conduct post-evaluation on environmental planning by means of logical framework approach. [Method] Taking environmental planning during '11th Five-year Plan' in a certain province fo... [Objective] The aim was to conduct post-evaluation on environmental planning by means of logical framework approach. [Method] Taking environmental planning during '11th Five-year Plan' in a certain province for example, by means of logical framework approach (LFA), the post-evaluation on environmental planning was carried out from the aspects of evaluation content, index system, implementation steps, evaluation feedback and input-output analysis of environmental planning. [Result] The post-evaluation on environmental planning by means of LFA achieved expected purpose and various indexes at different stages of environmental planning was assessed, and then corresponding countermeasures were put forward according to the problems which were found by problem tree of environmental planning project. [Conclusion] The study could provide theoretical references for the post-evaluation on environmental planning in future. 展开更多
关键词 Logical framework approach Environmental planning during '11th Five-year Plan' POST-EVALUATION China
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Integrated water risk early warning framework of the semi-arid transitional zone based on the water environmental carrying capacity (WECC)
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作者 XIE Yuxi ZENG Weihua QIU Jie 《Journal of Arid Land》 SCIE CSCD 2023年第2期145-163,共19页
Water risk early warning systems based on the water environmental carrying capacity(WECC)are powerful and effective tools to guarantee the sustainability of rivers.Existing work on the early warning of WECC has mainly... Water risk early warning systems based on the water environmental carrying capacity(WECC)are powerful and effective tools to guarantee the sustainability of rivers.Existing work on the early warning of WECC has mainly concerned the comprehensive evaluation of the status quo and lacked a quantitative prejudgement and warning of future overload.In addition,existing quantitative methods for short-term early warning have rarely focused on the integrated change trends of the early warning indicators.Given the periodicity of the socioeconomic system,however,the water environmental system also follows a trend of cyclical fluctuations.Thus,it is meaningful to monitor and use this periodicity for the early warning of the WECC.In this study,we first adopted and improved the prosperity index method to develop an integrated water risk early warning framework.We also constructed a forecast model to qualitatively and quantitatively prejudge and warn about the development trends of the water environmental system.We selected the North Canal Basin(an essential connection among the Beijing-Tianjin-Hebei region)in China as a case study and predicted the WECC in 25 water environmental management units of the basin in 2018–2023.We found that the analysis of the prosperity index was helpful in predicting the WECC,to some extent.The result demonstrated that the early warning system provided reliable prediction(root mean square error of 0.0651 and mean absolute error of 0.1418),and the calculation results of the comprehensive early warning index(CEWI)conformed to the actual situation and related research in the river basin.From 2008 to 2023,the WECC of most water environmental management units in the basin had improved but with some spatial differences:the CEWI was generally poor in areas with many human disturbances,while it was relatively good in the upstream regions with higher forest and grass covers as well as in the downstream areas with larger water volume.Finally,through a sensitivity analysis of the indicators,we proposed specific management measures for the sustainability of the water environmental system in the North Canal Basin.Overall,the integrated water risk early warning framework could provide an appropriate method for the water environmental administration department to predict the WECC of the basin in the future.This framework could also assist in implementing corresponding management measures in advance,especially for the performance evaluation and the arrangement of key short-term tasks in the River Chief System in China. 展开更多
关键词 water risk early warning system water environmental carrying capacity prosperity index water management North Canal(Beiyun River)
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Optical Characteristics of Chromophoric Dissolved Organic Matter(CDOM)in Upstream and Downstream Lakes of Taihu Lake Basin:New Insights for Water Environmental Management
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作者 REN Weixiang WU Xiaodong +4 位作者 CHEN Bingfa CHAO Jianying GE Xuguang YANG Jiuyun YANG Hui 《Chinese Geographical Science》 SCIE CSCD 2022年第4期606-619,共14页
Chromophoric dissolved organic matter(CDOM)is a key component of organic matter that contributes to the ecological functioning of lakes.The lakes in Taihu Lake Basin play an important role in maintaining regional ecol... Chromophoric dissolved organic matter(CDOM)is a key component of organic matter that contributes to the ecological functioning of lakes.The lakes in Taihu Lake Basin play an important role in maintaining regional ecological stabilities;however,the optical characteristics of the CDOM in the upstream and downstream lakes in this basin have not yet been systematically studied.Here,the optical characteristics of CDOM in ten lakes of upstream and downstream of the Taihu Lake Basin were studied using UV-Visible and excitation-emission matrix spectroscopies.Three different fluorophores consisting of two humic-like components(C1,C2)and one protein-like component(C3)were identified by parallel factor analysis.Soil or surface erosion was responsible for the higher abund-ance of C1 in the upstream lakes,and increased biological activities accounted for the higher abundance of C3 in the downstream lakes.Rainfall erosion in the wet season led to an increase in CDOM.We also found that the photodegradation and flocculation degree,which played a significant role in reducing CDOM,were higher in downstream lakes than in upstream lakes.Optical analysis of CDOM provides a promising method for monitoring water qualities(e.g.,total phosphorus and potassium permanganate index)in each lake.Re-ductions in soil or surface erosion in the upstream are needed to improve water quality. 展开更多
关键词 Taihu Lake Basin chromophoric dissolved organic matter(CDOM) excitation-emission spectra parallel factor analysis(PARAFAC)
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New Normal of Environmental Protection: Our Responsibility and Action
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作者 Zhang Xiuyu Li Yuan +3 位作者 Yang Ziyi Zhi Jiangyu Wang Zhongyang Peng Xiaochun 《Meteorological and Environmental Research》 CAS 2016年第3期45-48,共4页
It has become the hot topic of new normal for environmental protection to " impel ecological civilization and create new way of environ- mental protection". In this paper, based on current severe environmental prote... It has become the hot topic of new normal for environmental protection to " impel ecological civilization and create new way of environ- mental protection". In this paper, based on current severe environmental protection situation, new idea of "government taking the stage, research department writing a play,enterprise acting in an opera and the masses supervising" and action plan of "government having the right but can not be impulsive, research department having the talent and should discharge their duties, enterprise having the money but should keep law, and the mas- ses having the enthusiasm to strengthen supervision" for environmental protection are proposed,which aims to contribute ideas and exert efforts for impelling ecological civilization and environmental protection. 展开更多
关键词 Environmental protection Ecological civilization Beautiful China RESPONSIBILITY Action China
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Tendency and Control Strategy of Agricultural Environmental Pollution in China
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作者 Qiuping Han Zhencheng Xu +2 位作者 Zhenyuan Guo Xibang Hu Dong Zeng 《Meteorological and Environmental Research》 CAS 2013年第7期35-38,共4页
Current situation of China's agricultural pollution was elaborated, and the causes of the pollution were analyzed. Moreover, China's agri- cultural pollution tendency in the next few years was predicted. In order to... Current situation of China's agricultural pollution was elaborated, and the causes of the pollution were analyzed. Moreover, China's agri- cultural pollution tendency in the next few years was predicted. In order to control agricultural pollution in China, we should construct a diet structure for health and ecological civilization and create an ecological food chain by establishing a new concept of diet. 展开更多
关键词 Agricultural pollution DIET ECOLOGY Transformation and upgrade China
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Research on Environmental Impact Assessment Methods of Farmland Improvement along Coastal Areas of Jiangsu Province
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作者 LIU Liu CHEN Yan +2 位作者 ZHOU Kou-hong ZHANG Xing HUANG Dong-qin 《Meteorological and Environmental Research》 CAS 2012年第10期36-39,42,共5页
[ Objective] The study aimed to assess the impact of farmland improvement on ecological environment along coastal areas of Jiangsu Province. [ Method] Taking the coastal farmland improvement of Sheyang County, Jiangsu... [ Objective] The study aimed to assess the impact of farmland improvement on ecological environment along coastal areas of Jiangsu Province. [ Method] Taking the coastal farmland improvement of Sheyang County, Jiangsu Province as an example, an indicator system of environ- mental impact assessment (EIA) for coastal farmland improvement was established based on data collection, field survey and monitoring results, expert consultation, literature study and other methods, including four subsystems (biological resource, soil, vegetation and water environment) and 12 indicators. [ Result] The weights of soil, biological resource, vegetation and water environment were 0.614, 0.219, 0.118 and 0.049, and the top weight of soil showed that farmland improvement had a great influence on soil. Among the 12 indicators, the most important indicators with higher weights were reclamation rate of the land (weight 0.389), population density (weight 0.164) and the content of soil organic matter (weight 0.088). Therefore, in EIA of such kind of projects in the future, we should give prominence to the identification, evaluation and monitoring of the main characteristic factor above. [ Conclusion] The research could provide scientific references for the sustainable utilization of resources and estab- lishment of environmental management policies along costal areas of Jiangsu Province. 展开更多
关键词 Jiangsu coast Farmland improvement Ecological impact Indicator system Sheyang County China
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Holocene environmental change according to lake core in Fildes Peninsula of King George Island,Antarctica
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作者 李小梅 袁宝印 赵俊琳 《Chinese Journal of Polar Science》 2002年第2期137-144,共8页
Lake core sampled from Xihu in Fildes Peninsula of King Gorge Island, Antarctica could reveal the environmental change of the district. The lake core( GA7) , 9.28 meters long , was sectioned at an interval of 2 cm. Th... Lake core sampled from Xihu in Fildes Peninsula of King Gorge Island, Antarctica could reveal the environmental change of the district. The lake core( GA7) , 9.28 meters long , was sectioned at an interval of 2 cm. Through measuring the organic carbon, magnetic susceptibility, granularity and organic carbon isotope of GA7, by use of 14C age it was estimated that there were four periods of high temperature in Fildes Peninsula; 4800-4400 aB. P. , 3600-3350 aB. P. ,2100 - 1800 aB. P. and 900 aB. P. - present. Meanwhile, results showed that there was a strikingly positive correlation between the content of organic carbon and that of organic carbon isotope (δC01213 ) which could be the substitute indicators of environmental temperature. 展开更多
关键词 ANTARCTICA HOLOCENE environmental change
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The progress of strategic environmental assessment (SEA): Studies and practices in the mainland, Hong Kong and Taiwan of China
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作者 WANG Zhi-gang CHEN Xin-geng +2 位作者 SHANG Jin-cheng WU Ren-hai CHEN Bing-lu 《Journal of Environmental Science and Engineering》 2007年第1期8-18,共11页
Strategic environmental assessment (SEA) is the process to evaluate, in a systematic way, the possible environmental impacts caused by decision making such as policy, plan, and program. It is of highly significance ... Strategic environmental assessment (SEA) is the process to evaluate, in a systematic way, the possible environmental impacts caused by decision making such as policy, plan, and program. It is of highly significance to improve decision-making. This article reviewed the researches on SEA as well as its practices in Taiwan, Hong Kong and the mainland of China. The regulations, methodologies, and effect of practices were compared. The regulations on SEA had been enacted at three places respectively. With the largest spatial area and rapid economic development pace, the mainland has carded out more SEA practices recently than the other two places, but their final effect still need to be confirmed. It was said that Hong Kong had acquired considerable experiences on SEA, while practice of SEA at Taiwan lagged behind. 展开更多
关键词 MAINLAND Hong Kong TAIWAN strategic environmental assessment (SEA) practice
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Epiphytic zooplankton community profiles in a typical urban wetland as revealed by DNA metabarcoding
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作者 Diwen LIANG Chunrong HUANG +3 位作者 Senjie LIN Jiahua DONG Mingyi LIANG Hailin LUO 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第5期1571-1585,共15页
Zooplankton,a crucial component of urban wetland,are one of the effective bioindicators for monitoring the feeding stocks of organisms at higher trophic levels and assessing the ecological quality of ecosystems.Howeve... Zooplankton,a crucial component of urban wetland,are one of the effective bioindicators for monitoring the feeding stocks of organisms at higher trophic levels and assessing the ecological quality of ecosystems.However,information about the characteristics of epiphytic zooplankton community structure resulted from traditional methods is limited and hindered by the large amount of detritus and sludge attached to the macrophytes.We investigated the epiphytic zooplankton communities associated with macrophytes(Vallisneria,Nymphaea,and Thalia dealbata)in a subtropical wetland using as DNA markers of the 18 S rRNA gene and the mitochondrial cytochrome c oxidase subunit I(COI)gene.A total of 241 OTUs of zooplankton were obtained from COI amplicons,including 194 OTUs of Rotifera,22 of Cladocera,and 25 of Copepoda,while only 62 OTUs of zooplankton were obtained from 18 S rDNA amplicons including 34 OTUs of Rotifera and 28 of Copepoda.The zooplankton communities associated with the three macrophytes were similar,but they differed significantly from those in the open waters.However,there were no significant temporal differences among the zooplankton communities.Epiphytic zooplankton communities were dominated by littoral zooplankton such as Testudinella,Lecane,and Philodina.Microzooplankton,especially littoral species,utilize macrophytes as food sources and as refuges against predation.This further led to an increase inαandβdiversity of zooplankton communities in urban wetlands.Our result suggests that the joint use of multiple molecular markers could improve the taxonomic resolution and generate a comprehensive biodiversity profile of zooplankton. 展开更多
关键词 environmental DNA metabarcoding DIVERSITY MACROPHYTE cytochrome c oxidase subunit I(COI) 18 S rRNA
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Effects of Dietary Changes on the Gut Microbiota of Cynops orientalis
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作者 Yuting WANG Yuning XIE +12 位作者 Siyu WU Wenwen ZHANG Xiner CHENG Zixuan LI Fangfei HAN Jiayi SHI Yingying SHI Zhirong HE Chunna ZHANG Yixin JIANG Na ZHAO Jiaqi LI Supen WANG 《Asian Herpetological Research》 SCIE CSCD 2024年第2期63-72,共10页
The gut microbiota plays a pivotal role in the maintenance of health for amphibians,and it has been fully recognized,but the effectiveness of various influencing factors has not yet been fully clarified.Although this ... The gut microbiota plays a pivotal role in the maintenance of health for amphibians,and it has been fully recognized,but the effectiveness of various influencing factors has not yet been fully clarified.Although this association should be considered while the amphibian order Caudata is facing a severe situation of population decline and extinction,there is little understanding of the association between diets and the diversity of gut microbiota in the amphibian order Caudata.Here,we conducted an extensive analysis of the gut microbiota of Cynops orientalis fed different diets using functional prediction and 16S rRNA amplicon sequencing techniques.First,we found that wild individuals had greater gut microbial diversity and richness in comparison to captive individuals.Second,we identified the bacterial taxa associated with diets and observed differences in the relative abundance of gut microbiota among people on various diets.Finally,we have a predictive comprehension of the selection and adaptative significance of shared core ASVs in the gut microbiota in maintaining the healthy survival of C.orientalis in a large-scale spatiotemporal map.Our study emphasizes how diets alter the gut microbiota of Caudata and offers fresh perspectives on the conservation and captive management of species in Caudata. 展开更多
关键词 16S rRNA CAUDATA core microbiota DIET gut microbiota
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Impacts of Comorbidity and Mental Shock on Organic Micropollutants in Surface Water During and After the First Wave of COVID-19 Pandemic in Wuhan (2019–2021), China
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作者 Jian Zhao Jin Kang +10 位作者 Xiaofeng Cao Rui Bian Gang Liu Shengchao Hu Xinghua Wu Chong Li Dianchang Wang Weixiao Qi Cunrui Huang Huijuan Liu Jiuhui Qu 《Engineering》 SCIE EI CAS CSCD 2024年第6期40-48,共9页
The first pandemic wave of coronavirus disease 2019(COVID-19)induced a considerable increase in several antivirals and antibiotics in surface water.The common symptoms of COVID-19 are viral and bacterial infections,wh... The first pandemic wave of coronavirus disease 2019(COVID-19)induced a considerable increase in several antivirals and antibiotics in surface water.The common symptoms of COVID-19 are viral and bacterial infections,while comorbidities(e.g.,hypertension and diabetes)and mental shock(e.g.,insomnia and anxiety)are nonnegligible.Nevertheless,little is known about the long-term impacts of comorbidities and mental shock on organic micropollutants(OMPs)in surface waters.Herein,we monitored 114 OMPs in surface water and wastewater treatment plants(WWTPs)in Wuhan,China,between 2019 and 2021.The pandemic-induced OMP pollution in surface water was confirmed by significant increases in 26 OMP concentrations.Significant increases in four antihypertensives and one diabetic drug suggest that the treatment of comorbidities may induce OMP pollution.Notably,cotinine(a metabolite of nicotine)increased 155 times to 187 ngL1,which might be associated with increased smoking.Additionally,the increases in zolpidem and sulpiride might be the result of worsened insomnia and depression.Hence,it is reasonable to note that mental-health protecting drugs/behavior also contributed to OMP pollution.Among the observed OMPs,telmisartan,lopinavir,and ritonavir were associated with significantly higher ecological risks because of their limited WWTP-removal rate and high ecotoxicity.This study provides new insights into the effects of comorbidities and mental shock on OMPs in surface water during a pandemic and highlights the need to monitor the fate of related pharmaceuticals in the aquatic environment and to improve their removal efficiencies in WWTPs。 展开更多
关键词 Coronavirus disease 2019 COMORBIDITIES Mental shock MICROPOLLUTANT Surface water
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Application of hydrochemistry and strontium isotope for understanding the hydrochemical characteristics and genesis of strontium-rich groundwater in karst area,Gongcheng County,Southwest China
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作者 Mi Tang Jun Lv +3 位作者 Shi Yu Yan Liu Shao-hong You Ping-ping Jiang 《Journal of Groundwater Science and Engineering》 2024年第3期264-280,共17页
Understanding the hydrochemical characteristics and genesis mechanisms of strontium-rich groundwater is pivotal for supporting the exploitation and utilization of natural strontium-rich groundwater.In this research,27... Understanding the hydrochemical characteristics and genesis mechanisms of strontium-rich groundwater is pivotal for supporting the exploitation and utilization of natural strontium-rich groundwater.In this research,27 groundwater samples were collected.By analyzing major ion chemistry and strontium isotope data,and considering the hydrogeological context,various analytical approaches,including multivariate statistics,ion ratios,and isotopes,were used to reveal the characteristics and genesis mechanisms of strontium-rich groundwater in the study area.The findings indicate that the predominant hydrochemical type of groundwater is HCO_(3)-Ca,with Ca^(2+)and HCO_(3)^(-)as the primary cations and anions.The hydrochemistry of the strontium-rich groundwater is predominantly influenced by rock weathering processes.A combination of factors,including ion exchange,and anthropogenic activities,shapes the compositional characteristics of the groundwater in the region.The dissolution of calcite due to weathering emerges as the principal source of strontium in the groundwater.While ion exchange processes are not conducive to strontium enrichment in groundwater,their effect is relatively limited.The impact of human activities on the groundwater is minor. 展开更多
关键词 Hydrochemistry analysis STRONTIUM ^(87)Sr/^(86)Sr GROUNDWATER Karst
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First flush of storm runoff pollution from an urban catchment in China 被引量:52
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作者 LI Li-qing YIN Cheng-qing +1 位作者 HE Qing-ci KONG Ling-li 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第3期295-299,共5页
Storm runoff pollution process was investigated in an urban catchment with an area of 1.3 km^2 in Wuhan City of China. The results indicate that the pollutant concentration peaks preceded the flow peaks in all of 8 mo... Storm runoff pollution process was investigated in an urban catchment with an area of 1.3 km^2 in Wuhan City of China. The results indicate that the pollutant concentration peaks preceded the flow peaks in all of 8 monitored storm events. The intervals between pollution peak and flow peak were shorter in the rain events with higher intensity in the initial period than those with lower intensity. The fractions of pollution load transported by the first 30% of runoff volume (FF30) were 52.2%-72.1% for total suspended solids (TSS), 53.0%-65.3% for chemical oxygen demand (COD), 40.4%-50.6% for total nitrogen (TN), and 45.8%-63.2% for total phosphorus (TP), respectively. Runoff pollution was positively related to non-raining days before the rainfall. Intercepting the first 30% of runoff volume can remove 62.4% of TSS load, 59.4% of COD load, 46.8% of TN load, and 54.1% of TP load, respectively, according to all the storm events. It is suggested that controlling the first flush is a critical measure in reduction of urban stormwater pollution. 展开更多
关键词 first flush stormwater pollution urban area rainfall pattem RUNOFF
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Preparation, characterization and photocatalytic activities of boron- and cerium-codoped TiO_2 被引量:23
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作者 WEI Chao-hai TANG Xin-hu +1 位作者 LIANG Jie-rong TAN Shu-ying 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第1期90-96,共7页
Boron- and cerium-codoped TiO2 photocatalysts were synthesized using modified sol-gel reaction process and characterized by X- ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), particle size distribut... Boron- and cerium-codoped TiO2 photocatalysts were synthesized using modified sol-gel reaction process and characterized by X- ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), particle size distribution (PSD), diffuse reflectance spectra (DRS), and Brunauer-Emmett-Teller (BET). The photocatalytic activities were evaluated by monitoring the degradation of dye Acid Red B (ARB). The results showed that the prepared photocatalysts were mixed oxides mainly consisting of titania, ceria, and boron oxide. The structure of TiO2 could be transformed from amorphous to anatase and then to rutile by increasing calcination temperature; the transformation being accompanied by the growth of particle size without any obvious change in phase structure of CeO2. The XPS of B1.6Ce1.0-TiO2 prepared at 500℃ showed that a few boron atoms were incorporated into titania and ceria lattice, whereas others existed as B2O3. Cerium ions existed in two states, Ce^3+ and Ce^4+, and the atomic ratio of Ce^3+/Ce^4+ was 1.86. When boron and cerium were doped, the UV-Vis adsorption band wavelength showed an obvious shift toward the visible range (〈526 nm). As the atomic ratio of Ce/Ti increased to 1.0, the absorbance edge wavelength increased to 481 nm. The absorbance edge wavelength decreased for higher cerium doping levels (Ce/Ti=2.0). The particles size ranged from 122 to 255 nm with a domain at 168 nm (39.4%). The degradation of ARB dye indicated that the photocatalytic activities of boron- and cerium-codoped TiO2 were much higher than those of P25 (a standard TiO2 powder). The activities increased as the boron doping increased, whereas decreased when the Ce/Ti atomic ratio was greater than 0.5. The optimum atomic ratio of B/Ti and Ce/Ti was 1.6 and 0.5, respectively. 展开更多
关键词 TITANIA CERIA boron oxide photocatalytic activity Acid Red B
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Evaluation of the International Vehicle Emission (IVE) model with on-road remote sensing measurements 被引量:24
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作者 GUO Hui ZHANG Qing-yu +1 位作者 SHI Yao WANG Da-hui 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第7期818-826,共9页
Intemational Vehicle Emissions (IVE) model funded by U.S. Environmental Protection Agency (USEPA) is designed to estimate emissions from motor vehicles in developing countries. In this study, the IVE model was eva... Intemational Vehicle Emissions (IVE) model funded by U.S. Environmental Protection Agency (USEPA) is designed to estimate emissions from motor vehicles in developing countries. In this study, the IVE model was evaluated by utilizing a dataset available from the remote sensing measurements on a large number of vehicles at five different sites in Hangzhou, China, in 2004 and 2005. Average fuel-based emission factors derived from the remote sensing measurements were compared with corresponding emission factors derived from IVE calculations for urban, hot stabilized condition. The results show a good agreement between the two methods for gasoline passenger cars' HC emission for all 1VE subsectors and technology classes. In the case of CO emissions, the modeled results were reasonably good, although systematically underestimate the emissions by almost 12%-50% for different technology classes. However, the model totally overestimated NOx emissions. The IVE NOx emission factors were 1.5-3.5 times of the remote sensing measured ones. The IVE model was also evaluated for light duty gasoline truck, heavy duty gasoline vehicles and motor cycles. A notable result was observed that the decrease in emissions from technology class State II to State I were overestimated by the IVE model compared to remote sensing measurements for all the three pollutants. Finally, in order to improve emission estimation, the adjusted base emission factors from local studies are strongly recommended to be used in the IVE model. 展开更多
关键词 remote sensing IVE model fuel-based emission factor EVALUATION
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Cadmium in agricultural soils,vegetables and rice and potential health risk in vicinity of Dabaoshan Mine in Shaoguan,China 被引量:15
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作者 王振兴 胡习邦 +4 位作者 许振成 蔡立梅 王俊能 曾东 洪鸿加 《Journal of Central South University》 SCIE EI CAS 2014年第5期2004-2010,共7页
Soil cadmium(Cd)contamination resulted from mining and smelting is a major environmental concern,and health risk associated with Cd exposure to multi-media through muti-pathway is increasing.Cd concentrations in soils... Soil cadmium(Cd)contamination resulted from mining and smelting is a major environmental concern,and health risk associated with Cd exposure to multi-media through muti-pathway is increasing.Cd concentrations in soils,vegetables and paddy rice were investigated,and potential non-carcinogenic and carcinogenic health risks exposure to Cd were estimated at six villages around the Dabaoshan Mine,South China.A total of 87 soil samples were found to exceed the China's maximum permission level(MPL)for Cd,while the highest value of 4.42 mg/kg was found near irrigation ditch associated with Hengshi River in Xinyi(XY)Village.Cd contents in vegetables and rice exceeded the maximum permissible concentration by more than five times in every village.Cadmium accumulation in plants is in the order of celery>lactuca sativa L>Chinese cabbage>Romaine lettuce>asparagus lettuce>mustard>cabbage mustard>cabbage.The mean hazard quotient(HQ)of all villages is in the range of [5.29,25.75],and the mean values of cancer risk for investigated areas are more than 10 times greater than the USEPA(2009)threshold limit value of 10-4.Moreover,human non-carcinogenic and carcinogenic risks are mainly attributable to paddy rice intake,followed by vegetables intake,soil ingestion,inhalation,and dermal contact.The results indicate that Cd has a huge potential risk on human health for the local residents. 展开更多
关键词 CADMIUM health risk soil pollution VEGETABLES paddy rice dietary intake
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