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Augmentation of PM_(1.0) measurements based on machine learning model and environmental factors
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作者 Hyemin Hwang Chang Hyeok Kim +3 位作者 Jong-Sung Park Sechan Park Jong Bum Kim Jae Young Lee 《Journal of Environmental Sciences》 2025年第10期91-101,共11页
PM_(1.0),particulate matter with an aerodynamic diameter smaller than 1.0μm,can adversely affect human health.However,fewer stations are capable of measuring PM_(1.0) concentrations than PM2.5 and PM10 concentrations... PM_(1.0),particulate matter with an aerodynamic diameter smaller than 1.0μm,can adversely affect human health.However,fewer stations are capable of measuring PM_(1.0) concentrations than PM2.5 and PM10 concentrations in real time(i.e.,only 9 locations for PM_(1.0) vs.623 locations for PM2.5 or PM10)in South Korea,making it impossible to conduct a nationwide health risk analysis of PM_(1.0).Thus,this study aimed to develop a PM_(1.0) prediction model using a random forest algorithm based on PM_(1.0) data from the nine measurement stations and various environmental input factors.Cross validation,in which the model was trained in eight stations and tested in the remaining station,achieved an average R^(2) of 0.913.The high R^(2) value achieved undermutually exclusive training and test locations in the cross validation can be ascribed to the fact that all the locations had similar relationships between PM_(1.0) and the input factors,which were captured by our model.Moreover,results of feature importance analysis showed that PM2.5 and PM10 concentrations were the two most important input features in predicting PM_(1.0) concentration.Finally,the model was used to estimate the PM_(1.0) concentrations in 623 locations,where input factors such as PM2.5 and PM10 can be obtained.Based on the augmented profile,we identified Seoul and Ansan to be PM_(1.0) concentration hotspots.These regions are large cities or the center of anthropogenic and industrial activities.The proposed model and the augmented PM_(1.0) profiles can be used for large epidemiological studies to understand the health impacts of PM_(1.0). 展开更多
关键词 Particulate matter Random forest Input factor PM_(1.0)prediction model Cross validation Feature importance analysis
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Effects of vegetation type on soil microbial community structure and catabolic diversity assessed by polyphasic methods in North China 被引量:63
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作者 HAN Xue-mei WANG Ren-qing +3 位作者 LIU Jian WANG Meng-cheng ZHOU Juan GUO Wei-hua 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第10期1228-1234,共7页
Soil microbes play a major role in ecological processes and are closely associated with the aboveground plant community. In order to understand the effects of vegetation type on the characteristics of soil microbial c... Soil microbes play a major role in ecological processes and are closely associated with the aboveground plant community. In order to understand the effects of vegetation type on the characteristics of soil microbial communities, the soil microbial communities were assessed by plate counts, phospholipid fatty acid (PLFA) and Biolog microplate techniques in five plant communities, i.e., soybean field (SF), artificial turf (AT), artificial shrub (AS), natural shrub (NS), and maize field (MF) in Jinan, Shandong Province, North China. The results showed that plant diversity had little discernible effect on microbial biomass but a positive impact on the evenness of utilized substrates in Biolog microplate. Legumes could significantly enhance the number of cultural microorganisms, microbial biomass, and community catabolic diversity. Except for SF dominated by legumes, the biomass of fungi and the catabolic diversity of microbial community were higher in less disturbed soil beneath NS than in frequently disturbed soils beneath the other vegetation types. These results confirmed that high number of plant species, legumes, and natural vegetation types tend to support soil microbial communities with higher function. The present study also found a significant correlation between the number of cultured bacteria and catabolic diversity of the bacterial community. Different research methods led to varied results in this study. The combination of several approaches is recommended for accurately describing the characteristics of microbial communities in many respects. 展开更多
关键词 BIOLOG LEGUME microbial biomass plant diversity phospholipid fatty acid (PLFA) soil microbes
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Genetic diversity of the endangered species Rosa rugosa Thunb.in China and implications for conservation strategies 被引量:3
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作者 Ji-Hong YANG Shu-Ping ZHANG +2 位作者 Jian LIU Wen ZHAI Ren-Qing WANG 《Journal of Systematics and Evolution》 SCIE CSCD 北大核心 2009年第6期515-524,共10页
Rosa rugosa Thunb. is one of the dominant and important shrub species in estuary dunes and shingle beaches of northern China. However, its area of distribution, the number of populations, and the size of each populati... Rosa rugosa Thunb. is one of the dominant and important shrub species in estuary dunes and shingle beaches of northern China. However, its area of distribution, the number of populations, and the size of each population have decreased rapidly in the past two decades because of habitat degradation and loss. Random amplified polymorphic DNA markers were used to determine the genetic diversity of four remaining large natural populations of R. rugosa and to discuss an effective conservation strategy for this endangered species in China. High genetic variations were detected in R. rugosa populations in China. The mean percentage of polymorphic loci (P%) within four local populations was 57.99%, with the P% of the total population being 75.30%. Mean Shannon's information index (H0) was 0.2826, whereas total Ho was 0.3513. The genetic differentiation among populations was 0.1878, which indicates that most genetic diversity occurs within populations. Population Tumenjiang (TMJ) showed the highest genetic diversity (P% = 66.27%; H0 = 0.3117) and contained two exclusive bands. Population Changshandao (CSD) showed higher genetic diversity (P% =59.04%; H0 = 0.3065). Populations TMJ and CSD contained 95.33% and 99.33%, respectively, of loci with moderate to high frequency (P〉0.05) of the total population. These results indicate that populations TMJ and CSD should be given priority for in situ conservation and regarded as seed or propagule sources for ex situ conservation. The results of the present study also suggest that R. rugosa in China has become endangered as a result of human actions rather than genetic depression of populations; thus, human interference should be absolutely forbidden in R. rugosa habitats. 展开更多
关键词 China genetic diversity in situ conservation random amplified polymorphic DNA (RAPD) Rosa rugosa.
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Evaluation of Estrogenic Activity and Measurement of EDCs in Wastewater Treatment Plants 被引量:2
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作者 B. C. Lee J. Y. Jung H. K. Kim 《Journal of Ocean University of China》 SCIE CAS 2006年第4期351-356,共6页
Correlations between estrogenic activity and DOC/UV260 ratio in wastewater treatment processes were investigated to propose a simple, reliable and comprehensive indicator for the presence of estrogenic substances. Con... Correlations between estrogenic activity and DOC/UV260 ratio in wastewater treatment processes were investigated to propose a simple, reliable and comprehensive indicator for the presence of estrogenic substances. Contrary to this, when short-term bioassays such as the E-SCREEN, receptor binding and reporter gene expression assays are used for detecting estrogenic activity in the wastewater sample, they require a long time, at least a few days. The major factors contributing to the estrogenic activity were found to be 17β-estradiol (E2) and estrone (El). A good relationship between the DOC/ UV260 ratio and the concentration of estrogens (El and E2) in the effluent of the activated sludge process was found: the E2 concentration increased as the DOC/UV260 ratio increased while the E1 concentration decreased. The relative estrogenic activity and DOC/UV260 ratio showed a good correlation (R^2 = 0.84) for all sewage samples except the ozonized samples in the sewage treatment plants. This study shows that the estrogenic compounds are hard to be mineralized by the conventional biological processes. Advanced oxidation processes are required to further remove estrogenic substances in the secondary effluent. By analysis of DOC and UV260, the estrogenic activity in the wastewater can be rapidly estimated. 展开更多
关键词 activated sludge process estrogenic substances 17Β-ESTRADIOL ESTRONE DOC/UV260
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Characterization of suspended solids and particle-bound heavy metals in a first flush of highway runoff 被引量:2
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作者 Fa-hui NIE Tian LI +2 位作者 Hai-feng YAO Man FENG Guang-kai ZHANG 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第11期1567-1575,共9页
To investigate the dynamic characteristics of total suspended solids (TSS) and their particle-bound heavy metals in a first flush, the runoff sampling together with its flow rate measuring was conducted for three rain... To investigate the dynamic characteristics of total suspended solids (TSS) and their particle-bound heavy metals in a first flush, the runoff sampling together with its flow rate measuring was conducted for three rainfall events at outfalls of highway in Shanghai from June to September 2007. Field samples were analyzed to determine the concentrations of TSS and particle-bound heavy metals, such as Zn, Pb, and Cu. Results show that the wash off behavior of TSS under varying runoff rate condition can be explained by different antecedent dry weather period (ADWP). Contribution of fine fraction (<45 μm) to TSS was generally higher than that of coarse fraction (>45 μm). When the runoff flow increased obviously, a significant contribution of the coarse fraction was observed for a certain rainfall events with long antecedent dry weather condition. The changes of total metals concentration and particle-bound metal concentrations were strongly dependent on the TSS variation. TSS was generally well correlated with most particulate-bound heavy metals. Of the heavy metals, the concentration of Zn was found considerably high and that of Pb was significantly low at North Zhongshan 2 Road, in Shanghai, China, but they are still within the range reported in the literature. Fluctuation of heavy metal contents in the coarse fraction during a first flush period was more significant compared with that in the fine fraction. The results will assist in the development of effective control strategies to minimize heavy metals and solids in highway runoff. 展开更多
关键词 Heavy metals Highway runoff First flush Suspended solids (SS)
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