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81.
Guor-Cheng Fang Chaur-Tsuen Lo Winn-Jung Huang Jyh-Cherng Chen Yuh-Shen Wu Jun-Han Huang Yi-Liang Huang 《Environmental Earth Sciences》2011,64(5):1237-1247
The main purpose of this study was to monitor ambient air particles and particulate-bound mercury Hg(p) in total suspended
particulates (TSP) concentration, dry deposition at five characteristic-sampling sites. In addition, the calculated/measured
dry deposition flux ratios of ambient air particles and particulate-bound mercury Hg(p) using three dry deposition models
during the years of 2009–2010 were also studied. The results showed that the order of seasonal variations for mean particulate-bound
mercury Hg(p) concentrations in TSP at Bei-shi (suburban/coastal), Chang-hua (downtown) and He-mei (residential) were all
shown as spring > fall, winter > summer, respectively. However, the order of seasonal variations mean particulate-bound mercury
Hg(p) concentrations in TSP that occurred at Gao-mei (wetland) were shown as spring > fall > winter > summer, respectively.
Finally, the results of this study also indicated that using the Noll and Fang model exhibited batten prediction results for
ambient air particles and particulate-bound mercury Hg(p) dry deposition when compared with the other depositions models at
any of the characteristic-sampling sites for this study. 相似文献
82.
Polycyclic aromatic hydrocarbon concentrations in urban soils representing different land use categories in Shanghai 总被引:2,自引:0,他引:2
Jing Liang Guangjun Ma Hailan Fang Ling Chen Peter Christie 《Environmental Earth Sciences》2011,62(1):33-42
An extensive soil survey was carried out in Shanghai to investigate the spatial distribution and possible sources of polycyclic
aromatic hydrocarbons (PAHs) in urban soils. Soil samples were collected from highways, iron-smelting plants, steel-smelting
plants, shipbuilding yards, coking plants, power plants, chemical plants, urban parks, university campuses and residential
areas and were analyzed for 16 PAHs by gas chromatography with mass detection. High PAH concentrations were found in all locations
investigated, with mean values of soil total PAH concentrations in the range 3,279–38,868 μg/kg DM, and the PAH concentrations
were significantly influenced by soil organic matter content. Soil PAH profiles in all districts were dominated by PAHs with
4–6 rings. Principal components analysis and diagnostic ratios of PAHs indicate that they were mainly derived from coal combustion
and petroleum but in soils from highways the PAHs were derived largely from vehicle exhaust emissions. The high concentrations
of PAHs found indicate that many urban soils in Shanghai represent a potential hazard to public health. 相似文献
83.
利用2008年夏季我国第3次北极科学考察资料,基于流式细胞技术,对白令海北部陆架区的微微型浮游植物丰度、细胞大小(碳含量)、色素浓度的分布特征进行了分析,并对该类群的环境适应性进行了研究。结果表明,微微型浮游植物中仅含聚球藻和真核藻,其丰度范围分别为0.14×106 2.69×106和0.23×106-12.49×106个/dm3。聚球藻的叶绿素a和藻红蛋白含量、微微型真核藻的叶绿素a含量与类群丰度以及微微型真核藻的类胡萝卜素含量与细胞大小间均存在同向变化趋势。两类藻偏向于喜温嗜淡型,更适合在寡营养环境中保持较高的丰度,但能在高营养盐浓度下形成相对较高的碳含量。越接近陆地,细胞越小,丰度越大,碳含量及FL2/FL3越低;所处层位越深、纬度越高,则细胞越大,碳含量及FL2/FL3越高。北极气温升高和径流量的增加有利于陆架区微微型浮游植物类群丰度的增加。 相似文献
84.
Duan Lin XiuQin LiHongDa Fang YanHong DongZhuoXuan Huang JiaHui Chen 《Estuarine, Coastal and Shelf Science》2011
To study the relationships between species distribution and environmental variables, calanoid copepods were classified and enumerated, and environmental variables were analyzed along 91 sites of the Pearl River Estuary (China) and adjacent waters. The 91 sites were divided into 3 groups based on surface salinity: the Inner area had salinity level below 10‰ and was mostly located in the Pearl River Estuary, the Coastal area had salinity between 10‰ and 32‰ and was almost located along the coastline, while the Offshore area had salinity level higher than 32‰ and was mainly located in the open area. Indicator Species Analysis was conducted to identify the indicator species within each group from among all calanoid copepods taxa. We found that the Inner area was characterized by Acartiella sinensis, Pseudodiaptomus poplesia and Pseudodiaptomus inopinus, the coastal area was characterized by Temora turbinata and Subeucalanus subcrassus, and the Offshore area was characterized by Paracandacia truncata, Subeucalanus subtenuis, Euchaeta rimana, Pareucalanus attenuatus, Rhincalanus cornutus, Cosmocalanus darwini, Centropages gracilis, Undinula vulgaris, Nannocalanus minor and Paraeuchaeta russelli. Canonical Correspondence Analysis (CCA) was used to identify relevant biotic and abiotic parameters that can best explain the distribution of calanoid copepods. CCA showed that during the summer of 2006, salinity, nutrient variables, especially SiO3–Si, NO3–N and DTN, Depth and Chl a were the environmental variables that strongly impacted the distribution and community structure of calanoid copepods. 相似文献
85.
文中主要以SZC16-1型XBT测量电路为例,从固有可靠性预计的理论基础出发,通过对基本元器件、单元电路及整个可靠度的计算,给出了目前该型号XBT测量电路的可靠性参数,同时阐述了硬件电路可靠性研究的方法和步骤. 相似文献
86.
87.
栖霞牙山地区地处华北地台东部,对该区的似斑状花岗闪长岩体所作的岩石地球化学研究表明,该区岩石为钙碱性偏铝质岩石;微量元素MORB标准化蛛网图显示富集大离子亲石元素Ba、Sr,亏损高场强元素Nb、Ta、Hf、Y;K/Rb比值为295.34~388.88,Rb/Sr比值为0.21~0.29;稀土元素蛛网图表现为较平滑的具微弱负Eu异常向右陡倾的稀土元素配分模式曲线,∑LREE/∑HREE为9.14~12.22,显示轻重稀土元素分异较好。结合构造背景分析,认为牙山花岗闪长岩体为早白垩世太平洋板块向欧亚板块俯冲诱发的地幔柱活动,造成地幔底辟,引起地壳部分熔融,形成壳幔混合岩浆并进一步侵入形成。 相似文献
88.
Seven compounds (1–7) were identified from the cultivation of the endophytic fungus Exophiala oligosperma (EN-21) that was isolated from the inner tissue of the marine red alga Laurencia similis. Their structures were identified with spectroscopic and chemical methods as 2-phenoxynaphthalene (1), (2S, 3R, 4E, 8E)-1-O-β-D-glucopyranosyl-3-hydroxy-2-[(R)-2′-hydroxyoctadecanoyl] amino-9-methyl-4, 8-octadeca-diene (2), (22E,24R)-ergosta-7,22-dien-3β,5α,6β-triol (3), (22E, 24R)-3β, 5α, 9α-trihydroxy- ergosta-7, ... 相似文献
89.
The 16S and 18S ribosomal ribonucleic acid genes of microbial organisms collected from the contrasting environments (temperature, salinity, silicate, phosphate and nitrate, p <0.05) of the inner and outer basins of Kongsfjorden (Spitsbergen, Arctic) were studied using polymerase chain reaction-denaturing gradient gel electrophoresis(DGGE) fingerprinting. Comparison of the microbial fingerprints and the physicochemical parameters revealed that molecular methodology exhibited a greater sensitivity. Sequences obtained from bacterial DGGE were affiliated with four main phylogenetic groups of bacteria:Proteobacteria(Alpha, Beta and Gamma), Bacteroidetes, Verrucomicrobia and Cyanobacteria. The relationships between the genotype distribution of these microbes and associated biotic/abiotic factors, revealed by canonical correspondence analysis, showed that Station 1 at 30 m (outer fjord) was grouped separately from the other sites. This difference could be a consequence of the thermocline and base of the euphotic layer at this depth where the Atlantic and Arctic-type waters overlapped. 相似文献
90.
A 1.5-layer reduced-gravity model forced by wind stress is used to study the bifurcations of the North Equatorial Current(NEC).The authors found that after removing the Ekman drift,the modelled circulations can serve well as a proxy of the SODA circulations on the σθ=25.0 kg m~-3 potential density surface based on available long-term reanalysis wind stress data.The modelled results show that the location of the western boundary bifurcation of the NEC depends on both zonal averaged and local zero wind stress curl latitude.The effects of the anomalous wind stress curl added in different areas are also investigated and it is found that they can change the strength of the Mindanao Eddy(ME),and then influence the interior pathway. 相似文献