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Samples of green lipped mussels (Perna viridis) were collected from three sites (Huoshao, I’Maluan and Tong’an) around Xiamen coastal waters, where levels of various trace organic pollutants have been studied. Samples were also collected at a “cleaner” reference site near Dongshan Island for comparison. Clearance rate, absorption efficiency and oxygen consumption of the mussels were measured under controlled laboratory condition; organic pollutants in their tissues were also analyzed. Scope for growth (SFG) was employed as a general biomarker to evaluate the stress of pollutants. Specimens from Tong’an site had the lowest SFG values (1.14 J/h/g); while specimens from the I’Maluan site and Huoshao site had SFG values of 5.01 and 6.72 J/h/g, respectively. Specimens from Dongshan (reference site) had a relatively high SFG value of 10.96 J/h/g. There was a significant negative correlation between the SFG of the different populations of green lipped mussels and the concentration of DDT in their tissues. 相似文献
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Determination and load of organophosphorus and organochlorine pesticides at water from Jiulong River Estuary,China 总被引:15,自引:0,他引:15
Zulin Z Huasheng H Xinhong W Jianqing L Weiqi C Li X 《Marine pollution bulletin》2002,45(1-12):397-402
Seventeen organic phosphorus pesticides (OPs) and 18 organic chlorine pesticides (OCs) at water from Jiulong River Estuary (JLRE) are determined by SPE–GC–(FPD and μECD). The contents of the total OPs (17) ranged from 134.8 to 354.6 ng/l (the mean is 227.2 ng/l). Total OCs concentrations varied from 115.4 to 414.7 ng/l in water (mean 237.7 ng/l). The levels of total hexachlorocyclohexane in water varied from 31.95 to 129.8 ng/l (mean 62.51 ng/l), and those of total DDTs were in the range 19.24–96.64 ng/l (mean 48.69 ng/l). The distribution and behavior characteristics of OPs indicate that five main OPs (methamidophos, dichlorvos, malathion, omethoate and dimethoate) occupied the most part of the total OPs, in addition, the sources of the OPs (mainly from current usage) are not stable. While the OCs mainly came from early application and were more stable. The OPs did not have obvious correlation with the dissoved organic carbon and suspended particulate matter at water from JLRE. It maybe due to the complicated hydrological kinetics in the estuary, and the higher water solubility and weak absorption (with organic matter) action of OPs. When compared with other areas, the OPs and OCs level in JLRE are some moderate. 相似文献
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苏联粮食产量预报方法的初步研究 总被引:1,自引:0,他引:1
苏联粮食产量有准2年和4年振荡周期,它与准2年赤道平流层位相风有较好的对应关系,吹西风往往歉收;吹东风则经常丰收.并与南方涛动有4年左右同相振荡关系,涛动由高指数变化为低指数时,粮食大多为歉收;反之多为丰收.4—6月份500hPa环流形势,西欧有阻高建立且稳定,并在欧洲盛行“N”型环流形势时,则有利于粮食丰收;反之则歉收. 相似文献
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为了解和探讨3~5环PAHs对海水鱼类胚胎发育的毒性及作用方式,比较研究了菲(phenanthrene,Phe)、芘(pyrene,Py)、苯并(a)芘(benzo(a)pyrene,BaP)单一暴露和三者各自与α-萘黄酮(α-naphthoflavone,ANF)联合暴露对海水青鳉(marine medaka, Oryzias melastigma)胚胎发育的毒性效应。胚胎体内EROD活性、发育畸形、孵化率和心律等毒性指标被测定,结果显示:Phe,Py和BaP对海水青鳉胚胎体内EROD活性的诱导能力大小为BaP>Py>Phe,各化合物对EROD诱导与发育畸形之间的关系较为复杂,除Phe所引起的EROD诱导与畸形指数之间呈显著相关(r=0.95,p=0.015)外,Py和BaP均无相关性;在100 μg/dm3 ANF影响下,CYP1A活性诱导被抑制,但胚胎发育的畸形指数被显著提高,ANF分别与Phe,Py和BaP的联合暴露对胚胎发育呈潜在的协同作用。本文研究初步表明,3~5环PAHs化合物对海水青鳉胚胎发育的毒性作用方式可能不同;CYP1A活性抑制在PAHs混合物对海水青鳉胚胎发育的毒性作用过程中未起到缓解毒性的作用,CYP1A抑制剂与PAH型CYP1A诱导剂的混合物对鱼类胚胎发育具有潜在的协同毒性作用,现有的PAHs混合物毒性风险评价方法可能低估了实际环境中PAHs的风险;海水青鳉早期生活阶段的心脏发育对PAHs混合物暴露较为敏感,可推荐其作为生物标志物指示PAHs或溢油污染。 相似文献
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大气细颗粒物(PM2.5)质量浓度是重要的空气质量指标之一。为了促进区域PM2.5浓度监测的研究,同时拓展利用CE318太阳光度计等光学传感器反演的大气气溶胶产品的应用领域,本文首先基于北京地区2014年—2017年大气气溶胶反演的粒径尺度谱分布产品,计算表征PM2.5的粒子体积,并结合同一时间北京地区35个空气质量站点提供的PM2.5质量浓度参考值计算转换系数,对样本区间进行划分以构建转换模型。其次,利用各CE318站点数据所得转换系数及其相对精度,对研究区PM2.5质量浓度估算误差空间分布,以及转换系数偏差对估值误差贡献情况进行评价。研究结果表明,由CE318站PM2.5粒子体积与其临近空气质量站PM2.5质量浓度联合建立的转换系数是一种与气溶胶理化属性密切相关的参数指标,可将时间和空间维度上PM2.5体积与PM2.5质量浓度之间的关系映射到由理化属性主导的维度上,可用于对估值模型进行细化和分类,构建分段转换函数模型,使得各分段区间内具有较高的模型拟合精度。基于转换系数的北京地区PM2.5浓度估值的相对误差多年均值介于12.8 %—28.7 %,而转换系数相对偏差对PM2.5质量浓度估值相对误差的影响显著,二者之间具有“r”型结构。当转换系数相对偏差介于-16.3 %至24.5 %时,该偏差的出现概率约为66.5 %,使得PM2.5质量浓度估值误差在20 %以内,表明采用此种方法对相应站点的PM2.5质量浓度进行估值具有相当的精度和稳定性。以上研究结果可为地面观测站稀少区域利用卫星光学遥感开展空气质量大范围监测应用提供理论前提和技术支持。 相似文献
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Jianyu Hu Hiroshi Kawamura Chunyan Li Huasheng Hong Yuwu Jiang 《Journal of Oceanography》2010,66(5):591-610
Patterns and features of currents and seawater volume transports in the Taiwan Strait have been reviewed by examining the results from more than 150 research papers in recent decades. It is noted that there are diverse or even conflicting viewpoints on these subjects. Here both common and different opinions are summarized. This review paper covers the studies involving in situ measurements and numerical modeling of current velocity, analyses of hydrographic data, and classification of water masses. Generally speaking, there are three currents in the Taiwan Strait: the China Coastal Current along the Fujian coast in the western Taiwan Strait, the extension of the South China Sea Warm Current in the western and central Taiwan Strait, and the Kuroshio’s branch or loop current intruding through the eastern Taiwan Strait. The current pattern in winter is quite different from that in summer, and the currents also exhibit differences between the upper and lower layers. The seawater volume transport through the Taiwan Strait is about 2.3 Sv northward in summer but about 0.8 Sv northward in winter. Both the current pattern and the seawater transport vary with local winds in the Taiwan Strait. This is particularly true in winter when the currents and the transport in the upper layer are significantly affected by strong northeasterly winds. 相似文献