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排序方式: 共有132条查询结果,搜索用时 15 毫秒
1.
In this study, we investigated the effects of cadmium chloride (CdCl2), mercury chloride (HgCl2), methylmercury chloride (CH3HgCl), and PCBs on lymphocyte proliferation in phocids. PBMCs isolated from harbour and grey seals were exposed in vitro to varying concentrations of contaminants. A reduction of viability occurred when cells were exposed to 10−4 M HgCl2 or CH3HgCl or to 50 ppm of Aroclor 1254. In both grey and harbour seals, T-lymphocyte proliferation was suppressed when their cells were incubated with 5 × 10−5 M CdCl2 or 10−4 M HgCl2. An inhibition of proliferation occurred with CH3HgCl from 10−6 M in grey seals and from 10−5 M in harbour seals. In grey seals, Aroclor 1254 reduced lymphocyte proliferation at 15 ppm. In both harbour and grey seals, CH3HgCl was ten times more immunotoxic that HgCl2. From IC50, chemicals were ranked in terms of toxicity as followed: CH3HgCl > CdCl2 > HgCl2 > Aroclor 1254. 相似文献
2.
海南岛博鳌港沉积物的沿岸输送 总被引:19,自引:0,他引:19
分析了博港沿岸沉积牧粒度参数的沿岸变化,并应用沉积物粒径趋势分析模型(GSTA模型)对沉积物运动趋势进行了分析。GSTA模型结果表明,博鳌港沿岸的泥沙在横向上表现为:万泉河口以北岸段为由海向岸运动,近期处于淤积状态;万泉河口以南岸段即玉带滩大致以NNE走向到NE走向的转折点为界,北部主要是由岸向海运动,是侵蚀岸段,而南部则主要为由海向岸运动,有少量的淤积,博鳌港沿岸泥沙输送在纵向上表现为:万泉河口以北由南向北运动,万泉河口以南,北部是由北向南运动,南部是由南向北运动,其次还运用了经验公式对GSTA结果进行了验证,得到了通过万泉河口南部(玉带滩)3个断面的沿岸漂沙量,其沿岸漂沙方向主要为南北向,以上两种分析方法得出的结果和当地的许多地貌证据基本符合,而GSTA模型在玉带滩北部泥沙纵向输运方向与经验公式计算结果所表现出的一些差异,主要是由于研究时间尺度和所用的资料特征的差异性造成的。 相似文献
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Long-term effects of a toxic algal bloom on subtidal soft-sediment macroinvertebrate communities in Wellington Harbour, New Zealand 总被引:2,自引:1,他引:2
Kerstin Krger Jonathan P.A. Gardner Ashley A. Rowden Robert G. Wear 《Estuarine, Coastal and Shelf Science》2006,67(4):589-604
The long-term effects (>1 year) of a naturally occurring toxic plankton bloom (Karenia brevisulcata) on subtidal benthic macroinvertebrate communities were investigated in Wellington Harbour, a semi-enclosed temperate embayment in New Zealand. For 3 years communities were sampled at three different sites in the harbour. Analyses revealed that community recovery following the bloom was site-specific. Multivariate analyses indicated that at one site community composition was approaching recovery 3 years post-bloom. At the second site, a sequential recovery process was indicated, whereas at the third site the community composition oscillated from year to year, but did not show any signs of a sequential recovery process. The nature of the hydrodynamic regime was identified as a major factor influencing the observed recovery processes. Communities exposed to an active hydrodynamic regime were less affected by the bloom and differed little in their composition pre- and post-bloom, as they were naturally in a perpetual state of recovery as indicated by a dominance of r-selected species. The community at the hydrodynamically less active site was more affected by the bloom and exhibited temporal differences in composition consistent with successional models. Complete recovery to a pre-disturbance climax community dominated by K-selected species is likely to take 4–5 years, if not interrupted by other disturbances. Given the increased occurrence of harmful algal blooms worldwide, more monitoring and manipulative studies are needed to further evaluate the effects of such disturbances on macrobenthic communities. 相似文献
5.
厦门港岩相潮间带多毛类的生态 总被引:2,自引:0,他引:2
本文根据1987年2、5、8、11月调查资料,研究了厦门港岩相潮间带多毛类的种类组成、种类与数量的垂直分布、季节变化,并与大亚湾多毛类生态进行比较。结果表明,调查区域有多毛类47种。平均栖息密度60个/m^2,平均生物量1.78g/m^2,潮汐作用影响多毛类的种数、密度、生物量的垂直分布。多毛类数量的季节变化不甚明显,但冬季的栖息密度和春季的生物量较高。 相似文献
6.
本文查阅了从1973-1985,13年的历史资料,对石臼港沿岸波浪场进行了详细的分类、统计分析和计算,提出了各类较强天气系统影响石(即指石臼港)的极端区域,同时获得了石港沿岸各类天气系统影响下的波浪分布特点以及波高计算式,为保障石港的生产及港口建设为石港的波了提供了有益的分析数据和预报手段。 相似文献
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厦门港潮汐水流及浑水悬沙整体物理模型于1989年建成后,已进行了不少有意义的试验研究工作,取得较好效果。本文主要介绍模型的设计思想、相似准则、浑水悬沙相似理论的探讨、模型设计方法以及模型沙的选择等。 相似文献
9.
In this paper a novel series of field measurements are presented, which are the first to elucidate the processes influencing siltation in Botlek Harbour. Botlek Harbour is situated at the limit of saline water intrusion in the Rotterdam Waterway. Normally, after the ebb tide fresher river waters are found in the Rotterdam Waterway at the location of Botlek Harbour. On the flooding tide, the tip of the salt wedge is advected along the Rotterdam Waterway towards the mouth of Botlek Harbour. Hence on flood, a lock-exchange mechanism operates between Botlek Harbour and the Rotterdam Waterway. On the flood tide, when there is a supply of suspended particulate matter (SPM) associated with the presence of the estuarine turbidity maximum (ETM) at the mouth of the harbour, the survey data show exchange of SPM into the harbour. This lock-exchange process is found to be the dominant cause for SPM transport into the harbour. This is further substantiated by an analysis of the mass transport mechanisms. In this analysis, the vertical profiles of the instantaneous velocity, salinity and SPM concentration fields, recorded during the surveys, were decomposed into advective and dispersive transport components. The results of this analysis indicate that the correlation between the lock-exchange mechanism on the flood tide with the availability of SPM for exchange and efficient trapping, dominate the total exchange of SPM (97%). Hence, the increase in measured near-bed SPM concentration within the harbour is ascribed to tidal advection of saline water and the ETM along the Rotterdam Waterway. Tidal advection controls the density difference between the estuary and harbour, as well as the availability of SPM for exchange at the entrance to Botlek Harbour. The location of the ETM at the tip of the salt wedge is a key factor in supplying SPM to Botlek Harbour. Consequently the timing of the availability of SPM at the mouth of the harbour needs to be considered in siltation studies. The survey data suggest that Botlek Harbour basin has a 100% trapping efficiency. Analysis of 5 months of data, from a measuring rig located within the harbour, show excursions of the limit of the salt wedge and ETM. These excursions are likely to affect siltation of upstream harbours. Salinity-induced density gradients control the transport and subsequent trapping of SPM in the estuary in close proximity to the harbour entrance, the exchange of SPM between the estuary and harbour, and the trapping of SPM in the harbour basin. 相似文献
10.
厦门西港浮游动物生态研究 总被引:5,自引:1,他引:4
本文根据1994年7月和12月于厦门西港所获得的调查资料,分析了浮游动物的丰度及其季节和年际变化,讨论了浮游动物的物种和生态类群多样性,结果表明,7月浮游动物湿重生物量月均值约为12月的2.56倍,与历史资料相比,呈逐年趋势;7月和12月在西港共记录浮游动物55种和多种浮游幼体,它们分别隶属于5个生态类群,文中还分析了潮汐地浮游动物分布的影响。 相似文献