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1.
利用从珠江莲花山河段采集的淡水和有大洋海过滤后，按不同盐度混后，模拟河口咸淡水交汇区重金属在水中各微粒级的分配特征，实验结果表明，在各种盐度条件下，Ｆｅ，Ａｌ，Ｃｕ，Ｐｂ，Ｚｎ和Ｃｄ主要以粒径＞１．０μｍ和＜０．２２μｍ的微粒存在于水中，在加入Ｆｅ＾３＋，Ａｌ＾３＋模拟实验中，重金属绝大部分含量形成粒径＞１．０μｍ的微粒，其中Ｆｅ达９９％以上，Ｃｕ，Ｐｂ，约９５％，Ａｌ约有７０％－９０％，Ｃｄ约４ 相似文献
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金属离子对牙鲆仔鱼的毒性影响 总被引：4，自引：0，他引：4
本文用静水生物实验法进行了Ｚｎ、Ｃｕ、Ｐｂ、Ｃｄ金属离子对海洋底栖鱼类牙鲆（Ｐａｒａｌｉｃｈｔｈｙｓｏｌｉｖａｃｅｕｓ）仔鱼的成活影响研究。结果表明：Ｃｕ（２＋）、Ｃｄ（２＋）、Ｚｎ（２＋）、Ｐｂ（２＋）对牙鲆仔鱼２４ｈＬＣ（５０）分别为１．１４、１．５１、４．６８、５．８９ｍｇ／ｄｍ３．４８ｈＬＣ（５０）分别为０．１４、０．８３、０．９９、３．４７ｍｇ／ｄｍ３．７２ｈＬＣ（５０）分别为０．０６、０．３６、０．７１、０．９３ｍｇ／ｄｍ３．９６ｈＬＣ（５０）分别为０．０２、０．１４、０．４３、０．５３ｍｇ／ｄｍ３．Ｃｕ（２＋）对牙鲆仔鱼的毒性最大，Ｐｂ（２＋）的毒性最小．４种金属离子对仔鱼的毒性顺序依次为：Ｃｕ（２＋）＞Ｃｄ（２＋）＞Ｚｎ（２＋）＞Ｐｂ（２＋）． 相似文献
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珠江口水域微表层中的痕量金属 总被引：2，自引：0，他引：2
采用自制滚筒式自动采样器采样，研究了珠江口水域微表层中Ｆｅ，Ｍｎ，Ｃｕ，Ｐｂ，Ｚｎ，Ｃｄ的含量，分布变化及富集状况。并通过颗粒痕量金属／颗粒Ｆｅ比值计算，探讨了痕量金属的来源。结果表明：Ｃｕ，Ｐｂ，Ｚｎ，Ｃｄ在微表层平均富集系数分别为２．３，１．４，３．０和１．９颗粒态Ｆｅ，Ｍｎ的平均富集系数为１．１和０．９。各种金属有明显的季节和空间变化，有各种不同的来源。 相似文献
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江阴岛海域溶解态Cu,Pb,Cd的含量及其与营养盐的关系 总被引：2，自引：0，他引：2
首次报道了福建省福清市江阴岛海域溶解态Ｃｕ，Ｐｂ，Ｃｄ的含量，并探讨了它们与营养盐的关系。１９９０年５月溶解态Ｃｕ，Ｐｂ，Ｃｄ的平均含量分别为０．８２、０．３８０、０．０２２μｇ／ｄｍ＾２，１０月的平均含量分别为０．７６、０．３８２、０．０３２μｇ／ｄｍ＾２。其５月溶解态Ｃｕ与无机氮Ｎ，硅酸盐间的线性回归相关式分别为Ｃｕ、（μｇ／ｄｍ＾３）＝０．４３８＋０．０３７７Ｎ（μｇ／ｄｍ＾３）、Ｃｕ（μｇ 相似文献
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金属离子对长毛对虾酸性磷酸酶的影响 总被引：8，自引：0，他引：8
本文研究几种金属离子分别对健康虾和病虾酸性磷酸酶ＡＣＰａｓｅ（ＥＣ３．１．３．２）活性的影响。结果表明,Ｎｉ＾２＋、Ｍｇ＾２＋、Ｃｄ＾２＋对酶无明显抑制作用,Ｚｎ＾２＋、Ｃｕ＾２＋、Ｈｇ＾２＋对酶活力抑制明显。当Ｈｇ＾２＋离子浓度达０．５ｍｍｏｌ／ｄｍ＾２时,酶活力被抑制９６％和９５％;各金属离子对酶的抑制强度依次为Ｈｇ＾２＋〉Ｃｕ＾２＋〉Ｚｎ＾２＋〉Ｐｂ＾２＋〉Ｃｄ＾２＋、Ｍｇ＾２＋〉Ｎｉ＾２＋ 相似文献
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台湾海峡西部海域大气中金属的特征 总被引：9，自引：2，他引：7
１９９１－１９９３年,收集了台湾海峡西部海域上空大气中的１８１个颗粒样品和２个颗粒分级样品。采用原子分光光度法分析了其中的颗粒金属Ａｌ、Ｆｅ、Ｃｕ、ｐｂ、Ｃｄ,Ｎａ,台湾海峡西部海域大气中颗粒金属Ｆｅ、Ｃｕ、ｐｂ、Ｃｄ的含量明显低于大陆城市大气中的含量,大气颗粒物中Ａｌ、Ｃｕ,Ｐｂ显示了明显的年变化,Ａｌ、Ｆｅ、Ｃｕ、Ｐｂ、Ｃｄ表现出明显的季节变化,干季大于湿季,影响大气颗粒金属元素浓度季节变化的 相似文献
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海水pH对疏浚物中重金属释放的影响 总被引：2，自引：0，他引：2
对厦门员当湖污染疏浚物中的Ｃｄ，Ｃｕ和Ｐｂ在不同ｐＨ的天然海水中溶出的模拟研究结果表明：在ｐＨ为５．０，６．５，８．３条件下，疏浚物中的Ｃｄ，Ｃｕ，Ｐｂ的释放率分别为８０％－９４％，４％－９％和１．０％－２．２％；在相同条件下，Ｃｄ，Ｃｕ，Ｐｂ的释放量（释放量）均随ｐＨ值增大而减少，释放量的顺序为Ｃｄ＞Ｃｕ＞Ｐｂ。讨论了ｐＨ对释放作用的影响及释放过程所遵循的动力学规律。 相似文献
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铜对鲫鱼血清生化成分的影响 总被引：12，自引：0，他引：12
本文通过分析鲫鱼血清生化成分含量的变化，研究Ｃｕ对鲫鱼的致毒效应。试验结果表明，（１）血清Ｎａ＾＋，Ｃｌ＾－含量随Ｃｕ浓度的升高而增加，在水中Ｃｕ浓度为３．９１μｍｏｌ／Ｌ时达到最大值，而血清Ｋ＾＋不受Ｃｕ影响。（２）血清胆固醇，球蛋白含量和ＧＯＴ，ＡＬＰ酶活性均在Ｃｕ浓度为０．７８μｍｏｌ／Ｌ时达到最高值，若再增加Ｃｕ浓度，血清胆固醇，球蛋白含量有所下降，但仍高于对照组，而ＧＯＴ，ＡＬＰ酶活性却 相似文献
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应用水汽化学的方法学和理论,研究南,北极雪,冰,水中的Ｚｎ＾２＋等离子,南北,极雪,冰,水中Ｚｎ＾２＋,Ｃｄ＾２＋,Ｐｂ＾２＋,Ｃｕ＾２＋,Ｓｎ＾４＋,Ｂｉ＾３＋离子含量的空间变化很小,与水汽化学原理计算的离子总平均含量Ｚｎ＾２＋,５．０μｇ／Ｌ,Ｐｂ＾２＋＋０．０３０μｇ／Ｌ,Ｃｕ＾２＋＋０．７０μｇ／Ｌ,Ｓｎ＾４＋＋０．９９μｇ／Ｌ,Ｂｉ＾３＋＋０．１８μｇ／Ｌ相一致。南北极Ｚｎ＾２＋等离子处 相似文献
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Chandralata Raghukumar G. Sheelu P. A. Loka Bharathi Shanta Nair C. Mohandass 《Marine Georesources & Geotechnology》2001,19(1):1-16
In order to assess the impact of deep-sea mining on the in situ benthic life, we measured the microbial standing stock and concentration of organic nutrients in the deep-sea sediments of the Central Indian Ocean Basin in the Indian pioneer area. Sediments were collected using box core and grab samples during September 1996. The total bacterial numbers ranged from 10 10 -10 11 cells per g -1 dry weight sediment. There was a marginal decrease in the number of bacteria from surface to 30 cm depth, though the subsurface section registered a higher number than did the surface. The highest numbers were encountered at depths of 4-8 cm. The retrievable number of bacteria were two orders less in comparison with the direct total counts of bacteria. An almost homogeneous distribution of bacteria, total organic carbon, living biomass, and lipids throughout the depth of cores indicates active microbial and benthic processes in the deep sea sediments. On the other hand, a uniform distribution of total counts of bacteria, carbohydrates, and total organic carbon in all the cores indicates their stable nature and suggests that they can serve as useful parameters for long-term monitoring of the area after the benthic disturbance. Further studies on temporal variability in this region would not only verify the observed norms of distribution of these variables but would also help to understand restabilization processes after the simulated benthic disturbance. 相似文献
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Arne Schnack-Friedrichsen Angela M. Davis Jim D. Bennell Dei G. Huws 《Marine Georesources & Geotechnology》2001,19(4):221-243
The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths. 相似文献
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海上大直径钢管桩打桩过程中,桩周土体受到强烈扰动而发生强度弱化,掌握桩周土体强度弱化规律对于准确预测打桩过程、保证工程安全具有重要意义。为研究土体强度弱化规律,开展了环剪试验模拟打桩对桩周土体的扰动,测试土体强度随剪切速率的变化规律,建立了描述土体强度弱化规律的拟合公式,引入到打桩分析软件中。研究结果表明：土体的强度折减程度不仅与土体本身的性质有关还受到土体的埋深和剪切速率的影响,埋深越深土体强度折减程度越低,剪切速率越高土体强度折减越高,在打桩分析中可采用这里推荐的线性折减方法来模拟不同深度处土体强度的折减规律。 相似文献
14.
Geoacoustic Inversion via Genetic Algorithm and Its Application to Manganese Sediment Identification
An acoustic inversion method using a wide-band signal and two near field receivers is proposed and applied to multiple layered seabed models including a manganese sediment. The inversion problem can be formulated into a probabilistic model comprised of signals, a forward model, and additive noise. The forward model simulates wide-band signals, such as chirp signals, and is chosen to be the source-waveletconvolution plane wave modeling method. The wavelet matching technique, using weighted least-squares fitting, estimates the sediment sound-speed and thickness on which determination of the possible numerical ranges for a priori uniform distribution is based. The genetic algorithm is applied to a global optimization problem to find a maximum a posteriori solution for determined a priori search space. Here the object function is defined by an L 2 norm of the difference between measured and modeled signals. Not only the marginal pdf but also its statistics are calculated by numerical evaluation of integrals using the samples selected during importance sampling process of the genetic algorithm. 相似文献
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Shigehisa Nakamura 《Marine Geodesy》2000,23(1):55-61
Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone. 相似文献
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Oedometer tests have been carried out on 70 undisturbed surficial clays (at approximately 250 mm below the mudline), mostly collected by free-fall corers from sites widely scattered throughout the deep-sea North Atlantic. Acoustic measurements were also made, initially on contiguous samples and ultimately on the same sample using a geophysically instrumented oedometer which also collected electrical resistivity data. Apart from those quiescent areas below the carbonate compensation depth, such as north of the West Indies where very fine clays exist, most of the samples are silty clays whose geotechnical-geophysical properties are dependent on the type of clay minerals present (and their ability to take in moisture), the sand-size fraction, and the quantity of carbonate present. Thus the pure clays have high compressibilities which decrease on the addition of coarse particles, while the converse is true for the acoustic parameters, these increasing with the sand fraction. Using the notion of the intrinsic compression line for all samples, and comparison to it of the measured compression curves, it is clear that, contrary to some previously held ideas, most deep-sea clays are normally consolidated; the addition of carbonate has the effect of creating an open, stronger sediment skeleton. Interestingly, where information is available, the variation with depth of a sample's acoustic velocity follows the void ratio pressure relationship of the compression curve. This allows the construction of an in-situ sediment compression curve using the in-situ geophysical observations. 相似文献
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Phylogenetic diversity and phenotypic characterization of cultivable bacterioplankton isolated from polar oceans 总被引：1，自引：0，他引：1
A set of 27 marine planktonic bacteria isolated from the polar regions was characterized by 16S rDNA sequencing and physiological and biochemical testing. More than half of these bacteria were positive for caseinase, gelatinase and 13-glucosidase, and could utilize glucose, maltose or malic acid as carbon source for cell growth. Twelve isolates expressed nitrate reduction activities. Except for one antarctic isolate BSwlO175 belonging to Actinobacteria phylum, these isolates were classified as γ-Proteobacteria, suggesting that γ-Proteobacteria dominated in cultivable marine bacterioplankton at both poles. Genus Pseudoalteromonas was the predominant group in the Chukchi Sea and the Bering Sea, and genus ShewaneUa dominated in cultivable bacterioplankton in the Prydz Bay. With sequence similarities above 97%, genus Psychrobacter was found at both poles. These 27 isolates were psychrotolerant, and significant 16S rDNA sequence similarities were found not only between arctic and antarctic marine bacteria （ 〉 99% ）, but also between polar marine bacteria and bacteria from other aquatic environments （ ≥ 98.8% ）, including temperate ocean, deep sea, pond and lake, suggesting that in the polar oceans less temperature-sensitive bacteria may be cosmopolitan and have a bipolar, even global, distribution at the species level. 相似文献
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The effect of different fixation and storage protocols on the flow cytometric (FCM) simultaneous analysis of bacterioplankton and phytoplankton in coastal seawater samples (Mediterranean coastal lagoons) was investigated. FCM measurements (cell number, fluorescence and scatter characteristics) were obtained through DAPI staining. Three fixatives [glutaraldehyde (GA), formaldehyde (FA) and paraformaldehyde (PFA)] and two storage (3 months duration) methods (5 °C and −196 °C) were tested. Two dominant populations were detected in studied samples: bacteria and eukaryotic picophytoplankton. Adding fixatives (2% final concentration) appears necessary to obtain FCM exhaustive counts of all the bacteria and phytoplanktonic cells. This was related to the permeation effect of fixatives which allowed a better DAPI staining of the cells. Maximum fluorescence, i.e. optimal staining of the cells was obtained with FA or PFA, and significant lower fluorescences with GA. Fixed samples stored at 5 °C induced rapid cell loss. Only storage in liquid nitrogen of samples fixed with FA or PFA, allows mid-term (≥4 months) preservation of bacteria or picophytoplankton cell numbers, and limited evolution of DAPI-induced fluorescence and scatter characteristics. 相似文献