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四种重金属对海洋钙质角毛藻的毒性 总被引：4，自引：0，他引：4
研究了Ｈｇ＾２＋、Ｃｕ＾２＋、Ｚｎ＾２＋、Ｃｄ＾２＋４种重金属,其单一及４种混合对海洋单胞藻钙质角毛藻Ｃｈａｅｔｏｃｅｒｏｓ ｃａｌｃｕｔｒａｎｓ的毒性效应,结果表明：单一的重金属毒性强于４种重金属混合,而且不同重金属对单胞藻的毒性效应有所不同,其毒性均Ｈｇ＾２＋〉Ｃｕ＾２＋〉Ｚｎ＾２＋〉Ｃｄ＾２＋。 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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四种重金属对Mian状黄姑鱼胚胎和仔鱼的毒性 总被引：4，自引：0，他引：4
本文研究了汞,铜,锌和铬四种重金属对Ｍｉａｎ状黄姑鱼胚胎发育和仔鱼存活的影响。结果表明;在试验浓度范围内,胚胎发育受阻,肥放孵化率显著低于对照组,初孵仔鱼出现不同程度的畸形,这些重金属对Ｍｉａｎ状黄姑鱼仔鱼的毒性强弱依次为Ｈｇ＾２＋〉Ｃｕ＾２＋〉Ｚｎ＾２＋〉Ｃｒ＾６＋。 相似文献
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重金属对几种海洋双壳类和甲壳类生物的毒性 总被引：13，自引：2，他引：13
研究了重金属和污染疏浚物对缢蛏Ｓｉｎｏｎｕａｃｕｌａ ｃｏｎｓｔｒｉｃｔａ稚贝和幼贝，褶牡蛎Ｏｓｔｒｅａ ｐｌｉｃａｔｕｌａ幼虫，甲壳类的卤虫Ａｒｔｅｍｉａｓｐ．幼体和长毛对虾Ｐｅｎａｅｕｓｐｅｎｃｉｌｌａｔｕｓ幼体的毒性，结果表明受试生物的生长，摄食，存活均受到不同程度的影响。各重金属元素对褶牡蛎幼虫，卤虫无节细，长毛对虾糖虾期的毒性顺序为Ｈｇ＾２＾＋＞Ｃｕ＾２＾＋＞Ｚｎ＾２＾＋＞Ｃｄ＾２＾＋＞ 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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于１９９６年５－１２月在实验室用离子交换法对黄河干流内蒙古清水河县喇嘛湾断面黄河水中无机固体粒子与Ｃｕ＾２＋、Ｐｂ＾２＋、Ｚｎ＾２＋、Ｃｄ＾２＋的液－固界面作用进行了研究,得出离子交换率Ｅ％与ｐＨ的关系,找出了４种重金属离子的ｐＨ突跃范围和最大离子交换率,结果表明,在黄河水中４种重金属离子主要以羟基络合物的形式Ｍ（ＯＨ）＾＋与无机固体粒子进行一价阳离子交换,随金属离子浓度增加Ｅ％降低,４种重金属离子与转型沙的交换率大于未转型沙。 相似文献
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罗氏沼虾育苗用水中Mg2+与Ca2+含量及Mg2+/Ca2+对出苗率的影响 总被引：13，自引：0，他引：13
１９９１年３－６月和１９９２年３－６月在南汇县东海水产养殖公司对罗氏沼虾育苗用水调配原则与不同基础水的调配方法进行试验研究。结果表明，育苗用水中Ｍｇ＾２＋与Ｃａ＾２＋含量及Ｍｇ＾２＋／Ｃａ＾２＋必须达到一定的范围，这是调配的基本原则。以鱼塘水作基础水时，需添加６种化学药品，其中Ｍｇ＾２＋与Ｃａ＾２＋含量可适范围分别为３００．０－４４０．０ｍｇ／Ｌ与１７０．０－２４４．０ｍｇ／Ｌ，Ｍｇ＾２＋／Ｃａ＾ 相似文献
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重金属对日本对虾仔存活及代谢酶活力的影响 总被引：6，自引：0，他引：6
本研究测定了铜、锌、镉对不同盐度下日本对虾仔虾的２４ｈＬＣ５０、４８ｈＬＣ５０、９６ｈＬＣ５０,三种金属毒性大小依次为Ｃｄ＾２＋〉Ｃｕ＾２＋〉Ｚｎ＾２＋。对次致死浓度下仔虾的碱性磷酸酶（ＡＫＰ）,酸性磷酸酶（ＡＣＰ）、谷丙转氨酶（ＧＰＴ）、及谷草转氨酸（ＧＯＴ）的活性的测定结果表明：重金属对ＡＫＰ、ＧＰＴ、ＧＯＴ活性有不同程度的抑制作用;肯随着浓度的增高,抑制作用越明显。但对ＡＣＰ活性有激活作用, 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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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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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
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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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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
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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