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1.
研究ｐＨ和Ｃａ（Ⅱ）对砷酸根在海水与ＮａＣｌ介质中对水合氧化物和粘土矿物上交换吸附的影响：（１）在酸性条件下和海水及ＮａＣｌ介质中，砷酸根在针铁矿上的交换率Ｅ（％）—ｐＨ曲线呈平顶峰型、在δ－ＭｎＯ呈峰型、在粘土上分别呈双峰型和肩峰型。这是砷酸根存在多种形式与固体表面发生离子／配位子交换以及介质中阴离子竞争交换吸附共同作用的结果。（２）在碱性条件下的海水介质中，砷酸根与水合氧化物和粘土矿物的Ｅ（％）—ｐＨ曲线都呈Ｖ型，这是因为生成了具有一定结构的液—固界面三元络合物之故。（３）在ＮａＣｌ介质中，Ｃａ加入起促进作用，再次证明液—固界面三元络合物生成机理与Ｖ型曲线的内在关系 相似文献
2.
实验研究海水中天然溶解有机物（ＤＯＭ）在δ－ＭｎＯ２、粘土和二氧化硅上的吸附,海水中溶解有机碳（ＤＯＣ）在δ－ＭｎＯ２、高岭石、伊利石和二氧化硅上的吸附率随ｐＨ的增加而减小。结果表明,在天然海水ｐＨ８．１条件下,海水中天然溶解有机物在这４种固体粒子上的吸附率大小为：δ－ＭｎＯ２（３２％）＞伊利石（１４％）＞高岭石（４％）≈二氧化硅（３％）。根据统计热力学方法得到的公式能够很好地拟合海水中ＤＯＭ在固体颗粒物上的吸附。 相似文献
3.
研究了ｐＨ 和总钼酸根浓度对海水中钼酸根在针铁矿上吸附的影响。钼酸根在针铁矿上的吸附等温线为Ｓ型。假设海水中钼酸根在针铁矿表面的吸附,是在双电层的内Ｈｅｌｍｈｏｌｔ 层中的能量相等的不同位置上进行的,并考虑到吸附的钼酸根之间存在着横向相互作用,由此推导得到的吸附等温式可描述钼酸根在针铁矿上的Ｓ型吸附等温线,并计算得到钼酸根在针铁矿上的最大吸附量为４ ．７６ ×１０－ ５ｍｏｌ／ｇ。钼酸根在针铁矿上的吸附受溶液ｐＨ影响,吸附密度随ｐＨ 的增加而降低。加入到海水中的钼约有２０ ％ 可被水合氧化铁的清除作用所转移。 相似文献
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5.
实验测定了海水中氨基酸存在下Ｃｕ（Ⅱ）在ｒ－ＭｎＯＯＨ上吸附的等温线、Ｃｕ（Ⅱ）％－－ｐＨ曲线和Ｃｕ（Ⅱ）％－氨基酸深度曲线。结果表明，较低浓度氨基酸对Ｃｕ（Ⅱ）在ｒ－ＭｎＯＯＨ上吸附没有影响，而较高浓度氨基酸却起抑制作用，这主要是由于海水中Ｃｕ（Ⅱ）－氨基酸络合反应与ｒ－ＭｎＯＯＨ竞争Ｃｕ（Ⅱ）所致。此外，海水中较高浓度氨基酸只使Ｃｕ（Ⅱ）在ｒ－ＭｎＯＯＨ上吸附的表面分级离子交换稳定常数Ｋｉ（ｉ 相似文献
6.
改性膨润土对赤潮落种及海水中DRP,COD的去除效应 总被引：3，自引：0，他引：3
实验室研究了不同条件制备的改性膨润土对赤潮生物及海水中ＤＲＰ,ＣＯＤ的去除效应,结果表明,改性膨润土有效Ａｌ为１．５％时去除效应最好,经Ｎａ２ＳＯ４,Ａｌ２（ＳＯ４）３改性的膨润土在ｐＨ＝５．５时去除效应最佳,改性膨润土的去除效率随Ａｌ／ＳＯ４比值增加而增加,改性膨润土添加絮凝剂醋甲壳质和Ｃａ（ＯＨ）２提高了去除功效。 相似文献
7.
本文以人工海水和天然海水为介质，研究了Ｃｒ（Ⅲ）被Ｈ２Ｏ２的氧化作用，结果表明，Ｃｒ（Ⅲ）的氧化速率为介质ｐＨ和温度的函数；海水中溶解有机质的存在也将影响Ｃｒ（Ⅲ）的氧化速率，随着海水中腐殖质浓度的增加其氧化速率呈现下降趋势。其原因可解释为腐殖质对Ｃｒ（Ⅲ）的配合作用和对Ｃｒ（Ⅵ）的还原－催化作用。 相似文献
8.
前 言 海洋中溶解有机碳的浓度一般为0.5～2(×10~(-6)),只是海水中无机物的1/10~5,此外尚有更少的固体粒状有机物.海水中有机物的存在量虽然不大,但在许多场合下起着很重要的作用,特别是在液-固界面相互作用中可能起关键作用.许多研究表明,天然水中的颗粒物能显著地吸附有机物,并且在吸附有机物后使其表面带有负电荷,吸附的有机物对微量金属元素的吸附和天然颗粒物的凝聚有着十分重要的影响.因此,研究有机物在悬浮颗粒物上的吸附作用也就显得十分必要. 相似文献
9.
条斑紫菜对无机碳的利用 总被引：4，自引：0，他引：4
于１９９８年３月在青岛太平角采集条斑紫菜,在室内光照强度为１２０μＥ／（ｍ~２·ｓ）的培养架上培养,通过测定其光合作用引起密闭海水体系ｐＨ值及无机碳浓度的变化,借助于各种无机碳利用的抑制剂（Ａｚ、Ｖａｎ、ＤＩＤＳ、ＳＩＴＳ）对其无机碳利用机制进行了研究。结果表明,（１）条斑紫菜可间接吸收ＨＣＯ~（－）_（３）。胞外碳酸醉酶（ＣＡ）催化ＨＣＯ~（－）_（３）水解成ＣＯ_２扩散进入胞内是条斑紫菜无机碳利用的主要形式,占全部无机碳利用的７３％以上。Ａｚ是胞外ＣＡ的抑制剂,可直接检测胞外ＣＡ的存在,它不能透过细胞膜。（２）条斑紫菜可依赖于细胞膜上ＡＴＰ酶对ＨＣＯ~（－）_（３）直接转运。但未发现带Ⅲ蛋白（ｂａｎｄ ３ Ｐｒｏｔｅｉｎ）及 Ｎａ~＋／ＨＣＯ_（３）~（－）协同转运系统的参与。（３）条斑紫菜ｐＨ值补偿点为９．８３,ＣＯ_２补偿点为０．０４μｍｏｌ／Ｌ。 相似文献
10.
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
11.
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
12.
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
13.
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
14.
Coastal inundation associated with extreme sea levels is the main factor which leads to the loss of life and property whenever a severe tropical cyclonic storm hits the Indian coasts. The Andhra and Orissa coasts are most vulnerable for coastal inundation due to extreme rise in sea levels associated with tropical cyclones. Loss of life may be minimized if extreme sea levels and associated coastal flooding is predicted well in advance. Keeping this in view, location specific coastal inundation models are developed and applied for the Andhra and Orissa coasts of India. Several numerical experiments are carried out using the data of past severe cyclones that struck these regions. The simulated inland inundation distances are found to be in general agreement with the reported flooding. 相似文献
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《海洋学报(英文版)》2014,(9):F0003-F0003
<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology, 相似文献
17.
Hoi-Soo Jung Kap-Sik Jeong Yong-Shik Chu Sung-Hyun Park Ki-Hyune Kim 《Marine Georesources & Geotechnology》2001,19(3):181-195
Grain size and water content in box-core sediments from the Clarion-Clipperton fracture zone (C-C zone) in the northeast equatorial Pacific were analyzed in detail to understand the downcore variations across a hiatus between Quaternary and Tertiary layers. Grain-size distributions in the topmost core sediments show two modes: a coarse mode (peaked at 50 μm) and a fine mode (at 2-25 μm). The coarse mode disappears gradually with depth accompanied by the dissolution of siliceous fossil tests, whereas the fine mode coarsens due to the formation of authigenic minerals. Water content increases abruptly across a color boundary between an upper pale brown layer and a lower dark brown layer that is the hiatus between Quaternary and Tertiary layers. Abundant smectites and microvoid molds, which are created by the prolonged fossil dissolution in the underlying sediment, are attributed for the abrupt downcore variation of water content. Overall variations in grain size and water content in the topmost core sediments in the western C-C zone are possibly constrained by the dissolution of biogenic siliceous fossils. Variations in geotechnical properties related to these changes must be considered in the design of nodule collectors. 相似文献
18.
Shigehisa Nakamura 《Marine Geodesy》2001,24(1):27-33
This article concerns an interrelation between the sea levels and the western boundary flow near a tectonic boundary in a local zone in the Northwestern Pacific. In this zone, sea level variations at stations located on the coast facing the Pacific are studied to find the interrelation between variations of the Kurosio flow as an index of the distance of the flow axis off a specific coast. The result is discussed after data processing of the monthly means of the sea levels, and a notice is taken of variations caused by active crustal upheavals during a seismic event, a local earthquake. 相似文献
19.
This study tests the hypothesis that the in situ void ratio of surficial marine sediments may be predicted from shear wave velocity-depth data with a reliability equal to that of other methods currently available. Shear wave velocity is fundamentally controlled by the number of grain-to-grain contacts per unit volume of material and by the effective stress across those contacts. In this study, three previously established empirical formulae are used to predict void ratio from velocity-depth data. Field data were acquired along a transect off the northern Californian coast across which water depth increased from 35 to 70 m and seafloor sediment type varied from sand to silty-sand, respectively. A towed seafloor sled device was used to collect shear wave refraction data, and a marked, systematic decrease in velocity was observed along the line, ranging from 35-70 m/s for the coarse, near-shore material to 25-40 m/s for the finer, offshore deposits. Void ratios predicted from these velocities were compared with data measured directly from box-core samples. Of the formulae used for prediction, two agree remarkably well with the control data. Both predicted and control values increase from 0.6-0.8 for the sandy material to 1.1-1.5 for the silty-sand. Thus, this study does not disprove the hypothesis set and demonstrates the potential of field shear wave velocity-depth data as a means of delineating spatial variation in void ratio for surficial marine sediments in a remote, nondestructive manner. 相似文献
20.
Particulate samples were collected from the Changjiang river system during a flood period, in May 1997, and POC, stable isotope and lipids associated with particles were examined. Results showed the decrease (0.84% ～ 1.88%) of organic carbon content from the upper reaches to the estuary.δ13C values of particulate organic carbon was in the range of -24.9×10-3 to -26.6×10-3, which were close to the isotopic signature of continental C3 vegetation. Total particulate n-alkanes concentrations varied from 1.4 to 10.1μg/dm3,or from 23.7 to 107μg/g of total suspended matter. Fatty acids were present in all the samples, from 1.4 to 5.4μg/dm3, with saturated and unsaturated straight-chain and branched compounds in the carbon number range from C12 to C30. Both δ13C and the ratio of carbon content to nitrogen content indicate the predominance of terrestrial inputs (soil organic matter) among the particles. The biomarker approach has been used to identify the relative portion of terrigenous and autochthonous fraction in the particulate samples. The distribution of fatty acids suggests a striking phytoplanktonic and microbial signal in most particle samples. The terrestrial alkanes are used to estimate the contribution of terrestrial inputs along the mainstream. 相似文献