海水中碳酸根与固体粒子的相互作用

本文研究了海水中碳酸根在固体粒子上的吸附。碳酸根在各种因素颗粒物上的吸附程度上大小顺序为：赤铁矿〉δ－ＭｎＯ２〉水锰矿〉ＳｉＯ２,最大吸附量可达到约２ｍｇＣ／ｇ吸附剂,且最大吸附值均在天然海水ｐＨ（ｐＨ８）左右。在低ＰＨ时,碳酸根对ＮａＣｌ介质中砷酸根的吸附没有影响,在高ｐＨ时,则降低了砷酸根在固体颗粒物上的吸附量,因此碳酸根的存在对其他阴离子的吸附会产生竞争作用。     

海水中磷酸盐在固体粒子上阴离子交换作用──海水中磷酸盐-固体粒子相互作用的V形交换率-pH曲线

于１９９０年２月在青岛鲁迅公园采得海水样品；１８９年５月在南京采得伊利石样品，在苏州有得高岭石样品；１９９０年３月实验室合成针铁矿和δ－ＭｎＯ３样品。用振荡平衡实验、离心分离方法和光度分析方法测定３种电溶液（ＮａＣｌ溶液、ＮａＣｌ－ＣａＣｌ２溶液和海水）中酸盐在上述４种固体粒子上的交换率－ＰＨ曲线。测定结果表明，海水中磷酸盐在固体粒子上的交换率－ＰＨ曲线为Ｖ形，并建立阴离了液－固界面作用的交换率－     

海水中天然溶解有机物在针铁矿上的吸附

于１９９６年３月在青岛小麦岛采得天然海水样品,在实验室合成针铁矿样品。用振荡平衡实验和紫外／过硫酸钾法测定了海水中溶解有机物在针铁矿上吸附的等温线和交换率－－ｐＨ曲线,并讨论了天然溶解有机物的吸附对海水中溶解有机碳分布的可能影响。测定结果表明,溶解有机物在针铁矿上的吸附等温线为Ｌａｎｇｍｕｉｒ型,当吸附达到最大值时,在针铁矿表面能够形成有机物单覆盖层。ｐＨ能影响溶解有机碳（ＤＯＣ）在针铁矿上的吸附     

海水中氨基酸对Cu（Ⅱ）在r—MnOOH上吸附的影响

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     

砷酸根的液—固界面交换吸附研究——pH和Ca(Ⅱ)的影响

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     

水溶液中二甲基硫的化学氧化过程研究

实验研究水溶液中二甲基硫（ＤＭＳ）和Ｈ２Ｏ２进行氧化反应的动力学。结果表明ＤＭＳ被Ｈ２Ｏ２氧化的速率会受到介质、ｐＨ以及重金属离子的影响。其二级反应速率常数为２．２１×１０－２～４．９０×１０－２Ｌ·ｍｏｌ－１·Ｓ－１．Ｈｇ２＋的存在会加快反应速率，特别在人工海水条件下十分明显。ＤＭＳ易被Ｈ２Ｏ２氧化的事实说明，在海水中化学氧化过程会对ＤＭＳ的浓度和分布产生重要影响     

海水中液－固界面上负离子分级交换吸附研究──Ⅰ．E（％）－pH关系曲线和新的N－型曲线

本文研究了海水中钼（Ⅵ）与粘土矿物（高岭石、蒙脱石）、水合氧化铁（赤铁矿、无定形氧化铁）和水合氧化锰（水锰矿、相互作用的交换百分率Ｅ（％）－ｐＨ曲线．钼在这三类固体粒子上的Ｅ（％）－ｐＨ曲线分别为新发现的Ｎ－型曲线，以及峰型和反Ｓ型曲线．其中Ｎ－型曲线在负离子交换吸附文献中尚未见报道，本文提出用＂静电交换和分级离子／配位子交换共同作用＂的观点作理论解释．峰型和反Ｓ型Ｅ（％）－ｐＨ曲线可用固－液界面上负离子交换吸附作用解释．钼（Ⅵ）在这三类粒子上的交换能力顺序为：水合氧化锰＞水合氧化铁＞粘土矿物．     

海水中液－固界面上负离子分级交换吸附的研究 Ⅱ.交换吸附等温线和新的N－型曲线

本文研究了海水中钼（Ⅵ）与粘土矿物（高岭石、蒙脱石）、水合氧化铁（赤铁矿、无定形氧化铁）和水合氧化锰（水锰矿、δ－ＭｎＯ＿２）相互作用等温线，钼（Ⅵ）－粘土矿物体系所得是一种具有极大值的Ｎ－型等温线，钼（Ⅵ）－水合氧化物体系所得是具有一个拐点和两个台阶的＂台阶型＂等温线。这两类等温线在负离子交换吸附文献上均尚未见报道。Ｎ－型等温线的产生是因溶液中钼（Ⅵ）的复杂存在形式和负离子交换机理复合作用的结果。＂台阶型＂等温线的形成则是氧化物表面存在着几类能量不同的羟基分级交换吸附的结果。     

海水pH对疏浚物中重金属释放的影响

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。     

黄河水中无机固位粒子与4种重金属液—固界面的交换作用

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。     

Microbial Biomass and Organic Nutrients in the Deep-Sea Sediments of the Central Indian Ocean Basin

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.     

Assessing the Validity of Seismo-Acoustic Predictor Equations for Obtaining Seabed and Sub-Surface Sediment Physical Properties

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.     

海上大直径钢管桩打桩过程中桩周土强度弱化研究

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。     

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.     

Interannual Sea Level Variations and Annual Tides in the Northwestern Pacific

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.     

Flow Cytometric Analysis of Coastal Lagoon Bacterioplankton and Picophytoplankton: Fixation and Storage Effects

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.     

INFORMATION FOR AUTHORS

<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,     

Deep-Sea Sediment Compression Curves: Some Controlling Factors, Spurious Overconsolidation, Predictions, and Geophysical Reproduction

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.