珠江口海水中的硼和锶的行为研究

采用作者研究的ＯＰ－ 乳化剂增敏姜黄素分光光度法测定海水中的溶解硼,用ＩＣＰ－ ＡＥＳ法测海水中的硼和锶。发现在珠江口海水盐度２．６８６ ～２５ ．７２２ ,氯度１ ．４４０ ～１４ ．１３６ 为０．２１５ ～０ ．２２９ｍｇ·ｋｇ－ １ ,平均值为０ ．２２４±０ ．００５ｍｇ·ｋｇ－ １ ｍｇ·ｋｇ－ １７ ．６４ ,Ｓｒ（ｍｇ·ｋｇ－ １）／Ｃｌ 比值为０．３８０ ～０ ．６６３,平均值为０ ．４０４ ±０ ．０１６ ,两者皆在大洋海水自然变动范围之内。珠江口海水中的硼和锶浓度与海水盐度或氯度均有很好的线性关系。珠江口外南海海水盐度３２ ．９２３ ～３３．４４６, 氯度１８ ．２４１ ～１８．５５８ ,Ｂ浓度为４ ．０２ ～４ ．２４ｍｇ·ｋｇ－ １ ,Ｓｒ 浓度为７．６４ ～７ ．７０ｍｇ·ｋｇ－ １ 。珠江口海水实验数据统计回归线与理论释线比较后表明,珠江口海水中硼与锶均具有良好的保守性质,珠江口海水中的硼和锶主要来自湾外海海水潮汐输入。     

胶州湾海水中硼的研究

首次实验研究胶州湾海水中的硼,胶州湾表层海水中硼的浓度为３．２４ ～３ ．８７ｍｇｋｇ－ １ ,Ｂ／Ｃｉ比值为０ ．１８１ ～０．２１５ ,平均值为０ ．２０４ ±．０ ．００９ 。Ｂ／Ｓ比值为０ ．１００～０ ．１２０,平均值为０ ．１１３ ±０．００５。湾内硼的分布,低值区在李村河口沧口湾附近,而在湾的东西两侧、东北角及湾口区域海水中硼浓度则较高。湾内海水中的硼主要靠湾外海潮输入。因湾内无常年径流流入,盐度分布变化小,硼浓度随盐度及氯度变化不明显。相对于北黄海水,胶州湾海水硼平均迁出量８．６５％ ,胶州湾海水中的硼表现为非保守性质。     

杭州湾海水密度研究

用磁力浮沉子密度测量装置,在１５ ～２５ ℃之间的三个温度下测定了杭州湾３０ 个水样的密度。结果表明,测定值皆高于相应条件下国际标准海水状态方程的计算值,在海水盐度范围５．５６～２６ ．４ ,密度平均偏差值为２８ ．２ ～１２０ ．５ ×１０－ ３ｋｇ／ｍ３ 。测定密度和计算密度的偏差随盐度的降低而增大,与盐度的变化成直线相关;与（Ｃａ２ ＋ ）／Ｓ和比碱度之间皆呈指数曲线相关。杭州湾海水枯水期和丰水期水样的（Ｃａ２ ＋ ）／Ｃｌ 比平均值分别超出大洋水平均值２８ ．８％ 和２０ ．６％ ;杭州湾海水枯水期和丰水期的比碱度平均值分别超出大洋水平均值６０ ．３ ％ 和３０２ ％ ;（Ｍｇ２ ＋ ）／Ｃｌ 比、枯水期水样ＳＯ２ －４ ／Ｃｌ 比及Ｓｒ２ ＋ ／Ｃｌ 比与大洋水平均值相同或相近,丰水期水样ＳＯ２ －４ ／Ｃｌ 高出大洋水平均值７ ．１ ％ ;结合主要离子在湾内平面分布图,得出杭州湾海水高的Ｃａ２ ＋ ／Ｃｌ 比、比碱度和ＳＯ２ －４ ／Ｃｌ 比,除了受江水输入影响以外,主要还是受湾北岸工业区废水排放的影响。并首次给出了杭州湾海水的密度公式。     

杭州湾海水碱度研究

用ｐＨ法测定了杭州湾海水的碱度。结果表明,１９９４ 年５ 月份,杭州湾海水在盐度１２ ．０９７～２６ ．３９７ 之间的碱度变化范围为１．５５ ～２．２３ｍｍｏｌ．ｄｍ － ３ ,平均值为１ ．７５７ｍｍｏｌ．ｄｍ － ３ 。相应的比碱度变化范围为０．１０６ ～０ ．３２４,平均值为０．２０２ ． 碱度高值出现在北岸上海石化总厂附近。因受北岸工业废水排放影响,湾内碱度自西北向东南降低。丰水期湾内海水比碱度显著增大,主要受径流的影响。枯水期湾内碱度和比碱度与盐度或氯度呈负相关关系。     

伯劳特湾海水中~(239)Pu的浓度

伯劳特湾的表层海水中,２３９Ｐｕ的浓度为１３．０±２．８μＢｑ／ｄｍ３,与巴芬湾和拉布拉道海表层海水中的浓度基本相同。其中溶解２３９Ｐｕ的浓度为６．９３±１．８μＢｑ／ｄｍ３,占海水中２３９Ｐｕ总浓度的５３×１０－２;悬浮物中２３９Ｐｕ的浓度为６．０７±３．３μＢｑ／ｄｍ３,占总浓度的４７×１０－２。底层海水中２３９Ｐｕ的浓度为３１．７±４．７μＢｑ／ｄｍ３,２３８Ｐｕ的浓度为０．７８±０．７０μＢｑ／ｄｍ３,２３８Ｐｕ／２３９Ｐｕ的比值为０．０２４,这可能是表层沉积物重悬浮造成的。     

海水中Sr同位素组成变化的环境意义与Sr同位素地层学

１海水中Ｓｒ同位素组成变化Ｓｒ是海水中的一种常量组分，现代海水中含量为７．９ｍｇ／ｋｇ，总量约为１．２１×１０１７ｍｏｌ。海水中Ｓｒ的主要来源包括以下几种：首要是河水来源，河水将其流域内岩石风化产生的大量溶解Ｓｒ２＋带入海水中，这一部分的Ｓｒ通量约为３．０×１０１０ｍｏｌ／ａ，Ｓｒ／８６Ｓｒ比值现代平均值为０．７１１；其次为海底水岩界面交换所带入，其中主要通过海底扩张导致热液输入以及海底玄武岩的风化作用而输入，这一部分Ｓｒ通量为１．２×１０１０ｍｏｌ／ａ，３７Ｓｒ／３６Ｓｒ平均为０．７０５；另外…     

用磁化水培养等鞭藻3011的初步研究

本文主要报道不同磁场强度的磁化水对等鞭藻繁殖作用的影响。１材料和方法安排５组磁场强度，分别为０．０５，０．１，０．３，０．６，０．９Ｔ，一个对照组。５０００ｍｌ的三角烧瓶６个。对海水进行沉淀、沙滤、陶瓷过滤，经磁化水器后，即为磁化水（不煮沸），尔后加入营养盐ＮａＮＯ３６０ｍｇ；ＫＨ２ＰＯ４４ｍｇ；ＦｅＣ６Ｈ５Ｏ０．５ｍｇ；ＮａＳｉＯ３５ｍｇ；ＶＢ１１００ｕｇ；ＶＢ１２０．５ｕｇ；溶于１０００ｍｌ海水中煮沸。室温１５～１８．５℃，光照２４０～２１６０１Ｘ，每天２４ｈ，，培养期间每天搅瓶６次。每天上…     

珠江口海水密度的研究

用磁力浮沉子密度测量装置,在１５ ～２５ ℃之间的三个温度下测定了珠江口２０ 个水样的密度。结果表明,测定值皆高于相应条件下国际标准海水状态方程的计算值,在海水盐度范围０．０８～３３ ．４４６ ,密度平均偏差范围为２ ．４ ～５４．０ ×１０ － ３ｋｇ／ｍ３ 。测定密度和计算密度的偏差随盐度的降低而增大,与盐度的变化成直线相关：与（Ｃａ２ ＋ ）／Ｓ、ＳＯ４２ － ／Ｓ比和比碱度之间皆呈指数曲线相关。珠江口水样（Ｃａ２ ＋ ）／Ｃ１ 、ＳＯ４２ － ／Ｃ１ 和比碱度平均值分别超出大洋水平均值１７ ．８ ％ 、８ ．２１ ％ 和１５２ ％ ,其余的Ｎａ ＋ ／Ｃ１、Ｋ＋ ／Ｃ１ 和Ｓｒ２ ＋ ／Ｃ１ 比值与大洋水无明显差别,基本类同。珠江口海水的高碱度、高（Ｃａ２ ＋ ）／Ｃ１ 和高ＳＯ４２ － ／Ｃ１ 是造成其海水密度正偏差的主要因素。经计算机拟合,首次导出了珠江口海水密度的状态方程,该方程计算值与实验值的平均标准偏差为±２．５×１０－ ３ｋｇ／ｍ３ 。     

龙口湾近岸水质现状

为了解龙口湾水质现状,对其近岸布点进行报连续站与大面站的水质监测,结果表明,海域水质处于良好状态。主要污染物为营养盐、石油类,但在该海域基本不超标。海域无机氮的平均值为０．１６８ｍｇ／Ｌ,无机磷的平均值为０．０１５ｍｇ／Ｌ,石油类的平均值为０．０３９ｍｇ／Ｌ,均属于一类海水水质。     

光度法测定低含量有机硫化合物

提出用氧瓶燃烧－光度法来测定有机物中硫含量的定量分析方法，在低硫酸根浓度范围内（４～２５ｍｇ／ｌ），在浓碱条件下ＭＴＢ（甲基百里酚蓝）的吸光度与硫酸根浓度在４６０ｎｍ波长处呈正相关，而在６００ｎｍ（或６１０ｎｍ）处Ｂａ－ＭＴＢ络合物的吸光度与硫酸根浓度呈负相关。该方法标准偏差低于０．５ｍｇ，／ｌ．变异系数低于３％，回收率为９５－１０７％。     

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.     

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.     

A Review of Some Environmental Issues Affecting Marine Mining

This article reviews information recently available from existing marine and coastal mining for responses to environmental issues affecting marine mining at different depths. It is particularly but not exclusively concerned with those issues affecting seabed biodiversity impact and recovery. Much information has been gathered in the past 10 years from shallow mining operations for construction aggregate, diamonds, and gold, from coastal mines discharging tailings to shallow and deep water, and from experimental deep mining tests. The responses to issues identified are summarized in a series of eight tables intended to facilitate site-specific consideration. Since impacts can spread widely in the surface mixing layer SML, and can affect the biologically productive euphotic zone, the main issues considered arise from the depth of mining relative to the SML of the sea. Where mining is below the SML, the issue is whether it is environmentally better to bring the extraction products to the surface vessel for processing (and waste discharge), or to process the extraction products as much as possible on the seabed. Responses to the issues need to be sitespecific, and dependent on adequate preoperational environmental impact and recovery prediction. For deep tailings disposal from a surface vessel, there are four important environmental unknowns: (1) the possible growth of "marine snow" (bacterial flocs) utilizing the enormous quantities of fine tailings particles (hundreds or thousands of metric tons per day) as nuclei for growth, (2) the possibility that local keystone plankton and nekton species may migrate diurnally down to and beyond the depth of deep discharge and hence be subjected to tailings impact at depth, (3) the burrow-up capability of deep benthos and their ability to survive high rates of tailings deposition, and (4) the pattern and rate of dispersion of a tailings density current through the deep water column from discharge point to seabed. Actions to obtain relevant information in general and site-specifically are suggested.     

Increased Particle Fluxes at the INDEX Site Attributable to Simulated Benthic Disturbance

Particle fluxes were measured 7 m above the sea bottom during the predisturbance, disturbance, and postdisturbance periods by using time series sediment traps attached to seven deep-sea moorings deployed in the INDEX experiment site in the Central Indian Basin. The predisturbance particle fluxes varied between 22.3 to 55.1 mg m -2 day -1 . Increased and variable particle fluxes were recorded by the sediment traps during the disturbance period. The increase observed was 0.5 to 4 times more than the background predisturbance fluxes. The increases in particle fluxes (~4 times) recorded by the sediment trap located in the southwestern direction (DMS-1) were the greatest, which could be the result of preferential movement of resuspended particles generated during the deep-sea benthic disturbance along the general current direction prevailing in this area during the experimental period. Also, the traps located closer to the disturbance area recorded greater fluxes than did the traps far away, across the Deep Sea Sediment Resuspension System path. This variability in recorded particle fluxes by the traps around the disturbance area clearly indicates that physical characteristics such as grain size and density of the resuspended particles produced during the disturbance had an important effect on particle movement. The postdisturbance measurements during ~5 days showed a reduction in particle fluxes of ~50%, indicating rapid particle settlement.     

Phylogenetic diversity and phenotypic characterization of cultivable bacterioplankton isolated from polar oceans

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.     

Determination of In Situ Sediment Shear Strength from Advanced Piston Corer Pullout Forces

The advanced piston corer (APC) has been used by the Ocean Drilling Program since 1985 for recovering soft sediments from the ocean floor. The pullout force measured on extracting the core barrel from the sediment is shown to correlate with the average shear strength of the sediment core measured in the ship's laboratory. A simple rule of thumb is derived relating the shear strength of the sediment to the pullout force. Multiple APC holes at individual sites allow the consistency of the pullout measurements to be assessed. The effects of different operational procedures during APC coring are also explored. Although generally applicable, the correlation between pullout force and laboratory measurements of shear strength breaks down for some APC holes, possibly because of the disturbance of some sediment types during the APC coring process. A better understanding of the physical process of APC coring, and its effect on the properties of the sediment both inside and immediately outside the core barrel, would indicate what confidence can be put on the measurement of pullout force as a way of evaluating the in situ shear strength of deep sea sediments.     

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.