即墨养虾场虾病暴发前期底质中叶绿素的变化

本文在测定养虾池底质中叶绿素的变化,比较了在３０℃,４０℃,５０℃,６０条件下烘干与不烘干底质样品叶绿素ａ的测定结果。表明随烘干温度上升测定结果的偏差增大,各温度梯度偏差分别为３０℃１３．２４％、４０℃３４．９３％、５０℃５７．１９％、６０℃７６．０３％。而不经烘干处理的样品结果偏差为１．２３％。运用不烘干法对５、６、７月份养虾池底质叶绿素ａ及脱镁叶绿素进行了测定。结果表明在虾暴发前虾池底质中叶绿     

维生素C对水产动物的功用及其保护方法

维生素Ｃ（Ｖｃ），又名抗坏血酸（Ｌ ａｓｃｏｒｂｉｃａｃｉｄ），对水产动物的正常生理生化功能具有重要作用。大多数陆生动物在体内能够合成Ｖｃ，但大多数的水产动物体内不能合成Ｖｃ ,它们对Ｖｃ的缺乏都很敏感。另外 ,在Ｖｃ的化学结构中 ,高度活泼的第２位碳原子上的羟基很不稳定 ,容易被空气氧化。在饲料加工过程中 ,约有８０ %～９８ %的Ｖｃ被破坏 ,此外在包装、贮藏、投喂等环节Ｖｃ也易丧失活性。因此 ,稳定型Ｖｃ已成为国内外水产研究的一个热点。１维生素Ｃ的功用Ｖｃ在生物体内一个重要的生物学功能是参与胶原蛋白的合成。…     

玄参主要环烯醚萜苷热稳定性研究

目的：研究玄参中各主要环烯醚萜苷在干燥过程和水浴加热过程中的稳定性。方法：将4等份玄参叶分别采用室温（20℃）干燥20d及40℃、60℃、80℃直接烘干,5等份玄参根冷浸液不同水浴温度（40℃、60℃、70℃、80℃、90℃）加热1h,HPLC法测定玄参中主要环烯醚萜苷桃叶珊瑚苷、哈帕苷、哈帕俄苷含量。结果：不同烘干温度下测得玄参叶中各环烯醚萜苷含量,以室温及40℃最低,60℃最高,但与80℃差异不明显;玄参根冷浸液不同水浴温度加热1h后,4种成分含量变化不显著。结论：玄参鲜药材干燥温度对其主要环烯醚萜苷含量影响很大,但提取过程中的温度对其影响不大。     

贻贝在不同贮藏温度下磷脂含量变化初步研究

对贮藏在２０℃、５℃、－ １０℃和－ １８℃温度下的鲜活紫贻贝做了磷脂总量变化的研究,运用高压液相和比色法检测了贻贝在不同贮藏温度和时间下的磷脂组分及其含量。发现在－ １８℃贮藏２０ｄ,磷脂总量损失了２４．６４％ ,而在２０℃放置１ｄ,就损失２１．８４％ 。说明磷脂酶活性受温度的影响很大     

栉孔扇贝血淋巴中超氧化物歧化酶和过氧化氨酶活性及其性质的研究

于１９９７年１０月－１９９８年１月,从胶州湾贝类养殖场购买栉孔扇贝,分别采用邻苯三酚自氧化法和过氧化氢法测定了其血细胞和血清中的超氧化物歧化酶（ＳＯＤ）和过氧化氢酶（ＣＡＴ）的活力,并对ＳＯＤ类型的鉴别区分、ＳＯＤ和ＣＡＴ的热稳定性以及温度对ＳＯＤ和ＣＡＴ活力的影响进行研究。结果表明,血细胞中ＳＯＤ和 ＣＡＴ活力分别为３１２．７Ｕ和 １２４．４Ｕ,血清中ＳＯＤ和ＣＡＴ活力分别为１０２．３Ｕ和７３．８Ｕ;冻存１０ｄ后,血清中ＳＯＤ的活力丧失２４．６％,而ＣＡＴ的活力丧失４０．８％;血细胞中ＣｕＺｎ－ＳＯＤ和Ｍｎ－ＳＯＤ的活力分别为１９３．４Ｕ和８２．３Ｕ,血清中仅存在ＣｕＺｎ－ＳＯＤ活性;血清中ＳＯＤ的热稳定性很高,在８０℃下保温３０ｍｉｎ后,酶活力仍很高,而ＣＡＴ的热稳定性较低;血清中的ＳＯＤ和ＣＡＴ的最适温度分别为５０℃和４５℃。     

鲍人工配合饲料稳定性的研究

研究了鲍人工配合饲料加工过程中,CaCl2处理溶液浓度与饲料稳定性的关系,以及不同海水温度对饲料稳定性的影响规律。研究表明,3％～15％的CaCl2处理溶液浓度范围,饲料的稳定性随CaCl2浓度的上升而提高。在15～30℃的范围内,随着海水温度升高,饲料的稳定性逐步下降。由25℃升高至30℃时,饲料的稳定性出现较大幅度的降低。本文的研究结果可作为控制鲍人工饲料稳定性的依据,并生产出符合不同水温要求的系列鲍人工配合饲料。     

密西西比河谷型沉积：是海平面升降造成烃类形成过程中盐水排出的产物吗？

密西西比河谷型沉积：是海平面升降造成烃类形成过程中盐水排出的产物吗？Ｅｉｓｅｎｌｏｈｒ等密西西比河谷型（ＭＶＴ）Ｚ＿ｎ－Ｐ＿ｂ矿一般分布在稳定的克拉通盆地基底隆起之上或其附近。据认为，它们形成于来自盆地深处并向盆边缘移动，其温度在８０°－２００℃卤水...     

南海海底沉积物声学物理参数测定的温度和时间优化研究

海洋沉积物含水率、密度和孔隙度等物理参数是沉积物声学特性研究中的重要指标。由于南海沉积物类型多样、成分复杂, 特别是深海沉积物样品珍贵, 需精确测定沉积物声学及物理参数并无损害地保持沉积物化学性质。文章以黏土、粉砂和砂三种典型海底沉积物为研究对象, 使用环刀法和烘干法, 在不同温度条件下(60℃、80℃、100℃和120℃)测定和分析了这三种沉积物的含水率、密度、孔隙度随烘干时间的变化趋势及特征, 并进行了回归分析和综合研究。结果表明: 1) 对同类型沉积物, 温度越高, 完全失去孔隙水的时间越短, 且失水过程具有阶段性;2) 同一温度下, 三种典型沉积物完全失去孔隙水的时间为t_砂<t_粉砂<t_黏土, 且不同时间段, 失去孔隙水的速率差异较大, 这主要与沉积物的颗粒大小、颗粒间的间隙大小以及烘干后期沉积物中所含的水分均已大部分流失有关;3) 建议声学沉积物样品的烘干温度以80℃左右为宜, 并给出三种沉积物完全烘干的参考时长和临界时间;4) 在温度为80℃时, 将临界时间处的物理参数带入经验方程进行声速预报是可行的。     

数据报告：烘干方法与烘干温度对布莱克海脊沉积物含水量和孔隙率数据的影响

1引言 船上现场对164航次991A、995A和996E孔获取的沉积物进行含水量和孔隙率的测量时,是使用105℃恒温进行烘干的。本项研究主要是为了确认105℃的恒温烘干过程是否造成了测量值的偏高。向干燥的烧杯中加入适量沉积物样品,置于105℃对流恒温烘箱中烘干24小时至36小时（Paull,Matsumoto,Wallace,等,1996）,在船上使用此方法烘干沉积物然后测量含水量,利用此含水量数据,再结合干样的质量和体积值,就可以求算出孔隙率（孔隙的体积／样品的总体积）值,许多其它项目的研究都应用了这些数据。     

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。     

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.     

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.     

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.     

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。     

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.     

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.