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1.
根据交换速率连续函数计算法,应用实验室培养法测定了PO_4-P在胶州湾16个站位沉积物-海水界面上的交换速率。结果表明,PO_4-P的交换主要表现为由沉积物向水体的释放,其交换速率一般在 0.1～90 μmol·m~(-2)·d~(-1)范围内。根据 PO_4-P在不同类型沉积物-海水界面上的交换速率,估算出其在胶州湾海底沉积物-海水界面上的交换通量为 9.76×10~6mmol·d~(-1),仅占河流输入量的 24％,可提供浮游植物生长所需磷的 9％±3％。 相似文献
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黄河水中镉（Ⅱ）与悬浮粒子液—固界面交换反应的研究 总被引：4，自引：1，他引：4
本文研究了黄河悬浮粒子与镉（Ⅱ）相互作用的离子交换率（％）—pH曲线，以及河水中赖氨酸存在下对该曲线的影响。主要结果有；（1）镉以Cd（OH）+形式在悬浮粒子上进行阳离子交换，在天然pH下（8．0×8．5），镉离子交换率接近最大值；（2）镉离子浓度由8．9×10－6mol·L－1增加到2×8．9×10－6mol．L－1时，离子交换率降低；（3）浓度为6．8×10－6mol·L－1的赖氨酸对提高离子交换率起促进作用；（4）交换剂为转化沙的镉离子交换率比未转化沙小；（5）海水、金沙江水中悬浮粒子对镉的吸附弱于黄河水。 相似文献
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光对海洋藻类生长的影响——叉鞭金藻对光响应的动力学过程研究 总被引：2，自引：1，他引：2
采用14C同位素示踪法、叶绿素法和细胞计数法,于实验室条件下模拟研究了光照强度对海水中叉鞭金藻生长的影响,以及光转移对叉鞭金藻生长的动力学过程.结果表明,在温度为21℃时,叉鞭金藻光响应曲线初始率为0.028(μmol·m-1·S-1)-1·h-1,最大同化系数为4.15h-1.在光照时间为12hL:12hD条件下,光转移过程叉鞭金藻一级速度常数为2.1×10-2h-1.同化系数、一级速度常数均随温度的变化而变化. 相似文献
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用自行设计安装的磁力浮沉子法密度装置测量溶液密度具有±3×10~(-3)kgm~(-3)的灵敏度,±3.5×10~(-3)kgm~(-3)的精密度。25℃时测定Nacl溶液的密度与Millero测量值平均偏差为2.6×10~(-3)kgm~(-3),求得NaCl的φ_v~0值为16.61(cm)~3mol~(-1)。 对12批中国标准海水及24个稀释中国标准海水的密度测量值(温度在15～25℃之间)与1980年国际海水状态方程计算值之间平均偏差为3.4×10~(-3)kgm~(-3)。实验结果表明中国标准海水及其稀释海水的密度与盐度及温度的关系遵从1980年国际海水状态方程。为中国标准海水作为溶液密度测量标准提供实验依据。 相似文献
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本文应用双硫腙-氯仿萃取质谱同位素稀释法(IDMS)和洁净实验技术相结合,分析了海水中痕量Pb、Cd和Zn,准确度好,精密度优于±3%,Pb、Cd和Zn的检出限分别为6×10-11、6×10-12和2.4×1010g.文中还讨论了过滤、酸化及消解等样品的前处理对海水分析结果的影响. 相似文献
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南沙群岛海域沉积物间隙水营养盐（氮、磷、硅）的研究 总被引：14，自引：2，他引：14
通过1997年11月和1999年7月2个航次对南沙群岛海域的现场调查,实测了南沙群岛深海盆沉积物的孔隙度?间隙水的营养盐含量,估算了沉积物海水界面营养盐的扩散通量?2个航次的沉积物间隙水的NO2-N,NO3-N ,NH4-N,PO4-P ,SiO3-Si含量,1997年冬季航次平均为4.68,43.84,115.68 ,6.85,425.71μmol·L-1,1999年夏季航次(H4SiO4除外)平均为2.72,36.86,31.40,10.10μmol·L-1;平均扩散通量,1997年冬季航次为0.03,-14.07,121.70,0.25,72.54μmol·m-2·d -1,1999年夏季航次(H4SiO4除外)为0.10,-11.74,40.47,-0.56μmol·m-2·d -1?NH 4和H4SiO4 是扩散量最大的2种组分,而HPO2-4 和NO-2的扩散量极小? 相似文献
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厦门西海域水体的细菌动力学研究和环境容量评估 总被引：4，自引：0，他引：4
把通常用在废水生化处理的原理,引入海洋微生物生态研究,应用于环境容量评估.选择3个有关微生物生长和耗氧的动力学模型,通过现场调查和室内试验,确定动力学有关参数值进而估算环境容量.结果表明,若把海水BOD5控制在3mg·dm-3以下,则厦门西海域水体BOD5的毛容量为37t·d-1,现有生态系已经消耗毛容量的25%左右,故净容量为28t·d-1,即该海域每天可接纳相当于28tBOD5的生活污水.此外还发现,耗氧动力学常数K和体系的BOD5浓度呈正相关,海域的总细菌数TB和BOD5浓度的关系呈TB(108dm-3)=9.91×BOD5(mg·dm-3)+1.74(n=32,r=0.5441,p<0.01). 相似文献
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镉对石莼光合作用和呼吸作用及叶绿素含量的影响 总被引：1，自引：0，他引：1
实验表明 ,用含不同浓度镉 (0、5、10、15、2 0、2 5、30× 10 -6)的海水培养石莼 1～ 8d,石莼的光合作用、呼吸作用、叶绿素含量受到了明显的影响。 5× 10 -6的镉培养 3d,光合速率和叶绿素含量明显下降 ;培养时间越长 ,下降幅度越大。低浓度的镉 (5～ 10× 10 -6)对呼吸有促进作用 ,出现了“伤呼吸”;高浓度的镉 (>10× 10 -6)对呼吸有明显抑制作用 ,培养 5d后石莼开始死亡。 相似文献
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对虾养殖围隔生态系浮游动物对细菌的摄食作用 总被引：1，自引：0，他引：1
1997年 6～ 9月在山东省海阳市黄海水产集团养虾场 ,采用围隔实验生态学方法研究了对虾养殖生态系浮游动物对细菌的摄食作用。结果表明 :浮游动物对细菌摄食量为 98～643μg C· dm- 3· d- 1,平均为 ( 2 62± 1 67)μg C· dm- 3· d- 1。浮游动物对细菌摄食量为细菌生产量的 73%～ 1 75% ,平均为 ( 1 1 3± 31 ) %。小于 3μm的浮游动物对细菌摄食量占浮游动物对细菌总摄食量的 1 7% ,其它规格浮游动物 ( >3μm)摄食量占 83%。 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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Derek V. Ellis 《Marine Georesources & Geotechnology》2001,19(1):51-63
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. 相似文献
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G. Parthiban 《Marine Georesources & Geotechnology》2000,18(3):223-235
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. 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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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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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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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. 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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