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31.
阐述把维生素B12生产菌添加到培养水中培养褶皱臂尾轮虫BrachionusPlicatilis的买验。共18株细菌分离于轮虫培养池,其中,有一株产维生素B12的假单胞杆菌TP4对轮虫的生长繁殖有明显的促进作用。把TP4菌株培养后,加入到2L的烧杯和500L的水槽中培养泰国S型轮虫时.在9d(天)和6d(天)中,轮虫密度从124~139和242~288个体/ml增殖到4,417~5,540和1,017~1,254个体/ml,分别比对照组增加了4~6及2~3倍。 相似文献
32.
A tether management system of a winch module in a marine environment is proposed. For the purpose of this study the subsea body is considered as a mass attached at the free end of a long tether which is wrapped around a circular drum controlled by an external torque. The winch is considered mounted on a heaving platform. The effect of the heaving platform on the motions of the drum, tether and attached mass are studied with respect to the longitudinal vibrations of the tether in one dimension. The hydrodynamic effects are considered on the deployed portion of the tether and the tethered mass, both of which are assumed submerged in otherwise still water. The resulting nonlinear system of equations of motion is developed and solved numerically for an example of a marine tether system. The effect of the tether extensibility on the operation threshold of the system is identified. Comparison with an inextensible tether case is provided. The numerical results and their analysis for the retrieval/deployment of the system are presented. 相似文献
33.
Rapid industrial growth and increasing population has resulted in the discharge of wastes into the ocean, wastes which ultimately reach the seabed and contaminate the marine sediments. The soil-contaminants interaction, and their associated physico chemical properties with sediments control the behavior of marine clays. Marine clay deposits of low strength and high compressibility are located in many coastal and offshore areas. There are several foundation problems encountered in these weak marine clays. In this study, experimental work was carried out in the laboratory to stabilize soft marine clays using the lime column technique. Also the lime-induced effects on the physical and engineering behavior of marine clays in sulfate-contaminated marine environment was investigated. Consolidation tests indicate that compressibility of the lime-treated samples was reduced to 1/2-1/3 of the virgin soil after 45 days treatment. The test results also suggest that the lime column technique can be conveniently used to improve the behavior of contaminated marine clay deposits. 相似文献
34.
Evaluation of mine tailings effects on a benthic marine infaunal community over 29 years 总被引:4,自引:0,他引:4
Burd BJ 《Marine environmental research》2002,53(5):481-519
Benthic infaunal and sediment data collected over 29 years were used to examine the extent and geographic range of effects and recovery from submarine tailings deposition. Empirical data were used to determine extreme and moderate effects, and identify near-, mid- and far-field zones. A simple probability test using overlap in frequency distributions was then used to determine less obvious effects, identify "normal" or "reference" conditions, and verify the geographic range of effect zones. Tailings thickness and sediment particulate copper were elevated from the outfall to 16-20 km distant, particularly below discharge depth (50 m). Changes in tailings thickness and copper levels before, during and after mining showed three distinct impact zones below discharge depth: near-field (<5 km from outfall); mid-field (5-16 km); and far-field (20 + km). Consistent faunal declines during mining were noted at sediment particulate copper levels >300 microg g(-1), and sediment tailings thickness > 15-20 cm. Extreme impoverishment at these sediment levels were; < 100 animals/m2, <2.5 g/m2 biomass and <7 taxa per station. No stations with >300 microg g(-1) copper and 20 cm tailings had more than 40 taxa. Amphipods were particularly affected by tailings, with distributions reflecting the instability in sediments from heavy deposition and/or shifting of tailings due to resuspension. The probability testing method assumed that reference conditions existed in far-field stations. There was no difference in abundance distributions between near-, mid- and far-field zones. Total taxa per station during mining was significantly reduced (<45) in both near- and mid-field stations compared with far-field (less than 10% overlap in distributions). One midfield station in Quatsino Sound (23) was in reference condition throughout the study period. Post-closure stations in the near- and mid-field had total taxa numbers approaching far-field conditions (overlap of 62% in distributions). Within 3 years following closure, total taxa values were within the far-field range for all stations sampled. Biomass showed a distinct decline in the near-field during mining, but with more overlap in near-field and far-field distributions (27%) than for total taxa per station, and was returning to far-field conditions in the post-closure years. A multivariate (Bray-Curtis) measure of dissimilarity indicated that the near- and mid-field infaunal compositions were distinct from the far-field during mining (< 10% overlap in distributions). The mid-field composition overlapped more with the far-field in the post-closure years, but the near-field composition did not, suggesting that the mine tailings are still affecting the fauna. The most abundant taxon in each of the reference and near-field station groups both showed significantly distinct relative abundance distributions between near- and far-field stations. In summary, the probability method showed that species richness, biomass, species composition and indicator taxa were useful for differentiating affected and non-affected stations. Polychaetes recolonize stable tailings most quickly, and have dominated the tailings stations in the post-closure years. Amphipods have recolonized sporadically, but seem to be highly sensitive to tailings stability. There was no evidence of recovery in dominant bivalves or echinoderms within three years after mine closure. 相似文献
35.
凡纳滨对虾高密度养殖实验 总被引:3,自引:0,他引:3
实验时间 4 0天 ,放苗密度 5 0 0尾 /m2 、10 0 0尾 /m2 。凡纳滨对虾初体长为 2 .5 88±0 .341cm ,初体重 (0 .2 39± 0 .0 86 ) g。养殖水体中放置筛绢隔断 ,在不换水的条件下 ,监测水体中无机磷、氨氮的变化趋势 ,初步实验高密度和分隔养殖的效果。结果表明 ,高、低密度氨氮、无机磷差异均为极显著 (P <0 .0 1) ;成活率、产量差异均为显著 (P <0 .0 5 )。高、低密度特定生长率 体重 差异不显著 (P >0 .0 5 )。观察到不同时间不同密度凡纳滨对虾对筛绢隔断的反应不同 ,表明对虾能利用隔断筛绢 ,从而有效提高养殖容量 相似文献
36.
Quantum yield for the photochemical production of dissolved inorganic carbon in seawater 总被引:2,自引:0,他引:2
The direct photooxidation of coloured dissolved organic matter (CDOM) to dissolved inorganic carbon (DIC) may provide a significant sink for organic carbon in the ocean. To calculate the rate of this reaction on a global scale, it is essential to know its quantum yield, or photochemical efficiency. We have determined quantum yield spectra, φ(λ), (moles DIC/mole photons absorbed) for 14 samples of seawater from environments ranging from a turbid, eutrophic bay to the Gulf Stream. The spectra vary among locations, but can be represented quite well by three pooled spectra for zones defined by location and salinity: inshore φ(λ)=e−(6.66+0.0285(λ−290)); coastal φ(λ)=e−(6.36+0.0140(λ−290)); and open ocean φ(λ)=e−(5.53+0.00914(λ−290)). Production efficiency increases offshore, which suggests that the most highly absorbing and quickly faded terrestrial chromophores are not those directly responsible for DIC photoproduction. 相似文献
37.
凡纳滨对虾咸淡水养殖系统内细菌群落组成的PCR-DGGE分析 总被引:16,自引:0,他引:16
采用PCR(polym erase chain reaction)-DGGE(denaturing grad ient gel electrophoresis)及传统的微生物培养方法对凡纳滨对虾Litopenaeus vannam ei咸淡水养殖系统内各种环境的细菌群落组成进行了比较研究。传统的微生物培养计数表明,从海湾水、养殖池水到对虾粪样,细菌和弧菌的数量表现出依次增加的趋势,粪样及肠壁中弧菌的数量高出外界水环境1—4个数量级。相对于外界水环境,粪样中有很高的芽孢杆菌孢子含量,但是肠壁定植细菌中不存在芽孢杆菌(孢子)。PCR-DGGE及聚类分析结果表明,从海湾沿岸、养殖池、对虾粪便到对虾肠壁,细菌群落的多样性由高到低,无论是在哪种环境,群落的优势种都十分明显,且只有2—4种。来自同一环境各样品间的细菌群落组成非常相似,来自不同环境的样品,其细菌群落组成差别较大。聚类图上各簇的排列顺序反映了样品在取样空间分布上的毗邻次序和它们的相似程度。 相似文献
38.
随着DNA序列测定技术的飞速发展,人们可以在很短的时间内获得某种生物基因组的全序列。生物体的生命活动主要依赖于基因组的产物——蛋白质组,但是蛋白质组的研究相对于基因组来说却要复杂得多。蛋白质组技术是在细胞内整体蛋白质水平上进行研究,从蛋白质整体活动的角度来研究生命活动的规律。综述了蛋白质组和蛋白质组学出现的背景、起源、概念、研究技术、研究内容、面对的挑战、开展该项研究的意义、陆生动植物和微生物蛋白质组学的研究进展及海洋生物蛋白质组学的研究概况。目前,普通生物方面的蛋白质组工作开展得较多,海洋生物方面却相对滞后。种种迹象表明,开展海洋生物蛋白质组学研究,对揭示生命的奥秘、促进海洋资源的开发都有重大的推动作用。 相似文献
39.
The global community's ability to assess the environmental effects of marine scientific research (MSR) as required by the 1982 United Nations Convention on the Law of the Sea's (UNCLOS) marine environment provisions (MEP) is limited, as shown by experimental activities that intentionally manipulate the marine environment. Such work enhances knowledge of the ocean, but it may also have significant environmental effects. This growing use of the ocean as a laboratory has global scientific, environmental, legal and policy implications. Examined here is the relationship between the MSR and the MEP provisions of UNCLOS. International, science-driven guidelines are proposed. 相似文献
40.
北方地区秋季日本对虾室内高密度精养的试验 总被引:2,自引:0,他引:2
为充分利用每年的8月以后直到翌年3月份都处于休闲状态的育苗场设施资源,笔者于1999年8月在河北黄骅进行日本对虾室内高密度精养的试验。在水温23-28℃、盐度28-32下,8月27日放苗,11月24日收成,养殖时间87d,单位水体产量平均为0.818kg/m^3,平均存活率为50.1%,旬生长率平均为0.75cm,成虾体长平均8cm,饵料系数为2.51,投入与产出比为2.5,平均单位水体创利63.83元/m^3,其结果说明本养殖模式不仅是可行的,而且具有利用率和效益高、实用性强的优点。本文还就相关问题进行了讨论。 相似文献