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通过求解海冷水团叶绿素一维模式控制方程,首次对风搅拌混合、潮混合和光衰减强度的影响机制进行了解析研究。结果表明,湍流湿合过程和光的衰减强度对叶绿素夏季垂向分布结构具有重要影响。增强海面风搅拌合作用的结果,导致叶绿素表层分布趋于均匀;增强潮温合,导致叶绿素最大值增加,最大值的位置向海面抬升;减少光的衰减强度,导致叶绿素最大值增加,最大值的位置下沉。 相似文献
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Species composition and spatial distribution of euphausiids of the yellow sea and relationships with environmental factors 总被引:1,自引:0,他引:1
Won Duk Yoon Joon Yong Yang Donghyun Lim Sung Hwan Cho Gyung Soo Park 《Ocean Science Journal》2006,41(1):11-29
We investigated species composition and spatial distribution of the euphausiid community in the Yellow Sea and identified
the relationship with environmental factors (temperature, salinity, chlorophyll a, nitrate, phosphate, and silicate) using
bimonthly data from June, 1997 to April, 1998. The environment varied during the sampling period. In warm seasons, thermocline
was well developed rendering lower temperature and higher salinity and nutrient concentrations in the bottom layer. During
cold seasons the water column was well mixed and no such vertical stratification was noted. Horizontal distribution of temperature,
however, differed slightly between near-coast and offshore areas because of the shallow depth of the Yellow Sea, and between
southern and northern areas because of the intrusion of water masses such as Yellow Sea Warm Current and Changjiang River
Diluted Water. Four euphausiid species were identified:Euphausia pacifica, E. sanzoi, Pseudeuphausia sp. andStylocheron affine. E. sanzoi andS. affine were collected, just one juvenile each, from the southern area in June and December, respectively.Pseudeuphausia sp. were collected in the eastern area all the year round except June.E. pacifica occurred at the whole study area and were the predominant species, representing at least 97.6% of the euphausiid abundance.
Further, the distribution pattern of the species was varied in regards to developmental stages (adult, furcilia, calyptopis,
egg). From spring to fall,E. pacifica adults were abundant in the central area where the Yellow Sea Bottom Cold Water prevailed. Furcilia and calyptopis extended
their distribution into nearly all the study area during the same period. From late fall to winter, adults were found at the
near-coastal area with similar pattern for furcilia and calyptopis. The distribution pattern ofE. pacifica was consistent regarding temperature, salinity, and three nutrients during the sampling period, whereas chlorophyll a showed
a different pattern according to the developmental stages. The nutrients should indirectly affect via chlorophyll a and phytoplankton
concentration. With respect to these results, we presented a scenario about how the environmental factors along with the water
current affect the distribution ofE. pacifica in the Yellow Sea. 相似文献
55.
基于GIS的中国东南沿岸海域海产腹足类性畸变与有机锡污染查询显示系统 总被引:2,自引:0,他引:2
本研究工作采用基于组件式集成方案的ArcInfo GIS软件、Microsoft Access数据库、MapObjects 2.0软件、AutoCAD软件、VB6.0开发语言作为软件平台,以Legend Pentium Ⅲ(933)作为硬件平台,利用ADO数据接口实现与属性库连接,通过ShellExecute函数达到与ArcView软件、相关网址连接,在此基础上建立了中国东南沿岸海域海产腹足类性畸变与有机锡污染查询显示系统,并使其具有显示、缩放、温游、定位、查询、统计、分析、编辑、输出等功能。这是将GIS技术应用于海洋生态系统的调查、管理和保护的新尝试。 相似文献
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Beach nourishment is an environmentally preferred method of shore protection, but the annual sand requirement may lead to substantial maintenance costs. The shoreline processes, involving the surf zone, beach and dune, are reviewed with the aim of reducing the annual sand requirement of eroding shorelines. It is shown that surf zones with equilibrium profiles, on which the wave energy conversion is evenly distributed across the surf zone, from experience for given conditions indicate least loss of sand. On steep, eroding shorelines it may be difficult to establish an equilibrium profile. For such cases, the use of perched surf zones is recommended, which are supported at the seaward limit by an underwater sill. For reduction of littoral transport, the use of pervious pile groynes is recommended. These are arguably more efficient than impervious groynes. The sand loss from a usually dry beach by raised water levels is shown to be a function of the beach slope and is least when the storm waves at raised water levels do not cut an erosion escarpment. The loss of sand from a dune by infrequent severe storm tides can be prevented with the aid of a built-in membrane. These sand losses are usually large and constitute an uneconomic use of this sand resource. The proposed concepts and measures are linked to existing knowledge, augmented by data from the large wave flume (LWF) in Germany and field data from the North and Baltic Sea coasts. 相似文献
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胶州湾营养盐的现状和变化 总被引:28,自引:3,他引:28
报道了1991年5月至1994年2月12个航次胶州湾NO3-N,NO2-N,NH4-N,PO4-P和SiO3-Si的时空分布基本特征,60年代于至90年代的变化表明,胶州湾营养盐的浓度和分布已发生显变化。尤其从60年代至80年代,30年来,胶州湾中东部水城PO4-P,NO3-N和NH4-N浓度分别增加2.2,7.3和7.1倍,TON浓度也增加了3.5倍,TIN/PO4-P从10增加至24.2;T 相似文献
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病毒是非常微小的简单生物, 不能独立生存, 必须借助宿主细胞完成自身的繁衍。病毒侵染进入细胞后, 通常借助于微管通过黏稠的细胞质运动到特定的复制位点。然而, 有关病毒依赖微管运动行为的精细动态研究还比较少。石斑鱼虹彩病毒(Singapore grouper iridovirus, SGIV)为虹彩病毒科蛙病毒属的一个新种, 是海水养殖鱼类的重要病毒性病原, 对海水养殖业造成重大经济损失。利用单粒子示踪技术实时追踪了SGIV病毒粒子沿微管运动的行为, 观察到SGIV在细胞边缘至微管中心之间的双向运动, 最高瞬时速度约0.2μm·s-1, 均表现为主动运输。病毒粒子运动至微管交叉位置会减速迂回, 而后或受限于此, 平均运动速率约0.008μm·s-1, 或通过交叉处继续快速运动, 最高瞬时速度为0.2μm·s-1。同时, SGIV感染会影响微管的形态结构, 随着SGIV感染, 微管逐渐围绕细胞核和病毒加工厂形成环状结构。研究结果初步揭示了SGIV病毒和细胞微管之间相互作用的复杂过程, 丰富了我们对虹彩病毒胞内生命活动的认识, 有助于深入地理解海水鱼类虹彩病毒感染致病机理。 相似文献
60.
本文根据胜利二号极浅海步行坐底钻井平台的作业和工作环境特点,进行了防腐措施研究,设计了切合实际的防腐措施。该平台在海上作业近四年进坞修理,经观测防腐情况良好。 相似文献