Preliminary study on different nutrient pools supplies for the phytoplankton growth in the Jiaozhou Bay in China in the fall of 2004     

WANG Dan  SUN Jun  SONG Shuqun  LUAN Qingshan  Joey McMurdie 《海洋学报(英文版)》2007,26(3):110-120

The source and significance of two nutrients, nitrogen and phosphorous, were investigated by a modified dilution method performed on seawater samples from the Jiaozhou Bay, in autumn 2004. This modified dilution method accounted for the phytoplankton growth rate, microzooplankton grazing mortality rate, the internal and external nutrient pools, as well as nutrient supplied through remineralization by microzooplankton. The results indicated that the phytoplankton net growth rate increased in turn from inside the bay, to outside the bay, to in the Xiaogang Harbor. The phytoplankton maximum growth rates and microzooplankton grazing mortality rates were 1.14 and 0.92 d-1 outside the bay, 0.42 and 0.32 d-1 inside the bay and 0.98 and 0.62 d-1 in the harbor respectively. Outside the bay, the remineralized nitrogen (Kr=24.49) had heavy influence on the growth of the phytoplankton. Inside the bay, the remineralized phosphorus(Kr=3.49) strongly affected the phytoplankton growth. In the harbor, the remineralized phosphorus (Kr=3.73) was in larger demand by phytoplankton growth. The results demonstrated that the different nutrients pools supplied for phytoplankton growth were greatly in accordance with the phytoplankton community structure, microzooplankton grazing mortality rates and environmental conditions. It is revealed that nutrient remineralization is much more important for the phytoplankton growth in the Jiaozhou Bay than previously believed.  相似文献   

中国东海2万年来海平面变化分析   总被引：4，自引：0，他引：4  

辛立国  李广雪  李西双  马妍妍 《中国海洋大学学报(自然科学版)》2006,36(5):699-704,698

拟通过中国东海相对海平面与全球海平面对比分析，来获得东海构造沉降数据。但在对比分析的过程中发现，断裂作用对中国东海150m以深海域相对海平面的变化有重要影响。这种作用使东海150m以深海底至少下降了30m，这是我国学者先前误认为中国东海末次冰盛期最低海面位置位于现今海面下150～160m一带的主要原因。在此基础上，进一步对水与冰川重力均衡、沉积物压实和构造沉降作用进行了探讨。结果认为重力均衡不足、沉积物压实作用微弱，构造沉降是造成东海相对海平面与全球海面之间差异的又一重要原因。同时发现东海构造沉降随水深呈规律性变化。断裂作用的表现结果所赋予的更深层次的思考与认识是，在17kaB．P．以前，中国东海水深150～160m一带是1个相对隆起带，其存在对陆架区圈闭和捕获中国大陆古水系和沉积物具有重要意义。  相似文献   

一种优化模糊度搜索方法的研究   总被引：1，自引：0，他引：1  

刘立龙  文鸿雁  唐诗华 《海洋测绘》2006,26(1):37-39,53

对于高精度测量和导航,GPS载波相位整周模糊度的快速求解仍然是一个难点,尤其对于单频接收机。提出一种快速求解整周模糊度的方法,其基本思想采用分步求解,首先应用最小二乘模糊去耦调节法(LAMBDA)搜索出来的模糊度作为初始值,然后应用卫星分组方法降低搜索维数,并应用极大似然准则,构造搜索函数,最后应用最优化原理,搜索出最优的模糊度参数,并从三个方面对其进行检验,即RATIO检验,OVT检验,多项式拟合残差检验。为验证该算法,我们用单频GPS接收机进行了实验,利用本文方法在11 S以内正确确定了模糊度,其基线长误差小于3MM,表明该方法不但可以改进模糊度的搜索速度,而且可以进一步提高其可靠性和成功率。该方法可广泛应用于定向及姿态测量。  相似文献   

Geochemistry and environment evolution of Core E in the Laizhou Bay since last stage of Middle Pleistocene     

Han Deliang  Yu Hongjun  Li Guanbao 《海洋学报(英文版)》2001,20(3):391-399

IwrincrIONOn the evolution of palcoenvironment, salt-water encroachmnt and the distributionof subsurface brine in the LaizhOu Bay area, many researches had been carried out, and muchknowledge abeut the gcolOgical features in this area since Late QUaternary was aCquired' ) (H8nand Wu, l992; Han and Meng, l994; Wen et al. l989). However there was IittIe studyon the sediment geOChemical characteristics since Quaternary. In this Paper, the element strati-graphic characteristics and evolut…  相似文献   

近海工程环境应用中各种风资料的平均时间分析   总被引：5，自引：0，他引：5  

吴增茂  孙士才 《海岸工程》1995,14(3):8-12

本文从近海工程设计应用的需要出发，对于通常使用的不同来源的测风资料平均时间进行了分析，这些资料来源包括：岸边及近海探查与生产设施上的气象台站、天气观测船、浮标、商船气象报、从受灾情况估计出的极大风速以及动力诊断模型估计出的海面风速。  相似文献   

Beneath the surface: Characteristics of oceanic ecosystems under weak mixing conditions – A theoretical investigation     

Aike Beckmann  Inga Hense   《Progress in Oceanography》2007,75(4):771-796

This study considers an important biome in aquatic environments, the subsurface ecosystem that evolves under low mixing conditions, from a theoretical point of view. Employing a conceptual model that involves phytoplankton, a limiting nutrient and sinking detritus, we use a set of key characteristics (thickness, depth, biomass amplitude/productivity) to qualitatively and quantitatively describe subsurface biomass maximum layers (SBMLs) of phytoplankton. These SBMLs are defined by the existence of two community compensation depths in the water column, which confine the layer of net community production; their depth coincides with the upper nutricline. Analysing the results of a large ensemble of simulations with a one-dimensional numerical model, we explore the parameter dependencies to obtain fundamental steady-state relationships that connect primary production, mortality and grazing, remineralization, vertical diffusion and detrital sinking. As a main result, we find that we can distinguish between factors that determine the vertically integrated primary production and others that affect only depth and shape (thickness and biomass amplitude) of this subsurface production layer. A simple relationship is derived analytically, which can be used to estimate the steady-state primary productivity in the subsurface oligotrophic ocean. The fundamental nature of the results provides further insight into the dynamics of these “hidden” ecosystems and their role in marine nutrient cycling.  相似文献   

Estimation of gillnet and hook selectivity using log-linear models   总被引：5，自引：0，他引：5  

Millar  Russell B.; Holst  Rene 《ICES Journal of Marine Science》1997,54(3):471-477

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鸭绿江洪季的河口最大混浊带   总被引：4，自引：0，他引：4  

金惜三  李炎 《海洋学研究》2001,19(1):1-10

对 1 994年 8月在鸭绿江河口的水文和悬浮泥沙的观测资料进行分析。结果表明 ,在洪季鸭绿江河口的最大混浊带 ,出现在第一个河口锋面内侧。它的核心处盐度小于 1 ,从上游带入河口的细颗粒泥沙多数被河口第一锋面截留 ,还有一部分上游来沙穿过该锋面 ,聚集在河口第一和第二锋面之间。垂向密度环流作用和絮凝作用在鸭绿江洪季最大混浊带的维持过程中起着主导作用  相似文献   

Swimming endurance of haddock (Melanogrammus aeglefinus L.) at prolonged and sustained swimming speeds, and its role in their capture by towed fishing gears     

Breen  Mike; Dyson  Jamie; O'Neill  Finbarr G.; Jones  Emma; Haigh  Michael 《ICES Journal of Marine Science》2004,61(7):1071-1079

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一类广义Sine-Gordon方程的概周期解   总被引：4，自引：0，他引：4  

朴大雄  邱汶华 《中国海洋大学学报(自然科学版)》2006,36(6):892-894

用最大值原理和Banach压缩映像原理研究一类广义Sine-Gordon方程的概周期解问题,证明概周期解的存在‖u‖L∞<π2中的唯一性。  相似文献