Management implications of interactions between fisheries and sandeel-dependent seabirds and seals in the North Sea   总被引：4，自引：2，他引：4  

Furness  Robert W. 《ICES Journal of Marine Science》2002,59(2):261-269

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九龙江河口区磷的转移和入海通量   总被引：1，自引：3，他引：1  

陈松  廖文卓  骆炳坤  许爱玉 《台湾海峡》1996,15(2):137-142

1992～1993年4个航次的调查研究结果表明，九龙江河口区总磷的分布和转移受悬浮物含量明显控制。当SPM含量低时，其迁移过程接近理想行为；SPM含量高时则为非理想行为。估算得出，九龙江水体总磷的平均人海通量为1．47×103t／a。其中，溶解态磷为0．43×103t／a，约占29％；颗粒态磷占71％，九龙江水磷的输入以颗粒态为主。溶解态磷的分布，基本上在某一水平上了波动，其入海通量受环境影响很小，可能意味着颗粒磷的缓冲作用。  相似文献   

Sugar and Lipid Components in Sea Foam near Kelp Beds     

Branko  Velimirov 《Marine Ecology》1982,3(2):97-107

Abstract. A component analysis of the sugar and lipid fraction in foam layers around kelp beds on the South African west coast showed the following trends: In the residue of foam drainage of both 12 h and 120 h old foam the sugar fraction is represented by mannose (33–41 %), galactose (4–30%), fucose (3–29%) and glucose (19–26%). With the exception of fucose, the same components could be found in foam filtration. In the lipid fraction the main fatty acids are palmitic (23.3–27.3%), oleic (14.0–5.5%) and timnodonic acid (11.2–9.1%). Selacholeinic acid was only found in 12 h old foam while lignoceric acid could not be located in foam filtration. Against expectation mannitol was not identified in quantifiable amounts in foam samples although it is the dominant component of kelp mucilage, whose presence is of major importance for foam formation. Hypotheses explaining the lack of mannitol are forwarded. Component sugar and lipid content for 11 of foam was calculated and estimation of sugar and lipid content in an average foam patch (volume of 30001) is given. The importance of foam formation as a mechanism for binding and transfer of energy in the marine environment is emphasized.  相似文献   

高速摄影对散体振动的研究     

王树林 《中国海洋大学学报(自然科学版)》1995,(Z1)

以现代高速摄影技术和图像分析以及数据处理方法，针对高效振动磨机中弹性散体工质（如钢棒、球体等）的振动力学进行了深入的探讨和分析，为研究散体动力学和振动超细粉碎过程中的能量分布和传递规律以及能量与物质的相互转换机理奠定了基础，也为相关学科的发展提供了一种可以借鉴的方法。  相似文献   

水平螺旋槽管壁面液膜传热特性的研究   总被引：2，自引：0，他引：2  

武雅洁  梅宁  李艳 《中国海洋大学学报(自然科学版)》2005,35(1):167-172

对管式高效传热传质元件的工程应用进行理论探讨，根据水平螺旋槽管壁面液膜的形成机理及传热特性，通过建立单组分流体的物理和数学模型，得到了液膜速度和厚度解析解，并分析了在蒸发、冷凝时水平螺槽管的表面几何形状对液膜厚度分布的影响。结果表明：液膜的厚度主要受表面张力和槽道表面几何形状的影响，在槽道内弯处较厚，而在槽道起始处较薄，冷凝时与蒸发时相比液膜厚度更薄，液膜分布更均匀。相对于光滑直管，水平螺旋槽管壁面液膜具有更均匀的厚度分布，具有更好的传热传质性能。  相似文献   

热红外波段大气透过率和程辐射的估算方法   总被引：3，自引：0，他引：3  

董仁杰  李铜基  陈清莲  高飞 《海洋技术学报》2006,25(2):78-83

文中对M ONTRAN模型内嵌6种大气模式的主要特性差异进行分析,并以中纬度夏季大气模式为例,分析了主要参数(如水汽、臭氧以及气温等)对估算热红外波段大气透过率和程辐射的影响。论文最后对利用探空数据构造完整大气模式进行了研究。  相似文献   

浮体间距对多浮体系统水动力系数的影响   总被引：2，自引：1，他引：2  

吴广怀 沈庆陈徐均  吴培德 《海洋工程》2003,21(4):29-34

根据三维线性势流理论，采用格林函数法，对多浮体系统的水动力系数进行了数值分析。数值算例中给出了在固定波频下水动力系数与浮体间相对位置关系曲线。水动力系数的变化幅度随着浮体间距离增大而变小。随着浮体间距的变化，水动力系数极值的出现具有明显的规律，相邻的极大值(或极小值)的间距为半个波长或一个波长。  相似文献   

Performance of hemi-cylindrical and rectangular submerged breakwaters   总被引：1，自引：0，他引：1  

Dimitrios G. Stamos  Muhammad R. Hajj  Demetri P. Telionis 《Ocean Engineering》2003,30(6):813-828

A parametric experimental study is conducted to compare the reflection and transmission characteristics of submerged hemi-cylindrical and rectangular rigid and water-filled flexible breakwater models. The results show that, for the rigid breakwaters, rectangular models are more effective than hemi-cylindrical ones in terms of reduction of transmitted waves. As for the flexible breakwaters, the hemi-cylindrical models may give better wave reflection than rectangular ones. However, the energy loss induced by the rectangular breakwaters is much larger and more significant to result in an overall better efficiency in terms of reduction in wave transmission. The effects of internal pressure show that the lowest pressurized flexible models considered in this work are the most effective in the reduction of the transmitted wave height. Higher wave reflection, lower wave transmission and higher energy loss are obtained consistently at the lower submergence depth ratio.  相似文献   

Air-Sea Gas Transfer Velocity in Stormy Winter Estimated from Radon Deficiency     

Hitoshi Kawabata  Hisashi Narita  Koh Harada  Shizuo Tsunogai  Masashi Kusakabe 《Journal of Oceanography》2003,59(5):651-661

Thirteen vertical profiles of ²²⁶Ra and ²²²Rn in the near-surface water were obtained in the western North Pacific in winter, and the gas transfer velocities across the air-sea interface were estimated. The transfer velocities found by applying a steady state model varied widely from 2.1 to 30.2 m day⁻¹ with a mean of 9.4 m day⁻¹. The mean value is almost 5 times higher than that in summer in other oceans, and the maximum value is a record high for world oceans. This is partly due to the inadequacy of the steady state model, which overestimates when stronger winds blow in more recent days than the ²²²Rn half-life of about 4 days. In fact, a strong low pressure zone passed through the station about 2 days earlier, which was one of the low pressure zones that with a period of develop once a week or so in the northwestern North Pacific in winter. Instead of steady-state removal, if half of the radon removal occurred sporadically every 7 days, and the last removal took place two days before the observation, the transfer velocity would be 26 m day⁻¹. Our mean transfer velocity, which is less than 20% different from the steady state value including both overestimated and underestimated values, 9.4 ± 4.8 m day⁻¹, seems to represent the mean state of this region in winter. This suggests that the gas exchange fluxes under extremely rough conditions in the open ocean are larger than those estimated by using a transfer velocity equation with a linear or quadratic relationship with wind speed. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

On the radiation and diffraction of linear water waves by an infinitely long rectangular structure submerged in oblique seas   总被引：1，自引：0，他引：1  

Y.H. Zheng  P.F. Liu  Y.M. Shen  B.J. Wu  S.W. Sheng 《Ocean Engineering》2007,34(3-4):436-450

The radiation and diffraction of linear water waves by an infinitely long rectangular structure submerged in oblique seas of finite depth is investigated. The analytical expressions for the radiated and diffracted potentials are derived as infinite series by use of the method of separation of variables. The unknown coefficients in the series are determined by the eigenfunction expansion matching method. The expressions for wave forces, hydrodynamic coefficients and reflection and transmission coefficients are given and verified by the boundary element method. Using the present analytical solution, the hydrodynamic influences of the angle of incidence, the submergence, the width and the thickness of the structure on the wave forces, hydrodynamic coefficients, and reflection and transmission coefficients are discussed in detail.  相似文献