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201.
厦门筼筜港的形成与演变   总被引:3,自引:0,他引:3  
本文根据实际调查的资料,概述了筼筜港区的地质地貌特征,重点论述了第四纪沉积物的成因和时代,阐述了该区的形成与演变过程,把它划分为5个发育阶段。  相似文献   
202.
This paper describes a numerical method for calculating the two-dimensional hydrodynamic coefficients of one or two infinitely long, arbitrary cylinders forced to oscillate in or below the free water surface. The oscillation modes, amplitudes and phases of the cylinders may be different from one another. Finite water depth and a quay can be taken into account. Special consideration has been given to the radiation boundary conditions.The computer program developed has been tested in various two-dimensional boundary situations; it has produced results in good agreement with results obtained by other methods.  相似文献   
203.
本文通过计算和对比分析,得到1991年春、夏江淮地区特大暴雨形成的五个基本特征:西北太平洋上副高显著偏西、偏北;较弱的西南季风与东南气流汇合成强西南气流伸向江淮地区;偏东风与强西南风形成的辐合带在江淮地区维持;江淮地区对流层中下部为强上升运动、上部为辐散;130°E附近南半球向北半球的较强越赤道气流持续。  相似文献   
204.
真鲷Pagrosomus major Temminck et Schlegel早期发育阶段游泳行为的发育可以分为:(1)旋转式运动;(2)阶梯型运动;(3)间断式水平运动和滑翔;(4)巡游以及(5)疾游五种类型。前期仔鱼的摄食方式主要是伴有甩头动作的前冲摄食;后期仔鱼的摄食主要有两种类型:一种是身体弯成S形的“S攻击型”;另一种为不作摄食姿势的“咬食攻击型”。摄食方式随着发育水平和饵料种类的不同而异。文中对发育过程中出现的攻击行为、护食行为、互食行为、猝死现象亦进行了描述。并对游泳、摄食以及各种行为的生态意义和实际意义进行了讨论。  相似文献   
205.
大民屯凹陷地层水水文地质特征与油气聚集关系   总被引:6,自引:0,他引:6  
对大民屯凹陷前第三系潜山、下第三系沙河街组地层水化学场研究发现,本区油田水总矿化度及二价阳离子浓度偏低,地层水总矿化度具有明显的垂向分带性,水体主要为陆相成因并受地表水渗入的影响较大,变质程度高,油田水的演化与盐类的溶解有关。该区地层水的流动受断裂和沉积砂体的控制,在水头压力、浮力动力场控制下其流动样式和分布规律反映了凹陷内油气的运聚规律,可为本区自生自储、新生古储式油气藏的判别提供有利证据。  相似文献   
206.
沿海与内陆地下卤水对比分析   总被引:1,自引:0,他引:1  
分析对比我国滨海与内陆地下卤水的分布、成因及其水文地球化学特征,指出不同成因的地下卤水具有不同的水质.  相似文献   
207.
Hydrodynamic and sediment transport measurements from instrumentation deployed during a 54-day winter period at two sites on the Louisiana inner shelf are presented. Strong extratropical storms, with wind speeds of 7.8 to 15.1 m s-1, were the dominant forcing mechanism during the study. These typically caused mean oscillatory flows and shear velocities about 33% higher than fair weather (averaging 12.3 and 3.2 cm s-1 at the landward site, and 11.4 and 2.7 cm s-1 at the seaward site, respectively). These responses were coupled with mean near-bottom currents more than twice as strong as during fair weather (10.3 and 7.5 cm s-1 at the landward and seaward sites, respectively). These flowed in approximately the same direction as the veering wind, causing a net offshore transport of fine sand. Weak storms were responsible for little sediment transport whereas during fair weather, onshore sand transport of approximately 25-75% of the storm values appears to have occurred. This contradicts previous predictions of negligible fair-weather sediment movement on this inner shelf.  相似文献   
208.
A high-resolution seismic survey covering more than 2,000 km2 has revealed the processes responsible for the slope morphology and channel sedimentation across the forearc slope-basin of the Kurile Arc–NE Japan Arc collision zone, offshore from Tokachi (Hokkaido, Japan). The dominant slope contours parallel the trench but, in the middle and lower reaches of the southern slope, contours are convex-shaped with an offshore trend. This sector of the slope is traversed diagonally by the Hiroo submarine channel. The offshore-trending convex contours and the channel course have developed through the interplay of tectonic and sedimentary processes, including the development of anticlines, anticline-induced lobe sedimentation and channel avulsion. In its upper reaches, the channel is restricted by a topographic low associated with NNW–SSE-trending anticlines which developed within the upper and middle slope sectors during late Miocene uplift. The uplift timing and trend of these anticlines indicate that they resulted from collision, the channel sedimentology and slope morphology of the middle and lower slopes having been influenced by Pliocene uplift of NE–SW-trending anticlines. The trends of these anticlines parallel those of the Kurile Trench. The Pliocene and early Pleistocene strata of the middle and lower slopes consist of ponded lobe sediments deposited along the palaeo-Hiroo submarine channel on the landward side of the anticlines. As a lobe pile accumulated, the channel thalweg shifted to the north of the stack, allowing the channel to bypass the topographic high formed by the growing stack. Thick levee deposits built up along the channel course during the late Pleistocene and Holocene. These levees, along with the Pliocene and early Pleistocene lobes, are reflected in the present-day sigmoid-shaped, convex offshore-trending contours. Thus, the interplay of subduction- and collision-related anticlines, tectonic-related channel ponding, and avulsion has contributed to the slope morphology of the southern Kurile Trench.  相似文献   
209.
On the basis of the temperature and salinity survey data of July, 1975 and the historical da-ta of relevant hydrological and meteorological stations, this paper discusses the change patternand cause of the upwelling and its relation to the fisheries in the Southern Fujian-Taiwan ShoalFishing Ground. Being important for the benefit of fisheries, the above points have received  相似文献   
210.
应用遗传神经网格方法分析赤潮监测数据   总被引:1,自引:1,他引:1  
简要介绍了遗传神经网络方法的原理 ,探讨了应用遗传神经网络方法研究辽东湾海域丹麦细柱藻 (Leptocylindrusdanicus)赤潮与其环境因子之间的关系 ,计算了各环境因子对丹麦细柱藻赤潮的贡献。结果表明 ,温度、盐度、DIN的变化对研究海域丹麦细柱藻种群密度的增长有比较重要的影响 ,DIN是营养限制因子。遗传神经网络是分析赤潮监测数据的有效方法 ,值得进一步探索  相似文献   
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