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1.
渤海湾客滚运输业是一个高利润、高风险的行业,在其高速发展的同时,部分企业由于片面追求生产效益、市场份额,对安全生产和管理工作重视不足,自1999年至2002年间就发生了数起客滚船重、特大海难事故。  相似文献   

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高超  王辉 《世界海运》1998,21(5):24-25
本文通过实例分析了岛屿对大风浪的屏蔽效应,以及如何利用此效应进行航线的选择。  相似文献   

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台湾海峡冬季大风浪时的航法探讨技   总被引:1,自引:0,他引:1  
涂礼肃 《世界海运》2002,25(1):15-16
台湾海峡是我国南北海运的必经之道,台湾岛是我国东南沿海各港口通往太平洋各国的重要驿站,实现两岸直接“三通”,将有力地推动海峡两岸的海运事业的发展,推进两岸经济的共同繁荣。为确保航行安全,根据实践经验,提出几条在大风浪条件下主要直航航线的航法及注意事项。  相似文献   

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大风浪中船舶航行安全性评价   总被引:13,自引:1,他引:12  
从船舶在波浪中运动的机理出发,将模糊数学中的层次分析法理论用到大风浪中船舶航行安全性评估上来,开发了相应的计算程序。寻找到了船舶在波浪中航行时的安全航态范围和在某一航速(或航向)时的最佳航向(或航速),形成了一套“理论航法”,使得驾驶员在操纵船舶时能够得到有效的指导。  相似文献   

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熊建国 《天津航海》1999,(3):8-10,15
本文扼要介绍了通过麦哲伦海峡的体会,海峡当局的有关规定,强制和非强制引航段的航法,对首次过海峡的船长,有较实际的参考价值。  相似文献   

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牛国臣 《天津航海》2002,(3):13-15,27
本文就关门海峡的航道,潮流,信号,通航情况,航法及船过海峡时应注意的问题进行了论述,并浅谈了自己几次通过关门海峡的体会。  相似文献   

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郝安临 《世界海运》1998,21(2):16-17
朝鲜半岛南部水域的通航及航道概况,航线的选择,航法及其在该水域航行中的安全措施和注意事项。  相似文献   

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根据湖区的现场观测资料,利用数理统计和理论分析相结合的方法,探讨了湖区的波高和波周期的一元和二元联合分布,并给出了该湖区波浪的各种统计特征值,提出了波高、波周期和两者联合分布的经验分布模式。该公式为确定湖区风浪统计特征值提供依据和参考。  相似文献   

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通过大连太平湾海岸动力地貌调查,分析研究了厂址及周边海岸冲刷、堆积等不同地貌形态特征、岸线冲蚀形态、水下沉积物分布特征。分析结果表明,该区海岸岬角处表现为冲刷,海蚀地貌发育,海蚀柱、海蚀崖与海蚀平台发育较为典型,岬湾处海滩呈微淤状,岸滩宽度较大,沉积物中以粗中砂所占的比例最大,并显示北粗南细的格局。太平湾附近海岸进行了大面积的近岸围海养殖工程,目前仍有岸段养参池石堤向海推进,其规模和占海面积均较大,海岸变化幅度较为显著。  相似文献   

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基于钱塘江河口特殊的自然特征,自20世纪60年代开始,钱塘江河口进行了大范围的治江围涂。由MIKE软件建立了杭州湾水动力水质模型,探讨钱塘江河口围涂工程对杭州湾潮流场、盐度场以及水质的影响。研究结果表明,仅在工程区域附近影响了杭州湾水域的水动力特征,使得河口区的流速增大;围涂工程使得湾内盐度等值线后退,有效地减弱了杭州湾的盐水入侵;工程后随钱塘江而来的污染物得到了更快的扩散稀释,减弱了河口区水体的污染。  相似文献   

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本文基于三体风电运维船船型,结合M型船的特征要素设计改造出M型风电运维船。利用数值仿真技术模拟出M型风电运维船波浪航行时的波浪增阻与纵摇、垂荡情况,将数值仿真计算结果与原三体船的试验数据进行比较,以此探索不同M型船船型对船舶波浪航行时的波浪增阻与纵摇、垂荡情况的影响。最终确定了耐波性能较优的船型方案,从而为M型风电运维船船型设计提供了一定的参考和借鉴。  相似文献   

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The dissolved lead was studied in the whole salinity gradient of the system composed of the Loire estuary and the North Biscay continental shelf. About 130 samples were collected in winter 2001 and spring 2002 during Nutrigas and Gasprod campaigns (Programme PNEC-Golfe de Gascogne, RV Thalassa) and metal measurements were conducted on board by Potentiometric Stripping Analysis. In the Loire estuary, levels of dissolved lead ranged from 0.15 to 0.24 nM and from 0.04 to 0.26 nM in winter and spring, respectively. Compared to the concentrations reported in 1987 and 1990 (0.4–1.7 nM; Boutier, B., Chiffoleau, J.F., Auger, D., Truquet, I., 1993. Influence of the Loire river on dissolved lead and cadmium concentrations in coastal waters of Brittany. Estuar. Coast. Shelf S., 36:133–143, Estuarine, Coastal and Shelf Science 36, 133–143) our study indicated much lower values. The fall in concentration in the estuary could be attributed to the stopping of activity of Octel, a big manufacturer of tetra alkyl lead. Discharge in dissolved metal to the continental shelf by the Loire river was assessed as 7.5 and 1.9 kg day− 1 for winter and spring, respectively. On the continental shelf, levels of dissolved lead varied within 0.06 and 0.27 nM in winter (0.15 ± 0.06 nM, sd = 1.96, n = 49), whereas concentrations measured in spring were in the range 0.06–0.17 nM (0.09 ± 0.03 nM, sd = 1.96, n = 60). This difference in metal concentration was related to the amounts of rainfall that have fallen over the continental shelf: estimations of inputs by this way (74 and 32 kg day− 1 in winter and spring, respectively) appeared to be significantly higher than inputs from the Loire river (7.5 and 1.9 kg day− 1 in winter and spring, respectively). The distributions of dissolved metal in the surface waters highlighted the role of suspended particular matter (SPM) for a rapid “trapping” of lead near the mouth of the estuary. The vertical distributions showed, in the stratified area, a biological transfer of lead between winter and spring from surface waters to the halocline.  相似文献   

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尽管线性波浪理论不适宜应用在近岸浅水海域,但我国《海港水文规范》中波浪浅水变形的计算方法仍是建立在线性波浪理论的基础上,且没有考虑外界因素(如风和海底摩擦)的影响。为弥补上述不足,基于波浪传播过程中能量守恒的原理建立了一个波浪浅水变形的数值模型,该模型采用椭圆余弦波假定,并考虑了风和海底摩擦对波能的增加和损耗作用。在该数值模型基础上,分析大量工况下的计算结果,提出了便于工程设计初期用于确定近岸波浪要素的浅水变形实用计算方法(PCM)  相似文献   

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Seasonal variations in nutrient inputs are described for the main rivers (Loire and Vilaine) flowing into the northern Bay of Biscay. The river plumes are high in N/P ratio in late winter and spring, but not in the inner plume during the summer. Conservative behavior results in most nutrients entering the estuary and eventually reaching the coastal zone. Temporal and spatial aspects of phytoplankton growth and nutrient uptake in the northern Bay of Biscay distinguish the central area of salinity 34 from the plume area. The first diatom bloom appears offshore in late winter, at the edge of the river plumes, taking advantage of haline stratification and anticyclonic “weather windows.” In spring, when the central area of the northern shelf is phosphorus-limited, small cells predominate in the phytoplankton community and compete with bacteria for both mineral and organic phosphorus. At that period, river plumes are less extensive than in winter, but local nutrient enrichment at the river mouth allows diatom growth. In summer, phytoplankton become nitrogen-limited in the river plumes; the central area of the shelf is occupied by small forms of phytoplankton, which are located on the thermocline and use predominantly regenerated nutrients.  相似文献   

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在全面分析风浪流对绞吸船定位桩的冲击荷载的基础上,对绞吸船施工中定位桩的动力响应提出了编程计算和有限元分析相结合的研究方法,即:通过编写程序计算定位桩在各种风浪流条件下的环境荷载,通过有限元模拟求解出定位桩在风浪流作用下的动力响应.采用该方法得出的结果与实际较为符合,对绞吸船的安全施工具有参考价值.  相似文献   

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Seasonal changes in the abundance and biomass of cyanobacteria (Synechococcus and Prochlorococcus) and picoeukaryotes were studied by flow cytometry in the upper layers of the central Cantabrian Sea continental shelf, from April 2002 to April 2006. The study area displayed the typical hydrographic conditions of temperate coastal zones. A marked seasonality of the relative contribution of prokaryotes and eukaryotes was found. While cyanobacteria were generally more abundant for most of the year (up to 2.4 105 cells mL− 1), picoeukaryotes dominated the community (up to 104 cells mL− 1) from February to May. The disappearance of Prochlorococcus from spring through summer is likely related to shifts in the prevailing current regime. The maximum total abundance of picophytoplankton was consistently found in late summer–early autumn. Mean photic-layer picoplanktonic chlorophyll a ranged from 0.06 to 0.53 µg L− 1 with a relatively high mean contribution to total values (33 ± 2% SE), showing maxima around autumn and minima in spring. Biomass (range 0.58–40.16 mg C m− 3) was generally dominated by picoeukaryotes (mean ± SE, 4.28 ± 0.27 mg C m− 3) with an average contribution of cyanobacteria of 30 ± 2%. Different seasonality of pigment and biomass values resulted in a clear temporal pattern of picophytoplanktonic carbon to chlorophyll a ratio, which ranged from 10 (winter) to 140 (summer). This study highlights the important contribution of picoplanktonic chlorophyll a and carbon biomass in this coastal ecosystem.  相似文献   

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