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971.
随着开发形势的发展,流花油田“南海挑战号”半潜平台现有的4台发电机越来越不满足电力供应要求,因而必须增加新的发电机。但由于增加电机及相应辅机、结构等较重,超过规范要求。“南海挑战号”必须停产做倾斜试验,这会对业主造成很大的经济损失。针对电站扩容项目,通过数值计算方法精确得到平台改造后的重量重心,平台完整稳性和破舱稳性均满足船级社规范中关于稳性的要求,避免了停产做倾斜试验等问题。 相似文献
972.
这是作者 2 0 0 1年在香港举行的TOC亚洲会议上所作的关于集装箱港口发展自动化的报告 ,重点回答了中小集装箱码头要不要发展自动化以及如何实现自动化的问题 ,提出了发展中小集装箱码头自动化的思路和新的方案 ,并对采用自动化技术后所带来的投资效益进行了较深入的分析和评价 相似文献
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974.
Quantitative estimation of the influence of surface thermal fronts over chlorophyll concentration at the Patagonian shelf 总被引:1,自引:0,他引:1
Andrs L. Rivas 《Journal of Marine Systems》2006,63(3-4):183-190
Eighteen-year (1985–2002) mean monthly SST Pathfinder data with 9 km spatial resolution have been used to estimate surface gradients by finite differences. Then the seasonal climatological means have been calculated from the intensity of these gradients, and surface thermal fronts present in the Patagonian Continental Shelf (PCS) have been located. Moreover, 6 years (1998–2003) of SeaWiFS data with approximately 4 km spatial resolution have been used to estimate monthly composite images of surface chlorophyll concentration, after which seasonal climatological means distributions have been generated. Both seasonal distributions have been analyzed together and by combining the knowledge of oceanographic processes and phytoplankton responses to light and nutrient availability, regions where the presence of a thermal front affects photosynthetic activity have been identified. Subjective criteria have been applied to define eighteen areas where phytoplankton biomass is influenced by the presence of a thermal front. In these areas, the surface chlorophyll (spatial mean and total), its relationship with the surface chlorophyll of the whole region, and the seasonal evolution of this relationship have been calculated. All frontal areas cover less than 15% of the total surface, but they contribute with over 23% of the phytoplankton annual mean biomass. Considered as a group, during summer they show high chlorophyll values very similar to those in spring. During the cold period, when the water column is vertically mixed in practically the whole of PCS, the influence of physical fronts over the biological production is minimum. The frontal zone image remains clearly defined during summer, when approximately 85% of the area will have a determined mean chlorophyll concentration, while the other 15% has a 2.45 times larger value. While three pattern trends have been identified in the frontal areas, only two of them condition the pattern of the group, due to their horizontal extension. 相似文献
975.
JAMES S. WEBSTER HOWARD FIREMAN DILLON A. ALLEN ADRIAN J. MACKENNA JOHN C. HOOTMAN 《Naval Engineers Journal》2007,119(2):35-48
The US Navy has been studying the technical and cost impacts associated with the availability and cost of fossil fuel contrasted with nuclear energy alternatives for surface combatants and amphibious warfare ships. Over the past 2 years these efforts have grown in maturity to examine the tactical and strategic implications of our Navy's dependence on fossil fuels from technical, economic, and military perspectives. This paper will present three major topics:
Given the US Navy's dependence on fossil fuels and the expected increase in cost and reduced availability of fossil fuel, propulsion system investment decisions made today will have a profound impact on the future tactical and strategic roles of the US Navy surface fleet. This paper lays the foundation for providing robust and flexible technology decision opportunities for the Navy's future. 相似文献
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Background research on alternative energy sources.
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A survey discussion of current and future power and propulsion system technologies.
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An overview of principal Naval Sea Systems Command studies on the integration of alternative power and propulsion system technologies into notional surface combatants, submarines, and amphibious warfare ships.
Given the US Navy's dependence on fossil fuels and the expected increase in cost and reduced availability of fossil fuel, propulsion system investment decisions made today will have a profound impact on the future tactical and strategic roles of the US Navy surface fleet. This paper lays the foundation for providing robust and flexible technology decision opportunities for the Navy's future. 相似文献
976.
This paper quantifies the potential environmental benefit of short sea shipping. Critical strategic issues relevant to formulating
public policy are developed. Coastal shipping has traditionally been a major sector of the maritime industry. This continues
to be the case in the European Union, but the sector has diminished in relative importance in North America as the transport
industry has become increasingly dominated by less environmentally-friendly interstate trucking and railroads. Congestion
threatens to overwhelm overland carriage and limit economic growth. An alternative strategy is to revitalize coastal shipping
as short sea shipping to alleviate traffic congestion and enhance economic development by maintaining freight flow efficiency.
Because ship transport offers higher fuel economy and lower emission of harmful pollutants, the environmental benefits of
short sea shipping over land transportation can be quantified and used to inform public policy. 相似文献
977.
在九月召开的国际航空货运协会世界航空货运论坛上&;#183;波音公司发布了其两年一度的世界航空货运预测报告,其中鲜有特别的内容。 相似文献
978.
979.
980.
本文通过实际案例阐述了在我国目前公路建设广泛开展建设——经营——转让 (BOT)条件下 ,中国铁路工程总公司以限定概算、总额包干的建设项目管理承包 (PMC)模式 ,参与公路工程建设的实践 相似文献