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渤海是我国最大的内海,地理位置十分重要,但海域中的沉船给通航安全和海洋环境安全带来了重大影响,据统计,目前渤海海域共有沉船73艘,部分沉船在低潮时甚至会露出水面。为保障通航安全,保护好渤海,使其成为清洁海湾,由国家财政出资、交通运输部牵头,部海事局组织实施对渤海湾“碧海行动”为题的沉船打捞计划。 相似文献
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港口航道中的沉船对于港口疏浚施工和运营有着不言而喻的巨大影响,在设备资源有限及为节约成本的前提条件下,探索一种简便拖带沉船的方法就很具有必要性.本文主要介绍如何利用改造后的水囊加压产生浮力将沉船带离海床拖至指定位置的过程及方法. 相似文献
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福建泉州港肖厝作业区4号泊位工程施工过程中,“福达”轮沉船打捞为我公司首次对大型沉船进行打捞施工。本文详细介绍含重油沉船的水下切割施工。 相似文献
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12月22日,举世瞩目的宋代古沉船“南海一号”出水!同时,“南海一号”整体打捞起浮仪式在肩负起浮重任的亚洲第一浮吊“华天龙”号上隆重举行。交通部副部长徐祖远出席了仪式并致辞。 相似文献
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刚刚过去的2002年,在航海史学界发生一件震惊世界却又争议颇多的新闻:英国人加文·孟席斯提出一个新理论:中国明朝郑和率领的船队比哥伦布早72年发现新大陆,比麦哲伦先100年绕行世界一周,比达伽马领先一步到达印度,比库克早到澳洲,航线一度延伸到了南极,即"郑和最早发现美洲新大陆后最先实现环绕地球航行". 相似文献
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The Great Barrier Reef (GBR), Australia, is managed under the GBR Marine Park Act (1975) and is seen as a shining example of marine resource management. The principle tool of management is zoning for multiple use. We examined surveillance and illegal fishing around two inshore islands (Magnetic and Orpheus) of the GBR Marine Park in 2000/2001. Both islands are near Townsville, the largest city adjacent to the GBR. Surveillance effort was low, with vessels present on only 16% of days of the year. Measurable but low levels of illegal recreational fishing occurred within no-take zones. Levels decreased with increasing surveillance effort. Thus zoning was not completely successful in protecting fish targeted by fisheries, even within the most highly enforced sections of the Park. The expansion of no-take zones in 2004 from 4.6% to 33.4% of the area of the 358,000 km2 Park represents a considerable challenge for future surveillance and enforcement. 相似文献
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Measurements of turbulence were performed in four frontal locations near the mouths of Block Island Sound (BIS) and Long Island Sound (LIS). These measurements extend from the offshore front associated with BIS and Mid-Atlantic Bight Shelf water, to the onshore fronts near the Montauk Point (MK) headland, and the Connecticut River plume front. The latter feature is closely associated with the major fresh water input to LIS. Turbulent kinetic energy (TKE) dissipation rate, ε, was obtained using shear probes mounted on an autonomous underwater vehicle. Offshore, the BIS estuarine outflow front showed, during spring season and ebb tide, maximum TKE dissipation rate, ε, estimates of order 10− 5 W/kg, with background values of order 10− 6 to 10− 9 W/kg. Edwards et al. [Edwards, C.A., Fake, T.A., and Bogden, P.S., 2004a. Spring–summer frontogenesis at the mouth of Block Island Sound: 1. A numerical investigation into tidal and buoyancy-forced motion. Journal of Geophysical Research 109 (C12021), doi:10.1029/2003JC002132.] model this front as the boundary of a tidally driven, baroclinically adjusted BIS flow around the MK headland eddy. At the entrance to BIS, near MK, two additional fronts are observed, one of which was over sand waves. For the headland site front east of MK, without sand waves, during ebb tide, ε estimates of 10− 5 to 10− 6 W/kg were observed. The model shows that this front is at the northern end of an anti-cyclonic headland eddy, and within a region of strong tidal mixing. For the headland site front further northeast over sand waves, maximum ε estimates were of order 10− 4 W/kg within a background of order 10− 7–10− 6 W/kg. From the model, this front is at the northeastern edge of the anti-cyclonic headland eddy and within the tidal mixing zone. For the Connecticut River plume front, a surface trapped plume, during ebb tide, maximum ε estimates of 10− 5 W/kg were obtained, within a background of 10− 6 to 10− 8 W/kg. Of all four fronts, the river plume front has the largest finescale mean-square shear, S2 ~ 0.15 s− 2. All of the frontal locations had local values of the buoyancy Reynolds number indicating strong isotropic turbulence at the dissipation scales. Local values of the Froude number indicated shear instability in all of the fronts. 相似文献
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基于势流假设,建立气泡与壁面耦合数值模型,运用边界积分法求解,开发了三维计算程序,计算值与实验值吻合良好。从气泡与壁面相互作用的基本现象入手,基于开发的程序系统地研究了刚性壁面附近气泡的动力学特性,其中包括水平壁面及倾斜壁面。研究壁面的Bjerknes效应与各特征参数之间的关系,并将各种工况的计算结果与基于Kelvin—impulse理论的Blake准则进行对比分析及讨论,得出偏射流方向及壁面压力与气泡的特征参数的密切关系,同时给出了Blake准则的适用范围。旨在为相关的近壁面气泡动态特性研究提供参考。 相似文献
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基于对真空断路器凸轮操作机构的分析,建立了相应的数学模型,并通过所建立的模型,对凸轮机构进行了优化设计。结果表明,所建立的数学模型为真空断路器凸轮操作机构提供了一种有效的优化设计方法。 相似文献
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本文介绍了几种典型的直流固态断路器拓扑结构,总结了各自的特点,分析了直流固态断路器的应用前景,最后设计了1500V/4000A原理样机的相关参数,并给出了样机分断仿真研究结果。 相似文献
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介绍了可倒翻碟簧的负刚度特性,总结了可倒翻碟簧的设计方法及制造工艺注意事项,并以在断路器中的应用为例,设计了几组可倒翻碟簧,并对结果进行了分析. 相似文献
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2003年10月27日,中远集团首批通过保安规则(ISPS规则)审核船舶颁证仪式在北京举行,中国海事局、中国船级社(CCS)、香港海事处有关领导出席了此交电视电话会议,经中国海事局授权,中远船级社在经过严格审核程序后,向中远集道“商城”轮,中远(香港)航运公司“鹏图”轮,中远航运集运“清江”轮代表颁发了国际船舶保安证书。中远船舶获此证书在国内尚属首次,这也标志着我国航运界在推进和实施ISPS工作上取得了突破性进展。 相似文献