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水上漂流是近年来兴起并发展起来的一项水上活动.由于漂流安全管理法规不健全甚至仍处于空白,致使某些地方的漂流活动处于失控失管状态. 相似文献
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随着旅游业的发展,水上漂流项目在各地迅速开展起来。本文介绍了东北地区漂流总体情况以及漂流筏检验现状,并针对东北地区的实际情况与特点,提出一些地区性检验法规建设的建议。 相似文献
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随着旅游市场的不断开放,旅游方式呈多元化方向发展。桂林至阳朔的漓江航线是一条闻名遐迩的旅游"黄金水道"。这里有着"桂林山水甲天下"的精华景致,随之也形成了以排筏、水上漂流等为游览工具的游览模式。由于乘坐排筏游览的方式亲近自然且航线机动灵活,排筏的数 相似文献
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随着市场经济的发展,贵州省水上交通安全的监管范围和对象发生了变化:一是通航水域不断拓展,航道里程比“八五”期增加了200多公里;从事旅游的湖泊、水库增多,新开辟了水上漂流活动,漂流航道达到200多公里。二是船舶由小吨位、非机动向大吨位、大功率船舶发展。三是专业水运企业的运力份额在下降,个体运力显著增加。四是船舶种类日趋多样化。…… 相似文献
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法律术语的翻译必须依托法律传统,而法律渊源无疑是其所含概念最具权威性的出处。本文将借助“Principal”与“主犯”这对近似法律术语,从法律渊源角度,运用认知语言理论,研究英汉法律术语的互译。 相似文献
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在8级大风中安全接送8艘进出口船舶,快速、灵活、平稳、安全的特性和对各种船型的适用性受到引航员和外轮船长的高度赞扬。因深水航槽延伸,引航作业区外移,上海港长江口6级以上大风不能接送引航员的禁区从此被打破…… 相似文献
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企业档案是指企业在生产经营和管理活动中形成的对国家、社会和企业有保存价值的各种形式的文件材料,它是一种无形资产,是企业的宝贵财富,它反映了企业的发展进程,记述了企业经营、管理、 相似文献
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An investigation of the drift velocity induced by water waves of a contminated surface layer is carried out. The theoretical analysis is based on a thin boundary layer on the free surface. The results of the analysis reveal that the drift velocity of a viscous layer on the water surface is 7/4 times the Stokes prediction ofc(ak)
2 wherec is the wave celerity andak the wave slope. The present experimental investigation confirms the validity of the theoretical prediction for the drift velocity for a lightly contaminated surface layer; however, for a heavily contaminated surface layer, the experimental results exceed the theoretical prediction. An investigation for a heavily contaminated layer is carried out assuming an inextensible surface layer. Thus, in the experiment, vinyl sheets are used to substitute the contaminated layers. By balancing the wave-induced mean thrust force with the mean drag force, the drift velocity is obtained and compared with the experimental results. Based on the theoretical and experimental analyses, formulae for predicting the drift velocities for laminar and turbulent flow conditions are proposed. 相似文献
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浅水中的斜航船舶受到浅水阻塞效应和不对称流的综合影响。为预报该运动中的船舶水动力,文章采用基于定常雷诺平均纳维—斯托克斯方程的计算流体动力学方法,对浅水中做斜航运动的船舶粘性绕流场进行数值模拟。考虑低航速运动的特点,忽略航速影响下的自由面兴波,由数值计算得到水动力系数在漂角影响下的变化规律。针对计算精度问题,在数值模拟中从验证和确认角度分析和评估计算结果:通过网格收敛性分析分析数值误差与不确定度;结合试验数据考察计算模型的误差。此外,从计算区域尺度、湍流模型、边界条件、船体下沉和纵倾作用方面对模型误差的影响因素进行探讨,可为改进计算模型、提高数值模拟精度提供参考依据。 相似文献
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The wrack or the ship out of control will drift with flow.One of the most important factors that drive the ship is flow current which moves circularly in tidal area.The wrack from same place always drifts in different ways if the start time is different.So,during the ship drifting period,the drift trace is also determined by both wave and wind forces.The drift direction is limited by water depth which must be deeper than ship draft. These marine structures that can not afford the hit of wrack or will destroy the wrack must be well considered when they are placed near harbor and waterway or other water area with ship running.The risk zone should be consulted according to tide and weather conditions to protect structures and ships in necessary.A method is presented here to simulate the risk zone by 2D numerical hydraulic model with tidal current,wave,wind and water depth considered.This model can be used to built early-warning and protect system for special marine structure. 相似文献
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通过水上半浮体漂移过程的模拟研究,总结出一种循其轨迹,寻其“源头”的模拟计算方法。首先分析外海流系,沿岸流系,风海流、潮流,并以数学方程式描述之,然后作半浮体漂移的推算,最后以实例验证。本研究可给海事查证工作作参考。 相似文献
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利用海洋工程水动力分析软件AQWA对一种新型无尾翼滑翔圆碟的水面漂移特性进行研究。在规则波浪条件下,对滑翔圆碟的波浪载荷、附加质量系数、运动响应幅值算子(RAOs)及水面漂移轨迹进行预报。最后,利用Matlab对波浪载荷数据进行拟合,得到在常见波频范围内、不同浪向角作用下,滑翔圆碟波浪载荷的表达式。研究结果表明,在常见波频范围内,滑翔圆碟的RAOs值及水面漂移轨迹较为合理,拥有较稳定的工作性能;拟合得到的波浪载荷表达式拥有较高精度,基本满足实际的工程计算需求,为滑翔圆碟水面漂移特性的研究工作提供一种新思路。 相似文献
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通过对潜体近水面航行波浪力作用下非线性运动响应进行建模和计算,揭示了由于二阶波浪力民低速时潜艇操纵面舵力之不足,潜体的定深控制可能难于实现,产生逐渐上浮与露出波面的非线性现象。计算结果与自由自航模的试验结果相当吻合。 相似文献
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A complete theory to obtain semianalytical solutions of the wave drift damping for a circular cylinder freely oscillating
in waves is developed. The wave drift damping can be significantly increased by heave and pitch motions. Effects of the draft
of the cylinder and effects of the water depth are shown. The effective evaluation of the free-surface integral and the corner
problem are also discussed, and the computed results of the far and near field formulations are compared. These semianalytical
solutions may prove to be important in providing validation of results obtained by numerical techniques such as the higher-order
boundary element method. 相似文献