预测低周疲劳寿命的一种新方法

从低周疲劳损伤可由疲劳过程中的非弹性响应来反映的理念出发,以循环弹性余应变能密度来表征循环应力应变曲线的非线性部分偏离线性的程度,建立了基于循环弹性余应变能密度为基本参量预测低周疲劳寿命的新方法。采用30CrNiMo8钢的疲劳试验结果和文献中对某高温合金的疲劳试验结果,对该预测模型的预测结果和Manson-Coffin公式、三参数幂函数模型预测结果进行了对比分析,结果表明,文中提出的预测模型的预测结果与试验结果吻合良好,预测精度高于Manson-Coffin公式的预测精度,并接近或高于三参数幂函数模型的预测精度。     

预测低周疲劳寿命的一种新方法

从低周疲劳损伤可由疲劳过程中的非弹性响应来反映的理念出发,以循环弹性余应变能密度来表征循环应力应变曲线的非线性部分偏离线性的程度,建立了基于循环弹性余应变能密度为基本参量预测低周疲劳寿命的新方法.采用30CrNiM08钢的疲劳试验结果和文献中对某高温合金的疲劳试验结果,对该预测模型的预测结果和Manson-Coffin公式、三参数幂函数模型预测结果进行了对比分析,结果表明,文中提出的预测模型的预测结果与试验结果吻合良好,预测精度高于Manson-Coffin公式的预测精度,并接近或高于三参数幂函数模型的预测精度.     

船检质量体系对船舶寿命周期质量控制的作用

介绍了南京地区船舶行业质量体系建立和运行的现状,对实施过程中的问题进行了分析并提出了建议。本文分析了如何应用船检质量管理体系自我完善功能对“船舶寿命周期质量”进行控制,切实提高船舶质量,并且使船舶行业的质量管理体系向更加规范、更加完善的方向发展。     

Inland transportation system planning by life cycle impact assessment: a case study

The comparison of land and inland water transportation from economical and ecological points of view is discussed. Required freight rates for trucks and ships are calculated and compared to find which has economic superiority. From the environmental impacts of these two transportation types, the comparative environmental destruction indices for two different time-durations are estimated. All these investigations were conducted for the Yokohama–Fukuoka route in Japan. Life cycle impact assessment, a very useful tool for quantitatively evaluating the environmental influence of a product, was used to compare the environmental burden imposed by these types of transportation. Finally, the way that these results can be used for inland transportation system planning is discussed. Received: January 21, 2000 / Accepted: June 27, 2000     

The econometric testing of investment incentives: A cointegrated approach

Thie paper re-examines the link between shipping investment and investment incentives, first explored in this journal by Marlow, and subsequently developed by mcWilliams et al. in the July-September issue. Examination of the ststistical properties of the data reveals that some of McWilliams' results may be flawed. A modified version of the Marlow model is estimated. checking for statistical and economic consistency, using cointegration, checking for statistical and economic consistency, using cointegration techniques. The estimated model resolves marlow's original challenge, but does not appear to be as robust as could be wished.     

The econometric testing of investment incentives: A cointegrated approach

Thie paper re-examines the link between shipping investment and investment incentives, first explored in this journal by Marlow, and subsequently developed by mcWilliams et al. in the July–September issue. Examination of the ststistical properties of the data reveals that some of McWilliams' results may be flawed. A modified version of the Marlow model is estimated. checking for statistical and economic consistency, using cointegration, checking for statistical and economic consistency, using cointegration techniques. The estimated model resolves marlow's original challenge, but does not appear to be as robust as could be wished.     

Deregulation policy and revitalization of Singapore's bunker supply industry: An appraisal

High bunkering standards are important for ship operators and port authorities for a variety of reasons. When problems arise they may have serious consequences for a port's image. Faced with a range of difficulties, since 1985 Singapore has attempted to revitalize and modernize its bunkering industry, deploying market deregulation to raise service quality and expand consumption. This policy is assessed in terms of its quantitative and qualitative consequences, and as an example of the outcomes of deregulation. Early price reductions achieved substantial market growth, but low-cost bunkering has more recently been significant as a counterbalance to new quality problems generated by unsupervized competition. These have necessitated substantial policy responses in the 1990s which are only now overcoming the setbacks caused by the unregulated market.     

半潜式平台关键结构全寿期极限强度预报方法研究

文章基于逐步破坏分析法和有限元计算方法,发展了一种计及材料腐蚀、疲劳裂纹等结构损伤的半潜式海洋平台关键结构全寿期极限强度计算方法。以一服役水深为3000 m半潜式平台为研究对象,选取横撑和立柱局部结构作为研究对象,以不同服役年限下裂纹扩展长度和腐蚀厚度作为变化参数,采用ANSYS软件建立其参数化有限元模型,计算了不同服役年限下半潜式海洋平台关键结构极限强度,在此基础上分析了全寿期内关键结构极限强度随服役年限的变化规律。     

珍爱生命:关注青少年的生命教育

生命是可贵的且具有不可逆性,关注生命和生命价值是教育的终极目标之一。青少年作为一个特殊的群体,忽视生命教育将会给他们和社会带来不可估量的损失。因此,青少年的生命教育成为又一个关注点。文中分析了造成青少年生命教育缺失的原因,并论述了生命教育的目的与内涵。     

港口与海岸工程结构全生命周期概率设计

在港口与海岸工程结构整个生命期内,环境条件和结构系统的状态均会随时间发生变化。结构系统状态变化主要包括:由环境条件作用产生的结构累积损伤(或变形或位移)、钢或钢筋混凝土构件锈蚀、地基冲刷或淤积、地基物理力学指标降低或提高等。文中提出了考虑整个生命周期内环境条件和结构系统状态变化的工程结构全寿命周期概率设计的概念,并结合沉箱式防波堤在长期波浪作用下累积滑移概率分析和考虑钢筋混凝土结构构件抗力随时间变化的钢筋混凝土结构可靠度分析,在工程结构全寿命周期概率设计理论方面进行了初步探讨,为该课题的深入研究提供参考。     

The social psychological consequence of a life at sea: A causal model

This paper explores the influence of this occupation on alienation and social integration of its members. Data were collected using a survey instrument from a sample of 293 seamen, both officers and crew. Factors determining variance in levels of alienation are examined using multiple regression technique. Results indicate that variance in several occupational features of life at sea affect the degree of alienation experienced by seamen, and a number of social characteristics were found to mitigate these influences. Supplementary qualitative data are also used.     

美国的绿色港口之路

美国各大港口正面临着巨大的塞港压力,必须迅速发展以满足当前及未来的贸易需求。由于多数港口在市区,空气和水质问题使得港口运作和扩建变得越来越复杂。美国各港口应对这一挑战的办法是把环保理念纳入到日常运作和对未来码头的设计和建设中去。这不仅来自联邦政府、各州政府、环保部门和环保社团日益加大力度的监管,而且也来自各港口本身,港口要求自己管理环保。     

The development of the TIGRIS XL model: A bottom-up approach to transport, land-use and the economy

The project appraisal method in the Netherlands distinguishes direct effects, indirect distribution effects and indirect generative effects. Transport models are generally available for calculating the benefits of transport projects to travellers as part of the direct effects. The TIGRIS XL model, a Land-Use and Transport Interaction model, adds indirect distribution effects for the housing and labour market, by modelling changes in the spatial distribution of jobs and residents. This paper describes the current TIGRIS XL model and how it can be applied in the evaluation of transport projects. It refers to work done with the TIGRIS XL model to improve the calculation of the direct benefits by applying the so-called ‘logsum’ method. Finally it discusses ideas on how to extend the TIGRIS XL model to address indirect generative effects as well.The current TIGRIS XL model, its integration with the National Model System (the standard tool for the Dutch government to analyse the effects on passenger transport) and basic design principles are the starting point of such an exploration. These design principles include:

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an emphasis on detail, both spatial as well as in socio-economic segments, to account for differences in the availability of choice alternatives and in choice behaviour, and to provide impacts by region and socio-economic group;

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the requirement that the relationships used rest on an empirical foundation.

The post-processing methods proposed on this paper for the calculation of the direct benefits and indirect generative effects are consistent with these design principles. To calculate the indirect generative effects, a post-processing module is proposed which transforms changes in travel times and land-use into agglomeration effects. These agglomeration effects combine several of the generative effects, like scale economies, an increasing variety of products, labour market matches and knowledge spill-over. The effects of changes in the agglomeration indicator on productivity can be estimated with existing data sources, as was demonstrated in the UK (Graham, 2005).     

The urban port: A hidden resource for the city and the coastal zone

Abstract

This paper is concerned with the changing pattern of activity on the urban waterfront. It examines developments in marine transportation technology and in the economic structure of the central city that have influenced the function of the urban port. Drawing upon data related to the West Side of Manhattan, the impact of the changes in cargo and passenger ship operations on the urban port is described and analyzed. A twofold strategy for public agencies to identify and understand the opportunities presented by technological change and to formulate policies for the redevelopment of the urban coastal zone is discussed.     

Port concentration, inter-port competition and revitalization: the case of Mombasa, Kenya

Mombasa is overwhelmingly the dominant port, urban and industrial complex on the Kenya coast. Improvements in operational efficiency, management restructuring and the revitalization of the port in the competitive context of the East A frican port system as a whole are critically important current policy objectives. These issues are discussed in the context of the character and development of the port. Two further issues are outlined: the proposal to establish a free port at Mombasa, and the idea of developing a second deepwater port elsewhere on the Kenya coast. Both are considered interesting but premature.     

A portfolio approach to strategic chartering decisions

Modern management techniques are slowly but surely being introduced aslo in shipping management. Large sections of the industry practises strategic management at various levels in the firm. This paper outlines a method for deciding chartering strategies in the international bulk shipping industry. A well known risk/return model is tailored to transportation contracts in the shipping industry. The model delineates a set of optimally defined transportation contracts that may serve as a basis for the shipowner's strategic decisions. The strategies and elements of strategies suggested by the model have historically been practised by a number of successful shipowners. An important conclusion of the paper is that no second best problems exists and hence movement towarts the optimal solution is advocated even if such a solution cannot or will not be reached. Additionally, the paper provides an organized way of crafting, analysing and applying chartering strategies where the outcomes can be clearly defined and analysed based on well known statistical concepts and theories.     

一种基于经济寿命理论的船闸大修周期确定方法

船闸大修周期的确定是船闸管理工作的重点,目前我国在这方面没有统一规定.将技术经济学中设备经济寿命的概念引入船闸大修周期的确定过程,使船闸的大修更加经济合理,为船闸大修计划的制定提供了新的思路,改变各船闸根据经验或是大修工程审批情况制定大修计划、船闸带病运行的现状.     

Shorelines management: The French approach

Although France does not have a specific law dealing with shorelines management, various policies and policy instruments exist which enable a certain amount of control over the shoreline development process. This article discusses the various institutional arrangements in France as they relate to (1) problems of marine pollution, (2) the control of land‐based pressures for shoreline use and development, and (3) the creation of a new shorelands trust. The role of existing institutions, such as the six river basin agencies, is also discussed.     

焊接结构多轴疲劳寿命预测结构应力法

海洋工程焊接结构形式复杂且遭受随机波浪载荷作用,焊接接头多数处于多轴疲劳状态,而目前工程上主要采用基于单轴疲劳理论和试验的方法预测结构的疲劳寿命。为了提高焊接结构疲劳寿命预测的准确性,文章提出了一种评估焊接接头疲劳强度的新型结构应力法,并与临界面理论相结合,能够用于实际焊接结构的多轴疲劳寿命预测。通过对国际上已公开发表的疲劳试验数据进行有限元分析,证明了文中提出的结构应力法比传统的热点应力法具有更高的精度,以及该方法应用于焊接结构多轴疲劳寿命预测的可行性。最后,应用该方法对一个T型管节点进行了多轴疲劳寿命计算。     

他属于那一片蔚蓝

“如果有一天小女儿问我,爸爸去哪里了？我会告诉她,你爸爸是属于大海的,有海的地方就有你爸爸。”他的妻子这样说。是的,他属于大海,属于他热爱了一生、深深眷恋的那一片蔚蓝。现在他融入了那一片蔚蓝,永远地与祖国的蓝色疆土为伴。阳光下,浪花熠熠生辉,奔腾着,跳跃着,急切地想要向我们倾诉,他是怎样一个人。