影响钢轨滚动接触疲劳的货车参数研究

在通常曲线轨道条件下,货车车轮和钢轨之间的导向力将导致钢轨滚动接触疲劳(RCF),本文对影响钢轨RCF的有关各种货车参数进行了参数化研究。仿真模型中考虑了3种货车悬挂系统、400m~10000m半径的曲线。研究结果表明,有的参数对RCF影响十分显著,有的参数则没有影响或影响甚微。     

The potential for British coastal shipping in a multimodal chain

A strategy to revitalize coastal shipping within Great Britain is investigated. An examination of the regulatory environment shows government, at both the EU and British levels, aware of the environmental benefits of coastal shipping compared to road freight transport, if only mildly supportive in tangible terms. The geography of Great Britain and the modern preference for just-in-time deliveries have severely restricted the ability of coastal shipping to compete effectively with road freight transport. The primary objective of the paper is to investigate whether coastal shipping could be integrated into a multimodal door-to-door supply chain, where it is currently hampered by high costs of transhipment, slow transport speeds, and the incongruity of load sizes between land and sea modes. Integration requires the co-operation of all organizations within the multi-modal supply chain. However, coastal shipping companies have been known to be individualistic and mistrusting of alliances. Therefore, a Delphi study is undertaken to investigate the standpoint of leading managers in such companies towards multimodal integration. The results of the Delphi study indicate that managers are in favour of multimodal developments, in particular cooperation between coastal shipping and road haulage. However, there was agreement that the business is highly competitive, and this may prevent the forms of collaboration required for multimodal systems. The secretive nature of the coastal shipping sector could impede joint marketing to promote a mode of transport that is often 'invisible' to shippers. There was little consensus on the relationship that should exist between coastal shipping and ports, a topic worthy of further investigation.     

ESI,专业化的虚拟仿真技术推动数字化造船

在工程仿真领域,有一家以提供专业化的仿真解决方案享誉业界的公司引起了记者的注意,这家公司何以能在激烈的全球CAE行业中赢得越来越多的市场?其解决方案的特点是什么?其未来发展和技术研发方向是什么?面对中国技术创新的巨大机遇,以及中国已成为造船大国并向造船强国转型的时机下,该公司如何布局中国的CAE市场?其仿真技术和方案能给中国船舶工业转型过程技术创新带来什么益处?带着这些问题,在一个初冬的早晨,本刊记者对这家的全球运营官ChristopherSt.John博士进行了专访。     

Estimating Recreation and Existence Values of Sea Otter Expansion in California Using Benefit Transfer

This article demonstrates how benefit transfer can quantify tourism and existence values. Existing literature values of sea otters and a meta analysis yield benefit estimates of several million dollars for the increased number of sea otters expected by USFWS in the next decade if the “no otter zone” is eliminated and otters allowed to expand along the Santa Barbara coast. These benefit estimates of sea otter expansion exceed the costs to commercial fishing. Thus the benefit transfer approach can contribute to a more complete economic analysis of endangered species recovery or critical habitat efforts than the current USFWS approach.     

The problem of misdeclared container weight: perspectives from New Zealand and implications for its law

This paper addresses the problem of misdeclaring container weights, which causes accidents on land and sea, with serious consequences. It reviews the current international law, and the verification of container weight mandated in the Safety of Life at Sea (SOLAS) convention, and relates them to New Zealand law and practice as an example. It concludes that the SOLAS plan, simply written into local law, is unlikely to be enough by itself to fix the problem. It considers the points in the supply chain where responsibility could be placed for weighing and proposes a “chain of responsibility” approach with initial weighing by the shipper and check weighing later, especially at ports, with misdeclared containers being reportable as incidents. Such a system should deal comprehensively with the problem.     

Reducing pedestrian exposure to environmental pollutants: A combined noise exposure and air quality analysis approach

This study offers a combined analysis of pedestrian exposure to noise and air pollution within a specific urban setting in Dublin, Ireland. The impact of a recent boardwalk development on reducing pedestrian exposure to air and noise pollution is examined while modelling experiments are undertaken to explore the possibility of achieving further reductions in pollutant exposure through better urban design and planning. The results show that the boardwalk has reduced pedestrian exposure to air and noise pollution and that further reductions may be achieved by more strict segregation of pedestrian and road traffic in urban areas.     

Estimating the Economic Benefit of SCUBA Diving in the Similan Islands,Thailand

This article reports the results of the travel cost model using the standard and the truncated count data models to estimate the economic value of the Similan Islands, Thailand, from SCUBA diving. The estimated consumer surplus per visit to the Similan Islands using the truncated negative binomial model was US$3,233 and the economic value of the Similan Islands from SCUBA diving was estimated to be up to US$54.96 m. This study shows that, even without non-use values, coral reefs of the Similan Islands, if properly managed and maintained, will continue to have significant value to both Thai and overseas SCUBA divers, as one of the natural treasures of the world.