The role of professional associations in shipping

This article is in three parts. The first covers the historical development of qualifying associations. The second covers the particular role of maritime institutions that include The Royal Institution of Naval Architects, The Institute of Marine Engineering Science and Technology and The Nautical Institute. The third and final section considers the future for maritime professional associations in the context of international shipping.     

龙屯路立交钢管混凝土简支系杆拱桥主桥设计研究

柳州龙屯路立交桥主桥结构形式为跨径92.5 m下承式简支系杆钢管混凝土拱桥,通过分析结构体系的温度敏感性,本桥接近同类结构形式的极限跨度。主要介绍该桥的结构设计和结构静力计算情况,并对结构的合理拱轴系数进行分析研究。     

"讨债"期限的时效

“讨债难”的现象在水运企业、个体船户间司空见惯,人们对此已见怪不怪。经营业务中,经常遇到这样一种情况:甲方欠乙方的运费,由于种种原因到了合同约定的付款期限没有付清。后来虽经乙方多次上门催要,甲方仍未偿还,最后乙方不得不将甲方诉诸法庭。但结果却是:由于乙方因没有证     

A high order linear model for the prediction of internal lee waves at the main sill of the Strait of Gibraltar

A linear theory for the physical fields in the water column under the action of large amplitude internal lee waves at the main sill of the Strait of Gibraltar is developed. The procedure is a combination of the perturbation and normal modes methods in order to study steady resonant conditions. The lowest order linear approach of the methodology resumes the Taylor–Goldstein equation, which can reconstruct the main features of the observed fields but the high order approach gives the finest structure and sometimes the largest contributions. The role of the non-linear terms is investigated up to the second order taking into account the non-linear interactions between modes, leading to an effective reconstruction of the whole water column for the velocity field.     

A traffic flow simulator for short‐term travel time forecasting

This paper presents an off‐line forecasting system for short‐term travel time forecasting. These forecasts are based on the historical traffic count data provided by detectors installed on Annual Traffic Census (ATC) stations in Hong Kong. A traffic flow simulator (TFS) is developed for short‐term travel time forecasting (in terms of offline forecasting), in which the variation of perceived travel time error and the fluctuations of origin‐destination (O‐D) demand are considered explicitly. On the basis of prior O‐D demand and partial updated detector data, the TFS can estimate the link travel times and flows for the whole network together with their variances and covariances. The short‐term travel time forecasting by O‐D pair can also be assessed and the O‐D matrix can be updated simultaneously. The application of the proposed off‐line forecasting system is illustrated by a numerical example in Hong Kong.     

内燃机车牵引噪声源的噪声贡献量的统计能量分析(SEA)研究

以东风４型内燃机车为例，用简化了的内燃机车车体结构，建立了定置状态下３种输入情况的内燃机车的统计能量分析（ＳＥＡ）模型，得出了与机车在负荷试验台上进行试验时相符的模型，给出了机车各主要牵引噪声源对环境的噪声贡献量的计算方法，并实验验证了理论分析的结论．     

浅析现代科技对测绘的影响

测绘技术是随着科技的发展而不断进步的,促进了测绘技术的一次次革命,到今天功能齐全的网络测绘技术,无不显示了科技对测绘技术的影响力。本文主要讨论了高科技测绘技术的特点,并在此基础上介绍了几个当今比较流行的信息测绘技术,然后讨论了信息技术带给测绘工业体制上改革,以及最终信息化测绘的发展方向。     

儿童慢型克山病的自然病程

为了探讨儿童慢型克山病的自然病程和预后危险因素，本文分析了长期随访的儿童慢型克山病６３例，结果表明：①儿童慢型克山病预后差，其１年存活率５０．５％、５年仅１５．８％；②自然慢性发病、有奔马律、心功能Ⅲ级以上，心电图心室增大，Ｘ线心胸比率重度扩大者，５年存活率低（Ｐ＜０．０５或０．０１）。     

摩托车电喷发动机转速测量系统的设计

转速是摩托车电喷系统点火和喷油所依据的重要参数之一,转速测量是电喷系统的关键技术。比较器调理电路和555芯片调理电路经过实际调试均能正常工作,但从可靠性和抗干扰角度考虑,555芯片组成的施密特触发器要比比较器电路可靠性高,抗干扰能力强。文中介绍的单片机测量计算转速的2种方案,实践证明准确可行。     

SLENIUM FROM BEEF IS HIGHLY BIOAVAILABLE AS ASSESSED BY LIVER GLUTATHIONE PEROXIDASE （EC1．11．1．9） ACTIVITY AND TISSUE SELENI

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