自由抛落式救生艇推进系统落水冲击响应计算分析

运用非线性多体动力学方法,建立某抛落式救生艇在主机怠速运转时推进系统的多体动力学模型,计算分析该救生艇落水时产生的冲击载荷对其推进系统主要轴承及艉轴的动态响应。结果表明：主轴承受力明显增大,轴心偏移增加6倍;艉轴承水平方向最大受力增大263%,垂直方向最大受力增大292%;艉轴水平方向弯曲振动偏移量增加190%,螺旋桨径向位移增大147%。曲轴和艉轴最大受力均在许用范围内,且有较大安全裕度,原来的设计方案不会对入水冲击带来不安全。这项研究为自由抛落式救生艇的可靠性设计提供了重要参考。     

Small-Scale Sicilian Fisheries: Opinions of Artisanal Fishers and Sociocultural Effects in Two MPA Case Studies

Marine resource management and related stakeholder conflicts have been clearly defined in recent decades as pressing issues worldwide. This article provides a comparative study of the management regimes of the Gulf of Castellammare Fishery Reserve and the Egadi Islands Marine Reserve in Sicily, Italy. What managers in these two reserves have neglected to include in management is a social science evaluation scheme to ensure the development of more effective overall management. This is a significant problem in both Italy and the rest of the Mediterranean, where few sociocultural and economic studies have been conducted. Using data collected with standard anthropological field methods, analysis was conducted on how artisanal fishers are impacted by reserves, the extent of their knowledge regarding regulations, their opinions on management, and demographics. The results indicate that while fishers in the two case studies are all aware of the marine reserves where they fish, most fishers are not well informed of the associated regulations. Fishers feel alienated from the management process, and would feel more comfortable with reserve managers and regulations if they were involved in management. The article concludes by showing how such data could help to develop more useful and practical management practices in both these and other MPAs with similar problems.     

规则波对弹性支承水平板冲击压力的概率分析

通过模型试验研究了规则波对弹性支承水平板冲击压力峰值的概率分布。文中通过对不同组次的试验数据进行统计分析,首先给出了弹性支承与刚性支撑之间水平板波浪冲击压力历时曲线的各自特征;其次研究了弹性支承水平板波浪冲击压力峰值的超值概率分布及拟合曲线和参数;最后讨论了弹性支承刚度与威布尔分布三参数之间的关系。     

Applications of Random-Utility-based Multi-region Input–Output Models of Transport and the Spatial Economy

Abstract

An introduction to random-utility-based multiregional input–output models used for the purpose of spatial economic and transport interaction modelling is provided. The main methodological developments and important results of a dozen applications from the years 1996–2013 are described. This is followed by an outlook of potential future directions. Further research is mainly needed in five areas: (a) overall validation of the method, perhaps through back-casting applications on infrastructure plans with observed trade impacts; (b) extensions of trade coefficient models to add realism and improve accuracy; (c) the use of multi-scale modelling to capture interdependencies between geographical scales and to improve the representation of exports and imports; (d) improvements in the representation of price effects, as well as innovation and technological progress, by way of variable technical coefficients; and (e) a deeper investigation of the algorithm used to include elastic selling prices.     

The risk of whiplash-induced medical impairment in rear-end impacts for males and females in driver seat compared to front passenger seat

The objective of this study was to study whiplash injury outcome in front-seat occupants in rear-end impacts using double paired comparison technique. The combination of gender, seated position, and outcome was analyzed. Folksam, a Swedish insurance company, has a database of whiplash injuries. A questionnaire was used to collect study data. The response rate was 81%. The inclusion criteria included medical impairment one year after the impact, as judged by medical specialists. The study included rear-end impacts between 1990 and 1999 that resulted in at least one permanent neck injury impairment; in total, 430 impacts with 860 occupants and 444 impairments. Of those suffering impairment, 302 were female and 142 male; 235 were seated in the driver's seat and 209 in the front passenger seat. Relative risk estimates for impairing whiplash injury, by gender and seated position:

1.

Driver male (DM)/passenger female (PF) relative risk = 0.5 n = 218     

冲击碾压技术在霍林郭勒民用机场工程中的应用

结合内蒙古自治区霍林郭勒民用机场飞行区填筑的填料特点、沉降控制及工期要求,通过分析冲击碾压原理及与普通碾压的区别,确定场区土石方填筑采用冲击碾压技术进行施工.综合试验段的填筑体检测数据分析结果,提出了土石方工程大面积开展时的施工参数.     

冲击碾压技术在粉土路基施工中的应用

针对粉土路基冲击碾压施工技术,阐述了冲击碾压施工处理技术原理及作业流程,并重点论述了冲击碾压技术处理粉土路基的施工质量控制要点,可以为相关工程项目的实施提供参考。     

移动行李对后排座椅冲击的仿真分析与结构优化

通过对移动行李对后排座椅冲击试验的一款不合格座椅进行仿真分析,结合试验结果验证分析模型的有效性。根据试验及仿真结果,分析座椅结构的不合理性,并进行优化设计,使其在重量减轻的同时满足GB 15083-2006的试验要求。     

简支梁桥冲击系数统计分析研究

列举部分国家规范对冲击系数的计算方法,并对大量简支梁桥实测冲击系数样本进行统计分析,得出结论：JTGD60—2004《公路桥涵设计通用规范》中冲击系数取值的安全储备略显不足。对样本数据进行回归分析,得到桥梁实测基频一冲击系数的回归方程,并基于此来研究冲击系数计算的改进方法。     

住宅项目交通影响分析方法研究

从住宅项目交通需求特点出发，提出住宅开发项目交通影响评价原则，指出了住宅开发项目交通影响分析流程。在进行交通影响分析中，交通需求预测是关键技术，采用了重力模型、层次吸引和走行路线3种预测方法，结合北京康泉新城住宅小区交通影响分析进行论述，并对项目周边公交线路服务水平，停车设施利用状况进行了分析评价。