形状记忆合金在土木工程中的研究与应用进展

形状记忆合金作为一种集传感和驱动于一身的新型功能材料,引起了土木工程界的广泛关注,对它的研究也日益深入,但应用尚处于起步阶段。回顾了形状记忆合金的发展过程,简单介绍了形状记忆合金的基本特性和本构模型;根据形状记忆合金在结构控制中所起的作用,分类概述了它作为被动控制器和主动控制器的研究进展以及在实际工程中的应用,重点介绍了SMA智能混凝土的研究情况;指出了当前形状记忆合金在土木工程领域研究中存在的问题,以及未来的发展方向。     

施工承包企业安全成本及其核算的研究

依据施工承包企业安全管理的目标、特点和程序,提出安全成本的概念和构成以及保证性安全成本对损失性安全成本的直接影响.同时,借助施工安全成本与安全度的关系、提高安全技术工作的经济合理性、加速构建施工承包企业安全成本核算制度,优化施工承包企业的安全管理工作,并为提高企业经济效益及社会经济运行的安全度奠定基础.     

Responding to security threats: livelihoods under protracted conflict in Sri Lanka

Populations affected by violent conflicts often withstand threats to their security as well as threats to their livelihoods. Their response to the former threats nontrivially affects their response to the latter threats, and vice versa. This paper examines the interplay between protection and livelihood strategies using a sample of households selected from the Anuradhapura district of Sri Lanka. The fieldwork for this study was completed in 2008, producing evidence that the protection and livelihood strategies employed by households affected by the protracted conflict in Sri Lanka are interlaced. In addition, the research discovered that Muslim and Sinhalese households largely responded to the protracted conflict in ways that are unique to their ethnic group. Certain vulnerabilities that impinge on protection and certain opportunities that support livelihoods are shown to be ethnicised. Hence, the final livelihood outcome, which is defined narrowly here as the household's income, also appears to be ethnicised.     

L'Aquila's reconstruction challenges: has Italy learned from its previous earthquake disasters?

Italy is an earthquake‐prone country and its disaster emergency response experiences over the past few decades have varied greatly, with some being much more successful than others. Overall, however, its reconstruction efforts have been criticised for being ad hoc, delayed, ineffective, and untargeted. In addition, while the emergency relief response to the L'Aquila earthquake of 6 April 2009—the primary case study in this evaluation—seems to have been successful, the reconstruction initiative got off to a very problematic start. To explore the root causes of this phenomenon, the paper argues that, owing to the way in which Italian Prime Minister Silvio Berlusconi has politicised the process, the L'Aquila reconstruction endeavour is likely to suffer problems with local ownership, national/regional/municipal coordination, and corruption. It concludes with a set of recommendations aimed at addressing the pitfalls that may confront the L'Aquila reconstruction process over the next few years.     

Persistence of the De-Icing Additive Benzotriazole at an Abandoned Airport

The environmental fate of many of the additives in the deicing agents used at airports is poorly understood. One and two years after deicing activities ceased, soil and groundwater samples were taken at an abandoned airport. Benzotriazole (BT), a corrosion and flame inhibitor, was found in low concentrations in soils along runways (mean 0.33 mg/kg), at a snow disposal site (0.66 mg/kg), as well as in sediments of a drainage ditch (13 mg/kg). Locally, high BT concentrations were found in the groundwater below the deicing pad, the regeneration plant and the snow disposal site (1.2 to 1100 g/l). Methyl substituted triazoles or tolytriazoles (MeBT) were found in concentrations less than 10% of the BT concentration. Propylene glycol was not detected in soil samples and in only one of the groundwater samples. Microtox tests of the water samples revealed no acute toxic response, however a reduction in nitrification rate was observed (14–43%). The nitrification response could not be related directly to the BT concentration in the samples, although samples with a high BT concentration showed the largest reduction in nitrification rate. BT showed very little sorption in various soil matrices, only peat and compost with a high organic carbon content showed significant sorption. Sorption could be best described using a Freundlich isotherm. These results indicate a high mobility and possibly long persistence of BT in soil and groundwater, which may be attributed to the absence of microbial degradation of BT.     

民航安全管理中岗位交叉培训方案的分析与研究

基于当前民航岗位安全培训仅局限于员工自身岗位安全的内容,而忽略了对于相关岗位安全之间衔接内容进行系统培训的现状,提出了民航岗位安全交叉培训;根据不同民航岗位间的具体关系,确定出需要进行交叉培训的岗位,利用FAHP模糊层次分析法选择出具体岗位(飞行员、管制员、机务员和签派员)之间的交叉培训方案;最后,根据选择结果,分别从交叉培训的性质、意义、前提等角度分析了民航安全管理中交叉培训的实施前景及需要注意的问题。     

构建民用航空安全体系探讨

探讨民用航空安全的研究体系,构建以基础层、过程层以及阶段层为主的空间结构研究体系。通过对空间结构体系的研究,针对我国民用航空安全管理现状及未来,提出了航空事故预防理论、事故救援理论和安全保障理论体系及技术体系,使民用航空安全的研究具备系统性、理论性、标准性及可持续性。     

我国民用机场建设运营的突出环境保护问题及解决对策

本文从我国民用机场的工程特点和环境影响分析入手,探究解决民用机场环境影响的对策措施,进而识别出民用机场建设运营的突出环境保护问题,重点探讨机场建设运营突出环境保护问题的解决对策措施,并提出我国民用机场建设运营在环境保护方面还存在哪些亟待解决的问题。     

机场围界入侵报警系统的设计

结合机场的地域特征,介绍一种检测人入侵行为的设计方案.以激光光电感应作为传感器件,通过对89052单片机进行C语言编程,检测和判断人入侵事件.通过大量实验获取样本时间点,利用聚类分析的算法有效排除掉噪声点,得到可靠样本空间,计算出可信赖样本阈值范围,经实验验证入侵判断误报率符合要求.     

基于运行安全的停机位分配问题研究

随着民航运输业的发展,航班密度不断增加,相邻停机位间推出冲突概率不断增加。为合理分配大型繁忙机场停机位,兼顾安全与效率,建立基于运行安全的停机位分配问题优化模型。在模型中加入约束条件以避免潜在的推出冲突,以及考虑将重要航班优先分配到指定的旅客行走距离较短的停机位,来提高旅客的整体满意度。通过分析机位分配特点,选择性能比较优越的遗传算法进行求解。最后用实际算例进行验证,得到停机位分配甘特图以及算法收敛曲线。从结果中可以看到,停机位分配比较合理,算法收敛性能良好。就整体而言,达到了预期的要求。