多组分细水雾对乙醇汽油的灭火效能研究

分析了细水雾灭火时液滴的吸热蒸发过程和汽油与乙醇汽油的燃烧特性，进行了汽油、乙醇在封闭空间内从燃烧到自行熄灭时的含氧量变化测量。进行了多组分细水雾与细水雾的灭火性能比较，和用多组分细水雾对汽油火、乙醇汽油火的灭火性能试验。研究表明，多组分细水雾比普通细水雾具有更好的灭火效果，乙醇汽油火的灭火难度要比汽油火的大，多组分细水雾用于乙醇汽油场合灭火时，其灭火工作压力要大于用于汽油的场合。     

森林火灾过程中的火旋风特征

火旋风是森林火灾过程中的特殊火行为现象。它给火灾的扑救指挥工作带来难度，给扑火人员的人身安全带来严重的危害。本文简要介绍了火旋风的一些特征和模化研究，作为对火风的认识和理解，供林火扑救和安全防范以及深入研究探讨参考     

高层建筑典型外墙保温材料火蔓延特性数值模拟研究

有机保温材料被广泛应用于高层建筑外墙保温体系的同时,也可能增加高层建筑的火灾风险。本文通过计算机模拟,着重研究了保温材料之一的聚苯乙烯泡沫塑料(EPS)的火蔓延速率、失重速率及温度场分布等特性。研究结果发现:发生火灾后,外墙保温材料可以在很短的时间内自下而上蔓延至整个材料表面,并有表皮着火的现象。在火焰到达材料顶部之前,向上火蔓延占主导地位,材料中部区域明显燃烧脱落,火焰在材料两端上部继续燃烧,有向下加速蔓延的趋势;之后,火焰沿着材料中部内侧向下剧烈燃烧,材料呈V字型燃烧直至熄灭。在高层建筑外墙外保温材料火蔓延中,不同着火点情况下的燃烧速率随时间变化的趋势相似,且会形成两个波峰。     

不同受火方式下混凝土框架结构的变形研究

针对单层框架和三层框架,通过高温数值分析,初步考察了不同受火方式下结构的变形特征。研究发现:①火灾蔓延对结构高温变形影响较大,此时节点的水平位移总体上小于结构全层/全部受火时的相应结果;②受火区间仅对相邻跨或相邻层有一定影响,而对隔跨或隔层影响相对较小;③非对称局部受火情况下,单层框架边节点的水平位移可能比全层受火时更大。     

环境压力对细水雾喷雾特性影响的实验研究

雾滴的粒径分布、喷雾强度、雾滴动量及雾场的分布形式等喷雾特性,直接影响细水雾的灭火性能。本文通过研究压力漩流雾化实心锥及空心锥喷嘴在不同环境压力下的喷雾特性,揭示了环境压力对细水雾喷嘴流量系数及其雾场分布的影响规律。实验结果表明:环境压力越小,雾滴越向雾场锥面集中,雾场边缘区域的喷雾强度越大,而中心区域喷雾强度随之减小;环境压力对细水雾喷嘴流量系数则无明显影响。     

莫让消防栓成了“空摆设”

不久前,某大型化工企业职工住户家里突然冒出浓烟。有人打开楼道内消防箱,试图引水扑火,却发现竟没有水管。几分钟后,消防队员上楼拧开楼道里的消防栓,竟没有水流出。无奈之下,消防队员只好从一楼架水管将火扑灭大火熄灭后,房内一片焦黑,家中物品全部被焚毁,人们眼睁睁地看着火把房间烧光。"要是消防设施完好,损失绝不会这样惨重。"邻居们惋惜地说。面对时有发生的火灾事故,我们谁也不能置身事外。必须看到,频频见诸电视、新闻报道中的火灾事故,其中的种种细节与隐患,不仅存在于火灾现场中,也存在于我们身边。令人忧虑的是,     

三跨连续板抗火性能的有限元分析

采用有限元方法对三跨连续钢筋混凝土板局部受火和整体受火下的结构响应进行了数值模拟。结果表明,结构受火位置和受火范围不同时,产生的塑性区位置和范围不同,出现破坏铰的位置不同,但是经过模拟发现塑性区域都是在中间支座附近,破坏铰都是在负筋截断形成,因此结构的负筋长度对结构的耐火性能影响很大;结构在整体受火情况下由于整个结构绕塑性区的抬升作用,造成塑性区附近中跨的抬升,加温结束后整个中跨呈隆起形式,但是中跨局部受火时其中点始终产生向下的挠度,因此在局部受火与整体受火时结构的整体变形不同;在局部受火的时候,由于结构的整体作用使受火跨和未受火跨之间有很大程度的内力调整,这种内力重分布可以很好地提高结构的抗火性能,结构在局部受火的时候耐火性能比整体受火时好出很多。     

森林火灾气象环境要素和重大林火研究

利用1970～1994年25年间的森林火灾资料,分析研究了湖北省神农架林区森林火灾的火源,火环境条件,林火发生、发展、蔓延和熄灭过程的天气气候特征及重大林火燃烧期的某些要素特征,对指导森林防火灭火具有现实意义.     

钢结构梁柱节点抗火性能研究进展与展望∗

钢结构不耐火,在一定程度上制约了钢结构的应用和发展。为了探明钢结构在火灾下的工作性能,对钢结构基本构件的抗火性能进行了大量研究,提出了相应的设计理论与方法。梁柱节点是钢结构中十分关键的部位,在火灾下的可靠连接是保证钢结构火灾安全的重要前提。为了全面了解钢结构梁柱节点在火灾下的受力性能和破坏机理,从试验研究、有限元模拟和组件分析法三个方面系统地梳理了国内外关于节点抗火性能的研究进展。比较了高温下不同类型节点的力学性能,探讨了多种关键参数对节点在火灾下工作性能的影响规律,介绍了不同类型节点的高温组件分析模型以及弯矩―转角曲线数学模型。分析表明:节点构造形式对钢框架火灾安全有较大影响;通过设置柱腹板加劲肋、提高螺栓强度等级以及增加连接件的厚度等可以有效地提高节点的抗火性能。最后剖析了钢结构梁柱节点抗火研究中存在的不足,对未来值得关注和重视的关键问题提出展望。     

局部火灾羽流中心线温度计算模型及试验研究

火羽流中心线温度是局部火灾作用下整个建筑中的最高温度,获得该处温度便可对结构的火灾安全性能进行初步评判。目前比较著名的羽流温度计算模型有Zukoski模型、Heskestad模型和McCaffrey模型,Zukoski模型和Heskestad模型因不适用于火焰区的温度计算而需要修正。为了验证各个模型的适用性,在室内外开展了功率为154.4、903.2kW的小型柴油油池火试验,并将试验结果与各计算模型的计算值进行对比。同时采用各模型分别对小功率、中功率和大功率火灾的羽流中心线温度进行计算对比,在对比分析的基础上给出了大空间建筑局部火灾羽流中心线温度计算公式。     

Cholera in Sudan: An account of an epidemic in a refugee camp in eastern Sudan, May-June 1985

In 1985 cholera has been a serious problem in the horn of Africa, particularly affecting the many famine victims and refugees in that region. In this paper the history of cholera in Africa is briefly summarized, as is the background to the current refugee situation in eastern Sudan. A cholera epidemic involving 1,175 cases in two adjacent refugee camps in eastern Sudan is described. In this epidemic there were thirteen inpatient deaths and thirty-eight known home deaths from cholera. The management of the epidemic is described in detail. Overall an average of 8 1. of intravenous fluid was used per case, a higher figure than was anticipated, probably because of the unexpected degree of vomiting and the shortage of trained nursing staff.
The relationship between cholera and malnutrition is explored and hypochlorhydria is suggested as the main reason for the increased susceptibility to cholera among malnourished populations. It was observed that severely malnourished adults and children appeared to nave less severe diarrhoea with their cholera, presumably because of reduced mucosal surface area and poor enterocyte function. Finally possible means of aborting cholera epidemics are discussed.     

A retrospective statistical review of deaths owing to migration through the southeasternmost land borders of the European Union,Greece 2000–14

The land borders of Evros, Greece, have been a common entry point for undocumented migrants on their way to Europe through Turkey. Adverse conditions, however, have resulted in many human casualties over the years. On the Greek side, 334 cadavers were retrieved between 2000 and 2014. This study provides a detailed forensic account of the humanitarian disaster in Evros to create an official scientific record of the situation. It showcases the gravity of the global issue of migration relating to health and mortality, and encourages communication and continual improvement of the approach and patterns of practices surrounding the subject. A retrospective statistical research review was conducted of border‐related fatalities between 2000 and 2014, assessing the age and gender of victims, the cause of death, the location of bodies, identification rates, and country of origin. Age ranged generally from 24 to 29 years, but infants and children were among the deceased.     

Complexity,continuity and change: livelihood resilience in the Darfur region of Sudan

Darfur farming and pastoralist livelihoods are both adaptations to the environmental variability that characterises the region. This article describes this adaptation and the longer‐term transformation of these specialised livelihoods from the perspective of local communities. Over several decades farmers and herders have experienced a continuous stream of climate, conflict and other shocks, which, combined with wider processes of change, have transformed livelihoods and undermined livelihood institutions. Their well‐rehearsed specialist strategies are now combined with new strategies to cope. These responses help people get by in the short term but risk antagonising not only their specialist strategies but also those of others. A combination of factors has undermined the former integration between farming and pastoralism and their livelihood institutions. Efforts to build resilience in similar contexts must take a long‐term view of livelihood adaptation as a specialisation, and consider the implications of new strategies for the continuity and integration of livelihood specialisations.     

Reflections on 40 years of Disasters, 1977–2017

This reflection, based on a keynote address to celebrate the fortieth anniversary of Disasters on 14 September 2017, begins by considering some of the prevailing assumptions that existed at the time of the journal's creation. Next is a summary of significant milestones during the past 40 years, covering major global trends, changing disaster impacts, and key developments in disaster risk management. Contrasting approaches in the first and fourth decade of the journal's history are then followed by examples of changes in terminology in the disaster field as an indication of shifting values. The paper goes on to explore the context of 2017, with observations of problem areas such as the loss of knowledge, failures to tackle the root causes of disasters, shortfalls in international assistance, and some negative attitudes. It closes by evaluating some current positive occurrences, including a reduction in casualties, sharing of experience, technological advances, and dramatic improvements in disaster warning.     

Fiji, land of tropical cyclones and hurricanes: A case study of agricultural rehabilitation

Tropical cyclones and hurricanes have a severe impact on the social and economic activities of affected communities. For small island nations in the Pacific region, the effects can be devastating because of their smallness. FQi and several other countries in the region are vulnerable to such disasters as they are situated in the zone where cyclones occur frequently.
During the last decade, the frequency of natural disasters and their adverse impact on die economic and social development of small nations like Fiji, has aroused awareness mat relief efforts must go beyond immediate "mopping up" operations to those which contribute to attaining longer term benefits through reconstruction and rehabilitation.
The paper outlines the 1985 agricultural rehabilitation program and discusses related issues and problems.     

Tsunami survivors' perspectives on vulnerability and vulnerability reduction: evidence from Koh Phi Phi Don and Khao Lak, Thailand

This paper presents the results of primary research with 40 survivors of the 2004 Indian Ocean tsunami in two communities: Khao Lak (n=20) and Koh Phi Phi Don (n=20), Thailand. It traces tsunami survivors' perceptions of vulnerability, determines whether residents felt that the tsunami affected different communities differently, identifies the populations and sub-community groups that survivors distinguished as being more vulnerable than others, highlights community-generated ideas about vulnerability reduction, and pinpoints a range of additional vulnerability reduction actions. Tsunami survivors most consistently identified the 'most vulnerable' community sub-populations as women, children, the elderly, foreigners, and the poor. In Khao Lak, however, respondents added 'Burmese migrants' to this list, whereas in Koh Phi Phi Don, they added 'Thai Muslims'. Results suggest that the two case study communities, both small, coastal, tourism-dominated communities no more than 100 kilometres apart, have differing vulnerable sub-groups and environmental vulnerabilities, requiring different post-disaster vulnerability reduction efforts.     

火灾场景中玻璃破裂行为研究综述

建筑物在火场中的结构响应问题中,门窗玻璃在火场中的热响应特性及破裂脱落是影响火灾发展的重要因素之一。通过事故案例分析了火灾场景中玻璃破裂脱落的危害性,指出了研究火灾场景中玻璃受热破裂脱落的意义,并对目前火灾场景中玻璃受热破裂过程和主要形态、玻璃的破裂机理和判据等的研究现状进行了详细的分析,总结了目前实验和计算机模拟的最新研究进展和不足,为今后进一步开展玻璃受热破裂脱落研究提出了若干建议。     

中国内陆自然环境的干旱化与未来趋势

根据中国内陆陕西、甘肃部分地区５０９ａ旱涝资料和主要测站气象、水文实测数据,应用Ｗｏｒｄ９７图形处理系统,证明在５２６ａ序列中目前处在１１ａ、５０ａ滑动的干旱期。近４６ａ气温上升了０．３℃,年降水减少了８０ｍｍ,径流量减少了０．７８％,出现了明显的干旱化,环境变化趋势不容乐观。     

美国的洪泛平原管理

美国开展洪泛平原管理已有约40年历史，洪水保险计划是美国泛平原管理的主要措施。了解并借鉴他们的思路与具体策略，将有助于我国洪泛平原管理政策的制定。     

A general assessment of the environmental impact of refugees in Somalia with attention to the refugee agricultural programme

This paper attempts to examine the broad features of Somalia's harsh physical environment into which several hundreds of thousands of refugees, with mainly a nomadic or semi-nomadic life style and culture, dramatically descended six years ago. The thirty-six rural camps in which at least half of them live are described as is the refugee agricultural programme which is training several thousand families so that they may be "self-supporting." The four regions where the camps are located are each briefly summarized in terms of their soils, their climates, their natural vegetation, and the type of agriculture which the refugee farmers practice. A more detailed analysis is then given on the following critical environmental concerns: Vegetation and erosion on refugee farms, the growing problem of refugee livestock, the destruction of trees, and irrigation practices and salinity on refugee farms. The paper concludes with an argument to preserve Somalia's environment from careless and destructive exploitation, which is leading towards desertification, and calls for an in-depth study of the situation.