大型商业综合体建筑的消防策略研究

改革开放以来,我国社会形式逐渐向现代型城市转变,新时期城市化进程呈现跨越式发展,包含公共服务、公共娱乐、公共交通等功能的大型商业综合体建筑明显增多,其整体建筑规模、体量还在不断增大。大型商业综合体经营业态和结构功能复杂,各类风险隐患互相威胁、交织叠加,火灾风险远超单一使用功能建筑。一旦发生火灾事故,烟气难以有效排出,不易清晰判断起火点,火势将在建筑内部快速蔓延,灭火救援行动难度较大,极易造成严重的经济损失和人员伤亡。文章简要分析了以大型商业综合体消防安全管理工作的重要作用,在梳理代表性风险隐患的基础上,提出了几点针对性消防安全管理措施。     

组合赋权法确定地质灾害危险性评价指标权重

针对现有地质灾害危险性评价中指标权重确定方法的不足,首先基于粗糙集理论提出了指标相对重要度的计算公式,并对主观赋权法中的AHP法进行了改进;然后与客观赋权法中的熵值法进行综合优化,求得评价指标的组合权重;最后,提出了一种综合分析方法来选取评价指标主、客观权重的偏好系数u值。该方法综合考虑了指标的主、客观成分,将专家判断和客观分析相结合,可以得到较为理想、合理的权重值。     

Real-time biomonitoring of water contamination by cyanide based on analysis of the continuous electric signal emitted by a tropical fish: Apteronotus albifrons

A new early warning system for monitoring the quality of water was developed using the information conveyed by the continuous electric organ discharges of the tropical fish Apteronotus albifrons (Gymnotiformes, family Apteronotidae). The principle is based on the time characterisation of the electric signal emitted by the fish and uses the fact that the frequency and the form of the signal vary as a function of the physico-chemical quality of the ambient water. Eight test fish were individually confined in a heat-proof test chamber in which a continuous water current, thermo-regulated at 27°C, was maintained. The electric signal sampled over 1 s periods were amplified. The computer processed the signals and their frequencies and determined the coordinates of the points where the temperatures were recorded. The results of the A. albifrons electrical activity were then visualised on a visual display unit. Subsequent mathematical processing helped to detect unusual electrical behaviour (crossing of lower and upper bounds). To illustrate the principle of this new early warning system, the electric response of the A. albifrons exposed to cyanide was tested and compared with the detection thresholds of other biological early warning systems. A. albifrons is able to detect a cyanide concentration of 34.6 μg l⁻¹ in less than half an hour. The recorded results suggest that this new biomonitor corresponds very well with the requirements of warning stations for surface waters subject to cyanide pollution.     

区域滑坡空间预测方法研究及结果分析

区域滑坡空间预测是通过分析滑坡在区域空间分布的丛集性及规律性,圈定出滑坡相对危险性区域。通过MAPGIS软件平台及其二次开发的滑坡灾害分析系统,采用半定量和定量两种方法对浙江省永嘉县区域滑坡进行了预测。半定量方法采用反映历史滑坡强度的袭扰系数和滑坡易发程度指数来评价,编制了危险性预测分区图;定量化方法采用信息量模型来评价,采用规则网格作为预测单元,运用该模型对永嘉县区域滑坡进行了空间定量预测,并依信息量法的结果编制了该区的危险性划决预测分区图,为政府部门进行土地规策、避免在滑坡易发区进行大规模土地开发和工程建设提供了科学依据。同时通过两种方法的预测结果,对比分析了滑坡的形成和各影响因素的关系,为滑坡的有效防治提供了参考。     

公路工程监理风险评价

本文从工程项目实施阶段着手,详细分析公路工程监理承担和必须承担的风险。通过列举工程项目潜在的风险因素,采用风险量量化排序方法评价各种类型风险的重要程度,提出相应的风险对策讨论及完善工程监理制的问题。     

防火规范中若干条文探讨

为了使现行防火设计规范更切合实际,分别就消防水箱及气压设备的设置、住宅设置自喷系统的火灾危险等级、防火卷帘的耐火极限等条文中出现的问题提出了个人看法,建议对规范中部分条文作适当调整。     

车用乙醇汽油火灾危险性评估及对策

以车用乙醇汽油为灭火对象，对其危险品参数及热工参数进行了测试，得出了其火灾危险性与汽油较为接近的结论，通过泡沫选型，供给强度、施加方式及灭火器等大量试验，建议采用抗溶性泡沫灭火剂灭火。采用干粉灭火器保护时，要适当增加灭火器的配置数量。     

超高层建筑场地地震动参数的确定

基于抗震设计的重要性,以厦门某超高层建筑场地为例,在场地地震危险性概率分析的基础上,对场地土层进行了一维地震反应分析计算,确定了该工程场地地震动参数,为抗震设计提供了依据.     

Patterns of exits from housing in a homelessness system of care: the case of Calgary,Alberta

Public officials around the world seek to target subsidized housing as purposely and efficiently as possible. With limited availability of subsidized housing, it is helpful to know which household types require specific types of housing support and for how long. With this in mind, we undertake survival analysis and hazard models on clients placed into housing funded by the Calgary Homeless Foundation (CHF) to characterize patterns of exit from Calgary’s homeless system of care. To do this, we use data from Calgary’s Homelessness Management Information System from 1 April 2012 until 31 March 2015. We find singles without dependents to require housing support for the longest period of time, while families require the support for the least amount of time. One important finding is that women require housing support for longer periods of time than men (even though we control for employment and income).     

基于Matlab的BP神经网络在泥石流危险性评价中的应用

由于泥石流孕育环境、成灾条件及其诱发因素等的随机性、不确定性和模糊性,决定了泥石流是一种非常复杂的非线性系统。人工神经网络因其具有较强的自组织性、自适应性和自学习能力等优势,更适合于解决非线性问题。本文基于Matlab程序建立了区域泥石流危险性评价的BP神经网络模型,并将该模型应用于凉山州德昌县22个乡镇的区域泥石流危险性评价中,取得了良好的应用效果,评价预测的准确率高达95%。该方法不仅解决了泥石流危险度评价因子和评价等级之间的复杂非线性关系,而且过程简单,结果不受人为因素的影响,是一种具有应用价值、有效的泥石流危险性评价方法。