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赵志忠 《廊坊师范学院学报(自然科学版)》2013,(6):76-78
结合工程实例,采用消防安全评估的方法,从人员安全疏散性能化设计的应用研究的角度进行探讨,重点对疏散通道及安全出口设计、可用疏散时间TASET、必需疏散时间TRSET进行了分析。根据上述标准,认为乌兰察布市机场航站楼消防安全设计方案可行。 相似文献
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为了综合考虑人群个性和室内环境对疏散的综合影响,采用势能场元胞自动机(FFCA)模型模拟混合有不同性格行人的疏散.该模型构建了人群疏散环境的时空网络图,并通过计算最小运动消耗(LTC)路径建立静态势能场.疏散人群根据性格特征被分为3类,每类人群都可能使用不同的策略来平衡疏散中的运动和时间消耗.在每个时间步,每位行人都能根据随时变化的FFAC模型选择下一个移动目标.行人会根据自己的决策机制不断规划新路线或选择等待,直到到达出口.疏散模拟选择在不同的复杂疏散场景中进行,如多出口房间、教室和地铁,且疏散人群由不同性格的稠密人群混合而成.该研究为揭示行人心理、逃生环境与疏散行为之间的内在联系提供了一种新的方法. 相似文献
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我们研究了关联白噪声驱动单稳系统的平均首通时间(MFPT)与概率分布.通过比较解析与数值计算的结果发现它们的变化趋势是一致的.因此我们得到以下结论:(1)在不同的关联强度下,概率分布的稳态的位置不同,在正关联的情况下,稳态左移;(2)当弱关联时平均首通时间随着乘性/加性噪声强度的增大而减小,在强关联下,出现了一个峰值;(3)平均首通时间随着乘性与加性噪声的关联强度增大而增大. 相似文献
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依恋风格是个体与依恋对象在长期交往中所形成的系统性的情感和行为模式.近年来随着依恋的信息加工差异在很多研究中被强调,注意对依恋系统的影响显得更为重要,因此越来越多的研究开始关注不同依恋风格个体的注意偏向.本文主要从四个方面对依恋风格和注意偏向的研究进展进行了论述:(1)不同依恋风格个体对情绪信息的注意偏向特点;(2)注意偏向产生的机制;(3)相关的神经电生理学的研究;(4)目前研究的不足和对未来研究的展望. 相似文献
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《陕西教育学院学报》2017,(10):90-95
使用眼动技术,通过记录和分析88名4-6岁儿童对不同强度表情识别的成绩表现及眼动数据,探讨儿童识别不同强度表情的即时加工过程、发展状况及眼动模式,并在划分兴趣区的基础上,对不同强度表情识别过程中不同部位的优势效应进行分析。结果发现:(1)4-6岁儿童对不同强度表情的识别成绩随着表情强度增加而提高;(2)4-6岁儿童对不同强度表情的注视时间和注视次数随表情强度的增加而减少;(3)随着表情强度的增加,面部不同部位的作用会有所改变,如愉快表情的嘴部越来越重要,愤怒表情的眉眼部越来越重要。 相似文献
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为了计算教学楼在人流高峰发生火灾时,人员是否能在规程规定的时间内完成疏散,本文应用人员疏散优化网络模型,确定区域节点、水平通道节点、90度弯道节点、三岔路口节点、十字路口节点、逃生出口节点以及楼梯节点的疏散时间计算方法,建立教学楼式建筑火灾人员安全疏散预测模型,用于教学楼性能化的防火设计和事故预防。 相似文献
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测定了维生素D2在不同烷基化-β-环糊溶液中的溶解度,计算了包结稳定常数、包结率和增溶倍数,比较了不同烷基化-β-环糊对维生素D2的增溶作用.结果表明,包结常数和包结率随着取代度的增加而增加,并随着烷基链长的增加而增加;不同平均取代度的β-环糊精对维生素D2均有增溶作用,增溶倍数不但与取代度的大小和烷基的链长短有关,还与主体的浓度有关. 相似文献
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Niko Gärtner 《Journal of educational administration and history》2010,42(1):17-32
In September 1939, two days before declaring war on Germany, the British government evacuated over half a million children from London to supposedly safer areas in the country. Schoolchildren went there with their teachers and infants with their mothers. Immediately after the event (and ever since) the impact of the evacuation on the children – the hardships of some and the adventures of others – has been extensively researched, as has been the operation’s broader social impact. Meanwhile, the policy ontology of the evacuation’s organisation remains surprisingly under‐researched. This paper explores how the planning for the evacuation developed in a brief period before the outbreak of the Second World War, in order to assess responsibilities for its shape and ultimate execution. At the core of this article is the evaluation of four sets of documents from the archives of the London County Council about the evacuation’s planning stages in the 1930s. Contrary to earlier claims that the administration of the children’s evacuation was not only a success, but also an excellent illustration of co‐ordinated planning and execution, it will be the conclusion here, that not co‐operation and co‐ordination at government and civil service level made London’s evacuation a logistical success, but the relentless drive by the London County Council, who pushed for the evacuation in the face of opposition from central government. 相似文献
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This study examined rater effects on essay scoring in an operational monitoring system from England's 2008 national curriculum English writing test for 14‐year‐olds. We fitted two multilevel models and analyzed: (1) drift in rater severity effects over time; (2) rater central tendency effects; and (3) differences in rater severity and central tendency effects by raters’ previous rating experience. We found no significant evidence of rater drift and, while raters with less experience appeared more severe than raters with more experience, this result also was not significant. However, we did find that there was a central tendency to raters’ scoring. We also found that rater severity was significantly unstable over time. We discuss the theoretical and practical questions that our findings raise. 相似文献
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Chia Weng Boon Chee Wei Neo David Chew Chiat Ng Victor Chee Wee Ong 《浙江大学学报(A卷英文版)》2018,19(4):255-265
The design of rock support for a typical horseshoe shaped tunnel with considerations of it being excavated into a twin arch tunnel was studied using the distinct element method (DEM). Two different competent rock covers, i.e. 4 m and 7.5 m above the tunnel crown, were analysed. The results are relevant to the granitic geological unit in Singapore which has a weathering profile with rockhead found at some locations to be only 20–35 m below ground level and undulating, leaving limited rock cover for some sections along tunnels of similar depth. The verification of the adequacy of competent rock cover is important to ensure that the choice of ground support is suitable, particularly when the tunnel is excavated using the drill-and-blast method. In the opening geometry analysed in this study, a side drift is excavated adjacent to the first tunnel to create a twin arch opening. This creates a pillar between the openings during the intermediate construction stage. The influence of excavating the side drift on the support of the first opening was studied. We found that the bolt forces in the pillar approximately doubled during the excavation of the side drift, which may have been due to the rock joint inclinations and adopted strength parameters. This paper shows how DEM analyses may be used to complement conventional empirical rock mass classifications to design rock supports. Limitations of the pressure relaxation approach to model 3D effects in 2D are acknowledged. 相似文献
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基于性能化防火设计的研究思路,以A教学楼为例,讨论了教学楼现有疏散设施是否符合火灾场景下人员疏散要求。运用火灾模拟软件PyroSim建立火灾模型,得出影响疏散的温度、能见度、烟气的运动规律,选取最不利因素,确定可用安全疏散时间（ASET）。通过人员疏散软件Pathfinder模拟人员疏散路径,得出所需安全疏散时间（RSET）。研究结果表明,PyroSim与Pathfinder能有效的模拟火灾下人员疏散规律,A教学楼不能满足疏散要求,并提出改进方案以确保疏散安全。 相似文献
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The article gives a brief review on Hinkel’s study "The Use of Modal Verbs as a Reflection of Cultural Values",aiming at improving language teacher’s awareness that culture can influence language learners’ use of modals.At the same time,by pointing out the weakness of Hinkel’s study,the author suggests that the mere acquisition of linguistic competence is insufficient and teachers should integrate current research findings into their transmission of knowledge to learners. 相似文献
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Infants’ pointing gestures are a critical predictor of early vocabulary size. However, it remains unknown precisely how pointing relates to word learning. The current study addressed this question in a sample of 108 infants, testing one mechanism by which infants’ pointing may influence their learning. In Study 1, 18‐month‐olds, but not 12‐month‐olds, more readily mapped labels to objects if they had first pointed toward those objects than if they had referenced those objects via other communicative behaviors, such as reaching or gaze alternations. In Study 2, when an experimenter labeled a not pointed‐to‐object, 18‐month‐olds’ pointing was no longer related to enhanced fast mapping. These findings suggest that infants’ pointing gestures reflect a readiness and, potentially, a desire to learn. 相似文献
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鲁静 《湖北第二师范学院学报》2012,(2):53-55
本文以校园火灾环境为平台,提出一种安全疏散模型。该模型基于图的广度优先遍历和弗洛伊德算法计算每个建筑的危险程度,利用迪杰斯特拉算法搜索用户当前位置到各个疏散出口的最短路径,综合每个建筑的危险度和最短路径的长度计算了疏散代价函数,最终获得最安全、最高效的最优疏散路径。本文提出的模型不仅适用于校园环境,也对各类景区、城市交通等更加复杂环境下的安全疏散有一定的借鉴意义。 相似文献
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文章通过对日本、西班牙等发达国家巨灾保险制度的分析,指出了我国巨灾风险保险体系建设的不足与差距。对我国巨灾保险市场现状的分析显示,我国巨灾保险市场存在着巨大的保险需求和有限的制度供给之间的矛盾,解决巨灾保险市场供求失衡的矛盾需要在政府的主导下、在法律体系完善的前提下、构建政府与商业性保险公司共同运作的巨灾保险体系,从而实现制度供给的增加。同时,完善金融制度改革,为巨灾保险基金、巨灾风险债券的设立和发行创造良好的外部环境。 相似文献
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蔬菜中农残去除方法研究 总被引：3，自引：0，他引：3
以萝卜和菠菜为样品,采用正交试验,研究了不同方法组合对蔬菜中农残的去除效果.结果表明,去除根茎类蔬菜农残的方法组合为2%洗涤剂浸泡10min后,用自来水漂洗3次,每次1min后,再用沸水烫漂1min;去除叶菜类蔬菜农残的方法优化组合为2%洗涤剂浸泡15min后,用自来水漂洗2次,每次1min后,再用沸水烫漂1min. 相似文献
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Wendy Sutherland-Smith Kevin Dullaghan 《Assessment & Evaluation in Higher Education》2019,44(8):1148-1162
AbstractContract cheating sites advertise that they provide high quality, undetectable, bespoke work delivered in a timely manner to students purchasing their assignments. This paper tests contract cheating sites’ promises about the products they sell. We built on previous reported research examining contract cheating sites’ persuasive features which were mapped into three major dimensions. In this study, we explore how those dimensions are realised in practice. By purchasing 54 assignments from 18 different contract cheating sites across a range of disciplines, we found contract cheating sites’ promises flawed. Many sites do not deliver assignments on time, or at all; they provide variable quality assignments (including fail grade work), and do not necessarily respond rapidly to user queries. When markers graded work, 52% of cheated tasks failed to meet the university pass standard. Furthermore, many contract cheating sites retain the right to share personal details with third parties under their privacy clauses and require levels of personal identification that leave users vulnerable. Students need to be aware that contract cheating sites’ slick advertising is not necessarily borne out in reality. Universities can draw on this study’s findings for student awareness and deterrence campaigns pointing out the risks of using contract cheating sites. 相似文献