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ABSTRACTThe preservation of artefacts in museum collections is profoundly affected by fluctuations in temperature and, especially, relative humidity (RH). Since the late nineteenth century, many studies have been carried out on the best way to control hygrothermal conditions. In old buildings located in maritime temperate climate zones (such as Portugal) with strong thermal inertia, and which have low ventilation rate (relative to the volume and number of visitors), daily and seasonal hygroscopic inertia may help to assure the maintenance of RH stabilization conditions. The use of expensive active systems may be minimized through the passive behaviour of internal finishing building materials. This work presents the results of an experimental laboratory study conducted in a flow chamber to demonstrate the enormous potential of hygroscopic materials in stabilizing interior relative humidity. Based in these results and in-situ monitoring in a museum housed in a building, located in Porto, with a typical construction of the 1950s (granite masonry and reinforced concrete slabs), a numerical analysis was done to quantify the influence of hygroscopic materials in stabilizing the interior relative humidity. 相似文献
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高等教育大众化背景下的大学生稳定工作 总被引:2,自引:0,他引:2
张佐 《湖州师范学院学报》2002,24(2):107-110
高等教育从精英阶段向大众化阶段的转变,既为高等教育的发展提供了广阔的前景,也产生了一些影响大学生稳定的新因素,如教育资源的相对短缺,学习费用上升,毕业就业困难,特困生增多。当前,要做好大学生稳定工作,必须有针对性地加强形势政策教育,必须建立大学生的舆情调查、分析、反馈体系,必须构建强有力的就业指导,服务体系和帮困体系。 相似文献
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丧失是人类生命历程中最为深重的情感,在不同的文化背景下,人们对丧失与哀伤有着不同的言说,每个个体对丧失的理解不同,就意味着对生命意义的理解不同,也意味着面对丧失与哀伤的方式不同。本文通过对几个有关丧失的个案,讨论了如何在中国文化容器下安放哀伤与哀悼,促进当事人的稳定化。 相似文献
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刘兴文 《西安铁路职业技术学院学报》2007,(2):32-33,12
本文以陇海线某铁路浇基桥梁的加固防护设施为工程背景,分析了该浅基桥梁被洪水冲毁的主要原因。并针对既有加固防护体项面与河床最低点之间存在高差的问题,提出了合理确定该高差最大的值的方法。 相似文献
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为进一步揭示滩涂淤泥固化土的强度特性及其影响因素,对以沿海滩涂淤泥为原料土、水泥-粉煤灰作为主固化剂配置固化而成的滩涂淤泥固化土的强度特性与固化机理进行了试验研究。通过无侧限抗压强度试验,详细探讨了水泥、粉煤灰、减水剂、石灰、石膏、三乙醇胺、硫酸钠、氯化钠等主固化剂和外掺剂对滩涂淤泥固化土强度特性的影响,分析了固化剂和外掺剂对提高固化土强度的机理。结果表明:龄期以及水泥、减水剂、石灰、石膏、粉煤灰、三乙醇胺、硫酸钠和氯化钠等的掺量均对固化土的强度有影响。水泥和粉煤灰掺量越多,固化土的强度越高,而外掺剂,如减水剂、石灰、石膏、三乙醇胺、硫酸钠和氯化钠的掺量存在临界值。在临界值内,固化土的强度随外掺剂的掺量的增加而增加,超过该值后,则随外掺剂掺量的增加而减小。龄期对固化土的强度有较大影响,7 d龄期下的固化土的强度要远小于28 d时的强度。 相似文献
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本文提出了一种基于混沌变量的模糊控制器设计方法,结合融合技术用以解决模糊控制器的规则爆炸问题。针对二次型最优控制中加权矩阵较难确定的问题,引入混沌大范围粗搜索和局部细搜索相结合,进而搜索出全局最优的权系数,用以提高控制的性能。通过二级倒立摆实物控制实验结果说明该方法是有效可行的。 相似文献
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Turo-Kimmo Lehtonen 《Journal of Cultural Economy》2014,7(3):308-333
What kind of object is private life insurance? To discuss this question, this article examines how life insurance is pictured, that is, explained and concretized with words and visual images, in the promotion of private life insurance in Finland between 1945 and 2000. In principle, life insurance can only be used for assessing and securing the economic value of life. The empirical material shows, however, that life insurance, as an object, can only exist if economic value and other values constantly overflow into each other, and calculation and affect are made to intertwine. In order to objectify their potential customers' lives as economic potential, as commodities, insurance companies have indeed had to objectify life – yet not only in terms of monetary value, but simultaneously and as importantly, also as something that is irreducible to monetary value. Hence the promotion of life insurance enacts a double stabilization of objects. On the one hand, advertisements and leaflets show how life insurance matters, what it is capable of, and thus stabilize the understanding of insurance itself as a tool. On the other hand, the promotional materials both stabilize and mobilize ‘life’ as an assemblage of heterogeneous practices and modes of valuation that is irreducible to economic potential. 相似文献
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Middle school students (n = 354) were tested for their understanding of the control of variables strategy (CVS) 2.5 years after participating in a study comparing three different interventions for teaching CVS. The key finding was that the pattern of effects observed in the 4th grade continued to be observed in the 6th grade. This was because (a) students who had mastered CVS in the 4th grade were likely to continue to perform at mastery levels in the 6th grade whereas (b) the learning of students who had not mastered CVS in 4th grade was independent of the teaching intervention they had received in the 4th-grade study. These findings demonstrate that a brief intervention of direct instruction in CVS can produce long-lasting learning of the principle of controlling variables. 相似文献
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刘薇 《乌鲁木齐职业大学学报》2013,(4):36-39
从维护新疆稳定发展大局和时代发展对新疆的要求出发,从包容到民族团结的共同意识的形成,建构起对国家和中华民族的认同意识,同时以稳定作为寻求各民族共识的切入口,形成新疆各民族学习和接纳其他文化达成共识的时代诉求。 相似文献