The Influence of Hygroscopic Materials on the Fluctuation of Relative Humidity in Museums Located in Historical Buildings     

C. Ferreira  V. P. de Freitas 《文物保护研究》2020,65(3):127-141

ABSTRACT

The 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   

多自由度刚性杆系静平衡计算     

沈健  董达善 《上海海事大学学报》2003,24(2):146-149

介绍了多自由度刚性杆系静平衡的分析计算。通过调整初始设计中杆件的长度来优化系统。这对于大型起重机前大梁拉杆系统以及一些相关系统的设计优化有一定的实际参考及应用价值  相似文献   

对第一次世界大战时意大利中立问题的认识     

孙银钢  董大学 《首都师范大学学报(社会科学版)》2005,(Z1)

第一次世界大战时,意大利发表中立宣言,中立选择有其深刻原因:战前意大利同其两个最为重要的劲敌法奥之间的关系发生根本性转变,意法关系由高度紧张走向缓和并趋于稳定,而意奥之间暂时冷却的深刻矛盾渐渐暴露出来,意奥关系至战前已相当紧张;焦利蒂时代的“平衡政策”是中立选择的依据。战时意大利政府决策的转变,新政府期望通过战争谋求强国身份和分享战争果实,将意大利带入其难以负担的世界大战。  相似文献   

湖南省田径队男子三级跳远成功的启示     

谢朝辉  熊卫  钟大鹏 《湖北体育科技》2003,22(1):93-94,96

通过湖北省田径队优秀男子三级跳远运动员熊卫在湖南省田径队男子三级跳远组训练过程的分析，认为教练员科学的、极具鲜明特点的训练方法，以及与运动员团结协作，努力拼搏，无私奉献的敬业精神，是湖南省男子三级跳远取得成功的关键。  相似文献   

江泽民舆论监督思想初探   总被引：1，自引：1，他引：0  

田大宪 《陕西师范大学学报(哲学社会科学版)》2002,31(1):66-73

江泽民舆论监督思想是马克思主义新闻观的继承和发展。江泽民“三个代表”重要思想是舆论监督的总纲。党和人民的根本利益是舆论监督的出发点和归宿 ;正确的舆论导向是舆论监督的前提 ;遵循新闻规律是舆论监督的依据 ;发挥监督系统的整体合力是舆论监督的有效途径  相似文献   

青少年足球运动员的速度力量训练     

杨大强 《体育成人教育学刊》2002,18(3):84-85

速度力量是速度与力量的综合表现 ,它的提高受速度素质与力量素质的牵制。力量和速度是青少年足球运动员快速能力的决定因素。速度力量的典型表现形式是爆发力、起动力、反应力。提出青少年足球运动员力量素质发展的敏感期与必要性 ,对速度力量的理论与实践作了概述。  相似文献   

视频元数据全文检索系统的研究与实现   总被引：3，自引：0，他引：3  

陈玮  陆达 《情报学报》2004,23(1):32-35

本文阐述了采用XML文档按照MPEG 7标准描述视频数据的趋势 ,研究了适合于半结构化视频描述的全文检索索引结构。该索引保存了文档中的结构信息 ,从而可以对视频数据进行全方位多层次的查询。提出了一些缩减索引空间的策略和算法。  相似文献   

WhatsApp as a Tool for Participation on Spanish Radio: A Preliminary Study of the Program Las Mañanas on RNE     

Flávia Gomes-Franco e Silva  Juliana Colussi  Paula Melani Rocha 《Journal of Radio & Audio Media》2018,25(1):77-91

This study was conducted in an environment of widespread use of social media and mobile applications in the mass media. The general goal of the study was to analyze the use of WhatsApp in cybermedia, specifically in radio. A case study was proposed to examine the use of WhatsApp on the program Las mañanas de RNE, broadcast by Spanish National Radio. It was found that the public was very accepting of the program’s initiative to solicit WhatsApp voice messages, beginning in November 2015. The case study used audio files of a direct broadcast that included specific times for audience participation. The use of WhatsApp was accepted by the audience, in addition to the use of the conventional telephone, as a tool well-suited to listener participation in radio programming. Finally, the study highlights the importance of interactive, participatory spaces in broadcasts through the creation of synergies with new forms of online participation.  相似文献   

Improving cognitive and physical function through 12-weeks of resistance training in older adults: Randomized controlled trial     

Paulo Ricardo Pereira Dos Santos  Bruno Remígio Cavalcante  Andreya Karolyne Dos Santos Vieira  Marcos Duarte Guimarães  Antônio Marconi Leandro Da Silva  Anderson Da Costa Armstrong 《Journal of sports sciences》2020,38(17):1936-1942

ABSTRACT

We performed a randomized, controlled trial to analyse the effects of resistance training (RT) on cognitive and physical function among older adults. Fifty participants (mean age 67 years, ~60% woman) were randomly assigned to an RT program or a control group. Participants allocated to RT performed three sets of 10-15RM in nine exercises, three times per week, for 12-weeks. Control group did not perform any exercise. Variables included cognitive (global and executive function) and physical function (gait, mobility and strength) outcomes. At completion of the intervention, RT was shown to have significantly mitigated the drop in selective attention and conflict resolution performance (Stroop test: -494.6; 95%CI: -883.1; ?106.1) and promoted a significant improvement in working memory (digit span forward: -0.6; 95%CI: ?1.0; ?0.1 and forward minus backward: -0.9; 95% CI: ?1.6; ?0.2) and verbal fluency (animal naming: +1.4, 95%CI 0.3, 2.5). No significant between-group differences were observed for other cognitive outcomes. Regarding physical function, at completion of the intervention, the RT group demonstrated improved fast-pace gait performance (?0.3; 95% CI: ?0.6; ?0.0) and 1-RM (+21.4 kg; 95%CI: 16.6; 26.2). No significant between-group differences were observed for other mobility-related outcomes. In conclusion, RT improves cognitive and physical function of older adults.  相似文献   

The effect of smartphones and playing video games on decision-making in soccer players: A crossover and randomised study     

Leonardo S. Fortes  Dalton De Lima-Junior  Lenamar Fiorese  José R. A. Nascimento-Júnior  Arnaldo L. Mortatti  Maria E. C. Ferreira 《Journal of sports sciences》2020,38(5):552-558

ABSTRACT

The objective of this study was to analyse the effect of the use of social networks in smartphones or playing video games on the passing decision-making performance in professional soccer athletes. Participants were 25 male professional soccer athletes (mean ± SD: age 23.4 ± 2.8 years). The participants performed three randomised conditions divided into three groups: control (CON), smartphone (SMA), and video game (VID). Before and after each experimental condition, the Stroop Task assessed the level of induced mental fatigue. Then, the athletes performed a simulated soccer match. A CANON® camera recorded the matches for further analysis on passing decision-making performance. A group effect was identified (p < .01) with impairment on passing decision-making performance for the SMA (p = .01, ES = 0.5) and VID (p = .01, ES = 0.5) conditions. We concluded that the use of social networks on smartphones and/or playing video games right before official soccer matches might impair the passing decision-making performance in professional soccer athletes.  相似文献