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   

人体惯性参数的实测生物力学研究   总被引：3，自引：0，他引：3  

纪仲秋  姜桂萍  郎雪梅 《北京体育大学学报》2001,24(3):329-331

人体惯性参数是进行生物力学分析、人类工程学等工作时均需要的人体基本参数。通过活体的实际测量 ,比较中国人体惯性参数和国外人体惯性参数所计算人体总重心位置的差异 ,经统计学数据处理来验证中国人体惯性参数的可靠性 ,研究表明 :中国人体惯性参数比国外人体惯性参数更加适应中国情况 ,应对中国人体惯性参数推广应用  相似文献   

滚翻垫球后“再后倒”现象的讨论     

王凤玲 《石家庄学院学报》2000,(4)

对滚翻垫球后“再后倒”现象进行理论分析 ,可找出出现问题的根源 ,以便在教学中解决这一问题  相似文献   

论刚体对坐标轴转动惯量的平移和旋转变换     

于志明 《洛阳师范学院学报》2007,26(5):50-52

本文导出了刚体对坐标轴的转动惯量的平移和旋转变换一般式。  相似文献   

陈序经的东西文化观新论     

李华丽 《五邑大学学报(社会科学版)》2011,13(1):26-28,92

陈序经的文化观是他全盘西化论的理论基石。陈序经认为“文化是人类适应环境时代,以满足其生活的努力的结果和工具”,他还强调文化的世界性和中国文化的惰性。从文化的定义、文化的世界性、文化的惰性三方面对陈序经东西文化观进行考察,才能够真正理解其内心的苦衷,澄清人们的误解。  相似文献   

单自由度体系频率分析的教学探究     

金建洲  樊友景 《焦作大学学报》2010,24(3):92-93

各质点惯性力不共线的单自由度体系的频率分析,是结构动力学教学中的一个难点。文章利用理论力学中的知识,将单自由度质点系平动时的频率计算公式ω=1/（mδ）推广到了单自由度质点系转动时的的频率计算问题,并给出了相应的转动柔度系数的确定方法。这样的处理也启发了学生将各门课程的知识进行融会贯通。  相似文献   

The influence of moment of inertia on baseball/softball bat swing speed   总被引：1，自引：1，他引：0  

Keith?KoenigEmail author  Nan?Davis?Mitchell  Thomas?E.?Hannigan  J.?Keith?Clutter 《Sports Engineering》2004,7(2):105-117

The speed at which a player can swing a bat is central to the games of baseball and softball, determining, to a large extent, the hit speed of the ball. Experimental and analytical studies of bat swing speed were conducted with particular emphasis on the influence of bat moment of inertia on swing speed. Two distinct sets of experiments measured the swing speed of colege baseball and fast-pitch softball players using weighted rods and modified bats. The swing targets included flexible targets, balls on a tee and machine pitched balls. Internal mass alterations provided a range of inertial properties. The average measured speeds, from 22 to 31 m s⁻¹, are consistent with previous studies. Bat speed approximately correlates with the moment of inertia of the bat about a vertical axis of rotation through the batter's body, the speed generally decreasing as this moment of inertia increases. The analytical model assumes pure rotation of the batter/bat system about a vertical axis through the batter's body. Aerodynamic drag of the batter's arms and the bat is included in the model. The independent variable is bat moment of inertia about the rotation axis. There is reasonable agreement between the model and the measured speeds. Detailed differences between the two suggest the importance of additional degrees of freedom in determining swing speed.  相似文献   

三线扭摆法测刚体转动惯量所用近似方法的分析   总被引：1，自引：0，他引：1  

陈文清  陈林峰 《洛阳工业高等专科学校学报》2004,14(3):20-22

分析在推导转动惯量的测量公式时采用的近似方法和其对测量结果带来的影响，指出减小其影响的途径。  相似文献   

网民政策态度形成机制研究——从"网议宁波"说起   总被引：2，自引：0，他引：2  

陈姣娥  王国华 《中国软科学》2010,(5)

近期,网民对一些公共政策多持否定态度,本文所引用的宁波公务员错时工作政策的案例即是如此.网民认为该政策是对公务员"新的隐形福利",公务员则认为是公众误读政策.本文运用扎根理论,通过分析网民的网上投票和评论帖,归纳出以网民为代表的公众政策态度形成机制;并采用社会分层理论和相对剥夺理论揭示形成这种政策"误读"的深层原因,提出"政策认知定势"和"政策沉淀"概念,以解释特定政策背景下公众对政策的认知模式.  相似文献   

动态环境下组织冗余对企业探索的影响研究          下载免费PDF全文

赵亚普  张文红  陈斯蕾 《科研管理》2014,35(2):10-16

以往学者往往关注组织冗余对企业绩效的最终影响,而对更为微观的企业探索的影响关注的较少。本文基于资源基础理论和惰性理论,以中国187个高科技制造企业为研究对象,检验了组织冗余与企业探索之间的关系。研究发现:(1)组织冗余对企业探索有显著的积极影响;(2)环境动态性对上述关系具有显著的负向调节作用。这一结果表明单一的理论视角难以全面解释组织冗余对企业探索的影响,将资源基础理论和惰性理论结合起来能增进我们对这一现象的理解。  相似文献