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青藏高原冻土区灌注桩入模温度对地温场的影响分析 被引量:12
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作者 吴亚平 郭春香 +2 位作者 赵世运 张鲁新 朱元林 《铁道学报》 EI CAS CSCD 北大核心 2004年第6期81-85,共5页
以热传导理论为基础建立了冻土区单桩地温场的热分析模型,然后以青藏高原清水河某地段夏季施工为条件,考虑实际气温和地温的初始条件,用有限元方法计算了混凝土入模温度从5℃提高到12℃时桩周地温场的变化,分析提高混凝土入模温度对桩... 以热传导理论为基础建立了冻土区单桩地温场的热分析模型,然后以青藏高原清水河某地段夏季施工为条件,考虑实际气温和地温的初始条件,用有限元方法计算了混凝土入模温度从5℃提高到12℃时桩周地温场的变化,分析提高混凝土入模温度对桩的自然回冻时间及施工进度可能造成的影响,所得结论可为冻土区钻孔灌注桩施工进度安排提供参考。 展开更多
关键词 青藏高原 多年冻土区 钻孔灌注桩 人模温度 地温场
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北方桥梁大体积混凝土冬季施工
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作者 于茜 苏晔 侯克君 《城市道桥与防洪》 2007年第2期59-62,共4页
沈阳市老道口大桥为独塔单索面斜拉桥,该文介绍了在该桥主塔基础混凝土冬季施工中如何控制混凝土的入模温度和承台周边环境温度以及如何控制混凝土养护期间的温度梯度的关键要点,并提出了实施中的主要技术措施。
关键词 斜拉桥 主塔墩承台 冬季施工 人模温度 环境温度 温度梯度 技术措施 沈阳市
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ON THE DESIGN OF A NEW HUMAN COMFORT INDEX 被引量:2
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作者 冯业荣 王安宇 林镇国 《Journal of Tropical Meteorology》 SCIE 2004年第1期106-112,共7页
In designing the human comfort index (CI) used in Guangzhou, a Gaussian curve was adopted as the fundamental profile to develop a traw hat?model of comfort index. The model projects low or high temperatures into low i... In designing the human comfort index (CI) used in Guangzhou, a Gaussian curve was adopted as the fundamental profile to develop a traw hat?model of comfort index. The model projects low or high temperatures into low index values and the moderate temperatures into high index values. Air temperature was chosen as a basic factor in the model. Other factors such as humidity, sunshine and wind speed were introduced by considering them as temperature departures to an equivalent apparent temperature (EAT). Since the index is a relative index, 25C was chosen as an ideal apparent temperature (the most comfortable state) and a maximum CI value of 100 was assigned at this temperature. While in other circumstances, the index would be lower than 100. By utilizing this model, the daily comfort index values had been calculated for Guangzhou city for 1998-1999, using mean temperature, mean humidity, mean wind speed and total hours of sunshine. Results show that the new model was reasonable and practicable. Not only could it reflect the monthly variation of human comfort in Guangzhou, but also was sensitive to short-term changes of weather conditions. 展开更多
关键词 equivalent apparent temperature (EAT) human comfort index (CI) Gaussian function
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What Do Cattle Prefer in a Tropical Climate: Water Immersion or Artificial Shade?
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作者 Ana Carina Alves Pereira de Mira Geraldo Alfredo Manuel Franco Pereira +1 位作者 Cristiane Gonqalves Titto Evaldo Antonio Lencioni Titto 《Journal of Life Sciences》 2012年第12期1356-1362,共7页
Animal performance is affected by high air temperature and it is known that shade reduces the absorption of radiant temperature, and water for immersion facilitates heat loss. This study intends to find preferences of... Animal performance is affected by high air temperature and it is known that shade reduces the absorption of radiant temperature, and water for immersion facilitates heat loss. This study intends to find preferences of resources that contribute for the well-being of cattle and how they alterdaily behaviour. During summer, six Caracu and six Red Angus bulls were submitted to two different treatments: availability of artificial shade and water for immersion and availability of water for immersion. The categories observed were: positions (in the sun, under the shade, in the water), posture (standing, lying down) and activities (grazing, ruminating leisure). The behavioural patterns were recorded using the focal sampling method every 15 minutes (from 6:00 a.m. to 6:00 p.m.). When shade and water for immersion coexists, cattle in this study prefer shade to avoid solar radiation. Both breeds had remained more time grazing, followed by ruminating in the Caracu breed, and by resting in the Red Angus breed. The Caracu breed had presented clear preference for the shade resource, but that fact was not always observed in the Red Angus breed. In hot climates, resources for defence against heat load, as shade and water for immersion improve the well-being of cattle. 展开更多
关键词 Animal welfare behaviour GRAZING Caracu Red Angus.
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Two-dimensional finite element model to study temperature distribution in peripheral regions of extended spherical human organs involving uniformly perfused tumors 被引量:1
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作者 Akshara Makrariya Neeru Adlakha 《International Journal of Biomathematics》 2015年第6期57-86,共30页
Temperature as an indicator of tissue response is widely used in clinical applications. In view of above a problem of temperature distribution in peripheral regions of extended spherical organs of a human body like, h... Temperature as an indicator of tissue response is widely used in clinical applications. In view of above a problem of temperature distribution in peripheral regions of extended spherical organs of a human body like, human breast involving uniformly perfused tumor is investigated in this paper. The human breast is assumed to be spherical in shape with upper hemisphere projecting out from the trunk of the body and lower hemisphere is considered to be a part of the body core. The outer surface of the breast is assumed to be exposed to the environment from where the heat loss takes place by conduction, convection, radiation and evaporation. The heat transfer from core to the surface takes place by thermal conduction and blood perfusion. Also metabolic activity takes place at different rates in different layers of the breast. An elliptical-shaped tumor is assumed to be present in the dermis region of human breast. A finite element model is developed for a two-dimensional steady state case incorporating the important parameters like blood flow, metabolic activity and thermal conductivity. The triangular ring elements are employed to discretize the region. Appropriate boundary conditions are framed using biophysical conditions. The numerical results are used to study the effect of tumor on temperature distribution in the region. 展开更多
关键词 Thermal conductivity triangular ring element uniformly perfused tumor metabolic heat generation.
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