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971.
972.
针对非均匀热环境下乘员热舒适性的评价问题,提出当量温度评价指标(EQT)和当量均匀温度评价指标(EHT);完成这两种评价指标的关键技术在于如何进行流场的三维Navier-Stokes方程与人体的生物热方程之间的耦合迭代。在进行数值计算时发现:流场计算时人体皮肤表面给温度分布(即提D irichlet问题)、人体的生物热方程求解时给热流密度分布(即提Neumann问题),采用其边界条件的提法后,使得非均匀热环境下的流场与人体生物热方程之间的大迭代容易收敛和稳定。典型算例表明:对同一种物理问题,尽管两种评价下所得到的当量温度不同,但得出的评价效果是一致的,这就从侧面显示了这两种评价方法的一致性与有效性。 相似文献
973.
目的是模拟分析地铁火灾时不同行为特点中青年人群对疏散标识的决策反应。方法采用构建地铁站台火灾时烟气蔓延的三维空间模型,在中青年人群中进行应急疏散的仿真实验,利用统计分析软件SPSSv14.0对采集到的数据进行统计分析。结果得到性别、成长环境和专业背景等不同人员行为特点与疏散标识决策反应的相关性,并对疏散标识的字体、图案特性进行选优。得出结论,性别、成长环境和专业背景与人员对不同疏散标识的决策反应有一定的相关性。图形为主要设计元素的疏散标识是地铁站台火灾烟气条件下疏散人员的优先选择。 相似文献
974.
Waite L 《Disasters》2000,24(2):153-172
This research tries to reach an understanding of the well-being of female-headed household members through a comparison to male-headed household members in the collectives of the Suleimaniyah governorate in Iraqi Kurdistan. Research was undertaken in five collectives in Suleimaniyah during the summer of 1998. The research contributes to the current gender and development debates which are concerned with improving the understanding of the specific gendered forms of disadvantage faced by female-headed households rather than assuming the universal poverty of this group. An understanding of well-being is approached through a broad conceptualisation of vulnerability in preference to a narrow poverty definition. That the findings of this research are complex attests to the multi-dimensional and mutually constitutive gendered experiences of vulnerability. The definitive conclusion to emerge from this research is a refuting of the rhetoric-fuelled stereotype that households headed by women are at a disadvantage in all the dimensions of vulnerability in comparison to households headed by men. The research also establishes the methodological necessity of examining intra-household distributive mechanisms that determine individuals' well-being. 相似文献
975.
Harmonizing water management and social needs: a necessary condition for sustainable development. The case of Israel's coastal aquifer 总被引:3,自引:0,他引:3
This study focuses on the problem of most efficiently fulfilling the water requirements of society for sustainable water resources management. The goal is to coordinate effectively the social needs of the resident population with operational water resources management planning.The proposed approach consists of a pyramidal hierarchy of water resource management needs, similar to that suggested by psychologist Abraham Maslow for human social needs. The two pyramidal hierarchies can be simultaneously employed to delineate guidelines to synchronize planning for sustainable water resources development with the concerns and expectations of the resident population. In both hierarchies, higher level needs remain irrelevant and difficult to attain until lower level needs of the resident population have been fulfilled.Management planning measures employed with regard to Israel's coastal aquifer have been used to illustrate this approach. Observation of Israel's experience indicates markedly reduced effectiveness where such measures have failed to be properly synchronised with societal needs. Conversely, where hydrological management measures were successfully synchronized with societal concerns, increased efficiency towards attaining sustainable groundwater management was evident. 相似文献
976.
Dust Storm as an Environmental Problem in North China 总被引:5,自引:0,他引:5
Dust storms in north China, which are associated with land deterioration from increasing human pressures, have intensified over the past decades. Although synoptic meteorological conditions and sedimental environments dictate the occurrence of dust storms, their increase in frequency in north China due to human activities can be expected. Sand stabilization and control projects may be compromised by the pursuit of short-term economic returns and lack of systematic and integrated understanding of land degradation. Two actions are recommended as positive responses to escalating dust storms in north China. A policy of long-term ecologically sustainable development strategies is needed as well as a scientific research initiative combining biophysical and socioeconomic aspects. 相似文献
977.
978.
Natural factors and human modifications contribute to the estimated annual loss of 10,200 ha of coastal land in the Mississippi River Deltaic Plain Region of south Louisiana. This paper combines information on regional geology and human-induced habitat alterations to evaluate the relative importance of human and natural factors to marsh loss. Data on marsh area and habitat type for 139 7.5-min quadrangles were calculated from maps based on aerial photographs from 1955/56 and 1978, and data on regional geology obtained from published maps were used to construct multivariate model relating initial marsh area, change in urban and agricultural area, change in canal and spoil area, canal area in 1978, depth of sediment overlying the Prairie terrace, and subdelta age to marsh loss. The model indicated that between 25.0% and 39.0% of the marsh loss that occurred during the 23-year period was related to canal and spoil construction, and between 9.5% and 12.7% was related to urban and agricultural development. These are minimal estimates of loss because they do not include many secondary effects (for example, canal orientation, saltwater intrusion, and eutrophication) that can also result in indirect loss. Depth of sediment, initial marsh area, delta lobe age by 1978 canal and spoil area interaction, and indirect effects not included in the model accounted for remaining marsh loss. 相似文献
979.
980.
Niels Lind Desmond Hartford Hamed Assaf 《Journal of the American Water Resources Association》2004,40(1):89-96
ABSTRACT: Major loss of life can occur in a flood when people are toppled by floodwater currents. Three approximate mechanical models and two empirical models of the hydrodynamics of toppling are presented and calibrated to align with available experimental observations to assist the analysis of the risk of life loss. The mechanical models consider circular cylindrical, square cylindrical and cylindrical composite, heavy bodies assembled to represent a human immersed in a flow field and subject to drag and buoyancy forces. The models can account for the height and weight of the exposed persons, and the velocity and depth of the flow. The models are in good mutual agreement and, when calibrated, yield failure functions that can be used to calculate the probability of loss of stability. 相似文献