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791.
Trevor C. Hughes 《Journal of the American Water Resources Association》1984,20(5):739-746
Although the volume of potable water used at recreation developments is minor relative to total regional water use, very high quality is required and the source is often of limited capacity, such as a mountain spring or small local aquifer. Frequent confrontations between developers and regulatory agencies result from claims by developers that water demand will be very small while regulators tend to treat such developments the same as municipal residence. Almost no published data base exists for resolving such conflicts. Included here are: 1) Water use measurements of various peak period durations (seasonal, monthly, daily, and instantaneous) at several types of recreational developments in Utah and Wyoming (mountain cabins, both ski- and water-based condominiums, and recreation vehicle campgrounds), 2) statistical (frequency) analysis of the data and a comparison with municipal demands in the same region, and 3) analysis of occupancy rates at the various categories of developments. 相似文献
792.
Biodiversity surveys are often hampered by the inability tocontrol extraneous sources of variability introduced intocomparisons of populations across a heterogenous landscape. If not specifically accounted for a priori, this noisecan weaken comparisons between sites, and can make itdifficult to draw inferences about specific ecologicalprocesses. We developed a terrain-based, paired-sitesampling design to analyze differences in aquaticbiodiversity between streams draining eastern hemlock (Tsuga canadensis) forests, and those draining mixedhardwood forests in Delaware Water Gap National RecreationArea (USA). The goal of this design was to minimize variancedue to terrain influences on stream communities, whilerepresenting the range of hemlock dominated streamenvironments present in the park. We used geographicinformation systems (GIS) and cluster analysis to define andpartition hemlock dominated streams into terrain types basedon topographic variables and stream order. We computedsimilarity of forest stands within terrain types and usedthis information to pair hemlock-dominated streams withhardwood counterparts prior to sampling. We evaluated theeffectiveness of the design through power analysis and foundthat power to detect differences in aquatic invertebratetaxa richness was highest when sites were paired and terraintype was included as a factor in the analysis. Precision ofthe estimated difference in mean richness was nearly doubledusing the terrain-based, paired site design in comparison toother evaluated designs. Use of this method allowed us tosample stream communities representative of park-wide forestconditions while effectively controlling for landscapevariability. 相似文献
793.
This study investigated Taiwan's industries to identify the characteristics of companies most advanced in environmental design. Thirty design principles in five categories were used to define advanced environmental design. The five categories are: use of raw materials, use of energy, design for recyclability, product life cycle assessment, and packaging optimization. We found that of the 30 design principles only eight were applied consistently by Taiwanese manufacturers. Most effort was given to the “use of energy” category. The most advanced environmental design was found at large companies—those with over 2000 employees, 3 billion in capital, and/or 3 billion in annual sales. 相似文献
794.
发展绿色流通是我国城市治理环境污染的新路径,也是一种既经济又高效的治污新举措。但目前发展城市绿色流通面临着诸多问题,需要树立绿色流通理念,实施绿色经营战略,强化流通企业责任,加快物流社会化建设,加大政府支持力度。 相似文献
795.
由于农业大量使用化学品 ,使农产品的农药残留量及其衍生物增加 ,从而对人体健康造成具大的危害性。本文的主要目的就是让人们进一步认识在农产品生产中使用农用化学品的危害 ,倡导我国农业走绿色农产品生产的道路 相似文献
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梁腹板开圆孔的钢框架抗震节点 总被引:11,自引:1,他引:11
杨庆山 《中国安全科学学报》2005,15(2):45-50,40
介绍了梁腹板开圆孔的钢框架梁柱节点 ,笔者探讨的基本思路是希望通过对梁截面的削弱确保结构在强震作用时的塑性铰远离节点域而出现在梁上 ;同时 ,该节点形式应用于住宅体系时 ,使水暖管线穿梁和降低结构空间占用成为可能。因此 ,笔者对该节点形式的基本受力性能及设计中需要考虑的构造措施进行了较详细的探讨 ,并利用ANSYS对其塑性区分布和剪应力分布进行了分析。研究结果初步表明 ,梁腹板开圆孔的钢框架节点具有理论上的合理性和实用上的可行性 ,可达到塑性铰外移和增加使用功能的目的。 相似文献
800.
大规模客流对我国各大城市铁路车站旅客的安全潜伏着极大的隐患,车站旅客安全保障体系的建设显得十分重要。分析在大规模客流条件下,车站旅客可能发生的主要安全问题,包括拥挤踩踏、灾害、公共卫生、犯罪、自身发病等意外事件;提出建立旅客安全保障体系的层次结构,研究了旅客安全保障体系的流程;从车站客流组织和管理角度、车站设计角度、服务设施角度等方面来研究大规模客流条件下车站安全保障工作中应采取的措施。保障旅客安全是车站工作的重点,必须通过科学的手段,从各方面综合、严密地进行管理和组织,才能实现铁路车站的安全运营。 相似文献