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531.
水足迹分析理论与方法 总被引:5,自引:0,他引:5
水资源危机已成为全球可持续发展的一个日益突出的问题。为创新水资源问题的研究思路和完善水资源管理,引进了国际水资源领域较先进的水足迹分析法,系统地介绍了水足迹分析法的基本理论和计算方法,并计算了世界20个国家和地区的水足迹。结果表明,大部分国家水足迹过高、水资源压力过大,虚拟水贸易增加、水进口依赖明显。最后分析了产生高水足迹的原因,提出了降低水足迹的措施,并对该方法及其应用前景进行了评价。 相似文献
532.
高职高专院校公共选修课程体系探究 总被引:2,自引:0,他引:2
针对一些高职高专院校重技能、轻人文而导致公共选修课建设甚至缺失的现象,对公共选修课程体系建构在目标、内容方面作了详细阐述,并对课程类型的设置、开设年级和课时比例设置提出了建议。 相似文献
533.
Ahlstrom U 《Journal of Safety Research》2005,36(2):159-169
INTRODUCTION: Adverse weather conditions have a major impact on National Airspace System (NAS) operations. They create safety hazards for pilots, constrain the usable airspace for air traffic control (ATC), and reduce the overall capacity of the NAS. A system-wide dissemination of weather information to controllers could theoretically improve safety and efficiency. PROBLEM: However, it is currently unclear what weather information would be beneficial for tactical operations. Furthermore, no previous research has empirically evaluated optimal presentation designs for ATC weather displays. Ill-designed weather displays can cause safety hazards by presenting redundant information (i.e., by increasing the cognitive load) and display clutter (e.g., by interfering with the visual extraction of traffic data). METHOD: In the present paper, we outline our use of cognitive work analysis (CWA) techniques for the assessment of weather information needs for terminal controllers. RESULTS: Specifically, we describe how the CWA modeling tools helped us reveal instances in the terminal domain where weather information is lacking or insufficiently disseminated. We used our CWA results to drive the development of weather display concepts and to set up a high-fidelity simulation capability. IMPACT ON INDUSTRY: By means of high-fidelity simulations, we can empirically evaluate controller weather information needs in order to propose weather displays for increased aircraft safety and efficiency of terminal operations. 相似文献
534.
退耕还林与贫困地区粮食安全的实证分析--以宁夏回族自治区为例 总被引:11,自引:0,他引:11
本文以实证分析的方法,以宁夏地区为例,通过研究该地区2003年200户退耕户和100户非退耕户之间。以及二者与1999年实行退耕还林政策前的人均粮食消费量和人均食品支出水平的变化,认为退耕户的粮食安全程度比非退耕户和退耕前的农户有了显著的提高,这种提高与农民的人均收入水平和人均耕地面积呈正相关,而与粮食播种面积比重呈负相关,因而可得得出结论:在生态脆弱地区实行退耕还林政策并不会影响当地农民的粮食安全。 相似文献
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537.
色牢度是有色纺织品的重要考核指标,单项色牢度往往不能真实反映出纺织品在实际使用时的真实牢度,有时各种单项牢度指标都很好,而在实际穿着或使用时仍会出现问题。本方法标准是在试验室中人工模拟有色纺织品在人体穿用及自然气候等复杂条件下,于短期内(2-4天),可预测出在不同纬度地区实际穿着一定时间后颜色的变化情况。本方法不仅适用于军用纺织品,同样也适用于民用所有有色纺织品。可依据用户的不同要求,确定试验周期,来反映某一地区一个阶段后颜色变化的真实情况。还可为纺织印染行业的工艺设计及染料选择,提供综合,快速,准确,科学有效的检测方法。 相似文献
538.
Edwin D. Bailey 《Journal of the American Water Resources Association》1979,15(3):801-811
ABSTRACT: The Tucson area is totally dependent on ground water, which is in increasingly short supply due to excessive overdrafts. Tucson area waste water treatment plants discharge material quantities of secondary effluent downstream, which is lost to evapotranspiration and recharge of the ground water basin. The city and the four large mining companies who share the common Santa Cruz basin ground water, recognized the common water supply problem and agreed to fund a feasibility study for mining process use of the effluent to partly alleviate the overdraft of ground water. The study analyzed the projected waste water effluent resources, potential mining company demand for waste water effluent and possible interface of an effluent delivery facility with the proposed Central Arizona Project. The effluent resources were analyzed with respect to potential demand. An optimum alignment was selected. An optimum system was detailed through design schematics, amortized cost and finance requirements, and an implementation schedule. It was concluded that a waste water effluent delivery facility could be implemented which would utilize reclaimed effluent in quantities approximating 35 percent of basin overdraft and which would provide revenue for full cost recovery over a 20 year operation period. The mining companies are studying the internal economic impacts of the project. 相似文献
539.
Donald E. Agthe Dennis L. Larson 《Journal of the American Water Resources Association》1980,16(6):1080-1083
ABSTRACT: The problem of nonmatching irrigation and solar power production seasons creates the problem of what to do with the surplus power. The economic law of opportunity cost dictates that substitution for currently commercially purchased power is the best use for this power. This law also allows for new power using enterprises that satisfy specific criteria to be used on the farm before sale of the residual to a local public utility can be considered. Economic and Financial Evaluation of the solar powered irrigation system show that the price of commercially purchased power must reach 9.5 cents per Kwh before the system is feasible under the ideal assumption of complete use of the residual power to substitute for commercially purchased power. 相似文献
540.
On November 13-14, 2003, a symposium on high-visibility safety belt use enforcement in Raleigh, NC: (a) celebrated the 10th anniversary of North Carolina's Click It or Ticket program; (b) documented current knowledge regarding safety belt use; (c) proposed strategies to increase use further; and (d) discussed research to support these strategies. 相似文献