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111.
The big flood in the upper Elbe River catchment area has revealed a wide spectrum of problems with contaminated sediments. So far, an effective strategy for managing contaminated sediments on a river basin scale is still missing and it seems that not much has been learned from the lessons received during the last decade. In the following overview, special emphasis is given to the utilization of geochemically-based techniques for sediment remediation, which can be applied in different parts of a river basin. The examples presented here are mostly from the Elbe River catchment area. In general, new technical problem solutions need a set of practical process knowledge that uses a wide range of simulation techniques, as well as models in different spatial and temporal scales. The evaluation of recent flood events clearly demonstrates the importance of chemical expertise in the decision-making process for the sustainable development in river basins. 相似文献
112.
活性炭纤维吸附-催化燃烧装置处理有机废气 总被引:6,自引:1,他引:6
介绍一种处理有机废气的吸附-催化燃烧新型装置,以活性炭纤维为吸附剂,结合多单元分流组合式中附床,采用PLC电脑来实现整个系统的连续运行。实验运行结果表明,对于处理大风量,低浓度的有机废气,该技术与其他技术相比具有净化效率高,节能降耗,自动化水平高等优点。 相似文献
113.
114.
Among both forest practitioners and the general public, “forest health” has become an issue of contention. Whereas the debate
over which treatments will best achieve healthy forests has been framed largely by the popular media and politicians as a
struggle between industry and environmentalists, the views of the general public remain unexplored. Survey results from Oregon
and Washington residents were used to assess the relationships between respondents’ self-described environmental or economic
priorities and the following two variables: (1) acceptability of forest management practices and (2) perceived threats to
forest health. Findings indicate that active management was generally accepted by a majority of respondents regardless of
their environmental or economic orientation. Disagreement emerged, however, when the appropriateness of specific management
practices within specific forest conditions was examined. Additionally, strong evidence was found for a relationship between
self-described environmental or economic orientation and perceived threats to forest health. Those with an environmentally
oriented viewpoint tended to perceive human-caused factors as the largest threats, whereas those with an economic orientation
saw naturally occurring processes as the greatest threats. These findings suggest that the issue of contention is not active
management per se. Rather, the major divisions in the forest health debate are defined by specific contexts and circumstances,
as well as the management practices used. 相似文献
115.
MapObjects在城市道路交通噪声管理中的应用 总被引:6,自引:0,他引:6
从Visual Basic控件技术出发,介绍了建立在对象链接与嵌入技术基础上由美国ESRI公司的采用GIS控件MapObjects的运行机制及特点。结合该控件在城市道路交通噪声信息管理系统开发中的应用,对系统的建设目标、结构及开发模式做了介绍;以对北京市道路交通噪声信息管理系统的开发为例,对系统的功能作了简要说明。 相似文献
116.
讨论了城市污水经过A/O工艺处理时活性污泥的二次污染问题。所采用的方法是将原水、处理后的出水及活性污泥用乙酸丁酯萃取、萃取相经过真空浓缩后,采用GC/MS测定了样品中的有机化合物。结果表明,在A/O工艺处理城市污水过程中,活性污泥的吸附作用是主要的,降解作用是次要的:A/O工艺所排放的活性污泥仍然是一种危险的污染物。 相似文献
117.
介绍了大气污染生物主动监测中监测植物的选择原则:适宜的监测方法;合适的监测时间及监测植物的标准化问题。讨论了监测中应注意的几个问题如放样点距地在及排放点的合适距离。在监测中植物的朋肥供应等,并介绍了自掣是简易植物计。 相似文献
118.
浅谈环境噪声标准存在的问题与修订要点 总被引:2,自引:0,他引:2
在提出目前国家有关噪声标准中存在一些问题的同时,指出噪声标准修订工作的紧迫性及修订要点。 相似文献
119.
Frequency versus time lost measures of absenteeism: Is the voluntariness distinction an urban legend? 下载免费PDF全文
We investigate a long‐standing methodological rule of thumb, the idea that the frequency of absenteeism from work approximates an expression of voluntary behavior while total time lost better reflects involuntary behavior and ill health. Conducting original meta‐analyses and using results from existing meta‐analyses, we determine that time lost and frequency are equally reliable, that the relationship between them approximates unity when corrections for measurement artifacts are applied, and that there is very little evidence for differential criterion‐related validity predicated on the voluntariness distinction. We supply new meta‐analytic estimates of the reliability of absenteeism adjusted for aggregation period and determine that most extant meta‐analyses of the correlates of absenteeism have markedly under‐corrected for unreliability. Our results question the basic construct validity of the time lost–frequency distinction, and they contradict the practice of using “trigger points” that factor absence frequency into attendance monitoring and associated discipline systems so as to discourage short‐term absenteeism, assumed to be volitional. We conclude that the idea that time lost and frequency reflect different degrees of voluntariness is an unsupported urban research legend. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
120.
阐述了氡的来源、在环境中的分布状况及其对人体的危害。用主动式活性炭盒采样和高纯锗探测器伽玛射线谱仪对样品进行测量,具有灵敏度高、精度好、易于操作等特点。 相似文献