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81.
River restoration success: a question of perception 总被引:1,自引:0,他引:1
J?hnig SC Lorenz AW Hering D Antons C Sundermann A Jedicke E Haase P 《Ecological applications》2011,21(6):2007-2015
What defines success and failure of river restoration measures is a strongly debated topic in restoration science, but standardized approaches to evaluate either are still not available. The debate is usually centered on measurable parameters, which adhere to scientific objectivity. More subjective aspects, such as landscape aesthetics or recreational value, are usually left out, although they play an important role in the perception and communication of restoration success. In this paper, we show that different perceptions of restoration success exist by analyzing data from 26 river restoration measures in Germany. We addressed both objective parameters, such as hydromorphological changes and changes in fish and benthic invertebrate assemblages, from field investigations, and subjective parameters, such as opinions and perceptions, from water managers via an online survey. With regard to the objective hydromorphological and biotic parameters, our results agree with many studies that have reported improvements in the hydromorphology following restoration; however, there is no similar agreement between results concerning changes in the benthic invertebrate and fish assemblages. The objective results do not correspond to the subjective parameters because self-evaluation of the restoration projects by water managers was overly positive. Indeed, 40% of the respondents admitted that their evaluation was based on gut feeling, and only 45% of the restoration measures were monitored or occasionally checked. This lack of objectively recorded data meant that the water managers were not able to reasonably evaluate restoration success. In contrast, some self-evaluation responses reflected a different perception of the restoration success that was based on landscape aesthetic values or on benefit for the public; others adopted a general "condemned to success" attitude. Based on our data, we argue (1) that goals should be thoughtfully formulated prior to restoration implementation and (2) that it is necessary to monitor river restoration success from different perspectives. 相似文献
82.
Skoglind-?hman I Kjellberg K 《International journal of occupational safety and ergonomics》2011,17(4):433-444
The aim of this pilot study was to explore whether home care service personnel used knowledge and skills in transfer technique in their daily work; knowledge and skills gained by participating in training programmes, and to identify factors that may hinder and support their use. Focus group interviews were held with 2 home care service groups in 2 Swedish towns. Individual interviews were conducted with the personnel's managers, unit leaders and safety representatives. Qualitative content analysis was used. The findings revealed that the personnel tried to use their knowledge and skills. However, there were both hindering and supporting factors for the use of safe work technique. The findings indicate that training programmes in transfer technique should not be implemented as isolated actions without considering the physical environment, the wishes of persons receiving care and their relatives, the work organisation, the safety culture and the role of managers. 相似文献
83.
随着信息技术与传统安全防范技术的日益整合,要成为一个安全专家也变得越来越难了:因为他们必须要同时精通这两个领域的知识才行。 相似文献
84.
85.
在信号传输领域,同轴电缆、无线传输、双绞线等技术都占有一席之地,每种技术也都有其自身与生俱来的优点和缺点。除了上述的几种传输方式之外,还有一种正在变得越来越普及的技术,那就是光纤传输。 光纤传输是一种依靠光端机(包括发射端和接收端)将光纤线路连接起来,从而实现数据传输的方式。它有如下几个优点: 相似文献
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87.
利用生理毒物代谢动力学(PBTK)对小鼠静脉注射农药氰戊菊酯后,氰戊菊酯在体内分布转化代谢过程进行模拟,为评价农药暴露风险提供依据。小鼠静脉注射氰戊菊酯的PBTK模型构建分为5个房室:肝脏、肺、肾脏、充分灌注室和不充分灌注室,各房室内氰戊菊酯的浓度变化率由质量守恒微分方程表示。根据欧拉数值计算方法,对小鼠静脉注射氰戊菊酯后的毒物代谢动力学数据进行模拟。结果模拟预测了小鼠静脉注射0.5 mg·kg-1、2.5 mg·kg-1、10 mg·kg-1氰戊菊酯后血液、肝脏和肺中氰戊菊酯浓度变化曲线。为验证该模型的准确性,对小鼠静脉注射0.77 mg·kg-1氰戊菊酯后血液、肝脏和肺中氰戊菊酯的浓度值变化模拟值与前人的实验测量值进行比较,结果显示模拟值与实验值之间不存在显著性差异。因此利用该方法可以估测小鼠静脉注射氰戊菊酯的毒物代谢动力学数据,为评估农药暴露体内剂量数据提供了便利途径。 相似文献
88.
基于变异系数-综合指数法的乌鲁木齐城市脆弱性评价 总被引:1,自引:0,他引:1
从生态环境、经济和社会脆弱性三个方面,筛选新疆乌鲁木齐城市2006—2015年近十年的34个具体评价指标建立了城市脆弱性评价指标体系,通过对指标数据进行标准化处理后,以变异系数法确定各指标的权重,并运用综合指数法对乌鲁木齐城市脆弱性进行了综合评价。结果表明:伴随着经济的快速发展,乌鲁木齐城市综合脆弱性逐渐降低,但长时间处于中等偏高状态;虽然经济、社会和生态环境的综合脆弱性指数都呈下降趋势,但生态环境与经济和社会发展不协调,以牺牲环境为代价从而获得经济发展的粗放型经济发展模式仍然存在。据此有针对性地提出了有利于乌鲁木齐城市未来发展的经济、社会与生态环境相协调的经济增长模式。 相似文献
89.
Mountain lakes are usually sensitive to the effects of global and regional environmental changes. Since the second half of the 20th century, surface-water acidification has become a significant ecological problem, and many lakes in Europe and North America have anthropogenically acidified. Additionally, following reduction in emissions of sulfur (S) and nitrogen (N) compounds, recovery from acidification has been observed in many lakes. In this study, we used changes in diatom communities to reconstruct the pH histories based on changes recorded in nine Tatra lakes (Western Carpathians, Poland) since approximately 1850 AD. Overall, results indicate that acidic precipitation had little influence on lake-water pH in the Tatra Mountain lakes. Changes in diatom-inferred pH (DI-pH) generally were small and showed little evidence of acidification during the time of the highest air pollution (since the 1960s), and have shown little change since the reduction of acidic deposition since the 1990s. Lakes that showed some evidence of acidification included dystrophic lakes with low acid neutralizing capacity. However, as illustrated by the PCA trajectories of the diatom assemblages, the majority of the lakes currently contain diatom assemblages that are unlike the diatom floras that existed ca. 1850. 相似文献
90.
自从2003年中国开始成为世界上仅次于美国的世界第二大石油消费国,石油需求量随着国民经济的快速增长急剧攀升,供需缺口逐年加大.面对国际油价的风云变幻和国内石油市场的进一步放开,石油格局的变动对中国的经济、政治和军事安全带来了了巨大隐患.2007年8月2日,因为美国将原本单纯的商业操作"泛政治化",我国迄今为止规模最大的海外竞购--中国海洋石油有限公司收购尤尼科的失败事件,无不引发我们对中国石油安全战略的深沉思考.鉴于此,本文论述了确立中国石油安全战略的紧迫性和实现中国石油安全战略的途径. 相似文献