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131.
It is thought that young homing pigeons are able to use information acquired en route for their initial homeward orientation. However, the cues involved and mechanisms utilised are under discussion. Blocking light-dependent route-specific information during the first leg of an outward journey detour, together with analysis of pigeons that were raised under different loft conditions, allowed us to correctly evaluate the functioning of this mechanism and, more generally, the navigational map of birds. Pigeons from the same stock were raised and kept in two different lofts. The birds in the experimental groups were transported to the release sites via detours, and light-dependent information was denied during the first half of the outward journey (no compass information was available). Control birds were transported by the most direct route and had access to all available information. In general, the results showed that the low-loft birds preferred to use magnetic compass cues, whereas the high-loft birds preferred to use navigational map cues to collect information of the first part of the outward journey. The impairments observed in the homing performances of the experimental groups highlight the reliability of information collected inside the map area. Relevant to an understanding of the route-reversal mechanism was the evidence that this mechanism is able to function in the absence of compass information (birds raised in a wind-exposed loft show a detour effect). In systems where directional information could be provided by multiple sources, processing and extracting accurate course trajectories through a common mechanism may prove more efficient and reliable.  相似文献   
132.
随着人们环保意识的逐渐增强,航空业所造成的环境和噪声污染已经越来越成为令人关注的重大问题。从5个方面介绍了发达国家航空业发展循环经济的经验,指出我国作为发展中国家,要正视与发达国家的差距,借鉴国外先进经验,转变观念、大胆创新,大力发展循环经济,开辟我国航空业的新纪元。  相似文献   
133.
韩国《环境政策基本法》研究   总被引:1,自引:0,他引:1  
现行韩国《环境政策基本法》明确了可持续发展、环境权等基本理念,强化环境行政的综合调整机能,确立以事前预防为中心的环境政策,并随着时代发展要求及时进行多次修改,为最终实现其立法目的提供了制度保障。韩国环境基本法的成功经验,对我国《环境保护法》的修改具有一定借鉴价值。  相似文献   
134.
摘要:如何及时采取科学手段控制污染,减少对环境和人民生命财产的损失,与专家组的专业水平有着密切的关系。文章结合松花江硝基苯污染、化工原料桶进入江水事件,论述了在突发性环境污染事件中专家组的作用。  相似文献   
135.
郑磊  方祥洪  向纬琳 《四川环境》2014,33(5):115-119
近年来低、中水平放射性废物由于其数量大,种类多等特点得到了国际上越来越多的关注。近地表处置是这类放射性废物的主要处置技术。本文介绍了国外几个国家的近地表处置场运行情况以及管理经验。陈述了我国西北和北龙两个处置场设计及运行情况,对国内外低中放处置场的处置技术进行比较,借鉴国外近地表处置场的先进经验,提出我国近地表处置场建设的相关建议,为我国新建近地表处置场建设提供参考。  相似文献   
136.
With growing urban populations and climate change, urban flooding is an important global issue, even in dryland regions. Flood risk assessments are usually used to identify vulnerable locations and populations, flooding experience patterns, or levels of concern about flooding, but rarely are all of these approaches combined. Furthermore, the social dynamics of flood concerns, exposure, and experience are underexplored. We combined geographic and survey data on household‐level measures of flood experience, concern, and exposure in Utah's urbanizing Wasatch Front. We asked: (1) Are socially vulnerable groups more likely to be exposed to flood risk? (2) How common are flooding experiences among urban residents, and how are these experiences related to sociodemographic characteristics and exposure? and (3) How concerned are urban residents about flooding, and does concern vary by exposure, flood experience, and sociodemographic characteristics? Although floodplain residents were more likely to be White and have higher incomes, respondents who were of a racial/ethnic minority, were older, had less education, and were living in floodplains were more likely to report flood experiences and concern about flooding. Flood risk management approaches need to address social as well as physical sources of vulnerability to floods and recognize social sources of variation in flood experiences and concern.  相似文献   
137.
泥石流防治工程方案优化设计专家系统初步研究   总被引:6,自引:1,他引:6  
泥石流灾害是一种复杂的自然现象,泥石流物防治工程设计中不确定的因素很多,泥石流防治工程往往是根据泥石流防治专家自己的专业知识和经验来进行的,广泛收集,分析综合和抽取专家的知识和经验,采用专家系统是进行此类非结构化总是求解的主要途径之一。  相似文献   
138.
设计一种基于微试剂原位水质检测仪的多参数水质微型站监控系统。通过对水质检测流程合理分析以及各监控点反馈信号诊断,结合LabVIEW可视化编程技术、信号分析技术和测控技术,分别从硬件和软件方面,设计了一种基于多传感器数据融合的水质微型站监控感知的检测流程测控模型。现场应用结果表明,采用诊断专家系统的水质微型站监控系统满足水质测控的需求,极大提升系统的稳定性、安全性。  相似文献   
139.
To obtain comparable results of multi‐element analysis of plant materials by different laboratories, a harmonized sampling procedure for terrestrial and marine ecosystems is essential. The heterogeneous distribution of chemical elements in living organisms is influenced by different biological parameters. These parameters are mainly characterized by genetic predetermination, seasonal changes, edaphic and climatic conditions, and delocalization processes of chemical substances by metabolic activities.

The biological variations of the element content in plants were divided into 5 systematic levels, which are: 1. the plant species; 2. the population; 3. the stand (within an ecosystem); 4. the individual; and 5. the plant compartment. Each of these systematic levels can be related to: 1. genetic variabilities; 2. different climatic, edaphic and anthropogenic influences; 3. microclimatic or microedaphic conditions; 4. age of plants (stage of development), exposure to environmental influences (light, wind, pollution etc.), seasonal changes; and 5. transport and deposition of substances within the different plant compartments (organs, tissues, cells, organelles).

An expert system for random and systematic sampling for multi‐element analysis of environmental materials, such as plants, soils and precipitation is presented. After statistical division of the research area, the program provides advice for contamination‐free collection of environmental samples.  相似文献   
140.
陈炎  赵颖  熊飚 《安全与环境工程》2004,11(1):23-25,32
基于淮河流域淮河干流、沙颍河、洪河COD污染通量与河水径流量有较好相关性 ,结合汛前河流污染特点分析 ,提出了这些河流汛期污染预测经验模式。由 2 0 0 1年汛期实际污染情况对COD污染负荷与COD浓度预测结果的检验表明 ,对汛期初期阶段的预测误差在± 1 3%以内 ,根据预计降雨量对河流径流量的估计范围覆盖实际情况。  相似文献   
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