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691.
Coppedge BR Engle DM Masters RE Gregory MS 《Environmental monitoring and assessment》2006,118(1-3):125-145
We utilized landscape and breeding bird assemblage data from three Breeding Bird Survey (BBS) routes sampled from 1965–1995
to develop and test a grassland integrity index (GII) in a mixed-grass prairie area of Oklahoma. The overall study region
is extensively fragmented from long-term agricultural activity, and native habitat remnants have been degraded by recent encroachment
of woody vegetation, namely eastern redcedar (Juniperus virginiana L.). The 50 individual bird survey points along the BBS routes, known as stops, were used as sample sites. Our process first
focused on developing a grassland disturbance index (GDI) as a measure of cumulative landscape disturbances for these sites.
The GDI was based on five key landscape variables identified in an earlier species-level study of long-term avian community
dynamics: total tree, shrub, and herbaceous vegetation cover indices, overall mean landscape patch size, and grassland patch
core size. The GII was then developed based on breeding bird assemblage data. Assemblages were based on commonly used response
guilds reflective of five avian life history parameters: foraging mode/location, nesting location, habitat specificity, migratory
pattern, and dietary guild. We tested the response of 78 candidate assemblage metrics to the GDI, and eliminated those with
no or poor response or with high correlations (redundant), resulting in 13 metrics for use in the final index. Individual
metric scores were scaled to fall between 0 and 10, and the cumulative index to range from 0 to 100. Although broader application
and refinement are possible, the avian-based GII has an advantage over labor-intensive, habitat-based monitoring in that the
GII is derived from readily available long-term BBS data. Therefore, the GII shows promise as an inexpensive tool that could
easily be applied over other areas to monitor changes in regional grassland conditions. 相似文献
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中国有害废物污染现状与控制对策探讨 总被引:12,自引:0,他引:12
我国有害废物对土壤,水体,大气及生物污染相当严重,在一些地区已构成了对人体健康的影响和威胁,已成为当前亟待解决的一个重大环境问题。本文介绍我国有害废物的污染现状,并通过对国内外有废物污染控制技术和管理水平的综合分析与对照,结合国情提出了我国有害废物污染对策和建议。 相似文献
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在全面推进乡村振兴背景下,探索碳汇产品价值实现是对习近平生态文明思想的践行,也是实现生态保护补偿和绿色发展的重要市场化手段。进入数字时代,基于区块链技术的智能合约,因技术优势带来的发展优势,其与各行业不断融合,并形成新的发展思路和发展业态。探索将智能合约技术嵌入碳汇产品交易,可以降低碳汇产品交易成本,提高碳汇产品交易效率。然而,新兴技术的应用是一把双刃剑,智能合约能够为碳汇产品价值实现带来诸多优势,但同时也将引发实体法、程序法以及新业态监管方面的挑战。因此,为实现智能合约在碳汇产品价值实现领域的全面可持续应用,应当从实体法、程序法以及新业态监管机制等方面,探索法律应对路径的理性回归。 相似文献
697.
On the basis of the literature of open systems and team diversity, we present a new dynamic team diversity theory that explains the effect of change in team diversity on team functioning and performance in the context of dynamic team composition. Building upon the conceptualization of teams as open systems, we describe the enlargement and decline of team variety, separation, and disparity through member addition, subtraction, and substitution. Then, focusing on diversity enlargement, we theorize the contemporaneous and lasting effects of team diversity change on team performance change and on team processes and states leading to them. Dynamic team diversity theory expands the focus of team diversity research from teams' being more diverse than others to teams' becoming more diverse than before. It aims to advance team diversity research to be better aligned with the organizational reality of dynamic team composition. We also discuss methodological considerations in subsequent empirical testing of the theory and highlight how the theory and future research may help to guide organizational practice in recomposing work teams. 相似文献
698.
The intensity of environmental regulation (ERI) affects the short-term effect of the level of green mining (GML), and which structure determines the long-term mechanism. Based on the panel data from 2001 to 2015, with the dynamic panel model and system GMM estimation method were employed to test the influence of heterogeneous environmental regulation on green mining and its transmission mechanism. The results show that, there is a “U” type nonlinear relationship between the ERI and GML. The direct effect of command-control-based (CAC) and the market incentive-based (MBI) environmental regulation on green development of mining shows the characteristics of inhibition and promotion. There is a “U” type of indirectly moderating effect between technological innovation and the energy consumption structure on the GML. The technological innovation promotes the green development of the mining industry only after pass the inflection point of MBI, while the CAC plays a significant guiding role in upgrading of the energy consumption structure. There is an inhibition and promotion effect of MBI on the GML in the southeast coastal area, and the CAC is not significantly. Meanwhile, both of the ERI shows no positive effects in the central and western inland region. 相似文献
699.
Jing Feng HeeSun Choi Fergus I. M. Craik Brian Levine Sylvain Moreno Gary Naglie 《Traffic injury prevention》2018,19(2):141-146
Objectives: The majority of existing investigations on attention, aging, and driving have focused on the negative impacts of age-related declines in attention on hazard detection and driver performance. However, driving skills and behavioral compensation may accommodate for the negative effects that age-related attentional decline places on driving performance. In this study, we examined an important question that had been largely neglected in the literature linking attention, aging, and driving: can top-down factors such as behavioral compensation, specifically adaptive response criteria, accommodate the negative impacts from age-related attention declines on hazard detection during driving?Methods: In the experiment, we used the Drive Aware Task, a task combining the driving context with well-controlled laboratory procedures measuring attention. We compared younger (n = 16, age 21–30) and older (n = 21, age 65–79) drivers on their attentional processing of hazards in driving scenes, indexed by percentage of correct responses and reaction time of hazard detection, as well as sensitivity and response criteria using signal detection analysis.Results: Older drivers, in general, were less accurate and slower on the task than younger drivers. However, results from this experiment revealed that older, but not younger, drivers adapted their response criteria when the traffic condition changed in the driving scenes. When there was more traffic in the driving scene, older drivers became more liberal in their responses, meaning that they were more likely to report that a driving hazard was detected.Conclusions: Older drivers adopt compensatory strategies for hazard detection during driving. Our findings showed that, in the driving context, even at an older age our attentional functions are still adaptive according to environmental conditions. This leads to considerations on potential training methods to promote adaptive strategies that may help older drivers maintain performance in road hazard detection. 相似文献
700.
针对突发事件下多种信息共存情境中信息交互传播的调控问题,首先界定了该情境中“涌现→传播”过程的组成要素,建立了信息交互关系框架及其系统动力学模型;其次,通过设计和仿真基础情景,将仿真结果与案例进行对比,检验模型的模拟趋势与现实状况的一致性;最后,通过设计和仿真实验情景,考查决策者的关键可控因素对系统演化的影响。研究结果表明:官方渠道所发布信息的可信度、平均个体传播量及群体的立场认知水平,与相信和传播官方渠道信息的人数均正相关,而与相信和传播民间渠道信息的人数均负相关;对各群体数量演化影响的显著性而言,官方渠道信息的平均个体传播量最高,官方渠道信息的可信度次之,群体的立场认知水平较低。 相似文献