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New best estimates for the solid–liquid distribution coefficient (Kd) for a set of radionuclides are proposed, based on a selective data search and subsequent calculation of geometric means. The Kd best estimates are calculated for soils grouped according to the texture and organic matter content. For a limited number of radionuclides this is extended to consider soil cofactors affecting soil–radionuclide interaction, such as pH, organic matter content, and radionuclide chemical speciation. Correlations between main soil properties and radionuclide Kd are examined to complete the information derived from the best estimates with a rough prediction of Kd based on soil parameters. Although there are still gaps for many radionuclides, new data from recent studies improve the calculation of Kd best estimates for a number of radionuclides, such as selenium, antimony, and iodine.  相似文献   

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Associations between positive thyroid autoantibodies and total blood mercury in women were evaluated using the National Health and Nutrition Examination Survey (NHANES), 2007–2008. Women are at increased risk for autoimmune disorders, mercury exposure has been associated with cellular autoimmunity and mercury accumulates in the thyroid gland. We used multiple logistic regression to evaluate the associations between total bloodmercury and thyroglobulin autoantibody antibody positivity and thyroid peroxidase autoantibody positivity in non-pregnant, non-lactating women aged 20 and older not currently using birth control pills or other hormone therapies, adjusted for demographic factors, menopausal status, nutrient intake and urine iodine (n = 2047). Relative to women with the lowest mercury levels (≤ 0.40 μg/L), women with mercury > 1.81 μg/L (upper quintile) showed 2.24 (95% CI = 1.22, 4.12) greater odds for thyroglobulin autoantibody positivity (ptrend = 0.032); this relationship was not evident for thyroid peroxidase autoantibody positivity. Results suggest an association between mercury and thyroglobulin autoantibody positivity.  相似文献   

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In his keynote address, Robert Cox raised key questions, many of which force us to consider the larger question of the role of academics in society. The authors respond by suggesting that environmental communication, like other communication studies, is inherently normative and that environmental communication scholarship is closely aligned to risk as a centerpiece to crisis analysis. The authors discuss the productive connections among science, communication and sound public policy that make society more fully functional, including the formation of effective public policy through science that is normative while seeking objectivity, evaluating and symbolizing motives in discourse, acknowledging uncertainty and acceptable uncertainty, and that material and symbolic dimensions of the environment are interdependent. Thus, such studies focus on the ethics of environment and must balance sound science and cultural considerations.  相似文献   

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中国石油安全战略评价:1990-2006   总被引:1,自引:0,他引:1  
为促进国民经济的健康持续发展和国家石油安全,本文试图对中国的石油安全状况进行系统评价,为国家的石油生产和合理利用提供参考。文章从石油供给稳定和使用安全两个角度出发,构建了中国石油安全的战略评价指标体系,利用灰色关联分析方法建立了中国石油安全战略评价模型,并对1990-2006年的时间序列数据进行了实证研究。研究结果表明,中国石油安全水平呈现波动性缓慢上升的趋势。这归因于石油生产效应、石油经济效应和能源技术效应的共同作用,以及其所产生的中国石油供给稳定水平的平稳提高。同时,以GDP节能所主导的环境保护效应的波动性缓慢增强,冲击了人文效应在石油使用安全中的稳定性作用,导致了石油使用安全以及中国石油安全水平的短期波动。从经济增长、石油供给、技术进步、环境保护和人文发展的角度综合考虑中国石油安全的影响因素与发展趋势,并促进其良性作用机制的形成,是保障中国石油安全的重要途径。  相似文献   

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水-粮食贸易:虚拟水研究进展   总被引:18,自引:0,他引:18  
虚拟水思想强调的是水资源贡献,量化计算是其深入研究的基本,而是否选择虚拟水作为战略政策,应该考虑由不同国家的资源贡献和生产技术决定的比较利益。社会调适能力要求社会针对资源的第一性缺乏做相应调适并谋求解决手段,以提高资源管理能力。为此,需要结合我国的水和粮食安全问题,提出用虚拟水贸易解决我国水资源和粮食问题,提高我国对水资源缺乏的调适能力。  相似文献   

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长江中下游浅水湖泊群具有十分重要的生态服务功能。然而,该湖群正面临江湖阻隔和富营养化等严重威胁。近年来,湖泊生态环境的保护和修复越来越受到重视,但治理效果不甚明显。其根本原因是:对由流域诸多胁迫导致的湖泊问题缺乏系统全面的认识,导致头痛医头、脚痛医脚。为此,本文提出应对长江湖群实施环境-水文-生态-经济协同管理战略,即在湖泊及其流域实施环境工程以控制入湖污染,实施生态水文工程以恢复自然水文体制,实施生态修复工程以增强生物自净能力,制定水环境经济制度以建立湖泊保护修复的激励和约束机制,构建生态健康评价体系以实施适应性管理,前提是责任主体明确。  相似文献   

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Massachusetts v. Environmental Protection Agency was the first Supreme Court opinion generated specifically as a response to the issue of anthropogenic CO2 emissions, alleging that Environmental Protection Agency's (EPA) failure to regulate is leading to environmental harms for plaintiffs. This essay examines the majority opinion of Justice Stevens and his use of presumption and burden of proof, within a logic of problematic integration, to construct “certainty” as a rebuttal to and rejection of the “uncertainty” offered by EPA. I examine how this strategically constructed rebuttal to “uncertainty” functions as a declarative act of “certainty,” advancing a proposition whose scientific, legal, or political acceptance could function as a tipping point away from the claims of “uncertainty” used by opponents on this contentious issue. Because of the court's influence, the implications of their “certainty” extend beyond the case and into the broader discussion of climate change science and environmental communication.  相似文献   

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食物、能源和水资源是人类生存和发展不可或缺、不可替代的基础性资源,三者之间存在错综复杂的关联关系。城市是社会经济与资源消耗的集聚地,也是食物、能源和水资源供需矛盾冲突最为激烈的区域,食物安全、化石能源枯竭和淡水资源短缺等全球性问题已成为未来城市可持续发展面临的最大挑战。系统分析与模拟城市食物-能源-水资源的供给、需求及其关联关系,对保障城市资源供给安全、推动资源系统管理具有重要的实践意义。文章基于Stella建模平台,构建了区域关联和要素关联耦合作用下城市食物、能源与水资源供需的动态模型,以北京市为例,定量模拟了2016—2035年食物-能源-水资源系统的动态变化及其关联特征。结果表明:(1)2035年,北京城市居民粮食需求量预计约216万t,肉类83万t,总能源需求量约9 165万tce,总需水量约46亿m~3,而由本地独立生产和供给的资源量仅分别为21万t、23万t、1 650万tce和33亿m~3,本地供需缺口都呈现增大趋势,必须依赖外部地区的资源投入满足本地需求。(2)食物-能源-水资源要素之间相互作用的绝对量增加且生产"外包"特征明显,本地食物-能源-水资源关联关系向运输、处理等供应链后端环节偏移。(3)要素关联关系上,食物与水资源的耦合作用最强,能源和食物的关联程度明显增大,水资源和能源的关联程度较稳定。区域关联关系上,食物-能源-水资源系统区域间关联性增强。(4)城市资源的系统管理需要综合考虑食物-能源-水资源供需过程中的多重权衡关系,建立多区域、多要素一体化的资源协同管理机制。  相似文献   

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Place branding strategies play a significant role in the professional composition of landscape imagery, including the depiction of “natural” landscapes. In this paper, Brand Blue Mountains, a brand currently implemented in the Blue Mountains region (Australia), is discursively analyzed. The brand sets out an all-encompassing “Vision” defining the identity, values and personality of the World Heritage listed Blue Mountains landscape, summarized in the tagline Elevate Your Senses. This “vision” is visually translated into a strictly coordinated and copyrighted suite of logos, graphic design, color, fonts and various photographic styles. Analysis reveals that the degree of control that place brand strategists seek to exert over the visual expression of landscape identity is significant. A highly selective narrative of positive nature-based sensory experience is constructed through the holistic application of contemporary visual media. The brands' communications strategy naturalizes and reinforces a particular market-friendly version of place. The framework that brands set for the representation of landscapes overall amounts to an exercise in calculated aesthetics, whereby the form and content of landscape images of various kinds is measured to achieve the greatest market differentiation and impact which technologies allow. The result of this calculated aesthetic system, with its taglines, saturated color, careful composition and magazine-format brevity, is a reduction in the complexity of landscape representations and a perpetuation of nature stereotypes.  相似文献   

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Some important naturally occurring α- and β-radionuclides in drinking water samples collected in Italy were determined and the radiological quality evaluated. The mean activity concentrations (mBq L−1) of the radionuclides in the water samples were almost in the order: 26 ± 36 (234U) > 21 ± 30 (238U) > 8.9 ± 15 (226Ra) > 4.8 ± 6.3 (228Ra) > 4.0 ± 4.1 (210Pb) > 3.2 ± 3.7 (210Po) > 2.7 ± 1.2 (212Pb) > 1.4 ± 1.8 (224Ra) > 1.1 ± 1.3 (235U) > 0.26 ± 0.39 (228Th) > 0.0023 ± 0.0009 (230Th) > 0.0013 ± 0.0006 (232Th). The mean estimated dose (μSv yr−1) to an adult from the water intake was in this order: 2.8 ± 3.3 (210Po) > 2.4 ± 3.2 (228Ra) > 2.1 ± 2.1 (210Pb) > 1.8 ± 3.1 (226Ra) > 0.94 ± 1.30 (234U) > 0.70 ± 0.98 (238U) > 0.069 ± 0.087 (224Ra) > 0.036 ± 0.044 (235U) > 0.014 ± 0.021 (228Th) > 0.012 ± 0.005 (212Pb) > 0.00035 ± 0.00029 (230Th) > 0.00022 ± 0.00009 (232Th). It is obvious that 210Po, 228Ra, 210Pb and 226Ra are the most important dose contributors in the drinking water intake. As far as the seventeen brands of analysed drinking water were concerned, the committed effective doses were in the range of 2.81–38.5 μSv yr−1, all well below the reference level of the committed effective dose (100 μSv yr−1) recommended by the WHO. These data throw some light on the scale of the radiological impact on the public from some naturally occurring radionuclides in drinking water, and can also serve as a comparison for the dose contribution from artificial radionuclides released to the environment as a result of human practices. Based on the radionuclide composition in the analysed waters, comment was made on the new screening level for gross α activity in guidelines for drinking-water quality recommended by the WHO, 2004.  相似文献   

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