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81.
82.
Chemical and colloidal analyses of natural seep water collected from the exploratory studies facility inside Yucca Mountain,Nevada, USA 总被引:1,自引:0,他引:1
Cizdziel JV Guo C Steinberg SM Yu Z Johannesson KH 《Environmental geochemistry and health》2008,30(1):31-44
Yucca Mountain is being considered as a geological repository for the USA’s spent nuclear fuel and high-level nuclear waste.
Numerous groundwater seeps appeared during March 2005 within the exploratory studies facility (ESF), a tunnel excavated in
the mountain. Because of the relevance to radionuclide transport and unsaturated zone-modeling studies, we analyzed the seep
samples for major anions and cations, rare earth elements, and colloids. Major ion species and elemental concentrations in
seep samples reflect interaction of the water with the volcanic rock and secondary calcites. Elemental fractograms from flow-injection
field-flow fractionation ICP–MS scans detected Br, Ca, Cl, Cu, Fe, I, Mg, Si, Sr, W, and U at void fractions, suggesting they
may be present in the form of dissolved anions. Colloids approximately 10 nm in hydrodynamic diameter, possibly calcite, were
also present in the seepage samples. Geochemical calculations indicate, however, these may be an artifact (not present in
the groundwater) which arose because of loss of CO2 during sample collection and storage. 相似文献
83.
1999年5月—2001年10月在北京观象台对紫外线指数(UVI)进行了长期观测,结果表明:UVI季节差异明显,春、夏、秋、冬季的最大值分别为7 85,9 87,4 92,2 99;正午时的平均值分别为3 52,5 31,2 17,1 24。在UVI高峰时段(10:00—15:00),秋、冬季的UVI基本在0~2范围,对人体危害不大;而0~2,3~4,5~6,大于7的各级UVI的平均累积日照时间春季分别为159,87,47,2min,夏季分别为75,99,93,29min,春、夏季紫外线辐射对人体危害较大。另外,UVI的累积分布显示,春、秋、冬季的UVI多数集中在各季节平均值以下,而夏季正午前后的UVI多分布在其季节平均值以上。 相似文献
84.
Ferenc Csillag Sándor Kabos Tarmo K. Remmel 《Environmental and Ecological Statistics》2008,15(4):385-401
We revisit one of the classical problems in geography and cartography where multiple observations on a lattice (N) need to be grouped into many fewer regions (G), especially when this number of desired regions is unknown a priori. Since an optimization through all possible aggregations
is not feasible, a hierarchical classification scheme is proposed with an objective function sensitive to spatial pattern.
The objective function to be minimized during the assignment of observations to regions (classification) consists of two terms:
the first characterizes accuracy and the second, model complexity. For the latter, we introduce a spatial measure that characterizes
the number of homogeneous patches rather than the usual number of classes. A simulation study shows that such a classification
procedure is less sensitive to random and spatially correlated error (noise) than non-spatial classification. We also show
that for conditional autoregressive error (noise) fields the optimal partitioning is the one that has the highest within-units
generalized Moran coefficient. The classifier is implemented in ArcView to demonstrate both a socio-economic and an environmental
application to illustrate some potential applications.
相似文献
Tarmo K. Remmel (Corresponding author)Email: |
85.
The numerous formulated products which are introduced to the market consist of chemical ingredients that may cause various safety and health hazards to the consumers. Therefore, it is extremely important to practice a systematic methodology to formulate products with acceptable safety and health performances. This work presents an index-based methodology to assess the safety and health hazards of the ingredients during the early formulation stage of product design. Hence, new inherent safety and health sub-indexes are introduced to improve the current safety and health hazards that are needed in formulated product design. The inherent safety and health sub-indexes are assigned with scores based on the degree of potential hazards. A higher score indicates a higher safety risk or severe health effect, and vice versa. The proposed methodology will greatly assist the users to identify the adverse safety and health effects caused by the ingredients. Hence, it is pivotal to eliminate or reduce the safety and health impacts from product usage. A case study on common ingredients used in the formulation of paint is presented on this study to describe the proposed method. 相似文献
86.
随着可持续发展战略的实施,特别是党的十六届三中全会上科学、协调发展观的提出以及国内生态城市建设高潮的掀起,生态经济成为当前研究的热点问题之一.长江三角洲是我国经济发展与城市化水平最高的地区,被誉为世界第六大城市群,其发展状况已引起世人广泛关注.在此讨论了经济生态化的内涵,认为经济生态化水平应从经济发达程度、经济结构、生产效率、发展潜力、循环程度等几个角度来衡量,并构建了经济生态化评价指标体系;以长江三角洲地区具有代表性的八城市2004年的相关数据为操作对象,运用主成分分析法,对其经济生态化水平进行综合评价,结果表明:长三角八城市的经济生态化水平排序依次为上海、南京、苏州、无锡、宁波、杭州、常州、扬州.最后,分析了造成这种排序的原因. 相似文献
87.
88.
改进层次分析法在土壤重金属污染评价中的应用 总被引:14,自引:0,他引:14
将层次分析法进行了必要的改进 ,并应用于土壤重金属污染的评价 .评价结果表明 :改进层次分析法比模糊综合评判法以及一般层次分析法更为合理 . 相似文献
89.
通过实验证明 ,测定高锰酸盐指数时 ,空白实验的试剂空白值不完全是因蒸馏水中的还原物质消耗高锰酸钾造成的 ,提出应对《水和废水监测分析方法》(第三版 )中的有关计算公式进行修改。 相似文献
90.
有关森林公园环境容量预测的探讨 总被引:1,自引:0,他引:1
提出了预测森林公园环境容量的临界准则,进而就环境容量的预测方法、指标等结合实例进行了探讨。 相似文献