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961.
社会的安全保护与可持续发展 总被引:2,自引:0,他引:2
事故、灾害、环境、社会是一个互馈的系统 ,安全科学研究的对象不仅仅是技术安全问题 ,应从狭义的范畴转向广义的范畴。本文分析了事故树与自然灾害系统的结构 ,认为社会安全保护与可持续发展密不可分 ,并提出了建立社会安全保护体系的对策。 相似文献
962.
963.
Eric Michnowsky Leslie M. Churchland Patricia A. Thomson Paul H. Whitfield 《Journal of the American Water Resources Association》1982,18(1):129-132
ABSTRACT: Changes in metal concentrations during storage of acidified water samples were studied. Water samples with high concentrations of suspended sediment were collected from the Fraser River, British Columbia. These samples were analyzed for “extractable” metals, which are defined to be the dissolved metals plus those metals extracted from suspended sediment by dilute mineral acid. Concentrations of extractable Cu, Fe, Pb, Zn, Ni, Co, Mn, and Cd were determined over time. Metal concentrations in these water samples were not stable and showed significant increases throughout the storage period. These results suggest that the extractable metal technique is inappropriate for the analysis of water samples containing suspended sediment. 相似文献
964.
The Peruvian altiplano is a marginal agricultural region with limited infrastructure, climate constraints, and high levels of poverty. Data were collected from 265 farms in four different agricultural regions, and data from three of those regions are analyzed here. Regressions were run with soil nutrient loss, soil depth loss, and yield loss over the past 20 years, as perceived by farmers. Location, topographical and management factors were considered. Additional regressions were run to examine the determinants of two agricultural management practices which were found to affect soil quality, namely fallowing and ploughing vertical furrows. Use of traditional fallowing (aynoca) was associated with helping to preserve soil quality, and was practiced by households with more education, with higher non-farm income, and in villages which had benefitted from natural resource development projects. Vertical furrowing similarly was associated with helping preserve soil quality, and was practiced by households with fewer unmet basic needs. These results have implications for the agricultural and development strategies to be followed in the region. 相似文献
965.
V. A. Yakovlev 《Russian Journal of Ecology》2002,33(4):268-272
Classification of the mode of life and behavior of zoobenthic, nektobenthic, and neustonic organisms was used as a basis for elucidating the formation of ethological structure of their communities in small lakes and streams of northeastern Fennoscandia. It is shown that the general response of these communities to anthropogenic impact is manifested in the reduction of the number of ethological groups. The specific response to eutrophication and heat pollution involves a decrease in the relative biomass of clingers and burrowers and an increase in the biomass of sprawling–walking and wormy animals; the response to toxic pollution and acidification is manifested in the prevalence of sprawlers–walkers. 相似文献
966.
Serena Risica 《Chemistry and Ecology》1996,12(4):225-230
Following a similar project performed for the Northern European Seas in the years 1985-1990, a study on the radioactive contamination of the Mediterranean Sea has recently been conducted by a group of experts of the European Union (MARINA-MED Project). Its aim was to assess the radiological exposure of the population of the European Union, due both to natural and man-made radionuclides in the Mediterranean Sea. A review of the conclusions of this study is presented, with special attention to the environmental radioactive data. the Italian radioactive monitoring organisation is described. Starting from this experience, some proposals for new research projects are presented. 相似文献
967.
Christopher A. Ellison Quentin D. Skinner Katta J. Ready 《Journal of the American Water Resources Association》2006,42(1):55-68
Sage Creek in south‐central Wyoming is listed as impaired by the U.S. Environmental Protection Agency (USEPA) due to its sediment contribution to the North Platte River. Despite the magnitude of sediment impacts on streams, little research has been conducted to characterize patterns of sediment transport or to model suspended sediment concentration in many arid western U.S. streams. This study examined the relationship between stream discharge and suspended sediment concentration near the Sage Creek and North Platte River confluence from 1998 through 2003. The objectives were to determine patterns of stream discharge and suspended sediment concentration, produce a sediment prediction model, and compare sediment concentrations for the six‐year period. Stream discharge and suspended sediment transport responded rapidly to convective storms and spring runoff events. During the study period, events exceeding 0.23 m3/s accounted for 92 percent of the sediment load, which is believed to originate from erodible headwater uplands. Further analysis of these data indicates that time series modeling is superior to simple linear regression in predicting sediment concentration. Significant increases in suspended sediment concentration occurred in all years except 2003. This analysis suggests that a six‐year monitoring record was insufficient to factor out impacts from climate, geology, and historical sediment storage. 相似文献
968.
蓄滞洪区可持续发展评价指标体系及案例研究 总被引:3,自引:0,他引:3
本文以蓄滞洪区复合系统为评价对象,在对相关子系统进行综合分析的基础上,设计了可持续发展评价指标体系,并以洪湖蓄滞洪区为实例,对其发展资本、发展水平、防洪情势和综合发展度进行了评价,分析了洪湖蓄滞洪区各个子系统之间的协调关系。评价结果表明:洪湖蓄滞洪区的发展资本和发展水平都处于比较良好的状态,防洪情势为风险型,是洪湖蓄滞洪区可持续发展的制约因素。洪湖蓄滞洪区实现可持续发展的重点是解决社会经济与防洪子系统之间的矛盾,加强防洪子系统的发展,改善社会经济结构,同时注意保护和利用环境。 相似文献
969.
根据几十年来武汉东湖水质监测资料和数据 ,在东湖截污工程完成后 ,没有新的污染物进入水体的前提下 ,对东湖水体通过自然净化恢复到健康状态所需要的时间进行了详细的数学推导和科学论证。结果表明 ,在不考虑地泥营养物质的情况下 ,东湖水体通过工业、农业、生活用水以及收获鱼类和高等植物造成的营养物的输出 ,只需要 3a左右的时间就能恢复。然而如果考虑地泥的影响 ,几十年沉积在地泥的营养物质持续向水体中释放 ,然后再通过用水及生物输出 ,东湖水质需要35a以上才能得到恢复。可见 ,截污后东湖在相当长的时间内还将处于富营养化状态 ,地泥是造成东湖长期富营养化的关键。解决东湖污染问题的关键是清除地泥 ,因此得出结论 :挖底泥后引入长江水源来加速东湖水体改善的最佳途径 相似文献
970.
Sialic acid storage disorders, Salla disease (SD) and a severe infantile form of disease (ISSD), are recessively inherited allelic lysosomal storage disorders due to impaired egress of free sialic acid from lysosomes. Fourteen pregnancies at risk of adult-type free sialic acid storage disease, SD, were monitored by sialic acid assays, genetic linkage or mutation detection analyses using chorionic villus samples. Three affected and 12 unaffected fetuses were identified. The first studies were based on the sialic acid assays alone, but the location of the gene enabled the use of genetic linkage analysis and, more recently, the identification of the SLC17A5 gene and disease-causing mutations added yet another possibility for prenatal studies. A missense mutation 115C→T (R39C) is present in 95% of all Finnish SD alleles, providing an easy and reliable means of diagnostic studies. Both molecular and biochemical (sialic acid assay) studies can be used for prenatal diagnosis of free sialic acid storage diseases. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献