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101.
Canada, and other signatories to the London Convention 1972 on the prevention of marine pollution by dumping, are preparing to ratify a 1996 Protocol to this convention. Among the improvements to this international agreement, is a new process for the Assessment of Waste and Other Matter, which is to be adopted by signatory parties. the process includes a step in which material considered potentially acceptable for sea disposal must be characterized by chemical, physical and biological properties. Canada's interpretation and intended implementation of this characterization step is presented for the assessment of dredged sediments. This tiered testing approach involves using chemical screening limits for contaminants, and biological testing when screening levels are exceeded. Dredged material containing specified substances (e.g., cadmium, mercury, PAHs, PCBs, etc.) below or at screening levels would generally be considered of little environmental concern for disposal at sea. Wastes above the screening levels would require more detailed assessment before their suitability for disposal at sea could be determined. 相似文献
102.
Realistic meteorological fields are a prerequisite for the determination of pollutant concentrations and depositions by means
of a chemistry transport model. Different configurations of the 5th generation NCAR/Penn State University mesoscale meteorological
model MM5 were tested to determine the optimum set up for long term hindcasts that cover several months up to years. Four
dimensional data assimilation (FDDA) significantly enhances the spatio temporal representation of temperature, humidity and
wind. Best agreement with radiosonde observations could be achieved when temperature, humidity and wind were grid nudged every
6 h. The quality of the resulting meteorological fields showed no significant systematic temporal or spatial variation over
Europe in a model run of the year 2000. It was found that the hydrological cycle was not correctly reproduced by the model
when no nudging was applied. The relevant model run showed too high relative humidity and too high rainfall when compared
to observations. This led to considerably lower aerosol concentrations close to ground and a shift in the deposition patterns
of particle bound pollutants like the carcinogenic benzo(a)pyrene (B(a)P).
Guest Editor: Dr. S. T. Rao. 相似文献
103.
104.
This article attempts to examine the influence of some selected predictor variables on female age at first marriage in slum areas of Bangladesh. A path and multiple classification analysis (MCA) approach have been adopted. Authors thought that respondent's educational level and the mass media such as watching television have a significant direct impact on age at marriage, while the types of family and occupational status have an indirect effect on age at marriage. 相似文献
105.
此文主要根据冲压件“前顶梁”冲孔翻边一次成型模设计的实践经验,提出大孔径冲孔翻边一次成型的工艺分析和计算及典型结构的设计,突破了冲孔与翻边同时进行只能在Φ8以下圆孔翻边的局限,并成功地一次试模合格,为类似的圆孔翻边在Φ8以上提供了宝贵的经验。 相似文献
106.
107.
美国气象卫星监测海洋溢油 总被引:4,自引:2,他引:4
NOAA卫星主要任务是探测全球大气,通过波段筛选和各种处理,可以监测海洋原油,重柴油,润滑油溢油污染。用该卫星不仅能发现油污,确定油污位置,计算油污面积、漂移扩散方向和速度,而且可以通过连续监测寻找污染源。通过交通部已建成的全国各海监局通信网络,可以建立全国各海域油污染监测网。为改善海洋环境,加大海洋污染执法力度服务。 相似文献
108.
舟山海域突发性溢油环境风险评价 总被引:5,自引:0,他引:5
本文结合某建设项目的环境影响评价工作,开展海域突发性溢油的环境风险评价。通过风险概率计算,突发性溢油影响范围预测分析,提出舟山海域突发性溢油的应急对策。 相似文献
109.
110.
北宋大文豪苏东坡,曾先后任近十个州的地方官,为官清廉,勤政爱民,为百姓做好事。在徐州抗洪修堤、杭州治理西湖、颖州疏浚沟渠,受到百姓爱戴,堪称为古代一位水利专家。他还喜爱赏玩奇岩怪石,如砚石、仇池石、雪浪石等,也是古代一位赏石家。 相似文献