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大学英语四六级晨读经典365:秋日激情篇 194 Lead Deposits铅沉淀(mp3)

merryangle87 于2014-10-13发布 l 已有人浏览
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20世纪六七十年代铅积聚在泥土与雪中所造成的铅沉积现象,它主要是由于在美国含铅汽油燃烧后尾气排放所导致的结果。
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194 Lead Deposits

194 铅沉淀

Lead deposits, which accumulated in soil and snow during the 1960's and 70's, were primarily the result of leaded gasoline emissions originating in the United States. In the twenty years that the Clean Air Act has mandated unleaded gas use in the United States, the lead accumulation world-wide has decreased significantly.

20世纪六七十年代铅积聚在泥土与雪中所造成的铅沉积现象,它主要是由于在美国含铅汽油燃烧后尾气排放所导致的结果。在过去的20年里《空气洁净法案》要求在美国只能使用无铅汽油,因此世界范围内的铅沉积有了显著下降。

A study published recently in the journal Nature shows that air-borne leaded gas emissions from the United States were the leading contributor to the high concentration of lead in the snow in Greenland. The new study is a result of the continued research led by Dr. Charles Boutron, an expert on the impact of heavy metals on the environment at the National Center for Scientific Research in France. A study by Dr. Boutron published in 1991 showed that lead levels in arctic snow were declining.

一篇发表在《自然》上的文章表明,来自于美国的被排放到空气中的含铅气体是格林兰雪中铅高度聚集的主要原因。这一新发现是查尔斯·伯顿博士长时间苦心钻研的成果,他是法国国家自然科学研究中心研究重金属对环境影响的专家。1991年,伯顿博士发表的一篇研究文章指出北极看中的含铅水平正在下降。

In his new study, Dr. Boutron found the ratios of the different forms of lead in the leaded gasoline used in the United States were different from the ratios of European, Asian and Canadian gasolines and thus enabled scientists to differentiate the lead sources. The dominant lead ratio found in Greenland snow matched that found in gasoline from the United States.

在伯顿博士的新研究中,他发现美国使用的不同形式街铅汽油中铅的比重与欧洲,亚洲和加套太的汽油中的含铅量不同,这使得科学家们能够区分铅的来源。含量最大的铅与在美国的含铅汽油的铅比重相吻合。

In a study published in the journal Ambio, scientists found that lead levels in soil in the North-eastern United States had decreased markedly since the introduction of unleaded gasoline.

在一篇发表在《人类环境杂志》上的研究文章中,科学家发现自从引入无铅汽油后,美国东北部土壤中的含铅水平已经有了显著的下降。

Many scientists had believed that the lead would stay in soil and snow for a longer period.

许多科学家认为铅会在土壤和雪中的存留很长的时间。

The authors of the Ambio study examined samples of the upper layers of soil taken from the same sites of 30 forest floors in New England, New York and Pennsylvania in 1980 and in 1990. The forest environment processed and redistributed the lead faster than the scientists had expected.

《人类环境杂志》上的研究文章的作者在1980年和1990年分别检测了取自新英格兰。纽约和宾夕法尼亚20个森林土地统一地方的表层土壤样本。森林环境调节和重新分配铅的速度比科学家们预期的要快。

Scientists say both studies demonstrate that certain parts of the ecosystem respond rapidly to reductions in atmospheric pollution, but that these findings should not be used as a license to pollute.

科学家们说两个研究都证实了生态系统的某些部分对大气污染降低反应迅速,不过这些研究结果当然不应成为随意污染环境的许可证。

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