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51.
C. W. A. Evers J. J. M. Berdowski P. F. J. van der Most 《Water, air, and soil pollution》1995,85(4):1909-1914
The emission of acidifying compounds to air in the Netherlands, expressed as acidifying equivalents, consisted in 1992 mainly of NOX (45%), NH3 (35%) and SO2 (20%). Transportation, agriculture and large combustion plants each contributed about 30% to the national total emission of acidifying compounds. The emissions from transportation activities mainly consisted of NOX, while in agriculture NH3 emission strongly dominated. Combustion processes in large combustion plants resulted both in SO2 emissions (especially from refineries) and NOX emissions (especially from public power plants). The total emission of acidifying substances decreases steadily in the Netherlands. The emission in 1992 was 24% lower than in 1985. It is expected to decrease further in future. The emission levels in 1992 and 1993 still are more than twice as high as the emission objective for the year 2000, set by Dutch environmental policy. 相似文献
52.
Bland PA de Souza Filho CR Jull AJ Kelley SP Hough RM Artemieva NA Pierazzo E Coniglio J Pinotti L Evers V Kearsley AT 《Science (New York, N.Y.)》2002,296(5570):1109-1111
Impact glass associated with 11 elongate depressions in the Pampean Plain of Argentina, north of the city of Rio Cuarto, was suggested to be proximal ejecta related to a highly oblique impact event. We have identified about 400 additional elongate features in the area that indicate an aeolian, rather than an impact, origin. We have also dated fragments of glass found at the Rio Cuarto depressions; the age is similar to that of glass recovered 800 kilometers to the southeast. This material may be tektite glass from an impact event around 0.48 million years ago, representing a new tektite strewn field. 相似文献
53.
I. Lefèvre J. Ziebel C. Guignard J.‐F. Hausman R. O. Gutiérrez Rosales M. Bonierbale L. Hoffmann R. Schafleitner D. Evers 《Journal of Agronomy and Crop Science》2012,198(3):196-206
Mineral micro‐ and macronutrients in tubers of 21 Andean potato cultivars were investigated in a field trial under control and drought conditions. Mineral concentrations in potato tubers were highly variable between genotypes; some were significantly and positively correlated with each other, the most noteworthy associations being Na–Ca, Mn–Mg and Zn–Fe, in both control and drought‐stressed plants. Overall, increasing yields are related to decreased concentrations of some nutrients, albeit some higher‐yielding cultivars also displayed important concentrations of nutrients in their tubers. The most striking result was the increase in the concentration of the majority of the analysed cations in a large number of cultivars in response to water depletion; some of them, such as K, may be related to water homeostasis and/or to sucrose loading and unloading in phloem sap. Tuber mineral concentrations were not related to drought tolerance in terms of tuber productivity. Interestingly, yield loss under drought was not correlated with yield potential under control conditions. Identification of cultivars such as 703264 and 701106 able to maintain good yield stability in association with high mineral contents under water deprivation is of particular interest, especially in view of the importance of potato as a staple crop and the expansion of its cultivation to non‐optimal cultivation areas in the context of changing climatic conditions. 相似文献