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The fragmentation of SO2 following dissociative electron impact excitation has been studied under single collision conditions for incident electron energies up to 500 eV. The emission spectrum in the far v.u.v. spectral range (450–1100Å) shows many features arising from excited neutral oxygen and ionized oxygen and sulphur fragments. Absolute emission cross sections have been measured for the most intense lines and the maximum values were found to range from 1–12 × 10?19 cm2 with an uncertainty of approx. ± 35%. Dissociation mechanisms are discussed and in some cases the dissociation path could be uniquely identified. The striking differences between the v.u.v. emission spectrum produced by single step dissociation of SO2 and the spectra emitted by the plasma torus around Jupiter are discussed. 相似文献
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Harry J. Schuler 《The Professional geographer》1979,31(2):146-156
Empirical testing of a decision model yields insights concerning the ways in which shoppers process information about grocery stores. Confirming hypotheses from the literature on consumer preferences, the results show that respondents are primarily concerned with quality and price of merchandise and that behavior is directly linked to derived utility measures. Clustering of the subjects discloses subtle differences among consumer groups in their approaches to evaluating the attributes of grocery stores. 相似文献
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The gravitational potential due to uniform disks and rings 总被引:1,自引:0,他引:1
The gravitational potential due to thin uniform disks and rings is obtained in closed form in terms of complete elliptic integrals. 相似文献
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K.?C.?FredrickEmail author M.?W.?Becker D.?M.?Flewelling W.?Silavisesrith E.?R.?Hart 《Environmental Geology》2004,45(8):1054-1061
Indexing methods are used for the evaluation of aquifer vulnerability and establishing guidelines for the protection of ground-water resources. The principle of the indexing method is to rank influences on groundwater to determine overall vulnerability of an aquifer to contamination. The analytic element method (AEM) of ground-water flow modeling is used to enhance indexing methods by rapidly calculating a potentiometric surface based primarily on surface-water features. This potentiometric map is combined with a digital-elevation model to produce a map of water-table depth. This is an improvement over simple water-table interpolation methods. It is physically based, properly representing surface-water features, hydraulic boundaries, and changes in hydraulic conductivity. The AEM software, SPLIT, is used to improve an aquifer vulnerability assessment for a valley-fill aquifer in western New York State. A GIS-based graphical user interface allows automated conversion of hydrography vector data into analytic elements. 相似文献