133 resultados para 7140-239


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We investigate the group valued functor G(D) = D*/F*D' where D is a division algebra with center F and D' the commutator subgroup of D*. We show that G has the most important functorial properties of the reduced Whitehead group SK1. We then establish a fundamental connection between this group, its residue version, and relative value group when D is a Henselian division algebra. The structure of G(D) turns out to carry significant information about the arithmetic of D. Along these lines, we employ G(D) to compute the group SK1(D). As an application, we obtain theorems of reduced K-theory which require heavy machinery, as simple examples of our method.

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Theoretical electron density sensitive emission line ratios involving a total of eleven 2s(2)2p(2)-2s2p(3) transitions in S XI between 187 and 292 Angstrom are presented. A comparison of these with solar active region observations obtained during rocket flights by the Solar EUV Rocket Telescope and Spectrograph (SERTS) reveals generally good agreement between theory and experiment. However, the 186.87 Angstrom line is masked by fairly strong Fe XII emission at the same wavelength, while 239.83 Angstrom is blended with an unknown feature, and 285.58 Angstrom is blended with possibly N IV 285.56 Angstrom. In addition, the 191.23 Angstrom line appears to be more seriously blended with an Fe XIII feature than previously believed. The presence of several new S XI lines is confirmed in the SERTS spectra, at wavelengths of 188.66, 247.14 and 291.59 Angstrom, in excellent agreement with laboratory measurements. In particular, the detection of the 2s(2)2p(2) P- 3(1) -2s2p(3) P-3(0,1) transitions at 242.91 Angstrom is the first time (to our knowledge) that this feature has been identified in the solar spectrum. The potential usefulness of the S XI line ratios as electron density diagnostics for the solar transition region and corona is briefly discussed.