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121.
The question whether scalar-type interactions contribute to weak interactions at large momentum transfer has been investigated by a measurement of the longitudinal polarization of positive muons produced in charged-current interactions of high-energy antineutrinos with iron. At an average momentum transfer <Q 2>=4 GeV2 the muon spin is found to be oriented forward with respect to the muon momentum vector, with an average polarization of 1.10±0.24, consistent with positive helicity. A limit on scalar contributions of σs, ptot <7% at the 95% confidence level can be deduced. A search for violation of time reversal invariance which could manifest itself by a polarization component perpendicular to the muon production plane gave a limit of σtvtot <16% (95% c.l.). It is concluded that the weak leptonic charged current retains its dominant vector and axial vector structure at large momentum transfers.  相似文献   
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Various questions of classical differential geometry lead to the problem of determining all those hypersurfaces of euclidean space for which the covariant derivative of the second fundamental form vanishes identically. In the first part of this note, we investigate these hypersurfaces; the result is summarized in the theorem of the opening paragraph, whose proof is based in the decomposition theorem of De Rham (see e.g. [6], pp. 180–186). Applying this result in the second part of the note, we give local characterizations of the Euclidean sphere.  相似文献   
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A twin GC x GC system has been designed which enables the analysis of a sample by means of two different and independent column combinations simultaneously. Both combinations are incorporated in the same oven, using the same temperature programme, and are fed using a 50:50 column-entrance-split. It is demonstrated that, employing combinations of a conventional non-polar x polar and a reversed-type polar x non-polar column set, the information content is as high, and the analytical performance is as good as when using two separate GC x GC systems. That is, there is an appreciable gain of time and a reduction of costs without any loss of quality. The general usefulness of performing, and comparing two mutually different GC x GC runs is further illustrated with FAMEs in olive oil, and pollutants in a sediment sample.  相似文献   
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A new continuously operating separating unit — a membrane rectification column — has been developed for the separation of gases by membranes. The membrane rectification column can be characterized as a “step-by-step separating process”. In this article the equations for the operating lines have been constructed to show the separating process with the new enrichment technique in the McCabe—Thiele diagram.  相似文献   
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A new effect of dynamic nuclear orientation has been observed in deuterated 1, 2-ethanediol, (CD2OH)2, at 0.12 K in a magnetic field of 25 kG: a strong RF field applied at a frequency slightly different from the proton Larmor frequency changes the deuteron tensor polarization. Mechanisms for this effect are proposed.  相似文献   
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