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131.
Space-variant Pancharatnam-Berry phase optical elements based on computer-generated subwavelength gratings are presented. By continuously controlling the local orientation and period of the grating we can achieve any desired phase element. We present a theoretical analysis and experimentally demonstrate a Pancharatnam-Berry phase-based diffraction grating for laser radiation at a wavelength of 10.6microm. 相似文献
132.
Spiral phase elements with topological charges based on space-variant Pancharatnam-Berry phase optical elements are presented. Such elements can be achieved by use of continuous computer-generated space-variant subwavelength dielectric gratings. We present a theoretical analysis and experimentally demonstrate spiral geometrical phases for infrared radiation at a wavelength of 10.6microm . 相似文献
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135.
Marcel Baiwir Gabriel Llabrs Lon Christiaens Jean-Louis Piette 《Magnetic resonance in chemistry : MRC》1982,18(1):33-37
The 1H, 13C and 77Se chemical shifts have been measured for mononitrobenzo[ b ]selenophenes. For the homocyclic nuclei, the observed 1H- and 13C-values calculated from the empirical increments of nitrobenzene. Anomalous effects are observed in the 2- and 3-substituted derivatives and the nature of the Se? NO2 interactions in the former is discussed. 77Se chemical shifts of the 4-, 5- and 7-nitro derivatives are approximately correlated with the CNDO calculated electron densities; they also compare well with those of selenoanisoles and other phenyl alkyl selenides. The chemical shifts are also compared with the corresponding values in other heterocycles containing a selenophene moiety. 相似文献
136.
The effect of paramagnetic relaxation on perturbed angular distributions is treated for nuclei interacting with their electronic shells via isotropic hyperfine interaction. The conditions are given under which Blume's analytical stochastic-model result for the nuclear perturbation factorsG k (t) can be derived quantum mechanically. Systems with arbitrary nuclear spin, but electronic spinS=1/2 may be calculated without resorting to the assumption necessary forS>1/2. Explicit closed expressions forG k (t) can be found for this particular case. 相似文献
137.
Unzerlegbare Darstellungen I 总被引:15,自引:0,他引:15
Peter Gabriel 《manuscripta mathematica》1972,6(1):71-103
LetK be the structure got by forgetting the composition law of morphisms in a given category. A linear representation ofK is given by a map V associating with any morphism : ae ofK a linear vector space map V(): V(a)V(e). We classify thoseK having only finitely many isomorphy classes of indecomposable linear representations. This classification is related to an old paper by Yoshii [3].
Herrn Professor E. Witt zum 60. Geburtstag 相似文献
Unzerlegbare Darstellungen I
Herrn Professor E. Witt zum 60. Geburtstag 相似文献
138.
139.
Group representations without groups 总被引:2,自引:0,他引:2
140.