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591.
A near-infrared Raman system was developed to collect real-time in vivo human lung spectra. The excitation light and the emission were guided to and from the tissue surface by a reusable fiber catheter passed down the instrument channel of a bronchoscope. Two-stage filtering was used to reduce laser noise, fluorescence, and Raman emissions from the fibers. A second fiber bundle guided the emission to a spectrometer where the fibers, in a round packing geometry, were spread out to form a parabolic arc that improved the signal-to-noise ratio 20-fold, facilitating real-time spectral measurements. Preliminary clinical tests show that clear and reliable Raman spectra can be obtained. 相似文献
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For finitep-groupsG we study the conjugation representation γG which is defined by lettingG act on itself by conjugation. Roth conjectured that every irreducible representation ofG which is trivial on the center ofG, occurs in γG. However, this is not true in general. We construct minimal counterexamples and verify Roth's conjecture for various classes
of finitep-groups, for instance those of maximal class.
Dedicated to Professor George Maltese on the occasion of his 60th birthday 相似文献
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We present the life and work of the Norwegian scientist Ellen Gleditsch (1879-1968) in the early
era of radioactivity. From 1907-1912, Gleditsch worked as Marie Curies assistant in the Laboratoire
Curie in Paris on the alleged copper-lithium radioactive transformation and on the radiumuranium
ratio, as well as studying chemistry and related subjects at the Sorbonne. Later,in 1913-1914,
she worked in Bertram Boltwoods laboratory at Yale University on the half-life of radium. Gleditsch
also was concerned with academic opportunities for women, and she became the president
of the International Federation of University Women. As a professor, the second female professor
in Norway, she initiated a research group on radioactivity at the University of Oslo. 相似文献
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Källström K Hedberg C Brandt P Bayer A Andersson PG 《Journal of the American Chemical Society》2004,126(44):14308-14309
A new class of chiral N,P-ligands for the Ir-catalyzed asymmetric hydrogenation of aryl alkenes has been developed. These new ligands proved to be highly efficient and tolerates a broad range of substrates. The enantiomeric excesses are in the range of the best ever reported. The results can be rationalized with the proposed selectivity model. 相似文献