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91.
Substituted 2′-hydroxyacetophenone 4-bromophenylhydrazones are oxygenated readily in the presence of Co(Salpr) in ethanol to give 2-(4-bromophenylazo)-1,3-benzodioxoles in good yield. The results are rationalized in terms of the decomposition of a peroxy cobalt(III) complex intermediate by a mechanism similar to the Darkin oxidation. 相似文献
92.
Shuji Matsuura Pin Chen Geoffrey A. Blake J. C. Pearson Herbert M. Pickett 《International Journal of Infrared and Millimeter Waves》1998,19(6):849-858
Two-frequency operation of an 850 nm semiconductor optical amplifier was achieved by simultaneously injection seeding it with two diode lasers. The two frequencies could be independently amplified without strong interference when they were separated by more than 10 GHz, and the spectral purity was preserved by the amplification process. At frequency differences below 10 GHz, unbalanced two-frequency output was observed, which can be explained by a two-mode interaction driven by the refractive index modulation at the beat frequency. The laser system is suitable for the difference-frequency generation of coherent terahertz radiation in ultra-fast photoconductors or nonlinear optical media. 相似文献
93.
Irradiation of 5-iodouridine or 6-iodo-1,3-dimethyluracil in aq. acetonitrile in the presence of allyltrimethylsilane provided the corresponding 5- or 6-allylated product. 相似文献
94.
95.
96.
Isao Saito Shigeru Muramatsu Hiroshi Sugiyama Akihiro Yamamoto Teruo Matsuura 《Tetrahedron letters》1985,26(48):5891-5894
Photochemical hydrogen-deuterium exchange reaction of biologically important indoles is reported. The regioselectivity of the photodeuteration was found to be controlled by the ammonium group of the side chain. 相似文献
97.
Jun-ichi Watanabe Tomoyuki Sekine Kunimitsu Uchinokura Etsuyuki Matsuura 《Solid State Communications》1984,51(5):289-291
An increase in Raman intensity of surface phonon polaritons has been observed in free-standing thin slabs (thickness ~ 7 μm) of single- crystal ZnTe with rough surfaces by a conventional Raman-scattering technique at room temperature. The samples with various root-mean- square roughness heights have been prepared by making use of final polishing powders with different mean-grit sizes, and the surface roughness has been confirmed by measuring the intensities of the diffuse scattering of the laser light. The increase of the Raman intensity is proportional to the mean-square height of the surface roughness, and the shift of the dispersion relation is also proportional to it. The frequency shift is explained by a perturbation theory of the surface-roughness-induced scattering. 相似文献
98.
3-Chloro-2,5-dimethylpyrazine 1-oxide underwent cross-coupling with dialkylzinc reagents forming 3-alkyl-2,5-dimethylpyrazine 1-oxides. The reaction was realized by catalytic 1,3-bis(diphenylphosphino)-propane nickel(II) chloride and the optimum results were examined. 相似文献
99.
Among amorphous Fe2RE (RE=Er, Ce, Gd, La, Pr, Sm, Dy, Ho) alloys, Fe2Ce exhibits a tendency toward short range order, while the other Fe2RE compounds show clustering. However, we have almost no information about environments around Fe atoms. Using Mössbauer spectroscopy we have determined the quadrupole splitting distributionsP(QS) of two representative amorphous Fe2RE (RE=Ce, Er) alloys, leading to local environments of Fe atoms. The analysis of the mixed magnetic dipole and quadrupole interactions in Fe2Er shows two kinds of electrical field gradients (EFT) with the positive and negative signs in the sample, indicating a random packing of Fe atoms. Furthermore, the analyzed quadrupole splitting distributionP(QS) of Fe2Er also supports random packing in this amorphous alloy. On the other hand, the amorphous Fe2Ce alloy shows two kinds of distributions of quadrupole splitting; the major component indicating random packing and the minor component Ce-rich Ce-Fe clusters. 相似文献
100.