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71.
R. Khare P.K. Shukla G.K. Mishra C. Mukherjee S. Talwar V.K. Dubey P. Saxena J.K. Mittal 《Optics Communications》2009,282(19):3850-3853
We present an analytical and experimental study of a novel confocal optical pulse stretcher (COPS). The simple and passive pulse stretcher consists of two concave mirrors and a scraper beam-splitter and its optical configuration ensures a perfect spatial overlapping of laser pulses at the beam-splitter. The pulse stretcher is compact and suitable for laser pulses of large divergences. The confocal optical pulse stretcher is demonstrated on a pulsed copper vapour laser to convert a 40 ns (1/e2 % points) pulse into a 55 ns with reduction of peak power by a factor of 1.375 without loss of pulse energy. 相似文献
72.
N-Cinnamoyl-L-proline can be used as a template on which beta-substituted phenylalanine and beta-phenylisoserine residues can be synthesized leading to tripeptide derivatives as structural analogues of HIV protease inhibitors. 相似文献
73.
d'Astuto M Mang PK Giura P Shukla A Ghigna P Mirone A Braden M Greven M Krisch M Sette F 《Physical review letters》2002,88(16):167002
The phonon dispersions of Nd(1.86)Ce(0.14)CuO(4+delta) along the [xi,0,0] direction have been determined by inelastic x-ray scattering. Compared to the undoped parent compound, the two highest longitudinal phonon branches, associated with the Cu-O bond stretching and out-of-plane oxygen vibration, are shifted to lower energies. Moreover, an anomalous softening of the bond-stretching band is observed at about q = (0.2,0,0). These signatures provide evidence for strong electron-phonon coupling in this electron-doped high-temperature superconductor. 相似文献
74.
Dallera C Grioni M Shukla A Vankó G Sarrao JL Rueff JP Cox DL 《Physical review letters》2002,88(19):196403
Resonant inelastic x-ray scattering (RIXS) yields clear evidence of spectroscopic Kondo scales in heavy fermions. In YbInCu4 and YbAgCu4 RIXS probes the Yb2+ component of the hybrid ground state and the temperature dependence of the Yb 4f occupation. We report a sudden valence change at a phase transition in YbInCu4, but a continuous temperature dependence in YbAgCu4, consistent with the predictions of the Anderson impurity model, for a Kondo temperature T(K) = 70 K. These results solve a long-standing controversy and establish RIXS as a quantitative probe of the electronic structure of strongly correlated electron systems. 相似文献
75.
The present paper considers the magnifying power and aberration properties of three different catadioptric magnifying systems
useful for application as simple hand-held microfiche readers. These are in the form of a plano-convex lens, a meniscus lens
and an achromatic doublet lens and all their outer surfaces have been coated with a semi-reflecting film so that they behave
like catadioptric elements. These can be designed to give magnification in the range of 15 × to 25 × with sufficient eye relief.
Using such magnifiers, it is possible to read microfiche having frame sizes of 16 × 12 mm and 12 × 9 mm. The cemented achromatic
doublet coated on the outer surfaces seems to give a very good image for use in microfiche reader. 相似文献
76.
Rivail and Rinaldi's scheme to work out the quantum static multipole polarizabilities have been extended to recover convergence in it. Our expressions give exact static multipole polarizabilities for the atomic hydrogen and give reasonable values for He-sequence. 相似文献
77.
Purely ponderomotive force-driven electron motion is shown to produce spiky electron whistler solitary waves. 相似文献
78.
79.
80.
A micro method has been developed for the determination of oxprenolol hydrochloride and metoprolol tartrate in pure form and in pharmaceutical preparations, with vanadium(V) in acidic medium. 相似文献