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Vladimir P. Oleshko 《Plasmonics (Norwell, Mass.)》2008,3(1):41-46
Cryo-energy-filtering transmission electron microscopy and electron energy-loss spectroscopy have been applied to study size
confinement effects on electronic, dielectric, and optical properties of Ag(Br, I) nanocrystals. The dielectric permittivity,
optical joint density of states, refractive index, extinction, and absorption for nanocrystals derived via Kramers–Kronig
relations have been compared with experimental data for Ag(Br, I) tabular microcystals and ab initio linear muffin-tin orbital
method in its atomic spheres approximation calculations for AgBr. Contrast tuning with the selected energy window between
0 and 100 eV enabled visualizing valence electron excitations in silver halides because of plasmons superimposed with interband
transitions and Mott–Wannier excitons. The nonuniform contrast of nanocrystals revealed by cryo-energy-filtering transmission
electron microscopy was referred to a size-confined coupling of surface and volume losses that could lead to oscillations
of the image intensity with the nanocrystal size. A size-dependent enhancement of interband transitions at 4 eV correlated with the enhancement of exciton luminescence from nanocrystals because of contributions to the energy-level
structure from carrier confinement and surface states. 相似文献
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The effectiveness of the acridines ethidium bromide (EB) and acriflavine in inducing plasmon mutations was compared with the alkylating agents ethyl methanesulphonate (EMS) and diethyl sulphate and to γ-rays. The growth habit (trailing versus bunch) of peanuts (A. hypogaea), controlled by geniccytoplasmic interactions, was utilized. Breeding tests distinguishing nuclear from plasmon mutations were developed and are described in detail. Plasmon mutations were induced, but there were differences in mutation yields between the cultivars and the mutagens.In the trailing line, TBR[V4], 135 independent bunch mutations (in 1804 M2 families) were recovered: 28 bred true while 97 continued to segregate into M3 and M4. Of the 28, 14 were nuclear from an Hb to an hb allele while 14 were in the plasmon. Of the latter, 6 were induced by EMS, 7 by γ-rays and 1 by acriflavine. Somatic segregation of heteroplasmons, i.e. more plasmon mutations, could be responsible for many of the mutations that continued to segregate, but in some cases chromosomal aberrations might be involved.In the bunch cultivars there were 32 independent trailing mutations (in 3895 M2 families), one bred true for trailing, while the others continued to segregate into M3 and M4. Plasmon mutations could not be ascertained because of the continuing segregations, but these mutations manifested sorting out of heteroplasmons. 相似文献
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Joel I. Gersten 《Plasmonics (Norwell, Mass.)》2007,2(2):65-77
A theory is developed for resonant energy transfer between donor and acceptor molecules outside of a solid coated with a thin
film. The energy transfer rate is expressed in terms of a second-rank tensor, allowing one to consider all possible orientations
of the transition dipole moments of the molecules. The theory of images is employed to construct expressions valid in the
near-field approximation. This theory is extended to the full electrodynamic theory valid over all distances. Connections
are made between the expressions for the image charges and the Fresnel coefficients from optics. It is found that the energy
transfer rates are strongly influenced by surface resonances, including the interfacial surface plasmons and the two-dimensional
plasmon of a metallic film. The possibility of the film supporting Fabry–Perot resonator modes is discussed. 相似文献
4.
D. ten Bloemendal P. Ghenuche R. Quidant I. G. Cormack P. Loza-Alvarez G. Badenes 《Plasmonics (Norwell, Mass.)》2006,1(1):41-44
We report on two-photon photoluminescence (TPL) spectroscopy on metal dimers made of two gold nanoparticles separated by subwavelength distances. A direct comparison with far-field scattering measurements shows that TPL provides additional data on the structure modes of major importance for their use in surface-enhanced Raman scattering, enhanced fluorescence, and sensing. 相似文献
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