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Electrodynamic effects/nature

The data of atomic spectroscopy are of extreme importance in revealing the nature of quantum-electrodynamical effects. For the investigation of many-electron atoms and ions, it is of great importance to combine theoretical and experimental methods. Therefore, the methods used must be universal and accurate. A number of physical characteristics of the many-electron atom (e.g., a complete set of quantum numbers) may be found only on the basis of theoretical considerations. In many cases the mathematical modelling of physical objects and processes using modern computers may successfully replace the corresponding experiments. In this book we shall describe the contemporary state of the theory of many-electron atoms and ions, the peculiarities of their structure and spectra as well as the processes of their interaction with radiation, and some applications. [Pg.446]

The first label, r, indicates the parity of the state functions, as we have just introduced in this section. The second label, r], indicates whether the Hamiltonian is time-even or time-odd. Time-even interactions are typically interactions associated with the electrostatic potential, such as the Jahn-Teller and Stark effects. Time-odd interactions are electrodynamic in nature, the most common one being the Zeeman interaction. We shall now study a function space that is invariant under time reversal... [Pg.182]

This is the nature of non-Abelian electrodynamics in a nonrelativistic regime. It leads to various predictions that appear to obtain for electromagnetic fields in media. As yet there have not been the appearance of these types of effects for fields in a vacuum. Just why it is that nonlinear optics appears to be associated... [Pg.439]

The nature of media effects relates to the fact that, since the microscopic displacement field is the net field to which molecules of the medium are exposed, it corresponds to a fundamental electric field dynamically dressed by interaction with the surroundings. The quantized radiation is in consequence described in terms of dressed photons or polaritons. A full and rigorous theory of dressed optical interactions using noncovariant molecular quantum electrodynamics is now available [25-27], and its application to energy transfer processes has been delineated in detail [10]. In the present context its deployment leads to a modification of the quantum operators for the auxiliary fields d and h, which fully account for the influence of the medium—the fundamental fields of course remain unchanged. Expressions for the local displacement electric and the auxiliary magnetic field operators [27], correct for all microscopic interactions, are then as follows... [Pg.611]

The considerable distinctions between optical spectra of a metal nanostmcture and corresponding bulk metal appear due to surface modes (plasmon-polariton resonances) in nanoparticles and size dependence of their optical constants. In the case of partially-ordered nanoparticle arrays these effects are of the collective nature because of strong electrodynamic coupling. The theoretical approach for regarding... [Pg.151]

Adsorption of enteric viruses on mineral surfaces in soil and aquatic environments is well recognized as an important mechanism controlling virus dissemination in natural systems. The adsorption of poliovirus type 1, strain LSc2ab, on oxide surfaces was studied from the standpoint of equilibrium thermodynamics. Mass-action free energies are found to agree with potentials evaluated from the DLVO-Lifshitz theory of colloid stability, the sum of electrodynamic van der Waals potentials and electrostatic double-layer interactions. The effects of pH and ionic strength as well as electrokinetic and dielectric properties of system components are developed from the model in the context of virus adsorption in extra-host systems. [Pg.97]

In Sections 3.1 and 3.2 the effect of size on IR spectra was discussed solely in the context of ultrathin Aims with plane-parallel boundaries. However, this size effect can be seen for all particles whose size is small relative to the wavelength and can lead to additional, abnormal absorption by both the particles and ultrathin Aims coating such particles. This phenomenon is well known for metals and causes metallic ultrathin films to have different colors than bulk metals. In 1857, Faraday proposed that such a color transformation is associated with the intrinsic aggregating nature of metallic films. His hypothesis has since been confirmed and understood based on Maxwell electrodynamics, and these effects have subsequently been found in the IR range for metals, dielectrics, and semiconductors. Moreover, it has been established that the particle shape also affects the IR spectrum of an ultrathin film in the closest vicinity of a system of particles that are small compared to the wavelength of irradiation. The abnormal absorption of inhomogeneous films remains the subject of intense theoretical investigations, due to the wide practical implications. However, the purpose of this section is not to review this theory in depth but rather to concentrate on the practical aspects of... [Pg.219]


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See also in sourсe #XX -- [ Pg.320 , Pg.322 ]




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Electrodynamic effects

Natural effect

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