Diffraction by a corrugated interface of media: The influence of the corrugation shape and losses in the medium on total transformation regimes

We study regimes of total reflection of a plane wave to the diffraction lobe in the case where the wave is incident on a corrugated metal surface or a corrugated interface of two dielectric media. The purpose is to analyze the influence of both the corrugation shape and losses in the medium on the characteristics of the regimes of total reflection to the diffraction lobe. We consider a number of corrugation profiles differing from the sinusoid by the resonance-region width and the presence of additional elements, namely, (i) the profiles having pair resonance regions with scale of the order of the wavelength, for which qualitatively new diffraction regimes compared with those observed for the sinusoidal interface can be realized due to interaction of waves, and (ii) the profiles comprising small-scale deviations, which can be a model of actual gratings. To study the influence of losses in the problem of scattering from a corrugated interface of dielectrics, the dielectric permittivity is assumed complex. We compare the obtained results with data for a sinusoidal profile and loss-free media. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 49, No. 5, pp. 391–405, May 2006.     

Structural and thermodynamic aspects of an electron-diffraction study on saturated thallium monofluoride vapor

Ivanovo Chemical Engineering Institute. Translated from Zhurnal Strukturnoi Khimii, Vol. 30, No. 1, pp. 42–49, January–February, 1989.     

Halo Derivatives of 2,4-Dinitrothiolene 1,1-Dioxides: Synthesis and Structure

Procedures were developed for preparing representatives of a new type of halonitrothiolene 1,1-dioxides: mono- and dihalo derivatives of 2,2,4-tri- and 2,4-dinitro-3-thiolene 1,1-dioxides. An X-ray diffraction study showed that 2,5-dinitro-2,3-dichloro-3-thiolene 1,1-dioxide molecules exist in the crystal as enantiomeric pairs; the five-membered rings have the envelope conformation, with deviation of the sulfur atom from the ring plane; the halogen atom and nitro group at the multiple bond are essentially coplanar with the ring.     

Secondary ion yields produced by keV atomic and polyatomic ion impacts on a self-assembled monolayer surface

A suite of keV polyatomic or 'cluster' projectiles was used to bombard unoxidized and oxidized self-assembled monolayer surfaces. Negative secondary ion yields, collected at the limit of single ion impacts, were measured and compared for both molecular and fragment ions. In contrast to targets that are orders of magnitude thicker than the penetration range of the primary ions, secondary ion yields from polyatomic projectile impacts on self-assembled monolayers show little to no enhancement when compared with monatomic projectiles at the same velocity. This unusual trend is most likely due to the structural arrangement and bonding characteristics of the monolayer molecules with the Au(111). Copyright 1999 John Wiley & Sons, Ltd.     

Complete Radon–Kipriyanov Transform: Some Properties

Doklady Mathematics - The even Radon–Kipriyanov transform (Kγ-transform) is suitable for studying problems with the Bessel singular differential operator $${{B}_{{{{gamma }_{i}}}}} =...     

Combined STM/AFM visualization of the local density of states in the InAs/GaAs quantum dots

Combined ultra-high vacuum scanning tunneling/atomic-force microscopy (STM/AFM) has been implemented for the first time for the tunneling spectroscopy of the size-quantized states in the InAs/GaAs(001) surface quantum dots (QDs). The tunneling spectra and current images, which reflect the energy and spatial distribution of the local density of the ground and excited states in the QDs have been obtained.     

Study of resonant tunneling in Au nanoclusters on the surface of SiO2/Si thin films using the combined scanning tunneling microscopy and atomic-force microscopy technique

The morphology and electronic properties of Au nanoclusters on the surface of SiO₂ thin films on n ⁺-Si substrates are studied using the combined scanning tunneling microscopy (STM) and atomic-force microscopy (AFM) technique. The peaks associated with the resonant tunneling of electrons from the states of the valence band of the probe material to the states of the conduction band of the substrate material through Au nanoclusters are observed on the current-voltage characteristics for the contact of a p ⁺-Si AFM probe with Au nanoclusters. Experimental results are interpreted by calculating the tunnel transparency of the SiO₂/Au/SiO₂ double barrier structure in a strong electric field.     

On Ordering the Groups with Nilpotent Commutant

We prove that every group with nilpotent commutant, having an abelian normal subgroup such that the factor by this subgroup is nilpotent, is preorderable if and only if the group is -torsion-free. An example is exhibited of a nonorderable -torsion-free group with two-step nilpotent radical. This example demonstrates that for the variety of groups with nilpotent commutant the absence of -torsion in a group is not a sufficient condition for orderability.