(NH4)4M(Zr(Hf))3F17 · 2HF Complexes (M = Li,Na): Synthesis and Physicochemical Properties

Monoclinic crystals of ammonium hydrofluoride fluoro complexes of zirconium and hafnium (NH₄)₄M(Zr(Hf))₃F₁₇ · 2HF (M = Li, Na) are synthesized and studied. Their unit cell parameters are determined. IR spectra of the synthesized compounds are measured in the range of 350–4000 cm^–1.     

Structural features of carbon materials synthesized by different methods

This paper presents the results of investigations of three types of carbon structures synthesized by different methods, such as arc discharge plasma enhanced chemical vapor deposition of carbon in a magnetic field, chemical dehydrohalogenation of the poly(vinyl chloride)/poly(vinylidene chloride) precursor, and pulsed plasma ion assisted deposition. It has been found that the samples prepared by different methods have a common feature, i.e., the presence of three-dimensional clusters based on sp²- or sp³-bonds surrounded by quasi-one-dimensional carbon chains. It has been shown that the structure of carbon materials changes depending on the synthesis conditions.     

Study of the Process $${e}^{{+}}{e}^{{-}}{\to}{\eta\pi}^{{0}}{\gamma}$$ in the Cossision-Energy Range of $$\sqrt{{s}}{=}{1.05{-}2.00}$$ GeV

Physics of Atomic Nuclei - The process $$e^{+}e^{-}\to\eta\pi^{0}\gamma$$ is studied in the range of center-of-mass (c.m.) collision energies between 1.05 and 2.00 GeV on the basis of data...     

Characteristics of solar X-ray radiation in march and April 1994 obtained in the IRIS experiment on board KORONAS-I

The first brief report on the results obtained in the IRIS experiment is presented. The IRIS instrument is an X-ray spectrometer based on proportional and scintillation counters designed for the measurement of solar X-ray radiation in the 2–200 keV range. Data on the 12 flares observed in March and April 1994 are reported, and examples of the flare radiation spectra are given.     

Specific features of localization of magnetic TM polaritons in the ferroelectric-nongyrotropic-magnet structure

The conditions are determined under which virtual slot magnetic TM polaritons are formed as a result of the quadratic magnetooptic interaction near a ferroelectric layer embedded in an easy-axis antiferromagnet.     

Effect of light with varying amplitude and frequency on a medium

A formula for the complex refractive index of a medium exposed to light whose amplitude and frequency are varied in time is derived.     

Electronically induced changes in structural properties of solid Kr

Excitation of the electron subsystem is shown to affect the structural properties of solid Kr at low temperatures. An electronically induced stable point defect formation has been observed. Experiments were performed under irradiation by electrons of subthreshold energy. Defects were detected by means of vacuum ultraviolet luminescence spectroscopy. The results obtained reveal an excited-state mechanism of defect formation when the defect is formed during the lifetime of the excited state. Self-trapping of excitons in the long-lived electronic state ³Σ⁺_u is shown to be a stimulating factor.     

Typical Changes in Spectral Properties under Perturbations by a Rank-One Operator

We show that under perturbations by a rank-one typical operator, a fixed eigenvalue loses one Jordan block of maximal order, while the orders of the other Jordan blocks remain unchanged. We construct the first-order perturbation theory for the new eigenvalues and the zero-order approximations to the corresponding eigenvectors.     

A Dirac particle in a running electric field

The wave function of the Dirac particles in the longitudinal electric field running with the velocity of light is investigated, and the condition of particle capture by this field is presented. The Dirac particles with mass m₀ and charge e that were previously stationary are captured by a repulsive field of strength E if the longitudinal field extension exceeds l = m₀c²/eE. The captured Dirac particles concentrate, like classical particles, at the distance l from the forefront of the running field, but unlike classical particles, the nth part of the Dirac particles is not captured by the field, where n = exp(−l/2λ₀) and λ₀ is the Compton wavelength of the particle. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 25–33, October, 2006.