Decay rate with coordinate-dependent diffusion coefficients

Using a master equation for the reduced density matrix of open quantum system, the influence of coordinate-dependent microscopical diffusion coefficients on the decay rate from a potential well is studied. For different temperatures, frictions, heights of barrier and ratios of stiffnesses of the potential in the minimum and on the top of the barrier, the quasistationary decay rates are obtained with the sets of coordinate-dependent and -independent microscopical diffusion coefficients, and coordinate-dependent phenomenological diffusion coefficients.     

Measuring the Electric Field Strength of Microwave Radiation at the Frequency of the Radiation Transition Between Rydberg States of Atoms 85Rb

Optics and Spectroscopy - The spectral characteristics of the resonance effect of the electromagnetic-induced transparency (EIT) of rubidium atomic vapors induced by intense radiation with a...     

Nuclear structure in the dinuclear model with rotating clusters

The dinuclear-system model can be applied to nuclear structure. Here, we study deformed clusters which rotate with respect to the internuclear distance and exchange nucleons. The model can be used to explain the band structure of nuclear spectra, especially the parity splitting observed in actinides, e.g., in ²³⁸U. The text was submitted by the authors in English.     

Superdeformation as cluster state

A cluster approach is applied to describing the decay-out phenomenon of the yrast superdeformed states for mass region A≈190.     

Reaction of bicyclo[2.2.1]hept‐5‐ene‐endo‐2‐ylmethylamine and nitrophenyl glycidyl ethers

Reactions of 2‐nitro‐, 4‐nitro‐ and 2,4‐dinitrophenylglycidyl ethers with bicyclo[2.2.1]hept‐5‐ene‐endo‐2‐ylmethylamine in isopropanol have been studied. The mixtures of products were chromatographed on silica gel and eluted with ether or ether/2‐propanol (1:1), the structures of individual products have been confirmed by IR spectra, NMR ¹H, ¹³C spectra, using experiments that involve homonuclear and heteronuclear scalar coupling interactions (COSY, TOCSY, HMQC, HMBC), and mass spectrometry. Amino alcohols as the major products of regioselective aminolysis of epoxides (according to the Krasusky rule) have been obtained. The minor products were the compounds with two hydroxyalkyl fragments at the nitrogen atom. In case of dinitrophenylglycidyl ether, it was the minor product of aryl nucleophilic substitution (S_NAr). The abnormal course of aminolysis has been confirmed by the results of quantum‐chemical calculations of activation barries and Free Gibbs energies of the competitive reactions of epoxides (at the B3LYP/6‐311 + G(d,p) level of theory). Copyright © 2010 John Wiley & Sons, Ltd.     

Selective laser pumping of magnetic sublevels in the hyperfine structure of the cesium atom

The evolution of the populations of the magnetic sublevels of the cesium atom (¹³³Cs isotope) in resonant laser fields with linear polarization is analyzed using the equations for the density matrix. Analytic expressions are derived for stationary populations resulting from laser-induced optical transitions on the hyperfine structure components F _g = 3 ? F _e = 2, 3 and F _f = 4 ? F _e = 3, 4 of lines D ₁ (6² S _1/2 → 6² P _1/2) and D ₂ (6² S _1/2 → 6² P _3/2) depending on the initial values of the populations. The numerical solution of the evolution equations gives the characteristic times of stabilization of the steady regime as functions of laser field intensities and detuning from optical resonance. We determine the sequences of optical transitions increasing (by more than an order of magnitude) the population of the lower sublevel 6² S _1/2 F _g = 3 M = 0 of the “clock” microwave transition F _g = 3 M = 0 ? F _f = 4 M = 0 in the cesium frequency standard, which increases the signal intensity in the recording system by the same proportion.     

New X-Ray Techniques for Flow Visualization and Measurement of Hydrodynamic Flow Parameters in Opaque Heterogeneous Media

This paper proposes and validates a method for the quantitative analysis of multiphase flows and objects of complex composition with image registration on a charge-coupled-device array taking into account the X-ray spectral characteristics. The method was tested on objects of known composition and shape. New approaches are formulated to solve a number of research problems related to the use of modern registration techniques and computer-based tools for X-ray image processing. __________ Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 46, No. 6, pp. 159–170, November–December, 2005.     

Spectrozonal digital X-ray diagnostics of explosive processes, based on imageplate detectors separated by an absorber

A method that uses overlapping calibration wedges, made from the materials being investigated and placed alongside an object, is proposed for calculating the individual thicknesses of two-component objects. On detectors separated by an absorber, images in two different ranges of X-ray hardness are recorded with a single flash. As a result, there is no need to know the spectrum of X-ray radiation source or the spectral characteristics of the radiographed objects or the detector in order to solve the inverse problem.     

Analysis of the Tesla transformer operation at the first half-wave of the output voltage taking into account ohmic losses

The speed and efficiency of the Tesla transformer at the first half-wave of the output voltage are studied as a function of the Q factors of the circuits and their coupling factor. Calculated results and experimental data are considered. It is shown that for given Q factors, there is an optimal value of the coupling factor providing the highest efficiency, which can be calculated and for which designers should work.