Raman scattering and photoluminescence in sodium uranyl acetate polycrystals

A technique of probe photoluminescence and Raman spectroscopy has been developed. This technique makes it possible to detect small (10^?6 to 10^?8 g) amounts of uranyl compounds at short exposure times (1?10 s). The photoluminescence spectra of Na[UO₂CH₃(COO)₃] polycrystals recorded upon excitation by short-wavelength radiation of LEDs and lasers are found to contain equidistant bands with a shift of 854 cm^?1, which corresponds to the frequency of totally symmetric uranyl vibration also manifesting itself in Raman spectra.     

Aramid Textile Laminate for Shock-Resistant Elements of Aviation Constructions

Russian Journal of Applied Chemistry - Stability against a high-speed impact of textile laminates reinforced with aramid fabrics and layered metal-textile laminates composed of alternating metallic...     

Some special inversion formulas for the laplace transform and their application to the problem of unbiased estimation of the parameters of probability distributions

Making use of the Laplace transform technique, a series of problems, regarding the unbiased estimation of the parameters of probability laws from the exponential family, are solved.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 166, pp. 17–24, 1988.     

Reactions of aldonitrones (3-imidazoline-3-oxides) with isothiocyanates

Cycloaddition of aldonitrones (derivatives of 3-imidazoline-3-oxide) to isothiocyanates depends on the N(1) substituent. Electron donating substituents facilitate cycloaddition to the C=N bond, whereas electron acceptors activate the C=S bond. Hydrolysis of adducts on the C=N bond followed by oxidation gives nitroxide radicals which are pH-sensitive spin probes.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090 Novosibirsk. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 2642–2647, November, 1991.     

Error in the determination of charged-particle density in an inhomogeneous plasma source on the basis of spectral-line broadening

The charged-particle density found from the Stark broadening of spectral lines in an inhomogeneous plasma source can be attributed with an error of 10–15% to regions of maximum spectral brightness of the line center. If the contour is recorded under conditions such that the spectral brightness of the line center is much greater than that of the wings, the experimental results can be attributed to the central regions of the inhomogeneous source. If, on the other hand, the contour is recorded under conditions such that the spectral brightness of the line center exceeds the measured spectral brightness of the wings only slightly, the experimental results should be applied to the periphery of the inhomogeneous source.Translated from Izvestiya VUZ. Fizika, No. 10, pp. 94–98, October, 1969.     

Relaxation of a liquid layer under the action of capillary forces

The theory of creeping motion is used to study the relaxation of an infinite viscous fluid layer (membrane) of nonuniform thickness. The propagation of boundary perturbations in a semi-infinite layer under the action of surface-tension forces is also considered. The layer has at least one common boundary with a gas. It is found that relaxation processes of an infinite layer or the propagation of boundary perturbations inside a bounded layer are non-monotonic, and that wave-like surface perturbations always arise. Relaxation times are determined. Maximum distances are found over which separate regions of the layer can affect each other.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, Vol. 11, No. 1, pp. 73–77, January–February, 1970.The author wishes to thank V. G. Levich for discussions.     

Large enhancement of radiative strength for soft transitions in the quasicontinuum

Radiative strength functions (RSFs) for the (56,57)Fe nuclei below the separation energy are obtained from the 57Fe(3He,alphagamma)56Fe and 57Fe(3He,3He'gamma)57Fe reactions, respectively. An enhancement of more than a factor of 10 over common theoretical models of the soft (E(gamma) less than or approximately equal 2 MeV) RSF for transitions in the quasicontinuum (several MeV above the yrast line) is observed. Two-step cascade intensities with soft primary transitions from the 56Fe(n,2gamma)57Fe reaction confirm the enhancement.     

Exact solutions of the problem of the motion of the interface between immiscible fluids in a porous medium

Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 1, pp. 68–71, January–February, 1991.