Multicomponent photorefractive cnoidal waves: stability, localization, and soliton asymptotics

An algorithm of building up a different class of stable self-consistent multicomponent periodical solutions of the nonlinear Schr?dinger equation--multicomponent cnoidal waves--has been formulated by the example of a nonlinear wave propagating through a photorefractive crystal with a drift nonlinear response. Exact analytical expressions, describing distribution of light field in the components, have been obtained for solutions, which include up to three mutually incoherent components. It has been shown that such cnoidal waves are stable and their spatial structure is robust to collisions with the same cnoidal waves and to stochastic perturbations of the components' intensity distributions in a sufficiently wide range of changing spatial period.     

Rate constants of the reaction between alkyl radicals and oxygen and stable nitroxyl radicals

Conclusions The rate constants of the reaction between the alkyl radicals of hydrocarbons (R^.) and of vinyl monomers (M^.) and O₂ and stable nitroxyl radicals were determined at 50C. The low-molecular-weight radicals react with O₂ (k₁) and the (k₃) more rapidly than the M^. do. For polar R^. and M^. k₁ and k₃ are close, and for the nonpolar ones k₁>k₃.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2446–2450, November, 1979.The authors express their appreciation to V. A. Golubev for submitting the nitroxyl radicals and A. P. Moravskii for help in running the experiment.     

Effect of surface potential and intrinsic magnetic field on resistance of a body in a supersonic flow of rarefied partially ionized gas

The character of flow over a body, structure of the perturbed zone, and flow resistance in a supersonic flow of rarefied partially ionized gas are determined by the intrinsic magnetic field and surface potential of the body. The effects of intrinsic magnetic field and surface potential were studied in [1–4]. There have been practically no experimental studies of the effect of intrinsic magnetic field on flow of a rarefied plasma. Studies of the effect of surface potential have been limited to the case R/_d<50 [1, 3]; this is due to the difficulty of realization of flowover regimes at R/_d>10² (where R is the characteristic dimension of the body and X is the Debye radius). At the same time R/_d>10², the regime of flow over a large body, is of the greatest practical interest. The present study will consider the effect of potential and intrinsic magnetic field on resistance of a large (R/_d>10²) axisymmetric body (disk, sphere) in a supersonic flow of rarefied partially ionized gas.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 3, pp. 41–47, May–June, 1986.     

Charge transfer by high-energy electrons onto the leeward surfaces of a solid in a supersonic rarefied plasma flow

Numerical and experimental dependence of equilibrium potentials of the leeward surfaces on the ratio of concentrations of high-energy electrons and positive ions in a supersonic rarefied plasma flow around a solid are obtained. __________ Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 1, pp. 13–23, January–February, 2008.     

A monoclinic polymorph of uranyl dinitrate trihydrate, [UO2(NO3)2(H2O)2]·H2O

Di­aqua­dinitratouranyl(VI) monohydrate is monoclinic (space group P2₁/c), in contrast to its triclinic polymorph. The main building block of the structure is the finite non‐centrosymmetric [UO₂(NO₃)₂(H₂O)₂] cluster, which is a uranyl hexag­onal bipyramid that shares two non‐opposite equatorial edges with the nitrate triangles, such that the two water mol­ecules are at neighbouring equatorial vertices. There is an interstitial water site in the structure, which is located between adjacent [UO₂(NO₃)₂(H₂O)₂] clusters.     

Nuclear Magnetic Resonance and Infrared Spectroscopy Examination of Blood for Diagnosis of the Diffuse Hepatopathy State

Optics and Spectroscopy - 67 middle-aged (48 ± 1 years) patients with diffuse liver disease of various origins have been examined. It has been established that an increase in the degree of...     

Tomographic Estimation of Waterbody Parameters in the Presence of Ice Cover Using Seismoacoustic Sources

Acoustical Physics - The article presents the results of field tests of marine seismic sources and seismoacoustic areal measuring systems based on autonomous embedded buoys in Lake Ladoga under ice...     

New Possibilities of the Kabachnik–Fields and Pudovik Reactions in the Phthalocyanine-Catalyzed Syntheses of α-Aminophosphonic and α-Aminophosphinic Acid Derivatives

The results of systematic studies demonstrated wide possibilities of the three-component Kabachnik–Fields and two-component Pudovik reactions catalyzed by metal phthalocyanines in the synthesis of structurally diverse α-aminophosphonates. Extension of this catalytic method to the synthesis α-aminophosphinates gave rise to a series of α-amino- and α-hydrazinophosphinates based on biogenic amino acids. A number of α-hydrazinophosphonates showed a good antioxidant activity.     

Astolides A and B,antifungal and cytotoxic naphthoquinone-derived polyol macrolactones from Streptomyces hygroscopicus

Two new natural compounds, astolides A,B, were isolated from Streptomyces hygroscopicus collected from the alkaline soil obtained from Saratov region, Russia. The structures were elucidated by interpretation of UV spectroscopic, MS, 1D and 2D NMR data. The relative configurations were determined by analysis of NOESY/ROESY spectra and coupling constants. The isolated compounds were evaluated for their inhibitory activity against bacteria, fungi and yeasts and showed pronounced antifungal activity. Both compounds are noticeably cytotoxic, being active against doxorubicin-resistant human leukemia cell line.