Radiometry of dynamics of water-medium temperature profile by internal-wave transmission

Measurements of thermal radio emission at wavelengths of 3,9, and 30 cm are used to determine the temperature-distribution variations in the surface layer of a water medium by the excitation of internal waves in it.Scientific-Research Radio-Physics Institute. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 36, No. 3–4, pp. 216–222, March–April, 1993.     

Synthesis and reactivity of acyclic and macrocyclic uracils bridged with five-membered heterocycles

Replacement of terminal atoms of Br in 1,3-bis(bromopentyl)-5(6)-substituted uracils with 2-mercapto-5-methyl-1,3,4-thiadiazole, 2,5-dimercapto-1,3,4-thiadiazole, 2-mercaptoimidazole, and 2-mercaptobenzimidazoles resulted in a series of acyclic compounds and isomeric heterocyclophanes. Structures of macrocyclic regioisomers were unambiguously determined by NMR data. One of the regioisomers exhibits a hypochromic effect with respect to model compounds. The acyclic uracils obtained bridged with five-membered heterocycles are alkylated with methyliodide and methyl tosylate, and oxidated with m-CPBA, H₂O₂, and I₂.     

Quasiparticlelike peaks, kinks, and electron-phonon coupling at the (pi,0) regions in the CMR oxide La2-2x Sr1+2x Mn2 O7

Using angle-resolved photoemission, we have observed sharp quasiparticlelike peaks in the prototypical layered manganite La(2-2x)Sr(1+2x)Mn(2)O(7) (x=0.36,0.38). We focus on the (pi,0) regions of k space and study their electronic scattering rates and dispersion kinks, uncovering bilayer-split bands, the critical energy scales, momentum scales, and strengths of the interactions that renormalize the electrons. To identify these bosons, we measured phonon dispersions in the energy range of the kink by inelastic neutron scattering, finding a good match in both energy and momentum to the oxygen bond-stretching phonons.     

Phonon linewidths in YNi<Subscript>2</Subscript>B<Subscript>2</Subscript>C

Phonons in a metal interact with conduction electrons which give rise to a finite linewidth. In the normal state, this leads to a Lorentzian shape of the phonon line. Density functional theory is able to predict the phonon linewidths as a function of wave vector for each branch of the phonon dispersion. An experimental verification of such predictions is feasible only for compounds with very strong electron-phonon coupling. YN₂B₂C was chosen as a test example because it is a conventional superconductor with a fairly high T _c (15.2 K). Inelastic neutron scattering experiments did largely confirm the theoretical predictions. Moreover, they revealed a strong temperature dependence of the linewidths of some phonons with particularly strong electron-phonon coupling which can as yet only qualitatively be accounted for by theory. For such phonons, marked changes of the phonon frequencies and linewidths were observed from room temperature down to 15 K. Further changes were observed on entering into the superconducting state. These changes can, however, not be described simply by a change of the phonon linewidth.      

GC analysis of the gas filling of incandescent lamps: Determination of oxygen impurity in argon

Summary A sensitive GC method was developed to analyse O₂ (10–400ppm) in argon, by using Ar as carrier gas. A sampling method was developed for lamp analysis, and the O₂ impurity content in the gas filling of incandescent lamps was measured. The results of the GC and MS measurements were in good agreement.     

Some phosphorus-containing esters of N-hydroxyalkylpyrimidones

Conclusions Some esters of phosphorus acids and N-(-hydroxyethyl)-4-pyrimidones were synthesized.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2010–2012, September, 1971.     

Several chemical transformations of N-(β-hydroxyethyl)uracils

Conclusions Several chemical transformations of N-(-hydroxyethyl)uracils were studied, among them reactions with thionyl chloride and dimethyl sulfate.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2811–2812, December, 1968.