The influence of side substituents in α-amino acids on their sorption by a cation-exchange membrane

The isotherms of sorption of ornithine, lysine, arginine, and histidine by an MK-40 membrane were obtained by the method of variable concentrations. The influence of the geometric parameters of side groups in the basic amino acids and pH on the degree of their absorption by the membrane was studied. The formation of doubly charged amino acid cations in the membrane phase when membranes in the H⁺ form were used was substantiated IR spectroscopically. The distribution coefficient was found to depend linearly on the size of amino acid side groups. The dependence of interphase surface tension at the membrane-solution interface on the degree of membrane filling was indicative of the formation of sorbate associates in the membrane phase.     

The Absorptivity of a Nanocomposite Layer with Spherical Metal Inclusions

The dependences of the absorptivity of a nanocomposite layer (a dielectric matrix with spherical metal inclusions) on the frequency, the volume fraction, the size of inclusions, the thickness of the layer, and the angle of incidence of the wave on it are studied. It is shown that the particular features of optical characteristics are related with the plasmon resonance in nanoparticles and the resonant-frequency dependence of the dielectric permittivity of the composite medium. The values of film parameters and frequency intervals in which the incident radiation is absorbed almost completely are found.     

Crystal structure of N-(3-nitrocinnamoyl)-N-(2-chlorophenyl)hydroxylamine

All-Union Scientific-Research Institute of Chemical Reagents and Specially Pure Chemicals. Translated from Zhurnal Strukturnoi Khimii, Vol. 31, No. 5, pp. 161–164, September–October, 1990.     

Creep of lead alloys. I

The effect of traces of Sb, Te and Cu on the creep of lead under various stresses () atroom temperature is considered. The greatest sensitivity to the value of is exhibited by Pb itself, and the least by the Pb-Sb-Te-Cu alloy, in which the creep rate is low over a wide stress range. Tests on alloys treated in such a way as to produce the same grain size show that the addition of Sb, Te, and Cu reduces the creep rate of lead. The greatest influence is exerted by the addition of copper and the least by the addition of antimony. For all the materials studied the creep rate falls with increasing grain size. This influence is the greater, the lower the value of . For alloys annealed at the same temperature and possessing a grain size smaller than that of lead, in the case of small values of the beneficial effect of alloying is partly masked by the grain-size effect.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, Vol. 16, No. 9, pp. 77–81, September, 1973.     

Excitation of Electroluminescence by a Rotating Electric Field

The principle of operation of an electroluminescence capacitor (ELC) in which a powder zinc sulfide electroluminophor is excited by threephase voltage is described. Rotation of the electric field intensity vector in a luminophordielectric layer allows a substantially greater number of energy barriers to be involved in the collision processes in the luminophor grains than in a conventional ELC. This provides the possibility of retarding the ELC degradation: at the same initial brightness the time of its halfdecay increases several times.     

Luminescence instability of films and new organic light-emitting diodes based on zinc complexes with tetradentate Schiff bases: Influence of heating and laser irradiation

Organic light emitting diodes (OLEDs) based on zinc complexes with tetradentate Schiff bases — ZnSB [H₂SB =H₂Sal1, H₂Sal2 (derivatives of salicylic aldehyde); H₂MO1, H₂MO2 (derivatives of o-vanillin)] display reversible and irreversible electroluminescence (EL) instability. The reversible instability occurs after switching voltage on and the irreversible instability produced by UV light irradiation, heating, and aging under the ambient conditions. In view of the results obtained, the first type of instability is associated with the trap filling processes and the second type appearing at heating is possibly attributed to the changes in the interface domains. Recommendations for the evaporation and capsulation conditions are provided.     

Degradation of organic light-emitting diodes based on different-ligand complexes of terbium (III) salicylate and 2-phenoxybenzoate

Degradation (D) of organic light-emitting diodes (OLEDs) based on new different-ligand complexes of terbium salicylate (Tb(Sal)₃(TPPO)₂) and 2-phenoxybenzoate (Tb(pobz)₃(TPPO)₂) with triphenyl phosphinoxide (TPPO) was studied. Initial reversible D is associated with charge carrier trap filling. A temperature increase, applied stress relief, and short-term irradiation with UV light lead to trapped charge carrier release and electroluminescence (EL) intensity recovery. During strong heating, irreversible D is observed after the recovery; this D requires in addition an electric field (EF). Intense UV light causes D without EF. The use of ac bias voltage eliminates reversible D, and sealing retards irreversible long-term D.