Electron-Stimulated Hydrogen Desorption from Nickel and Palladium

New experimental data are presented on the radiation-stimulated diffusion of hydrogen in metals, in particular, nickel and palladium, under the action of a 30-keV accelerated electron beam. Hydrogen desorption rates from nickel and palladium are determined for thermal and electron beam heating; a substantial shift of the thermal gas-desorption peaks to the low-temperature range is detected upon radiationinduced heating. The presence of an internal hydrogen atmosphere is shown to create favorable conditions for the vibrational-translational exchange (V–T exchange), non-equilibrium redistribution, and desorption of hydrogen from a solid upon irradiation. Accelerated hydrogen migration stimulated by electrons with an energy below the defect-formation threshold is explained at a qualitative level. First-principles calculations of the electronic structure of the metal–hydrogen system reveal that plasmons are also an efficient mechanism for radiation-energy dissipation over the whole crystal.     

Quality Characterization of CVD-Synthesized Graphene Films by Scanning Probe Microscopy

Doklady Physics - The problem of efficiency of using electrical properties for characterizing graphene structures obtained by chemical vapor deposition and formed on substrates of various materials...     

Five-membered 2,3-dioxo heterocycles: XLVIII. Reaction of 3-aroyl- and 3-heteroyl-2,4-dihydro-1<Emphasis Type="Italic">H</Emphasis>-pyrrolo[2,1-<Emphasis Type="Italic">c</Emphasis>][1,4]-benzoxazine-1,2,4-triones with 3-amino-5,5-dimethyl-2-cyclohexenone

3-Aroyl- and 3-heteroyl-2,4-dihydro-1H-pyrrolo[2,1-c][1,4]benzoxazine-1,2,4-triones react with 3-amino-5,5-dimethyl-2-cyclohexenone to give 3-aroyl-4-hydroxy-1-o-hydroxyphenyl-6,6-dimethyl-2,2,3,4,5,5,6,7-octahydro-1H-indole-3-spiro-2-pyrrole-2,4,5-triones. The structure of the products was proved by X-ray analysis.Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 9, 2004, pp. 1405–1409.Original Russian Text Copyright © 2004 by Mashevskaya, Duvalov, Tolmacheva, Aliev, Maslivets.This study was performed under financial support by the Russian Foundation for Basic Research (project nos. 01-03-32641 and 02-03-96411).For communication XLVII, see [1].     

Choice of optimum conditions of emitter preparation for X-ray fluorescence analysis of aerosols

The nonuniformity of aerosol distribution over filter surface was studied. It was found that the distribution depends on the properties of the studied object and on the sampler type: particle concentration is often higher in the center of the filter, but in some cases, they shift to the edges; the uniform distribution of particles is observed rarely. It was shown that, if the emitter in X-ray fluorescence analysis (XRF) is a disk 3 cm in diameter cut from the center of a filter 5 cm in diameter, the systematic error of the results of analysis may be higher than 0.30. Recommendations on the choice of the conditions of sampling aerosols and emitter preparation are formulated. If these conditions are met, the results of XRF analysis of nonuniform filters are characterized by s_r = 0.05, which satisfies the admissible error.     

2,3,3-trimethyl-3h-pyrrolo[3,2-c]quinolines and polymethine dyes based on them

2,3,3-Trimethyl-3H-pyrrolo[3,2-c]quinoline and its 8-methoxy derivative were obtained from methyl isopropyl ketone 4-quinolylhydrazones. These bases form quaternary salts at the azine nitrogen atom, from which polymethine dyes were obtained. The changes in the absorption spectra of the dyes in solutions with various acidities were examined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 948–951, July, 1982.     

Effect of the physical state on tearing of amorphous polymers

On the assumption that the strength of linear amorphous polymers is determined by the efficiency of molecular interaction and the degree of orientation in a region adjacent to the tip of a tear, the temperature dependence of both indicated factors is described in the temperature range encompassing the rigid, high-elastic, and viscous flow states. On the basis of a comparison of the indicated temperature dependences, a -T curve for real polymers is proposed and confirmed by experiment. The dependence is characterized by a pronounced peak in the region of transition from the rigid state to the high-elastic state and is of exponential type in the temperature range encompassing this state.Mekhanika Polimerov, Vol. 1, No. 4, pp. 100–105, 1965     

5-Hetaryl-substituted 2-methyleneindolines and polymethine dyes based on them

2-Methyleneindolines containing benzazole residues at the 5-position were synthesized and polymethine dyes were obtained from them. The bathochromic shifts induced by the introduction of heterocyclic residues into indocyanines exceed the similar shifts induced by the same heterocycles in thio and quinocyanines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1050–1054, August, 1990.     

Application of microemulsions for the extraction of <Emphasis Type="Italic">o</Emphasis>-phthalate esters from soil with subsequent separation of microemulsions,simultaneous preconcentration,and gas chromatographic analysis of target components

The possible application of microemulsions as extractants for the extraction of o-phthalate esters from soils with the subsequent breakdown of microemulsions, simultaneous preconcentration of dialkhylphthalates in the organic phase, and their following gas chromatographic analysis with mass-spectrometric detection is demonstrated. The preconcentration factor was 18. The method is characterized by low detection limits, good selectivity, and reproducibility.