Distinctive features of variation in the thermal structure of impinging gas jets

Turbulent structures occurring in impinging air jets in both original and excited states are identified by means of processing the sequences of thermal images (thermal videofilms). It is assumed that the structure in a jet is a flow region in all whose points (elements) the temperature as a control parameter varies with time in accordance with a single dynamic law. An analysis of the obtained two-dimensional distributions of the characteristic frequencies of temperature fluctuations in impinging air jets makes it possible to reveal and to determine the generation and the localization of structure regions, the time intermittence effect, the difference in the nature of structure formations, and the structure formation effect on heat transfer.     

Catalytic Cracking of Cyclohexane and 1-Hexene Mixtures on Mono-, Bi-, and Tri-Zeolite Catalysts

Kinetics and Catalysis - The effects of temperature (540–640°C), weight hour space velocity (1.0–7.0 h–1), and steam : raw material ratios (0–2.5) on the yield of...     

In situ investigation of ferromagnetism in magnetic nanolayers at room temperature

Ultrathin iron layers on different substrates and a Dy_{1 ? x} Ni _x /Nibilayer have been investigated in situ using the magneto-optical Kerr effect. Ferromagnetic ordering in the Dy_{1 ? x} Ni _x /Nistructure at room temperature has been established. A technique for estimating the thickness of the iron/silicon interface is proposed.     

Photophysical properties of the extract of endometallofullerenes La@C2n inortho-dichlorobenzene. Picosecond laser photolysis

The kinetics of relaxation of optical anisotropy induced by polarized light in endometallofullerenes La@C_2n inortho-dichlorobenzene was studied by picosecond laser photolysis. Decay of the optical absorption signal due to the excited states of La@C_2n follows the biexponential law with two values of relaxation time:t ₁=35±3 ps andt ₂=1100±200 ps. The lifetimet or decay of the optical anisotropy is 19±5 ps and determined by the orientational diffusion of La@C_2n . The experimentally determined lifetime of optical anisotropy agrees satisfactorily with the value yielded by the theoretical model of orientational diffusion under slip boundary conditions at the interface of the La@C_2n molecule with the solvent. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya No. 10, pp. 1921–1923, October, 1999.     

Kinetics of the geminal recombination of aromatic radicals in liquid polymers

Conclusions Laser photolysis was used to determine the kinetics of the geminal and bulk recombination of radical pairs formed in the transfer of a hydrogen atom from p-cresol to triplet benzophenone in liquid polymers. In a very viscous polymer matrix containing a nonviscous plasticizer, the bulk recombination of the low-molecular-weight radicals proceeds at a very high rate as in nonviscous liquids.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 437–438, February, 1987.     

Aromatization of a C3–C4 alkane mixture over Zn-pentasil modified with tin and lead

Modification of Zn-containing H-ZSM-5 pentasil by tin and lead reduces the yield of C₁₀₊ aromatic hydrocarbons from alkanes C₃–C₄. The high selectivity of formation of the aromatization products is retained.