New cold-curing-sealant compositions based on poly[dimethylmethyl(hexafluoroalkyl)siloxane] rubbers

New fluorosiloxane cold-curing-sealant compositions based on low molecular weight poly[dimethylmethyl(hexafluoroalkyl)siloxane] rubbers of Russian production were developed. It was shown that the compositions meet the specification requirements for a serial VGF-2 sealant and possess improved resistance to TS-1 fuel.     

Singularly Perturbed Cauchy Problem in Which the Limit Operator has Multiple Spectrum and a Weak First-Order Turning Point

Differential Equations - Using S.A. Lomov’s regularization method, we construct an asymptotic solution of a linear Cauchy problem in which the limit operator has a weak turning point. The...     

Finite formation time of hadrons: the QGP signatures

In order to investigate the possible emergence of guark-gluon plasma, it is necessary to understand the properties of multiparticle production mechanisms in a more simple case than in relativistic collisions of heavy ions. The purpose of this article is to discuss some problems of the role of zone formation effectwhich are under active investigation nowadays. The formation length of hadron from particle-nucleus collision is derived and compared with those from relativistic ion collisions.     

Formation of Iron Silicides Under Graphene Grown on the Silicon Carbide Surface

Physics of the Solid State - The formation of iron silicide thin films under graphene grown on the silicon carbide surface is investigated. The thin films are synthesized by consecutive...     

Experimental study of the Bauschinger effect for anisotropic metals

The Bauschinger effect is characterized by the Bauschinger and Backhaus functions. The dependence of these functions on the direction of deformation of an initially anisotropic sheet material is studied. The experiments showed that these functions are independent of the direction, which confirms the model of isotropic Bauschinger effect.     

Results of operating LIA-2 in radiograph mode

The LIA-2 linear induction accelerator was developed at the Budker Institute of Nuclear Physics as an electron beam injector for a building induction accelerator at energy of 20 MeV, on the basis of which a complex for flash radiography will be developed. The LIA-2, which was started up in 2010, is currently used as an independent X-ray unit for raying objects with an optic thickness up to 70 mm in the lead equivalent. The effective diameter of the X-ray source is 0.6–0.7 mm.     

Electric-field-assisted self-assembly of colloidal particles

A method for formation of photonic crystals has been proposed. The method is based on convective deposition of colloidal particles onto vertical substrates in the presence of a direct-current electric field directed perpendicular to the surface of the formed film and an alternating-current electric field applied parallel to the substrate plane. The structure and optical properties of the prepared colloidal crystals have been investigated using scanning electron microscopy, high resolution small-angle X-ray diffraction, and optical spectroscopy.     

Conversion of synthesis gas into alcohols on supported cobalt-molybdenum sulfide catalysts promoted with potassium

The use of transition metal sulfides as catalysts for the synthesis of alcohols can solve the problem of catalyst resistance to sulfur. Catalysts based on molybdenum sulfide of different compositions (promoted with Co and K) were synthesized with the use of various supports (aluminum oxide, aluminum oxide modified with silicon oxide, Sibunit, and titanium silicate) and tested in the reactions of alcohol synthesis and the hydrofining of a mixture of thiophene with n-1-hexene. The dependence of catalyst activity in the synthesis of alcohols on support pore size was demonstrated. It was found that an increase in the potassium content of the active phase of a catalyst increased its activity in the synthesis of alcohols and decreased it in hydrodesulfurization and hydrogenation reactions. Transmission electron microscopy data made it possible to quantitatively evaluate the effect of a potassium additive on the morphology of the active phase; the hypothesis that potassium was intercalated between the layers of molybdenum sulfide was proposed.     

Manifestation of hydrogen bonds in raman spectra of potassium pentaborate

Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 55, No. 3, pp. 397–404, September, 1991.