Calculation of number of tractions forming at macrodestruction of polymer films

Analysis of mechanical properties of polymer films is carried out for different ways of deformation including scaling and pulling off. An expression is obtained for the number of tractions, which may arise in a polymer film at various deformations.     

Proton distribution at low altitudes in near-equatorial latitudes according to satellite experiments: The dynamics of proton fluxes

The data obtained on the ACTIVE, SAMPEX, and TIROS-N satellites are used to study the dynamics of low-energy (from tens of keV to several MeV) proton fluxes in the region of the geomagnetic equator (L < 1.15) at low altitudes (up to 1000 km). The dependence of the fluxes on the local magnetic time is presented. A number of magnetic disturbances in November–December 1978 are analyzed to illustrate the dependence of the flux on the geomagnetic activity level. The results obtained allow the conclusion that the ring current is one of the main sources of protons at low altitudes in near-equatorial latitudes.     

Specific features of the distribution of protons at small altitudes in near-equatorial latitudes according to data of satellite experiments. I. Energy spectrum

The spectra of protons with energies from 10 keV to 1 MeV as measured in experiments conducted at satellites and the MIR orbital station are presented. These data were obtained in the area of the geomagnetic equator at L < 1.15 and at altitudes up to 1000 km. The proton spectrum was determined during periods of geomagnetic perturbations and quite periods. These spectra were approximated using a kappa-function. The proton spectra in the near-equatorial area and in the ring current are compared. The proton’s life time in the near-equatorial area is estimated, taking into account charge exchange and Coulomb scattering. It is confirmed that the ring current is a main source of protons in the near-equatorial area at low altitudes.     

Optimal penetration of a liquid jet into an obstacle

The velocity distribution and cross-sectional area along a jet which will assure maximum depth of penetration are found for a given jet energy within the framework of the hydrodynamic theory of liquid jet penetration into an obstacle. Also found is the velocity distribution along the jet which will assure ultimate tension of its elements upon approaching the obstacle. The possibility is exhibited of applying the theory elucidated to construct cumulative charges with elevated punch-through capacity.     

Synthesis and transformations of 3-allyl-7,10-dimethyl-2-sulfanylidene-2,3,5,6-tetrahydrospiro[benzo[<Emphasis Type="Italic">h</Emphasis>]quinazoline-5,1′-cyclopentan]-4(1<Emphasis Type="Italic">H</Emphasis>)-one

Ethyl 4′-amino-5′,8′-dimethyl-1′H-spiro[cyclopentane-1,2′-naphthalene]-3′-carboxylate reacted with allyl isothiocyanate to give 3-allyl-7,10-dimethyl-2-sulfanylidene-2,3,5,6-tetrahydrospiro[benzo[h]quinazoline- 5,1′-cyclopentan]-4(1H)-one. Reactions of the latter with alkyl halides and hydrazine hydrate and subsequent transformations of the products afforded a series of new benzo[h]quinazoline derivatives containing an allyl group in the 3-position.     

Fluorescent analysis of the structural changes of human serum albumin induced by low temperatures in water-dimethyl sulfoxide solutions

Structural changes in human serum albumin (HSA) induced by low temperatures in water-dimethyl sulfoxide (DMSO) solutions were studied by fluorescent spectroscopy. The emission, synchronous, and isopotential synchronous spectra (3D spectra) of the HSA were analyzed. It was shown that protein does not undergo drastic structural changes in the fast freezing/defrosting mode in solutions of up to 20% DMSO but becomes more compact.     

Quasiunconditional Basis Property of the Faber–Schauder System

Ukrainian Mathematical Journal - We prove that, for any 0 &lt; ?? &lt; 1, there exists a measurable set E?? ? [0, 1], mes (E??) &gt; 1...     

Modeling of material properties after ultrashort laser and XUV excitation

By means of first principles calculations, we studied the possibility of manipulating structural properties of different materials via excitation with intense femtosecond laser or extreme ultraviolet (XUV) pulses. For silicon and boron-nitride nanotubes, we performed ab initio molecular dynamics simulations using the code CHIVES, developed in our group, to describe their laser-induced structural dynamics. For both materials, we determined the damage thresholds. We also investigated the structural response of magnesium and copper to ultrashort XUV excitation. For this purpose, we performed frozen-phonon calculations based on all-electron density functional theory and allowed the possibility of core-hole excitation. We found that Cu undergoes bond hardening and Mg bond softening upon creation of core holes and hot electrons, where we defined the bond strength by the vibrational frequencies.     

The effect of electron irradiation on the optical properties of the natural armenian zeolite-clinoptilolite

Infrared (IR) absorption and luminescence in chemically and radiation-modified natural Armenian Zeolite (clinoptilolite) samples have been studied. The luminescence was studied in 390–450 nm and 620–710 nm wavelength bands, and the IR measurements were carried out in the 400–5400 cm⁻¹ range. It is shown that the luminescence intensity depends on the content of pure clinoptilolite in the samples and, probably on the distribution of “passive” luminescence centers over Si and Al sites that became “active” under radiation or chemical treatment. The samples of electron irradiated clinoptilolite have higher luminescence intensity than the chemically and thermally treated ones. A decrease in the intensity of IR absorption bands at 3550 cm⁻¹ and 3650 cm⁻¹ was found after irradiation.