Fragmentation of peptide molecules grazing an organic surface at velocities below the Bohr value is experimentally and theoretically studied. The process of fragmentation of the arginine (Arg) and arginine-2 (Arg—Arg) peptide molecules grazing at respective velocities of $1.95\cdot10^6$ and $1.44\cdot10^6$ cm/s the surface of a perfluorocompound is thoroughly analyzed. Calculations are made within the framework of the resonance fragmentation model previously proposed by the authors. The theoretical results obtained agree well with the experimental data.
Show AbstractIn a constant magnetic field in the 5-dimensional Kaluza—Klein model, the photon—graviton conversion coefficient is calculated. It is demonstrated that the presence of the fifth dimension does not affect the coefficient form as compared to the 4-dimensional case.
Show AbstractA spatially two-dimensional axisymmetric model of heating steel cylindrical samples in solenoidal inductors is considered. With the aid of the developed model, the boundary effects of weakening of heating, which occur near the ends and are related to the magnetic field scattering, are studied. Various methods for heating optimization in order to eliminate the boundary effects are suggested.
Show AbstractThe ingenious investigation in physics of ion—atom collisions instituted at the Research Institute of Nuclear Physics, Moscow State University, is described. Long-term data obtained in this field by a group of researchers headed by Prof. V.S. Nikolaev are presented.
Show AbstractThe differential and integral angular distributions of the $^{14}$N and $^{16}$О ions with initial energies $\varepsilon_0\approx{}$32, 78, 110, and 330 keV/nucleon scattered in Al, Cu, Ag, and Au films from ~ 0.3 to 2.3 fim in thickness have been measured. Universal relationships between the half-widths of these distributions and the target thickness are obtained. Based on the analysis of the angular distributions of the particles scattered in the thinnest films, the magnitude and the energy dependence of the "effective charge" $i_{\rm sc}$, whose introduction into the Moliere—Bethe theory [2—4] makes it possible to take account of the effect of ion charge exchange in the course of scattering, are found.
Show AbstractOn the basis of experimentally measured charge distributions $F_i$ in the ion beam after traversing a gaseous (nitrogen) target and thin celluloid films differing in thickness, the charge-exchange cross sections of fast ions are calculated. The results of calculating and measuring the charge distributions at the ion velocities $V=3.6$ and $5.5$ amu as a function of the target thickness t are presented. The dependence of the equilibrium charge $i_{\rm eq}$ and the equilibrium target thickness $t_{\rm eq}$ both on the velocity and initial charge state of the incident ions, on the one hand, and the thickness and state of aggregation of the target, on the other, are analyzed.
Show AbstractWithin the framework of the method of coupled kinetic equations suggested earlier by the authors, the behavior of the average (effective) charges of fast multiply charged ions passing through matter under nonequilibrium conditions is investigated. The calculated stopping parameters of fast oxygen ions in thin carbon films agree with the recent experimental data.
Show AbstractThe effect of the final-state particle interaction on the dependence of the differential and total single-ionization cross sections on the impinging ion charge is considered. It is demonstrated that the reason for the weak charge dependence of the single-ionization cross sections is the final-state interaction of charged particles.
Show AbstractA model of a cyclotron-autoresonance maser with an open interference waveguide is considered. The possibility of loss discrimination of contradirectional waves is demonstrated.
Show AbstractScattering of light by aqueous-mi cellar polyelectrolyte solutions of various concentrations and polyion chain lengths is studied. The polyelectrolytes studied are found to affect the micelle formation process. The influence of the polyion chain length and polyelectrolyte concentration on the structure of the micelle—polyelectrolyte complex being formed is established.
Show AbstractTo compute by the Monte Carlo method the light scattering by a whole blood layer, with due regard for the formation of linear cell aggregates whose length varies in the course of aggregation in accordance with the gamma distribution, a model and a computer program are developed. The time dependence of the scattering signal intensity for various scattering albedo values is computed and the aggregation rate is estimated. While linear cell aggregates are being formed, the computed aggregation kinetics results agree well with the experimental data.
Show AbstractA mode with spontaneous periodic polarization switching of the Yb-doped double-clad fiber laser radiation was experimentally observed. Switching between two mutually orthogonal linear polarizations arose at pump powers exceeding some critical value, and the period of switching decreased as the pump power increased. At the pump power higher than the threshold but lower than the critical value, the Yb-doped fiber laser output radiation was linearly polarized (the degree of polarization was 0.95±0.03).
Show AbstractThe parameters of the acoustic jet arising at the open end of a waveguide in which an intense harmonic sound field sets in in the form of a standing wave at the waveguide resonant frequency are experimentally studied. Earlier developed methods of recording and analyzing the velocity field are used. The spatial development of the jet near the waveguide open end at resonant frequencies 175 and 358 Hz and sound pressure 160 dB in the incident wave is studied. The jet velocity and its oscillatory component are quantitatively estimated.
Show AbstractПроведено моделирование взаимодействия сфокусированного электронного зонда с катодолюминесцирующим веществом. Выполнены расчеты светового транспорта в материале объекта и в эллипсоидальной системе, коллектирующей свет. Показана возможность пространственной сепарации излучающих микрообъемов люминесцирующих тел.
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