Bulletin of the Lebedev Physics Institute最新文献

Electric currents arising in a nonlinear transmission line during the propagation of an electromagnetic KdV soliton are analyzed. An analytical expression for calculating the current soliton is obtained. It is shown that it has a classical profile, which in the approximation of small amplitudes is described by the soliton solution of the KdV equation. The voltage profiles between the ends of a section of one of the line conductors are also calculated; they are shown to have the form of symmetric bipolar pulses.

Probably, annihilation of atoms from magnetic monopoles (2.4 GeV) and their transitions in the Lyman series (1.8, 2.1, and 2.25 GeV) could result in a gamma-ray excess in our galactic center, which was observed by the Fermi observatory. Monopoles of GeV energies can form in the magnetospheres of magnetars and be blown out of them. At the galactic scale, atoms from magnetic monopoles (g⁺g^‒) are part of dark matter.

We propose a simple noncontact spectral method for determining the presence or absence of milk pasteurization. The method is based on the pasteurization temperature dependence of luminescence spectra of milk excited by ultraviolet radiation in the wavelength range of 300‒420 nm.

The experimental results of irradiation of the isotopically enriched [¹³⁵Ba]BaCO₃ targets by protons with an initial energy of 30 MeV are presented. The cross-sections of lanthanum and barium radioisotopes formed as a result of ¹³⁵Ba(p, x) nuclear reactions were measured and compared with theoretical data for the first time. The possibility of production of ¹³⁵La and ¹³³La for their further medical use was shown.

The survival efficiency of dust during the interaction of dusty interstellar clouds with shock wave was studied. We have found that in the adiabatic destruction of small clouds, the dust grains belonging to the cloud are separated by size along the cloud motion: large dust grains remain far behind the gaseous clumps of the cloud, and small grains are entrained by the cloud. In large radiatively cooled clouds, a significant part of dust is contained and saved inside dense cold clumps of the cloud independently of the grain size.

We report investigation of the resonant process of electron impact induced charge transfer in the inert gas systems Ar + Xe⁺ and Kr + Xe⁺. Along with this, the reaction of the formation of charge-transfer ions XeRg⁺ in triple collisions Rg + Xe⁺ + e, occurring due to nonadiabatic transitions, is studied. These processes are compared with the efficiency of dissociative electron impact excitation of ArXe⁺ and KrXe⁺ ions, accompanied by the formation of Ar⁺ and Kr⁺ ions, under conditions of plasma equilibrium in nuclear motion.

The transformation of elliptical polarization in a layer of azobenzene-containing amorphous polymer is calculated. The dependences of the Stokes parameters for the propagation of a light wave deep into the layer are obtained. It is shown that the light-induced change in absorption leads to a decrease in the ellipticity of the light wave, which, in turn, slows down the rotation of the polarization ellipse. The obtained results are important for optical writing of phase structures in polymers.

The radio emission of the electron charge excess from an extensive air shower (EAS) is calculated taking into account the geomagnetic field in a kinetic model. Unlike the previous macroscopic models, the emission of each excess electron of the shower disk is calculated taking into account their longitudinal and transverse current caused by the Lorentz force. The spatial distribution of excess electrons in the disk, their energy spectrum, multiple scattering, and evolution of the disk along the EAS track is taken into account.

A laser ablation method for the formation of light-trapping pyramidal microstructures on the surface of monocrystalline silicon is considered. The optimal parameters for obtaining such structures were determined, their chemical composition was investigated, and measurements of the specular reflection and transmission in the spectral range of 700–5000 cm^–1 were performed.

We report the results of the dissolution dynamics of germanium nanoparticles synthesized by laser ablation in distilled water and isopropanol. It is shown that germanium nanoparticles dissolve almost completely in distilled water within 24 h. A comparative experiment is performed on laser heating of distilled water and an aqueous germanium nanoparticles solution with an average nanoparticle size of ~130 nm and a concentration of 0.8 mg/ml, which makes it possible to construct heating and cooling curves. Under conditions of the experiment, the heating of the nanoparticle solution increased by 36% compared to distilled water. The obtained results can be used in photohyperthermia technologies for the treatment of cancer tumors.