Russian Physics Journal最新文献

The paper studies hypereutectoid steel rails after a continuous operation, using transmission electron microscopy investigations of their fine structure, a comparative analysis of quantitative parameters of the rail structure morphology at a different distance from the surface of the rail head, along the central axis and spherical radius of the gauge corner. All experiments are conducted on the Russian Railways experimental ring.

A new Tutton’s salt of Ammonium Zinc Nickel Sulphate Hexahydrate—AZNSH is proposed, which crystallizes in the monoclinic crystal system with the space group of P2₁/c. The new crystal formula is (NH₄)₂Zn_xNi_1–x(SO₄)₂.6H₂O with a formula weight of 397.45 at 296(2) K. The crystal formula ofH₂₀N₂Ni_0.59O₁₄S₂Zn_0.41 gives the following lattice data: 6.2412(3), 12.4915(6), and 9.2080(5) Å for the a, b and c lattice parameters, whereas β = 106.941 (2)° which is grown by slow evaporation solution growth method. The frequency enhancement by the AZNSH-coated diodes and the sensor efficiency of the specimens are reported. The new structure formulation is supported with the data on the lattice, electronic structure and with the crystal-sensor data.

The present study comparatively investigates the UV and e‑beam degradation of paracetamol to determine final residual products after its UV and pulsed e‑beam treatment. Using an experimental setup RSLS, paracetamol was irradiated by a vertical electron beam (a pulse duration of 2 ns, an average electron energy of 170 keV, a current density of 130 A/cm², and a repetition rate of 1 Hz) from a RADAN-300 generator. Four methods, including UV-VUV photolysis (KrCl, Xe₂, and UVB-04) and e‑beam radiolysis, were used to induce the paracetamol degradation from 1×10⁻⁴ to 4.6×10⁻⁷ mol×L⁻¹ when the drug was dissolved in water or deposited to TLC plates in a solid state. A spectral-luminescent paracetamol transformation under UV and e‑beam irradiation was studied. New experimental data were obtained on the total phenol content (TPC) in a mixture of paracetamol transformation products in water under irradiation. Moreover, the lowest TPC value of 9.76 ± 0.82 mg GAE/g was observed in an aqueous solution of paracetamol irradiated with a Xe₂ excilamp for 128 min. It was found that the conversion reached 92 and 93% after irradiation with e‑beams and the Xe₂ excilamp, respectively. A solid-phase paracetamol transformation product, preserved after 128 min of UV irradiation, was detected using thin layer chromatography. The available results suggest that, apparently, after Xe₂ excilamp (2.4 kGy) and e‑beam (1.47 kGy) treatment, paracetamol that may be present in the treated wastewater will be in the form of residual phenolic compounds.

The proposed automated soil and climate monitoring system helps agricultural enterprises to adopt modern planning and control methods. Designed for Siberian conditions, autonomous, waterproof probes collect data as specified by the user. The web interface provides an access to readings, notifications, and processed results via tables, charts, and maps. Using low-cost components, the system provides the communication range of 3 to 7 km. Its deployment at the Siberian Botanical Garden has helped to maintain the best conditions for plants and significantly reduced insect-borne disease risks.

The paper proposes the model of motion of monoatomic A and B steps on the vicinal Si(100)-2×1 surface that accounts for the formation of Si dimers in kinks in a consequence of elementary processes of the adatom attachment to the kink, detachment of a single atom from the kink, dimer dissociation, and Si adatom migration along the step edge. It is shown that in the case of permeable A steps and impermeable B steps, the rapid formation of biatomic steps observed in the experiment, occurs even in the absence of both conventional and inverse Ehrlich–Schwoebel barriers.

Zirconolite (CaZrTi₂O₇) is the best suited material for radioactive waste immobilization and management. Its synthesis is a cost- and time-demanding process. In this work, a ceramic material, primarily containing the zirconolite phase, is for the first time synthesized within a few seconds. Its synthesis is performed in air by heating a mixture of CaTiO₃, ZrO₂ and TiO₂ powders using a high-power, fast-electron beam. The irradiation regimes are used, during which all of the mixture components melt, resulting in a liquid-phase, high-rate synthesis of a new ceramic material. The zirconolite phase accounts for more than 80% of the synthesized ceramics and exhibits low porosity. It is shown that a thermal annealing treatment of the resulting ceramic product in a high-power, fast-electron beam allows considerably increasing the zirconolite phase content in it.

A generalized spectroscopic criterion for assessing excited-state aromaticity is developed and applied to determine the aromaticity of the low-lying singlet excited states (S₁, S₂, S₃, and S₄) of porphin. Predictions from spectroscopic criterion are validated by magnetically induced current calculations. The analysis performed reveals that magnetic dipole-allowed transitions can be used for a fast, qualitative prediction of excited-state aromaticity.

This work focuses on the improvement of the global navigation satellite system reflectometry (GNSS-R) methods of the underlying terrestrial surfaces. An integrated approach based on a multipath GNSS‑R is applied to determine the parameters of near-surface layered structures, including ice and snow and continuous forest covers. At the same time, experimental measurements of amplitude-time dependencies of signals from navigation satellites are processed by fast Fourier transform and then analyzed using a mathematical apparatus based on the multipath reflection model within geometric optics. In combination with the GNSS‑R technique, numerical modeling of near-surface layers, is based on local meteorological data. This allows assessing not only the current state of layered near-surface structures, but also predicting their dynamics.

The results of the studies into structural evolution of the aluminum alloy 2024 samples subjected to friction stir processing after annealing and quenching/aging are presented. It is shown that despite the differences in mechanical characteristics between the heat-treated samples, similar microstructures formed in their stir zones with close values of ultimate tensile strength and yield stress are observed. The stir zone consists of solid solution grains 1–2 μm in size and S and S′ Al₂CuMg < 100 nm-sized precipitates distributed over the joint zones. Monitoring a force resisting the tool movement allows establishing that the heat-treated samples demonstrate different degrees of plasticization during friction stir processing.

The paper proposes a geometrical model of classsical spinning particle, whose quantization corresponds to the unitary irreducible continuous helicity representation of the Poincaré group. It is shown that the class of gauge-equivalent trajectories of the particle forms a cylindrical surface in 4D Minkowski space. This fact allows deriving equations of motion for time-like particle trajectories.