Volume 44, Nº 12 (2025)

Within the framework of the quasiclassical trajectory method on semiempirical diabatic potential energy surfaces, we have considered the existence regions for transcomplex recombination RCs⁺ + Br^– → CsBr + R (R = Kr, Xe, Hg) in the space of kinematic parameters for collision energies from 0.1 to 2.5 eV. In contrast to the existence regions for direct three-body recombination Cs⁺ + Br^– + R → CsBr + R (R = Kr, Xe, Hg) we studied in previous works, the existence regions for transcomplex recombination at low collision energies (up to 0.3 eV) sometimes exhibit chaotic structure. We have proposed a quantitative measure of chaoticity of an existence region for transcomplex recombination based on the combinatorics of binary matrices (all the entries of which are equal to zero or one). The local minima of the opacity functions of transcomplex recombination at low collision energies are formed precisely due to chaotization of the existence regions for recombination.

The paper presents the results of experiments on the ignition of samples by high-current beam of nanosecond duration of energy-saturated composites (ENC). ENC based on porous silicon with two oxidizing agents – barium perchlorate and sodium perchlorate, and two additives – graphene and fullerites. It was found that, with some probability, the additives are peculiar triggers of phase transformations in brass caps that contained the pressed energy-saturated composite.

The energy budget is calculated for the elementary steps involved in the reaction between carbon oxide and the gold hydride (H–Au₃–H)^– producing (HCO–Au₃–HCO)^–. The hydride (H–Au₃–H)^– is formed by adsorption of H₂ on the simplest negatively charged gold cluster, Au₃ ^–. A detailed mechanism is proposed for reaction between O₂ and (HCO–Au₃–HCO)^–, and the energy budget is calculated for the elementary steps involved in the production of (Au₃–CO)^–, H₂O, and CO₂. Based on the calculated results, an explanation is proposed for the experimental data on interaction of hydrogen, carbon oxide, and oxygen with gold nanoparticles deposited on pyrolytic graphite. Since the gold nanoparticles located on graphite are negatively charged, the calculations are performed accordingly for negatively charged gold-containing particles.

Measurements of the flame propagation speed of H₂/F₂/O₂/He mixtures were carried out. The effect of the concentration of molecular hydrogen on the combustion rate has been studied. The lower concentration limit of hydrogen for the existence of combustion under the specified experimental conditions has been obtained. A model of chemical and gas-dynamic processes for calculating the combustion rate has been developed and the calculation results have been compared with the obtained experimental data. Additional processes are proposed, which can improve the coincidence of calculated and experimental data.

For the first time, conditions have been found under which a unique combination of anticancer properties of Keggin heteropoly acids (KHPA) and their simplest salts is observed – high and selective cytotoxic activities (at the level of IC₅₀ < 100 μM and IS₅₀ > 3). To describe the nature of the observed dependencies, a molecular model of pore formation in bilayer lipid membranes by multiply charged anions was proposed. Analysis of the consequences arising from the proposed model led to the conclusion about the possibility of increasing the anticancer activity of KHPA by increasing their anionic charges.

The article shows the possibility of using the IR - Fourier spectroscopy method to identify foreign particles found in the gas-air tract of gas-turbine engines of aircraft. The results of a comparative analysis of their (particles) IR- spectra, IR-spectra of various rubber technical parts, polymer products and materials used in their manufacture confirmed that the identified particles are fragments of carbonized rubber from aircraft tires as a result of exposure to high temperatures.

Carbonyl oxides, or Criegee intermediates, are chemically active compounds that readily react with other atmospheric components, promoting the formation of OH and CH₃ radicals, nitrogen oxides, aldehydes, hydrogen peroxide, and various acids. In this work, we consider the physicochemical processes involving electronically excited states of three simple Criegee intermediates: CH₂OO, CH₃CHOO and (CH₃)₂COO. In addition to the ground state S₀, the calculation scheme included four low-lying excited electronic states: S₁ (nπ*), S₂ (ππ*), S₃ (nπ*), and S₄ (ππ*). It was found that the optical transitions S₀→S₂ and S₀→S₄ have comparatively large dipole moments; therefore, they are observed in the absorption spectra of these compounds and play a key role in atmospheric processes. Analysis of the PES structures corresponding to these excited states, their relative arrangement, local minima and maxima, as well as intersection points, showed that under photoexcitation in typical atmospheric conditions the most probable chemical reaction is direct O—O bond cleavage in the S₂ (ππ*) or S₄ (ππ*) states, leading to oxygen atom detachment O(¹D). Under more complex conditions, when the molecule possesses a sufficient amount of internal energy, transitions to lower-lying electronic states are possible, whose equilibrium geometries strongly differ from the initial ones. This results in the release of a large amount of energy and subsequent relaxation of the molecule into the ground electronic state S₀.

In₂O₃ nanopowders were synthesized by the hydrothermal method using various solvents: water, alcohol and ethylene glycol. The nature of the solvent determines the phase composition, structure and morphology of the material, which affects the electrophysical properties of indium oxide. In₂O₃ obtained using ethanol demonstrates the maximum sensory response to hydrogen.