Russian Journal of Physical Chemistry B最新文献

Studying the physical properties of long-lived plasma formations can help us understand the nature of electrophysical phenomena in thunder clouds, the lower ionosphere, tornadoes, volcanic activity, and the associated appearance of natural plasmoids (such as ball lightning, sprites, jets, etc.). The stimulated detonation of long-lived energy-consuming plasmoids (LEPs) obtained in a laboratory using a combined type of plasma generator consisting of an erosive plasma generator and a magnetoplasma compressor (MPC) is studied in this paper. It is found that a necessary condition for detonation is the excess of certain threshold values of pressure and temperature. The existence of a directed explosion mode is established, which is realized only at the optimal delay times (of the order of t_d ~ 2000 μs) between the beginning of a pulsed erosion discharge and the discharge of an MPC. The parameters of shock waves (SWs), as well as the optical and X-ray spectra of LEPs in the stimulated detonation mode are measured.

The formation of collision complexes, also called quasi-complexes (QCs), metastable dimers, or Feshbach resonances, is studied for CH₄–He, Ne, and Ar systems by the method of classical trajectories. The calculations use exact 3D classical Hamilton equations in the action–angle variables and nonempirical surfaces of the interaction’s potential energy. The collision parameters are selected by the Monte Carlo method. A statistical analysis of the QC parameters is performed. It is shown that QCs can be both short-lived and long-lived and are characterized by a variety of interparticle separations. Among the total number of collisions, the fraction of QCs increases rapidly with a decrease in temperature. Formulas are given that reveal the contribution of QCs to the cross sections of the rotational RT-relaxation of CH₄. It is shown that in the methane mixtures considered the RT-relaxation in QC-type collisions is much more effective than in ordinary inelastic collisions.

The contribution of disordered perturbations in density, velocity, and pressure to the pair entropy of an unstable system, which sets the direction of its evolution, is estimated. The disordered perturbations arising in the incoming flow due to an external influence are calculated by the numerical integration of regular equations of multimoment hydrodynamics supplemented with stochastic components. The distortion of the pair entropy of the system due to disordered perturbations is calculated in a problem of the flow around a stationary solid sphere. It is established that disordered perturbations of the density, velocity, and pressure do not have any noticeable effect on the parameters of the vortex street in the wake behind the sphere.

lasma-liquid interactions play a crucial role in various scientific and indusPtrial applications. Understanding the behavior and effects of plasmas interacting with liquids is essential for fields such as plasma medicine, plasma-based water treatment, plasma-assisted combustion and plasma-enhanced chemical reactions. Plasma-liquid interactions involve complex physical and chemical processes, including ionization of liquids, generation of reactive species, formation of plasma-induced waves and electric fields in the liquid and transfer of energy and momentum between plasma and liquid phases. The density of electrons and their volume fraction are fundamental factors that influence plasma-liquid interactions. These interactions are highly dependent on the temperature of the plasma, with cold plasma or nonthermal plasma being particularly relevant in ambient temperature settings. In order to study and model plasma-liquid interactions, careful attention must be paid to the presence of free or chemically bonded liquid phases in the plasma structure. Simulations of plasma-liquid interactions are challenging due to the highly nonlinear properties, coupled equations and the lack of reliable experimental benchmarks. Overall, understanding plasma-liquid interactions is vital for a wide range of scientific and industrial applications. This abstract review explores the diverse applications of plasma-liquid interactions in various fields, including nanomaterial synthesis, sterilization, disinfection and environmental remediation. The interaction between non-thermal plasma and liquid phases has led to significant advancements in nanomaterial processing, with plasma-liquid interactions offering efficient methods for nanoparticle synthesis, surface functionalization and controlled growth. In addition, plasma technology has been instrumental in sterilization and disinfection processes, providing rapid and effective means of microbial inactivation on surfaces, in water sources and in air. The review highlights the versatility of plasma systems in environmental applications, such as water treatment and soil remediation, showcasing the potential of plasma-liquid interactions for sustainable solutions. By examining the fundamental principles, applications and future perspectives of plasma-liquid systems, this review underscores the importance of plasma technology in advancing materials science, healthcare practices and environmental protection.

The problem of the heterogeneous recombination of nitrogen and oxygen atoms is considered. The processes influencing the results of measurements of the recombination probability are analyzed. This study presents the authors' data on the heterogeneous recombination of atoms in the temperature range of 300–3000 K and pressures of 0.01–50 hPa (mbar). The probabilities of the heterogeneous recombination of O and N atoms on the surface of quartz are measured using the method of resonance fluorescence spectroscopy (RFS) under strictly controlled conditions at temperatures of 300–1000 K and pressures of 0.01–10 hPa in reactors at the Institute of Biochemical Physics (IBCP). The pressure and temperature regions where recombination occurs predominantly according to the Langmuir–Hinshelwood or Rideal–Eley scheme are determined. In experiments at the VAT-104 TsAGI installation in the temperature range of 1000–3000 K and pressures of 5–50 hPa, the effective values of the rate constant of the joint heterogeneous recombination K_w of nitrogen and oxygen atoms are determined using measurements of specific heat flows. Coatings with a surface layer similar in composition to quartz and a number of high-temperature ceramics based on hafnium (zirconium) borides are studied. Studies of ceramics show that heterogeneous recombination also occurs at temperatures of 2500–3000 K. A new mechanism of the heterogeneous recombination of nitrogen and oxygen atoms is considered. Under the influence of a high-speed plasma flow, the ceramics are oxidized and a layer of hafnium (zirconium) oxide polycrystals is formed. The observed jump in temperature by ≈1000 K and heat flux up to 4–5 times is caused by the catalytic activity of the tetragonal and cubic phases of HfO₂ (ZrO₂) polycrystals. The high catalytic activity of the oxide layer is apparently explained by a new recombination mechanism related to the incorporation of nitrogen and oxygen atoms in the crystal lattice (formation of a solid solution).