Russian Journal of Physical Chemistry B最新文献

A hybrid alloy of [Li-ion/boron(B), aluminum(Al), gallium (Ga)] battery is figured out by a simulated anode of germanium-silicon oxide (GeOSiO) and tin-silicon oxide (SnOSiO) nanoclusters. (GeOSiO) and (SnOSiO) nanoclusters have been designed and charchterized as the electrodes for hybrid Li-ion batteries (LIBs) due to forming [LiB(GeOSiO)], [LiAl(GeOSiO)], [LiGa(GeOSiO)], [LiB(SnOSiO)], [LiAl(SnOSiO)], and [LiGa(SnOSiO)] nanoclusters. In this work, the metallliod/metal of third group elements have been studied in hybrid LiB-, LiAl-, LiGa-ion batteries through using computational approaches due to density state analysis of charge density differences (CDD), total density of state (TDOS), electron localization function (ELF). Higher Ge/Sn to Si content can increase battery capacity for energy storage compared to net Li-ion batteries and might improve the rate performances by enhancing electrical conductivity. Besides, (GeOSiO) and (SnOSiO) anode materials may advance cycling consistency by excluding electrode decline and augments the capacity owing to higher surface capacitive impacts.

Using SnSO₄ and NaOH powder as reactants, we efficiently synthesized Sn₃(OH)₂OSO₄ photocatalysts via a precipitation reaction. Subsequently, by adjusting the heat treatment temperature, a series of samples were prepared to optimize their photocatalytic performance. The results indicate that the as-synthesized Sn₃(OH)₂OSO₄ material typically exhibits an ellipsoidal flower-like structure with particle sizes ranging from 5 to 15 µm. During the heat treatment of the Sn₃(OH)₂OSO₄ samples, it was observed that as the temperature increased, the Sn₃(OH)₂OSO₄ gradually decomposed, forming a composite of Sn₂OSO₄ and SnO. ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS) revealed that compared to the untreated Sn₃(OH)₂OSO₄ sample, the synthesized samples demonstrated superior light absorption in both the partial ultraviolet range (310–400 nm) and the visible light region. Moreover, as the heat treatment temperature increased, the light absorption capacity of the samples gradually improved, while their bandgap values correspondingly decreased. Photocatalytic degradation experiments further confirmed that appropriately increasing the heat treatment temperature enhanced the samples’ degradation efficiency. Under ultraviolet light, visible light, and simulated sunlight irradiation, the best-performing sample (heat-treated at 350°C) was able to completely or nearly completely degrade methyl orange within 45, 60, and 30 min, respectively.

Magnetorheological elastomers are smart materials that have recently attracted considerable interest. Their physical properties vary significantly in presence of a magnetic field. This study examines these properties and proposes a new model for the design of systems using magnetorheological elastomers. First, a fabrication process for these materials is presented, and then their dynamic properties are studied under different magnetic field intensities and different filling rates by ferromagnetic particles. To control and ensure uniaxial orientation of the ferromagnetic particles, the magnetorheological elastomer samples at different filling rates were cured under a magnetic field via coils. A variation in shear moduli was observed with increasing volume fraction of ferromagnetic particles and applied magnetic field. Using these experimental results, the appropriate volume fraction of ferromagnetic particles, applied magnetic field, and design procedure can be proposed as guidelines for optimizing the development of future magnetorheological elastomers.

A software package is developed in the Python programming language for the conceptual design of a process flow diagram for producing chitosan aerogel particles. The software package covers the calculation of the entire production chain, including the stages of solution preparation, gelation, solvent replacement in the gel pores, and supercritical drying. The structure of the package includes a mathematical model of flow hydrodynamics in a receiving tank, a model of diffusion mass transfer in the porous structure of chitosan gel particles, a material balance calculation, an equipment parameter calculation unit, and a technical and economic assessment subsystem. Using the software package, the user can determine the optimal parameters for the process of producing chitosan aerogel particles and create a preliminary process flow diagram for the production process adapted to the specified constraints. The software package is designed to scale the technology for producing chitosan aerogel particles and calculate the cost of production at various productivity levels.

The article presents the analysis of numerical simulation results for the parameters of air shock waves formed during detonation of a hydrogen–air mixture volume limited by a movable shell. The calculations were performed using the GasDynamicsTool package in a two-dimensional formulation. The propagation of detonation and shock waves in a channel of constant cross-section was considered. The volume with the reacting mixture is separated from the environment (air) by a movable thin-walled membrane (shell). When exposed to a detonation wave, the membrane starts moving and an air shock wave is formed in front of it. The flow features caused by the reflection of the detonation wave on the membrane were revealed. It was found that with a relatively small membrane mass, the effect of the explosion can be enhanced. Data were obtained on the dynamics of membrane acceleration depending on its mass. The results of numerical calculations substantiate the possibility of experimental modeling of explosions of fuel-air clouds with a free boundary with an appropriate choice of material and thickness of the shell limiting the combustible mixture.

Rapid ignition of fuel mixtures is crucial for efficient operation of airbreathing engines. This study investigates the ignition delay times of ethylene-air, ethylene-oxygen, and Propulsion grade Kerosene-air mixtures under various conditions relevant to airbreathing propulsion systems. Experiments were conducted using a shock tube to measure ignition delay times over a wide range of temperatures (800–1700 K) and equivalence ratios (0.5–1.5). The effects of temperature, pressure, and fuel type on ignition delay were examined. Results demonstrate that ignition delay decreases monotonically with increasing temperature and pressure for all fuel mixtures. A comparison between ethylene and Propulsion Grade Kerosene revealed that the latter exhibits sufficiently short ignition delay times for practical applications in airbreathing engines. Additionally, kinetic modeling was performed using various reaction mechanisms to validate the experimental results, ensuring consistency and reliability of the findings across the range of tested parameters.

In this study, we evaluated the structural and magnetic properties of a group of five-membered single-ring heterocyclic compounds containing N⁺–O^– bonds. We used quantitative criteria to describe their aromaticity, including magnetic parameters like nuclear independent chemical shift, structural harmonic oscillator for aromaticity, and aromatic stability energy, as well as magnetic susceptibility and the HOMO–LUMO gap. For this study, all compounds were optimized using the B3LYP method and G**+311-6 basis set, and various aromaticity parameters were calculated at this level. It was found that the presence of the N‑oxide group decreased the diatropic flow within the ring, leading to a reduction in the compounds' aromaticity. Specifically, the N⁺–O^– dipole enhanced electron polarization within the structure, resulting in decreased electron density within the ring. Then, with the assistance of molecular orbital analysis, the impact of the N-oxide group on the reactivity of these compounds was explored. It was noted that the N-oxide group alters the distribution of electron density on the carbon atoms of the ring, consequently enhancing the reactivity of C–H bonds with higher electron density to facilitate direct arylation reactions. Increasing the number of nitrogen atoms in the ring also increases the energy and electron density of these compounds.

This investigation aims to investigate scandium-doped gallium nitride (Sc-doped GaN) alloys (x = 0.25, 0.50, 0.75) in hexagonal structure and (GaN)₁/(ScN)₂/(GaN)₂/(ScN)₂ superlattices for high-efficiency optoelectronic solar cells using multiscale DFT and SCAPS-1D simulations. Our computational analysis confirms the energetic stability of all investigated compounds. Electronic structure calculations reveal semiconducting behavior with tunable bandgaps ranging from 1.7 to 2.7 eV, positioning these materials as promising candidates for optoelectronic applications. Optical characterization demonstrates significant absorption across the visible to ultraviolet spectrum, making these compounds particularly suitable for photovoltaic applications. Device simulations of Sc-doped GaN-based solar cells yielded remarkable performance metrics, achieving a maximum power conversion efficiency of 14.5%. Notably, the devices exhibited an exceptional fill factor of 86%, indicating highly efficient carrier extraction and transport properties. These findings establish Sc-doped GaN and its related superlattice structures as viable materials for next-generation high-efficiency solar cell technologies, combining optimal electronic band structure with superior optical absorption characteristics.

Different types of fuel cells are studied in order to clarify the best application for each type. The current paper includes a comparative research of basic design, working principle, applications, advantages and disadvantages of various technologies available for fuel cells, experimentally. In this work, the overall diffusion layer thickness was evaluated based on the measured catalyst layer thickness and plain carbon cloth technical data. The voltages/current characteristics were first acquired for the lowest concentration around 0.1 to 0.2 M for DMFC, PEMFC, and DFAFC. In the case of DFAFC, the increase in FA concentration from 0.1, 0.2, 1 M enhanced the DFAFC power densities. In the case of DFAFC 2.0 M, the increase in the concentration caused an increasing in power densities, possibly related to the enhanced crossover of the fuel. The AFC exhibited almost the highest operating efficiency compared with DMFC and DFAFC. There for the performance sequencing of these fuel cells based on their power densities can be resulted as follows AFC > DFAFC > DMFC > PEMFC. It was also discussed that although all types of fuel cells operate on similar basis; Alkaline is the most efficient (75%), followed by Direct formic acid (DFAFC) (50%) and Direct Methanol (DMFC) (40%) in terms of power efficiency.

Experimental and theoretical analysis of long-lived luminous Formation—Ball lightning (BL) creation in experiments and nature has been made. Experiments with plasma jet from the standard erosive plasma generator were carried out. Studies a possibility of creating analogues of BL in laboratory conditions at plasma jet influence on metals: aluminum, iron, copper, solder in order to find out. Energy input from the plasma generator was 1200–1500 J. The current maximum I, was 72 A, plasma pulse time was 7–25 ms. Spherical luminous formations with dimensions up to 1.5 cm and a lifetime of up to 3–7 s were obtained. They have a shell and a cavity filled by a vapor. By a way of motion, they are similar to natural BL. The similarity of these objects to natural BL is discussed. Theory of BL based on these experiments is presented. It describes BL as a formation with a quasi- solid cover and an internal core filled by a hot gas. Electric charges from the linear lightning makes the BL highly charged object.