Russian Journal of Physical Chemistry B最新文献

Carbon based materials have the characteristics of light weight, adjustable dielectric and stable performance, so they have become the most concerned wave absorbing materials. In this paper, phenolic resin was prepared with sodium chloride as template, and then L-lysine as nitrogen source was used to add nitrogen into phenolic resin, and the final nitrogen doped hollow cubic carbon material was obtained by etching after carbonization. During the experiment, the material with excellent wave absorbing performance was prepared by controlling the doping amount of nitrogen element. Finally, it was found that the nitrogen-doped hollow cubic carbon wave absorbing material could obtain the best reflection loss of –50.26 dB and the maximum effective bandwidth of 4.68 GHz at the extremely low load of 1.75 wt %. The one-component wave absorbing material can have good absorbing performance under very low load, which can become the best candidate material for lightweight and efficient electromagnetic wave absorber without adding other materials, and achieve the purpose of “wide, strong, light and thin.”

With a particular focus on addressing environmental sustainability challenges, this study investigates the impact of buffer layers on the efficiency of CuGaSe₂ based solar cells using SCAPS simulation software program. The research examines how variations in absorber layer thickness, series resistance (R_S), and shunt resistance (R_Sh) affect electrical properties such as open-circuit voltage (V_OC), short-circuit current density (J_sc), and overall efficiency. Additionally, the influence of acceptor density (N_A) and donor density (N_D) on performance was analysed. The increasing the absorber layer thickness improves short-circuit current density (J_sc) by enhancing light absorption, which leads to more electron-hole pairs being generated. However, thicker layers also increase the distance charge carriers must travel, raising the likelihood of recombination, which reduces open-circuit voltage (V_oc). Additionally, thicker layers may introduce higher series resistance and non-ideal contact effects, further lowering V_oc. The optimal thickness was determined to be 0.5 µm, resulting in efficiencies of 21.09% for CdTe cells and 28.58% for CdS cells. Transitioning from CdTe to CdS buffer layers further enhances efficiency, while higher shunt resistance and donor density, alongside lower series resistance, contribute to improved performance. These results emphasize the importance of optimized CuGaSe₂-based solar cells performance parameters scuh as buffer layer thickness, acceptor defect density, donor defect density, series and shunt resistance on higher efficiency and better performance of the solar cells. The study provides a direction for more efficient renewable energy solutions which hold promise for sustainable future by reducing dependence on fossil fuels and mitigating carbon emissions.

Phosphorus-doped MnCo₂S₄ hollow spheres with a heterogeneous, nanosheet-assembled architecture were synthesized via a simple gas–liquid diffusion method under ambient conditions, in contrast to conventional hydrothermal and gas-phase phosphating techniques. Ammonia diffusion into a homogeneous manganese–cobalt sulfate solution led to the formation of well-dispersed hollow spheres with lamellar structures, promoting efficient electron transport and enhanced electrochemical activity. Phosphorus atoms partially substituted sulfur in the lattice, generating abundant vacancies that improved conductivity and charge transfer kinetics. The resulting electrode exhibited a high specific capacity of 928.2 C g^–1 at 1 A g^–1 and excellent cycling stability, retaining 93.8% of its capacity after 10 000 cycles. A hybrid supercapacitor was assembled using the phosphorus-doped MnCo₂S₄ as the cathode and activated carbon as the anode in 6 M KOH electrolyte. The device delivered a specific capacity of 225.6 C g^–1 at 1 A g^–1, retained 75.5% capacity at 30 A g^–1, and achieved a high energy density of 55.8 Wh kg^–1 with a power density up to 24453.6 W kg^–1, demonstrating excellent rate performance and long-term stability.

The current study involves the renewed biodiesel derived from non-edible as Juliflora and Candlenut oil into biodiesel using a two-stage trans esterification process. The physiochemical characteristics of biodiesels are analyzed and experiments are carried out employing a single-cylinder four-stroke diesel engine to test several biodiesel blends as B0, B20, B30 and B40 for, performance, and emission characteristics and experimental outcomes were analysed using Central composite modelling optimization. The results indicates the brake specific fuel consumption (0.285 kg/kW h) lower and the Brake thermal efficiency 31.8% higher for the 20% blended diesel. These values are comparable to diesel, with variations of 3.7 and 3.2% respectively. During the experiment, the emission parameters of HC, CO, and smoke were 17.67, 8.2, and 9.45% respectively, lower for CJ20 blend than diesel. Nevertheless, NO_x emission is 4.2% higher than base fuel, while minimal difference and among the lower than other blends. Furthermore, the Central composite design was developed and find the optimal results of a CI engine achieved. Overall results confirm that 20% CJ biodiesel blended diesel is the alternate of the standard diesel.

Crystal field and zero field splitting parameters of Cr³⁺ doped titanium oxide, TiO₂ (Rutile) single crystals are calculated employing superposition model. The appropriate sites for Cr³⁺ ions in TiO₂ with distortion are taken up for calculation. Splitting parameters of zero fields in theory with local distortion match comparatively well with the values found from the experiment. The optical energy bands for Cr³⁺ in TiO₂ are estimated with the Crystal Field Analysis Program and parameters of the crystal field. The results suggest that Cr³⁺ ions substitute for one of the Ti⁴⁺ ions in TiO₂ single crystals.

Based on the architecture and coevolution of allosteric materials, a mechanical model of the erythrocyte is proposed. This model is used to explain such phenomena as erythrocyte flickering and phase transitions (morphological changes) at 49.5°C, which are not fully explained from the physical point of view. To describe the viscoelastic properties of proteins (in particular, for hemoglobin), experimental data obtained earlier are taken. The difference in viscoelastic properties between different forms of hemoglobin obtained earlier is used to describe the forces that are necessary to turn on and off the springs in the spectrin network.

This study proposes a method for using thermal explosion to coat the surfaces of diamond particles quickly. This method utilizes the high temperature generated by thermal explosion to promote the rapid sublimation and deposition of Ti powder on the surfaces of diamond particles. This study applied a mixed powder of Ti and diamond particles and conducted vacuum heat treatment. Ni–Al compacts were used for thermal explosion to promote the rapid sublimation and deposition of Ti on the surfaces of diamond particles. Results indicate that Ti rapidly evaporated and deposited on the surfaces of diamond particles after thermal explosion. A composite coating of Ti and TiC on the surfaces of diamond particles formed. The compressive fracture strength and impact toughness index of the prepared Ti–TiC coated diamond particles were 16.0% and 7.4% higher than those of the original diamond particles, respectively.

To enhance the photocatalytic performance of C₃N₄ materials, g-C₃N₄/MgO heterojunction composites were efficiently synthesized from C₃N₄ and Mg(OH)₂ through a rapid heat treatment method. The photocatalytic degradation efficacy of the catalysts was assessed using methylene blue as the target pollutant under simulated solar irradiation. The findings revealed that rapid heat treatment facilitated the oxidative and thermal exfoliation of C₃N₄ powders, which subsequently formed micron-scale agglomerates upon compositing with MgO derived from the decomposition of Mg(OH)₂. The resulting C₃N₄/MgO composites greatly broadened the spectrum of visible light utilization, thereby enhancing photocatalytic performance. Notably, the g-C₃N₄/10% MgO composites exhibited the highest activity, achieving a remarkable 99.2% degradation rate of a methylene blue solution at a concentration of 10 mg/L within 45 min of simulated solar exposure.

Surface tension (ST), as a thermophysical property, has many applications in industry. Linear gradient theory (GT) is widely used to predict ST. Based on GT and the equation of state of cubic plus association (CPA), a method for calculating the ST of refrigerant mixtures is proposed in this work. Also, a new relationship has been considered for the influence parameter (IP), which is a function of the bulk and vapor phase densities, and it has a variable exponent (n). At first, the unknown coefficients ((A) and (B)) of the IP were calculated for pure refrigerants, then the binary interaction parameter (left( {{{l}_{{ij}}}} right)) was calculated for binary refrigerant mixtures to optimize the proposed model. Finally, the ST of eight binary refrigerants was obtained for different concentrations, and the calculations were repeated for five different powers of the IP. In our calculations, we considered both zero and nonzero binary interaction parameters. The results from this model show that the calculated ST is in good agreement with the experimental values. The best result is related to the binary R32+R134a considering the power of –2.5 in the proposed equation of the IP and proposing the nonzero binary interaction parameter (AAD ~ 1%)

This study investigates the enhancement of a vapour compression refrigeration system using Al₂O₃/TiO₂ composite nanolubricants with R600a refrigerant. The main objective is the experiments were performed by varying the nanolubricants concentrations and to find out the optimal concentration. Al₂O₃/TiO₂ blended nano lubricants were used to produce a greater cooling effect of 200 W along with a 30% increase by employing the ANFIS approach, which is superior to results from experiments. The approach of ANFIS was used to obtain the minimum energy utilization of 95 W. The results indicates that, the improved COP of 3.2 with a 28% higher than standard refrigerant. In comparison to experimental results, the usage of Al₂O₃/TiO₂ composite Nano lubricants resulted in an increase of COP at an optimal level, cooling effect, and a 25% reduction in compressor work to decrease energy consumption when utilizing the ANFIS prediction technique. By dispersing 0.4 g/L in R600a leads in better results in comparison with the system without nano lubricants and other nano lubricants concentrations.