Modern Physics Letters B

In this work, the extended Jacobi elliptic function expansion approach is used to analyze a generalized $(3+1)$-dimensional Gross–Pitaevskii equation with distributed time-dependent coefficients because of its use in the Bose–Einstein condensation. The Gross–Pitaevskii equation plays a significant role in Bose–Einstein condensation, where it characterizes the dynamics of the condensate wave function. By using this approach with a homogeneous balance principle, the spatiotemporal soliton solutions and exact extended traveling-wave solutions of governing equation have been successfully obtained. A few double periodic, trigonometric and hyperbolic function solutions from the Jacobi elliptic function solutions have been found under specific constraints on a parameter. It is obvious that the proposed approach is the most straightforward, efficient and useful way to handle numerous nonlinear models that arise in applied physics and mathematics in order to generate various exact solutions. A case with variable gain, constant diffraction and parabolic potential strength has been considered in this study to derive exact solutions. Numerous novel varieties of traveling-wave solutions have been revealed in this work, including the double periodic singular, the periodic singular, the dark singular, the dark kink singular, the periodic solitary singular and the singular soliton solutions and these newly obtained results differ from those previously investigated for this governing equation. In addition to addressing a scientific explanation of the analytical work, the results have been graphically presented by 3D plots and contour plots for some suitable parameter values to understand the physical meaning of the derived solutions. Due to their applicability to a variety of quantum systems, the acquired solutions are of considerable importance.

In this paper, we conducted comprehensive analysis of the selective adsorption of CO₂ by carbon and silicon prismanes along with metal ions. The results of calculations from B3LYP/6-31G(d,p) and M06-2X/6-31G(d,p) levels of theory show that Be${}^{2+}$, Mg${}^{2+}$, Ca${}^{2+}$ and Li${}^{+}$, Na${}^{+}$, K${}^{+}$ ions are bounded strongly enough to prismanes. The Be${}^{2+}$ ion binds more strongly to the C₈ H₈ cubane with binding energy 9.66eV compared to Li${}^{+}$, Na${}^{+}$, K${}^{+}$, Mg${}^{2+}$ and Ca${}^{2+}$ ions having binding energies 1.26, 0.63, 0.51, 4.60 and 3.36eV, respectively. Similar results were obtained for larger prismanes C${}_{10}$H${}_{10}$ and C${}_{12}$H${}_{12}$. Instead of binding energy, we determine the adsorption of gases on metal-ion prismane complex along with effect of temperature on different gas adsorption shows that C₈H₈_Mg${}^{2+}$ and C₈H₈_Be${}^{2+}$ are active adsorbents at temperatures above room temperature. It is also observed that in comparison to N₂ and CH₄, CO₂ interacts more strongly with all prismanes decorated with metal ions. These non-covalent interaction plots are used to study the prismane and metal-ion interaction. Comparable study of silicon prismanes with M06 2X/6-31G (d, p) basis set, in terms of binding energy, adsorption of gases on prismane along with temperature effect, also possesses similar selectivity to CO₂ molecule with even higher adsorption energies. Thus, beryllium-decorated prismanes can be considered as promising adsorbents of carbon dioxide with good selectivity and high adsorption energy.

This research paper examines the Darcy–Forchheimer flow of second-grade hybrid nanofluid with thermophoretic particle deposition on a solar collector plate in a porous media. This study performs an extensive exploration of entropy generation. Solar collector plates play a crucial role in energy storage in solar power plants. They help to store and regulate energy at extreme temperatures. This work analyzes the performance of a solar collector plate when the conventional fluid of Ethylene Glycol (EG) is reciprocated by nanoparticles of zirconium dioxide and copper. The ramifications of Magntohydrodynamic (MHD) and Cattaneo–Christov heat and mass flux are also investigated. The expressions of mass and energy are generated by using the Cattaneo–Christov model of heat and mass flux. The Homotopy analysis method (HAM) is utilized to achieve the results of differential equations against various dimensionless parameters. The fluctuating behavior of velocity, concentration and temperature profiles is discussed graphically in this paper. Furthermore, tables are included for the numerical values of skin friction, Sherwood number and Nusselt number for several parameters. As the value of the Darcy parameter raises, the fluid’s velocity distribution continuously reduces. The temperature distribution reduces along with the greater values of the thermal relaxation parameter. The concentration profile has shown decreasing impact due to the increasing value of the concentration relaxation parameter.

In this paper, the effects of plasmas on the S-wave resonance states in the positron-potassium system are investigated. Two different plasma conditions are considered, namely weakly coupled classical plasma (WCCP) and dense quantum plasma (DQP). The effective interaction potential in WCCP and DQP has been described by the Debye–Hückel model (static screened Coulomb potential) and a modified version of Debye–Hückel model (exponential cosine screened potential). Resonance parameters are determined by calculating the energy-density within the framework of the stabilization method. For the plasma-free case, three states, lying below the Ps$(n=2)$ threshold, are identified. The energy and the width agree well with the existing results in the literature. A detailed study is carried out to explore the changes emerging in the resonance parameters due to screening effects of WCCP and DQP. It is found that the energies of the three states are gradually pushed toward the Ps$(n=2)$ threshold due to the increasing plasma screening strength, whereas widths of the states vary differently.

A seven-port division is described via the connecting-slab-based reflective grating in this paper. The rigorous coupled wave analysis (RCWA) and simulated annealing algorithm (SAA) are chosen to analyze and optimize the performance of the grating. The total diffraction efficiency of TE and TM polarization is 96.75% and 95.53%, respectively. Besides, the target grating has good uniformity errors, which are reduced to 3.69% and 1.76% for TE and TM polarization, respectively. The modal method provides a physical explanation for the energy transformations within the target grating. Furthermore, the manufacturing tolerance is discussed for the seven-port division grating. Through analysis and discussion, various performances of the grating can be better demonstrated. Compared with most seven-port grating splitters reported previously, the grating in this paper achieves better diffraction efficiency uniformity and higher efficiency.

This paper deals with the results of simulation of extractive purification process of model diesel fuel (the mixture of n-hexane with thiophene and m-xylene) by molecular dynamics simulation using N-methylpyrrolidinium acetate ionic liquid as an extractant. The extractive purification process was simulated for several model fuel systems with different concentrations of sulfur and aromatic containing components. The ionic liquid exhibits high extractive ability, the degrees of desulfurization and dearomatization reach 85–90 and 60wt.%, respectively. The results were proved by experimental studies of a mixture by the ionic liquid. After 1h of contact of the ionic liquid and the model mixture, the degree of purification against thiophene was 94.2wt.%.

In this paper, a novel nanosensor comprising the metal–insulator–metal (MIM) plasmonics waveguide with a semi-elliptical and rectangular ring resonant cavity is designed. In near-infrared waveband, the propagation properties of electromagnetic waves in the structure are studied using the finite-difference time-domain (FDTD) method. The results show that, based on the coupling between the semi-elliptical and the rectangular ring resonant cavity, the transmission spectrum of the structure exhibits a sharp Fano resonance shape. Next, the influence of the refractive index and sensor structure parameters on performance is systematically investigated. The simulation results show that the sensor structure has the best sensitivity of 1384nm/RIU (refractive index unit), and the figure of merit (FOM) is 28.4. The simple MIM structure could be applied to sensitive plasmonic sensors.

Atomic-based field measurements have made significant progress in reproducibility, accuracy, and resolution enhancement. In this paper, the relative transition oscillator strength of excited 6P${}_{3/2}$ to nD${}_{5/2}$/nD${}_{3/2}$ can be measured more accurately by spectral results of Rydberg six-wave mixing, meanwhile accompanying measured efficiency of Rydberg electromagnetically induced transparent and fluorescence is compared. Relative transition oscillator strength is obtained and demonstrated, it is observed that relative transition oscillator strengths are independent of primary quantum n in thermal vapor. The measured results are approached with theoretical calculation which can not only extend relative transition oscillator strength of the measurement way in an atomic system, but can also demonstrate six-wave mixing as nonlinear process read information of laser excite atoms more accurately.