Modern Physics Letters B最新文献

Electron transfer in the electrode–solution interface is responsible for the signal in the electrochemical sensor. However, the Electrical Double-Layer (EDL) characteristic is usually ignored in signal modeling. Here, we constructed a model based on the reaction–diffusion equation to describe the dynamics in the EDL during sensing. With this model, many common experimental phenomena, such as transient/steady-state current variation or detection nonlinearization, can be unraveled by exploring the effects of position, kinetics proportionality coefficient (k), and reaction order ($\beta$). We also put forward some suggestions to improve the stability and linear detection range for future sensor design.

This study reports both MagnetoHydroDynamics (MHD) and heat generation aspects of a water-based hybrid nanofluid flow with various shapes of the nanoparticles involving Nimonic 80A and ${\mathrm{\text{Fe}}}_3{\mathrm{\text{O}}}_4$, over a moving wedge. Similarity transformations were adapted to obtain non-dimensional equations and solved using MATLAB bvp4c code. All the results and graphs were formulated after a positive outcome of our results with that available in existing literature. Nusselt number, which signifies the heat transfer rate in a flow, increased with an increase in empirical shape factors of the nanoparticle with a contrasting decrease in the drag experienced during the flow, represented by the skin friction coefficient. The velocity profile decreased at a rate of 0.75% for $M=0.6$ to $M=0.8$ due to the augmenting Lorentz forces while it augmented by 18.9% for an augmenting velocity ratio parameter from $R=0.0$ to $R=0.5$ due to the no-slip boundary conditions. Both the Nusselt number and skin friction coefficients decreased with an increase in magnetic parameter. An increase in the nanoparticle concentration resulted in an incrementing streamline value along with increasing temperature profile due to increasing thermal conductivity of the fluid flow system. The physical significance of the study involves in its applications in nuclear, steel industries, MRI scanning for its anti-corrosive and high thermal conductivity properties.

The synthesis of TiO₂/MoO₃/Au nanocomposite has been carried out to study its photocatalysis activity. A hydrothermal technique was used to systematically incorporate titanium dioxide (TiO₂), molybdenum trioxide (MoO₃), and gold nanoparticles (Au NPs) to produce a synergistic nanostructured material. The analysis of prepared nanocomposite was performed using several characterization methods. UV-visible spectroscopy is used to examine the existence of materials and optical absorption. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were among the methods used to study the crystalline phases and surface morphologies. Methylene blue organic pollutants were used to evaluate the photocatalytic activity of the resulting TiO₂/MoO₃/Au nanocomposites under visible light irradiation. The TiO₂/MoO₃/Au composite showed significant photocatalytic performance among the three composites.

In this paper, we study the Fokas–Lenells equation, which is a derivation form of the nonlinear Schrödinger equation and can be used to describe nonlinearity in the propagation of optical pulses. To seek solutions for this nonlinearity, the Logistic method has been proposed in order to drive acceptable and understandable results regarding physical meaning. This method is defined based on the summation of an ordinary differential equation. Moreover, for further study, the Bernoulli $(F^{\prime }/F)$-expansion method is used by considering hypothetical solutions as a function of the Bernoulli equation. Subsequently, solutions of the Fokas–Lenells equation are successfully acquired, displaying efficient results in hyperbolic, trigonometric, and exponential equations. The importance of these results appears in the definition of the wave function under the consideration of the appropriate coefficients. Hence, computer simulation is used for better understanding of the generated results. The dynamic behaviors of these solutions are demonstrated in 3D graphs, contour maps, and line plots, under applying various parameters, solutions of the waves show different soliton behaviors, including bright-dark, bright, and breather solitons. The results indicate that the exerted methods are novel, reliable, and effective approaches which can be employed in a wide range of nonlinear differential equations. These methods and their begotten results are far from the complexities of mathematical structures and therefore go beyond previous efforts in the literature.

In this study, hydroxyapatite (HA) was extracted from biological waste. HA was modified by N,N-diglycidylaniline (NDY) and DOPO-HQ to obtain the flame retardant which was added to epoxy resin (EP) to prepare the composite. The flame retardancy of the composites was measured by the horizontal and vertical combustion tester (UL-94) and the limiting oxygen index (LOI), the thermal property was carried out by the thermogravimetric analyzer (TGA), and the surface morphology was observed by the field emission scanning electron microscope (SEM). The UL-94 grade of pure EP is a fail grade, and the LOI value was 22%. After adding HA-NDY-DOPOHQ (weight ratio 1:2:1) 40$$wt.% flame retardant, the UL-94 grade of the composites was raised to V-1, and the LOI value promoted to 28%, a total increase of 6%. Composite materials had excellent thermal stability and flame retardancy and could be used in fireproof panels for energy storage systems to prevent thermal runaway, and could also be used in building materials.

In this paper, the extended (3+1)-dimensional potential KP equation in fluid mechanics is studied through Hirota bilinear method. Many types of hybrid solutions, such as the lump–kink solution, lump-two kink solution and periodic lump solution are obtained by assuming different functions in the bilinear equation. The interaction solution between lump and triangular periodic wave is also derived by combining sine and cosine functions with quadratic functions. Dynamical structures of these exact solutions are depicted by presenting the corresponding three-dimensional, two-dimensional structures and density graphs. These diverse interaction solutions could be helpful for understanding physical phenomena in fluid mechanics.

In this study, we investigated the impact of adding Triphenylphosphine (TPP) at concentrations of 1$$wt.%, 3$$wt.%, and 5$$wt.% to an epoxy-anhydride system that displays, a degradation in mechanical properties at high temperatures. We conducted an analysis of cure behavior using differential scanning calorimetry and evaluated flexural, shear, and tensile strengths at room temperature. To assess heat resistance, CFRP specimens were exposed to 100^∘C for 1$$h, and tensile strengths were subsequently measured. The addition of 3$$wt.% TPP resulted in a 5$$min reduction in the time required to reach a 95% degree of cure, but it was observed that mechanical properties at room temperature were compromised. CFRP exposed to 100^∘C indicated that an increase in TPP content helped mitigate the degradation of mechanical properties.

I theoretically construct a kind of new angular momentum coherent states by virtue of the nonlinear Bose SU(2) generators, and investigate their nonclassicality by analyzing the sub-Poissonian distributions, photon number distributions, entanglement entropy and Wigner phase-space distributions. The results show that the new states always have the sub-Poissonian distributions for all of the photon number sum $n_a+n_b=q$ of two modes, the photon number distributions are subjected to the parameter q, and the entanglement always increases quickly and then decreases slowly with increasing $\varsigma$, and the new states for odd q possess more stronger nonclassicality than for even q.

In this paper, we examine the time-dependent two-dimensional cable equation of fractional order in terms of the Caputo fractional derivative. This cable equation plays a vital role in diverse areas of electrophysiology and modeling neuronal dynamics. This paper conveys a precise semi-analytical method called the q-homotopy analysis transform method to solve the fractional cable equation. The proposed method is based on the conjunction of the q-homotopy analysis method and Laplace transform. We explained the uniqueness of the solution produced by the suggested method with the help of Banach’s fixed-point theory. The results obtained through the considered method are in the form of a series solution, and they converge rapidly. The obtained outcomes were in good agreement with the exact solution and are discussed through the 3D plots and graphs that express the physical representation of the considered equation. It shows that the proposed technique used here is reliable, well-organized and effective in analyzing the considered non-homogeneous fractional differential equations arising in various branches of science and engineering.

Thin films of zinc oxide (ZnO) have unique properties that make them suitable for various applications. In this study, we used a spray pyrolysis process to develop undoped ZnO and ZnO doped with Sn thin films on a glass substrate. We aimed to investigate the effect of Sn concentration on the optical, nonlinear optical, and structural properties of ZnO:Sn thin films. X-ray diffraction analysis revealed that all the deposited ZnO thin films exhibit polycrystalline hexagonal structures well-oriented along the c-axis. The obtained films were transparent in the visible range, with a transmittance between 70% and 80%. The optical energy bandgap values for the films varied from 3.16 eV to 3.29 eV. We also determined the second- and third-order nonlinear susceptibilities, which decreased with increasing Sn concentration. We investigated the photocatalytic activity of the ZnO-doped Sn thin films using methylene blue dye under visible light. Sn doping enhanced the photocatalytic activity of ZnO thin films, with constant rate values of 0.00046 and 0.00074 min${}^{-1}$ for ZnO and ZnO:Sn thin films, respectively.