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This paper investigates the analytical solutions of the autocatalytic reaction–diffusion Selkov–Schnakenberg system of coupled nonlinear PDEs mathematical perspective. This is a simple chemical reaction system that admits periodic solutions. The new families of exact solutions are derived which represent the autocatalyst and reactant of chemical concentrations. These exact solutions are obtained by using the technique namely as ϕ6-model expansion. Furthermore, the existence of these solutions is also discussed under different constraint conditions and variables of concentrations that are represented in hyperbolic, trigonometric, and rational forms. These results are new and effective in the physical phenomena of autocatalytic chemical reactions. For a better understanding of the physical interpretation of the solutions, the 3D and 2D graphs of some reported solutions are dispatched below for the different choices of parameters. Hence the physical description of our results may fruitful tool for investigating the further results for nonlinear wave problems in applied science.

In this study, solitary wave solutions for the generalized (3+1)-dimensional nonlinear wave equation (NLWE) are extracted using a new generalized exponential rational function method (GERFM). Numerous nonlinear behaviors in liquids with gas bubbles are described by this equation. The suggested method is used to derive the various kinds of new accurate soliton solutions for the equation. Also, the physical interpretations of some obtained solutions are represented. In addition, a modulational instability analysis framework is used to look at the system’s stability.

The study’s main objective is to assess a channel heat exchanger’s thermal and hydraulic characteristics in the presence of turbulent air-flow at a fixed Reynolds number. Using two distinct versions of the obstacles in terms of their shape, fixation, and arrangement, the baffles and fins are implanted inside the channel. To convert a conventional flow path into a wave-shaped one, a first model contains rectangular baffles alternately distributed throughout the channel surfaces. According to the horizontal axis of the channel, between the edges of the baffles in the first type, the second model relates to square and in-line deflectors (fins). On each of the channel’s solid bounds, the boundary criteria are specified. An k-ε turbulence model was used to build the mathematical model for flow and energy. As might be predicted, the pressure, velocity, and temperature fields exhibit the greatest fluctuations in the areas closest to the obstacles. [ABSTRACT FROM AUTHOR]

In this piece, the impact of an obstacle's upstream edge inclination in a rectangular channel is investigated. The main purpose of this study is to give a better understanding of this associated phenomenon by reflecting more accurately the different cooling techniques and to get as close as possible to real conditions of use. This study is based on the laws of conservation of mass, momentum, and energy, the equations are given in the case of the 2-D flow of an incompressible Newtonian fluid, depending on the variables primitives given below. During the study, we used the FLUENT computer code, as well as its GAMBIT mesh generator several times, which allowed us to become more familiar with numerical simulation. The purpose of our numerical research is to clarify physical phenomena that are described by theory without using more expensive experimentation. [ABSTRACT FROM AUTHOR]

Novel antitumor compounds featuring isoquinoline and indole moieties were synthesized by a silver nitrate promoted domino reaction involving intramolecular cyclization, nucleophilic addition of indole, and subsequent N-N bond cleavage. The transformation from readily available starting materials into an interesting class of indolesubstituted isoquinolines was completed under mild conditions and by simple operations in moderate to good yields. The antitumor activity of these compounds in vitro was significantly greater than that of a reference compound, 5-fluorouracil. The products might serve as new lead compounds for drugs for the treatment of cancer. [ABSTRACT FROM AUTHOR]

An unprecedented silver nitrate mediated novel transformation of aromatic hydrazones into various isoquinolines has been developed. This method involves a silver nitrate promoted cyclization of aromatic hydrazones followed by N-N bond cleavage, and has wide substrate scope under mild conditions. [ABSTRACT FROM AUTHOR]

A variational-integral perturbation method (VIPM) has been established by combining the variational perturbation with the integral perturbation. We present the results obtained by the application of VIPM to the ground and excited states associated with the Zeeman effect on a hydrogen atom. We construct correction wave functions and calculate energy corrections for the ground state and some high excited states. These values are compared with results of Smith and Jason et al.; our results are more accurate than those from Smith and Jason, especially in the 4f excited state where we find a very interesting result that when magnetic fields increase, the energy level trap appears. [ABSTRACT FROM AUTHOR]

A samarium diiodide promoted tandem β-elimination/ cross-pinacol coupling was developed. A series of novel 1-vinyl- 1,2-diols with two adjacent quaternary carbon centers were obtained in moderate to good yields. Possible reaction pathways are proposed. [ABSTRACT FROM AUTHOR]

Microcapsules containing phase change materials (microPCMs) have many potential applications because of their thermoregulation or thermosaving abilities. At the same time, it is still essential to understand the interface stability of microPCMs/polymer composites during a thermal transmission. The aim of this work was to fabricate novel microPCMs containing dodecanol by an in situ polymerization using methanol-modified melamine-formaldehyde (MMF) prepolymer as shell material and investigate the interface morphologies of microPCMs/epoxy composites treated by a simulant thermal process with a ten times repeated temperature variation. A series of microPCMs were fabricated by 1,000-3,000 r·min emulsion speed with the PCM contents of 40-70%. The average diameter, melting temperature, and encapsulation efficiency of microPCMs were 1-16 μm, 19.5 °C, and 97.4%, respectively. Tests results indicated that the properties of the microPCMs were greatly affected by core/shell ratios and emulsification stirring rates of preparation conditions. With the increasing of stirring rates, the average diameters of microPCMs were sharply decreased. The encapsulation efficiency ( E) values of microPCMs increased with the increasing of stirring rates. The contents of PCM in microcapsules ( C) and the average diameter of microPCMs both affected the interface morphologies of microPCMs/epoxy composites after the repeated thermal treatments. Microcracks and gaps occurred after a thermal treatment in the interface of microPCMs and epoxy matrix obviously. The internal stress generated by the expansion or shrinking of the microPCMs was the main factor leading to the interface morphology changes and damaged of composites. [ABSTRACT FROM AUTHOR]

Random copolyester namely, poly(ethylene terephthalate‐co‐sebacate) (PETS), with relatively lower molecular weight was first synthesized, and then it was used as a macromonomer to initiate ring‐opening polymerization of l‐lactide. 1H NMR quantified composition and structure of triblock copolyesters [poly(l‐lactic acid)‐b‐poly(ethylene terephthalate‐co‐sebacate)‐b‐poly(l‐lactic acid)] (PLLA‐PETS‐PLLA). Molecular weights of copolyesters were also estimated from NMR spectra, and confirmed by GPC. Copolyesters exhibited different solubilities according to the actual content of PLLA units in the main chain. Copolymerization effected melting behaviors significantly because of the incorporation of PETS and PLLA blocks. Crystalline morphology showed a special pattern for specimen with certain composition. It was obvious that copolyesters with more content of aromatic units of PET exhibited increased values in both of stress and modulus in tensile test. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007 [ABSTRACT FROM AUTHOR]

Phase formation and evolution of high‐impact polystyrene with poly(cis‐butadiene) rubber blends was studied. The characteristic length, L , was defined to describe the size of particles, and the graph‐estimation method was introduced to determine the width of the distribution of L. Based on the method, the distribution of L proved to be a log‐normal distribution and the distribution width of L was calculated. The phase structure was also discussed in the wave‐number space. The correlation distance, a c , was defined and computed, applying light‐scattering theory to power spectrum images obtained by 2‐dimensional Fourier transformation (2DFT). The change of a c was in accord with that of L , which meant 2DFT was valid to study the phase structure. A fractal dimension, D c , was introduced to describe the uniformity of the spatial distribution. The result showed that D c was an effective parameter to study the distribution of particles of the dispersed phase. [ABSTRACT FROM AUTHOR]

Entangled states with high-dimensional systems have been investigated widely because of its various advantages. This paper investigates the effect of the weak measurement and reversal (WMR) on the protection of the entanglement for an arbitrarily entangled qutrit–qutrit state from the amplitude-phase decoherence sources. By solving the master equation of the qutrit–qutrit system, we numerically get the maximal amount of entanglement. The numerical results show explicitly that the WMR operation indeed helps for protecting entanglement from amplitude-phase decoherence. In particular, WMR can protect entanglement more efficiently in the case of strong decay rates than those with small decay rates. These results shed new light on the protection of high-dimensional quantum entanglement in a complex quantum environment. [ABSTRACT FROM AUTHOR]