Journal of Micromechanics and Molecular Physics

Through the reconstructed kernel particle method (RKPM), the dynamic buckling characteristics of submarine pressure hull under hydrostatic pressure and impact load is investigated in this study. First, a large deformation buckling calculation model for stiffened shell structures was established using RKPM and elastic–plastic constitutive models. To study the influence of load asymmetry on the buckling strength of the structure and provide fundamental technical support for submarine structural design, the dynamic buckling phenomenon of the structure was studied under three conditions: hydrostatic pressure acting alone, hydrostatic pressure and impact load acting simultaneously, and hydrostatic pressure and uniformly distributed impact load acting simultaneously. The starting time of buckling was used as the criterion for determining the critical load of dynamic buckling. The results indicate that under the combined action of static and dynamic loads, asymmetric dynamic loads can seriously affect the buckling strength of the structure.

In the framework of teleparallel tachyonic model, we explore the stability of the generalized thermodynamical law and equilibrium case at Hubble horizon together with Bekenstein entropy at present as well as past epoch for flat Friedmann–Lemaître–Robertson–Walker metric. For this purpose, we take three distinct models of Hubble parameter in terms of redshift. Also, we choose power-law correction terms and specific coupling of scalar field and take observational values from $\mathrm{\text{CC}}+H_0$ dataset and compare results of all different models.

Mathematical Chemistry is concerned with the use of mathematics to solve problems in Chemistry. In Chemistry, the molecules are frequently shown as graphs with vertices denoting atoms and edges denoting bonds, respectively. Atom valences and bond multiplicities are represented by vertex degrees and edge multiplicities, respectively. The vertices in a graph are said to be close by if an edge connects them. Alkanes are a class of compounds whose physical characteristics are modelled using the chemical graph theory. The melting and boiling points of the molecules are modelled using topological indices based on the graphical structure of the alkanes. A mesh network is a local area network, in which the infrastructure nodes (i.e., bridges, switches and other infrastructure devices) connect directly, dynamically and non-hierarchically to as many other nodes as possible and cooperate with one another to efficiently route data. In this paper, the distinct degrees of triangular mesh network, enhanced mesh network, rhenium tri-oxide lattice network and star of silicate network are list with edge partitions technique. We determine the first and second Zagreb index, the modified second Zagreb index, the symmetric division index, the harmonic index and the inverse sum index. We characterise detailed proofs of these indices for each triangular network. Furthermore, their graphical representation and comparison between the certain topological indices is presented in Sec. 6. These indices are highly accurate in the study of QSPRs and QSARs because they have strong correlation with the acentric factor and entropy.

Density functional theory (DFT) provides a powerful tool for investigating the effects of halogen (F, Cl and Br) substitution on the electronic and structural properties of fluorene. The B3LYP/6-31G (d,p) protocol is a commonly used method in DFT calculations for the optimisation of molecular structures and the calculation of various molecular properties by Gaussian 09 W program. In the case of the fluorene molecule with halogen substitutions, (TD–DFT) calculations can be used to predict its UV–Vis spectrum. The B3LYP density functional model with a 6-31G(d,p) basis set is a common choice for performing (TD–DFT) calculations on molecules. The results showed a decrease in gap energies when electron-withdrawing groups were present in the molecule. A decrease in the gap energy indicates that the molecule is less stable and more reactive.

In this study, the mechanical properties of a Ni₃Al matrix composite reinforced with single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) were investigated using atomistic modeling. The analysis focused on the behavior of the composite under uniaxial tensile strain across a range of temperatures (100–900K). The results demonstrated that the incorporation of any type of carbon nanotubes (CNTs) significantly enhanced Young’s modulus, yield strength, and tensile strength of the Ni₃Al matrix. Notably, the reinforcement with MWCNTs resulted in superior mechanical properties compared to SWCNTs. Additionally, an increase in temperature led to a reduction in Young’s modulus for all composite samples. Among the tested configurations, the composite reinforced with MWCNTs exhibited the highest tensile modulus and yield strength, outperforming both the SWCNT-reinforced composite and the unreinforced Ni₃Al crystal. These findings underscore the potential of MWCNTs as effective reinforcements in improving the mechanical performance of Ni₃Al-based composites, especially at elevated temperatures.