New insights on the factors affecting the heterogeneous kinetics of bulk Fe2O3 on the Earth: A molecular dynamic simulation

The influence of shape and matrix size on the mechanical properties of the 2D epoxy thin film by Monte Carlo simulation method

In this paper, we studied the effect of the 2D epoxy thin films’ shape with equilateral triangle and square structures, and matrix size Lx × Ly of (10 × 9), (20 × 19), (30 × 29), and (40 × 39) with equilateral triangle structure and (10 × 10), (20 × 20), (30 × 30), and (40 × 40) with the square structure on their mechanical properties [such as strain (ɛ), stress (σ), Young stress (E), and shear strain (G)] by using the Monte Carlo simulation method. The results show that when the shape of the 2D epoxy thin film is changed from an equilateral triangle structure to a square structure, the values of σ, E, and G decreased sharply. In addition, when the matrix size is increased from (10 × 9) to (20 × 19), (30 × 29), and (40 × 39) with an equilateral triangle structure and from (10 × 10) to (20 × 20), (30 × 30), and (40 × 40) with a square structure, σ slightly increased, but E and G decreased slightly. These results prove that the influence of structure shape on the mechanical properties of the 2D epoxy thin film is very large. The strain stress on the epoxy 2D thin film with an equilateral triangle structure and with a matrix size of (30 × 29) has a value of σ = 63.3 MPa. This result is consistent with the experimental result that σ of bulk epoxy has the maximum value of σmax = 64.76 MPa. The results are the basis for experimental research in future studies on practical applications of epoxy-thin films. In these cases, when thin films with equilateral triangle structures are used in biomedical fields, high stresses are required (such as replacement material for adaxial onion epidermis and fibrin and collagen with low stress).

A New Study on the Structure, and Phase Transition Temperature of Bulk Silicate Materials by Simulation Method of Molecular Dynamics

In this paper, the structure and phase transition temperature of bulk silicate materials are studied by the simulation method (SM) of molecular dynamics (MD). In this research, all samples are prepared on the same nanoscale material model with the atomic number of 3000 atoms, for which the SM of MD is performed with Beest-Kramer-van Santen and van Santen pair interaction potentials under cyclic boundary conditions. The obtained results show that both the model size (l) and the total energy of the system (Etot) increase slowly in the low temperature (T) region (negative T values) at pressure (P), P = 0 GPa. However, the increase of l determines the Etot value with very large values in the high T region. It is found that l decreases greatly in the high T region with increasing P, and vice versa. In addition, when P increases, the decrease in the Etot value is small in the low T region, but large in the high T region. As a consequence, a change appears in the lengths of the Si-Si, Si-O, and O-O bonds, which are very large in the high T and high P regions, but insignificant in the low T and low P regions. Furthermore, the structural unit number of SiO7 appears at T > 2974 K in the high P region. The obtained results will serve as the basis for future experimental studies to exploit the stored energy used in semiconductor devices.