Molecular Dynamics Simulations of Structural Changes for a Molten Ag54Cu1 Cluster during Cooling

Structural changes of an Ag54Cu1 cluster had been computationally studied by molecular dynamics approaches. Packing transition was demonstrated by analytical tools including potential energy, atomic density profiles, and shape factor as well as visually packing images. During the process of temperature decreasing, this cluster preferentially assumes icosahedral geometry. Copper atom usually has an atomic position inside a cluster. As temperature decreases, its position will change. Potential energy shows different temperature regimes in the structural transformation. Atomic density profile gives packing pattern in different region. Shape factor presents the morphology changes of this cluster.

Matter

This chapter takes a look at Razi’s atomic theory of matter: why it must be posited as an eternal principle alongside God and soul, and how bodies are made up of atoms. It is shown that Razi had a fairly detailed theory as to how atomic density explains the property of elemental bodies, as well as several arguments for the reality of void. The resulting theory is more comparable to that of the ancient atomists than to the atomism of contemporary Islamic theologians. A final section attempts to understand Razi’s writings on alchemy in the light of this atomistic physics, and suggests that alchemical transformations may be explained on his view in terms of the manipulation of atoms.

Low In-plane Atomic Density Phosphorene Anodes for Lithium-/sodium-ion Batteries

Phosphorus anode offers a high theoretical capacity for lithium-/sodium-ion batteries, but it suffers a serious expansion during charging even formed of 2D black phosphorene (α-P), which seriously affects their cycle...

Modeling Interactions between Graphene and Heterogeneous Molecules

The Lennard–Jones potential and a continuum approach can be used to successfully model interactions between various regular shaped molecules and nanostructures. For single atomic species molecules, the interaction can be approximated by assuming a uniform distribution of atoms over surfaces or volumes, which gives rise to a constant atomic density either over or throughout the molecule. However, for heterogeneous molecules, which comprise more than one type of atoms, the situation is more complicated. Thus far, two extended modeling approaches have been considered for heterogeneous molecules, namely a multi-surface semi-continuous model and a fully continuous model with average smearing of atomic contribution. In this paper, we propose yet another modeling approach using a single continuous surface, but replacing the atomic density and attractive and repulsive constants in the Lennard–Jones potential with functions, which depend on the heterogeneity across the molecules, and the new model is applied to study the adsorption of coronene onto a graphene sheet. Comparison of results is made between the new model and two other existing approaches as well as molecular dynamics simulations performed using the LAMMPS molecular dynamics simulator. We find that the new approach is superior to the other continuum models and provides excellent agreement with molecular dynamics simulations.

Editorial for Special Issue “Heavy Metals Accumulation, Toxicity, and Detoxification in Plants”

“Heavy metals” is a collective term widely applied for the group of metals and metalloids with an atomic density above 4 g/cm3 [...]

Spectroscopic investigation of non-thermal plasma generated in atmospheric pressure ‘Plasma Pencil’

Plasma generated at atmospheric pressure has widespread applications in the field of plasma medicine. In this paper, spectroscopic investigations of homemade capacitively coupled, atmospheric pressure RF plasma pencil is reported. Optical emission spectroscopy (OES) technique is employed to characterize the plasma. Variation in rotational/gas temperature [Formula: see text], [Formula: see text] atomic density, dissociation fraction [Formula: see text] and normalized intensities of [Formula: see text], [Formula: see text] and [Formula: see text] radiation is monitored as a function of discharge parameters like RF power and different gases concentration. [Formula: see text] of [Formula: see text] mixture is estimated from [Formula: see text] band head of R branch of first negative system of nitrogen [Formula: see text], [Formula: see text], [Formula: see text] using Boltzmann plot technique. Similarly, [Formula: see text] band head of second positive system (SPS) of nitrogen [Formula: see text], [Formula: see text], [Formula: see text] is also used to estimate [Formula: see text] by fitting synthetic spectra over the experimentally recorded spectrum. It is noted that [Formula: see text] increases with increase in RF power, but it decreases with increase in [Formula: see text] concentration in the mixture. [Formula: see text] atomic density and dissociation fraction [Formula: see text], estimated from [Formula: see text] line at 750 nm and [Formula: see text] line at 844 nm using actinometry technique, show increasing trend with RF power and [Formula: see text] concentration in the mixture up to 0.7% [Formula: see text] in the mixture. The normalized [Formula: see text] radiation intensities; [Formula: see text], [Formula: see text] and [Formula: see text] show the increasing trend with increase in RF power up to 0.3% [Formula: see text] concentration in the mixture.