Predictions of Lattice Parameters in NiTi High-Entropy Shape-Memory Alloys Using Different Machine Learning Models.

This work applied three machine learning (ML) models-linear regression (LR), random forest (RF), and support vector regression (SVR)-to predict the lattice parameters of the monoclinic B19' phase in two distinct training datasets: previously published ZrO-based shape-memory ceramics (SMCs) and NiTi-based high-entropy shape-memory alloys (HESMAs). Our findings showed that LR provided the most accurate predictions for a, a, b, and c in NiTi-based HESMAs, while RF excelled in computing β for both datasets. SVR disclosed the largest deviation between the predicted and actual values of lattice parameters for both training datasets.

Using U-Net convolutional neural network to model pixel-based electrostatic potential distributions in GaN power MIS-HEMTs.

This study demonstrates a novel use of the U-Net convolutional neural network (CNN) for modeling pixel-based electrostatic potential distributions in GaN metal-insulator-semiconductor high-electron mobility transistors (MIS-HEMTs) with various gate and source field plate designs and drain voltages. The pixel-based images of the potential distribution are successfully modeled from the developed U-Net CNN with an error of less than 1% error relative to a TCAD simulated reference of a 500-V electrostatic potential distribution in the AlGaN/GaN interface. Furthermore, the modeling time of potential distributions by U-Net takes about 80 ms.

Device simulations with A U-Net model predicting physical quantities in two-dimensional landscapes.

Although Technology Computer-Aided Design (TCAD) simulation has paved a successful and efficient way to significantly reduce the cost of experiments under the device design, it still encounters many challenges as the semiconductor industry goes through rapid development in recent years, i.e. Complex 3D device structures, power devices.

The mechanism underlying silicon oxide based resistive random-access memory (ReRAM).

In this work, we have inspected the theoretical resistive switching properties of two ReRAM models based on heterojunction structures of Cu/SiO nanoparticles (NPs)/Si and Si/SiO NPs/Si, in which dielectric layers of the silica nanoparticles present dislocations at bicrystal interfaces. To validate the theoretical model, a charge storage device with the structure Cu/SiO /Si was fabricated and its ReRAM properties were studied. Our examinations on the electrical, thermal and structural aspects of resistive switching uncovered the switching behavior relies upon the material properties and electrical characteristics of the switching layers, as well as the metal electrodes and the interfacial structure of grains within the dielectric materials.

Carrier Mobility Calculation for Monolayer Black Phosphorous.

Monolayer black phosphorous (BP) is a commonly used semiconducting two-dimensional material, thanks to its unique electronic properties of an atomically thin two-dimensional layered structure and its ability to be applied in a novel nanoscale metal-oxide-semiconductor field-effect device. In this paper, we focus on a new compact band structure model and apply it to electron mobility calculations for monolayer BP. We propose a new compact band model based on an effective mass approximation considering a second-order non-parabolic correction to calculate the band structure, density of states, velocity squared, and other physical quantities of monolayer BP.

Probing C84-embedded Si Substrate Using Scanning Probe Microscopy and Molecular Dynamics.

This paper reports an array-designed C84-embedded Si substrate fabricated using a controlled self-assembly method in an ultra-high vacuum chamber. The characteristics of the C84-embedded Si surface, such as atomic resolution topography, local electronic density of states, band gap energy, field emission properties, nanomechanical stiffness, and surface magnetism, were examined using a variety of surface analysis techniques under ultra, high vacuum (UHV) conditions as well as in an atmospheric system. Experimental results demonstrate the high uniformity of the C84-embedded Si surface fabricated using a controlled self-assembly nanotechnology mechanism, represents an important development in the application of field emission display (FED), optoelectronic device fabrication, MEMS cutting tools, and in efforts to find a suitable replacement for carbide semiconductors.

Microyielding of core-shell crystal dendrites in a bulk-metallic-glass matrix composite.

In-situ synchrotron x-ray experiments have been used to follow the evolution of the diffraction peaks for crystalline dendrites embedded in a bulk metallic glass matrix subjected to a compressive loading-unloading cycle. We observe irreversible diffraction-peak splitting even though the load does not go beyond half of the bulk yield strength. The chemical analysis coupled with the transmission electron microscopy mapping suggests that the observed peak splitting originates from the chemical heterogeneity between the core (major peak) and the stiffer shell (minor peak) of the dendrites.

Investigation into the mechanical properties of single-walled carbon nanotube heterojunctions.

The mechanical properties of finite-length (6,0)/(8,0) single-walled carbon nanotube (SWCNT) heterojunctions with respect to different kinds of connection segments, either coaxial or bias, are investigated using molecular dynamics simulation calculations. It is found that the resulting significant deformation of structure and significant drop of stress under yielding strain is due to the strain localization. Moreover, the deformation is occurred below the heptagon ring in the thinner segment of the heterojunctions under tension at different temperatures, whereas under compression it occurs on the heptagon ring.

Binding hot-spots in an antibody-ssDNA interface: a molecular dynamics study.

Simulating antigen-antibody interactions is essential for elucidating antigen-antibody mechanics. Proteins interactions are vital for elucidating antibody-ssDNA associations in immunology. Therefore, this study investigated the dissociation of the human systemic lupus erythematosus antibody-ssDNA complex structure.

Target molecular simulations of RecA family protein filaments.

Modeling of the RadA family mechanism is crucial to understanding the DNA SOS repair process. In a 2007 report, the archaeal RadA proteins function as rotary motors (linker region: I71-K88) such as shown in Figure 1. Molecular simulations approaches help to shed further light onto this phenomenon.

Structure-dependent mechanical properties of ultrathin zinc oxide nanowires.

Mechanical properties of ultrathin zinc oxide (ZnO) nanowires of about 0.7-1.1 nm width and in the unbuckled wurtzite (WZ) phase have been carried out by molecular dynamics simulation.

Adsorption and dissociation of the O2 on W(111) surface: a density functional theory study.

The adsorption and dissociation of O2 molecules on W(111) surface have been studied at the density functional theory (DFT) level in conjunction with the projector augmented wave (PAW) method. All passable dissociation reaction paths of O2 molecule on W(111) surface are considered. The nudged elastic band (NEB) method is applied to locate transition states, and minimum energy pathways (MEP).

The interfacial behavior of water/PMMA thin film under normal compression.

Molecular dynamics simulation (MD) has been used to investigate the structure property of water/PMMA interface under compression and compression release. A virtual repulsive wall was employed to generate a normal compression strain on the simulation model, leading a compressive system. In order to understand the difference of interfacial phenomenon between the system under strain and under release, the hydrogen bond and density distributions of water and PMMA along the normal direction are calculated.

The scratch behaviors of copper bi-layers by a diamond tip: a molecular statics study.

The scratch deformation behaviors of two bicrystal coppers (Cu(100)/Cu(110) and Cu(110)/Cu(100)) during the nanoscratching process were explored and compared with their single crystal ingredients by the molecular statics simulations. The effects of lattice configuration and scratch depth were investigated in this study. The results showed that the motion of dislocations was blocked in the bicrystal interface until the dislocations accumulated enough energy to move.

Hydrogen-bond structure at the interfaces between water/poly(methyl methacrylate), water/poly(methacrylic acid), and water/poly(2-aminoethylmethacrylamide).

The molecular dynamics approach was employed to study the structural characteristics at the interface of water/poly(methyl methacrylate) (PMMA), water/poly(methacrylic acid) (PMAA), and poly(2-aminoethylmethacrylamide) (PAEMA). It is found that the water on the PMAA surface shows a significant increase in the density at the interface, with a greater number of water molecules permeating into the bulk of the substrate region. The structure of hydrogen bonds of water and the radial distribution function for given polar atoms in the polymer substrate are calculated.

Modeling of the polyethylene and poly(L-lactide) triblock copolymer: a dissipative particle dynamics study.

Dissipative particle dynamics (DPD), a mesoscopic simulation approach, has been used to investigate the effect of the arrangement of the microstructure and the effect of the volume fraction on the structural properties of the immiscible polyethylene (PE)/poly(L-lactide) (PLLA) polymer in the triblock copolymer system. In this work, the interaction parameter in DPD simulation, related to the Flory-Huggins interaction parameter chi, is estimated by the calculation of mixing energy for each pair of components in molecular dynamics simulation. The immiscibility property of PE and PLLA polymers induces phase separation and exhibits different architectures at different volume fractions.

Penetration and adsorption of a water droplet causing local deformation of the poly(methyl methacrylate) surface.

A molecular dynamics approach has been employed to study the wetting behavior of poly(methyl methacrylate) (PMMA). The flexible and rigid models of PMMA substrate are compared. The results verify that the rigid model is not suitable to act as the PMMA substrate in simulation because it prevents the diffusion of PMMA molecules, which affects the penetration behavior of water molecules.

Dynamical property of water droplets of different sizes adsorbed onto a poly(methyl methacrylate) surface.

A molecular dynamics approach has been employed to study the dynamical behavior of a water droplet adsorbed on a poly(methyl methacrylate) (PMMA) surface. Several sizes of water droplets are considered in order to understand the size influence of the droplet on the dynamical properties of water molecules on the PMMA substrate. The local density profile of water molecules in the droplet upon impact with the PMMA surface is calculated, and the result shows an increase in water penetration with a decrease in the size of the droplet.

Chain-length effects on conformations of methyl methacrylate-oligomer thin films on an Au(111) substrate.

Molecular dynamics simulations were employed to investigate chain-length effects on conformations of methyl methacrylate (MMA)-oligomer thin films on an Au(111) substrate. Some observations were obtained from the present research. For short chain films, there is a sharp peak in the density profile of the MMA monomers for the adsorption region and the thin films exhibit a flattened conformation in the adsorption and the surface regions.

Temperature effect on the dynamic behavior of tricarboxylic acid derivatives in two-dimensional network structures.

The temperature effect on the adsorption behavior and the dynamic behavior of TCMB 2D network structure on the Au(111) substrate has been investigated. From the calculation of the adsorbed energy between the molecule and the Au(111) substrate, it can be found that there are significant changes in adsorbed energy as the temperature increase; moreover, different migration features are appeared at different specific temperature, owing to the deformation of the 2D network structure changed. The mean square displacement (MSD) and diffusion coefficient are calculated to study the migration property and dynamical behavior of 2D TCMB networks at specific temperatures.

Combined molecular dynamics and dissipative particle dynamics to study of the microstructure of poly(L-lactide)/polyethylene blends.

Different type of polymers miscibility has been induced great interest, owing to its relevance to the understanding of processing and performance properties of blends containing different type of polymers. In this article, we investigate the microstructure of poly(L-lactide) (PLLA)/polyethylene (PE) blends. The simulation method is adopted molecular dynamics and dissipative particle dynamics.

A molecular dynamics study of nanoindentation on a methyl methacrylate ultrathin film on a Au(111) substrate: interface and thickness effects.

The molecular dynamics simulation model of nanoindentation is proposed in order to study the mechanical and structural deformation properties of an ultrathin MMA (methyl methacrylate) film on a Au(111) surface. First, the significant differences in the structural arrangement of MMA thin films with different thicknesses are observed. Two layers are apparent in the thinnest MMA thin film next to the Au(111) surface, while three layer structures are apparent in the thicker film.

Adsorption of water molecules inside a Au nanotube: a molecular dynamics study.

A molecular dynamics simulation of water molecules through a Au nanotube with a diameter of 20 A at bulk densities 0.8, 1, and 1.2 gcm(3) has been carried out.

Adsorption mechanism of water molecules surrounding Au nanoparticles of different sizes.

Molecular dynamic simulation is used to investigate the adsorption mechanism of water molecules surrounding Au nanoparticles with different sizes. Our results show that the adsorption mechanism of the water molecules in the first water shell will be influenced by the size of the Au nanoparticle. For the larger Au nanoparticles, the hydrogen bonding of water molecules adsorbed on the surface of the Au nanoparticles are arranged in a two-dimensional structure, while those adsorbed on the edge of the surface of the Au nanoparticles are arranged in a three-dimensional structure.

Modeling of polyethylene and poly (L-lactide) polymer blends and diblock copolymer: chain length and volume fraction effects on structural arrangement.

Dissipative particle dynamics (DPD), a mesoscopic simulation approach, has been used to investigate the chain length effect on the structural property of the immiscible polyethylene (PE)/poly(L-lactide) (PLLA) polymer in a polymer blend and in a system with their diblock copolymer. In this work, the interaction parameter in DPD simulation, related to the Flory-Huggins interaction parameter chi, is estimated by the calculation of mixing energy for each pair of components in molecular dynamics simulation. The immiscibility property of PE and PLLA polymers induces the phase separation and exhibits different architectures at different volume fractions.