250 Results Found

The exit wave is the state of a uniform plane incident electron wave exiting immediately after passing through a specimen and before the atomic-resolution transmission electron microscopy (ARTEM) image is modified by the aberration of the optical sys...

RNAs play crucial roles in various essential biological functions, including catalysis and gene regulation. Despite the widespread use of coarse-grained (CG) models/simulations to study RNA 3D structures and dynamics, their direct application is chal...

The sparse decomposition based on matching pursuit is an adaptive sparse expression method for signals. This paper proposes an idea concerning a composite dictionary multi-atom matching decomposition and reconstruction algorithm, and the introduction...

In the direction of arrival (DOA) estimation problem, when a low-bit analog to digital converter (ADC) is used, the estimation performance severely deteriorates. In this paper, the DOA estimation problem is considered in a low-cost direction finding...

Coarse-grained models have provided researchers with greatly improved computational efficiency in modeling structures and dynamics of biomacromolecules, but, to be practically useful, they need fast and accurate conversion methods back to the all-ato...

This paper proposes a fast direction of arrival (DOA) estimation method based on positive incremental modified Cholesky decomposition atomic norm minimization (PI-CANM) for augmented coprime array sensors. The approach incorporates coprime sampling o...

Precipitation is one of the most important influences on microstructural evolution during thermomechanical processing (TMCP) of micro-alloyed steels. Due to precipitation, pinning of prior austenite grain (PAG) boundaries can occur. To understand the...

Multi-camera Visual Simultaneous Localization and Mapping (V-SLAM) increases spatial coverage through multi-view image streams, improving localization accuracy and reducing data acquisition time. Despite its speed and generally robustness, V-SLAM oft...

Embedding energetically stable single metal atoms in the surface of Pt nanocatalysts exposed to varied temperature (T) and hydrogen pressure (P) could open up new possibilities in selective and dynamical engineering of alloyed Pt catalysts, particula...

An underdetermined direction of arrival (DOA) estimation method of wideband linear frequency modulated (LFM) signals is proposed without grid mismatch. According to the concentration property of LFM signal in the fractional Fourier (FRF) domain, the...

LuIII, a protoparvovirus pathogenic to rodents, replicates in human mitotic cells, making it applicable for use to kill cancer cells. This virus group includes H-1 parvovirus (H-1PV) and minute virus of mice (MVM). However, LuIII displays enhanced on...

Dissolution of iron oxides in water plays a critical role in corrosion, mineral cycling, and surface reactivity; yet, the atomic-scale mechanisms governing Fe release remain poorly understood. Here, we employ ab initio molecular dynamics and well-tem...

Nano-structuring of the surface caused by adsorption of molecules or atoms and by the reaction of surface atoms with adsorbed species are reviewed from a chemistry viewpoint. Self-assembly of adsorbed species is markedly influenced by weak mutual int...

It was demonstrated by ab initio calculations that energy optimization in the reconstruction of semiconductor surfaces is controlled by the global charge balance. The charge control was discovered during simulations of the influence of heavy doping i...

The signal reconstruction quality has become a critical factor in compressed sensing at present. This paper proposes a matching pursuit algorithm for backtracking regularization based on energy sorting. This algorithm uses energy sorting for secondar...

Cerussite is an essential lead oxide mineral with increasing economic importance as lead sulfide resources deplete. This study utilizes density functional theory (DFT) to investigate the structural and electronic properties of the sulfurized cerussit...

In the existing stochastic gradient matching pursuit algorithm, the preliminary atomic set includes atoms that do not fully match the original signal. This weakens the reconstruction capability and increases the computational complexity. To solve the...

Largish molecules on metal surfaces may act as not only the building blocks of 2D self-assemblies, but also as the template to reshape the metal surfaces. Here, we report the molecular adsorption-induced formation of the periodic nanostripe arrays of...

Adsorption complexes of germanium on the reconstructed Si(001)(4 × 2) surface have been simulated by the Si₉₆Ge₂Н₈₄ cluster. For Ge atoms located on the surface layer, DFT calculations (B3LYP/6-31G**) of their 3d semicore-level energies have shown a...

In view of the fact that most of the traditional algorithms for reconstructing underwater acoustic signals from low-dimensional compressed data are based on known sparsity, a sparsity adaptive and variable step-size matching pursuit (SAVSMP) algorith...

Segregation of foreign atoms on a solid substrate in a liquid metal modifies the geometry and chemistry of the substrate surface and, correspondingly, its potency to nucleate a solid metal. We here investigate the effects of the segregation of alkali...

In order to significantly reduce the computing time while, at the same time, keeping the accuracy and precision when determining the local values of the density and effective atomic number necessary for identifying various organic material, including...

Single particle cryo-electron microscopy (cryo-EM) has emerged as the prevailing method for near-atomic structure determination, shedding light on the important molecular mechanisms of biological macromolecules. However, the inherent dynamics and str...

This paper presents a new image focusing algorithm for sparsity-driven radar imaging of rotating targets. In the general formulation of off-grid scatterers, the sparse reconstruction algorithms may result in blurred and low-contrast images due to dic...

The cellular functions are executed by biological macromolecular complexes in nonequilibrium dynamic processes, which exhibit a vast diversity of conformational states. Solving the conformational continuum of important biomolecular complexes at the a...

In this paper, we present the design of a Teaching—Learning Sequence (TLS) based on storytelling. The TLS has a twofold goal: to address students’ misconceptions about atomic models and to promote students’ development of modeling s...

The NIFS (National Institute for Fusion Science) Atom and Molecular Database, which has been available online since 1997, is a numerical atomic and molecular database of collision processes that is important for fusion research. This database provide...

The effect of graphene (GR) on Ni surface relaxation and reconstruction in three different substrate orientations, {111}, {001}, and {011}, at two different temperatures, 300 K and 400 K, was studied using molecular dynamics simulation. The change in...

A successful application of a hot dip coating process that coats aluminum (Al) on aluminum nitride (AlN) ceramics, revealed that Al had a perfect wettability to the ceramics under specific circumstances, which was different from previous reports. In...

In this paper, we investigate the embryonic stage of oxidation of an epi Ge(001)-2 × 1 by atomic oxygen and molecular O₂ via synchrotron radiation photoemission. The topmost buckled surface with the up- and down-dimer atoms, and the first subsu...

Grain boundary (GB) segregation is an important phenomenon that affects many physical properties, as well as microstructure of polycrystals. The segregation of solute atoms on GBs and its effect on GB structure in Al were investigated using two appro...

The process of reconstruction of attosecond beating by interference of two-photon transitions (RABBITT) reveals the target atom electronic structure when one of the transitions proceeds from below the ionization threshold. Such an under-threshold RAB...

Exploring the properties of magnetic metal on the semiconductor surface is of great significance for the application of magnetic recording materials. Herein, DFT calculations are carried out to explore the properties of the iron–silicon interfa...

There is a growing trend towards the development of high resolution and multiplexing metasurface holograms. In this paper, we propose the reconstruction of polarization multiplexing terahertz (THz) holographic images based on transmissive metasurface...

This paper presents a new method for a composite dictionary matching pursuit algorithm, which is applied to vibration sensor signal feature extraction and fault diagnosis of a gearbox. Three advantages are highlighted in the new method. First, the co...

In the dual-polarized radar system, the horizontally and vertically polarized signals can be exploited to improve the direction of arrival (DOA) estimation performance. In this paper, the DOA estimation problem is considered in the dual-polarized rad...

We show, in a formal way, how a class of complex quasiprobability distribution functions may be introduced by using the fractional Fourier transform. This leads to the Fresnel transform of a characteristic function instead of the usual Fourier transf...

A sparse dictionary reconstruction algorithm based on grid selection is introduced to solve the grid mismatch when using the sparse recovery space time adaptive processing (SR-STAP) algorithm. First, the atom most closely related to clutter is select...

How in situ structural reconstructions affect the hydrogen evolution reaction (HER) activity of small Pd clusters is a long-standing problem in the field of heterogeneous catalysis. Herein, we reveal the structural evolution of Pd_n (n = 6, 19, 44) cl...

Magnetic Resonance (MR) Imaging is a diagnostic technique that produces noisy images, which must be filtered before processing to prevent diagnostic errors. However, filtering the noise while keeping fine details is a difficult task. This paper prese...

Although the Al₂Fe phase has similar decagonal-like atomic arrangements as that of the orthorhombic Al₅Fe₂ phase, no evidence for intergrowth samples of Al₂Fe and Al₅Fe₂ has been reported. In the present work, the co-existence of Al₂Fe and Al₅Fe₂ pha...

Three-axis atomic magnetometers have great advantages for interpreting information conveyed by magnetic fields. Here, we demonstrate a compact construction of a three-axis vector atomic magnetometer. The magnetometer is operated with a single laser b...

We discuss an extension of the Single-Active-Electron (SAE) approximation in atoms by allowing the model potential to depend on the angular-momentum quantum number ℓ. We refer to this extension as the ℓ-SAE approximation. The main ideas b...

Increased data acquisition by uncalibrated, heterogeneous digital sensor systems such as smartphones present new challenges. Binary metrics are proposed for the quantification of cyber-physical signal characteristics and features, and a standardized...

Atomic-scale strain is the basis of a material’s macroscopic deformation behavior. The current measure of atomic-scale strain in the form of the Green–Lagrange tensor loses its physical meaning beyond the yield point, as atomic neighborho...

This paper presents an image reconstruction method to monitor the temperature distribution of electric generator stators. The main objective is to identify insulation failures that may arise as hotspots in the structure. The method is based on temper...

We describe a combination of all-atom simulations with CABS, a well-established coarse-grained protein modeling tool, into a single multiscale protocol. The simulation method has been tested on the C-terminal beta hairpin of protein G, a model syste...

The Au–TiO₂ interface plays a critical role in heterogeneous catalysis and nanostructure synthesis relevant to renewable energy applications. Using Au-seeded TiO₂ nanowires as the model system, we observe that, in addition to the commonly repor...

Millimeter-wave automotive radar has become an essential tool for autonomous driving, providing reliable sensing capabilities under various environmental conditions. To reduce hardware size and cost, sparse arrays are widely employed in automotive ra...

Real-time observation of three-dimensional (3D) information has great significance in nanotechnology. However, normal nanometer scale observation techniques, including transmission electron microscopy (TEM), and scanning probe microscopy (SPM), have...