Structure and magnetic properties of icosahedral PdAg (x = 0-13) clusters.

In this article, we present a modified Velocity-Verlet algorithm that makes cluster system converge rapidly and accurately. By combining it with molecular dynamics simulations, we develop an effective global sampling method for extracting isomers of bimetallic clusters. Using this method, we obtain the isomers of icosahedral PdAg (x = 0-13).

Nonsequential double ionization with mid-infrared laser fields.

Using a full-dimensional Monte Carlo classical ensemble method, we present a theoretical study of atomic nonsequential double ionization (NSDI) with mid-infrared laser fields, and compare with results from near-infrared laser fields. Unlike single-electron strong-field processes, double ionization shows complex and unexpected interplays between the returning electron and its parent ion core. As a result of these interplays, NSDI for mid-IR fields is dominated by second-returning electron trajectories, instead of first-returning trajectories for near-IR fields.

Local Magnetoelectric Effect in La-Doped BiFeO3 Multiferroic Thin Films Revealed by Magnetic-Field-Assisted Scanning Probe Microscopy.

Multiferroic La-doped BiFeO3 thin films have been prepared by a sol-gel plus spin-coating process, and the local magnetoelectric coupling effect has been investigated by the magnetic-field-assisted scanning probe microscopy connected with a ferroelectric analyzer. The local ferroelectric polarization response to external magnetic fields is observed and a so-called optimized magnetic field of ~40 Oe is obtained, at which the ferroelectric polarization reaches the maximum. Moreover, we carry out the magnetic-field-dependent surface conductivity measurements and illustrate the origin of local magnetoresistance in the La-doped BiFeO3 thin films, which is closely related to the local ferroelectric polarization response to external magnetic fields.

Electric field control of the magnetic anisotropy energy of double-vacancy graphene decorated by iridium atoms.

To solve the fundamental dilemma in data storage applications, it is crucial to manipulate the magnetic anisotropy energy (MAE). Herein, using first-principles calculations, we predict that the system of double-vacancy graphene decorated by iridium atoms possesses high stability, giant MAE, perpendicular-anisotropy and long-range ferromagnetic coupling. More importantly, the amplitude of MAE can be manipulated by electric fields.

Polarization-dependent interfacial coupling modulation of ferroelectric photovoltaic effect in PZT-ZnO heterostructures.

Recently, ferroelectric perovskite oxides have drawn much attention due to potential applications in the field of solar energy conversion. However, the power conversion efficiency of ferroelectric photovoltaic effect currently reported is far below the expectable value. One of the crucial problems lies in the two back-to-back Schottky barriers, which are formed at the ferroelectric-electrode interfaces and blocking most of photo-generated carriers to reach the outside circuit.

High-temperature quantum anomalous Hall effect in honeycomb bilayer consisting of Au atoms and single-vacancy graphene.

The quantum anomalous Hall effect (QAHE) is predicted to be realized at high temperature in a honeycomb bilayer consisting of Au atoms and single-vacancy graphene (Au2-SVG) based on the first-principles calculations. We demonstrate that the ferromagnetic state in the Au2-SVG can be maintained up to 380 K. The combination of spatial inversion symmetry and the strong SOC introduced by the Au atoms causes a topologically nontrivial band gap as large as 36 meV and a QAHE state with Chern number C = -2.

Pd nanoparticle-modified electrodes for nonenzymatic hydrogen peroxide detection.

A hydrogen peroxide (H2O2) sensor based on Pd nanoparticles (NPs) and glassy carbon electrodes (GCEs) is fabricated. Pd NPs are deposited on GCEs by using a gas phase cluster beam deposition technique. The NP-deposited electrodes show enhanced electrocatalytic activity in reduction of H2O2.

Reversible switching of magnetic states by electric fields in nitrogenized-divacancies graphene decorated by tungsten atoms.

Magnetic graphene-based materials have shown great potential for developing high-performance electronic devices at sub-nanometer such as spintronic data storage units. However, a significant reduction of power consumption and great improvement of structural stability are needed before they can be used for actual applications. Based on the first-principles calculations, here we demonstrate that the interaction between tungsten atoms and nitrogenized-divacancies (NDVs) in the hybrid W@NDV-graphene can lead to high stability and large magnetic anisotropy energy (MAE).

First-principles prediction of magnetic superatoms in 4d-transition-metal-doped magnesium clusters.

We theoretically predict magnetic superatoms in the 4d-transition-metal-doped Mg8 clusters using a spin-polarized density functional theory method. We demonstrate that TcMg8 is highly energetically stable in both structure and magnetic states, and identify it as a magnetic superatom with a magnetic moment as large as 5 μB. The magnetic TcMg8 with 23 valence electrons has a configuration of 1S(2)1P(6)1D(10) closed shell and 2S(1)2D(4) open shell, complying with Hund's rule similar to the single atom.

Local electrical conduction in polycrystalline La-doped BiFeO₃ thin films.

Local electrical conduction behaviors of polycrystalline La-doped BiFeO3 thin films have been investigated by combining conductive atomic force microscopy and piezoelectric force microscopy. Nanoscale current measurements were performed as a function of bias voltage for different crystal grains. Completely distinct conducting processes and resistive switching effects were observed in the grain boundary and grain interior.

Comparative pharmacokinetics of chlorogenic acid after oral administration in rats.

The present study was aimed at the comparison of the pharmacokinetics of pure chlorogenic acid and extract of Thunb. The animals were allocated to two groups, and were administered chlorogenic acid or extract of Thunb. at a dose of 50.

First principles studies on the interaction of O2 with X@Al12 (X = Al-, P+, C, Si) clusters.

The interaction of O(2) with the doped icosahedral X@Al(12) (X = Al(-), P(+), C, Si) clusters with 40 valence electrons were investigated using density functional theory methods. A different behavior exhibited between Al(13)(-) and X@Al(12) (X = P(+), C, Si) when they interact with O(2). The dissociation of O(2) on Al(13)(-) is strongly dependent on spin state of oxygen molecule.

Structures and magnetic properties of Si(n)Mn (n = 1-15) clusters.

The structure, electronic, magnetic properties of Si(n)Mn clusters up to n=15 are systematically investigated using the density functional theory within the generalized gradient approximation. In the most stable configurations of Si(n)Mn clusters, the equilibrium site of Mn atom gradually moves from convex, to a surface, and to a concave site as the number of Si atoms varying from 1 to 15. Starting from n=11, the Mn atom completely falls into the center of the Si outer frame, forming Mn-encapsulated Si cages.

[Tissue distribution and excretion of 5-fluorouracil from indomethacin 5-fluorouracil-1-ylmethylester in rats].

To study the tissue distribution and excretion of indomethacin 5-fluorouracil-1-ylmethyl ester (IFM) metabolite 5-fluorouracil in rats, an accurate and specific high performance liquid chromatography method for quantifying IFM in rat plasma and tissues was developed. Biological samples were prepared by liquid-liquid extraction and separated on a Diamonsil C18 column (250 mm x 4.6 mm ID, 5 microm).

Relativistic computational investigation: the geometries and electronic properties of TaSi(n)+ (n = 1-13, 16) clusters.

The equilibrium geometries, stabilities, and electronic properties of the TaSi(n)+ (n = 1-13, 16) clusters are investigated systematically by using the relativistic density functional method with generalized gradient approximation. The small-sized TaSi(n)+ clusters with slight geometrical adjustments basically keep the frameworks that are analogous to the neutrals while the medium-sized charged clusters significantly deform the neutral geometries, which are confirmed by the calculated AIP and VIP values. Furthermore, the optimized geometries of the charged clusters agree with the experimental results of Hiura and co-workers (Hiura, H.

Structural and electronic properties of TaSi(n) (n=1-13) clusters: a relativistic density functional investigation.

The TaSi(n) (n=1-13) clusters with doublet, quartet, and sextet spin configurations have been systematically investigated by a relativistic density functional theory with the generalized gradient approximation available in Amsterdam density functional program. The total bonding energies, equilibrium geometries, Mulliken populations as well as Hirshfeld charges of TaSi(n) (n=1-13) clusters are calculated and presented. The emphasis on the stabilities and electronic properties is discussed.

Chaotic behavior of channeling particles.

Channeling describes the collimated motion of energetic charged particles along the lattice plane or axis in a crystal. The energetic particles are steered through the channels formed by strings of atomic constituents in the lattice. In the case of planar channeling, the motion of a charged particle between the atomic planes can be periodic or quasiperiodic, such as a simple oscillatory motion in the transverse direction.