Search results for "orbit"
showing 10 items of 1104 documents
On lower-bound estimates of the Lyapunov dimension and topological entropy for the Rossler systems
2019
In this paper, on the example of the Rössler systems, the application of the Pyragas time-delay feedback control technique for verification of Eden’s conjecture on the maximum of local Lyapunov dimension, and for the estimation of the topological entropy is demonstrated. To this end, numerical experiments on computation of finite-time local Lyapunov dimensions and finite-time topological entropy on a Rössler attractor and embedded unstable periodic orbits are performed. The problem of reliable numerical computation of the mentioned dimension-like characteristics along the trajectories over large time intervals is discussed. peerReviewed
Homoclinic Solutions of Nonlinear Laplacian Difference Equations Without Ambrosetti-Rabinowitz Condition
2021
The aim of this paper is to establish the existence of at least two non-zero homoclinic solutions for a nonlinear Laplacian difference equation without using Ambrosetti-Rabinowitz type-conditions. The main tools are mountain pass theorem and Palais-Smale compactness condition involving suitable functionals.
640-Slice CT Measurement of Superior Orbital Fissure as Gateway for Light into the Brain: Statistical Evaluation of Area and Distance.
2016
Objective Our aim was to provide normative data concerning superior orbital fissure area (SOFA), ocular skin and the substantia nigra (D-SS) and orbital fissure and the substantia nigra (D-SOF-S) distances by CT scan in adult Caucasian population. Methods The area of the superior orbital fissure (SOF), the distance between the ocular skin and the substantia nigra and the distance between the superior orbital fissure and the substantia nigra using CT and 3D-CT images. Results Normative data stratified for age and gender were obtained. The data here reported show that some degree of variability in SOFA, D-SS and D-SOF-S measurements can be observed healthy Caucasian subjects. Gender stratifie…
Large two-dimensional electronic systems: Self-consistent energies and densities at low cost
2013
We derive a self-consistent local variant of the Thomas-Fermi approximation for (quasi-) two-dimensional (2D) systems by localizing the Hartree term. The scheme results in an explicit orbital-free representation of the electron density and energy in terms of the external potential, the number of electrons, and the chemical potential determined upon normalization. We test the method over a variety 2D nanostructures by comparing to the Kohn-Sham 2D local-density approximation (LDA) calculations up to 600 electrons. Accurate results are obtained in view of the negligible computational cost. We also assess a local upper bound for the Hartree energy. Peer reviewed
Asymptotic normalization coefficients and continuum coupling in mirror nuclei
2012
Background: An asymptotic normalization coefficient (ANC) characterizes the asymptotic form of a one-nucleon overlap integral required for description of nucleon-removal reactions. Purpose: We investigate the impact of the particle continuum on proton and neutron ANCs for mirror systems from $p$- and $sd$-shell regions. Method: We use the real-energy and complex-energy continuum shell model approaches. Results: We studied the general structure of the single-particle ANCs as a function of the binding energy and orbital angular momentum. We computed ANCs in mirror nuclei for different physical situations, including capture reactions to weakly-bound and unbound states. Conclusions: We demonstr…
Paleoclimatic and Paleoceanographic reconstruction of the Pleistocene-Holocene through the study of planktonic foraminifera of two sedimentary cores …
2017
Charge radii, moments, and masses of mercury isotopes across the N=126 shell closure
2021
Combining laser spectroscopy in a Versatile Arc Discharge and Laser Ion Source, with Penning-trap mass spectrometry at the CERN-ISOLDE facility, this work reports on mean-square charge radii of neutron-rich mercury isotopes across the $N = 126$ shell closure, the electromagnetic moments of $^{207}$Hg and more precise mass values of $^{206-208}$Hg. The odd-even staggering (OES) of the mean square charge radii and the kink at $N = 126$ are analyzed within the framework of covariant density functional theory (CDFT), with comparisons between different functionals to investigate the dependence of the results on the underlying single-particle structure. The observed features are defined predomina…
Optical properties of Cr3+ and Ni2+ ions in MgO, LiNbO3 and LMA
1995
Abstract The electronic structures of Co2+ and Ni2+ ions are obtained by the molecular orbital LCGTO-LSD method. Electrostatic matrix calculations are performed for d3 and d8 configurations. Theoretical optical data are discussed in function of the impurity site location in the crystal cell.
Dissociation mechanisms of cluster ions resolved using ab-initio molecular orbital calculations
2007
We have examined the cluster-size effect on fragments in the collision-induced dissociation (CID) of small boron clusters (B + n , n ≤ 8) by means of ab-initio molecular orbital (MO) calculation, for conditions representative of low-Z cationic clusters in plasma. Single cations B + (leaving B 0 n-1 ) are predominantly fragmented from small clusters B + n (n < 5) by low-energy collisions (<10 eV) with Xe atoms. With increasing the size n, beyond n = 5, B + n-1 (leaving B°) clusters are observed preferentially. This alternating trend in experiment has not been quantitatively explained by previous ab-initio MO calculations. We used a density functional method called B3LYP and basis functions 6…
Exchange-coupled Fe-X-Fe model compounds for certain iron proteins
1988
X-ray structure studies, Mossbauer experiments and magnetic susceptibility measurements were used in connection with molecular orbital calculations to monitor structurally induced changes of electronic and magnetic properties in exchangecoupled [Fe2S2 (SR)4]2- and [Fe2OCl6]2- anions.