BaBiOa is the parent compound of the new class of high Tc superconductors that contain no copper. By partially replacing Ba with K (or Bi with Pb) B a!_xK xBi0 3 becomes superconducting in a small range of x. The undoped material is a semiconductor in which the perovskite structure is unstable with re­ spect to a breathing-like distortion (Fig. 1) of the oxy­ gen octahedron (Bi disproportionate...

This study evaluates the performance of two fundamentally different approaches to achieve sub-pixel precision of normalised crosscorrelation when measuring surface displacements on mass movements from repeat optical images. In the first approach, image intensities are interpolated to a desired sub-pixel resolution using a bi-cubic interpolation scheme prior to the actual displacement matching. ...

This paper presents a practical representation containing a parameter of rational cubic conic sections and research’s deeply the inner properties. Firstly, the parameter how to affect the control points, inner weights and shoulder point is discussed. Secondly, the inner relation between the parameter and the weights of the nonstandard-form quadratic rational conic sections is analyzed in detail...

Abstract We introduce neural networks (NNs) to compute numerical Ricci-flat Calabi–Yau (CY) metrics for complete intersection and Kreuzer–Skarke (KS) CY manifolds at any point in Kähler complex structure moduli space, the package cymetric which provides computation realizations of these techniques. In particular, we develop computationally realize methods point-sampling on manifolds. The traini...

The longitudinal optical conductivity is the most important property for graphene-baseddevices. So investigating this property for spatially separated few-layer graphene systems analytically and numerically is the main purpose of our study. Each layer can be mono- or bi-layer graphene. The density-density correlation function has been screened by the dielectric function using the random p...

A geometrically exact membrane formulation is presented that is based on curvilinear coordinates and isogeometric finite elements, and is suitable for both solid and liquid membranes. The curvilinear coordinate system is used to describe both the theory and the finite element equations of the membrane. In the latter case this avoids the use of local cartesian coordinates at the element level. C...

The algorithm we develop outputs the order and the structure, including generators, of the -Sylow subgroup of the group of rational points of an elliptic curve defined over a finite field. To do this, we do not assume any knowledge of the group order. We are able to choose points in such a way that a linear number of successive -divisions leads to generators of the subgroup under consideration....

Simulations of the Transverse Susceptibility (TS) signal for single-domain and for systems of ferromagnetic particles are presented. When calculating the TS for single domains, details are provided concerning the uniaxial and cubic anisotropies. For the uniaxial single-domain particles a 2D critical approach can be used. The TS for cubic anisotropy is essentially a 3D problem that was solved wi...

This paper addresses weak approximation for rationally connected varieties defined over the function field of a curve, especially at places of bad reduction. Our approach entails analyzing the rational connectivity of the smooth locus of singular reductions of the variety. As an application, we prove weak approximation for cubic surfaces with square-free discriminant.

Approximating complex curves with simple parametric curves is widely used in CAGD, CG, and CNC. This paper presents an algorithm to compute a certified approximation to a given parametric space curve with cubic B-spline curves. By certified, we mean that the approximation can approximate the given curve to any given precision and preserve the geometric features of the given curve such as the to...