Poly-element equations reducible to moment problem for entire functions of class A

We consider poly-element linear functional equations in the class of analytic functions in the complex plane with cuts along certain segments of imaginary axis. The obtained results are applied for study of the Stieltjes moment problem for entire functions of exponential type in the class A.     

The Carleman kernel and its applications

We examine the properties of the Carleman kernel and present some applications to the theory of entire functions and difference operators.     

Experimental investigation of the role of the triplet pairing in the superconducting spin-valve effect

An important role of the morphology of a superconducting layer in the superconducting spin-valve effect has been established. The triplet pairing induced by the superconductor/ferromagnet proximity effect has been experimentally investigated for samples CoO_x/Py1/Cu/Py2/Cu/Pb (where Py = Ni_0.81Fe_0.19) with a smooth superconducting layer. The optimization of the parameters of this structure has demonstrated a complete switching between the normal and superconducting states with a change in the relative orientation of magnetizations of the ferromagnetic layers from the antiparallel to orthogonal orientation. A pure triplet contribution has been observed for the sample with a permalloy layer thickness at which the superconducting spin-valve effect vanishes. A direct comparison of the experimental data with the theoretical calculation of the temperature of the transition to the superconducting state has been performed for the first time.     

Experimental observation of the spin screening effect in superconductor/ferromagnet thin film heterostructures

When studying the nuclear magnetic resonance (NMR) of ⁵¹V nuclei in superconductor/ferromagnet thin film heterostructures, anomalous behavior of the NMR signal was observed. This effect was manifested as a systematic distortion of the high-field wing of the resonance line. We consider this to be the first experimental evidence for penetration of ferromagnetism into a superconductor.     

Structure of interfaces in thin-film metallic multilayer heterostructures

It is demonstrated that the structure of interfaces in thin-film metallic multilayers can be predicted from the phase diagrams of binary alloys of metals constituting the multilayers. Experimental data on the small-angle X-ray reflectivity and magnetization of the samples are used for characterizing the structure of the interfaces.     

The summarized equation for functions which are holomorphic in the exterior of a triangle

We consider the six-element summarized equation in the class of functions which are holomorphic in the exterior of a regular triangle and vanishing at infinity. We apply the method of integral equations and the theory of elliptic functions. Using the obtained results, we construct biorthogonal systems of holomorphic functions and study the problem of moments for integer functions of a finite degree.     

Molecular Dynamics Simulation of Ester‐Linked Hen Egg White Lysozyme Reveals the Effect of Missing Backbone Hydrogen Bond Donors on the Protein Structure

The three‐dimensional structure of a protein is stabilized by a number of different atomic interactions. One of these is hydrogen bonding. Its influence on the spatial structure of the hen egg white lysozyme is investigated by replacing peptide bonds (except those of the two proline residues) by ester bonds. Molecular dynamics simulations of native and ester‐linked lysozyme are compared with the native crystal structure and with NOE distance bounds derived from solution NMR experiments. The ester‐linked protein shows a slight compaction while losing its native structure. However, it does not unfold completely. The structure remains compact due to its hydrophobic core and a changed network of hydrogen bonds involving side chains.     

On the four-element equation for the functions analytic beyond a trapezoid and its applications

The four-element linear functional equation is studied in the class of functions analytic beyond an isosceles trapezoid and vanishing at infinity. Some system of entire functions is constructed of completely regular growth biorthogonal with a piecewise exponential weight to the system of powers on the coordinate axis.     

Regularization of linear difference equations with analytic coefficients and their applications

We propose a regularization method for four-element linear difference equations with analytic coefficients. We study these equations in the class of functions which are holomorphic in the complex plane with a cruciform cut and vanish at infinity. We give several examples illustrating the dependence of the solvability properties of equations on the choice of periodic coefficients. We describe various applications.