Preparation of undoped and indium doped ZnO thin films by pulsed laser deposition method

An original modification of the standard Pulse Laser Deposition (PLD) method for preparing both undoped and indium doped zinc oxide (ZnO:In) thin films at low substrate temperature is proposed. This preparation method does not demand any further post‐deposition annealing treatment of the grown films. The developed method allows to grow thin films at low substrate temperature that prevents them from the considerable loss of their intrinsic electrical and optical properties. The influence of deposition parameters on the electrical and optical parameters of the undoped and the indium doped ZnO thin films is also analysed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

The effect of photoactivated transformations of Ag+ and Ag0 in silica fillers on their biocidal activity

Research on Chemical Intermediates - Ag and AgCu containing powdered silica fillers of polymers for medical applications have been synthesized using mechanochemical activation with a low content of...     

The Efficacy of Aprotinin Combinations with Selected Antiviral Drugs in Mouse Models of Influenza Pneumonia and Coronavirus Infection Caused by SARS-CoV-2

The efficacy of aprotinin combinations with selected antiviral-drugs treatment of influenza virus and coronavirus (SARS-CoV-2) infection was studied in mice models of influenza pneumonia and COVID-19. The high efficacy of the combinations in reducing virus titer in lungs and body weight loss and in increasing the survival rate were demonstrated. This preclinical study can be considered a confirmatory step before introducing the combinations into clinical assessment.     

Nucleophilic substitution of hydrogen–the Boger reaction sequence as an approach towards 8-(pyridin-2-yl)coumarins

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Higher borides and oxygen-enriched Mg–B–O inclusions as possible pinning centers in nanostructural magnesium diboride and the influence of additives on their formation

The study of high pressure (2 GPa) synthesized MgB₂-based materials allows us to conclude that higher borides (with near MgB₁₂ stoichiometry) and oxygen-enriched Mg–B–O inclusions can be pinning centers in nanostructural magnesium diboride matrix (with average grain sizes of 15–37 nm). It has been established that additions of Ti or SiC as well as manufacturing temperature can affect the size, amount and distribution of these inclusions in the material structure and thus, influence critical current density. The superconducting behavior of materials with near MgB₁₂ stoichiometry of matrix is discussed.     

Estimates of Riesz Constants for the Dirac System with an Integrable Potential

We consider the Dirac operator on the interval [0, π] with an integrable potential P = (p_ij (x)) _i,j=1 ² and strongly regular boundary conditions U. It is well known that for any integrable potential P the system {y_n}_n∈Z of root functions of the strongly regular operator L_P,U is a Riesz basis in the space H = L₂[0, π] × L₂[0, π]. We obtain estimates, uniform on every compact set of potentials, of the Riesz constants ||T||||T^?1||, where T is the operator of transition to an orthonormal basis.     

Inverse problems for Sturm—Liouville operators with potentials in Sobolev spaces: Uniform stability

Two inverse problems for the Sturm-Liouville operator Ly = s-y″ + q(x)y on the interval [0, fy] are studied. For θ ⩾ 0, there is a mapping F:W ₂^θ → l _B ^θ, F(σ) = {s _k }₁^∞, related to the first of these problems, where W ₂^∞ = W ₂^∞[0, π] is the Sobolev space, σ = ∫ q is a primitive of the potential q, and l _B ^θ is a specially constructed finite-dimensional extension of the weighted space l ₂^θ, where we place the regularized spectral data s = {s _k }₁^∞ in the problem of reconstruction from two spectra. The main result is uniform lower and upper bounds for ∥σ - σ₁∥_θ via the l _B ^θ-norm ∥s − s₁∥_θ of the difference of regularized spectral data. A similar result is obtained for the second inverse problem, that is, the problem of reconstructing the potential from the spectral function of the operator L generated by the Dirichlet boundary conditions. The result is new even for the classical case q ∈ L ₂, which corresponds to θ = 1.     

Preparation and Properties of Frost-Resistant Materials Based on Compounds of Oligoether Urethane Epoxides and Diglycidyl Urethane

A procedure was suggested for preparing epoxy ether urethane oligomers via intermediate oligodiisocyanates with increased content of the starting 2,4-toluene diisocyanate. The procedure allows preparation of epoxy-containing oligomers with appreciable fraction of low-molecular-mass diglycidyl urethane. The presence of diglycidyl urethane in the binder enhances not only the adhesion but also the strength of the cured material without significantly affecting the glass transition point of the binder. Elastic materials prepared by curing the compounds studied with cylcoaliphatic amines exhibit enhanced levels of strength and low-temperature elasticity.