Compact Inverses of The Multipoint Normal Diferential Operators For First Order

In this work, firstly all normal extensions of a multipoint minimal operator generated by linear multipoint diferential-operator expression for first order in the Hilbert space of vector functions in terms of boundary values at the endpoints of the infinitely many separated subintervals are described. Finally, a compactness properties of the inverses of such extensions has been investigated.Comment: 9 page

Some Generalizations of Riesz-Fisher Theorem

In the paper are obtained the generalizations of Housdorff-Young, Riesz and Paley type theorems with respect to uniformly orthonormed system for the case of the space L(p,q) with the mixed norm

Spectrum of the Direct Sum of Operators

In this work, a connection between some spectral properties of direct sum of operators in the direct sum of Hilbert spaces and its coordinate operators has been investigated.Comment: 10 page

Influence of dispersing additive on asphaltenes aggregation in model system

The work is devoted to investigation of the dispersing additive influence on asphaltenes aggregation in the asphaltenes-toluene-heptane model system by photon correlation spectroscopy method. The experimental relationship between the onset point of asphaltenes and their concentration in toluene has been obtained. The influence of model system composition on asphaltenes aggregation has been researched. The estimation of aggregative and sedimentation stability of asphaltenes in model system and system with addition of dispersing additive has been given

Long-Term Photometric and Spectral Variations of DI Cephei

We have analyzed the photometric and spectral variations of the classical T Tauri star DI Cep for the last 50 years. Currently the star is at its faintest state and possesses an emission spectrum in the visual range. Synchronous spectroscopy and UBV R photometry show that the higher the brightness, the stronger were the intensities of hydrogen Hα, Hβ emission lines and of FeII, HeI λ5876 ˚A emissions. For the first time, we detected, with a high probability, quasi-periodic variations of the star’s brightness and of its spectrum with the period P = 2020 ± 200 days

DEFINITION of EXTENDED STRUCTURAL DEFECTS IN EPITAXIAL FILMS of ZnTeG‘GaAs GROWN by MBE

The last three decades of the development of solid state physics are characterized by the fact that the main objects of research are increasingly not massive crystals, but thin films, multilayer thin-film systems, conducting filaments and crystallites of small size. Epitaxial films are grown on a substrate of a single crystal of the same or another material. In the first case, the epitaxial layer with the correct technology becomes a natural extension of the substrate. Epitaxial film can be doped with various impurities. To introduce an alloying admixture into the epitaxial film, three methods are used. According to the first method, the necessary admixture is dissolved in the source of the semiconductor material. The second method involves the use of an alloying admixture in an elementary form and its placement in the pipe between the source of the semiconductor material and the substrate. Sometimes the alloying admixture is placed in a separate temperature zone of the working pipe. The third method is to add an alloying admixture to the volatile iodides. Interest in the study of quantum-dimensional structures based on A2B6 materials is due to the possibility of manufacturing on their basis of injection sources of coherent and incoherent radiation, as well as emitters with electronic pumping, covering almost the entire visible range. To clarify the nature of the luminescence centers responsible for the i1c band, we studied the effect on the FL spectra of the buffer ES ZnTe: (I)a thin (5-10 nm) intermediate recrystallized ZnTe layer located between the buffer layer and the substrate (100) GaAs; (ii)the thickness of the buffer layer, as well as (III) the build-up of quantum-dimensional layers CdxZn1-xTeG‘ZnTe (xq0.2-0.4). In addition, the spatial distribution (in buffer depth) of the intensity (I) and spectral position (m) of THE i1c band, as well as temperature dependences of I and m were investigated. At the same time, x-ray diffraction measurements of the swing curves were carried out to control the structural perfection of the ZnTe ES. In the exciton region of the spectrum, there are also intense band I1C hmq2.356 eV and located in close proximity to her far side strip with hmq2.352 eV (I2C) lower intensity. In the samples with quantum layers from the short-wave side of I1C, an additional band IX with hmq2.359 eV is observed. A number of characteristics of the bands in the group I1C different from the corresponding characteristics such as both free and associated excitons. Thus, the change in the technology of growing MBE epitaxial buffer layers ZnTeG‘GaAs: (1) the use of a thin, recrystallized layer ZnTe (d10 nm), as well as (2) an increase in the thickness of the buffer layer leads to an improvement in the structure of the ES, as well as an increase in the total intensity of the FL bands in the exciton spectrum and a decrease in the impurity. The paper also provides with additional information on the nature of the i1c band and the IX band found near it. The difference between the temperature and deformation dependences of the positions of these bands on the corresponding characteristics of the exciton radiation lines, as well as the increase in their intensity with a decrease in deformations made it possible to link these bands with extended defects. Based on these data, as well as the results of x-ray diffraction measurements, it is assumed that the centers responsible for the I1C band are associated with the boundaries of the subunits in the mosaic structure