Two shapes of antenna elements have been investigated and compared to obtain phased antenna arrays with circular polarization in the far field; a feed network providing a Chebyshev distribution of current amplitudes and uniform distribution of phases has been designed for 4×4 arrays; phased arrays with modified square and circular patches have been designed and compared, providing sidelobe reduction of up to −26 dB.
Show AbstractModification of the Discrete Sources Method based on employing of “fictitious” particle is suggested and performed. This approach allows one to perform an effective numerical analysis of the scattering properties of nanodimensional substrate defects, such as shallow pits and shallow bumps. Numerical results that demonstrate the capabilities of the implemented computer module are presented.
Show AbstractReduced graphene oxide (RGO) particles were obtained from natural and artificial graphite using chemical reduction. The particles were placed on an aqueous subphase surface in a Langmuir trough from suspensions in carbon tetrachloride. Compression isotherms of layers of RGO particles were obtained for different amounts of the substance deposited on the subphase. Layers on the aqueous subphase surface were studied using a Brewster microscope and measurements of the surface potential. Comparison of the obtained data made it possible to determine the stage of the formation of a continuous RGO layer.
Show AbstractA mixture of A and B monomers without shape anisotropy but that are capable of forming three types, viz., AA, BB, and AB mesogenic dimers is investigated. The possibility of a temperature transition from one nematic phase consisting mainly of AB dimer formed by monomers of different types into another nematic phase consisting mainly of AA and BB dimers formed by monomers of the same type is shown.
Show AbstractUsing molecular modeling we have shown that low-molecular-weight gelator molecules, which are able to form long and thin strings in dilute isotropic solutions, do not have any notable shape features. They have neither preferred axes nor visual asymmetry. Thus we confirm a crucial role of chirality itself as molecule asymmetry in the formation of macroscopic helicity.
Show AbstractThe patterns of changes of the spectral shapes of the fluorescence of bean leaves have been identified under low-light conditions of plant cultivation and decrease in chlorophyll concentration in the leaves. Under these experimental conditions, the ratio of peak intensities of fluorescence in the red spectral region, w=F$_{740}$/F$_{685}$, which was recorded after the end of the induction period, was proportional to the chlorophyll content per 1 g of the wet weight of a leaf.
Show AbstractExperimental data to confirm the possibility of the usage of polysaccharides as adjuvants were obtained. Immunoadjuvant activity of polysaccharide ADVA when used in conjunction with antigens of different structures and chemical natures: sheep red-blood cells, meningococcal polysaccharide antigen, tetanus exotoxin protein, and hemagglutinin of influenza virus were studied. The structure of the polysaccharide ADVA was characterized by the IR-spectroscopy and GC methods. It was shown that ADVA is non-toxic. The possibility of using ADVA as an immunoadjuvant is discussed.
Show AbstractA mathematical model of a relativistic effect that arises in the process of laser ranging of artificial Earth satellites (AESs) from the surface of the Earth is constructed. A numerical calculation algorithm is developed and the amplitude of this effect is calculated as a function of the AES orbital position. It is shown that this effect may be measured in the process of ranging of current Russian AESs equipped with laser corner reflectors.
Show AbstractA nonlinear theory of storm surges was constructed. The results are compared with observation data.
Show AbstractIn the framework of the linear long-wave theory, we derive a system of equations that describe the potential and vortex residual hydrodynamic fields that arise in a rotating stratified (two-layer) ocean during tsunami generation by coseismic deformations of the ocean bottom. For the model case of a cylindrically symmetric ocean bottom deformation, we find an approximate analytical solution of the problem. Based on this solution, we analyze the specific features of residual fields due to the presence of stratification for conditions that are typical of real tsunami sources.
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