Quantum spectroscopy of plasmonic nanostructures

We use frequency entangled photons, generated via spontaneous parametric down conversion, to measure the broadband spectral response of an array of gold nanoparticles exhibiting Fano-type plasmon resonance. Refractive index sensing of a liquid is performed by measuring the shift of the array resonance. This method is robust in excessively noisy conditions compared with conventional broadband transmission spectroscopy. Detection of a refractive index change is demonstrated with a noise level 70 times higher than the signal, which is shown to be inaccessible with the conventional transmission spectroscopy. Use of low photon fluxes makes this method suitable for measurements of photosensitive bio-samples and chemical substances.Comment: 11 pages, 5 figure

Synthesis and properties of the materials obtained by SHS mode for radiation protection

The article shows the process of protective composite materials manufacturing. Also, the analysis of experimental results concerning the composite materials protective properties is given. The advantages of SHS method are considered in comparison with traditional materials. The uniqueness of SHS obtained products based on combination of nuclear-physical properties and parameters is presented

Photoassisted Synthesis of Complex Polyheterocycles via ESIPT-Driven Dearomative Intramolecular Cycloadditions

This research is focused on the development of novel photoassisted synthetic methodologies that provide straightforward access to complex and diverse libraries of polyheterocycles from modularly assembled precursors. All methods are based on the dearomative cycloadditions between two components: (i) o-azaxylylenes, generated by the excited-state intramolecular proton transfer, and (ii) tethered arene groups. We have demonstrated the synthetic utility of four new photoinduced processes that yield complex products amenable for post-photochemical modifications: [4+4] Cycloaddition of o-azaxylylenes to 1,3,4-oxadiazoles with subsequent dinitrogen extrusion. This reaction furnishes compounds outfitted with epoxide fragments, which undergo ring-openings with various nucleophiles; furthermore, the oxidized products rearrange into triazocanoindolinones under Schmidt reaction conditions. [4+2] Reaction between amino-o-azaxylylenes and tethered pyrroles. The primary pyrroline photoproducts are converted into stable polyheterocycles by 1,3-dipolar cycloaddition with tosyl azide and an intramolecular Friedel-Crafts reaction. Photodearomatization of benzenoid arenes via [2+4] reactions with o-azaxylylenes. This process transforms readily available benzene units into 1,3-cyclohexadienes, which are reactive in acid-catalyzed modifications and thermal [4+2] cycloadditions. Photocascade reaction involving [2+4] photocycloaddition of tethered anilines to o-azaxylylenes followed by secondary cyclization enabled by the oxalyl linker. This transformation permits strategic installation of specific functionalities into the photoproducts, with the purpose of further ring-forming modifications

Corrosion and Mechanical Properties of Austenic Steel Weld Joints

This paper presents results of experiments on how tungsten, molybdenum and aluminum oxyhydroxide nanopowders, imbedded into the weld pool, affect corrosion resistance and mechanical properties of welded joints. It is shown that nanopowders have a significant effect on the intergranular corrosion of the weld

MASTER prompt and follow-up GRB observations

There are the results of gamma-ray bursts observations obtained using the MASTER robotic telescope in 2007 - 2009. We observed 20 error-boxes of gamma-ray bursts this period.The limits on their optical brightnesses have been derived. There are 5 prompt observations among them, obtained at our very wide field cameras. Also we present the results of the earliest observations of the optical emission of the gamma-ray bursts GRB 050824 and GRB 060926.Comment: 10 pages, 2 figure

Structure control of La/B multilayer systems by partial nitridation

This PhD thesis contains a selection of thin film research results on the structure control of La/B multilayer mirrors with nm- and sub nm-thick layers, used at normal and grazing incidence of XUV radiation. Topics investigated include an improvement of the optical layer contrast, the reflectivity at 6.x nm wavelength, and the thermal stability. The approaches presented deal with in situ growth studies, deposition control and high resolution X-ray analysis

Probing magnetic and electric optical responses of silicon nanoparticles

We study experimentally both magnetic and electric optically induced resonances of silicon nanoparticles by combining polarization-resolved dark-field spectroscopy and near-field scanning optical microscopy measurements. We reveal that the scattering spectra exhibit strong sensitivity of electric dipole response to the probing beam polarization and attribute the characteristic asymmetry of measured near-field patterns to the excitation of a magnetic dipole mode. The proposed experimental approach can serve as a powerful tool for the study of photonic nanostructures possessing both electric and magnetic optical responses.This work was financially supported by Government of Russian Federation (Project Nos. 14.584.21.0009 10 and GOSZADANIE 2014/190, Zadanie No. 3.561.2014/K, 074- U01), Russian Foundation for Basic Research and the Australian Research Council

Master Robotic Net

The main goal of the MASTER-Net project is to produce a unique fast sky survey with all sky observed over a single night down to a limiting magnitude of 19 - 20mag. Such a survey will make it possible to address a number of fundamental problems: search for dark energy via the discovery and photometry of supernovas (including SNIa), search for exoplanets, microlensing effects, discovery of minor bodies in the Solar System and space-junk monitoring. All MASTER telescopes can be guided by alerts, and we plan to observe prompt optical emission from gamma-ray bursts synchronously in several filters and in several polarization planes.Comment: 10 pages, 8 figure