Detection of dust grains vibrations with a laser heterodyne receiver of scattered light

We present the results of measurement of grains vibrations under external action in gas and liquid with a laser heterodyne receiver of scattered radiation. For investigation of dynamic characteristics of particles we made the laser heterodyne receiver with sensitivity about 2×10⁻¹⁷ W/Hz and source of probing with radiation power 1 mW. In our pilot experiments, measurement of vibration amplitude of nanoparticles in gas (cigarette smoke) and microparticles in fluid (toothpaste in water) was made. We measured values of vibration amplitudes about 20–30 nm.     

Nonnegative non-redundant tensor decomposition

Nonnegative tensor decomposition allows us to analyze data in their ‘native’ form and to present results in the form of the sum of rank-1 tensors that does not nullify any parts of the factors. In this paper, we propose the geometrical structure of a basis vector frame for sum-of-rank-1 type decomposition of real-valued nonnegative tensors. The decomposition we propose reinterprets the orthogonality property of the singularvectors of matrices as a geometric constraint on the rank-1 matrix bases which leads to a geometrically constrained singularvector frame. Relaxing the orthogonality requirement, we developed a set of structured-bases that can be utilized to decompose any tensor into a similar constrained sum-of-rank-1 decomposition. The proposed approach is essentially a reparametrization and gives us an upper bound of the rank for tensors. At first, we describe the general case of tensor decomposition and then extend it to its nonnegative form. At the end of this paper, we show numerical results which conform to the proposed tensor model and utilize it for nonnegative data decomposition.     

Shape and location of multiple charge carriers in linear π‐electron systems

We have performed a quantum‐mechanical study of a series of neutral polyenes, their multiply charged ions, and related ionic polymethines with a closed electron shell, using different methods/basis with/without electron correlations. The study shows that a multiple injection of charge carriers into a collective system of π‐electrons causes a formation of distinctive electron levels in the energy gap along with a simultaneous regular gap shift in accordance to the number of injected carriers. Each charge generates its own solitonic electron density alternation wave on adjacent carbon atoms, as well as similar bond length and valence angle alternation waves. Established regularities in charge distribution and variations of bond lengths and valence angles may be used in the molecular design of organic semiconducting materials. © 2013 Wiley Periodicals, Inc.     

Multifunctional controlled IR-emitting unit

We present the results of our investigations of a multifunctional emitting unit based on p⁺–p–p⁺-Ge structure with anisotropic conductivity induced by a magnetic field. It is shown that the presence of complex controlled concentration profiles in the structure greatly increases the performance of the emitting unit, enabling one to simulate positive, negative or alternating contrasts. This makes it possible to use this unit as the basis of special emission sources intended for calibration of infrared systems.     

Anisotropic and polarized intraband light emission of hot electrons

Far infrared luminescence of hot electrons in InSb have been studied. The emission probabilities derived in the second order perturbation are obtained for different scattering mechanisms: acoustic phonons, optical phonons and impurities. The origin of anisotropy and polarization of the light emission due to anisotropy of the electron distribution function under the electric field is described theoretically and calculated using the Monte Carlo method. The theoretical conclusions are confirmed by the experiment.     

Hydroxy and Methoxy Substituted Thiacarbocyanines for Fluorescent Detection of Amyloid Formations

In present paper series of trimethine cyanines modified in 5,5′- or 6,6′- position with hydroxy- or methoxy- substituents is studied for their ability to interact selectively with fibrillar formations. Processes of dye aggregation that accompany this interaction were also investigated. Meso-methyl trimethynecyanines with 5,5′- methoxy (7519) and hydroxy (7515) substituents strongly (up to 40 times) increase fluorescence intensity in the presence of fibrillar insulin, and also give noticeable fluorescent response on the presence of various aggregated proteins (lysozyme, β-lactoglobulin, α-synuclein A53T). 7519 and 7515 dyes can be used for fluorometric detection of fibrillar insulin at concentrations of approximately 1.5–120 microg/ml. For meso-ethyl substituted dye 7514 the ability to form H- and J-aggregates upon interaction with insulin fibrils was suggested. The model of the H- and J-aggregate packing in the protein fibrillar structure has been proposed.