Neuromorphic elements and systems as the basis for the physical implementation of artificial intelligence technologies

The instrumental realization of neuromorphic systems may form the basis of a radically new social and economic setup, redistributing roles between humans and complex technical aggregates. The basic elements of any neuromorphic system are neurons and synapses. New memristive elements based on both organic (polymer) and inorganic materials have been formed, and the possibilities of instrumental implementation of very simple neuromorphic systems with different architectures on the basis of these elements have been demonstrated.     

CP -violation effects in the decays B ? → D * K *? and method for determining the weak phase γ

A method for determining the angle γ and the ratio of the amplitudes A _λ(B ⁻ → K ^*−) and A _λ)B ⁻ → D ^*0 K ^*−), r _Bλ, for all three vector-meson polarization states by using the decays B ^∓ → D ^* K ^*∓ is proposed. This method relies on the interference between the decays B ⁻ → D ^*0 K ^*− and B ⁻ → K ^*−, which arises if D ^*0 and decay to D ⁰/ π ⁰ and D ⁰/ γ, whereupon D ⁰ and mesons decay to common final hadron states. The doubly Cabibbo-suppressed modes of D ⁰-meson decay are chosen here to specify such final states. Original Russian Text ? V.A. Kovalchuk, 2007, published in Yadernaya Fizika, 2007, Vol. 70, No. 4, pp. 754–763.     

Analytical model of light-emitting diode with patterned contact

In this paper we develop an analytical model for the light-emitting diode (LED) with the metal p-contact patterned as an array of thin strips. The model is based on conformal mapping approach and accounts for the overlapped fringing electric fields created by the adjacent strips. We derive analytical expressions for the electric potential, current injected into the LED active region and power of light extracted via the openings in the pattern. Spatial distribution of electric potential and LED radiation pattern are calculated. Further investigations are necessary to elucidate the contribution of the side walls of the strips on the LED output performance.     

Study of structural order in porphyrin-fullerene dyad ZnDHD6ee monolayers by electron diffraction and atomic force microscopy

The structure of porphyrin-fullerene dyad ZnDHD6ee monolayers formed on the surface of aqueous subphase in a Langmuir trough and transferred onto solid substrates has been studied. The data obtained are interpreted using simulation of the structure of isolated molecules and their packing in monolayer and modeling of diffraction patterns from molecular aggregates having different sizes and degrees of order. Experiments on the formation of condensed ZnDHD6ee monolayers are described. The structure of these monolayers on a water surface is analyzed using π-A isotherms. The structure of the monolayers transferred onto solid substrates is investigated by electron diffraction and atomic force microscopy. The unit-cell parameters of two-dimensional domains, which are characteristic of molecular packing in monolayers and deposited films, are determined. Domains are found to be organized into a texture (the molecular axes are oriented by the [001] direction perpendicular to the substrate). The monolayers contain a limited number of small 3D domains.     

Mechanical twinning of yttrium oxide single crystals

The deformation structure of an yttrium oxide single crystal under point load was studied by microhardness and electron microscopy. It was concluded that mechanical twinning is the main mechanism of plastic deformation of these single crystals. A twin was simulated by rotating the structure around the three-fold axis. It was shown that the average change of the distance between anions was about 5% and that between cations was 15%. The comparison with the structure of the regions of the fluorite single crystals and optical ceramics deformed in the analogous manner was performed.     

Control of the crystal lattice strain gradient caused by low-frequency ultrasound

The opportunities of dynamic control of the ultrasound-induced strain gradient in germanium crystal lattice have been studied. Two methods of gradient strain control are offered, which are based on variation in the (i) frequency and (ii) amplitude of ultrasonic vibrations. Both methods have been experimentally implemented.     

Raman study of ethylene-propylene copolymers and polyethylene-polypropylene reactor blends

The Raman spectra of the ethylene-propylene copolymers (EPC) synthesized using new metallocene catalytic systems and the polypropylene/polyethylene/diblockcopolymer of propylene and ethylene (PP/PE/DBC) blends obtained using the sequential polymerization are studied. The copolymer and reactor blend spectra are analyzed using the Raman spectra of a series of liquid n-alkanes. Significant monotonic changes are observed in the spectra of EPC and the PP/PE/DBC blends when the ethylene content increases. Substantial differences between the series of samples of blends and copolymers are revealed. In contrast to the EPC spectra, the spectra of the PP/PE/DBC reactor blends are represented as an exact superposition of the homopolymer spectra with the weight coefficients proportional to the contents of the blend components. A monotonic blue shift of the line that corresponds to the symmetric stretching mode of the CH₂ groups is observed in the EPC Raman spectra when the ethylene content increases. It is demonstrated that, for this line, the peak position only depends on the relative content of comonomers and does not depend on the contents of the PP and PE crystalline phases. The intensity ratio of two fundamental vibrations of PE and PP with frequencies of 1295 and 1330 cm^?1 can be used to determine the relative contents of the PE molecules in the trans-conformation and PP macromolecules in the helical conformation in the PP/PE blends. It is demonstrated that variations in the Raman spectra of n-alkanes, EPC, and PP/PE/DBC reactor blends related to variations in the relative contents of various chemical groups are reliably traced in the spectra of all of the materials under study.     

Electron-beam-pumped high-power wide-aperture exciplex lasers and laser systems

High-efficiency, high-power pulsedXeCl ^* andKrF ^* lasers pumped with an electron beam and laser systems based on these lasers have been developed. This paper describes the principles embodied in their development and design. The results of investigations on the formation of high-quality, high-power pulses are presented. Pulses with a radiation energy of up to 2000 and 100 J have been obtained at λ=308 and 249 nm, respectively, with a minimum 10 μrad divergence of the beam. Institute of High-Current Electronics, Siberian Division of the Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 12–18, April, 2000.