Probe microscopy in the study of the process of template synthesis

This work was supported by the Federal Agency of Scientific Organizations (Agreement No 007-ГЗ/Ч3363/26). The authors thank O.Rybalko (MIEM) and V.Lavrentiev (INP, Rezh, Czech Republic) for their assistance in conducting the experiments

Enhanced Luminescence in InGaN Multiple Quantum Wells with Quaternary AlInGaN Barriers

We report on the comparative photoluminescence studies of AlGaN/GaN, GaN/InGaN, and AlInGaN/InGaN multiple quantum well(MQW) structures. The study clearly shows the improvement in materials quality with the introduction of indium. Our results point out the localized state emission mechanism for GaN/InGaN structures and the quantum well emission mechanism for AlInGaN/InGaN structures. The introduction of indium is the dominant factor responsible for the observed differences in the photoluminescence spectra of these MQW structures

INTEGRATION OF THE FOOD INDUSTRY AND RELATED SECTORS BASED ON THE CLUSTER APPROACH

In a diversified agro-industrial complex structure of the Voronezh region there are more than 200 enterprises of food and processing industry. However, due to the growth disparity in prices for agricultural and industrial products, the collapse of a single process has been a sharp decline in the production of final products of agribusiness. In the conditions of Russia's accession to the WTO and the growth in this regard competition in the market of raw materials and finished products, problems of high relevance of search for effective strategies for the development of the food industry. The emphasis of these reforms should be a priori biased towards the crea tion of favorable conditions for the formation of optimal institutional innovation structures and prospects of development of the national agro-food system at all levels. In this regard, the formation of institutional models of integration in the agricultural sector, we regard the system approach, where the newly created integrated structure is defined as a social institution, characterized by composition, structure, objectives, functions, internal and external bounding box defined inputs and outputs. Under these conditions, there is a need to develop partnerships and coo peration between enterprises of the technological chain of the final product agribusiness, finds its expression in a variety of forms, one of which is the formation of clusters, creating the conditions for effective interaction of producers of raw materials and finished products, research and educational institutions, service infrastructure of organizations and representatives of other areas to ensure. However, the analysis showed that, across a variety of alternative strategies for the development of the food industry, the most optimal in today's economic conditions appear to integration strategies that involve the union of disparate market participants on the principles of economic integr ation, which results in a synergy by eliminating irrational mediation

High-Quality p-n Junctions with Quaternary AlInGaN/InGaN Quantum Wells

We report on quaternary AlInGaN/InGaN multiple quantum well(MQW)light emitting diode structures grown on sapphire substrates. The structures demonstrate high quality of the p–njunctions with quaternary MQW. At low forward bias (below 2 V), the temperature dependent of current–voltage characteristics are exponential with the ideality factor of 2.28, which is in a good agreement with the model of the injected carrier recombination in the space charge region. This ideality factor value is approximately three times lower than for conventional GaN/InGaN light emitting diodes(LEDs). The obtained data indicate the recombination in p–njunction space charge region to be responsible for a current transport in LED structures with quaternary quantum wells. This is in contrast to InGaN based LEDs, where carrier tunneling dominates either because of high doping of the active layer or due to the high density of localized states

Ultraviolet Light-Emitting Diodes at 340 nm using Quaternary AlInGaN Multiple Quantum Wells

An ultraviolet light-emitting diode with peak emission wavelength at 340 nm is reported. The active layers of the device were comprised of quaternary AlInGaN/AlInGaN multiple quantum wells, which were deposited over sapphire substrates using a pulsed atomic-layer epitaxy process that allows precise control of the composition and thickness. A comparative study of devices over sapphire and SiC substrates was done to determine the influence of the epilayer design on the performance parameters and the role of substrate absorption

Selective Area Deposited Blue GaN-InGaN Multiple-Quantum Well Light Emitting Diodes over Silicon Substrates

We report on fabrication and characterization of blue GaN–InGaN multi-quantum well (MQW)light-emitting diodes(LEDs) over (111) silicon substrates. Device epilayers were fabricated using unique combination of molecular beam epitaxy and low-pressure metalorganic chemical vapor depositiongrowth procedure in selective areas defined by openings in a SiO2mask over the substrates. This selective area deposition procedure in principle can produce multicolor devices using a very simple fabrication procedure. The LEDs had a peak emission wavelength of 465 nm with a full width at half maximum of 40 nm. We also present the spectral emission data with the diodes operating up to 250 °C. The peak emission wavelengths are measured as a function of both dc and pulse bias current and plate temperature to estimate the thermal impedance

Low-Temperature Operation of AlFaN Single-Quantum-Well Light-Emitting Diodes with Deep Ultraviolet Emission at 285 nm

We present a study of the electrical and optical characteristics of 285 nm emission deep ultraviolet light-emitting diodes(LED) at temperatures from 10 to 300 K. At low bias, our data show the tunneling carrier transport to be the dominant conduction mechanism. The room-temperature performance is shown to be limited mostly by poor electron confinement in the active region and a pronounced deep level assisted recombination but not by the hole injection into the active region. At temperatures below 100 K, the electroluminescence peak intensity increases by more than one order of magnitude indicating that with a proper device design and improved material quality, milliwatt power 285 nm LED are viable

Exact solution of the Mindlin–Herrmann model for longitudinal vibration of an isotropic rod

This paper presents a new approach to the problem of coupled longitudinal and transversal propagation of stress waves in an isotropic thick and elastic rod, based on the Mindlin-Herrmann theory. The novelty is that, the Hamilton vriational principle is used not only for derivation of the governing equations and set of natural boundary conditions, but also for obtaining the exact solution in terms Green functions directly from the Langrangian. The success of this approach is based on the existence of multiple orthogonalities of the eigenfuctions. The proposed method is much easier than the standard approach of building Green functions. A numerical example illustrates the method of finding eigenfrequencies and eigenfunctions for isotropic Mindlin-Herrmann rod.National Research Foundation (NRF) of South Africa (Grant No: 85177)http://link.springer.com/journal/106652017-08-30hb201

Band-Edge Luminesce in Quaternary AlInGaN Light-Emitting Diodes

Operation of InGaNmultiple-quantum-well(MQW)light-emitting diodes(LEDs) with quaternary AlInGaN barriers at room and elevated temperatures is reported. The devices outperform conventional GaN/InGaN MQWLEDs, especially at high pump currents. From the measurements of quantum efficiency and total emitted power under dc and pulsed pumping, we show the emission mechanism for quaternary barrier MQWs to be predominantly linked to band-to-band transitions. This is in contrast to localized state emission observed for conventional InGaN/InGaN and GaN/InGaN LEDs. The band-to-band recombination with an increased quantum-well depth improves the high-current performance of the quaternary barrier MQWLEDs, making them attractive for high-power solid-state lighting applications

Генератор чистого водорода

Тhe results of works about the creation of hydrogen generator on the basis of solid polymeric electrolyte was given.Представлены результаты проведенных работ по созданию генератора водорода на основе применения твердополимерного электролита