Surface acoustic wave modulation of single photon emission from GaN/InGaN nanowire quantum dots

On-chip quantum information processing requires controllable quantum light sources that can be operated on-demand at high-speeds and with the possibility of in-situ control of the photon emission wavelength and its optical polarization properties. Here, we report on the dynamic control of the optical emission from core-shell GaN/InGaN nanowire (NW) heterostructures using radio frequency surface acoustic waves (SAWs). The SAWs are excited on the surface of a piezoelectric lithium niobate crystal equipped with a SAW delay line onto which the NWs were mechanically transferred. Luminescent quantum dot (QD)-like exciton localization centers induced by compositional fluctuations within the InGaN nanoshell were identified using stroboscopic micro-photoluminescence (micro-PL) spectroscopy. They exhibit narrow and almost fully linearly polarized emission lines in the micro-PL spectra and a pronounced anti-bunching signature of single photon emission in the photon correlation experiments. When the nanowire is perturbed by the propagating SAW, the embedded QD is periodically strained and its excitonic transitions are modulated by the acousto-mechanical coupling, giving rise to a spectral fine-tuning within a ~1.5 meV bandwidth at the acoustic frequency of ~330 MHz. This outcome can be further combined with spectral detection filtering for temporal control of the emitted photons. The effect of the SAW piezoelectric field on the QD charge population and on the optical polarization degree is also observed. The advantage of the acousto-optoelectric over other control schemes is that it allows in-situ manipulation of the optical emission properties over a wide frequency range (up to GHz frequencies).Comment: arXiv admin note: text overlap with arXiv:1902.0791

Software selection based on analysis and forecasting methods, practised in 1C

The research focuses on the problem of a "1C: Enterprise 8" platform inboard mechanisms for data analysis and forecasting. It is important to evaluate and select proper software to develop effective strategies for customer relationship management in terms of sales, as well as implementation and further maintenance of software. Research data allows creating new forecast models to schedule further software distribution

Preparation of pine flotation oil by hydration with α-pinene

The hydration of α-pinene of gum turpentine and separately pinene fractions in the organic acids media for the purpose of obtaining terpene alcohols, which are widely used as flotation reagent for mineral processing in mining production were studied. The best results are obtained among the organic acids when 70% formic acid is used. The α-pinene hydration process in the acid imedium is exothermic, and it is necessary to maintain a constant temperature of 65 °C to reduce the rate of side reactions. The main component of turpentine, resulting in the formation of α-terpineol is α-pinene; 3-carene, terpinolene, and limonene contents do not practically change in the reaction mixture, which testify their stability in 70% formic acid media. The maximum content of terpene alcohols (60,1%) was obtained when using α-pinene fraction at a ratio of α-pinene and 70% formic acid 1.0 : 1.1 for 3 hours. Increase of the duration of hydration reaction leads to the decrease in the content of terpineol in the reactio n mixture due to the secondary isomerization processes

Informational and analytical support of social and labor aspects of an urban settlement

Purpose: The aim of this article is to identify and assess the key problems of the city of Rostov-on-Don in social and labor aspects in order to determine the competitive position of the city relative to the million-plus cities regarding its advantages and key trends. Structure/Methodology/Approach: To realize the goals of strategic planning, it seems appropriate: first, to obtain an analytical assessment of the state of the social and labor sphere of the city of Rostov-on-Don; second, to obtain a comparative assessment of the state relative to the cities of one million Russian citizens; third, to formulate the key problems that have arisen in this field and, fourth, to formulate the competitive position of the city of Rostov-on-Don. Results: To arrange strategic directions for the development of the city of Rostov-on-Don, authors determined the competitive position of the city in the social and labor sphere in the form of advantages, key problems and key trends. Practical implications: The results could be implemented at the municipality level in the formation of the spatial policy of urban development and improving the quality of life of the population. Originality/Value: The main contribution of this study is to implement a system approach to the process of improving and developing information and analytical support for the management of municipal territories.peer-reviewe

Fumaric acid amides in technologies of paper and cardboard

Fumaric acid polyamids were synthesized by interaction of fumaric acid with polyamines (diethylenetriamine, triethylenetetramine) by equilibrium polycondensation in the melt. The obtained products are promising as hardening additives in the technology of paper and cardboard. This article studies the type and rate effects of fumaric acid polyamides on some paper strength properties (breaking length, breaking force in dry and wet states). It is shown that the greatest effect of the paper hardening is achieved by using the additive, which is a product of polycondensation of fumaric acid and diethylenetriamine

Under the influence of new educational technologies: the theory of electrolytic dissociation

The article describes a computer programs for study of the chemistry section, training calculations and knowledge testРассмотрены компьютерные программы для изучения студентами химии, выполнения ими практических заданий и проверки знани