Controlling split-ring resonators with light

We propose an original approach for creating tunable electromagnetic metamaterials. We demonstrate experimentally that magnetic resonance of a split-ring resonator (“meta-atom” of a composite material) with a photodiode operated in photovoltaic mode can be tuned by changing the intensity of an external light source. Moreover, for two coupled resonators, we show that we can achieve light-induced switching between dark- and bright-mode responses.The authors acknowledge a support from the Ministry of Education and Science of the Russian Federation, Dynasty Foundation (Russia), the Engineering and Physical Sciences Research Council (UK), and the Australian Research Council (Australia)

Study of strength properties of semi-finished products from economically alloyed high-strength aluminium-scandium alloys for application in automobile transport and shipbuilding

The results of a study on the strength of rolled products from aluminium alloys doped with scandium under various processing conditions of hot and cold rolling are presented. The regularities of metal flow and the level of strength of deformed semi-finished products from aluminum-scandium alloys are established, depending on the total degree of deformation and the various modes of single reduction during rolling. It is shown that when using one heating of a cast billet to obtain high-quality semi-finished products, the temperature during the rolling process should not be lower than 350-370°, and the total degree of deformation does not exceed 50-60%. It was found that the semi-finished products from alloys with a content of scandium in the range 0.11-0.12% in the deformed state had elevated values of ultimate tensile strength and yield strength of the metal, which allows them to be recommended for industrial production of sheet metal product

THE STUDY OF THE STRUCTURE OF CAST AND DEFORMED SEMIFINISHED PRODUCTS FROM ALUMINUM ALLOYS DOPED WITH SCANDIUM ECONOMICALLY

Изучена микроструктура опытных сплавов системы Al–Mg, экономно легированных скандием в литом, деформированном и отожженном состоянии. Установлено, что микроструктура всех образцов представляет собой твердый раствор на основе алюминия и частицы различных фаз, расположенных преимущественно по границам зерен, вытянутых в направлении деформации. Такая структура обеспечивает сравнительно высокие механические свойства листового проката, при этом с помощью отжига имеется возможность повышать его пластические характеристики.Given the microstructure of the experimental alloys of the system Al–Mg alloy with scandium economically as-cast, deformed and annealed condition. It is established that microstructure of all the samples after deformation contains intermetallic phase located mostly at the grain boundaries along the direction of deformation

PROPERTIES OF ALUMINUM ALLOYS DOPED WITH SCANDIUM ECONOMICALLY, AFTER DEFORMATION AND THERMAL EFFECTS

Приведены результаты исследований прочностных и пластических свойств прокатанных полос из экспериментальных алюминиевых сплавов, содержащих различное количество скандия. Получены зависимости механических свойств новых сплавов от химического состава сплавов, степени деформации при горячей и холодной прокатке, температуры отжига. Установлено, что наиболее близкими к требуемым свойствами обладает сплав с содержанием скандия 0,14 %.Strength and plastic properties research results of rolled strips from experimental aluminium alloys that containing different amounts of scandium represented. Dependences of mechanical properties for new alloys from chemical composition of alloys, deformation degree during hot and cold rolling, temperature of annealing were obtained. Determined that closest to the required properties has alloy containing 0,14 % of scandium

Study of Bars and Wires Properties from Al-REM System Alloy

The article presents the results of studies on the production of wire with a diameter of 0,5 mm from aluminum alloy 01417 with a content of rare-earth metals (REM) in the amount of 7–9 % for aircraft construction needs. The deformation modes, the experimental technique and equipment for the implementation of the proposed technology are described.В статье представлены результаты исследований по получению проволоки диаметром 0,5 мм из алюминиевого сплава 01417 с содержанием редкоземельных металлов (РЗМ) в количестве 7–9 % для нужд авиастроения. Описаны режимы деформации, методика проведения экспериментов и оборудование для реализации предложенной технологии.Исследования выполнены при финансовой поддержке РФФИ, Правительства Красноярского края и ООО «Научно-производственный центр Магнитной гидродинамики» в рамках научного проекта № 18-48-242021 «Разработка фундаментальных основ получения деформированных полуфабрикатов электротехнического назначения из высоколегированных сплавов системы Al-РЗМ с применением методов совмещенной обработки и исследование их реологических свойств»

Herschelobservations of the W3 GMC (II): clues to the formation of clusters of high-mass stars

The W3 giant molecular cloud is a prime target for investigating the formation of high-mass stars and clusters. This second study of W3 within the HOBYS Key Program provides a comparative analysis of subfields within W3 to further constrain the processes leading to the observed structures and stellar population. Probability density functions (PDFs) and cumulative mass distributions (CMDs) were created from dust column density maps, quantified as extinction AV. The shape of the PDF, typically represented with a lognormal function at low Av “breaking” to a power-law tail at high Av, is influenced by various processes including turbulence and selfgravity. The breaks can also be identified, often more readily, in the CMDs. The PDF break from lognormal (Av(SF)» 6–10 mag) appears to shift to higher Av by stellar feedback, so that high-mass star-forming regions tend to have higher PDF breaks. A second break at Av> 50 mag traces structures formed or influenced by a dynamic process. Because such a process has been suggested to drive high-mass star formation in W3, this second break might then identify regions with potential for hosting high-mass stars/clusters. Stellar feedback appears to be a major mechanism driving the local evolution and state of regions within W3. A high initial star formation efficiency in a dense medium could result in a self-enhancing process, leading to more compression and favorable star formation conditions (e.g., colliding flows), a richer stellar content, and massive stars. This scenario would be compatible with the “convergent constructive feedback” model introduced in our previous Herschel study

ДОСЛІДЖЕННЯ ЕНЕРГОНАВАНТАЖЕНОСТІ ФРИКЦІЙНОГО ЗЧЕПЛЕННЯ КОЛІСНИХ МАШИН

A mathematical model of slippage is developed of clutch. Investigations of energy loading of the friction clutch of an armored wheeled vehicle were conducted and the degree of influence of the main design and operational factors on the energy loading of the clutch.Розроблено математичну модель буксування зчеплення. Проведено дослідження енергонавантаженості фрикційного зчеплення броньованої колісної машини та визначено ступінь впливу основних конструктивних і експлуатаційних факторів на енергонавантаженість зчеплення