Optical absorption of BaF[2] crystals with different prehistory when irradiated by high-energy electrons

The spectra of stable optical absorption of BaF[2] crystals containing uncontrollable impurities after irradiation with 3 MeV electrons are studied at room temperature. The dependence of the efficiency of stable color accumulation in the region of emerging cross-luminescence on the absorption coefficients measured near the fundamental absorption edge in unirradiated crystals of various prehistory is traced

Mathematical modelling of energy conversion of pulsed electron beam in BaF[2] crystal

This paper presents the results of mathematical modeling of spatiotemporal distribution of energy in a BaF[2] crystal in an area of dissipation of energy of an pulsed electron beam. Fluence is varied from 0.188 to 0.626 J/cm{2}. Electron beam pulse duration was 24 ns, and the maximum electron energy of 280 KeV. Based on the obtained of energy distributions temperature change of the material during irradiation were calculated

Kinetic characteristics of the luminescence decay for industrial yttrium-gadolinium-aluminium garnet based phosphors

The spectral and decay kinetic characteristics of pulse cathodoluminescence and photoluminescence of phosphors based on yttrium-gadolinium-aluminum garnet were investigated using pulsed optical time resolved spectroscopy

Comparative physical-tribological properties of anti-friction ion-plasma Ti-C-Mo-S coating on VT6 alloy or 20X13 and 40X steels

Results of comparative tests mechanical and tribological properties of solid antifriction Ti-C-Mo-S coating, deposited by magnetron-plasma combined sputtering method on substrates of VT6 titanium alloy, 40X and 20X13 hardened steels are provided. Coating is sputtered using the same conditions and technological regimes on substrates of different materials. However, the friction tests results showed significant difference in tribological characteristics of coating depending on type of material used for substrate, first of all by wear-resistance ability. Authors suppose that this is due to difference between physical properties such as composition and structure of substrate materials that determines hardness and coating adhesion to surface

Direct evidence for flat bands in twisted bilayer graphene from nano-ARPES

Transport experiments in twisted bilayer graphene revealed multiple superconducting domes separated by correlated insulating states. These properties are generally associated with strongly correlated states in a flat mini-band of the hexagonal moir\'e superlattice as it was predicted by band structure calculations. Evidence for such a flat band comes from local tunneling spectroscopy and electronic compressibility measurements, reporting two or more sharp peaks in the density of states that may be associated with closely spaced van Hove singularities. Direct momentum resolved measurements proved difficult though. Here, we combine different imaging techniques and angle resolved photoemission with simultaneous real and momentum space resolution (nano-ARPES) to directly map the band dispersion in twisted bilayer graphene devices near charge neutrality. Our experiments reveal large areas with homogeneous twist angle that support a flat band with spectral weight that is highly localized in momentum space. The flat band is separated from the dispersive Dirac bands which show multiple moir\'e hybridization gaps. These data establish the salient features of the twisted bilayer graphene band structure.Comment: Submitted to Nature Materials. Nat. Phys. (2020

Контейнерная поточно-транспортная технология подготовки селекционного зерна

Abstract. Low-level mechanization is one of the main reasons for the high costs in selection and primary seed production. Crop breeders use transport and loading facilities for seed material transporting in an unsystematic manner. (Research purpose) Development of technology of transport support in selection and seed production, including all transport and loading processes of the delivery of grain seeds from selection combines to storage facilities using containers for seed collection, transportation, drying, and storage. (Materials and methods) The authors have described a container flowtransport technology of selection grain harvesting at the stage of primary reproduction and developed a machine complex technology and a database of harvesting and transport machines for seed collection, transportation, drying, and storage. (Results and discussion) The authors have determined the type of transport and loading means for the container method of seed harvesting, transportation and storage recommended for use in selection and seed production. There are four distinctive novelty positions of the presented type: the ability to transport containers in 2 rows; increased loading height from 2 m to 3 m; maximum operating radius reaches 3.8 m (vs. 2.7 m); increased cargo capacity – by 460 kg. (Conclusions) The authors suggest using the developed methodology to improve the technological process of harvesting, transportation and postharvest processing of seed grain, organize this process, as well as select machine parameters and technical equipment on the farms of the Central region of Russia. It has been suggested that test prototypes of containers and a loader with a container tilter should be designed and manufactured for use in primary crop processing.Реферат. Низкий уровень механизации – одна из главных причин высоких затрат в селекции и первичном семеноводстве. Селекционеры бессистемно пользуются транспортными и погрузочными средствами для перевозки семенного материала. (Цель исследования) Разработать технологию транспортного обеспечения в селекции и семеноводстве, включающую в себя все транспортно-погрузочные процессы доставки семян зерновых культур от селекционных комбайнов до хранилищ с использованием контейнера для сбора, транспортировки, сушки и хранения семян. (Материалы и методы) Описали контейнерную поточно-транспортную технологию заготовки селекционного зерна на этапе первичного размножения. Разработали машинный комплекс технологии и базу данных уборочных и транспортных машин для сбора, транспортировки, сушки и хранения семян. (Результаты и обсуждение) Определили типаж транспортных и погрузочных средств при контейнерном способе уборки, транспортирования и хранения семян, рекомендуемых для применения в селекции и семеноводстве. Отличие типажа по новизне представили четырьмя позициями: возможность перевозить контейнеры в 2 ряда; увеличение высоты погрузки с 2 до 3 м; набольший вылет стрелы достигает 3,8 м (против 2,7 м); грузоподъемность выше на 460 кг. (Выводы) Рекомендовали использовать разработанную методику для совершенствования технологического процесса уборки, транспортировки и послеуборочной обработки семенного зерна, организации этого процесса, а также выбора параметров средств и технической оснащенности в хозяйствах Центрального региона России. Предложили разработать и изготовить опытные образцы контейнеров и погрузчика с кантователем контейнеров для первичной переработки урожая

Phenological shifts of abiotic events, producers and consumers across a continent

Ongoing climate change can shift organism phenology in ways that vary depending on species, habitats and climate factors studied. To probe for large-scale patterns in associated phenological change, we use 70,709 observations from six decades of systematic monitoring across the former Union of Soviet Socialist Republics. Among 110 phenological events related to plants, birds, insects, amphibians and fungi, we find a mosaic of change, defying simple predictions of earlier springs, later autumns and stronger changes at higher latitudes and elevations. Site mean temperature emerged as a strong predictor of local phenology, but the magnitude and direction of change varied with trophic level and the relative timing of an event. Beyond temperature-associated variation, we uncover high variation among both sites and years, with some sites being characterized by disproportionately long seasons and others by short ones. Our findings emphasize concerns regarding ecosystem integrity and highlight the difficulty of predicting climate change outcomes. The authors use systematic monitoring across the former USSR to investigate phenological changes across taxa. The long-term mean temperature of a site emerged as a strong predictor of phenological change, with further imprints of trophic level, event timing, site, year and biotic interactions.Peer reviewe