Initiation of Polarized State in the Tantalum Oxide Thin Films Grown by Magnetron Sputtering on a Substrate of Monocrystalline Silicon (100) Followed by Argon and Oxygen Ions

The pictures of the induced state and the surface potential distribution in thin films of tantalum oxide produced by magnetron sputtering onto a substrate of monocrystalline silicon (100) followed by low energy argon and oxygen ions was investigated by atomic force microscopy in spreading resistance and scanning Kelvin probe microscopy mode. It was shown that it is possible to polarize or depolarize the coating, and then to visualize the state of the induced polarization using an electric field applied via the conductive cantilever in contact spreading resistance microscopy mode. It was found that treatment with argon ions increases the contrast of the of the surface potential distribution maps from 1.2 V to 2,3 V for negative – 10 V voltage on the probe and from 9,6 V to 19,2 V for a positive + 10 V voltage in comparison with the oxygen ions

Research of Thermal Stability of Tapes of Diboride of Hafnium and Receipt of Optimization Model of Cutting Process

The short analysis of thermal stability and features of structure and physical-mechanical descriptions of thin wearproof coverages is executed on the basis of diborides of transitional metals, under act of high temperatures. The optimization model of cutting process is presented by the hard-alloy plate of Т15К6 with nanocrystalline tape of diboride of hafnium, by possessing the best physical-mechanical descriptions nanohardness of Н = 44,5 GPa and module of resiliency of Е = 396 GPa

Thermal Stability of Hafnium Diboride Films, Obtained on Substrates of Steel 12X18H9T and Cutting Plate T15K6

Investigation results of the influence of high-temperature annealing in the air environment on the phase structure and structure of hafnium diboride films, received on substrates from steel 12Х18Н9Т and cutting plate Т15К6 are presented. It is shown that in the course of annealing on a surface of HfВ2 film the oxide layer of HfО2, with monoclinic structure is formed. Thus, annealing temperature increase from 600 to 1000 С leads to increase in thickness of an oxide layer from 100 to 600 nanometers and to formation of a multilayered covering of HfB2 - HfO2. On substrates of steel 12Х18Н9Т the coating is destructed at the temperature higher on 800 C than for Т15К6. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3492

Temperature dynamics of the microdroplet fraction of metal plasma in plasma-optical devices with fast electrons

The computer simulation of a plasma filter with fast electrons shows that the main source of droplet heating is thermal electrons, while the role of fast electrons is reduced mainly to transferring energy to slow electrons. The processes of drop charging in the presence of an electron beam and the effective emission of electrons due are also considered.Комп’ютерне моделювання плазмового фільтра зі швидкими електронами показує, що основним джерелом нагріву краплі є теплові електрони, тоді як роль швидких електронів зводиться, в основному, до передачі енергії повільним електронам. Розглянуто також процеси заряджання краплі в присутності електронного пучка та ефективну емісію електронів за рахунок цього

Self-assembly routes towards creating superconducting and magnetic arrays

Using self-assembly from colloidal suspensions of polystyrene latex spheres we prepared well-ordered templates. By electrochemical deposition of magnetic and superconducting metals in the pores of such templates highly ordered magnetic and superconducting anti-dot nano-structures with 3D architectures were created. Further developments of this template preparation method allow us to obtain dot arrays and even more complicated structures. In magnetic anti-dot arrays we observe a large increase in coercive field produced by nanoscale (50–1000nm) holes. We also find the coercive field to demonstrate an oscillatory dependence on film thickness. In magnetic dot arrays we have explored the genesis of 3D magnetic vortices and determined the critical dot size. Superconducting Pb anti-dot arrays show pronounced Little-Parks oscillations in Tc and matching effects in magnetization and magnetic susceptibility. The spherical shape of the holes results in significantly reduced pinning strength as compared to standard lithographic samples. Our results demonstrate that self-assembly template methods are emerging as a viable, low cost route to prepare sub-micron structures

One-shot learning with triplet loss for vegetation classification tasks

Triplet loss function is one of the options that can significantly improve the accuracy of the One-shot Learning tasks. Starting from 2015, many projects use Siamese networks and this kind of loss for face recognition and object classification. In our research, we focused on two tasks related to vegetation. The first one is plant disease detection on 25 classes of five crops (grape, cotton, wheat, cucumbers, and corn). This task is motivated because harvest losses due to diseases is a serious problem for both large farming structures and rural families. The second task is the identification of moss species (5 classes). Mosses are natural bioaccumulators of pollutants; therefore, they are used in environmental monitoring programs. The identification of moss species is an important step in the sample preprocessing. In both tasks, we used self-collected image databases. We tried several deep learning architectures and approaches. Our Siamese network architecture with a triplet loss function and MobileNetV2 as a base network showed the most impressive results in both above-mentioned tasks. The average accuracy for plant disease detection amounted to over 97.8% and 97.6% for moss species classification.A.V.U. and A.V.N. gratefully acknowledge financial support from the Ministry of Science and Higher Education of the Russian Federation in accordance with agreement No 075-15-2020-905 dated November 16, 2020 on providing a grant in the form of subsidies from the Federal budget of Russian Federation. The grant was provided for state support for the creation and development of a World-class Scientific Center "Agrotechnologies for the Future". The database creation part of the reported study was funded by RFBR according to the research project No 18-07-00829

Development of NSC KIPT nuclear microprobe

Development of the microanalysis methods is stimulated by investigations of actual materials. Their properties depend not only on an atomic structure, but also on imperfections of this structure, phase composition, areas of impurity accumulation, various kinds of microinclusions etc. Characteristic sizes of these objects are usually ranged from a few parts of micron to several tens of micron. So, there is need for methods which provide the analysis of chemical elements in samples with the corresponding level of spatial resolution

Neutron fluxe measurements at the electrostatic electron accelerator “ELIAS”

Neutron fluxes were measured at an electron energy of 3 MeV, a current of 51 μA and a beryllium target thickness of 3 mm. Taking into account spare capacities for increasing the neutron flux, calculations were made of a maximum attainable thermal neutron fluence for a 3-hour exposure of the object, it was calculated to be ≅ 10¹⁰ n·cm⁻² .Измерены потоки нейтронов при энергии электронов 3 МэВ, токе 51 мкА и толщине нейтронопроизводящей мишени из бериллия 3 мм. С учетом имеющихся факторов увеличения потока нейтронов сделаны оценки максимально достижимого флюэнса тепловых нейтронов (за 3 часа экспозиции объекта), который составил ≅ 10¹⁰ н⋅см⁻².Виміряно потоки нейтронів при енергії електронів 3 МеВ, струмі 51 мкА та товщині нейтроногенеруючої мішені з берилію 3 мм. З урахуванням можливих факторів підвищення потоку нейтронів зроблено оцінки максимально досяжного флюенса теплових нейтронів (за 3 години експозиції об’єкта), що становить ≅ 10¹⁰ н⋅см⁻²

A note on two-loop superloop

We explore the duality between supersymmetric Wilson loop on null polygonal contours in maximally supersymmetric Yang-Mills theory and next-to-maximal helicity violating (NMHV) scattering amplitudes. Earlier analyses demonstrated that the use of a dimensional regulator for ultraviolet divergences, induced due to presence of the cusps on the loop, yields anomalies that break both conformal symmetry and supersymmetry. At one-loop order, these are present only in Grassmann components localized in the vicinity of a single cusp and result in a universal function for any number of sites of the polygon that can be subtracted away in a systematic manner leaving a well-defined supersymmetric remainder dual to corresponding components of the superamplitude. The question remains though whether components which were free from the aforementioned supersymmetric anomaly at leading order of perturbation theory remain so once computed at higher orders. Presently we verify this fact by calculating a particular component of the null polygonal super Wilson loop at two loops restricting the contour kinematics to a two-dimensional subspace. This allows one to perform all computations in a concise analytical form and trace the pattern of cancellations between individual Feynman graphs in a transparent fashion. As a consequence of our consideration we obtain a dual conformally invariant result for the remainder function in agreement with one-loop NMHV amplitudes.Comment: 14 pages, 3 figure