389 research outputs found
Mechanisms of arsenic clustering in silicon
A model of arsenic clustering in silicon is proposed and analyzed. The main
feature of the proposed model is the assumption that negatively charged arsenic
complexes play a dominant role in the clustering process. To confirm this
assumption, electron density and concentration of impurity atoms incorporated
into the clusters are calculated as functions of the total arsenic
concentration. A number of the negatively charged clusters incorporating a
point defect and one or more arsenic atoms are investigated. It is shown that
for the doubly negatively charged clusters or for clusters incorporating more
than one arsenic atom the electron density reaches a maximum value and then
monotonically and slowly decreases as total arsenic concentration increases. In
the case of doubly negatively charged cluster incorporating two arsenic atoms,
the calculated electron density agrees well with the experimental data.
Agreement with the experiment confirms the conclusion that two arsenic atoms
participate in the cluster formation. Among all present models, the proposed
model of clustering by formation of doubly negatively charged cluster
incorporating two arsenic atoms gives the best fit to the experimental data and
can be used in simulation of high concentration arsenic diffusion.Comment: 13 pages, 4 figures. Revised and shortened version of the paper has
been published in Phys. Rev. B, Vol.74 (3), art. no. 035205 (2006
The vertex coordinates of the Galaxy's stellar systems according to the Gaia DR3 catalogue
We present the results of determining the coordinates of the vertices of
various stellar systems, the centroids of which are located in the Galactic
plane. To do this, the positions, parallaxes, proper motions, and radial
velocities of red giants and subgiants contained in the ~DR3 catalogue
have been used. When determining the components of the deformation velocity
tensors in local coordinate systems, we found the coordinates of the vertices
of the stellar systems under study. It turned out that there is a complex
dependence of vertex deviations in Galactocentric cylindrical () and Galactic rectangular () coordinates. Based on the approach
proposed in this paper, heliocentric distances to vertices have been determined
for the first time. The results obtained show that in addition to the fact that
the angular coordinates of the Galactic center and the vertices of stellar
systems do not coincide, their heliocentric distances do not coincide as well.
This presumably indicates that there are structures in the Galaxy that
noticeably affect its axisymmetry.Comment: 10 pages, 14 figures, 1 table
Tunable coaxial cavity resonator for linear and nonlinear microwave characterization of superconducting wires
We discuss experimental results obtained using a tunable cylindrical coaxial
cavity constituted by an outer Cu cylinder and an inner Pb-BSCCO wire. We have
used this device for investigating the microwave response of the
superconducting wire, both in the linear and nonlinear regimes. In particular,
by tuning the different modes of the cavity to make them resonant at exactly
harmonic frequencies, we have detected the power emitted by the superconducting
inner wire at the second- and third-harmonic frequency of the driving field.
The results obtained in the nonlinear regime, whether for the microwave surface
impedance or the harmonic emission, are qualitatively accounted for considering
intergrain fluxon dynamics. The use of this kind of device can be of strong
interest to investigate and characterise wires of large dimensions to be used
for implementing superconducting-based microwave devices.Comment: 14 pages, 6 embedded figures, accepted for publication in Supercond.
Sci. Techno
Improving educational process quality in the lessons of natural and mathematical cycle by means of stem-training
Today, the educational process is focused on the development of personal characteristics that meet the requirements of a modern educated person. In this regard, the task of educational institutions is to adopt the educational process to today’s realities. To achieve this goal, STEM education is implemente
Substantiation of the choice of optimal concentrations of active ingredients of the antioxidant composition for fruit treatment before storage
UK: Розроблена антиоксидантна композиція на основі іонолу, диметилсульфоксиду та лецитину,
застосування якої сприятиме подовженню терміну зберігання плодів з мінімальним рівнем що-
добових втрат. Проведеною оптимізацією встановлено, що при зберіганні плодів яблуні та груші концентрація дистинолу повинна бути на рівні 0,041…0,042 %, концентрація лецитину – 2,9 %, при зберіганні плодів сливи відповідно: дистинолу – 0,022 %, лецитину – 3,4 %
The development of radio and 3G based telemetry system for the remote gas accounting and control nodes
In this article we have described the use of vortex and recently developed ultrasonic flowmeters with high dynamic range of 1 to 1500 for industrial applications. Its software and the software of corresponding computing device is able to avoid gas leakage, to minimize energy consumption and to save human resources while maintaining metrological data. Described is the low power consumption that makes it possible to use this ultrasonic flowmeter in hard remote environment without direct management for a period of several month
Uphill diffusion of ultralow-energy boron implants in preamorphized silicon and silicon-on-insulator
Physical modeling of various processes in development of the system for monitoring the concentration of suspended particles in the air
The paper shows the need to develop a system for monitoring the concentration of suspended particles in the atmosphere, ensuring industrial safety at enterprises, facilities and in rooms with high dust content. The main possible consumers of this system are presented. Different measuring techniques of suspended particles and their fractions in the air are described, their advantages and weaknesses are mentione
Additive scaling law for structural organization of chromatin in chicken erythrocyte nuclei
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