840 research outputs found
To a question on statement of a problem on modelling processes of structurization of foam concretes
Сидоренко Ю. В. К вопросу об постановке задачи о моделировании процессов структурообразования пенобетоно
55Mn NMR and magnetization studies of La0.67Sr0.33MnO3 thin films
55Mn nuclear magnetic resonance and magnetization studies of the series of
La0.67Sr0.33MnO3 thin films have been performed at low temperature. Two
distinct lines were observed, at 322 MHz and 380 MHz, corresponding to two
different phases, the former located at the interface, with localized charges,
and the latter corresponding to the film bulk, with itinerant carriers (as it
was also found in Ca manganite films). The spin-echo amplitude was measured as
a function of a dc magnetic field applied either in the film plane or
perpendicular to it. The field dependence of both the main NMR signal intensity
and frequency shift is quite consistent with that calculated in a simple single
domain model. The best fit to the model shows that magnetization rotation
processes play a dominant role when the applied field exceeds the effective
anisotropy field. Distinctly different magnetic anisotropies are deduced from
the interface NMR signal.Comment: 7 pages, 8 figure
Evaluation of GBT-FPGA for timing and fast control in CBM experiment
Timing and Fast Control (TFC) system for the Compressed Baryonic Matter (CBM) experiment is being developed with focus on low and deterministic data transmission latency. This helps to minimize data corruption in the free-streaming Data Acquisition (DAQ) system during occasional data bursts caused by the expected beam intensity fluctuations. Proven in latency-optimized experimental data transport applications, the GBT-FPGA core is expected to positively contribute to the TFC system performance. In this work, the core has been integrated as the primary communication interface and its effect on transmission latency and quality of time distribution has been evaluated
B\"{a}cklund transformations for the constrained dispersionless hierarchies and dispersionless hierarchies with self-consistent sources
The B\"{a}cklund transformations between the constrained dispersionless KP
hierarchy (cdKPH) and the constrained dispersionless mKP hieararchy (cdmKPH)
and between the dispersionless KP hieararchy with self-consistent sources
(dKPHSCS) and the dispersionless mKP hieararchy with self-consistent sources
(dmKPHSCS) are constructed. The auto-B\"{a}cklund transformations for the
cdmKPH and for the dmKPHSCS are also formulated.Comment: 11 page
Reentrant superconductivity in superconductor/ferromagnetic-alloy bilayers
We studied the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) like state
establishing due to the proximity effect in superconducting Nb/Cu41Ni59
bilayers. Using a special wedge-type deposition technique, series of 20-35
samples could be fabricated by magnetron sputtering during one run. The layer
thickness of only a few nanometers, the composition of the alloy, and the
quality of interfaces were controlled by Rutherford backscattering
spectrometry, high resolution transmission electron microscopy, and Auger
spectroscopy. The magnetic properties of the ferromagnetic alloy layer were
characterized with superconducting quantum interference device (SQUID)
magnetometry. These studies yield precise information about the thickness, and
demonstrate the homogeneity of the alloy composition and magnetic properties
along the sample series. The dependencies of the critical temperature on the Nb
and Cu41Ni59 layer thickness, Tc(dS) and Tc(dF), were investigated for constant
thickness dF of the magnetic alloy layer and dS of the superconducting layer,
respectively. All types of non-monotonic behaviors of Tc versus dF predicted by
the theory could be realized experimentally: from reentrant superconducting
behavior with a broad extinction region to a slight suppression of
superconductivity with a shallow minimum. Even a double extinction of
superconductivity was observed, giving evidence for the multiple reentrant
behavior predicted by theory. All critical temperature curves were fitted with
suitable sets of parameters. Then, Tc(dF) diagrams of a hypothetical F/S/F
spin-switch core structure were calculated using these parameters. Finally,
superconducting spin-switch fabrication issues are discussed in detail in view
of the achieved results.Comment: 34 pages, 9 figure
ON THE ISSUE OF PLANNING SOWING AGRICULTURAL CROPS WITH THE MINIMUM RISK UNDER THE PRESENCE OF VARIOUS AGROCLIMATIC CONDITIONS
The present paper deals with one problem of quantitative controlling the seeding of the sown area by agricultural crops in different agroclimatic conditions. The considered problem is studied from the standpoint of three strategies: from the seeding planning perspective aiming at minimal risk associated with possible unfavourable agroclimatic conditions (a probabilistic approach is used); from the perspective of obtaining the maximum crops sales profit (a deterministic approach is used); from the perspective of obtaining the maximum crops harvest. For the considered problem, mathematical models are constructed (one probabilistic model and two deterministic models, respectively), their analytical solutions are found, and then, using a specific example, the application of the constructed and solved mathematical models is illustrated as well as the obtained numerical results are analysed.
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