1,514 research outputs found
Preparation and characterization of Bi26β2xMn2xMo10O69-d and Bi26.4Mn0.6Mo10β2yMe2yO69-d(Me = V, Fe) solid solutions
Received: 06.06.2017; accepted: 23.06.2017; published: 14.07.2017.Single phase samples of bismuth molybdate, Bi26Mo10O69, doped with Mn on the bismuth sublattice and V, Fe on the molybdenum sublattice were found to crystallize in the triclinic Bi26Mo10O69 structure at low doping levels and in the monoclinic Bi26Mo10O69 structure - at higher dopant concentration. The assumption that all Mn ions have an oxidation state of +2 was confirmed by means of magnetic measurement results analysis using Curie-Weiss law. Conductivity was investigated using impedance spectroscopy. The conductivity of Bi26.4Mn0.6Mo9.6Fe0.4O69-d was 1.2*10-2 S*cm-1 at 973 K and 2.2*10-4 S*cm-1 at 623 K, and the conductivity of Bi26.4Mn0.6Mo9.2V0.8O69-d was 2.2*10-3 S*cm-1 at 973 K and 2.2*10-5 S*cm-1 at 623 K
Peculiar behavior of the electrical resistivity of MnSi at the ferromagnetic phase transition
The electrical resistivity of a single crystal of MnSi was measured across
its ferromagnetic phase transition line at ambient and high pressures. Sharp
peaks of the temperature coefficient of resistivity characterize the transition
line. Analysis of these data shows that at pressures to ~0.35 GPa these peaks
have fine structure, revealing a shoulder at ~ 0.5 K above the peak. It is
symptomatic that this structure disappears at pressures higher than ~0.35 GPa,
which was identified earlier as a tricritical poin
The differentiated assessment of damage to economy of subjects of the Siberian Federal District from road and transport accident rate
The results of assessment of damage from the road accident rate in subjects of the Siberian Federal District (SFD) of the Russian Federation are presented in the article. The thesis about spatial differentiation of the Gross Regional Product (GRP) losses in different regions of the country because of people's death and injuries in the road accidents (RA) and due to formations of property and ecological damage was chosen as a working hypothesis. The calculations, carried out for 12 subjects of the SFD, confirmed this idea. The range of calculated values of economic damage from road accident rate (in % of GRP) was from 1.3 (Tomsk region) to 12.6 (Republic of Tyva) in 2015. In article the attempt to explain the received result by heterogeneous development of economics in various Russian regions is made. The consequence of it is a heterogeneous quality of people's life and quite various perception of life value by inhabitants of different regions that influences their life safety level. Β© 2018 Institute of Physics Publishing. All rights reserved
A Pulsational Model for the Orthogonal Polarization Modes in Radio Pulsars
In an earlier paper, we introduced a model for pulsars in which non-radial
oscillations of high spherical degree (\el) aligned to the magnetic axis of a
spinning neutron star were able to reproduce subpulses like those observed in
single-pulse measurements of pulsar intensity. The model did not address
polarization, which is an integral part of pulsar emission. Observations show
that many pulsars emit radio waves that appear to be the superposition of two
linearly polarized emission modes with orthogonal polarization angles. In this
paper, we extend our model to incorporate linear polarization. As before, we
propose that pulsational displacements of stellar material modulate the pulsar
emission, but now we apply this modulation to a linearly-polarized mode of
emission, as might be produced by curvature radiation. We further introduce a
second polarization mode, orthogonal to the first, that is modulated by
pulsational velocities. We combine these modes in superposition to model the
observed Stokes parameters in radio pulsars.Comment: 19 pages, 4 figures accepted Ap
ΠΡΠ΅ΠΊΡΠΎΡ Π½Π° Π²Π°Π»ΠΏΡΠΎΠ°Ρ Π½Π° ΠΊΠΎΡΡΠΈΠΊΠ°Π»Π½Π°ΡΠ° Π΅Π»Π΅ΠΊΡΡΠΎΠ³Π΅Π½Π΅Π·Π°
ΠΠ° ΠΏΠΎΠΊΠ°ΠΆΠ΅ΠΌΠ΅ Π½Π΅ΠΊΠΎΠΈ Π½Π°ΡΠΈ ΠΊΠ»ΠΈΠ½ΠΈΡΠΊΠΈ ΠΈΡΠΊΡΡΡΠ²Π° Π·Π° Π΅ΡΠ΅ΠΊΡΠΎΡ Π½Π° Ρ
ΡΠΎΠ½ΠΈΡΠ½ΠΈΠΎΡ ΡΡΠ΅ΡΠΌΠ°Π½ ΡΠΎ Π²Π°Π»ΠΏΡΠΎΡ Π½Π° ΠΊΠΎΡΡΠΈΠΊΠ°Π»Π½Π°ΡΠ° Π΅Π»Π΅ΠΊΡΡΠΎΠ³Π΅Π½Π΅Π·Π°, ΠΊΠΎΠ΅ Π΄ΠΎΡΠ΅Π³Π° ΠΌΠ½ΠΎΠ³Ρ ΠΌΠ°Π»ΠΊΡ Π΅ ΡΡΡΠ΄ΠΈΡΠ°Π½ΠΎ ΠΈΠ°ΠΊΠΎ Π»Π΅ΠΊΠΎΡ Π΅ Π²ΠΎ ΡΠΏΠΎΡΡΠ΅Π±Π° ΠΎΠ΄ 1964 Π³ΠΎΠ΄ΠΈΠ½Π°
Elastic properties of FeSi
Measurements of the sound velocities in a single crystal of FeSi were
performed in the temperature range 4-300 K. Elastic constants and
deviate from a quasiharmonic behavior at high temperature; whereas,
increases anomalously in the entire range of temperature, indicating a
change in the electron structure of this materia
Application of the Financial Industry Business Ontology (FIBO) for development of a financial organization ontology
The article considers an approach to a formalized description and meaning harmonization for financial terms and means of semantic modeling. Ontologies for the semantic models are described with the help of special languages developed for the Semantic Web. Results of FIBO application to solution of different tasks in the Russian financial sector are given
Method for optimizing the shell of open pit mines based on parallel computing
One of the main stages in design of mineral development process is solution of finding optimal open pit problem. It is necessary to take into account the spatial distribution of mineral components and the allowable slope angles of the sides during solving this problem. The basis for performing calculations to optimize the extraction of reserves is a digital block model of the mineral deposit. The larger and more accurate block model of the ore deposit requires more computationally complex calculation process. In this regard, using of parallel computing in this area is very relevant. The importance of solving this problem determined by the need to have an accurate model of the open pit at various stages of its developmen
Giant Pulses with Nanosecond Time Resolution detected from the Crab Pulsar at 8.5 and 15.1 GHz
We present a study of shape, spectra and polarization properties of giant
pulses (GPs) from the Crab pulsar at the very high frequencies of 8.5 and 15.1
GHz. Studies at 15.1 GHz were performed for the first time. Observations were
conducted with the 100-m radio telescope in Effelsberg in Oct-Nov 2007 at the
frequencies of 8.5 and 15.1 GHz as part of an extensive campaign of
multi-station multi-frequency observations of the Crab pulsar. A selection of
the strongest pulses was recorded with a new data acquisition system, based on
a fast digital oscilloscope, providing nanosecond time resolution in two
polarizations in a bandwidth of about 500 MHz. We analyzed the pulse shapes,
polarisation and dynamic spectra of GPs as well as the cross-correlations
between their LHC and RHC signals. No events were detected outside main pulse
and interpulse windows. GP properties were found to be very different for GPs
emitted at longitudes of the main pulse and the interpulse. Cross-correlations
of the LHC and RHC signals show regular patterns in the frequency domain for
the main pulse, but these are missing for the interpulse GPs. We consider
consequences of application of the rotating vector model to explain the
apparent smooth variation in the position angle of linear polarization for main
pulse GPs.
We also introduce a new scenario of GP generation as a direct consequence of
the polar cap discharge. We find further evidence for strong nano-shot
discharges in the magnetosphere of the Crab pulsar. The repetitive frequency
spectrum seen in GPs at the main pulse phase is interpreted as a diffraction
pattern of regular structures in the emission region. The interpulse GPs
however have a spectrum that resembles that of amplitude modulated noise.
Propagation effects may be the cause of the differences.Comment: Astronomy & Astrophysics (accepted
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