163 research outputs found
Arrangement of dominant poles localization areas of automatic control interval system in specified truncated sector
Characteristic polynomial of automatic control system has been considered. Its coefficients contain linearly entering interval parameters of control object and regulator adjustable parameters. The technique of determining regulator tunings supporting specified root quality indices of interval system was developed. The numerical illustration is give
Parametric synthesis of linear regulator in interval system with guaranteed root quality indices
Automatic control system containing proportional-plus-integral action regulator and control object which has interval specified parameters has been considered. Using robust expansion of root-locus method the technique of synthesis of proportional-plus-integral action regulator parameters guaranteeing minimal degree of stability and maximal degree of system oscillation was developed. The technique is based on vertex analysis of root quality indices applying the equation of Theodorchik-Evans. The numeric illustration is give
Thermal analysis and electron probe microanalysis of the AK6 aluminum alloy
Processes of melting the samples of industrial AK6 aluminum alloy in cast and homogenized states are studied using thermal analysis with the subsequent numerical differentiation with respect to time of heating curves in a temperature range from 300 to 670Β°C. The temperatures of nonequilibrium solidus, equilibrium solidus, and liquidus are evaluated. The microstructure of cast and homogenized alloy samples is studied and the local chemical composition of the aluminum host and phases is determined. Β© 2013 Allerton Press, Inc
Dialogue state tracking accuracy improvement by distinguishing slot-value pairs and dialogue behaviour
Dialog state tracking (DST) plays a critical role in cycle life of a task-oriented dialogue system. DST represents the goals of the consumer at each step by dialogue and describes such objectives as a conceptual structure comprising slot-value pairs and dialogue actions that specifically improve the performance and effectiveness of dialogue systems. DST faces several challenge
Raman spectroscopy of the low dimensional antiferromagnet with large Neel temperature SrRu2O6
We report results of the Raman measurements for SrRuO having
extraordinary high Nel temperature for a layered material.
No additional phonon modes were detected at the temperature of magnetic
transition thus excluding lowering of the symmetry in the magnetically ordered
phase. An unusual increase in softening and damping of some phonons as the
temperature approaches indicate the appearance of a continuum of
interacting electronic excitations at . We also observe an intensive
Raman response at 2050 cm. Analysis of the polarization dependence and
comparison with available theoretical data shows that this peak likely
originates from the transitions between molecular orbitals previously proposed
to explain the magnetic properties of SrRuO
A Single-Loop DC Motor Control System Design with a Desired Aperiodic Degree of Stability
The application of the original analytical approach for Pi-controller synthesis of a stable second-order plant is considered. This approach allows finding controller parameters without any intensive computing by using the direct expressions. The plant model is obtained on the basis of identification, which is based on the automated real-interpolation method. The results of natural experiments are given
Visible light photoluminescence in TiO2/CdS nanopowders synthesized by sol-gel route: Effect of gel aging time
A series of sol-gel TiO2/CdS, TiO2 powders and coagulated CdS nanoparticles were studied by XRD, HRTEM and Raman spectroscopy to elucidate the effect of low-temperature gel aging time on visible photoluminescence (PL) emission of the TiO2/CdS composites. With an increase in aging time a content of amorphous titania and incorporated CdS nanoparticles decreases in composites. For all composites, visible PL emission includes bands attributed to surface oxygen vacancies and hydroxyl group of TiO2 nanocrystals, as well as yellow-green and red bands related to lattice defect states of CdS nanoparticles. It was found that gel aging time is a crucial parameter to influence visible PL emission in composites. This emission is suppressed with increasing aging time, and its evolution shows that healing of oxygen vacancy defects and hydroxyl group affect visible emission more significantly than improving crystallinity degree. The correlation between visible PL emission in TiO2/CdS and their visible-light photocatalytic activity was discussed. Β© 2020, ITMO University. All rights reserved.The research was carried out in accordance with the state assignment for ISSC UB RAS and financial support from ISSC UB RAS (theme AAAA-A19-119031890025-9). TEM study was supported by RFBR (grant No. 20-02-00906). The authors are grateful to Dr. Kozhevnikova N. S. and Dr. Gorbunova T. I. for the provided samples TiO2/CdS and CdS
Resource efficiency development program of National Research Tomsk Polytechnic University
Luminescence in anion-deficient hafnia nanotubes
Hafnia-based nanostructures and other high-k dielectrics are promising
wide-gap materials for developing new opto- and nanoelectronics devices. They
possess a unique combination of physical and chemical properties such as
insensitivity to electrical and optical degradation, radiation damage
stability, a high specific surface area, and an increased concentration of the
appropriate active electron-hole centers. The present paper aims to investigate
the structural, optical, and luminescent properties of anodized
non-stoichiometric nanotubes. As-grown amorphous hafnia nanotubes and
nanotubes annealed at 700{\deg}C with a monoclinic crystal lattice served as
samples. It has been shown that the bandgap for direct allowed
transitions amounts to eV for amorphous and eV for
monoclinic nanotubes. For the first time, we have studied the features of the
intrinsic cathodoluminescence and photoluminescence of the obtained nanotubular
structures with an atomic deficiency in the anion sublattice at
temperatures of 10 and 300 K. A broad emission band with a maximum of 2.3-2.4
eV has been revealed. We have also conducted an analysis of the kinetic
dependencies of the observed photoluminescence for synthesized samples
in the millisecond range at room temperature. It showed that there are several
types of optically active capture and emission centers based on vacancy states
in the and positions with different coordination numbers and
a varied number of localized charge carriers (, , and ). The
uncovered regularities can be used to optimize the functional characteristics
of developed-surface luminescent media based on nanotubular and nanoporous
modifications of hafnia.Comment: 15 pages, 6 figures, 3 tables, 50 reference
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