4,533 research outputs found
The level of somatic health, sports specialization and qualification of an athlete as indicators of intermediate selection in the mixed martial arts
This article presents the results of experimental research to identify high-priority types of martial arts whose representatives successfully implement their skills in mixed martial arts, as well as the results of the study of somatic healt
Metal-insulator transition and magnetism in correlated band insulator: FeSi and FeCoSi
The LDA+DMFT (local density approximation combined with dynamical mean-field
theory) computation scheme has been used to study spectral and magnetic
properties of FeSi and FeCoSi. Having compared different models
we conclude that a correlated band insulator scenario in contrast to Kondo
insulator model agrees with FeSi band structure as well as experimental data.
Coulomb correlation effects lead to band narrowing of the states near the Fermi
level with mass renormalization parameter in agreement with the
results of angle-resolved photoemission spectroscopy (ARPES). Temperature
dependence of spectral functions and magnetic susceptibility calculated in DMFT
reproduces transition from nonmagnetic semiconductor to metal with local
magnetic moments observed experimentally. Cobalt doping leads to ferromagnetism
that has itinerant nature and can be successfully described by LDA+DMFT method.Comment: 10 pages, 15 figure
Hydrogen isotope exchange in proton-conducting oxides during proton and deuteron irradiation
It has been found that during accelerator beam deuteron irradiation of a proton-conducting oxide containing protium H/D isotope exchange between beam ions and dissolved ions takes place. This isotope exchange was also observed during high-energy proton irradiation of the oxide containing dissolved deuterium atoms. These results provide evidence to a new type of hydrogen isotope exchange. Any appreciable effects of conjugate diffusion of hydrogen and oxygen ions and of the interface processes on the isotope exchange rate were eliminated. In this type of exchange the rate of replacement of H+ by D+ and of D+ by H+ was determined only by the properties of the crystal. The discovered effect was used in our study to obtain experimental data characterizing the dynamic and equilibrium behavior of hydrogen isotopes in the oxide BaZr0.9Y0.1O3 - δ. © 2013 Pleiades Publishing, Ltd
Isomeric states close to doubly magic Sn studied with JYFLTRAP
The double Penning trap mass spectrometer JYFLTRAP has been employed to
measure masses and excitation energies for isomers in Cd,
Cd, Cd and Te, for isomers in In and
In, and for isomers in Sn and Sb. These first
direct mass measurements of the Cd and In isomers reveal deviations to the
excitation energies based on results from beta-decay experiments and yield new
information on neutron- and proton-hole states close to Sn. A new
excitation energy of 144(4) keV has been determined for Cd. A good
agreement with the precisely known excitation energies of Cd,
Sn, and Sb has been found.Comment: 10 pages, 6 figures, submitted to Phys. Rev.
Mass measurements in the vicinity of the doubly-magic waiting point 56Ni
Masses of 56,57Fe, 53Co^m, 53,56Co, 55,56,57Ni, 57,58Cu, and 59,60Zn have
been determined with the JYFLTRAP Penning trap mass spectrometer at IGISOL with
a precision of dm/m \le 3 x 10^{-8}. The QEC values for 53Co, 55Ni, 56Ni, 57Cu,
58Cu, and 59Zn have been measured directly with a typical precision of better
than 0.7 keV and Coulomb displacement energies have been determined. The Q
values for proton captures on 55Co, 56Ni, 58Cu, and 59Cu have been measured
directly. The precision of the proton-capture Q value for 56Ni(p,gamma)57Cu,
Q(p,gamma) = 689.69(51) keV, crucial for astrophysical rp-process calculations,
has been improved by a factor of 37. The excitation energy of the proton
emitting spin-gap isomer 53Co^m has been measured precisely, Ex = 3174.3(10)
keV, and a Coulomb energy difference of 133.9(10) keV for the 19/2- state has
been obtained. Except for 53Co, the mass values have been adjusted within a
network of 17 frequency ratio measurements between 13 nuclides which allowed
also a determination of the reference masses 55Co, 58Ni, and 59Cu.Comment: 14 pages, 13 figures, submitted to Phys. Rev.
Q_EC values of the Superallowed beta-Emitters 10-C, 34-Ar, 38-Ca and 46-V
The Q_EC values of the superallowed beta+ emitters 10-C, 34-Ar, 38-Ca and
46-V have been measured with a Penning-trap mass spectrometer to be 3648.12(8),
6061.83(8), 6612.12(7) and 7052.44(10) keV, respectively. All four values are
substantially improved in precision over previous results.Comment: 9 pages, 7 figures, 5 table
Metal-Insulator Transitions and Magnetism in Correlated Band Insulators: FeSi and Fe1-x CoxSi
The LDA+DMFT (local density approximation combined with dynamical mean-field theory) computation scheme has been used to study spectral and magnetic properties of FeSi and Fe1-x Cox Si. Having compared different models, we conclude that a correlated band insulator scenario in contrast to Kondo insulator model agrees well with FeSi band structure and experimental data. Coulomb correlation effects lead to band narrowing of the states near the Fermi level with mass renormalization parameter m *≈.2 in agreement with the results of angle-resolved photoemission spectroscopy. Temperature dependence of spectral functions and magnetic susceptibility calculated in DMFT reproduces transition from nonmagnetic semiconductor to metal with local magnetic moments observed experimentally. Cobalt doping leads to ferromagnetism that has itinerant nature and can be successfully described by the LDA+DMFT method. © 2010 The American Physical Society.The hospitality of the Institute of Theoretical Physics of Hamburg University (Grant No. SFB 668) and the Institute of Theoretical Physics of ETH-Zurich is gratefully acknowledged. We would like to thank T. M. Rice, M. Sigrist, A. Läuchli, Y. Yamashita, D. van der Marel, and I. Solovyev for helpful discussions, and Y. O. Kvashnin for his assistance with Wannier function analysis. This work is supported by the grant program of President of Russian Federation under Grant No. MK-1162.2009.2, by the scientific program “Development of scientific potential of universities” under Grant No. N 2.1.1/779, by the scientific program of the Russian Federal Agency of Science and Innovation under Grant No. N 02.740.11.0217, President of Russian Federation fund for support for scientific schools under Grants No. NSH 1941.2008.2, No. RFFI 07-02-00041, and No. RFFI-09-02-00431a, grants of the Ural Division of the Russian Academy of Sciences N7 and N28. The calculations were performed on the computer cluster of “University Center of Parallel Computing” of USTU-UPI
Faddeev study of heavy baryon spectroscopy
We investigate the structure of heavy baryons containing a charm or a bottom
quark. We employ a constituent quark model successful in the description of the
baryon-baryon interaction which is consistent with the light baryon spectra. We
solve exactly the three-quark problem by means of the Faddeev method in
momentum space. Heavy baryon spectrum shows a manifest compromise between
perturbative and nonperturbative contributions. The flavor dependence of the
one-gluon exchange is analyzed. We assign quantum numbers to some already
observed resonances and we predict the first radial and orbital excitations of
all states with or 3/2. We combine our results with heavy quark
symmetry and lowest-order SU(3) symmetry breaking to predict the masses and
quantum numbers of six still non-measured ground-state beauty baryons.Comment: 22 pages, 4 figures, 8 tables. Accepted for publication in J. Phys.
- …