295 research outputs found
Диагностика и терапия синдрома кальциевой недостаточности у Серых Жако (Psittacuse.Erithacus)
NMR in Superfluid A-like Phase of He Confined in Globally Deformed Aerogel in Tilted Magnetic Field
NMR spectra in superfluid A-like phases confined in axially deformed aerogel
in presence of a magnetic field inclined with respect to deformation axis is
considered. The characteristic features of dipole frequency shift in axially
compressed and axially stretched cases are compared. In particular, it is shown
that in axially stretched aerogel environment the stability region of
coherently spin precessing mode is rather narrow due to the U(1)LIM effect.Comment: 8 pages, 2 figure
High-temperature quantum kinetic effect in silicon nanosandwiches
The negative- U impurity stripes confining the edge channels of semiconductor quantum wells are shown to allow the effective cooling inside in the process of the spin-dependent transport, with the reduction of the electron-electron interaction. The aforesaid promotes also the creation of composite bosons and fermions by the capture of single magnetic flux quanta on the edge channels under the conditions of low sheet density of carriers, thus opening new opportunities for the registration of the quantum kinetic phenomena in weak magnetic fields at high-temperatures up to the room temperature. As a certain version noted above we present the first findings of the high temperature de Haas-van Alphen, 300 K, quantum Hall, 77 K, effects as well as quantum conductance staircase in the silicon sandwich structure that represents the ultra-narrow, 2 nm, p-type quantum well (Si-QW) confined by the delta barriers heavily doped with boron on the n-type Si (100) surface
EDEPR of impurity centers embedded in silicon microcavities
We present the first findings of the new electrically-detected EPR (EDEPR)
technique which reveal different shallow and deep centers without using the
external cavity as well as the hf source and recorder, with measuring the only
magnetoresistance of the Si-QW confined by the superconductor delta-barriers.Comment: 7 pages, 7 figure
Spin Transistor and Quantum Spin Hall Effects in CdBxF2-x - p-CdF2 - CdBxF2-x Sandwich Nanostructures
Planar CdBxF2-x - p-CdF2 - CdBxF2-x sandwich nanostructures prepared on the
surface of the n-type CdF2 bulk crystal are studied to register the spin
transistor and quantum spin Hall effects. The current-voltage characteristics
of the ultra-shallow p+-n junctions verify the CdF2 gap, 7.8 eV, and the
quantum subbands of the 2D holes in the p-type CdF2 quantum well confined by
the CdBxF2-x delta-barriers. The temperature and magnetic field dependencies of
the resistance, specific heat and magnetic susceptibility demonstrate the high
temperature superconductor properties for the CdBxF2-x delta-barriers. The
value of the superconductor energy gap, 102.06 meV, determined by the tunneling
spectroscopy method appears to be in a good agreement with the relationship
between the zero-resistance supercurrent in superconductor state and the
conductance in normal state at the energies of the 2D hole subbands. The
results obtained are evidence of the important role of the multiple Andreev
reflections in the creation of the high spin polarization of the 2D holes in
the edged channels of the sandwich device. The high spin hole polarization in
the edged channels is shown to identify the mechanism of the spin transistor
and quantum spin Hall effects induced by varying the top gate voltage, which is
revealed by the first observation of the Hall quantum conductance staircase.Comment: 5 pages, 9 figure
The immune system of athletes of different sports
Purpose : the comparative study of the immunity features of elite athletes of different sports. Material : study involved athletes of the highest mastery level of cyclic and acyclic sports (n = 147, age 18-23 years). Athletes were divided into groups by kinds of sport. Skiers (n = 54), swimmers (n = 23), wrestlers (n = 49), boxers (n = 21). Results : It was determined that athletes of acyclic sports (wrestlers and boxers) had a significant double increase in the level of secretory immunoglobulin IgA. In parallel, the level of immunoglobulins IgG is reduced. The highest indicators of lysosomal activity were recorded in skiers. Boxers, wrestlers, and swimmers had a decrease in the lysosomal activity level. The maximum phagocytic number is determined in wrestlers, and the minimum - in boxers. Conclusions : Comparative study of the immunity features of elite athletes in various sports suggests that there is a strain on the immune status. This condition is especially expressed in acyclic sports athletes (wrestling, boxing). This is due to the loads in the preparation process. The data received allow to confirm the significance of immune protection indicators in monitoring the athletes functional status
Peripheral plasma characteristics in the Uragan-3M torsatron
In the l=3/m=9 Uragan-3M (U-3M) torsatron a hydrogen plasma is produced and heated by RF fields in the Alfvén range of frequencies (ω≤ωci). Peripheral plasma is investigated using two moveable Langmuir probes. Spatial distributions of plasma parameters, Vf, Te and ne in two operating regimes and in three cross-sections are measured. Link between confinement volume and transition layer is shown. RF electric antenna field influence on the probes is discussed.В торсатроне Ураган-3М (У-3М) водородная плазма создается и нагревается ВЧ-полями в области альфвеновских частот (ω≤ωci). Периферийная плазма исследована с помощью двух подвижных ленгмюровских зондов. Пространственные распределения параметров плазмы (Vf, Te и ne) были измерены в двух режимах работы установки в трех полоидальных сечениях. Показано существование связи между областью удержания и переходным слоем. Обсуждается влияние ВЧ-электрического поля антенны на зонд.У торсатроні Ураган-3М (У-3М) воднева плазма створюється та нагрівається ВЧ-полями в області альфвенівських частот (ω≤ωci). Периферійна плазма досліджена за допомогою двох рухомих ленгмюровських зондів. Просторові розподіли параметрів плазми (Vf, Te та ne) були виміряні в двох режимах роботи установки в трьох полоїдальних перерізах. Показано існування зв'язку між областю утримання та перехідним шаром. Обговорюється вплив ВЧ-електричного поля антени на зонд
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