69 research outputs found
Cylindrical Two-Dimensional Electron Gas in a Transverse Magnetic Field
We compute the single-particle states of a two-dimensional electron gas
confined to the surface of a cylinder immersed in a magnetic field. The
envelope-function equation has been solved exactly for both an homogeneous and
a periodically modulated magnetic field perpendicular to the cylinder axis. The
nature and energy dispersion of the quantum states reflects the interplay
between different lengthscales, namely, the cylinder diameter, the magnetic
length, and, possibly, the wavelength of the field modulation. We show that a
transverse homogeneous magnetic field drives carrier states from a quasi-2D
(cylindrical) regime to a quasi-1D regime where carriers form channels along
the cylinder surface. Furthermore, a magnetic field which is periodically
modulated along the cylinder axis may confine the carriers to tunnel-coupled
stripes, rings or dots on the cylinder surface, depending on the ratio between
the the field periodicity and the cylinder radius. Results in different regimes
are traced to either incipient Landau levels formation or Aharonov-Bohm
behaviour.Comment: 23 pages, 14 figure
Compressive-decompressive resuscitation with a new device in cardiac patients
The efficacy of compressive-decompressive resuscitation with new device and method in cardiac patients after circulatory arrest was investigated. Comparing to traditional resuscitation methods (Jude J.R., Kouwenhoven W.B., Knickerbocker Y.Y., 1961), efficacy of our original device and methodics was significantly higher. Moreover, it prevented intra-resuscitation traumas of chest osseal components and internal organs
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