17 research outputs found
On the diel rhythm of motor activity in perch [Translation from: Informatsionnyi Byulleten Biologiya Vnutrennikh Vod No.30, 12-14, 1976]
The river perch (Perca fluviatilis L.) is most active in the daytime hours, and displays seasonal changes of diel rhythm with a break of the rhythm in spring and autumn. In the present work data were obtained on the motor activity of 3 perch measuring l8-20 cm, caught by net in the littoral of a reservoir and spawned under laboratory conditions. The degree of intensity of movement of perch was judged by special experiments. The results are summarised in this short paper
nu=1/2 quantum Hall effect in the Aharonov-Casher geometry in a mesoscopic ring
We study the effect of an electric charge in the middle of a ring of
electrons in a magnetic field such as . In the absence of the
central charge, a residual current should appear due to an Aharanov-Bohm
effect. As the charge varies, periodic currents should appear in the ring. We
evaluate the amplitude of these currents, as well as their period as the
central charge varies. The presence of these currents should be a direct
signature of the existence of a statistical gauge field in the
quantum Hall effect. Numerical diagonalizations for a small number of electrons
on the sphere are also carried out. The numerical results up to 9 electrons are
qualitatively consistent with the mean field picture.Comment: 23 pages,14 included postscript figures, submitted to Phys. Rev.