Spin-Orbit Coupling and Anomalous Angular-Dependent Magnetoresistance in the Quantum Transport Regime of PbS

We measured magnetotransport properties of PbS single crystals which exhibit the quantum linear magnetoresistance (MR) as well as the static skin effect that creates a surface layer of additional conductivity. The Shubnikov-de Haas oscillations in the longitudinal MR signify the peculiar role of spin-orbit coupling. In the angular-dependent MR, sharp peaks are observed when the magnetic field is slightly inclined from the longitudinal configuration, which is totally unexpected for a system with nearly spherical Fermi surface and points to an intricate interplay between the spin-orbit coupling and the conducting surface layer in the quantum transport regime.Comment: 5 pages, 5 figure

The UK Council for Computing Development

SUMMARY If developing countries lack expertise in the utilisation of computers, some developed countries such as the UK may be able to provide aid in this sector. The UK Council for Development, consisting of representatives from academia, government and industry, was set up for this reason. This article offers a statement of its views, its aims and its intent. RESUME Cours britannique de développement informatique Si les pays en développement n'ont pas de compétences en matière d'informatique, certains pays développés tels que la G.B. pourraient leur apporter une aide. Le Conseil britannique du développement, qui regroupe des universitaires, des fonctionnaires et des industriels, a été créé pour cette raison. Cet article présente ses vues, ses objectifs et ses intensions. RESUMEN El curso de la Gran Bretaña para el desarrollo computarizado Si los países en vías de desarrollo carecen de pericia en la utilización de computadoras, algunos países desarrollados tales como la Gran Bretaña pueden proporcionar ayuda en este sector. El Consejo Británico para el Desarrollo, compuesto de representantes del mundo académico, el gobierno y la industria, se estableció con este motivo. En este artículo se presenta una declaración de sus opiniones, sus propósitos y sus intenciones

Quasi-tracking solar active regimes with radio telescope ratan-600 and the construction of two-dimensional radio maps of the sun

We discuss the results of the radio telescope RATAN-600 by “zoned relay” using the conical secondary reflector. Such observations permit the evolution of the radio emission of local solar sources to be studied as well as the construction of the two-dimensional images of the Sun

Comment on "CAWSES November 7-8, 2004, superstorm: Complex solar and interplanetary features in the post-solar maximum phase" by B. T. Tsurutani, E. Echer, F. L. Guarnieri, and J. U. Kozyra

Recently Tsurutani et al., (2008) (Paper 1) analyzed the complex interplanetary structures during 7 to 8 November, 2004 to identify their properties as well as resultant geomagnetic effects and the solar origins. Besides mentioned paper by Gopalswamy et al., (2006) the solar and interplanetary sources of geomagnetic storm on 7-10 November, 2004 have also been discussed in details in series of other papers. Some conclusions of these works essentially differ from conclusions of the Paper 1 but have not been discussed by authors of Paper 1. In this comment we would like to discuss some of these distinctions.Comment: Submitted for publication in Geophysical Research Letter

3D Structure of Microwave Sources from Solar Rotation Stereoscopy vs Magnetic Extrapolations

We use rotation stereoscopy to estimate the height of a steady-state solar feature relative to the photosphere, based on its apparent motion in the image plane recorded over several days of observation. The stereoscopy algorithm is adapted to work with either one- or two-dimensional data (i.e. from images or from observations that record the projected position of the source along an arbitrary axis). The accuracy of the algorithm is tested on simulated data, and then the algorithm is used to estimate the coronal radio source heights associated with the active region NOAA 10956, based on multifrequency imaging data over 7 days from the Siberian Solar Radio Telescope near 5.7 GHz, the Nobeyama Radio Heliograph at 17 GHz, as well as one-dimensional scans at multiple frequencies spanning the 5.98--15.95 GHz frequency range from the RATAN-600 instrument. The gyroresonance emission mechanism, which is sensitive to the coronal magnetic field strength, is applied to convert the estimated radio source heights at various frequencies, h(f), to information about magnetic field vs. height B(h), and the results are compared to a magnetic field extrapolation derived from photospheric magnetic field observations obtained by Hinode and MDI. We found that the gyroresonant emission comes from the heights exceeding location of the third gyrolayer irrespectively on the magnetic extrapolation method; implications of this finding for the coronal magnetography and coronal plasma physics are discussed.Comment: 26 pages, 13 figures, ApJ accepte