21 research outputs found
XML als Quelle von Webseiten
Beschreibung von Möglichkeiten XML-Dokumente mittels XSL-Stylesheets in HTML-Dokumente zu überführen. Das Gewicht liegt auf XSLT, der Transformationssprache für XML-Dokumente.This document offers a description how to transform XML Data to HTML files using XSL. The Transformation part of XSL is focused
Datenbankanbindung an das WWW
Beschreibung der verschiedenen Möglichkeiten Datenbanken im WWW ansprechbar
zu machen. Hierbei wird sowohl auf verschiedene Typen von Datenbanken
als auch deren Anbindungen durch klassisches CGI, Java-Servlets, ASP, PHP
und andere verbreitete Lösungen eingegangen. Das Dokument geht nicht auf
technische Details ein, sondern will eher einen Ãœberblick vermitteln
Der APACHE Web-Server
Thema des Dokuments ist die Konfiguration des Apache Web-Servers ab
Version 1.3. Für die behandelten Themen sind jeweils kurze
Konfigurationsbeispiele beigegeben
Stability and instability of hydromagnetic Taylor–Couette flows
Decades ago S. Lundquist, S. Chandrasekhar, P. H. Roberts and R. J. Tayler first posed questions about the stability of Taylor–Couette flows of conducting material under the influence of large-scale magnetic fields. These and many new questions can now be answered numerically where the nonlinear simulations even provide the instability-induced values of several transport coefficients. The cylindrical containers are axially unbounded and penetrated by magnetic background fields with axial and/or azimuthal components. The influence of the magnetic Prandtl number Pm on the onset of the instabilities is shown to be substantial. The potential flow subject to axial fields becomes unstable against axisymmetric perturbations for a certain supercritical value of the averaged Reynolds number Rm¯=√Re⋅Rm (with Re the Reynolds number of rotation, Rm its magnetic Reynolds number). Rotation profiles as flat as the quasi-Keplerian rotation law scale similarly but only for Pm≫1 while for Pm≪1 the instability instead sets in for supercritical Rm at an optimal value of the magnetic field. Among the considered instabilities of azimuthal fields, those of the Chandrasekhar-type, where the background field and the background flow have identical radial profiles, are particularly interesting. They are unstable against nonaxisymmetric perturbations if at least one of the diffusivities is non-zero. For Pm≪1 the onset of the instability scales with Re while it scales with Rm¯ for Pm≫1. Even superrotation can be destabilized by azimuthal and current-free magnetic fields; this recently discovered nonaxisymmetric instability is of a double-diffusive character, thus excluding Pm=1. It scales with Re for Pm→0 and with Rm for Pm→∞.
The presented results allow the construction of several new experiments with liquid metals as the conducting fluid. Some of them are described here and their results will be discussed together with relevant diversifications of the magnetic instability theory including nonlinear numerical studies of the kinetic and magnetic energies, the azimuthal spectra and the influence of the Hall effect
Handreichung zum XML Workshop
Überlick über XML Standards und Werkzeug