High-resolution, high signal-to-noise ratio spectra have been obtained for 32 metal-poor stars. The equivalent widths of Li λ6708A were measured and the lithiu
<正>We study the magnetic structure of five well-known active regions that produced great flares (X5 or larger). The six flares under investigation are the X12
We analyze the spectral line broadening of those magneto-sensitive lines in solar magnetized atmospheres. The broadening at the line wings is due to the increas