Optical Conductivity of Clean Metals

We briefly review some basic aspects of transport in clean metals focusing on the role of electron-electron interactions and neglecting the effects of impurities, phonons and interband transitions. Both for small Fermi surfaces of two and three-dimensional metals and open Fermi surfaces of quasi one-dimensional metals the dc conductivity sigma is largely dominated by momentum and pseudo-momentum conservation, respectively. In general, the frequency and temperature dependencies of sigma(w,T) have very little in common. For small Fermi surfaces in three dimensions we find for example that the scattering rate is quadratic in frequency, Gamma \propto w^2, even in the absence of a T^2 contribution.Comment: invited paper for a special edition of Annalen der Physik commemorating P. Drud

Reflections on diversity linguistics: Language inventories and atlases

This contribution gives a short overview of “language inventorying”: research aiming at creating comprehensive catalogues and atlases of all the languages in the world, which has seen a boost with the renewed interest in linguistic diversity triggered by the awareness of language endangerment in the 1990s. By focusing on the development of the ISO standard 639 and SIL’s Ethnologue, the main advances and issues in this area are discussed. The overview concludes by presenting the major alternative resources, in particular Glottolog.National Foreign Language Resource Cente

Konzert für Klavier und Orchester

Sein Konzert für Klavier und Orchester komponierte Matthias Drude während seines Kompositionsstudiums in Hamburg bei Ulrich Leyendecker 1985-86. Es lässt neben zahlreichen Vorbildern bereits Ansätze eines eigenen Stils erkennen. Das zweisätzige, knapp 20-minütige Werk wurde noch nicht aufgeführt. 2018 hat es der Komponist revidiert und in Computer-Notensatz (SIBELIUS) übertragen.:1. Moderato - Allegro ... Seite 1 2. Variationen ... Seite 3

Exact expression for Drude conductivity in one-dimension with an arbitrary potential

An exact expression for the Drude conductivity in one dimension is derived under the presence of an arbitrary potential. In getting the conductivity the influence of the electric field on the crystal potential is taken into account. This coupling leads to a systematic deformation of the potential and consequently to a significant modification of the charge transport. The corrections to the conventional Drude conductivity are determined by the configurational part of the partition function. The activation energy for the conductivity process is expressed by a combination of the free energy of the underlying equilibrium system. The electric current is calculated in the linear response regime by solving the Smoluchowski equation. The steady state solution differs significantly from the equilibrium distribution. In case of a tight binding potential the conductivity offers corrections depending on the amplitude of the potential. As a further application we discuss nanocontacts with piecewise constant potentials. The electric conductivity is corrected by the potential height.Comment: 12 pages, 3 figure

Expedições alemães que fundaram a etnologia da Amazônia

Resenhas: KRAUS, Michael. Bildungsbürger im Urwald: Die deutsche ethnologische Amazonienforschung (1884–1929). Marburg: Curupira, 2004. 539 p.: il. ISBN 3-8185-0397-4.Rezension zu: KRAUS, Michael. Bildungsbürger im Urwald: Die deutsche ethnologische Amazonienforschung (1884–1929). Marburg: Curupira, 2004. 539 p.: il. ISBN 3-8185-0397-4

On the position of the Awetí language in the Tupí family

Conclusion In this study we have examined the evidence for the exact genetic position of the Awetí language in the large Tupí family, especially evidence for an internal classification of the larger branch of Tupí called “Mawetí-Guaraní” which comprises the Tupí-Guaraní family, Awetí and Sateré-Mawé. As it turns out, we did not find any clear example of an uncommon sound change which would have happened after the separation of the antecessor of one branch but before the split between the other two. There is some just probability that Awetí belongs somewhat closer to Tupí-Guaraní within Mawetí-Guaraní (configuration A in Table 1), but we did not find any conclusive evidence. All we have are some weak indications the majority of which, however, point in this direction: • a higher number of cognates found between Awetí and proto-Tupí-Guarani; • lexicostatistic results (number of cognates in a 100-item-word-list proposed by Swadesh); • loss of long vowels in Awetí and Tupí-Guaraní, but not in Sateré-Mawé; • some sound changes suggest that in the development to Awetí and to proto-Tupí-Guaraní velar segments changes to dental segments (cf. the discussion of the correspondence set j : t : w); • possibly some of the correspondence sets given in Table 20. We consider it to be too soon to conclude that there is a branch Awetí + Tupí-Guaraní of Mawetí-Guaraní, opposed to Sateré-Mawé, but if there is any grouping, this hypothesis is most promising. 2

Word accent and its manifestation in Awetí

This paper describes the distribution and phonetic properties of accentuation of word forms in Awetí, a Tupian language spoken by ca. 150 people in central Brazil in the Upper Xingu area. Awetí does not belong to, but is arguably the closest relative of the better known Tupí-Guaraní subfamily, the largest branch of the Tupí stock. After a short overview over the word classes and general phonotactics of Awetí (sec-tion 2), we briefly discuss the notion ‘word accent’ and show that, in Awetí, it is generally located on the last syllable of the stem in morphologically simple forms (section 3). We then discuss regular and isolated exceptions to this rule (section 4). In section 5, we describe the distribution of the word accent when inflectional or deriva-tional suffixes are present – usually, the word accent of the word form with suffixes continues to be on the last syllable of the stem. After this descriptive part, we present a preliminary study of the acoustic-phonetic details of the manifestation of the word accent, observing word forms in isolation (section 6) and in different syntactic con-texts (section 7). The results are briefly summarized in the conclusion (section 8