Element-specific magnetization dynamics of complex magnetic systems probed by ultrafast magneto-optical spectroscopy

The vision to manipulate and control magnetism with light is driven on the one hand by fundamental questions of direct and indirect photon-spin interactions, and on the other hand by the necessity to cope with ever growing data volumes, requiring radically new approaches on how to write, read and process information. Here, we present two complementary experimental geometries to access the element-specific magnetization dynamics of complex magnetic systems via ultrafast magneto-optical spectroscopy in the extreme ultraviolet spectral range. First, we employ linearly polarized radiation of a free electron laser facility to demonstrate decoupled dynamics of the two sublattices of an FeGd alloy, a prerequisite for all-optical magnetization switching. Second, we use circularly polarized radiation generated in a laboratory-based high harmonic generation setup to show optical inter-site spin transfer in a CoPt alloy, a mechanism which only very recently has been predicted to mediate ultrafast metamagnetic phase transitions. © 2020 by the authors. Licensee MDPI, Basel, Switzerland

Electron population dynamics in resonant non-linear x-ray absorption in nickel at a free-electron laser

Free-electron lasers provide bright, ultrashort, and monochromatic x-ray pulses, enabling novel spectroscopic measurements not only with femtosecond temporal resolution: The high fluence of their x-ray pulses can also easily enter the regime of the non-linear x-ray–matter interaction. Entering this regime necessitates a rigorous analysis and reliable prediction of the relevant non-linear processes for future experiment designs. Here, we show non-linear changes in the L3-edge absorption of metallic nickel thin films, measured with fluences up to 60 J/cm2. We present a simple but predictive rate model that quantitatively describes spectral changes based on the evolution of electronic populations within the pulse duration. Despite its simplicity, the model reaches good agreement with experimental results over more than three orders of magnitude in fluence, while providing a straightforward understanding of the interplay of physical processes driving the non-linear changes. Our findings provide important insights for the design and evaluation of future high-fluence free-electron laser experiments and contribute to the understanding of non-linear electron dynamics in x-ray absorption processes in solids at the femtosecond timescale

E. Archaeological Research: 2. Neolithic Periods

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Archäologie und Archäozoologie

Archéologie et archéozoologie, quelle différence ? Ne font-elles pas toutes deux partie d\u27une « archéologie universelle » ? Les « zoo-archéologues » ne devraient-ils pas essayer eux-mêmes de mieux contribuer à une histoire (zoo-)culturelle ? Le principal objectif pour les archéologues des artefacts comme pour les archéozoologues est de collaborer à une interprétation intégrée des variations qualitatives et quantitatives des spectres de faune à travers l\u27espace et le temps. Ce but doit être atteint en prenant en considération les facteurs écologiques et géographiques, mais aussi les traditions historiques des sociétés préhistoriques. Ces facteurs sociaux étant, à juste titre, de plus en plus intégrés dans les raisonnements archéologiques, ils doivent l\u27être aussi dans ceux des archéozoologues.Archaeology and archaeozoology, what is the difference? Aren\u27t they parts of one common archaeology? Shouldn\u27t "zoo-archaeo-logists" try to do more (zoo-) cultural history themselves? An important task for both groups is, to explain temporal and spatial variation of faunal spectra by integrated interpretation. This should not only be done with ecological and geographical arguments, but also by considering historical traditions of prehistoric societies.</p

Neue Untersuchungen zur absoluten Datierung des Männergrabes und der Siedlung auf dem ältestbandkeramischen Fundplatz Schwanfeld, Ldkr. Schweinfurt, Unterfranken [Supplement]

Abstract: Das bekannte Grab des sogenannten „Jäger / Kriegers“ aus der ältestbandkeramischen Siedlung von Schwanfeld in Unterfranken galt aufgrund seiner Radiocarbondatierung lange als frühester Beleg der Neolithisierung im westlichen Mitteleuropa. Da sich die seinerzeitige Probe inzwischen als kontaminiert erwies, wurden drei neue Messungen an diesem Skelett und weitere Daten aus der Siedlung gemeinsam neu kalibriert und dabei ihre Verlässlichkeit gründlich geprüft. Die Bestattung wurde demnach in der Mitte des 54. Jahrhunderts v. u. Z. angelegt; die Siedlungsaktivitäten lassen sich auf etwa 5370/5350–5250 v. u. Z. eingrenzen. Das Grab eines Kindes in der Längsgrube mit Außengraben 796/797 wurde nach dieser Zeit angelegt, wahrscheinlich erst in der späten Linearbandkeramik. Supplement: Detaillierte Liste der Radiocarbondaten aus Schwanfeld, die in dieser Untersuchung berücksichtigt wurden

Binding of group 15 and group 16 oxides by a concave host containing an isophthalamide unit

A bi-macrocycle with an incorporated isophthalamide substructure was synthesized by double amide formation between an isophthaloyl dichloride and two equivalents of a bis(alkenyloxy)aniline, followed by ring-closing metathesis and hydrogenation. In contrast to many related isophthalamides, the concave host exhibits a better binding for oxides, such as DMSO or pyridine-N-oxide, than for halide anions. A general method for a quick estimation of the strength of binding derived from only a few data points is presented and gives an estimated K ass of pyridine-N-oxide of ca. 40 M−1, NMR titration confirms 25 M−1

Business Chemistry: The successful establishment of an interdisciplinary field

The article presents the development of Business Chemistry at seven German and one Swiss universities. Besides highlighting the course of study in general and it's development, the respective universities present benefits but also specific challenges they had to face when introducing Business Chemistry. Followed by a short introduction of Business Chemistry itself, its development and the status quo, every university presented their individual perspectives on the course of study. Overall, the article should provide our readers with an overview of Business Chemistry and sensitize them for the differences in the study programs, even though the courses of study were developed in ac cordance with all respective universities