Magnetic iron oxide nanopowders produced by CO2 laser evaporation

Magnetic iron oxide nanopowders were produced with the laser evaporation technique under normal process gas pressure. In addition, the generated particles were coated in situ with stearic acid and separated on magnets. The methods and the used laboratory setup are briefly described. Influences of essential process conditions, particularly the use of continuous and pulsed laser radiation as well as the properties of the process gas, were experimentally investigated. The produced nanopowders were analysed with TEM, XRD, and magnetic measurements and confirmed the in-principle suitability of the presented method.     

Relationship between electronic structures and antiplasmodial activities of xanthone derivatives: a 2D-QSAR approach

Structural Chemistry - Malaria is an important disease causing many death in several countries of Africa and Asia. In these continents, some plants such as Garcinia cola are used to fight against...     

Demonstration of the two-chamber approach for high-voltage measurements using collinear laser spectroscopy

An electronic measurement of high-voltages of several ten kV with accuracy as required for precision experiments is currently only feasible using highly sophisticated voltage dividers. Collinear laser spectroscopy can provide a direct and precise measurement of high-voltages using the Doppler shift of accelerated ions. Although proposed already in 1982, a measurement with relative accuracy better than 10^?4 was not reported so far. To improve this accuracy, a dedicated new setup for high-voltage measurements will be installed at the Technische Universität Darmstadt. A two-chamber approach will be used to remove uncertainties due to the insufficiently known starting potential inside the ion source. Here we present a demonstration of the pump-and-probe technique performed in preparatory studies at the TRIGA-LASER experiment in Mainz.     

Towards high precision in-trap laser spectroscopy of highly charged ions

The extremely strong fields that exist around the nuclei of few-electron heavy ions drastically change the properties of the electronic system such as energy level spacings, lifetimes and magnetic moments. In turn, the electrons serve as sensitive probes for nuclear properties such as size, magnetic moment and spatial distribution of charge and magnetization. The energies of their forbidden fine and hyperfine structure transitions strongly depend on the nuclear charge and shift from microwave domains in or close to the optical domain. Thus, they become accessible for laser spectroscopy and its potentially high precision. A number of such measurements have been performed in storage rings and electron beam ion traps, and have yielded results with relative accuracies in the permille region. We present here an experiment under development at GSI Darmstadt which aims to significantly increase the accuracy by employing charged particle traps which allow to slow the ion motion nearly to rest, thus reducing Doppler effects and increasing the possible accuracy to the more than ppm region.     

The orders of singular stresses at plane bi- and trimaterial junctions - Closed-form analytical solutions

The plane problem of a bi- or trimaterial-junction, consisting of dissimilar, homogeneous, isotropic and linear elastic sectors is considered. The asymptotic behaviour of the stresses of this composite situation is analyzed by the complex variable method, based on an appropriate choice of the Kolosov-potentials which are applicable in the vicinity of the vertex. In the analyses, the identification of the singularity exponent is emphasized. With the help of a novel approach it is demonstrated how to derive some solutions for the orders of the stress singularities at bi- and trimaterial combinations in a closed-form analytical manner. (© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

ChemInform Abstract: Structure,Magnetic and Electrical Properties of CeIrSb and Its Hydride CeIrSbH0.8.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.