Zn location in the W‐type hexagonal ferrite SrZnCoFe16O27

The title compound, SrZnCoFe₁₆O₂₇ (ZnCo‐W), strontium zinc cobalt hexadecairon oxide, crystallizes in space group P6₃/mmc, with the Sr atom at a site with symmetry and Zn²⁺ located at two tetrahedral sites (4e and 4f, each with 3m symmetry) of the spinel blocks. The Zn occupancy is 36% on equipoint 4e and 14% on 4f. The enrichment of diamagnetic ions on one of seven sublattices is thought to be responsible for the high temperature dependence of the saturation magnetization.     

Methanol – die Basischemikalie

Today methanol is produced from synthesis gas derived from coal and natural gas. However carbon dioxide and hydrogen obtained from water electrolysis with renewable energy have the potential to play a leading role as fuel, energy raw material and chemical feedstock. As a liquid energy storage system it can be used to easily transport electric power conserved in chemical bonds with unparalleled efficiency. Homologisation making use of the Mobil zeolite processes (MTG, MTO, MTA) for instance, or via the methanol derived platform chemicals methyl formate and dimethyl ether, the majority of organic chemicals established in chemical industry is available. Through its diverse of applications methanol has the potential to substitute crude oil and natural gas as the leading feedstock for organic chemicals.     

High-performance liquid chromatography of lactose with evaporative light scattering detection, applied to determine fine particle dose of carrier in dry powder inhalation products

A method for quantification of the fine particle dose of lactose is described, using a hydrophilic interaction chromatography (HILIC) method and evaporative light scattering detection. The HILIC method used an aminopropyl column and a mobile phase consisting of acetonitril/water (80/20, v/v) for isocratic elution. Sensitive chromatography was obtained using a low concentration of water in the extraction solvent. The detection limit (RSD<10%) at an injection volume of 10 microL is 10 microg/mL. Linearity was obtained in the range of 10-80 microg/mL (R(2)>0.99). A relative standard deviation (RSD) of 0.5% (N=6) demonstrated good precision of the optimized method.     

Spin polarization in low-energy electron diffraction: Surface analysis of Pt(111)

Transverse and longitudinal spin polarization components arising in the diffraction of unpolarized low-energy electrons from Pt(111) have been studied as functions of energy and diffraction geometry. Experimental data measured by means of a Mott detector are in good agreement with theoretical results obtained by relativistic LEED calculations. A detailed investigation of the selective sensitivity of the calculated polarization profiles to the surface relaxation δ₁₂ and to various non-structural model features firstly supports an ion-core potential involving an energy-dependent exchange approximation (by discriminating against two band structure potentials), and secondly establishes the geometry of Pt(111) as unreconstructed with a possible slight outward relaxation of the topmost atomic layer (δ₁₂ = 0.5% ± 1.0% of the bulk interlayer distance). A surface Debye temperature is found close to the bulk value 230 K.     

On the vibrational linear and nonlinear optical properties of compounds involving noble gas atoms: HXeOXeH,HXeOXeF, and FXeOXeF

The vibrational (hyper)polarizabilities of some selected Xe derivatives are studied in the context of Bishop–Kirtman perturbation theory (BKPT) and numerical finite field methodology. It was found that for this set of rare gas compounds, the static vibrational properties are quite large, in comparison to the corresponding electronic ones, especially those of the second hyperpolarizability. This also holds for the dc‐Pockels β(?ω;ω,0), Kerr γ(?ω;ω,0,0) and electric field second harmonic generation γ (?2ω;ω,ω,0) effects, although the computed nuclear relaxation (nr) vibrational contributions are smaller in magnitude than the static ones. HXeOXeH was used to study the effects of electron correlation, basis set, and geometry. Geometry effects were found to lead to noticeable changes of the vibrational and electronic second hyperpolarizability. A limited study of the effect of Xe insertion to the nr vibrational properties is also reported. Assessment of the results revealed that Xe insertion has a remarkable effect on the nr (hyper)polarizabilities. In terms of the BKPT, this is associated with a remarkable increase of the electrical and mechanical anharmonicity terms. The latter is consistent with the anharmonic character of several vibrational modes reported for rare gas compounds. © 2013 Wiley Periodicals, Inc.