Source Apportionment for the Zinc—Containing Component of Air Particulate Matter using Automated Electron Probe Micro Analysis of Individual Particles

Abstract

A methodology is described for the apportionment of zinc-containing particulate matter sampled in the vicinity of a zinc smelter to their corresponding sources in the factory. Bulk samples of particulate matter from six potential emission sources were analysed by automated electron probe microanalysis (EPMA) in order to characterize the individual particles. Based on a data set of relative peak intensities and with the aid of a binary clustering method, the most important particle classes were identified. They were used as a basis for the development of a set of disjunct identification rules (decision rules), which were able to describe the classes in a unique manner. Applying these rules upon ambient particulate data enabled the estimation of relative contributions of different types of zinc-containing particles. Evidence was found that a large number of particles was modified by a soil component or by gas phase reactions.     

FeIII Quinolylsalicylaldimine Complexes: A Rare Mixed‐Spin‐State Complex and Abrupt Spin Crossover

A new synthesis of (8‐quinolyl)‐5‐methoxysalicylaldimine (Hqsal‐5‐OMe) is reported and its crystal structure is presented. Two Fe^III complexes, [Fe(qsal‐5‐OMe)₂]Cl ? solvent (solvent=2 MeOH ? 0.5 H₂O ( 1 ) and MeCN ? H₂O ( 2 )) have been prepared and their structural, electronic and magnetic properties studied. [Fe(qsal‐5‐OMe)₂] Cl ? 2 MeOH ? 0.5 H₂O ( 1 ) exhibits rare crystallographically independent high‐spin and low‐spin Fe^III centres at 150 K, whereas [Fe(qsal‐5‐OMe)₂]Cl ? MeCN ? H₂O ( 2 ) is low spin at 100 K. In both structures there are extensive π–π and C? H???π interactions. SQUID magnetometry of 2 reveals an unusual abrupt stepped‐spin crossover with T_1/2=245 K and 275 K for steps 1 and 2, respectively, with a slight hysteresis of 5 K in the first step and a plateau of 15 K between the steps. In contrast, 1 is found to undergo an abrupt half‐spin crossover also with a hysteresis of 10 K. The two compounds are the first Fe^III complexes of a substituted qsal ligand to exhibit abrupt spin crossover. These conclusions are supported by ⁵⁷Fe Mössbauer spectroscopy. Both complexes exhibit reversible reduction to Fe^II at ?0.18 V and irreversible oxidation of the coordinated qsal‐5‐OMe ligand at +1.10 V.     

Giant viscosity enhancement in a spin-polarized fermi liquid

The viscosity is measured for a Fermi liquid, a dilute 3He-4He mixture, under extremely high magnetic field/temperature conditions (Bor=1.5 mK). The spin-splitting energy microB is substantially greater than the Fermi energy kBTF; as a consequence the polarization tends to unity and s-wave quasiparticle scattering is suppressed for T相似文献   

Towards a microchannel‐based X‐ray detector with two‐dimensional spatial and time resolution and high dynamic range

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Magnetically Aligned Supramolecular Hydrogels

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Development of a Mild and Versatile Directed Cycloaddition Approach to Pyridines

The aza‐Diels–Alder cycloaddition of 1,2,4‐triazines with alkynes offers a rapid and convenient method for the synthesis of highly substituted pyridines, but often requires harsh conditions and long reaction times. The present study offers a solution to these limitations by use of a temporary tether established by a Lewis acid–base complexation of in situ generated alkynylboranes and triazines bearing a Lewis basic donor. The cycloaddition reactions take place within 20 min at 40 °C and provide direct access to a broad range of pyridines with complete and predictable regiocontrol. The carbon?boron bond can be further functionalised by cross‐coupling allowing further functionality to be introduced after cycloaddition.     

Facile CH Bond Formation by Reductive Elimination at a Dinuclear Metal Site

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Aldehyde oxidase assay by capillary electrophoresis: From off‐line,online up to immobilized enzyme reactor

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