Stability trends and fragmentation patterns of gaseous yttrium oxide clusters studied by fast atom bombardment tandem mass spectrometry

The fragmentation patterns of yttrium oxide cluster species YO+, Y2O2+, Y2O3+, Y3O4+, Y4O6+, Y5O7+, Y6O8+ and Y7O10+ were investigated at collision energies 30-110 and 170 eV by fast atom bombardment tandem mass spectrometry. The collision activated dissociation (CAD) spectra obtained revealed higher thermodynamic stability for the clusters of general formula YαO(3α-1)/2+, where a is an odd number (e.g. YO+, Y3O4+, Y5O7+, Y7O10+) which are also the preferred CAD products for all oxide clusters studied. These most stable oxides are constituted by trivalent yttrium only whereas those containing formally tetravalent yttrium YaO3a/2+, (where a is even) e.g. Y2O3+ and Y4O6+, are extremely unstable. The clusters YaO(3a-2)/2+, (where a is even) containing divalent yttrium, e.g. Y2O2+ and Y6O8+, have considerable stability but their CAD products are again the thermodynamic products YaO(3a-1)/2+. Electronic structures appear to have overriding significance in determining the thermo- dynamic stabilities of the oxide cluster species. © 1988

An On-Chip Detector of Transient Stress Events

Testing and debugging of electrostatic discharge (ESD) or electrical fast transient (EFT) issues in modern electronic systems can be challenging. The following paper describes the design of an on-chip circuit which detects and stores the occurrence of a fast transient stress event at the ESD protection structures in an I/O pad. Measurements and simulations of a test circuit in 90 nm technology show it can accurately detect and record the presence of a transient stress event with a peak current as low as 0.9 A or duration as short as 1 ns and that the detector works well across typical temperature and process variations. The small size of the detector will allow it to be used effectively even in low-cost commercial IC

Higher mortality in patients with right hemispheric intracerebral haemorrhage: INTERACT1 and 2

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