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[en] A theory recently developed by the authors for slow and fast electrons is shown to be also applicable to channeled ions and to explain the experimental results about electron loss phenomena as a whole. The theory is based on the fundamental hypothesis of the nonadiabaticity of the ion-target interactions. How essential an exponential form of the interaction pseudo-potential is in explaining the energy exchange mechanism at the walls may be deduced from a quasi-classical development of the quantum model. The theory also allows a number of new experiments to be envisaged in the field of surface electron states
[fr]On montre qu'une theorie recemment developpee par les auteurs pour les electrons lents et pour les electrons rapides s'applique egalement aux ions canalises et permet de rendre compte de l'ensemble des resultats experimentaux concernant, les phenomenes des pertes electroniques. La theorie est basee sur l'hypothese fondamentale de non adiabaticite des interactions ion-cible. Un traitement quasi-classique du modele quantique permet de comprendre pourquoi une forme exponentielle pour le pseudo-potentiel d'interaction est essentielle pour expliquer le mecanisme des echanges energetiques au niveau des parois. Cette theorie permet egalement de prevoir un certain nombre d'experiences nouvelles dans le domaine des etats electroniques de surface
[en] Complete text of publication follows. Long term observations of loss of relativistic electrons to the atmosphere is presented and related to SW parameters. It is shown that the L-region of relativistic electron losses match the anisotropic proton zone. In this zone the pitch angle distribution of the protons are unstable and can generate/amplify EMIC waves, which in turn scatter the electrons into the atmosphere. In spatial limited regions, located close to the plasma pause, there can be enhanced losses of protons (sometime completely filling the loss cone). These regions of proton losses (spikes) are shown to give rise to EMIC waves leading to enhance scattering of the relativistic electrons. In the main phase of the storm the proton spikes are located in the midnight/evening sector, but in the storm recovery phase they are located at all MLTs. Proton spikes are observed in all storms, but loss of relativistic electrons only takes place in some storms.
[en] The electrochemical behavior of the flavonoids hesperidin, quercetin, naringin, rutin, catechin, epicatechin and caffeic acid at the mercury electrode (HMDE, DME) and at a glassy carbon electrode has been studied by differential pulse polarography. Determination of flavonoids can be achieved either by direct reduction of the carbonyl group in the gamma-pyron ring, indirectly by cathodic stripping voltammetry via the formation of different flavonoid-mercury complexes at the mercury electrode surface and by adsorptive stripping voltammetry via the direct oxidation of aromatic o-dihydroxy groups. The advantage of stripping voltammetry is higher sensitivity and due to the possibility of higher sample dilution less influence of matrix effects. The application by cathodic stripping voltammetry to the determination of hesperidin in orange juice, hesperidin and rutin in helopyrin(R) tablets, a phytopharmaceutical preparation, naringin in grapefruit juice is demonstrated. Also the application by adsorptive stripping voltammetry at a glassy carbon electrode to the determination of quercetin in blood and sinupret, a phytopharmaceutical preparation and catechin in beer is demonstrated. Both methods are suitable for the determination of low flavonoid concentrations down to the ppb concentration range. (author)
[en] Molybdenum is separated from molybdenum-containing activated charcoal or char also containing small amounts of uranium obtained as a by-product in uranium leaching processes by stripping with an alkaline solution to provide a molybdenum-containing solution containing substantially less than 500 ppm U3O8
[en] Tritium differs from the other hydrogen isotopes in that the beta decay energy produces a steady-state ion population in the gas. Thus, reactions occur in the presence of tritium that are hard to duplicate in other circumstances. The beta particle with average energy produces 155 ion pairs before becoming thermalized. Studies has shown that near 800 K T3+ is the prevailing positive ion. As the temperature is lowered, T3+ combines with T2 to produce T5+, which becomes dominant near 200 K. In the paper the authors consider T3+ to be the only cluster ion present
[en] A review will be presented on recent investigations concerning the interaction of slow (≤ 106 m/s) ions in high charge states approaching a clean metal surface. Detailed information on the generation and decay of transiently formed multiply excited open-quotes hollow atomsclose quotes can be gained from the measurement of total yields and energy distributions of emitted electrons and, in particular, from the electron emission statistics. By comparing measured results with model calculations based on a recently extended classical over-barrier approach, different sources for the observed electron emission can be identified: autoionisation of the multiply excited hollow atoms on their way toward the surface; promotion above the vacuum barrier of electrons previously captured by the projectile, due to their self- and image-charge screening near the surface; 'peeling-off' of electrons still bound in highly excited projectile states at the moment of surface impact, and finally; electron emission due to final subsurface de-excitation
[en] Complete text of publication follows. Recent observations show that the decay rate of relativistic electrons measured at low altitudes in the slot region at L=2 is an order of magnitude shorter than theoretical estimates based on CRRES wave data. Here we compare the decay rates of 2-6 MeV electrons measured at low altitudes by the SAMPEX spacecraft with those derived from CRRES wave observations. We show that pitch angle scattering by plasmaspheric hiss (0.1 < f < 2 kHz) is the dominant process responsible for electron loss in the outer slot region (2.4 < L < 3.0), but hiss alone cannot account for the observed loss timescales at lower L. Although SAMPEX samples small equatorial pitch angles (αeq ∼ 18 deg), this is not the dominant reason for the different timescales. We find that the decay of 2-6 MeV electrons measured by SAMPEX in the inner slot region (2.0 < L < 2.4) is most likely due to the combined effects of hiss and guided whistlers propagating with small wave normal angles. Unguided whistlers have little or no effect on the loss timescales. Magnetosonic waves may be as important as guided whistlers for electron loss under active conditions. Guided whistlers, and fast magnetosonic waves, increase the diffusion rates in a 'bottleneck region' near αeq = 75 deg enabling electrons with larger pitch angles to diffuse into the loss cone more effectively and hence the entire distribution function decays more rapidly. Even though the power of guided whistlers and magnetosonic waves may be two orders of magnitude less than hiss, they play a very important role in electron loss in the inner slot region.
[en] The top value of power enhancement and voltage multiplication in inductive store system with the plasma opening switch (POS) have been studied. Different kinds of loads have been considered. It has been shown that electron losses in vacuum transmission line (VTL) with self-magnetic insulation (SMI) can essentially change the output pulse parameters. Among issues examined are also the effects of the POS on synchronization condition of the multimodule generator and on the optimum linear parameters used at Angara-5 facility
[en] We discuss two different approaches for the approximate treatment of the bremsstrahlung (BrS) process of non-relativistic electrons on many-electron atomic/ionic targets, described by a total amplitude which is a sum of ordinary and polarizational BrS amplitudes. The approaches are based on the so-called 'stripping' effect; they are useful for calculation of the BrS spectra for photon energies greater than the outer shell thresholds. (author)