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981.
982.
Z. M. Stadnik P. Griesbach P. Gütlich G. Stroink T. Kohara 《Hyperfine Interactions》1988,41(1):705-708
61Ni Mössbauer measurements have been performed at 4.2 K on spherical Ni particles with an average diameter of 100 and 30 Å, covered with a protective layer of SiO. Their spectra contain a surface component with a significantly reduced hyperfine magnetic field as compared with the field in the bulk. This result confirms recent theoretical predictions. 相似文献
983.
Some consequences of a model whereN=1 supersymmetry is realized nonlinearly are worked out forep-collisions at HERA-energies. The model contains in addition to the standard particles one Goldstone-fermion λ, a neutrino-like Majoranaparticle. The existence of such a particle would be signalled by events with large missing energy and momentum. We present detailed predictions for the following special kinematic regions: (1) events with a tagged small angle electron and a largeE T jet, (2) events with a large angle electron and a small angle tagged exclusive proton, (3) events with a tagged small angle electron and a tagged small angle exclusive proton. We indicate the region in coupling constant and mass of the Goldstone-fermion which can be explored at HERA and compare with the limits obtainable from existing data one + e ? and \(p\bar p\) collisions at high energies. 相似文献
984.
985.
A. Türler H. W. Gäggeler D. T. Jost P. Armbruster W. Brüchle H. Folger F. P. Heßberger S. Hofmann G. Münzenberg V. Ninov M. Schädel K. Sümmerer J. V. Kratz U. Scherer 《Zeitschrift für Physik A Hadrons and Nuclei》1988,331(3):363-364
The isotope254No was produced in the fusion reaction48Ca +208Pb. Using the velocity filter SHIP and radiochemical techniques it was found that the nuclide254No with a half-life of 55 s decays byα, EC, and spontaneous-fission. Deduced partial half-lives are (61±2) s forα-decay, (550 ?160 +370 ) s for EC and [2.2 ?1.0 +2.0 ]×104 s for spontaneous fission. 相似文献
986.
G. Müller 《Applied Physics A: Materials Science & Processing》1988,45(1):41-51
We show that, through the diffusive re-arrangement of Si-H bonds, the a-SiH lattice is able to establish thermal equilibrium between the densities of band tail trapped charge carriers and dangling bond defects. When this equilibrium is disturbed by changes in temperature, carrier injection or illumination, dangling bond defects have to be generated or annealed out via H-diffusion processes. Based on the concept of charge-induced bond breaking, we develop a mathematical formalism for the diffusive re-arrangement of Si-H bonds and show that our formalism can account for a variety of observations that have been made in the context of defect-generation and annealing experiments. 相似文献
987.
I. Miesiąc K. Schügerl J. Szymanowski 《Journal of Radioanalytical and Nuclear Chemistry》1992,163(1):181-191
Potassium leakage was studied in liquid membrane systems containing various emulsifiers and compared with emulsion, stability in the storage test. The effects of various parameters upon emulsion stability and the leakage of standard traces are discussed. The transfer of cations can be caused by emulsion breaking, by transport with the specific carrier and/or with surfactants used as emulsifiers. The latter case becomes especially important when hydrophilic surfactants, e.g. ones containing polyoxyethylene chains, are present in liquid membranes. In systems containing hydrophobic emulsifiers the transfer of potassium is relatively low. In each case considered the effect of emulsifiers upon the transfer of the standard tracer should be checked prior to using the leakage test to characterize emulsion stability. 相似文献
988.
989.
990.
The parton distributions of the nucleon are evaluated dynamically using the assumption that at some low resolution scale the nucleon consists entirely of valence quarks. A simple parametrization of the resulting gluon distribution is presented, forx? 10?5 up toQ 2?106 GeV2. This gluon distribution is predicted dicted to be much steeper and larger in the very smallx region (x<10?2) than usually assumed. Applications to deep inelastic scaling violations and heavy quark (c, b, t) contribution are discussed and presented as well as hadronic heavy quark production at SSC/LHC energies. For example, the \(b\bar b\) production rate at 40 TeV is predicted to be about an order of magnitude larger than that estimated with other gluon distributions so far. 相似文献