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The differences between a full Lorentz-Lorenz potential modification, and a ?2 approximation to this modification are examined for low energy pion-nucleus elastic scattering. The relationship between these approaches and the single-scattering impulse approximation is also investigated. 相似文献
67.
Consider a continuous local martingale X. We say that X satisfies the representation property if any martingale Y of X can be represented as stochastic ITǒ integral of X. Using the method of random time change systematically, in the present paper the representation problem for continuous local martingales is treated. We describe a class of martingales Y that can be represented as stochastic integral of X by probabilistic conditions. This leads to sufficient conditions for the representation property of X being true. Besides, an interesting characterization of continuous processes with independent increments is obtained. In part II. we proceed with general examples, applications to the n-dimensional case, and, in particular, to the n-dimensional time change of continuous local martingales with orthogonal components. 相似文献
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The present study reports on experimental investigations about the phase velocity diagrams of Alfvén waves in the anisotropic solid-state plasma of bismuth. Alfvén-wave transmission at 34 GHz and 4.2 K has been observed, using an interference technique of high sensitivity. The experimental results are in good agreement with a theoretical model given by Buchsbaum, which makes only use of the anisotropic mass tensor of bismuth. 相似文献
69.
John?Bartley Thomas?Soltau Hereward?Wimborne Sunjun?Kim Angeline?Martin-Studdard David?Hess William?Hill Jennifer?Waller James?CarrollEmail author 《BMC neuroscience》2005,6(1):15
Background
Mechanisms that affect recovery from fetal and neonatal hypoxic-ischemic (H-I) brain injury have not been fully elucidated. The incidence of intrapartum asphyxia is approximately 2.5%, but the occurrence of adverse clinical outcome is much lower. One of the factors which may account for this relatively good outcome is the process of neurogenesis, which has been described in adult animals. We used a neonatal mouse model to assess new cells in the hippocampus after H-I injury. 相似文献70.
Niedermaier O Scheit H Bildstein V Boie H Fitting J von Hahn R Köck F Lauer M Pal UK Podlech H Repnow R Schwalm D Alvarez C Ames F Bollen G Emhofer S Habs D Kester O Lutter R Rudolph K Pasini M Thirolf PG Wolf BH Eberth J Gersch G Hess H Reiter P Thelen O Warr N Weisshaar D Aksouh F Van den Bergh P Van Duppen P Huyse M Ivanov O Mayet P Van de Walle J Aystö J Butler PA Cederkäll J Delahaye P Fynbo HO Fraile LM Forstner O Franchoo S Köster U Nilsson T Oinonen M Sieber T Wenander F Pantea M 《Physical review letters》2005,94(17):172501
We report on the first radioactive beam experiment performed at the recently commissioned REX-ISOLDE facility at CERN in conjunction with the highly efficient gamma spectrometer MINIBALL. Using 30Mg ions accelerated to an energy of 2.25 MeV/u together with a thin (nat)Ni target, Coulomb excitation of the first excited 2+ states of the projectile and target nuclei well below the Coulomb barrier was observed. From the measured relative deexcitation gamma-ray yields the B(E2;0(+)gs-->2(+)1) value of 30Mg was determined to be 241(31)e2 fm4. Our result is lower than values obtained at projectile fragmentation facilities using the intermediate-energy Coulomb excitation method, and confirms the theoretical conjecture that the neutron-rich magnesium isotope 30Mg resides outside the "island of inversion." 相似文献