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51.
In this study, neutron-emission spectra produced by (n, xn) reactions for some structural fusion materials as 27Al, 51V, 52Cr, 55Mn, and 56Fe have been investigated by a neutron beam up to 16 MeV. Multiple preequilibrium mean-free-path constant from internal transition
and the preequilibrium and equilibrium level-density parameters have been investigated for some (n, xn) neutron-emission spectra calculated in this study. Preequilibrium neutron-emission spectra were calculated by using new-evaluated
hybrid model and geometry-dependent hybrid model, full-exciton model, and cascade-exciton model. The reaction equilibrium
component was calculated by Weisskopf-Ewing model. The obtained results have been discussed and compared with the available
experimental data and found agreement with each other.
The text was submitted by the authors in English. 相似文献
52.
Kaplan L 《Physical review letters》2002,89(18):184103
Recent images of electron flow through a two-dimensional electron gas device show branching behavior that is reproduced in numerical simulations of motion in a correlated random potential [M. A. Topinka, Nature 410, 183 (2001)]]. We show how such branching arises from caustics in the classical flow and find a simple scaling behavior of the branching under variation of the random potential strength. Analytic results describing statistical properties of the branching are confirmed by classical and quantum numerical tests. 相似文献
53.
Kaplan L Heller EJ 《Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics》1999,59(6):6609-6628
The phenomenon of periodic orbit scarring of eigenstates of classically chaotic systems is attracting increasing attention. Scarring is one of the most important "corrections" to the ideal random eigenstates suggested by random matrix theory. This paper discusses measures of scars and in so doing also tries to clarify the concepts and effects of eigenfunction scarring. We propose a universal scar measure which takes into account an entire periodic orbit and the linearized dynamics in its vicinity. This measure is tuned to pick out those structures which are induced in quantum eigenstates by unstable periodic orbits and their manifolds. It gives enhanced scarring strength as measured by eigenstate overlaps and inverse participation ratios, especially for longer orbits. We also discuss off-resonance scars which appear naturally on either side of an unstable periodic orbit. 相似文献
54.
The width of the free electron cyclotron resonance in InSb has been studied as a function of resonant magnetic field, by means of laser spectrometers operating at seven different wavelengths. Comparison of the data with theories of line width in the quantum limit, shows that the nature of the field dependence is determined by the size of the parameter l/a, where l is the magnetic length and a the screening length. 相似文献
55.
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58.
C.L. Littler D.G. Seiler R. Kaplan R.J. Wagner W. Zawadzki 《Solid State Communications》1981,37(10):783-788
High resolution photoconductivity and transmission spectra in p-InSb are obtained over a wide temperature range at magnetic fields from 9 to 100 kG using a CO2 laser. The low temperature results are described in terms of hole transitions from the acceptor ground state to excited states associated with free light-hole Landau states. 相似文献
59.
The real and quaternionic charge conjugation operators invariant under the infinite-dimensional Clifford algebra, or compatible with the Fermi algebra, are determined. There results a maze of inequivalent irreducible charged representations, all of which are non-Fock. The representation vectors and their charges admit two interpretations besides those of spinors or states of quantum fields: as wavelets on the circle, with charge conjugations acting via ordinary complex conjugation; and as infinite-dimensional numbers, with charge conjugations acting by automorphisms. 相似文献
60.
We consider a class of theories in which neutrino masses depend significantly on environment, as a result of interactions with the dark sector. Such theories of mass varying neutrinos were recently introduced to explain the origin of the cosmological dark energy density and why its magnitude is apparently coincidental with that of neutrino mass splittings. In this Letter we argue that in such theories neutrinos can exhibit different masses in matter and in vacuum, dramatically affecting neutrino oscillations. As an example of modifications to the standard picture, we consider simple models that may simultaneously account for the LSND anomaly, KamLAND, K2K, and studies of solar and atmospheric neutrinos, while providing motivation to continue to search for neutrino oscillations in short baseline experiments such as BooNE. 相似文献