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991.
992.
The electron localization is studied for Anderson's tight-binding model with diagonal and off-diagonal disorder for a very large square lattice (10,000 sites) and diamond lattice (27,000 sites). The numerical investigations are based on the Lanczos recursion method. The convergence of the recursion coefficientsa
n
,b
n
is discussed with regard to the electron localization.From Anderson's criterion and an exact real space renormalization method the energy of the localization edge is found as a function of the degree of disorder. Also the dependence of the spatial decay rate of localized wave functions on the energy and the degree of disorder is evaluated. Near the Anderson transition, where all states become localized, we get two critical exponentsv
E
andv
W
, which lead us to the tentative suggestion of multicritical scaling laws for this transition. 相似文献
993.
Excitation functions for a number of proton groups for the reactions 23Na(d, p)24Na and 27Al(d, p)28Al were measured in the energy range Ed = 1.5 to 3.0 MeV. The angular distributions for a number of proton groups were measured at a number of deuteron energies below 3.0 MeV for the three reactions 12C(d, p)13C, 23Na(d, p)24Na and 27Al(d, p)28Al. The theory of deuteron stripping reactions at incident energies below the Coulomb barrier has been considered. A closed analytical form for the differential cross-section has been obtained considering three cases according to the incident deuteron and outgoing proton energies. An attempt has been made to fit the angular distribution measurements at a number of deuterons bombarding energies accordingly. 相似文献
994.
U. Goginava 《Acta Mathematica Hungarica》2007,115(4):333-340
The main aim of this paper is to prove that the maximal operator
of the Fejér mean of the double Walsh-Fourier series is not bounded from the Hardy space H
1/2 to the space weak-L
1/2.
This paper was written during the visit of the author at the College of Nyíregyháza in Hungary. 相似文献
995.
Behavior of concrete cylinders confined by carbon-composite tapes and prestressed yarns 1. Experimental data 总被引:1,自引:0,他引:1
V. Tamuzs R. Tepfers Chi-Sang You T. Rousakis I. Repelis V. Skruls U. Vilks 《Mechanics of Composite Materials》2006,42(1):13-32
The results of a comprehensive test program for the mechanical behavior of round concrete specimens confined by carbon-fiber
epoxy tapes and prestressed carbon yarns are reported. Five different concrete batches of compressive strength from 20 to
100 MPa and the confinement of various thickness and pretension level were investigated. The specimens, which were subjected
to monotonic or repeated compressive loadings, showed a nonlinear stress-strain behavior with a significant ductility and
increased ultimate strength, in contrary to the brittle behavior of plain concrete. The limit of linearity on the stress-strain
diagrams of the confined concrete roughly coincided with the ultimate strength of plain concrete. Above this limit, the damage
accumulation and plastic deformations proceeded in the confined specimens. This fact was evidenced by the increasing slope
of deformation diagrams in unloadings and repeated loadings and by the pronounced residual strains. The limit of linearity
could be raised significantly by pretension of the carbon yarns during their winding.
Russian translation published in Mekhanika Kompozitnykh Materialov, Vol. 42, No. 1, pp. 21–44, January–February, 2006. 相似文献
996.
We investigate the dynamics of microcapsules in linear shear flow within a reduced model with two degrees of freedom. In previous
work for steady shear flow, the dynamic phases of this model, i.e. swinging, tumbling and intermittent behaviour, have been identified using numerical methods. In this paper, we integrate
the equations of motion in the quasi-spherical limit analytically for time-constant and time-dependent shear flow using matched
asymptotic expansions. Using this method, we find analytical expressions for the mean tumbling rate in general time-dependent
shear flow. The capsule dynamics is studied in more detail when the inverse shear rate is harmonically modulated around a
constant mean value for which a dynamic phase diagram is constructed. By a judicious choice of both modulation frequency and
phase, tumbling motion can be induced even if the mean shear rate corresponds to the swinging regime. We derive expressions
for the amplitude and width of the resonance peaks as a function of the modulation frequency. 相似文献
997.
998.
A. Chaudhuri C. Andreoiu M. Brodeur T. Brunner U. Chowdhury S. Ettenauer A. T. Gallant A. Grossheim G. Gwinner R. Klawitter A. A. Kwiatkowski K. G. Leach A. Lennarz D. Lunney T. D. Macdonald R. Ringle B. E. Schultz V. V. Simon M. C. Simon J. Dilling 《Applied physics. B, Lasers and optics》2014,114(1-2):99-105
The introduction of Paul traps, in particular linear radio-frequency quadrupoles in the early 2000s, has revolutionized the use of ion traps for probing the properties of radioactive nuclides. It opened the path to trapping all available nuclides, independent of their chemical properties. We present an overview of direct mass measurements of short-lived nuclides using TITAN, a Penning trap mass spectrometer facility particularly suitable for precision measurements of ms-half-life nuclides. 相似文献
999.
V. E. Antonov O. I. Barkalov M. Calvo-Dahlborg U. Dahlborg V. F. Fedotov A. I. Harkunov 《高压研究》2013,33(3-6):261-272
Abstract Phase transformations occurring in initially amorphous Zn41 Sb59 semiconductor at pressures to 10 GPa and temperatures to 350C were studied using the measurement of electrical resistance, in situ energy dispersive X-ray diffraction and neutron diffraction on quenched high-pressure phases at ambient pressure. The studied T- P region involves the regions of reversible and irreversible crystallisation and phase transitions between the equilibrium crystalline low-pressure and high-pressure phases. 相似文献
1000.
Asymmetric scaling of a square matrixA 0 is a matrix of the formXAX
–1 whereX is a nonnegative, nonsingular, diagonal matrix having the same dimension ofA. Anasymmetric scaling of a rectangular matrixB 0 is a matrix of the formXBY
–1 whereX andY are nonnegative, nonsingular, diagonal matrices having appropriate dimensions. We consider two objectives in selecting a symmetric scaling of a given matrix. The first is to select a scalingA of a given matrixA such that the maximal absolute value of the elements ofA is lesser or equal that of any other corresponding scaling ofA. The second is to select a scalingB of a given matrixB such that the maximal absolute value of ratios of nonzero elements ofB is lesser or equal that of any other corresponding scaling ofB. We also consider the problem of finding an optimal asymmetric scaling under the maximal ratio criterion (the maximal element criterion is, of course, trivial in this case). We show that these problems can be converted to parametric network problems which can be solved by corresponding algorithms.This research was supported by NSF Grant ECS-83-10213. 相似文献