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991.
Let k be a commutative ring, GG finite affine algebraic k-groups, and HH the dual Hopfalgebras of the affine algebras of G resp. G. The main results of this paper are: (I) If k is semilocal (e.g. k a field) there is an H-linear, HH-colinear, unitary, augmented isomorphism HHH H, where HH is the coalgebra belonging to G/G. (II) If the k-submodule of the fixelements of (HH)* is isomorphic to k (e.g. k principal or semilocal), then HH is a Frobeniusextension of the second kind. 相似文献
992.
All-solid-state neodymium-based single-frequency master-oscillator fiber power-amplifier system emitting 5.5 W of radiation at 1064 nm 总被引:1,自引:0,他引:1
We demonstrate a master-oscillator fiber power-amplifier system consisting of a diode-pumped monolithic nonplanar ring oscillator as the master oscillator and a Nd:glass double-clad fiber as the power amplifier. The system emits up to 5.5 W of single-frequency radiation at a wavelength of 1064 nm with an M(2) value of ~1.1 . The optical emission spectrum is investigated with respect to the background of residual amplified spontaneous emission. Spectrally resolved amplitude-noise behavior is examined. Further power-scaling possibilities are discussed. 相似文献
993.
Alois Würger 《Zeitschrift für Physik B Condensed Matter》1993,93(1):109-118
With increasing external-field amplitude the dynamics of a driven two-level system shows a cross-over from the weak-coupling or linear-response behaviour to a non-linear regime which is characterised by the appearance of Rabi oscillations, a field-dependent dynamical susceptibility, saturation of energy dissipation and additional frequencies in the correlation function. The system any initial distribution will relax towards a stationary state with a time-dependent polarisation vector. These features are derived from the propagator of the two-level system which is calculated using a perturbative scheme with a well-defined small parameter; the roatating-wave approximation of the Bloch equations is avoided. the dynamical behaviour is discussed by means of correlation and response functions. 相似文献
994.
The formalism to include a three-nucleon force into three-nucleon continuum calculations is presented. First numerical results, obtained in momentum space, are shown. The two- and three-nucleon forces have been restricted to act only in the1
S
0 and3
S
1-3
D
1 partial-wave states. As two-nucleon interaction the Bonn-B potential and as three-nucleon interaction the Tucson-Melbourne two-pion exchange model has been used. 相似文献
995.
996.
Jürgen Timm 《Archiv der Mathematik》1969,20(5):485-490
Ohne Zusammenfassung 相似文献
997.
H. Jung L. Jönsson H. Küster 《The European Physical Journal C - Particles and Fields》1999,9(3):383-388
The measurement of forward jet cross sections has been suggested as a promising probe of new small x parton dynamics and the question is whether the new HERA data provide an indication of this. In this paper the influence
of resolved photon processes has been investigated and it has been studied to what extent the inclusion of such processes
in addition to normal deep inelastic scattering leads to agreement with data. It is shown that two DGLAP evolution chains
from the hard scattering process towards the proton and the photon respectively, are sufficient to describe effects observed
in the HERA data, which have been attributed to BFKL dynamics.
Received: 11 March 1999 / Published online: 18 June 1999 相似文献
998.
L. Schimansky-Geier H. Hempel R. Bartussek Ch. Zülicke 《Zeitschrift für Physik B Condensed Matter》1995,96(3):417-427
We investigate a standard model for bistable reaction-diffusion-systems, which shares characteristic properties with the van-der-Pol oscillator for distributed generators and the FitzHugh-Nagumo system. In this system we study the effect of a long ranging inhibitor. As a main result we show the existence of two inhomogeneous stationary solutions—the smaller one is always a saddle which corresponds to a critical nucleus, while the larger one arises as astable solution. In carrying out the linear stability analysis for these solutions, we have to treat the Schrödinger-equation for a double-well potential. This is done approximately by a supersymmetric approach which yields the eigenvalues and eigenfunctions of the Schrödinger-equation. Furthermore we compare our analytical findings with numerical results-especially the occurrence of oscillating solutions is shown. 相似文献
999.
1000.
Under the assumptions thatq is not a root of unity and that the differentialsdu
j
i
of the matrix entries span the left module of first order forms, we classify bicovariant differential calculi on quantum groupsA
n–1
,B
n
,C
n
andD
n
. We prove that apart one dimensional differential calculi and from finitely many values ofq, there are precisely2n such calculi on the quantum groupA
n–1
=SL
q
(n) forn3. All these calculi have the dimensionn
2. For the quantum groupsB
n
,C
n
andD
n
we show that except for finitely manyq there exist precisely twoN
2-dimensional bicovariant calculi forN3, whereN=2n+1 forB
n
andN=2n forC
n
,D
n
. The structure of these calculi is explicitly described and the corresponding ad-invariant right ideals of ker are determined. In the limitq1 two of the 2n calculi forA
n–1
and one of the two calculi forB
n
,C
n
andD
n
contain the ordinary classical differential calculus on the corresponding Lie group as a quotient. 相似文献