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941.
Reinhard A Cubel Liebisch T Younge KC Berman PR Raithel G 《Physical review letters》2008,100(12):123007
In rubidium Rydberg states, the collision nD_(5/2)+nD_(5/2)-->(n-2)F_(7/2)+(n+2)P_(3/2) is nearly resonant in the vicinity of n=43. As a result, over a short range of n centered around n approximately 43 the Rydberg-Rydberg interaction potential is quite large and turns from repulsive to attractive [Phys. Rev. A 75, 032712 (2007)10.1103/PhysRevA.75.032712]. We use state-selective field ionization to investigate the effect of this resonance on instantaneous excitation of mixed two-particle states, state-mixing collisions, and Penning ionization. We find that these processes depend on the magnitude and sign of the two-particle interaction potential, and thus on n near the resonance. The large magnitude of the observed state mixing provides evidence for many-body effects. 相似文献
942.
943.
Reinhard Demuth 《Nachrichten aus der Chemie》2008,56(6):715-716
944.
945.
946.
In the present paper we describe the use of group actions, double cosets and homomorphisms in the constructive theory of discrete structures, as we found it useful from both a theoretical and a practical point of view. By means of examples we should like to demonstrate that these methods are useful both as unifying principles and as efficient methods for applications. 相似文献
947.
It is proved that the Stokes operator in Lq -space on an infinite cylindrical domain of
,
, with several exits to infinity generates a bounded and exponentially decaying analytic semigroup and admits a bounded
-calculus. For the resolvent estimates, the Stokes resolvent system with a prescribed divergence in an infinite straight
cylinder with bounded cross-section
is studied in L
q
where
and
is an arbitrary Muckenhoupt weight. The proofs use cut-off techniques and the theory of Schauder decomposition of UMD spaces based on
-boundedness of operator families and on square function estimates involving Muckenhoupt weights. 相似文献
948.
Slawomir Kwasik Reinhard Schultz 《Proceedings of the American Mathematical Society》1999,127(5):1525-1532
Given a manifold of dimension at least 4 whose universal covering is homeomorphic to a sphere, the main result states that a compact manifold is isomorphic to a cylinder if and only if is homotopy equivalent to this cylinder and the boundary is isomorphic to two copies of ; this holds in the smooth, PL and topological categories. The result yields a classification of smooth, finite group actions on homotopy spheres (in dimensions ) with exactly two singular points.
949.
Reinhard Wolf 《Israel Journal of Mathematics》1999,110(1):125-151
The average distance theorem of Gross implies that for each realN-dimensional Banach space (N≥2) there is a unique positive real numberr(E) with the following property: For each positive integern and for all (not necessarily distinct)x
1,x
2, …,x
n inE with ‖x
1‖=‖x
2‖=…=‖x
n‖=1, there exists anx inE with ‖x‖=1 such that
The main result of this paper shows, thatr(E)≤2−1/N for each realN-dimensional Banach spaceE (N≥2) with the so-called quasihypermetric property (which is equivalent toE isL
1-embeddable). Moreover, equality holds if and only ifE is isometrically isomorphic to ℝ
N
equipped with the usual 1-norm. 相似文献
950.
We show that the ‘directed diffusion equation’ with periodic boundary conditions has a unique weak solution u whenever b is measurable and bounded above and below by positive constants. Also, limt→∞u(t,x) in Lp, 1?p≤∞. 相似文献