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991.
We define a notion of an asymptotic upper curvature bound for Gromov hyperbolic metric spaces that is invariant under rough-isometries
and examine the basic properties of this concept.
M.B. was supported by NSF grants DMS 0200566 and DMS 0244421. Th.F. was supported by the Deutsche Forschungsgemeinschaft (FO
353/1-1). 相似文献
992.
Mario Calonghi 《Annali di Matematica Pura ed Applicata》1934,13(1):171-189
Sunto L'A. tratta della curvatura media e relativa di una varietà in ambienti riemanniani: poste in luce notevoli disuguaglianze
e una nuova definizione della curvatura media, introduce unavarietà centrale ed unaquadrica di curvatura associate ad ogni punto della varietà e ne dà proprietà notevoli. 相似文献
993.
A quantum Ising-like spin-j model, characterized by arbitrary multipole-multipole interactions as well as external fields, is proposed and analyzed. A thorough discussion of the algebraic properties of the dynamical variables (which belong to SU(2j+1)) is performed, whereby by the application of an improved version of the mean-field theory (which has the usual mean-field theory as its zeroeth order approximation) an explicit expression for the free energy is derived. 相似文献
994.
A holomorphic functionf defined on the unit disk d is called a Bloch function provided {fx73-02} For α ∃ (0,1] letB∞(α)denote the class of locally univalent Bloch functionsf normalized by ∥f∥B ≤1f(0) = 0 andf’(0) = α. A type of subordination theorem is established for B∞(α). This subordination theorem is used to derive sharp growth,
distortion, curvature and covering theorems for B∞(α).
Supported as a Feodor Lynen Fellow of the Alexander von Humboldt Foundation.
Research supported in part by a National Science Foundation grant. 相似文献
995.
The introduction of various new radiofrequency electrical discharges has placed increased emphasis on circuit design which provides optimal energy transfer between a generator and its corresponding spectroscopic “load”. This technology is well developed for high-frequency (ca. 27 MHz) inductively-coupled plasma discharges and for cavity discharges which operate in the microwave region (e.g., 2450 MHz). The 200-MHz very high frequency (VHF) region has received less attention. New circuitry is described which allows effective transfer of high power (5-kW), pulsed (2.5-μs), VHF (200-MHz) energy into a plasma suitable for analytical purposes. A triple-stub tuner is used in this circuitry. Comparison with other approaches and applicability to a variety of discharge systems are discussed. 相似文献
996.
Shengqiang Liu Edoardo Beretta 《Journal of Mathematical Analysis and Applications》2006,323(1):331-343
This paper considers a delay differential equation model for the interaction among n species, the adult members of which are in competition. For each of the n species the model incorporates an infinite distributed time delay which represents the time from birth to maturity of that species. Thus, the time delays appear in the adult recruitment terms. The dynamics of the model are determined, and sharp global stability criteria are established for the interior equilibrium as well as the axial equilibrium. 相似文献
997.
998.
999.
Fabrizio Esposito Iole Armenise Giulia Capitta Mario Capitelli 《Chemical physics》2008,351(1-3):91-98
A complete set of V–T (vibration–translation) relaxation rates and of dissociation coefficients for the system O–O2 have been obtained by using quasiclassical trajectories on the Varandas and Pais potential energy surface. The results, averaged on a Boltzmann rotational distribution, cover the whole range of the vibrational ladder and are reproduced in closed form ready to be implemented in state-to-state kinetic models. The accuracy of the results has been tested by comparing them with available experimental and theoretical values (ASI-CAST project is acknowledged). 相似文献
1000.