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21.
The idea of synthesizing a number of directly identified substructure models is developed. Each substructure is tested separately and a substructure model is determined from time domain test data. Structural modeling concepts significantly affect the substructure identification and substructure coupling. The effects are examined in detail. 相似文献
22.
Brussaard P Fisher SN Guénault AM Hale AJ Mulders N Pickett GR 《Physical review letters》2001,86(20):4580-4583
We report the first measurements of the A-B phase transition of superfluid 3He confined within 98% silica aerogel in high magnetic fields and low temperatures. A disk of aerogel is attached to a vibrating wire resonator. The resonant frequency yields a measure of the superfluid fraction rho(s)/rho of the 3He within the aerogel. The inferred rho(s)/rho value increases substantially at the A-to- B transition of the confined superfluid, allowing us to map the A-B phase diagram as a function of field and temperature. At 4.8 bars, the B-T transition curve looks very similar to that in bulk with a simple reduction factor of order 0.45 for both transition field and temperature. 相似文献
23.
Bertone PF Champagne AE Powell DC Iliadis C Hale SE Hansper VY 《Physical review letters》2001,87(15):152501
The energy derived from the CN cycle at low stellar temperatures is regulated by the 14N(p,gamma)15O reaction. A previous direct measurement of this reaction has been interpreted as showing evidence for a subthreshold resonance which makes a major contribution to the reaction rate at low temperatures. This resonance, at E(c.m.) = -504 keV would correspond to the known Ex = 6793-keV state in 15O. We have measured a mean lifetime of 1.60(+0.75)(-0.72) fs (90% C.L.) for this state using the Doppler-shift attenuation method. This lifetime is a factor of 15 longer than that inferred from the (p,gamma) data and implies that the contribution of the subthreshold resonance is negligible. 相似文献
24.
Abusaidi R Akerib DS Barnes PD Bauer DA Bolozdynya A Brink PL Bunker R Cabrera B Caldwell DO Castle JP Clarke RM Colling P Crisler MB Cummings A Da Silva A Davies AK Dixon R Dougherty BL Driscoll D Eichblatt S Emes J Gaitskell RJ Golwala SR Hale D Haller EE Hellmig J Huber ME Irwin KD Jochum J Lipschultz FP Lu A Mandic V Martinis JM Nam SW Nelson H Neuhauser B Penn MJ Perera TA Perillo Isaac MC Pritychenko B Ross RR Saab T Sadoulet B Schnee RW Seitz DN Shestople P Shutt T Smith A Smith GW 《Physical review letters》2000,84(25):5699-5703
The Cryogenic Dark Matter Search (CDMS) employs Ge and Si detectors to search for weakly interacting massive particles (WIMPs) via their elastic-scattering interactions with nuclei while discriminating against interactions of background particles. CDMS data, accounting for the neutron background, give limits on the spin-independent WIMP-nucleon elastic-scattering cross section that exclude unexplored parameter space above 10 GeV/c2 WIMP mass and, at >75% C.L., the entire 3sigma allowed region for the WIMP signal reported by the DAMA experiment. 相似文献
25.
In this study, the supersymmetric Wentzel-Kramers-Brillouin (SWKB) approximation method has been discussed in detail. The entire bound state energy eigenvalues and the ground state wave function of the q-deformed potentials such as Pöschl-Teller and Rosen-Morse potentials have been obtained by SWKB approximation. We have shown that our results are in complete agreement with the results obtained by E?rifes et al. (Physica Scripta 59:90–94, 1999; Physica Scripta 60:195–198, 1999). 相似文献
26.
27.
J. K. Hale 《Ukrainian Mathematical Journal》2007,59(2):293-314
Using observable quantities and state variable of a dynamical process, a general evolutionary equation is defined which unifies
classical ordinary differential equations, partial differential equations, and hereditary systems of retarded and neutral
type. Specific illustrations are given using transmission lines nearest-neighbor coupled at the boundary and the theory of
heat transfer in solids. Some spectral theory for linearization of the equations is also discussed.
Published in Ukrains’kyi Matematychnyi Zhurnal, Vol. 59, No. 2, pp. 268–288, February, 2007. 相似文献
28.
In this paper, we propose a novel algorithm for solving the classical P-median problem. The essential aim is to identify the optimal extended Lagrangian multipliers corresponding to the optimal solution of the underlying problem. For this, we first explore the structure of the data matrix in P-median problem to recast it as another equivalent global optimization problem over the space of the extended Lagrangian multipliers. Then we present a stochastic search algorithm to find the extended Lagrangian multipliers corresponding to the optimal solution of the original P-median problem. Numerical experiments illustrate that the proposed algorithm can effectively find a global optimal or very good suboptimal solution to the underlying P-median problem, especially for the computationally challenging subclass of P-median problems with a large gap between the optimal solution of the original problem and that of its Lagrangian relaxation. 相似文献
29.
30.
Using a pre-ionization system based on a silicon carbide compound and a pulse-forming network using a vacuum relay, we have been able to significantly reduce TEA0-CO2 laser complexity while maintaining high output energy densities. The design and construction are detailed along with the experimentally obtained laser characteristics. 相似文献