Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Engineering General  (1)
  • PACS. 73.63.Fg Nanotubes – 73.61.Wp Fullerenes and related materials – 73.22.-f Electronic structure of nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals  (1)
Material
Years
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 33 (2003), S. 365-372 
    ISSN: 1434-6036
    Keywords: PACS. 73.63.Fg Nanotubes – 73.61.Wp Fullerenes and related materials – 73.22.-f Electronic structure of nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract: The ac Stark effect is investigated in the toroidal carbon nanotube system threaded with an ac magnetic flux. The Floquet theory is employed to deal with the time-dependent quantum problems. The time-averaged energy of the system is derived and is found to exhibit a strong relationship with an external field, and the modified energy gap has been presented. The ac flux enhances energy gaps to cause metal-semiconductor transition. The steady current has been obtained by employing the free energy approach, and the persistent current is a special case as the magnitude of the ac flux approaches zero. The photon-assisted current is quite different from the persistent current due to the absorption and emission of photons. The local density of states is obtained by calculating the Green's function in the Floquet state, and photon-resonant structures are observed. All of the novel features are associated with the ac Stark effect, which is caused by the modification of energy levels.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 23 (1996), S. 19-27 
    ISSN: 0271-2091
    Keywords: turbulence ; channel flow ; low Reynolds number ; large-eddy simulation ; subgrid-scale model dynamic SGS model ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Several issues related to applications of the dynamic subgrid-scale (SGS) model in large-eddy simulation (LES) at low Reynolds number are investigated. A modified formulation of the dynamic model is constructed and its performance in low-Reynolds-number LES of channel flow is assessed through a comparison of length scales computed respectively by this modified model, the Germano-Lilly dynamic SGS model and two empirical wall damping functions with optimum model coefficients, which have been successfully used in many simulations of channel flows. Two values of the ratio of filter widths are set for each of the dynamic models. The results have confirmed that the modified dynamic SGS model gives the correct behaviour of the subgrid eddy viscosity in the region of a plane wall to an accuracy that exceeds the best-tuned wall damping function, and almost collapses with the theoretical behaviour of the length scale near the wall without any tuning and adjustment. In addition, the impact of the choice of the ratio of filter widths on the modified dynamic SGS model is found to be much less than with the Germano-Lilly model.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...