Now showing items 263-282 of 1222

  • Digital clocks: simple Boolean models can quantitatively describe circadian systems 

    Akman, Ozgur E.; Watterson, Steven; Parton, Andrew; Binns, Nigel; Millar, Andrew J.; Ghazal, Peter (Royal Society, 2012)
    The gene networks that comprise the circadian clock modulate biological function across a range of scales, from gene expression to performance and adaptive behaviour. The clock functions by generating endogenous rhythms ...
  • Dirac-like plasmons in honeycomb lattices of metallic nanoparticles 

    Weick, Guillaume; Woollacott, Claire; Barnes, William L.; Hess, Ortwin; Mariani, Eros (American Physical Society, 2013)
    We consider a two-dimensional honeycomb lattice of metallic nanoparticles, each supporting a localized surface plasmon, and study the quantum properties of the collective plasmons resulting from the near-field dipolar ...
  • Direct excitation of propagating spin waves by focused ultrashort optical pulses. 

    Au, Y.; Dvornik, Mykola; Davison, T.; Ahmad, E.; Keatley, Paul Steven; Vansteenkiste, A.; Van Waeyenberge, B.; Kruglyak, V.V. (American Physical Society, 2013)
    An all-optical experiment long utilized to image phonons excited by ultrashort optical pulses has been applied to a magnetic sample. In addition to circular ripples due to surface acoustic waves, we observe an X-shaped ...
  • Direct mapping of surface plasmon dispersion using imaging scatterometry 

    Hibbins, Alastair P.; Constant, Thomas J.; Lethbridge, Alfred J.; Sambles, J. Roy; Stone, Edmund K.; Vukusic, Peter (American Institute of Physics, 2013)
    The iso-frequency contours of diffracted surface plasmons on metallic bigratings have been directly recorded using imaging scatterometry. Metallic rectangular bigratings, formed of two “crossed” surface relief gratings, ...
  • Direct Observation of Electron-to-Hole Energy Transfer in CdSe Quantum Dots 

    Hendry, Euan; Koeberg, Mattijs; Wang, F.; Zhang, H.; de Mello Donegá, C.; Vanmaekelbergh, D.; Bonn, Mischa (American Physical Society, 2006)
    We independently determine the subpicosecond cooling rates for holes and electrons in CdSe quantum dots. Time-resolved luminescence and terahertz spectroscopy reveal that the rate of hole cooling, following photoexcitation ...
  • Direct Optical Quantification of Backflow in a 90° Twisted Nematic Cell 

    Smith, N. J.; Tillin, M. D.; Sambles, J. Roy (American Physical Society, 2002)
    Optical guided mode observations of the transient director profile (optical tensor distribution) during the relaxation of a 90° twisted nematic cell directly reveals backflow. In the first 6 ms of the relaxation process, ...
  • Disciplines, geography, and gender in the framing of climate change 

    O'Neill, Saffron J.; Hulme, Mike; Turnpenny, John; Screen, James A. (American Meteorological Society, 2010)
    No abstract available
  • Discovery of a bright eclipsing cataclysmic variable 

    Sing, David K.; Green, E.M.; Howell, S.B.; Holberg, J.B.; Lopez-Morales, M.; Shaw, J.S.; Schmidt, G.D. (EDP Sciences for European Southern Observatory (ESO), 2007)
    Aims.We report on the discovery of J0644+3344 , a bright, deeply-eclipsing cataclysmic variable (CV) binary. Methods.Optical photometric and spectroscopic observations were obtained to determine the nature and characteristics ...
  • Discrete computation using a perturbed heteroclinic network 

    Ashwin, Peter; Borresen, Jon (Elsevier, 2005)
    Transient synchronization into clusters appears in many biological and physical systems and seems to be important for computation within neural systems. In this paper we show how one can robustly and effectively perform ...
  • Dispersion of collective magnonic modes in stacks of nanoscale magnetic elements 

    Dvornik, Mykola; Kruglyak, V.V. (American Physical Society, 2011)
    We report a numerical study of the dispersion of collective magnonic modes in magnonic crystals formed by stacks of magnetostatically coupled magnetic nanoelements. The calculations reveal that the sign of the magnonic ...
  • Dispersion of surface plasmon polaritons on short-pitch metal gratings 

    Hooper, Ian R.; Sambles, J. Roy (American Physical Society, 2002)
    The dispersion of surface plasmon polaritons (SPPs) has been calculated for short-pitch metal gratings for various depths. For gratings with depths greater than their pitch very flat SPP bands are formed in the zero-order ...
  • Distance Metric Learning with Eigenvalue Optimization 

    Ying, Yiming; Peng, Li (Microtome Publishing, 2012)
    The main theme of this paper is to develop a novel eigenvalue optimization framework for learning a Mahalanobis metric. Within this context, we introduce a novel metric learning approach called DML-eig which is shown to ...
  • Divergence of Casimir stress in inhomogeneous media 

    Simpson, William M.R.; Horsley, S.A.R.; Leonhardt, Ulf (American Physical Society, 2013)
    We examine the local behavior of the regularized stress tensor commonly used in calculations of the Casimir force for a dielectric medium inhomogeneous in one direction. It is shown that the usual expression for the stress ...
  • DMAC Fatigued Shackle 

    Vickers, Andrew; Gordelier, Tessa (University of Exeter, 2013-06-04)
    Results, photos and video footage of shackle tests at DMaC. Shackle trials conducted to determine shackle behaviour of a 2.5t rated shackle for research into mooring line reliability. Break tests and fatigue tests ...
  • Domain-wall pinning, nonadiabatic spin-transfer torque, and spin-current polarization in permalloy wires doped with vanadium 

    Lepadatu, S.; Claydon, J.S.; Kinane, C.J.; Charlton, T.R.; Langridge, Sean; Potenza, A.; Dhesi, Sarnjeet S.; Keatley, Paul Steven; Hicken, R.J.; Hickey, B.J.; Marrows, C.H. (American Physical Society, 2010)
    Using pulsed-current measurements we investigate the domain-wall depinning via spin-transfer torque from pinning potentials in V-doped Ni80Fe20 wires. The domain-wall depinning boundary, showing the variation of threshold ...
  • Dominance Measures for Multi-Objective Simulated Annealing 

    Smith, Kevin I.; Everson, Richard M.; Fieldsend, Jonathan E. (Institute of Electrical and Electronics Engineers (IEEE), 2004)
    Simulated annealing (SA) is a provably convergent optimiser for single-objective (SO) problems. Previously proposed MO extensions have mostly taken the form of an SO SA optimising a composite function of the objectives. ...
  • Dominance-Based Multiobjective Simulated Annealing 

    Smith, Kevin I.; Everson, Richard M.; Fieldsend, Jonathan E.; Murphy, Chris; Misra, Rashmi (Institute of Electrical and Electronics Engineers (IEEE), 2008)
    Simulated annealing is a provably convergent optimizer for single-objective problems. Previously proposed multiobjective extensions have mostly taken the form of a single-objective simulated annealer optimizing a composite ...
  • Double circulant constructions of the Leech lattice 

    Chapman, Robin (Cambridge University Press (CUP), 2000)
  • Double-period zero-order metal gratings as effective selective absorbers 

    Tan, W.-C.; Sambles, J. Roy; Preist, T. W. (American Physical Society, 2000)
    The electromagnetic response of a zero-order metal grating having a primary deep short-period component and a shallow long-period component is modeled. It is found that such a metal grating has an unusual surface-plasmon-polariton ...
  • Dramatic interannual changes of perennial Arctic sea ice linked to abnormal summer storm activity 

    Screen, James A.; Simmonds, Ian; Keay, Kevin (American Geophysical Union, 2011)
    The perennial (September) Arctic sea ice cover exhibits large interannual variability, with changes of over a million square kilometers from one year to the next. Here we explore the role of changes in Arctic cyclone ...