Now showing items 583-602 of 911

  • Pair contact process with diffusion: Failure of master equation field theory 

    Janssen, H. K.; van Wijland, F.; Deloubriere, O.; Tauber, U. C. (American Physical Society, 2004-11)
    We demonstrate that the "microscopic" field theory representation, directly derived from the corresponding master equation, fails to adequately capture the continuous nonequilibrium phase transition of the pair contact ...
  • partnership for research & education in plants (prep): involving high school students in authentic research in collaboration with scientists 

    Brooks, E.; Dolan, E.; Tax, F. (University of California Press, 2011-03)
    A partnership between scientists, high school teachers, and their students provides authentic research experiences to help students understand the nature and processes of science. The Partnership for Research and Education ...
  • Passive range estimation using subarray parallax 

    Hinich, Melvin J. (Acoustical Society of America, 1979-05)
    Consider a large aperture linear array which is detecting coherent radiation from a source. Suppose that the array is processed as a string of subarrays consisting of adjacent sensors. Assume that the signal is a plane ...
  • Path-integral approach to the Hubbard model 

    Weng, Z. Y.; Ting, C. S.; Lee, T. K. (American Physical Society, 1991-02)
    A path-integral approach to the Hubbard model is developed for the whole range of the coupling strength U. At half filling, the strong-coupling results are readily reproduced within the simple Gaussian fluctuations. The ...
  • pattern-recognition with wavelength-multiplexed filters 

    Case, S. K. (Optical Society of America, 1979-08)
    Wavelength-multiplexed matched spatial filters are used in an incoherent optical pattern recognition system. The system produces color-coded correlation responses which allow the simultaneous recognition of several objects ...
  • patterns in soil fertility and root herbivory interact to influence fine-root dynamics 

    Stevens, G. N.; Jones, R. H. (Ecological Society of America, 2006-03)
    Fine-scale soil nutrient enrichment typically stimulates root growth, but it may also increase root herbivory, resulting in trade-offs for plant species and potentially influencing carbon cycling patterns. We used root ...
  • patterns of coexistence in synaptomys cooperi and microtus pennsylvanicus 

    Linzey, A. V. (Ecological Society of America, 1984)
    The microtine rodents Synaptomys cooperi and Microtus pennsylvanicus are sympatric, have a similar life styles, and occur in the same general habitats. The object of this study was to determine the importance of competition ...
  • Peace, Global Warming, Ecological Overshoot, and Resource Wars 

    Cairns, John (Virginia Tech, 2014-01-22)
    In addition to the usual threats to world peace, a number of other destabilizing factors affect human society: global warming, ecological overshoot, and resource wars. These factors are interactive and often have positive ...
  • Percolation-enhanced supersolids in the extended Bose-Hubbard model 

    Kemburi, B. M.; Scarola, V. W. (American Physical Society, 2012-01-04)
    We theoretically study the stability of lattice supersolid states in the extended Bose-Hubbard model with bounded spatial disorder. We construct a disorder mean-field theory and compare with quantum Monte Carlo calculations. ...
  • Performance of the Los Alamos National Laboratory spallation-driven solid-deuterium ultra-cold neutron source 

    Saunders, A.; Makela, M.; Bagdasarova, Y.; Back, H. O.; Boissevain, J.; Broussard, L. J.; Bowles, T. J.; Carr, R.; Currie, S. A.; Filippone, B.; Garcia, A.; Geltenbort, P.; Hickerson, K. P.; Hill, R. E.; Hoagland, J.; Hoedl, S.; Holley, A. T.; Hogan, G.; Ito, T. M.; Lamoreaux, Steve; Liu, Chen-Yu; Liu, J.; Mammei, R. R.; Martin, J.; Melconian, D.; Mendenhall, M. P.; Morris, C. L.; Mortensen, R. N.; Pattie, R. W., Jr.; Pitt, M.; Plaster, B.; Ramsey, J.; Rios, R.; Sallaska, A.; Seestrom, S. J.; Sharapov, E. I.; Sjue, S.; Sondheim, W. E.; Teasdale, W.; Young, A. R.; VornDick, B.; Vogelaar, R. B.; Wang, Z.; Xu, Yanping (AIP Publishing, 2013-01)
    In this paper, we describe the performance of the Los Alamos spallation-driven solid-deuterium ultra-cold neutron (UCN) source. Measurements of the cold neutron flux, the very low energy neutron production rate, and the ...
  • Phantom Land and Ghost Slave: Humankind's Addiction to Fossil Energy 

    Cairns, John (Asian Journal of Experimental Sciences, 2014-01-22)
    Humankind uses vast amounts of fossil energy accumulated millions of years ago. The rate of use is many orders of magnitude greater than the replacement rate. Peak oil is the most immediate problem, and replacing this rate ...
  • Phase-locked loops, demodulation, and averaging approximation time-scale extensions 

    Chicone, C.; Heitzman, M. T. (Siam Publications, 2013)
    Among the many applications of the phase-locked loop (PLL), a device used extensively in telecommunications and electronics, is the demodulation of modulated carrier signals. The PLL contains a voltage controlled oscillator ...
  • Phenomenology of aging in the Kardar-Parisi-Zhang equation 

    Henkel, M.; Noh, J. D.; Pleimling, M. (American Physical Society, 2012-03-27)
    We study aging during surface growth processes described by the one-dimensional Kardar-Parisi-Zhang equation. Starting from a flat initial state, the systems undergo simple aging in both correlators and linear responses, ...
  • phosphorus spiraling in a woodland stream: seasonal-variations 

    Mulholland, P. J.; Newbold, J. D.; Elwood, J. W.; Ferren, L. A.; Webster, J. R. (Ecological Society of America, 1985)
    Four radiotracer releases were performed over an annual period in 1981-1982 to determine seasonal variation in indices and pathways of phosphorus spiralling in Walker Branch, a small woodland stream in eastern Tennessee, ...
  • Photogeneration action spectroscopy of neutral and charged excitations in films of a ladder-type poly(para-phenylene) 

    Wohlgenannt, M.; Graupner, W.; Leising, G.; Vardeny, Z. V. (American Physical Society, 1999-04-19)
    The photogeneration quantum efficiency action spectra of long-lived neutral and charged excitations in films of a ladder-type poly(para-phenylene) were measured. We found that both tripler and polaron action spectra show, ...
  • Photogeneration and recombination processes of neutral and charged excitations in films of a ladder-type poly(para-phenylene) 

    Wohlgenannt, M.; Graupner, W.; Leising, G.; Vardeny, Z. V. (American Physical Society, 1999-08-15)
    We introduce a version of the cw photomodulation technique, measured far from the steady state, for obtaining the quantum efficiency, eta, of long-lived photoexcitations in pi-conjugated polymers. We apply this technique ...
  • Photoinduced spin-polarized current in InSb-based structures 

    Frazier, Matthew; Cates, Jonathan G.; Waugh, Justin A.; Heremans, Jean J.; Santos, Michael B.; Liu, Xifan; Khodaparast, Giti A. (American Institute of Physics, 2009-11-15)
    We demonstrate the observation of spin-polarized photocurrent in InSb films grown on GaAs and InP substrates and InSb quantum wells where a nonequilibrium spin population has been achieved by using circularly polarized ...
  • Photoluminescence lineshape and dynamics of localized excitonic transitions in InAsP epitaxial layers 

    Merritt, T. R.; Meeker, M. A.; Magill, B. A.; Khodaparast, Giti A.; McGill, S.; Tischler, J. G.; Choi, S. G.; Palmstrom, C. J. (American Institute of Physics, 2014-05-21)
    The excitonic radiative transitions of InAsxP1-x (x = 0.13 and x = 0.40) alloy epitaxial layers were studied through magnetic field and temperature dependent photoluminescence and time-resolved photoluminescence spectroscopy. ...
  • Phyllopshere Bacterial Community Structure of Spinach (Spinacia oleracea) as Affected by Cultivar and Environmental Conditions at Time of Harvest 

    Lopez-Velasco, Gabriela; Welbaum, Gregory E.; Falkinham III, Joseph O.; Ponder, Monica A. (MDPI, 2011-12-20)
    Modern molecular ecology techniques were used to demonstrate the effects of plant genotype and environmental conditions prior to harvest on the spinach epiphytic bacterial community. Three cultivars of spinach with different ...
  • Phylogeny of the caryophyllales sensu lato: revisiting hypotheses on pollination biology and perianth differentiation in the core caryophyllales 

    Brockington, S. F.; Alexandre, R.; Ramdial, J.; Moore, M. J.; Crawley, S.; Dhingra, A.; Hilu, K.; Soltis, D. E.; Soltis, P. S. (University of Chicago Press, 2009-06)
    Molecular phylogenetics has revolutionized our understanding of the Caryophyllales, and yet many relationships have remained uncertain, particularly at deeper levels. We have performed parsimony and maximum likelihood ...