7,772 research outputs found
Fluctuations in the transmission properties of a quantum dot with interface roughness and impurities
We examine statistical fluctuations in the transmission properties of quantum dots with interface roughness and neutral impurities. For this purpose we employ a supercell model of quantum transport capable of simulating potential variations in three dimensions. We find that sample to sample variations in interface roughness in a quantum dot waveguide can lead to substantial fluctuations in the n=1 transmission resonance position, width and maximum. We also find that a strongly attractive impurity near the centre of a quantum dot can reduce these fluctuations. Nevertheless, the presence of more than a single impurity can give rise to a complex resonance structure that varies with impurity configuration
Effect of vibration in combined axes on subjective evaluation of ride quality
The effects of simultaneous sinusoidal vibration in the vertical and lateral axes on ratings of discomfort were investigated. The first experiment concentrated on the effects of variation of frequency in the two axes, and the second study concentrated on the effects of amplitude variation in the two axes
Oocyte cryopreservation as an adjunct to the assisted reproductive technologies
The document attached has been archived with permission from the editor of the Medical Journal of Australia. An external link to the publisherâs copy is included. See page 2 of PDF for this item.Keith L Harrison, Michelle T Lane, Jeremy C Osborn, Christine A Kirby, Regan Jeffrey, John H Esler and David Mollo
The âYear of Careâ in Leeds: implications for primary care practice
There is a growing policy discourse and empirical evidence which suggests a need for a shift in the way that care is delivered for people with long-term conditions â moving from an expert-driven consultation to one based on collaboration and partnership. Year of Care is an approach to managing long-term conditions, focused on personalised care planning whereby patients work together with the clinician using a collaborative process of shared decision-making to agree goals, identify support needs, develop and implement action plans, and monitor progress. This paper reports the learning from implementing Year of Care in Leeds where nine âearly adopterâ sites rolled-out the programme. Process and delivery issues are highlighted in the paper, including the challenge of navigating cultural change in General Practice and training and support issues. It is anticipated that this learning and insight will have utility beyond Leeds to other areas adopting greater patient centred care models
Dissociative Autoionization in (1+2)-photon Above Threshold Excitation of H2 Molecules
We have theoretically studied the effect of dissociative autoionization on
the photoelectron energy spectrum in (1+2)-photon above threshold
ionization(ATI) of H2 molecules. We have considered excitation from the ground
state X-singlet-Sigma-g+(v=0,j) to the doubly excited autoionizing states of
singlet-Sigma-u+ and singlet-Pi-u+ symmetry, via the intermediate resonant
B-singlet-Sigma-u+(v=5,j) states. We have shown that the photoelectron energy
spectrum is oscillatory in nature and shows three distinct peaks above the
photoelectron energy 0.7 eV. This feature has been observed in a recent
experiment by Rottke et al, J. Phys. B, Vol. 30, p-4049 (1997).Comment: 11 pages and 4 figure
Witten's Invariants of Rational Homology Spheres at Prime Values of and Trivial Connection Contribution
We establish a relation between the coefficients of asymptotic expansion of
trivial connection contribution to Witten's invariant of rational homology
spheres and the invariants that T.~Ohtsuki extracted from Witten's invariant at
prime values of . We also rederive the properties of prime invariants
discovered by H.~Murakami and T.~Ohtsuki. We do this by using the bounds on
Taylor series expansion of the Jones polynomial of algebraically split links,
studied in our previous paper. These bounds are enough to prove that Ohtsuki's
invariants are of finite type. The relation between Ohtsuki's invariants and
trivial connection contribution is verified explicitly for lens spaces and
Seifert manifolds.Comment: 32 pages, no figures, LaTe
Domain Dynamics of Magnetic Films with Perpendicular Anisotropy
We study the magnetic properties of nanoscale magnetic films with large
perpendicular anisotropy comparing polarization microscopy measurements on
Co_28Pt_72 alloy samples based on the magneto-optical Kerr effect with Monte
Carlo simulations of a corresponding micromagnetic model. We focus on the
understanding of the dynamics especially the temperature and field dependence
of the magnetisation reversal process. The experimental and simulational
results for hysteresis, the reversal mechanism, domain configurations during
the reversal, and the time dependence of the magnetisation are in very good
qualitative agreement. The results for the field and temperature dependence of
the domain wall velocity suggest that for thin films the hysteresis can be
described as a depinning transition of the domain walls rounded by thermal
activation for finite temperatures.Comment: 7 pages Latex, Postscript figures included, accepted for publication
in Phys.Rev.B, also availible at:
http://www.thp.Uni-Duisburg.DE/Publikationen/Publist_Us_R.htm
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