1,488,954 research outputs found

    2005 Oregon Harvest Report

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    This harvest report for the Oregon wine industry from 2005 discusses how the cooler temperatures and lower alcohol levels affected the vintages. The harvests were later and difficulties arose with autumn rains, but excellent wines were still made

    Nonadiabatic corrections to rovibrational levels of H2_2

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    The leading nonadiabatic corrections to rovibrational levels of a diatomic molecule are expressed in terms of three functions of internuclear distance: corrections to the adiabatic potential, the effective nuclear mass, and the effective moment of inertia. The resulting radial Schr\"odinger equation for nuclear motion is solved numerically yielding accurate nonadiabatic energies for all rovibrational levels of H2_2 molecule in excellent agreement with previous calculations by Wolniewicz.Comment: 14 page

    Towards energetically viable asymmetric deprotonations : selectivity at more elevated temperatures with C2-symmetric magnesium bisamides

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    A novel chiral magnesium bisamide has enabled the development of effective asymmetric deprotonation protocols at substantially more elevated temperatures. This new, structurally simple, C2-symmetric magnesium complex displays excellent levels of asymmetric efficiency and energy reduction in the synthesis of enantioenriched enol silane

    Variational Ansatz for PT-Symmetric Quantum Mechanics

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    A variational calculation of the energy levels of a class of PT-invariant quantum mechanical models described by the non-Hermitian Hamiltonian H= p^2 - (ix)^N with N positive and x complex is presented. Excellent agreement is obtained for the ground state and low lying excited state energy levels and wave functions. We use an energy functional with a three parameter class of PT-symmetric trial wave functions in obtaining our results.Comment: 9 pages -- one postscript figur

    Semiconductor quantum dots in high magnetic fields: The composite-fermion view

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    We review and extend the composite fermion theory for semiconductor quantum dots in high magnetic fields. The mean-field model of composite fermions is unsatisfactory for the qualitative physics at high angular momenta. Extensive numerical calculations demonstrate that the microscopic CF theory, which incorporates interactions between composite fermions, provides an excellent qualitative and quantitative account of the quantum dot ground state down to the largest angular momenta studied, and allows systematic improvements by inclusion of mixing between composite fermion Landau levels (called Λ\Lambda levels).Comment: 13 pages, 8 figure

    Negative-U properties for substitutional Au in Si

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    The isolated substitutional gold impurity in bulk silicon is studied in detail using electronic structure calculations based on density-functional theory. The defect system is found to be a non-spin-polarized negative-U centre, thus providing a simple solution to the long-standing debate over the electron paramagnetic resonance signal for gold in silicon. There is an excellent agreement (within 0.03 eV) between the well-established experimental donor and acceptor levels and the predicted stable charge state transition levels, allowing for the unambiguous assignment of the two experimental levels to the (1+/1-) and (1-/3-) transitions, respectively, in contrast to previously held assumptions about the system.Comment: 6 pages, 5 figure

    Exact solutions for vibrational levels of the Morse potential via the asymptotic iteration method

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    Exact solutions for vibrational levels of diatomic molecules via the Morse potential are obtained by means of the asymptotic iteration method. It is shown that, the numerical results for the energy eigenvalues of 7Li2^{7}Li_{2} are all in excellent agreement with the ones obtained before. Without any loss of generality, other states and molecules could be treated in a similar way

    Elemental boron doping behavior in silicon molecular beam epitaxy

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    Boron-doped Si epilayers were grown by molecular beam epitaxy (MBE) using an elemental boron source, at levels up to 2×1020 cm−3, to elucidate profile control and electrical activation over the growth temperature range 450–900 °C. Precipitation and surface segregation effects were observed at doping levels of 2×1020 cm−3 for growth temperatures above 600 °C. At growth temperatures below 600 °C, excellent profile control was achieved with complete electrical activation at concentrations of 2×1020 cm−3, corresponding to the optimal MBE growth conditions for a range of Si/SixGe1−x heterostructures

    Landau level mixing by full spin-orbit interactions

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    We study a two-dimensional electron gas in a perpendicular magnetic field in the presence of both Rashba and Dresselhaus spin-orbit interactions. Using a Bogoliubov transformation we are able to write an approximate formula for the Landau levels, thanks to the simpler form of the resulting Hamiltonian. The exact numerical calculation of the energy levels, is also made simpler by our formulation. The approximate formula and the exact numerical results show excellent agreement for typical semiconductors, especially at high magnetic fields. We also show how effective Zeeman coupling is modified by spin-orbit interactions.Comment: 5 pages, 5 figure

    International accessibility and rental levels: a case study for the office-market in the Netherlands

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    Rental levels of office floor space are determined by aspects of the buildings and aspects of the location. In this contribution we focus on the characteristics of locations using a large database of market-transactions. Accessibility proves to have an important impact on price levels. In particular the most expensive locations must have an excellent international accessibility by Air. Empirical results are presented.
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