1,088 research outputs found

    Intrinsic localized modes in the charge-transfer solid PtCl

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    We report a theoretical analysis of intrinsic localized modes in a quasi-one-dimensional charge-transfer-solid [Pt(en)2][Pt(en)2Cl2](ClO4)4[Pt(en)_2][Pt(en)_2 Cl_2](ClO_4)_4(PtCl). We discuss strongly nonlinear features of resonant Raman overtone scattering measurements on PtCl, arising from quantum intrinsic localized (multiphonon) modes (ILMs) and ILM-plus-phonon states. We show, that Raman scattering data displays clear signs of a non-thermalization of lattice degrees-of-freedom, manifested in a nonequilibrium density of intrinsic localized modes.Comment: 4 pages, 4 figures, REVTE

    A perturbative treatment for the energy levels of neutral atoms

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    Energy levels of neutral atoms have been re-examined by applying an alternative perturbative scheme in solving the Schrodinger equation for the Yukawa potential model with a modified screening parameter. The predicted shell binding energies are found to be quite accurate over the entire range of the atomic number ZZ up to 84 and compare very well with those obtained within the framework of hyper-virial-Pade scheme and the method of shifted large-N expansion. It is observed that the new perturbative method may also be applied to the other areas of atomic physics.Comment: 18 page

    Bouncing Neutrons and the Neutron Centrifuge

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    The recent observation of the quantum state of the neutron bouncing freely under gravity allows some novel experiments. A method of purifying the ground state is given, and possible applications to the measurement of the electric dipole moment of the neutron and the short distance behaviour of gravity are discussed.Comment: 7 pages, 7 figure

    Reconciling Semiclassical and Bohmian Mechanics: III. Scattering states for continuous potentials

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    In a previous paper [J. Chem. Phys. 121 4501 (2004)] a unique bipolar decomposition, Psi = Psi1 + Psi2 was presented for stationary bound states Psi of the one-dimensional Schroedinger equation, such that the components Psi1 and Psi2 approach their semiclassical WKB analogs in the large action limit. The corresponding bipolar quantum trajectories, as defined in the usual Bohmian mechanical formulation, are classical-like and well-behaved, even when Psi has many nodes, or is wildly oscillatory. A modification for discontinuous potential stationary stattering states was presented in a second paper [J. Chem. Phys. 124 034115 (2006)], whose generalization for continuous potentials is given here. The result is an exact quantum scattering methodology using classical trajectories. For additional convenience in handling the tunneling case, a constant velocity trajectory version is also developed.Comment: 16 pages and 14 figure

    Centrifugal quantum states of neutrons

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    We propose a method for observation of the quasi-stationary states of neutrons, localized near the curved mirror surface. The bounding effective well is formed by the centrifugal potential and the mirror Fermi-potential. This phenomenon is an example of an exactly solvable "quantum bouncer" problem that could be studied experimentally. It could provide a promising tool for studying fundamental neutron-matter interactions, as well as quantum neutron optics and surface physics effects. We develop formalism, which describes quantitatively the neutron motion near the mirror surface. The effects of mirror roughness are taken into account.Comment: 13 pages, 10 figure

    Anomalous far infrared monochromatic transmission through a film of type-II superconductor in magnetic field

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    Anomalous far infrared monochromatic transmission through a lattice of Abrikosov vortices in a type-II superconducting film is found and reported. The transmitted frequency corresponds to the photonic mode localized by the defects of the Abrokosov lattice. These defects are formed by extra vortices placed out of the nodes of the ideal Abrokosov lattice. The extra vortices can be pinned by crystal lattice defects of a superconductor. The corresponding frequency is studied as a function of magnetic field and temperature in the framework of the Dirac-type two-band model. While our approach is valid for all type-II superconductors, the specific calculations have been performed for the YBa2_{2}Cu3_{3}O7δ_{7-\delta} (YBCO). The control of the transmitted frequency by varying magnetic field and/or temperature is analyzed. It is suggested that found anomalously transmitted localized mode can be utilized in the far infrared monochromatic filters.Comment: 9 pages, 2 figure

    A Life-Cycle Analysis of the Greenhouse Gas Emissions of Corn-Based Ethanol

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    1. Introduction pg. 1 2. Review of the Scientific Papers, Technical Reports, Data Sets, and Other Information that have Become Available Since 2010 and Relate to Current Emissions Levels in Each Emissions Category pg. 9 3. Current GHG Emission Values for Each Emissions Source Category pg. 88 4. Projected GHG LCA Emissions Values for a Business-As-Usual Scenario and a Building-Blocks Scenario for Corn Ethanol in 2022 pg. 15

    A Life-Cycle Analysis of the Greenhouse Gas Emissions of Corn-Based Ethanol

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    1. Introduction pg. 1 2. Review of the Scientific Papers, Technical Reports, Data Sets, and Other Information that have Become Available Since 2010 and Relate to Current Emissions Levels in Each Emissions Category pg. 9 3. Current GHG Emission Values for Each Emissions Source Category pg. 88 4. Projected GHG LCA Emissions Values for a Business-As-Usual Scenario and a Building-Blocks Scenario for Corn Ethanol in 2022 pg. 15

    Localization of a 64-kDa phosphoprotein in the lumen between the outer and inner envelopes of pea chloroplasts

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    The identification and localization of a marker protein for the intermembrane space between the outer and inner chloroplast envelopes is described. This 64-kDa protein is very rapidly labeled by [γ-32P]ATP at very low (30 nM) ATP concentrations and the phosphoryl group exhibits a high turnover rate. It was possible to establish the presence of the 64-kDa protein in this plastid compartment by using different chloroplast envelope separation and isolation techniques. In addition comparison of labeling kinetics by intact and hypotonically lysed pea chloroplasts support the localization of the 64-kDa protein in the intermembrane space. The 64-kDa protein was present and could be labeled in mixed envelope membranes isolated from hypotonically lysed plastids. Mixed envelope membranes incorporated high amounts of 32P from [γ-32P]ATP into the 64-kDa protein, whereas separated outer and inner envelope membranes did not show significant phosphorylation of this protein. Water/Triton X-114 phase partitioning demonstrated that the 64-kDa protein is a hydrophilic polypeptide. These findings suggest that the 64-kDa protein is a soluble protein trapped in the space between the inner and outer envelope membranes. After sonication of mixed envelope membranes, the 64-kDa protein was no longer present in the membrane fraction, but could be found in the supernatant after a 110000 × g centrifugation

    Atomic effects in astrophysical nuclear reactions

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    Two models are presented for the description of the electron screening effects that appear in laboratory nuclear reactions at astrophysical energies. The two-electron screening energy of the first model agrees very well with the recent LUNA experimental result for the break-up reaction He3(He3,2p)He4% He3(He3,2p)He^{4}, which so far defies all available theoretical models. Moreover, multi-electron effects that enhance laboratory reactions of the CNO cycle and other advanced nuclear burning stages, are also studied by means of the Thomas-Fermi model, deriving analytical formulae that establish a lower and upper limit for the associated screening energy. The results of the second model, which show a very satisfactory compatibility with the adiabatic approximation ones, are expected to be particularly useful in future experiments for a more accurate determination of the CNO astrophysical factors.Comment: 14 RevTex pages + 2 ps (revised) figures. Phys.Rev.C (in production
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