635 research outputs found
Letter, John G. Nicolay to James P. Foster et al., February 5, 1887
This handwritten letter, dated February 5, 1887, is written from John G. Nicolay to James P. Foster et al. expressing his thanks for the invitation to attend the first annual dinner of the Republican Club of New York City and sends his regrets.https://scholarsjunction.msstate.edu/fvw-manuscripts-original-manuscripts/1176/thumbnail.jp
Electron-phonon coupling and its evidence in the photoemission spectra of lead
We present a detailed study on the influence of strong electron-phonon
coupling to the photoemission spectra of lead. Representing the strong-coupling
regime of superconductivity, the spectra of lead show characteristic features
that demonstrate the correspondence of physical properties in the normal and
the superconducting state, as predicted by the Eliashberg theory. These
features appear on an energy scale of a few meV and are accessible for
photoemission only by using modern spectrometers with high resolution in energy
and angle.Comment: 4 pages, 4 figures, accepted for publication in Phys. Rev. Let
Functional modes of proteins are among the most robust ones
It is shown that a small subset of modes which are likely to be involved in
protein functional motions of large amplitude can be determined by retaining
the most robust normal modes obtained using different protein models. This
result should prove helpful in the context of several applications proposed
recently, like for solving difficult molecular replacement problems or for
fitting atomic structures into low-resolution electron density maps. Moreover,
it may also pave the way for the development of methods allowing to predict
such motions accurately.Comment: 4 pages, 5 figure
Conductive inks for inkjet printing based on composition of nanoparticles and organic silver salt
In this article, conductive inks for inkjet printing with high content of silver nanoparticles with the addition of organic silver salt and polymer additives are developed and investigated. Silver nanoparticles are shown to be stably dispersed in a solvent and the presence of a silver salt and a polymeric surfactant ensures the viscosity necessary for printing. A print of test images is performed using a laboratory inkjet printer equipped with an industrial small-droplet printhead followed by annealing of printed patterns at 150–250°C, and their structural and electrical properties are investigated. Simultaneous presence of polymer additives and silver salt is found to influence the structure of the forming conductive layer and the conducting properties
Spin polarization of the L-gap surface states on Au(111)
The electron spin polarization (ESP) of the L-gap surface states on Au(111)
is investigated theoretically by means of first-principles electronic-structure
and photoemission calculations. The surface states show a large spin-orbit
induced in-plane ESP which is perpendicular to the in-plane wavevector, in
close analogy to a two-dimensional electron gas with Rashba spin-orbit
interaction. The surface corrugation leads to a small ESP component normal to
the surface, being not reported so far. The surface-states ESP can be probed
qualitatively and quantitatively by spin- and angle-resolved photoelectron
spectroscopy, provided that the initial-state ESP is retained in the
photoemission process and not obscured by spin-orbit induced polarization
effects. Relativistic photoemission calculations provide detailed information
on what photoemission set-ups allow to conclude from the photoelectron ESP on
that of the surface states.Comment: 22 pages with 8 figure
Higher order contributions to Rashba and Dresselhaus effects
We have developed a method to systematically compute the form of Rashba- and
Dresselhaus-like contributions to the spin Hamiltonian of heterostructures to
an arbitrary order in the wavevector k. This is achieved by using the double
group representations to construct general symmetry-allowed Hamiltonians with
full spin-orbit effects within the tight-binding formalism. We have computed
full-zone spin Hamiltonians for [001]-, [110]- and [111]-grown zinc blende
heterostructures (D_{2d},C_{4v},C_{2v},C_{3v} point group symmetries), which
are commonly used in spintronics. After an expansion of the Hamiltonian up to
third order in k, we are able to obtain additional terms not found previously.
The present method also provides the matrix elements for bulk zinc blendes
(T_d) in the anion/cation and effective bond orbital model (EBOM) basis sets
with full spin-orbit effects.Comment: v1: 11 pages, 3 figures, 8 table
Adaptations in mitochondrial function parallel, but fail to rescue, the transition to severe hyperglycemia and hyperinsulinemia: a study in Zucker diabetic fatty rats.
Cross-sectional human studies have associated mitochondrial dysfunction to type 2 diabetes. We chose Zucker diabetic fatty (ZDF) rats as a model of progressive insulin resistance to examine whether intrinsic mitochondrial defects are required for development of type 2 diabetes. Muscle mitochondrial function was examined in 6-, 12-, and 19-week-old ZDF (fa/fa) and fa/+ control rats (n = 8-10 per group) using respirometry with pyruvate, glutamate, and palmitoyl-CoA as substrates. Six-week-old normoglycemic-hyperinsulinemic fa/fa rats had reduced mitochondrial fat oxidative capacity. Adenosine diphosphate (ADP)-driven state 3 and carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP)-stimulated state uncoupled (state u) respiration on palmitoyl-CoA were lower compared to controls (62.3 ± 9.5 vs. 119.1 ± 13.8 and 87.8 ± 13.3 vs. 141.9 ± 14.3 nmol O2/mg/min.). Pyruvate oxidation in 6-week-old fa/fa rats was similar to controls. Remarkably, reduced fat oxidative capacity in 6-week-old fa/fa rats was compensated for by an adaptive increase in intrinsic mitochondrial function at week 12, which could not be maintained toward week 19 (140.9 ± 11.2 and 57.7 ± 9.8 nmol O2/mg/min, weeks 12 and 19, respectively), whereas hyperglycemia had developed (13.5 ± 0.6 and 16.1 ± 0.3 mmol/l, weeks 12 and 19, respectively). This mitochondrial adaptation failed to rescue the progressive development of insulin resistance in fa/fa rats. The transition of prediabetes state toward advanced hyperglycemia and hyperinsulinemia was accompanied by a blunted increase in uncoupling protein-3 (UCP3). Thus, in ZDF rats insulin resistance develops progressively in the absence of mitochondrial dysfunction. In fact, improved mitochondrial capacity in hyperinsulinemic hyperglycemic rats does not rescue the progression toward advanced stages of insulin resistance
Atomic correlations in itinerant ferromagnets: quasi-particle bands of nickel
We measure the band structure of nickel along various high-symmetry lines of
the bulk Brillouin zone with angle-resolved photoelectron spectroscopy. The
Gutzwiller theory for a nine-band Hubbard model whose tight-binding parameters
are obtained from non-magnetic density-functional theory resolves most of the
long-standing discrepancies between experiment and theory on nickel. Thereby we
support the view of itinerant ferromagnetism as induced by atomic correlations.Comment: 4 page REVTeX 4.0, one figure, one tabl
Role of bulk and surface phonons in the decay of metal surface states
We present a comprehensive theoretical investigation of the electron-phonon
contribution to the lifetime broadening of the surface states on Cu(111) and
Ag(111), in comparison with high-resolution photoemission results. The
calculations, including electron and phonon states of the bulk and the surface,
resolve the relative importance of the Rayleigh mode, being dominant for the
lifetime at small hole binding energies. Including the electron-electron
interaction, the theoretical results are in excellent agreement with the
measured binding energy and temperature dependent lifetime broadening.Comment: 4 pages, 3 figure
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