9,949 research outputs found
Performing Messiaen’s Organ Music: 66 Masterclasses by Jon Gillock
Benitez reviews Gillock\u27s 2010 work.
Gillock, Jon. Performing Messiaen’s Organ Music: 66 Masterclasses. Bloomington, IN:Indiana University Press, 2010.
ISBN 978-0-253-35373-3
Next-to-Leading Order Corrections to Single Top Quark Production and Decay at the Tevatron: 2. -channel Process
We present a study of the -channel mode of single top quark production at
the upgraded Tevatron collider, including the next-to-leading order
(NLO) QCD corrections to the production and the decay of a single top quark.
The narrow width approximation was adopted in order to preserve the spin of the
top quark in its production and decay. We discuss the effects of different
contributions on the inclusive cross section as well as various
kinematic distributions after imposing the relevant cuts to select -channel
single top signal events.Comment: 46 pages, 47 figures. One typo in LaTeX source file is correcte
Two Metals Are Better Than One in the Gold Catalyzed Oxidative Heteroarylation of Alkenes
We present a detailed study of the mechanism for oxidative heteroarylation, based on DFT calculations and experimental observations. We propose binuclear Au(II)–Au(II) complexes to be key intermediates in the mechanism for gold catalyzed oxidative heteroarylation. The reaction is thought to proceed via a gold redox cycle involving initial oxidation of Au(I) to binuclear Au(II)–Au(II) complexes by Selectfluor, followed by heteroauration and reductive elimination. While it is tempting to invoke a transmetalation/reductive elimination mechanism similar to that proposed for other transition metal complexes, experimental and DFT studies suggest that the key C–C bond forming reaction occurs via a bimolecular reductive elimination process (devoid of transmetalation). In addition, the stereochemistry of the elimination step was determined experimentally to proceed with complete retention. Ligand and halide effects played an important role in the development and optimization of the catalyst; our data provides an explanation for the ligand effects observed experimentally, useful for future catalyst development. Cyclic voltammetry data is presented that supports redox synergy of the Au···Au aurophilic interaction. The monometallic reductive elimination from mononuclear Au(III) complexes is also studied from which we can predict a ~ 15 kcal/mol advantage for bimetallic reductive elimination
Inhomogenized sudden future singularities
We find that sudden future singularities may also appear in spatially
inhomogeneous Stephani models of the universe. They are temporal pressure
singularities and may appear independently of the spatial finite density
singularities already known to exist in these models. It is shown that the main
advantage of the homogeneous sudden future singularities which is the
fulfillment of the strong and weak energy conditions may not be the case for
inhomogeneous models.Comment: REVTEX 4, 5 pages, no figures, a discussion of the most general case
include
Freeform Optical Surfaces: Report from OSA's First Incubator Meeting
Just as business incubator programs are designed to support the development of fledgling companies, OSA?s new incubator meeting series is structured to encourage the growth of exciting new areas within optics. The first one was devoted to the topic of freeform optics-a field that is actively evolving due to recent technological advances
Berry curvature and Hall viscosities in an anisotropic Dirac semimetal
We investigate parity-odd nondissipative transport in an anisotropic Dirac semimetal in two spatial dimensions. The analysis is relevant for interacting electronic systems with merging Dirac points at charge neutrality. For such systems the dispersion relation is relativistic in one direction and nonrelativistic in the other. We give a proposal of how to calculate the Berry curvature for this system and use it to derive more than one odd viscosities, in contrast to rotationally invariant systems. We observe that in such a model the odd part of viscosity tensor is parametrized by two independent transport coefficients and one that is identically zero
Magnetic microscopy of topologically protected homochiral domain walls in an ultrathin perpendicularly magnetized Co film
Next-generation concepts for solid-state memory devices are based on
current-driven domain wall propagation, where the wall velocity governs the
device performance. It has been shown that the domain wall velocity and the
direction of travel is controlled by the nature of the wall and its chirality.
This chirality is attributed to effects emerging from the lack of inversion
symmetry at the interface between a ferromagnet and a heavy metal, leading to
an interfacial Dzyaloshinskii-Moriya interaction that can control the shape and
chirality of the magnetic domain wall. Here we present direct imaging of domain
walls in Pt/Co/AlO films using Lorentz transmission electron microscopy,
demonstrating the presence of homochiral, and thus topologically protected,
N\'{e}el walls. Such domain walls are good candidates for dense data storage,
bringing the bit size down close to the limit of the domain wall width
- …