1,143 research outputs found

    A Merely Comic Conclusion: A Comparative Analysis of Xenophon’s Spartan Constitution

    Get PDF
    In this paper, I hope to do a small part to bridge the gap that has emerged in this scholarly debate between the historicist and Straussian views of Spartan society. To that end, this paper will analyze the Spartan Constitution according to the Straussian method. That is, I will engage in a close reading of the text, only referencing outside, secondary sources directly when necessary and appropriate. In other cases, their views will simply color this analysis and be referenced as supporting evidence in footnotes. Strauss chose to have only a superficial interaction with the existing scholarship at the time of publishing his essay, and I therefore believe it will be more beneficial to see what this approach would look like from the historicist perspective. When the same approach is taken, the heart of both camps’ arguments will be exposed, allowing them to be more easily compared. The paper will begin with a reading exploring the themes of Xenophon’s work according to a historicist perspective. After a brief aside explaining and motivating the Straussian esoteric argument to a greater extent, the paper will move on to a similar close-reading of the Spartan Constitution, following Strauss’ essay where appropriate and extending his arguments where necessary. Through this process, the paper aims to show that the perceived separation between the historicist and Straussian interpretations appears to be much greater than it, in reality, is

    Exploiting multi-word units in history-based probabilistic generation

    Get PDF
    We present a simple history-based model for sentence generation from LFG f-structures, which improves on the accuracy of previous models by breaking down PCFG independence assumptions so that more f-structure conditioning context is used in the prediction of grammar rule expansions. In addition, we present work on experiments with named entities and other multi-word units, showing a statistically significant improvement of generation accuracy. Tested on section 23 of the PennWall Street Journal Treebank, the techniques described in this paper improve BLEU scores from 66.52 to 68.82, and coverage from 98.18% to 99.96%

    Ab initio energy loss spectra of Si and Ge nanowires

    Get PDF
    We report an ab initio investigation of fast electron energy-loss probability in silicon and germanium nanowires. Computed energy loss spectra are characterized by a strong enhancement of the direct interband transition peak at low energy, in good agreement with experimental data. Our calculations predict an important diameter dependence of the bulk volume plasmon peak for very thin wires which is consistent with the blue shift observed experimentally in thicker wires

    Effect of oxidant type on the chemiluminescence intensity from the reaction of tris(2,2’-biyridyl)ruthenium(III) with various organic acids

    Full text link
    An investigation into the chemiluminescence of fourteen organic acids and tris(2,2′-bipyridyl)ruthenium(II) was undertaken. Particular emphasis was placed upon the method of production of the reagent, tris(2,2′-bipyridyl)ruthenium(III), with cerium(IV) sulfate, potassium permanganate, lead dioxide and electrochemical generation. Analytically useful chemiluminescence was observed when Ce(IV) or potassium permanganate were employed as oxidants. The kinetics of analyte oxidation was related to the intensity of the chemiluminescence emission, which increased by three orders of magnitude for tartaric acid after 40 h of oxidation

    Electrochemically tuneable multi-colour electrochemiluminescence using a single emitter

    Get PDF
    A single starting component electrochemiluminescence system from which red, green, blue or white emission can be obtained, depending on the applied potential or the mode of the ECL experiment, is described. The convoluted ECL spectral responses observed at different potentials are readily explained using a 3D-ECL technique, where the ECL spectral profile is continuously monitored as a function of potential during voltammetric scanning. The 3D plots obtained using this technique implicate cross-annihilation ECL reactions involving the complex itself and stable products resulting from its electrolysis. Combining this information with knowledge of the energetic requirements of the various reactions involved, suggests a mechanism involving traces of two emissive products, related to the loss of a methyl group from the triazole moiety. These products, while barely detectable electrochemically, are sufficiently emissive to influence and even dominate the ECL emission under some conditions

    Close-Packed Arrangements of Flat-On Free-Base Porphyrins Driven by van der Waals Epitaxy

    Get PDF
    The functionality of low dimensional phases of porphyrins in optical, chemical, electrical, and multimodal combinational devices is strictly related to the control of molecular orientation within the produced solid layers. A promising strategy to drive the growth of adlayers with predictable structural properties relies on the template effect exerted by the substrate. Tetraphenyl porphyrins, being disc-shaped objects, can be adsorbed on a crystal surface by taking on different geometries. An edge-on configuration is adopted when the interactions among molecules overtake those between molecules and substrate, whereas a flat-on configuration is adopted when molecule-substrate interaction is dominant, with the weaker intermolecular interaction driving a close-packed geometry in the adlayer. For this latter reason, square and/or hexagonal lattice symmetries of physisorbed porphyrin layers are disclosed on highly interacting metal substrates such as Au(111). Unfortunately, metal substrates modify the intrinsic properties of porphyrins by suppressing many of their functionalities. To overcome this drawback, here we report the selective growth of porphyrins in a flat-on arrangement on the chiral (110) cleavage surface of the mixed molecular organic crystal formed by 2,5-diketopiperazine and fumaric acid in a 1:1 mole ratio. The energetic advantage ensured by the interaction with the insulating substrate drives the prevalent formation of domains with a square symmetry, which is retained from monolayer to multilayers. However, rare domains with a hexagonal symmetry are revealed and analyzed by high-resolution scanning probe microscopic techniques. The experimental structural analysis performed at the nanoscale, combined with ab initio calculations, allowed us to demonstrate that the molecular architectures we found arise from the simultaneous fulfillment of site adsorption energy maximization driven by peculiar molecular motifs of the selected substrate, close-packing criteria, and epitaxial locking to the substrate surface by weak van der Waals interactions

    Chemiluminescence from reactions with bis-cyclometalated iridium complexes in acidic aqueous solution

    Full text link
    Chemical reactions between certain bis-cyclometalated iridium complexes, cerium(IV) and organic reducing agents in aqueous solution produce an emission of light which in some cases is more intense than that from analogous reactions with conventional ruthenium-based reagents, thus providing a new avenue for chemically-initiated luminescence detection.<br /

    Optical fingerprints of Si honeycomb chains and atomic gold wires on the Si (111)-(5× 2)-Au surface

    Get PDF
    The intensively studied Si(111)-(5×2)-Au surface is reexamined using reflectance anisotropy spectroscopy and density functional theory simulations. We identify distinctive spectral features relating directly to local structural motifs such as Si honeycomb chains and atomic gold wires that are commonly found on Au-reconstructed vicinal Si(111) surfaces. Optical signatures of chain dimerization, responsible for the observed (×2) periodicity, are identified. The optical response, together with STM simulations and first-principles total-energy calculations, exclude the new structure proposed very recently based on the reflection high-energy electron diffraction technique analysis of Abukawa and Nishigaya [ Phys. Rev. Lett. 110 036102 (2013)] and provide strong support for the Si honeycomb chain with the triple Au chain model of Erwin et al. [ Phys. Rev. B 80 155409 (2009)]. This is a promising approach for screening possible models of complex anisotropic surface structures
    • …
    corecore