25,061 research outputs found

    Working with Bill Kruskal: From 1950 Onward

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    Discussion of ``The William Kruskal Legacy: 1919--2005'' by Stephen E. Fienberg, Stephen M. Stigler and Judith M. Tanur [arXiv:0710.5063]Comment: Published in at http://dx.doi.org/10.1214/088342306000000385 the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

    Proton-transport catalysis, proton abstraction, and proton exchange in HF+HOC⁺ and H₂O+HOC⁺ and analogous deuterated reactions

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    Classical simulations of the reactions of HF and H₂O with HOC⁺ have been carried out on interpolatedab initiopotential energy surfaces. Rearrangement (X+HOC⁺→OCH⁺+X), abstraction (X+HOC⁺→XH⁺+OC), (X=HF or H₂O), exchange (e.g., DY+HOC⁺→HY+DOC⁺), and exchange-rearrangement (e.g., DY+HOC⁺→OCD⁺+YH) (Y=F or HO or DO) reactions are observed. However, the abstraction reaction is dominant for both the HF+HOC⁺ and H₂O+HOC⁺ systems

    Integrable nonlinear field equations and loop algebra structures

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    We apply the (direct and inverse) prolongation method to a couple of nonlinear Schr{\"o}dinger equations. These are taken as a laboratory field model for analyzing the existence of a connection between the integrability property and loop algebras. Exploiting a realization of the Kac-Moody type of the incomplete prolongation algebra associated with the system under consideration, we develop a procedure with allows us to generate a new class of integrable nonlinear field equations containing the original ones as a special case.Comment: 13 pages, latex, no figures

    Comment on "Freezing by heating in a driven mesoscopic system"

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    We point out that the phenomenon ``heating by freezing'' discovered in nonequilibrium simulations by Helbing, et al. (PRL 84, 1240 (2000)) extends to equilibrium systems as well. We argue that such reentrant fluctuation-driven freezing can, for example, be realized in two-dimensional colloidal systems subjected to a one-dimensional periodic potential.Comment: 4 RevTeX pg

    Examining the Relationship between Emotion Perception and Bullying: A Proposal

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    Bullying and aggressive behaviors have adverse effects on many children. Violent behavior among children occurs most commonly in the school setting and may lead to negative emotional outcomes later in life (Kub & Feldman, 2015). According to a study conducted by Baroncelli et al. (2014), boys who have been found to be high in aggression have a difficult time perceiving relevant social cues such as fear and anger. However, boys were prone to frequently identify happiness and fear in faces when a different emotion was expressed. For girls, Baroncelli and colleagues did not find any significant relationships. The purpose of this paper was to conceptually replicate the research of Baroncelli et al. (2014), which was originally done in Italy. For my study, I plan on using children in the United States to determine if the ability to perceive emotion predicts aggression. Participants will be recruited from Hyde Park Middle School in Las Vegas, Nevada and will consist of approximately 1,100 male and female students. The Aggression Scale (Orpinas & Frankowski, 2001) and the Diagnostic Analysis of Nonverbal Accuracy –2 (DANVA2; Nowicki, 2013; Nowicki & Duke, 1994) will be completed online and will take approximately 30 minutes to complete. In order to determine if there is a relationship between aggression and emotion perception, I will calculate the correlation between the DANVA and the Aggression Scale

    Graphene tests of Klein phenomena

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    Graphene is characterized by chiral electronic excitations. As such it provides a perfect testing ground for the production of Klein pairs (electron/holes). If confirmed, the standard results for barrier phenomena must be reconsidered with, as a byproduct, the accumulation within the barrier of holes.Comment: 8 page

    Quantum Indistinguishability in Chemical Reactions

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    Quantum indistinguishability plays a crucial role in many low-energy physical phenomena, from quantum fluids to molecular spectroscopy. It is, however, typically ignored in most high temperature processes, particularly for ionic coordinates, implicitly assumed to be distinguishable, incoherent and thus well-approximated classically. We explore chemical reactions involving small symmetric molecules, and argue that in many situations a full quantum treatment of collective nuclear degrees of freedom is essential. Supported by several physical arguments, we conjecture a "Quantum Dynamical Selection" (QDS) rule for small symmetric molecules that precludes chemical processes that involve direct transitions from orbitally non-symmetric molecular states. As we propose and discuss, the implications of the Quantum Dynamical Selection rule include: (i) a differential chemical reactivity of para- and ortho-hydrogen, (ii) a mechanism for inducing inter-molecular quantum entanglement of nuclear spins, (iii) a new isotope fractionation mechanism, (iv) a novel explanation of the enhanced chemical activity of "Reactive Oxygen Species", (v) illuminating the importance of ortho-water molecules in modulating the quantum dynamics of liquid water, (vi) providing the critical quantum-to-biochemical linkage in the nuclear spin model of the (putative) quantum brain, among others.Comment: 12 pages, 5 figures. Clarified presentation and figure
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