1,686 research outputs found

    Orientation-dependent binding energy of graphene on palladium

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    Using density functional theory calculations, we show that the binding strength of a graphene monolayer on Pd(111) can vary between physisorption and chemisorption depending on its orientation. By studying the interfacial charge transfer, we have identified a specific four-atom carbon cluster that is responsible for the local bonding of graphene to Pd(111). The areal density of such clusters varies with the in-plane orientation of graphene, causing the binding energy to change accordingly. Similar investigations can also apply to other metal substrates, and suggests that physical, chemical, and mechanical properties of graphene may be controlled by changing its orientation.Comment: 5 pages, 6 figure

    OpenGM: A C++ Library for Discrete Graphical Models

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    OpenGM is a C++ template library for defining discrete graphical models and performing inference on these models, using a wide range of state-of-the-art algorithms. No restrictions are imposed on the factor graph to allow for higher-order factors and arbitrary neighborhood structures. Large models with repetitive structure are handled efficiently because (i) functions that occur repeatedly need to be stored only once, and (ii) distinct functions can be implemented differently, using different encodings alongside each other in the same model. Several parametric functions (e.g. metrics), sparse and dense value tables are provided and so is an interface for custom C++ code. Algorithms are separated by design from the representation of graphical models and are easily exchangeable. OpenGM, its algorithms, HDF5 file format and command line tools are modular and extendible

    Hydrogen molecule in a magnetic field: The lowest states of the Pi manifold and the global ground state of the parallel configuration

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    The electronic structure of the hydrogen molecule in a magnetic field is investigated for parallel internuclear and magnetic field axes. The lowest states of the Π\Pi manifold are studied for spin singlet and triplet(Ms=−1)(M_s = -1) as well as gerade and ungerade parity for a broad range of field strengths 0≤B≤100a.u.0 \leq B \leq 100 a.u. For both states with gerade parity we observe a monotonous decrease in the dissociation energy with increasing field strength up to B=0.1a.u.B = 0.1 a.u. and metastable states with respect to the dissociation into two H atoms occur for a certain range of field strengths. For both states with ungerade parity we observe a strong increase in the dissociation energy with increasing field strength above some critical field strength BcB_c. As a major result we determine the transition field strengths for the crossings among the lowest 1Σg^1\Sigma_g, 3Σu^3\Sigma_u and 3Πu^3\Pi_u states. The global ground state for B≲0.18a.u.B \lesssim 0.18 a.u. is the strongly bound 1Σg^1\Sigma_g state. The crossings of the 1Σg^1\Sigma_g with the 3Σu^3\Sigma_u and 3Πu^3\Pi_u state occur at B≈0.18B \approx 0.18 and B≈0.39a.u.B \approx0.39 a.u., respectively. The transition between the 3Σu^3\Sigma_u and 3Πu^3\Pi_u state occurs at B≈12.3a.u.B \approx 12.3 a.u. Therefore, the global ground state of the hydrogen molecule for the parallel configuration is the unbound 3Σu^3\Sigma_u state for 0.18≲B≲12.3a.u.0.18 \lesssim B \lesssim 12.3 a.u. The ground state for B≳12.3a.u.B \gtrsim 12.3 a.u. is the strongly bound 3Πu^3\Pi_u state. This result is of great relevance to the chemistry in the atmospheres of magnetic white dwarfs and neutron stars.Comment: submitted to Physical Review

    Contacting single bundles of carbon nanotubes with alternating electric fields

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    Single bundles of carbon nanotubes have been selectively deposited from suspensions onto sub-micron electrodes with alternating electric fields. We explore the resulting contacts using several solvents and delineate the differences between Au and Ag as electrode materials. Alignment of the bundles between electrodes occurs at frequencies above 1 kHz. Control over the number of trapped bundles is achieved by choosing an electrode material which interacts strongly with the chemical functional groups of the carbon nanotubes, with superior contacts being formed with Ag electrodes.Comment: 4 pages, RevTe

    Self-regulation of time management: mental contrasting with implementation intentions

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    Mental contrasting with implementation intentions (MCII) has been found to improve self-regulation across many life domains. The present research investigates whether MCII can benefit time management. In Study 1, we asked students to apply MCII to a pressing academic problem and assessed how they scheduled their time for the upcoming week. MCII participants scheduled more time than control participants who in their thoughts either reflected on similar contents using different cognitive procedures (content-control group) or applied the same cognitive procedures on different contents (format-control group). In Study 2, students were taught MCII as a metacognitive strategy to be used on any upcoming concerns of the subsequent week. As compared with the week prior to the training, students in the MCII (vs. format control) condition improved in self-reported time management. In Study 3, MCII (vs. format control) helped working mothers who enrolled in a vocational business program to attend classes more regularly. The findings suggest that performing MCII on one's everyday concerns improves time management

    Genomic diversity and characterization of lungwoms

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    Analysis of the genetic diversity of organisms plays an important role in research of related species and clinical applications. Lungworms (Dictyocaulus spp) have been identified in many species of ruminants. This study aimed to investigate the genomic variations of lungworms species, which could potentially lead to practical control methods and therapeutics in the distinct species of lungworms. To determine genetic relatedness, lungworm DNA was isolated from white-tailed deer (Odocoileus virginianus), New Zealand Red deer (Cervus elaphus), Louisiana cattle (Bos taurus), Mississippi cattle, and Wisconsin cattle and extracted, amplified through polymerase chain reaction (PCR), and then visualized using agarose gel electrophoresis. Currently, the PCR protocol has been unreliable and protocols are being designed to give more consistent results. At the moment, different approaches are being used to get the PCR to run and be able to get consistent results when amplifying. Once the PCR is fully functional, the next steps will be DNA cloning and sequencing for further investigation of the different species.https://openriver.winona.edu/urc2019/1005/thumbnail.jp

    Identification of a novel retroviral gene unique to human immunodeficiency virus type 2 and simian immunodeficiency virus SIVMAC

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    Human and simian immunodeficiency-associated retroviruses are extraordinarily complex, containing at least five genes, tat, art, sor, R, and 3' orf, in addition to the structural genes gag, pol, and env. Recently, nucleotide sequence analysis of human immunodeficiency virus type 2 (HIV-2) and simian immunodeficiency virus SIVMAC revealed the existence of still another open reading frame, termed X, which is highly conserved between these two viruses but absent from HIV-1. In this report, we demonstrate for the first time that the X open reading frame represents a functional retroviral gene in both HIV-2 and SIVMAC and that it encodes a virion-associated protein of 14 and 12 kilodaltons, respectively. We also describe the production of recombinant TrpE/X fusion proteins in Escherichia coli and show that sera from some HIV-2-infected individuals specifically recognize these proteins
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