300 research outputs found

    The mechanism of caesium intercalation of graphene

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    Properties of many layered materials, including copper- and iron-based superconductors, topological insulators, graphite and epitaxial graphene can be manipulated by inclusion of different atomic and molecular species between the layers via a process known as intercalation. For example, intercalation in graphite can lead to superconductivity and is crucial in the working cycle of modern batteries and supercapacitors. Intercalation involves complex diffusion processes along and across the layers, but the microscopic mechanisms and dynamics of these processes are not well understood. Here we report on a novel mechanism for intercalation and entrapment of alkali-atoms under epitaxial graphene. We find that the intercalation is adjusted by the van der Waals interaction, with the dynamics governed by defects anchored to graphene wrinkles. Our findings are relevant for the future design and application of graphene-based nano-structures. Similar mechanisms can also play a role for intercalation of layered materials.Comment: 8 pages, 7 figures in published form, supplementary information availabl

    Navika tjelesne aktivnosti kod autora koji su objavljivali u Hrvatskom časopisu za javno zdravstvo

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    Navike se mogu definirati kao stečeni oblik ponaĆĄanja. Navike nastaju viĆĄestrukim, viĆĄegodiĆĄnjim, ponavljanjem odgovarajućih pokreta ili radnji. Postoje razne vrste navika npr. navike ponaĆĄanja, higijenske navike, radne navike itd. Neke od njih su pozitivne, a neke negativne. Tjelesna aktivnost je primjer pozitivne navike, koja pridonosi poboljĆĄanju psiho-fizičkog stanja čovjeka, te je stog vrlo vaĆŸna u primarnoj prevenciji niza kroničnih i akutnih bolesti. Da bi se stvorila navika redovitog tjelesnog vjeĆŸbanja potrebno je, unatoč fizičkom zamoru koji proizlazi iz same aktivnosti, ponavljati odgovarajuće vjeĆŸbe ili aktivnosti iz dana u dan, iz godine u godinu. Kada organizam počne prepoznavati umor u vrijeme treninga, a pogotovo nakon treninga, kao vrhunac ugode, tada moĆŸete biti sigurni da ste ovisnik o jednoj pozitivnoj navici- tjelesnoj aktivnosti.

    Beam test performance of a prototype module with Short Strip ASICs for the CMS HL-LHC tracker upgrade

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    The Short Strip ASIC (SSA) is one of the four front-end chips designed for the upgrade of the CMS Outer Tracker for the High Luminosity LHC. Together with the Macro-Pixel ASIC (MPA) it will instrument modules containing a strip and a macro-pixel sensor stacked on top of each other. The SSA provides both full readout of the strip hit information when triggered, and, together with the MPA, correlated clusters called stubs from the two sensors for use by the CMS Level-1 (L1) trigger system. Results from the first prototype module consisting of a sensor and two SSA chips are presented. The prototype module has been characterized at the Fermilab Test Beam Facility using a 120 GeV proton beam

    Test beam performance of a CBC3-based mini-module for the Phase-2 CMS Outer Tracker before and after neutron irradiation

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    The Large Hadron Collider (LHC) at CERN will undergo major upgrades to increase the instantaneous luminosity up to 5–7.5×1034^{34} cm−2^{-2}s−1^{-1}. This High Luminosity upgrade of the LHC (HL-LHC) will deliver a total of 3000–4000 fb-1 of proton-proton collisions at a center-of-mass energy of 13–14 TeV. To cope with these challenging environmental conditions, the strip tracker of the CMS experiment will be upgraded using modules with two closely-spaced silicon sensors to provide information to include tracking in the Level-1 trigger selection. This paper describes the performance, in a test beam experiment, of the first prototype module based on the final version of the CMS Binary Chip front-end ASIC before and after the module was irradiated with neutrons. Results demonstrate that the prototype module satisfies the requirements, providing efficient tracking information, after being irradiated with a total fluence comparable to the one expected through the lifetime of the experiment

    Search for invisible decays of the Higgs boson produced via vector boson fusion in proton-proton collisions at root s=13 TeV

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    Search for invisible decays of the Higgs boson produced via vector boson fusion in proton-proton collisions at s\sqrt{s} = 13 TeV