cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Impurity-assisted tunneling magnetoresistance under weak magnetic field
Creators: name: Txoperena, Oihana
name: Song, Yang
name: Qing, Lan
name: Gobbi, Marco
name: Hueso, Luis E.
name: Dery, Hanan
name: Casanova, Fèlix
Publisher: name: arXiv
Year: 2014
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Injection of spins into semiconductors is essential for the integration of the spin functionality into conventional electronics. Insulating layers are often inserted between ferromagnetic metals and semiconductors for obtaining an efficient spin injection, and it is therefore crucial to distinguish between signatures of electrical spin injection and impurity-driven effects in the tunnel barrier. Here we demonstrate an impurity-assisted tunneling magnetoresistance effect in nonmagnetic-insulator-nonmagnetic and ferromagnetic-insulator-nonmagnetic tunnel barriers. In both cases, the effect reflects on/off switching of the tunneling current through impurity channels by the external magnetic field. The reported effect, which is universal for any impurity-assisted tunneling process, finally clarifies the controversy of a widely used technique that employs the same ferromagnetic electrode to inject and detect spin accumulation.
description: 5 pages, 3 figures, Supplemental Material
The mapping problem in coarse-grained modelling of biomolecules
Creators: name: Giulini, Marco
Publisher: name: Universit� degli studi di Trento
Year: 2022

description: Low-resolution, coarse-grained models are powerful computational tools to investigate the behavior of biological systems over time and length scales that are not accessible to all-atom Molecular Dynamics simulations. While several algorithms exist that aim at constructing accurate coarse-grained potentials, few works focus on the choice of the reduced representation, or mapping, to be employed to describe the high-resolution system with a lower number of degrees of freedom. This thesis proposes a series of approaches to investigate and characterise the representation problem in coarse-grained modelling of proteins. This is achieved by employing a collection of diverse methods, including statistical mechanics, machine learning algorithms and information-theoretical tools. The central mathematical object of this work is the mapping entropy, a Kullback-Leibler divergence that measures the intrinsic quality of a given reduced representation. When this quantity is minimised, we obtain the maximally informative coarse-grained mappings of a biomolecule, which cover the structure with an uneven level of detail. Tests conducted over a set of well-known proteins show that regions preserved with high probability are often related to important functional mechanisms of the molecule. Applications of the mapping entropy outside of the field of structural biology show promising results, leading to the identification of those combinations of features that retain the maximum amount of information about the high-resolution system. Additionally, a purely structural notion of scalar product and distance between coarse-grained mappings is introduced, which allow to analyse the metric and topological properties of the mapping space. The thorough exploration of such space leads to the discovery of qualitatively different reduced representations of the biomolecule of interest.
Jwst e le super fabbriche di polveri stellari
Creators: Chiara Badia
Publisher: name: Media Inaf
Year: 2023

Scovate daI telescopio spaziale James Webb grandi quantità di polvere nei getti di due supernove di tipo II a 22 milioni di anni luce da noi. Lo studio cerca di indagare sull'origine della polvere cosmica che ha formato i pianeti e l'Universo primordiale, e la grande massa trovata nelle due supernove supporta la teoria secondo cui queste hanno avuto un ruolo chiave nella produzione di polvere nell'universo primordiale
Trivial and inverted Dirac bands and emergence of quantum spin Hall states in graphene on transition-metal dichalcogenides
Creators: name: Gmitra, Martin
name: Kochan, Denis
name: Högl, Petra
name: Fabian, Jaroslav
Publisher: name: Universität Regensburg
Year: 2016
Subjects: subject: ;
subject: 530 Physik

description: Proximity orbital and spin-orbital effects of graphene on monolayer transition-metal dichalcogenides (TMDCs) are investigated from first-principles. The Dirac band structure of graphene is found to lie within the semiconducting gap of TMDCs for sulfides and selenides, while it merges with the valence band for tellurides. In the former case, the proximity-induced staggered potential gaps and spin-orbit couplings (all on the meV scale) of the Dirac electrons are established by fitting to a phenomenological effective Hamiltonian. While graphene on MoS2, MoSe2, and WS2 has a topologically trivial band structure, graphene on WSe2 exhibits inverted bands. Using a realistic tight-binding model we find topologically protected helical edge states for graphene zigzag nanoribbons on WSe2, demonstrating the quantum spin Hall effect. This model also features "half-topological states," which are protected against time-reversal disorder on one edge only.
Control of spin helix symmetry in semiconductor quantum wells by crystal orientation
Creators: name: Kammermeier, Michael
name: Wenk, Paul
name: Schliemann, John
Publisher: name: Universität Regensburg
Year: 2016
Subjects: subject: 500 Naturwissenschaften
subject: 530 Physik

description: We investigate the possibility of spin-preserving symmetries due to the interplay of Rashba and Dresselhaus spin-orbit coupling in n-doped zinc-blende semiconductor quantum wells of general crystal orientation. It is shown that a conserved spin operator can be realized if and only if at least two growth-direction Miller indices agree in modulus. The according spin-orbit field has in general both in-plane and out-of-plane components and is always perpendicular to the shift vector of the corresponding persistent spin helix. We also analyze higher-order effects arising from the Dresselhaus term, and the impact of our results on weak (anti)localization corrections.
A caccia di giganti freddi con Harps-N
Creators: Eleonora Ferroni
Publisher: name: Media Inaf
Year: 2023

Sfruttando le potenzialità dello spettrografo Harps-N al Tng, un gruppo di esperti a guida Inaf ha scovato cinque gioviani freddi in tre sistemi planetari: due di questi erano già noti, mentre tre sono nuove scoperte. Il gruppo ha utilizzato il metodo delle velocità radiali per cercare pianeti giganti gassosi freddi in quasi quaranta sistemi già noti per ospitare super-Terre e sub-Nettuniani. A cosa serve questa survey? Anche a studiare l'origine dei pianeti del Sistema solare
Graph states as ground states of two-body frustration-free Hamiltonians
Creators: name: Darmawan, Andrew S.
name: Bartlett, Stephen D.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Physics (quant-ph)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The framework of measurement-based quantum computation (MBQC) allows us to view the ground states of local Hamiltonians as potential resources for universal quantum computation. A central goal in this field is to find models with ground states that are universal for MBQC and that are also natural in the sense that they involve only two-body interactions and have a small local Hilbert space dimension. Graph states are the original resource states for MBQC, and while it is not possible to obtain graph states as exact ground states of two-body Hamiltonians here we construct two-body frustration-free Hamiltonians that have arbitrarily good approximations of graph states as unique ground states. The construction involves taking a two-body frustration-free model that has a ground state convertible to a graph state with stochastic local operations, then deforming the model such that its ground state is close to a graph state. Each graph state qubit resides in a subspace of a higher dimensional particle. This deformation can be applied to two-body frustration-free Affleck-Kennedy-Lieb-Tasaki (AKLT) models, yielding Hamiltonians that are exactly solvable with exact tensor network expressions for ground states. For the star-lattice AKLT model, the ground state of which is not expected to be a universal resource for MBQC, applying such a deformation appears to enhance the computational power of the ground state, promoting it to a universal resource for MBQC. Transitions in computational power, similar to percolation phase transitions, can be observed when Hamiltonians are deformed in this way. Improving the fidelity of the ground state comes at the cost of a shrinking gap. While analytically proving gap properties for these types of models is difficult in general, we provide a detailed analysis of the deformation of a spin-1 AKLT state to a linear graph state.
description: 16 pages, 5 figures, comments welcome; v2 published version
Conserved spin quantity in strained hole systems with Rashba and Dresselhaus spin-orbit coupling
Creators: name: Wenk, Paul
name: Kammermeier, Michael
name: Schliemann, John
Publisher: name: Universität Regensburg
Year: 2016
Subjects: subject: BAND-STRUCTURE; CYCLOTRON-RESONANCE; CONDUCTION-BAND; LIGHT-HOLE; SEMICONDUCTORS; WELLS; STATES; HELIX;
subject: 530 Physik

description: We derive an effective Hamiltonian for a (001)-confined quasi-two-dimensional hole gas in a strained zinc-blende semiconductor heterostructure including both Rashba and Dresselhaus spin-orbit coupling. In the presence of uniaxial strain along the < 110 > axes, we find a conserved spin quantity in the vicinity of the Fermi contours in the lowest valence subband. In contrast to previous works, this quantity meets realistic requirements for the Luttinger parameters. For more restrictive conditions, we even find a conserved spin quantity for vanishing strain, restricted to the vicinity of the Fermi surface.
Marte, in attesa d’acqua liquida
Creators: Maura Sandri
Publisher: name: Media Inaf
Year: 2023

Uno studio pubblicato su Science sostiene che, quando l’asse di rotazione di Marte si inclina a circa 35 gradi, la sua atmosfera diventa abbastanza densa da consentire al ghiaccio di sciogliersi ed erodere i canaloni che solcano le pendici dei crateri da impatto. Questo, secondo gli autori, si è probabilmente verificato ripetutamente negli ultimi milioni di anni, con l'evento più recente circa 630mila anni fa
Simulating Hydration of Lime cement Binders with HYMOSTRUCT Model
Creators: name: Zeng, Yu
name: Ye, Guang
Publisher: name: Zenodo
Year: 2022

description: Despite their superiorities in carbon sequestration ability and gas permeability, pure lime mortars are weak and fragile in early ages, as they usually gain strengths through long-term carbonation. Therefore, mixtures of slaked lime and Portland cement are preferred in masonry structures to balance sustainability and early-age mechanical performances. However, due to the lack of understanding in reaction kinetics, there is no reliable microstructure formation models for lime-cement binders, and the material design can only be carried out in an empirical approach. To bridge this gap, this research focuses on hydration, the dominant hardening mechanism in early ages, and empirically determines the hydration kinetics through the combined use of X-ray diffraction (XRD), thermogravimetric analyses (TG), and calorimetry. Based on experiment results, the HYMOSTRUCT model, which was originally developed for cement hydration, is further extended to lime-cement binders. In the extended model, spherical lime and cement clinker particles were firstly generated with laser diffraction test results of raw materials. Then the hydrations of four major phases (i.e., C3S, C2S, C3A and C4AF) were separately considered with basic hydration factors obtained through quantitative analyses of XRD results, and the hydration product was calculated as a uniformly distributed shell outside of cement clinker particles. The influence of slaked lime is interpreted in two aspects – increase in basic hydration rates and the change in cement clinker distribution. The model was finally compared with pore size distribution data obtained with mercury intrusion porosimetry (MIP) and could be used as the input for further carbonation simulation.
Cheilosia illustrata
Creators: name: MAZáNEK, Libor
name: VONIČKA, Pavel
name: PREISLER, JiřÍ
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Syrphidae
Cheilosia
Cheilosia illustrata

description: Cheilosia illustrata (Harris, 1780) Eurosibiřský druh. LokÁlně velmi hojný druh světlin a otevřených vlhčÍch ploch s vysokobylinnou vegetacÍ v lesnaté krajině. Larvy žijÍ v kořenech vysokých miřÍkovitých bylin (Apiaceae). Bukovec PR [3a]: 31.V.2003, 1 ♂ (SW). Kořenov [16a]: 12.VI.2005, 1 ♂; 13.VI.2005, 2 ♂♂. Tichá říčka PP [44]: 30.VII.-14.VIII.2004, 1 ♀ (YPT). U Kyselky [46]: 2.-20.VI.2006, 1 ♂ (MT).
description: Published as part of MAZáNEK, Libor, VONIČKA, Pavel & PREISLER, JiřÍ, 2009, Syrphidae (Diptera) of the Jizerské hory Mts and Frýdlant region (northern Bohemia, Czech Republic), pp. 3-46 in Sborník Severočeského Muzea 27 on page 35, DOI: 10.5281/zenodo.7153554
Universality and the QCD Anderson Transition
Creators: name: Giordano, Matteo
name: Kovacs, Tamas G.
name: Pittler, Ferenc
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the Anderson-type transition previously found in the spectrum of the QCD quark Dirac operator in the high temperature, quark-gluon plasma phase. Using finite size scaling for the unfolded level spacing distribution, we show that in the thermodynamic limit there is a genuine mobility edge, where the spectral statistics changes from Poisson to Wigner-Dyson statistics in a non-analytic way. We determine the correlation length critical exponent, $ν$, and find that it is compatible with that of the unitary Anderson model.
description: 4 pages, 5 figures
Glacial refugia and postglacial expansion of the alpine-prealpine plant species Polygala chamaebuxus
Creators: name: Reisch, Christoph
name: Windmaißer, Tobias
name: Kattari, Stefan
name: Heubel, Günther
Publisher: name: Universität Regensburg
Year: 2016
Subjects: subject: GENETIC-VARIATION; EUROPEAN ALPS; MOLECULAR EVIDENCE; SCOTS PINE; ICE AGES; COMPARATIVE PHYLOGEOGRAPHY; REPRODUCTIVE SUCCESS; POPULATION-STRUCTURE; PLEISTOCENE HISTORY; COLONIZATION ROUTES; AFLP; genetic variation; glacial relict; phylogeography; Polygala chamaebuxus
subject: 580 Pflanzen (Botanik)

description: The shrubby milkwort (Polygala chamaebuxus L.) is widely distributed in the Alps, but occurs also in the lower mountain ranges of Central Europe such as the Franconian Jura or the Bohemian uplands. Populations in these regions may either originate from glacial survival or from postglacial recolonization. In this study, we analyzed 30 populations of P.chamaebuxus from the whole distribution range using AFLP (Amplified Fragment Length Polymorphism) analysis to identify glacial refugia and to illuminate the origin of P.chamaebuxus in the lower mountain ranges of Central Europe. Genetic variation and the number of rare fragments within populations were highest in populations from the central part of the distribution range, especially in the Southern Alps (from the Tessin Alps and the Prealps of Lugano to the Triglav Massiv) and in the middle part of the northern Alps. These regions may have served, in accordance with previous studies, as long-term refugia for the glacial survival of the species. The geographic pattern of genetic variation, as revealed by analysis of molecular variance, Bayesian cluster analysis and a PopGraph genetic network was, however, only weak. Instead of postglacial recolonization from only few long-term refugia, which would have resulted in deeper genetic splits within the data set, broad waves of postglacial expansion from several short-term isolated populations in the center to the actual periphery of the distribution range seem to be the scenario explaining the observed pattern of genetic variation most likely. The populations from the lower mountain ranges in Central Europe were more closely related to the populations from the southwestern and northern than from the nearby eastern Alps. Although glacial survival in the Bohemian uplands cannot fully be excluded, P.chamaebuxus seems to have immigrated postglacially from the southwestern or central-northern parts of the Alps into these regions during the expansion of the pine forests in the early Holocene.
Persistent Spin Textures in Semiconductor Nanostructures
Creators: name: Schliemann, John
Publisher: name: Universität Regensburg
Year: 2016
Subjects: subject: 500 Naturwissenschaften
subject: 530 Physik

description: Device concepts in semiconductor spintronics make long spin lifetimes desirable, and the requirements put on spin control by schemes of quantum information processing are even more demanding. Unfortunately, due to spin-orbit coupling electron spins in semiconductors are generically subject to rather fast decoherence. In two-dimensional quantum wells made of zinc-blende semiconductors, however, the spin-orbit interaction can be engineered in such a way that persistent spin structures with extraordinarily long spin lifetimes arise even in the presence of disorder and imperfections. We review experimental and theoretical developments on this subject both for n-doped and p-doped structures, and we discuss possible device applications.
Holography for (1,0) theories in six dimensions
Creators: name: Gaiotto, Davide
name: Tomasiello, Alessandro
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: M-theory and string theory predict the existence of many six-dimensional SCFTs. In particular, type IIA brane constructions involving NS5-, D6- and D8-branes conjecturally give rise to a very large class of N=(1,0) CFTs in six dimensions. We point out that these theories sit at the end of RG flows which start from six-dimensional theories which admit an M-theory construction as a M5 stack transverse to $R^4/Z_k \times R$. The flows are triggered by Higgs branch expectation values and correspond to D6's opening up into transverse D8-branes via a Nahm pole. We find a precise correspondence between these CFT's and the AdS$_7$ vacua found in a recent classification in type II theories. Such vacua involve massive IIA regions, and the internal manifold is topologically $S^3$. They are characterized by fluxes for the NS three-form and RR two-form, which can be thought of as the near-horizon version of the NS5's and D6's in the brane picture; the D8's, on the other hand, are still present in the AdS$_7$ solution, in the form of an arbitrary number of concentric shells wrapping round $S^2$'s.
description: 32 pages, 11 figures. v2: extra citations, corrections to figures 2 and 10
Avvertimenti energetici dal Sole
Creators: Valentina Guglielmo
Publisher: name: Media Inaf
Year: 2023

Un forte brillamento solare è stato identificato e immortalato nella notte del 3 luglio dal Solar Dynamics Observatory, e visto anche da Parker Solar Probe. Si tratta di un evento significativo, ma non eccezionale: ne seguiranno altri, infatti, perché la nostra stella si sta avvicinando al picco di attività del ciclo corrente. Con un commento di Daniele Telloni dell'Inaf di Torino
LA SUCCESSIONE NELL�ATTIVIT� DI IMPRESA. ANALISI COMPARATA E INDAGINE SULLA (PRESUNTA) ESTRANEIT� DELLA CAUSA SOCIETATIS AL FENOMENO SUCCESSORIO
Creators: name: DE PAOLI AMBROSI, ROBERTA
Publisher: name: Universit� degli Studi di Milano
Year: 2015

description: The scope of this work is to provide a comparative analysis on the relationship between the Law of Successions and Corporate Law. In each legal system the Law of Succession and the Corporate Law goals diverge. The Law of Successions is focused on transfer and divide among all of his/her heirs the estate that a testator has acquired during his or her life. In contrast, Corporate Law concerns the concentration. The research takes into account the crucial role that family firms played in European area. In particular, family firms contribute significantly in the economic growing implying long-term stability. First, this thesis considers as a priority for European Union the fact that citizens must be able to organise in advance their succession, in particular with respect to mortis causa successions in a context of their increasing mobility. To show whether and how Corporate law diverges to the law of succession, I analyse some fixed limits to one?s testamentary freedom as the prohibition of testamentary contract/agreement (?patti successori?) or as the right to a compulsory portion. England legal system embraces the rule of the testamentary freedom. In contrast, French and the Italian legal system establish the prohibition of testamentary contract/agreement (?patti successori?), in addition to the right to a compulsory portion rule of restriction. However the French legal system enacted in 2001 and 2006 two reforms, which implied a significant deviation from these rules. The study of these limitations helped the research about the provisions under the articles of association because there are a number of ways in which company law and inheritance law can work together, though Company Law must not constitute the way to evade Succession Law.
A Solution to the Combinatorial Puzzle of Mayer's Virial Expansion
Creators: name: Tate, Stephen James
Publisher: name: arXiv
Year: 2014
Subjects: subject: Mathematical Physics (math-ph)
subject: Combinatorics (math.CO)
subject: FOS: Physical sciences
subject: FOS: Mathematics
subject: 82B21, 82B26, 82D05, 05C22

description: Mayer's second theorem in the context of a classical gas model allows us to write the coefficients of the virial expansion of pressure in terms of weighted two-connected graphs. Labelle, Leroux and Ducharme studied the graph weights arising from the one-dimensional hardcore gas model and noticed that the sum of these weights over all two-connected graphs with $n$ vertices is $-n(n-2)!$. This paper addresses the question of achieving a purely combinatorial proof of this observation.
description: 25 pages, 6 figures
Cheilosia lenis Becker 1894
Creators: name: MAZáNEK, Libor
name: VONIČKA, Pavel
name: PREISLER, JiřÍ
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Syrphidae
Cheilosia
Cheilosia lenis

description: Cheilosia lenis Becker, 1894 Druh znÁmý z mÍrného pÁsu Evropy. Často se vyskytuje na světlinÁch v nejrůznějšÍch, spÍše vlhčÍch lesÍch. Larvy žijÍ ve stoncÍch starčku Senecio fuchsii. Harta [8]: 12.V.2006, 1 ♀ (SW). Malá Strana PR [21]: 4.VI.2008, 1 ♀ (SW).
description: Published as part of MAZáNEK, Libor, VONIČKA, Pavel & PREISLER, JiřÍ, 2009, Syrphidae (Diptera) of the Jizerské hory Mts and Frýdlant region (northern Bohemia, Czech Republic), pp. 3-46 in Sborník Severočeského Muzea 27 on page 35, DOI: 10.5281/zenodo.7153554
Weak (anti)localization in tubular semiconductor nanowires with spin-orbit coupling
Creators: name: Kammermeier, Michael
name: Wenk, Paul
name: Schliemann, John
name: Heedt, Sebastian
name: Schäpers, Thomas
Publisher: name: Universität Regensburg
Year: 2016
Subjects: subject: 2D ELECTRON-GAS; INAS NANOWIRES; QUANTUM-WELLS; MAGNETORESISTANCE; ANTILOCALIZATION; HETEROSTRUCTURES; GROWTH; RINGS; FIELD; GAAS;
subject: 530 Physik

description: We compute analytically the weak (anti) localization correction to the Drude conductivity for electrons in tubular semiconductor systems of zinc-blende type. We include linear Rashba and Dresselhaus spin-orbit coupling (SOC) and compare wires of standard growth directions < 100 >, < 111 >, and < 110 >. The motion on the quasi-two-dimensional surface is considered diffusive in both directions: transversal as well as along the cylinder axis. It is shown that Dresselhaus and Rashba SOC similarly affect the spin relaxation rates. For the < 110 > growth direction, the long-lived spin states are of helical nature. We detect a crossover from weak localization to weak antilocalization depending on spin-orbit coupling strength as well as dephasing and scattering rate. The theory is fitted to experimental data of an undoped < 111 > InAs nanowire device which exhibits a top-gate-controlled crossover from positive to negative magnetoconductivity. Thereby, we extract transport parameters where we quantify the distinct types of SOC individually.
Formazione a sandwich per i piccoli pianeti
Creators: Jacopo Danieli
Publisher: name: Media Inaf
Year: 2023

Un team di ricercatori dell'Università di Warwick ha sviluppato una nuova interessante ipotesi su come potrebbero formarsi i pianeti di piccole dimensioni. Il team ha mostrato come due pianeti di dimensioni maggiori nel disco protoplanetario possano potenzialmente dare origine a un pianeta più piccolo tra di loro, definendo il processo "formazione a sandwich"
EXPLORING DETECTION LIMITS AND RESPONSE TIME SCALES OF CHEMIRESISTOR GAS SENSORS BASED ON CARBON NANOTUBE AND HYBRID LAYERS
Creators: name: RIGONI, FEDERICA
Publisher: name: Universit� degli Studi di Milano
Year: 2015

description: Crucial features in gas sensors for environmental monitoring are the gas sensitivity in the low ppb range and the ability to discriminate variations of a certain polluting gas from other interfering gases. Monitoring of ammonia gas concentrations is mandatory to reduce the hazard for human health and vegetation determined by the widespread use of ammonia derivatives as agricultural nitrogen fertilizers, industrial production and traffic. In particular, ammonia, besides being a toxic molecule is one of the main precursors of secondary fine particulate matter (PM10, PM2.5). Ammonia could hence be used as a local marker of secondary fine particulate formation, allowing indirect control of particulate emission sources. In spite of this urgency, the detection of NH3 concentrations in urban areas with chemiresistor gas sensors (CGSs) has been so far widely overlooked, since the average levels are usually low, i.e. in the 20-30 ppb range, while the CGSs are generally tested by exposure to ammonia in the ppm range. Carbon nanotubes (CNTs), discovered more than 20 years ago, are well known and studied systems for many applications, among which (of course) gas sensing. With respect to commercial electrochemical sensors (mostly based on metal oxide materials), CNTs show a higher physical and chemical stability, better transport of charge to the electrodes and a wide range of possible hybrid architectures and operational features, among which the operation at room temperature, that make them unique materials for gas detection. The main goal of this thesis is to increase the sensitivity to [NH3] and to lower the detection limit (DL), exploring sample preparation strategies of low-cost single walled carbon nanotubes (SWCNT)-based gas sensors operating at room temperature, considering also the response to other interfering gases. Furthermore, effects of metal oxide nanoparticles functionalization and gas response of hybrid layers have been also investigated.
Probing the Crust of the Neutron Star in EXO 0748-676
Creators: name: Degenaar, N.
name: Medin, Z.
name: Cumming, A.
name: Wijnands, R.
name: Wolff, M. T.
name: Cackett, E. M.
name: Miller, J. M.
name: Jonker, P. G.
name: Homan, J.
name: Brown, E. F.
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: X-ray observations of quiescent X-ray binaries have the potential to provide insight into the structure and the composition of neutron stars. EXO 0748-676 had been actively accreting for over 24 yr before its outburst ceased in late 2008. Subsequent X-ray monitoring revealed a gradual decay of the quiescent thermal emission that can be attributed to cooling of the accretion-heated neutron star crust. In this work, we report on new Chandra and Swift observations that extend the quiescent monitoring to ~5 yr post-outburst. We find that the neutron star temperature remained at ~117 eV between 2009 and 2011, but had decreased to ~110 eV in 2013. This suggests that the crust has not fully cooled yet, which is supported by the lower temperature of ~95 eV that was measured ~4 yr prior to the accretion phase in 1980. Comparing the data to thermal evolution simulations reveals that the apparent lack of cooling between 2009 and 2011 could possibly be a signature of convection driven by phase separation of light and heavy nuclei in the outer layers of the neutron star.
description: 9 pages, 4 tables, 3 figures. Minor revisions according to referee report. Accepted to ApJ
Esplorare e abitare il Pianeta rosso
Creators: Patrizia Caraveo
Publisher: name: Media Inaf
Year: 2023

Domenica scorsa sul Sole24Ore la recensione di “Le sfide di Marte” e “Le città dell’universo”, firmato il primo dall’esperto di esplorazione spaziale Paolo Ferri dell’Esa e il secondo dagli architetti Annalisa Dominoni e Benedetto Quaquaro. Con il consenso dell’autrice, l’astrofisica Patrizia Caraveo, ve la riproponiamo oggi su Media Inaf
Trigonal warping in bilayer graphene: Energy versus entanglement spectrum
Creators: name: Predin, Sonja
name: Wenk, Paul
name: Schliemann, John
Publisher: name: Universität Regensburg
Year: 2016
Subjects: subject: ENTROPY;
subject: 530 Physik

description: We present a mainly analytical study of the entanglement spectrum of Bernal-stacked graphene bilayers in the presence of trigonal warping in the energy spectrum. Upon tracing out one layer, the entanglement spectrum shows qualitative geometric differences to the energy spectrum of a graphene monolayer. However, topological quantities such as Berry-phase-type contributions to Chern numbers agree. The latter analysis involves not only the eigenvalues of the entanglement Hamiltonian but also its eigenvectors. We also discuss the entanglement spectra resulting from tracing out other sublattices. As a technical basis of our analysis, we provide closed analytical expressions for the full eigensystem of bilayer graphene in the entire Brillouin zone with a trigonally warped spectrum.
The 4.5 $μ$m full-orbit phase curve of the hot Jupiter HD 209458b
Creators: name: Zellem, Robert T.
name: Lewis, Nikole K.
name: Knutson, Heather A.
name: Griffith, Caitlin A.
name: Showman, Adam P.
name: Fortney, Jonathan J.
name: Cowan, Nicolas B.
name: Agol, Eric
name: Burrows, Adam
name: Charbonneau, David
name: Deming, Drake
name: Laughlin, Gregory
name: Langton, Jonathan
Publisher: name: arXiv
Year: 2014
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: The hot Jupiter HD 209458b is particularly amenable to detailed study as it is among the brightest transiting exoplanet systems currently known (V-mag = 7.65; K-mag = 6.308) and has a large planet-to-star contrast ratio. HD 209458b is predicted to be in synchronous rotation about its host star with a hot spot that is shifted eastward of the substellar point by superrotating equatorial winds. Here we present the first full-orbit observations of HD 209458b, in which its 4.5 $μ$m emission was recorded with $Spitzer$/IRAC. Our study revises the previous 4.5 $μ$m measurement of HD 209458b's secondary eclipse emission downward by $\sim$35% to $0.1391%^{+0.0072%}_{-0.0069%}$, changing our interpretation of the properties of its dayside atmosphere. We find that the hot spot on the planet's dayside is shifted eastward of the substellar point by $40.9^{\circ}\pm{6.0^{\circ}}$, in agreement with circulation models predicting equatorial superrotation. HD 209458b's dayside (T$_{bright}$ = 1499 $\pm$ 15 K) and nightside (T$_{bright}$ = 972 $\pm$ 44 K) emission indicates a day-to-night brightness temperature contrast smaller than that observed for more highly irradiated exoplanets, suggesting that the day-to-night temperature contrast may be partially a function of the incident stellar radiation. The observed phase curve shape deviates modestly from global circulation model predictions potentially due to disequilibrium chemistry or deficiencies in the current hot CH$_{4}$ line lists used in these models. Observations of the phase curve at additional wavelengths are needed in order to determine the possible presence and spatial extent of a dayside temperature inversion, as well as to improve our overall understanding of this planet's atmospheric circulation.
description: 10 pages, 6 figures, 3 tables, published in ApJ
Cheilosia longula Zetterstedt 1838
Creators: name: MAZáNEK, Libor
name: VONIČKA, Pavel
name: PREISLER, JiřÍ
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Syrphidae
Cheilosia
Cheilosia longula

description: Cheilosia longula Zetterstedt, 1838 Eurosibiřský druh. Vyskytuje se řÍdce v listnatých a zejména jehličnatých lesÍch včetně kulturnÍch, kde vyhledÁvÁ nejrůznějšÍ drobné světliny s nižšÍ vegetacÍ. Larvy žijÍ v plodnicÍch hřibovitých hub, zejména rodů Boletus, Leccinum, Suillus aj. Rašeliniště Jizerky NPR [33a]: 17.VIII.-1.IX.2005, 1 ♀ (YPT). Rybí loučky PR [37]: 23.VII.-5.VIII.2003, 1 ♂ (YPT).
description: Published as part of MAZáNEK, Libor, VONIČKA, Pavel & PREISLER, JiřÍ, 2009, Syrphidae (Diptera) of the Jizerské hory Mts and Frýdlant region (northern Bohemia, Czech Republic), pp. 3-46 in Sborník Severočeského Muzea 27 on pages 35-36, DOI: 10.5281/zenodo.7153554
Saturno, una vista fuori dal comune
Creators: Jacopo Danieli
Publisher: name: Media Inaf
Year: 2023

Il 25 giugno il grande specchio del telescopio spaziale James Webb è stato puntato verso uno dei pianeti più affascinanti del Sistema solare: Saturno. L’osservazione all’infrarosso ha rivelato un’insolita immagine del pianeta, estremamente scuro e privo delle caratteristiche bande, e nuovi interessanti dettagli degli anelli e della sua atmosfera, oltre che tre delle sue numerose lune: Dione, Encelado e Teti
La lentezza dell’universo nel ticchettio dei quasar
Creators: Maura Sandri
Publisher: name: Media Inaf
Year: 2023

Combinando le osservazioni di 190 quasar osservati nell'arco di due decenni, effettuate a diverse lunghezze d'onda, due scienziati hanno trovato che l'espansione dell'universo è impressa nei quasar – che possono essere usati come riferimenti standard, così come le supernove a distanze inferiori. In accordo con la relatività di Einstein, l'universo sembra quindi accelerare man mano che invecchia
Helioseismology with long range dark matter-baryon interactions
Creators: name: Lopes, Ilídio
name: Panci, Paolo
name: Silk, Joseph
Publisher: name: arXiv
Year: 2014
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Assuming the existence of a primordial asymmetry in the dark sector, we study how DM-baryon long-range interactions, induced by the kinetic mixing of a new $U(1)$ gauge boson and the photon, affects the evolution of the Sun and in turn the sound speed profile obtained from helioseismology. Thanks to the explicit dependence on the exchanged momenta in the differential cross section (Rutherford-like scattering), we find that dark matter particles with a mass of $\sim 10\;{\rm GeV}$, kinetic mixing parameter of the order of $10^{-9}$ and a mediator with a mass smaller than a few MeV improve the agreement between the best solar model and the helioseismic data without being excluded by direct detection experiments. In particular, the \LUX\ detector will soon be able to either constrain or confirm our best fit solar model in the presence of a dark sector with long-range interactions that reconcile helioseismology with thermal neutrino results.
description: v2: new section on the importance of the self-interaction added, discussion on its magnitude added, some clarifications and some references added, few typos corrected, results slightly modified; matches version published on ApJ ; article with 12 pages and 4 figures
Cheilosia melanopa
Creators: name: MAZáNEK, Libor
name: VONIČKA, Pavel
name: PREISLER, JiřÍ
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Syrphidae
Cheilosia
Cheilosia melanopa

description: Cheilosia melanopa (Zetterstedt, 1843) Evropský druh s boreomontÁnnÍm rozšÍřenÍm. Vyskytuje se vzÁcně v okolÍ vodotečÍ podhorských a horských oblastÍ, kde usedÁ na osluněné skÁly a vegetaci. Rašeliniště Jizerky NPR [33a]: 19.V.-3.VI.2005, 1 ♂ (YPT). Rejdice [35]: 3.-19.V.2005, 3 ♂♂ (YPT).
description: Published as part of MAZáNEK, Libor, VONIČKA, Pavel & PREISLER, JiřÍ, 2009, Syrphidae (Diptera) of the Jizerské hory Mts and Frýdlant region (northern Bohemia, Czech Republic), pp. 3-46 in Sborník Severočeského Muzea 27 on page 36, DOI: 10.5281/zenodo.7153554
Amplitude dependence of image quality in atomically-resolved bimodal atomic force microscopy
Creators: name: Ooe, Hiroaki
name: Kirpal, Dominik
name: Wastl, Daniel S.
name: Weymouth, Alfred J.
name: Toyoko, Arai
name: Giessibl, Franz J.
Publisher: name: Universität Regensburg
Year: 2016
Subjects: subject: QUARTZ TUNING FORK; HYDRATION FORCES; RESOLUTION; SURFACES; WATER; AIR; CANTILEVERS; SENSOR; MODE;
subject: 530 Physik

description: In bimodal frequency modulation atomic force microscopy (FM-AFM), two flexural modes are excited simultaneously. We show atomically resolved images of KBr(100) in ambient conditions in both modes that display a strong correlation between the image quality and amplitude. We define the sum amplitude as the sum of the amplitudes of both modes. When the sum amplitude becomes larger than about 100 pm, the signal-to-noise ratio (SNR) drastically decreases. We propose that this is caused by the temporary presence of one or more water layers in the tip-sample gap. These water layers screen the short range interaction and must be displaced with each oscillation cycle. Decreasing the amplitude of either mode, however, increases the noise. Therefore, the highest SNR in ambient conditions is achieved when twice the sum amplitude is slightly less than the thickness of the primary hydration layer. Published by AIP Publishing.
I didn’t see that coming: Waste and psychological distance in online grocery shopping
Creators: name: Panas, George
Publisher: name: Monash University
Year: 2022
Subjects: Supply chains
Consumer behaviour
Waste management, reduction, reuse and recycling

description: This study draws on construal level theory to explore the concepts of supply chain transparency, waste and psychological distance in online grocery shopping. The study proposes that consumers in a more abstract mindset place less weight on peripheral details, such as how a product will be packaged for delivery, than those in a more concrete mindset. It further proposes that consumers can be stimulated into placing greater weight on perceptions of wastefulness in product choices, with an intervention of globally framed waste messaging, raising awareness regarding the impact of potential food and packaging waste.
Attempts to test an alternative electrodynamic theory of superconductors by low-temperature scanning tunneling and atomic force microscopy
Creators: name: Peronio, Angelo
name: Giessibl, Franz J.
Publisher: name: Universität Regensburg
Year: 2016
Subjects: subject: SURFACE; TIPS; NANOSCALE; CHARGE; STM;
subject: 530 Physik

description: We perform an experiment to test between two theories of the electrodynamics of superconductors: the standard London theory and an alternative proposed by J. E. Hirsch [Phys. Rev. B 69, 214515 (2004)]. The two alternatives give different predictions with respect to the screening of an electric field by a superconductor, and we try to detect this effect using atomic force microscopy on a niobium sample. We also perform the reverse experiment, where we demonstrate a superconductive tip mounted on a qPlus force sensor. Due to limited accuracy, we are able neither to prove nor to disprove Hirsch's hypothesis. Within our accuracy of 0.17 N/m, the superconductive transition does not alter the atomic-scale interaction between tip and sample.
Terahertz-Driven Nonlinear Spin Response of Antiferromagnetic Nickel Oxide
Creators: name: Baierl, Sebastian
name: Mentink, J. H.
name: Hohenleutner, Matthias
name: Braun, L.
name: Do, T.-M.
name: Lange, Christoph
name: Sell, A.
name: Fiebig, M.
name: Woltersdorf, Georg
name: Kampfrath, T.
name: Huber, Rupert
Publisher: name: Universität Regensburg
Year: 2016
Subjects: subject: MAGNETIZATION; ULTRAFAST; RESONANCE; DYNAMICS; LIGHT; GENERATION; WAVES; ORDER; FIELD;
subject: 530 Physik

description: Terahertz magnetic fields with amplitudes of up to 0.4 Tesla drive magnon resonances in nickel oxide while the induced dynamics is recorded by femtosecond magneto-optical probing. We observe distinct spin-mediated optical nonlinearities, including oscillations at the second harmonic of the 1 THz magnon mode. The latter originate from coherent dynamics of the longitudinal component of the antiferromagnetic order parameter, which are probed by magneto-optical effects of second order in the spin deflection. These observations allow us to dynamically disentangle electronic from lattice-related contributions to magnetic linear birefringence and dichroism-information so far only accessible by ultrafast THz spin control. The nonlinearities discussed here foreshadow physics that will become essential in future subcycle spin switching.
Mostri in crescita sotto l’occhio di Webb
Creators: Laura Leonardi
Publisher: name: Media Inaf
Year: 2023

Nuove osservazioni di Webb mostrano un insieme di galassie tenute insieme gravitazionalmente tra loro da un vasto filamento collegato a un quasar molto distante e luminoso. I ricercatori sostengono che questa struttura evolverà in un enorme ammasso di galassie. I risultati della ricerca sono stati pubblicati in due articoli su The Astrophysical Journal Letters
C’è molta più luce nell’universo primordiale
Creators: Giuseppe Fiasconaro
Publisher: name: Media Inaf
Year: 2023

Analizzando le immagini dello spazio profondo catturate dallo strumento NirCam di Jwst, un team di ricercatori guidati dal Center for Astrobiology ha trovato nell'universo primordiale, ossia a pochi milioni di anni dopo il Big Bang, molte più galassie di quelle previste dalle simulazioni cosmologiche. Galassie che, oltretutto, sembrano essere molto più luminose e compatte di quanto si pensasse
L’ultima Venere e l’arco della Via Lattea
Creators: Fabrizio Villa
Publisher: name: Media Inaf
Year: 2023

In luglio non perdete l'ultima occasione per osservare Venere, prima che sparisca immersa nella luce del Sole. Per chi ha la fortuna di potersi godere cieli bui, questo è il mese più adatto per osservare la Via Lattea. In corrispondenza della costellazione del Sagittario, la Galassia si mostra in tutta la sua bellezza: con un binocolo non sarà difficile rendersi conto della miriade di ammassi e nebulose presenti
Cheilosia nigripes
Creators: name: MAZáNEK, Libor
name: VONIČKA, Pavel
name: PREISLER, JiřÍ
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Syrphidae
Cheilosia
Cheilosia nigripes

description: Cheilosia nigripes (Meigen, 1822) Palearktický druh, široce rozšÍřený zejména v nižšÍch polohÁch, kde vyhledÁvÁ travnaté světliny v listnatých lesÍch. Křížový vrch PR [18]: 30.IV.2003, 1 ♂ (SW).
description: Published as part of MAZáNEK, Libor, VONIČKA, Pavel & PREISLER, JiřÍ, 2009, Syrphidae (Diptera) of the Jizerské hory Mts and Frýdlant region (northern Bohemia, Czech Republic), pp. 3-46 in Sborník Severočeského Muzea 27 on page 36, DOI: 10.5281/zenodo.7153554
Partita la missione europea Euclid
Creators: Ufficio stampa Inaf
Publisher: name: Media Inaf
Year: 2023

Lanciato con successo il satellite che misurerà gli spettri di milioni di galassie e studierà la materia e l’energia oscura. «L’Italia è tra i maggiori partecipanti», ricorda Marco Tavani, presidente Inaf. «Al nostro Paese fa capo infatti circa un quarto di tutto l’impegno necessario per realizzare e far funzionare il satellite, nonché per sfruttare i risultati scientifici della missione»
On the Bishop-Phelps-Bollobás property for numerical radius
Creators: name: Kim, Sun Kwang
name: Lee, Han Ju
name: Martín, Miguel
Publisher: name: arXiv
Year: 2013
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: Primary 46B20, Secondary 46B04, 46B22

description: We study the Bishop-Phelps-Bollobás property for numerical radius (in short, BPBp-nu) and find sufficient conditions for Banach spaces ensuring the BPBp-nu. Among other results, we show that $L_1(μ)$-spaces have this property for every measure $μ$. On the other hand, we show that every infinite-dimensional separable Banach space can be renormed to fail the BPBp-nu. In particular, this shows that the Radon-Nikodým property (even reflexivity) is not enough to get BPBp-nu.
Two-Colour Free Electron Laser with Wide Frequency Separation using a Single Monoenergetic Electron Beam
Creators: name: Campbell, L. T.
name: McNeil, B. W. J.
name: Reiche, S.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Accelerator Physics (physics.acc-ph)
subject: FOS: Physical sciences

description: Studies of a broad bandwidth, two-colour FEL amplifier using one monoenergetic electron beam are presented. The two-colour FEL interaction is achieved using a series of undulator modules alternately tuned to two well-separated resonant frequencies. Using the broad bandwidth FEL simulation code Puffin, the electron beam is shown to bunch strongly and simultaneously at the two resonant frequencies. Electron bunching components are also generated at the sum and difference of the resonant frequencies.
description: Accepted for publication
Una notte al Tng per Raffaele e Chiara
Creators: Gloria Andreuzzi
Publisher: name: Media Inaf
Year: 2023

Si è appena concluso alle Canarie – sull’isola di La Palma, dove sorge il Telescopio nazionale Galileo – lo stage annuale riservato ai due membri della categoria senior della squadra azzurra dei Campionati italiani di astronomia. Ci racconta com’è andata Gloria Andreuzzi, astronoma al Tng e responsabile dell’organizzazione dello stage
Deterministic transfer of spin polarization in wire-like lateral structures via the persistent spin helix
Creators: name: Schwemmer, M.
name: Hanninger, A.
name: Weingartner, M.
name: Oltscher, M.
name: Ciorga, Mariusz
name: Weiss, Dieter
name: Schuh, Dieter
name: Bougeard, Dominique
name: Korn, Tobias
name: Schüller, Christian
Publisher: name: Universität Regensburg
Year: 2016
Subjects: subject: ELECTRON-GAS;
subject: 530 Physik

description: We used spatially- and time-resolved Kerr rotation microscopy to show that in lateral wire-like structures, based on a modulation-doped GaAs-AlGaAs quantum well, an optically initialized spin polarization can be deterministically transferred to specific lateral positions, employing the persistent spin helix (PSH). To this end, we show that confinement in two directions leads to a strong enhancement of the effective decay time of spin polarization, which can be exploited to transfer spin polarization over relatively large lateral distances. This is demonstrated by the investigation of L-shaped wire-like lateral structures, where the legs are positioned in directions parallel and perpendicular to the wave vector of the PSH. Published by AIP Publishing.
Come nell’universo locale, così in quello lontano
Creators: Claudia Mignone
Publisher: name: Media Inaf
Year: 2023

Nuove immagini di Jwst hanno rivelato, per la prima volta, la luce stellare di due galassie massicce che ospitano buchi neri attivi a meno di un miliardo di anni dal Big Bang. L'analisi delle osservazioni ha mostrato che i due buchi neri sono circa cento volte meno massicci rispetto alle loro galassie ospiti, un rapporto simile a quello che si trova nell'universo più recente. Tutti i dettagli su Nature