cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Orientation-averaged light scattering by nanoparticle clusters: far-field and near-field benchmarks of numerical cubature methods
Creators: name: Fazel-Najafabadi, Atefeh
name: Auguié, Baptiste
Publisher: name: arXiv
Year: 2022
Subjects: subject: Optics (physics.optics)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: The optical properties of nanoparticles can be substantially affected by their assembly in compact aggregates. This is a common situation notably for nanoparticles synthesised and self-assembled into rigid clusters in colloidal form, where they may be further characterised or used in spectroscopic applications. The theoretical description of such experiments generally requires averaging the optical response over all possible cluster orientations, as they randomly orient themselves over the course of a measurement. This averaging is often done numerically by simulating the optical response for several directions of incidence, using a spherical cubature method. The simulation time increases with the number of directions and can become prohibitive, yet few studies have examined the trade-off between averaging accuracy and computational cost. We benchmark seven commonly-used spherical cubature methods for both far-field and near-field optical responses for a few paradigmatic cluster geometries: dimers of nanospheres and of nanorods, and a helix. The relative error is rigorously evaluated in comparison to analytical results obtained with the superposition T-matrix method. Accurate orientation averaging is especially important for quantities relating to optical activity, the differential response to left and right circularly polarised light, and our example calculations include in particular far-field circular dichroism and near-field local degree of optical chirality.
description: 12 pages, 7 figures; ESI available
Photoluminescence of double quantum wells: asymmetry and excitation laser wavelength effects
Creators: name: Bravo-Velazquez, C. A.
name: Lastras-Martinez, L. F
name: Ruiz-Cigarrillo, O.
name: Flores-Rangel, G.
name: Tapia-Rodriguez, L. E
name: Biermann, K.
name: Santos, P. V.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Circularly polarized photoluminescence (PL) spectroscopy measured at 19 K on GaAs/AlGaAs symmetric and asymmetric double quantum wells (DQW) is reported. The PL is obtained by exciting the sample with a circularly polarized (left or right) laser in order to create an initial unbalanced distribution of electron spins in the conduction band and, in this way, obtain the electron spin lifetime $τ_s$. The effects of the excitation laser wavelength were estimated by exciting with laser wavelengths of 701.0 nm, 787.0 nm, 801.5 nm and 806.5 nm. The increase of $τ_s$ with the excitation wavelength is attributed to the lower initial quasi-momentum $\bf{k}$ of the excited carriers, which also reduces spin-orbit relaxation processes. $τ_s$ was found to be higher in asymmetric DQWs: this is attributed to the wider QWs in these samples, which reduces spin relaxation due to the Dresselhaus mechanism. In addition, we also detected a smaller contribution from the Rashba mechanism by comparing samples with built-in electric fields of different orientations defined by doped barrier layers.
description: 12 pages, 5 figures
Moiré-Bose-Hubbard model for interlayer excitons in twisted transition metal dichalcogenide heterostructures
Creators: name: Götting, N.
name: Lohof, F.
name: Gies, C.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: In bilayers of semiconducting transition metal dichalcogenides, the twist angle between layers can be used to introduce a highly regular periodic potential modulation on a length scale that is large compared to the unit cell. In such structures, correlated states can emerge, in which excitons in the heterostructure are strongly localized to the potential minima due to exciton-exciton interactions. We explore the transition between Mott and extended exciton phases in terms of a moiré-Bose-Hubbard Hamiltonian. Hopping and on-site interaction parameters are obtained from a Wannier representation of the interlayer-exciton wave functions, and a non-local Rytova-Keldysh model is used to attribute for the dielectric screening of excitons in the two-dimensional material. For sufficiently small exciton concentrations and substrate screening our model predicts the emergence of Mott-insulating states, establishing twisted TMD heterostructures as possible quantum simulators for bosonic many-body systems.
description: v2 for resubmission to jurnal
A Bayesian Based Deep Unrolling Algorithm for Single-Photon Lidar Systems
Creators: name: Koo, Jakeoung
name: Halimi, Abderrahim
name: McLaughlin, Stephen
Publisher: name: arXiv
Year: 2022
Subjects: subject: Image and Video Processing (eess.IV)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Deploying 3D single-photon Lidar imaging in real world applications faces multiple challenges including imaging in high noise environments. Several algorithms have been proposed to address these issues based on statistical or learning-based frameworks. Statistical methods provide rich information about the inferred parameters but are limited by the assumed model correlation structures, while deep learning methods show state-of-the-art performance but limited inference guarantees, preventing their extended use in critical applications. This paper unrolls a statistical Bayesian algorithm into a new deep learning architecture for robust image reconstruction from single-photon Lidar data, i.e., the algorithm's iterative steps are converted into neural network layers. The resulting algorithm benefits from the advantages of both statistical and learning based frameworks, providing best estimates with improved network interpretability. Compared to existing learning-based solutions, the proposed architecture requires a reduced number of trainable parameters, is more robust to noise and mismodelling effects, and provides richer information about the estimates including uncertainty measures. Results on synthetic and real data show competitive results regarding the quality of the inference and computational complexity when compared to state-of-the-art algorithms.
Discovery of late-time X-ray flare and anomalous emission line enhancement after the nuclear optical outburst in a narrow-line Seyfert 1 Galaxy
Creators: name: Zhang, W. J.
name: Shu, X. W.
name: Sheng, Z. F.
name: Sun, L. M.
name: Dou, L. M.
name: Jiang, N.
name: Wang, J. G.
name: Hu, X. Y.
name: Wang, Y. B.
name: Wang, T. G.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: CSS J102913+404220 is a peculiar narrow line Seyfert 1 galaxy with an energetic nuclear optical outburst. We present a detailed analysis of its multi-wavelength photometric and spectroscopic observations covering a period of decade since outburst. We detect mid-infrared (MIR) flares delayed by about two months relative to the optical outburst, with an extremely high peak luminosity of log(L_4.6um)>44 erg/s. The MIR peak luminosity is at least an order of magnitude higher than any known supernovae explosions, suggesting the optical outburst might be due to a stellar tidal disruption event (TDE). We find late-time X-ray brightening by a factor of >30 with respect to what is observed about 100 days after the optical outburst peak, followed by a flux fading by a factor of ~4 within two weeks, making it one of Active Galactic Nuclei (AGNs) with extreme variability. Despite the dramatic X-ray variability, there are no coincident strong flux variations in optical, UV and MIR bands. This unusual variability behavior has been seen in other highly accreting AGNs and could be attributed to absorption variability. In this scenario, the decrease in the covering factor of absorber with accretion rate could cause the X-ray brightening, possibly induced by the TDE. Most strikingly, while the UV/optical continuum remains little changes with time, an evident enhancement in the flux of H_alpha broad emission line is observed, about a decade after the nuclear optical outburst, which is an anomalous behavior never seen in any other AGNs. Such an H_alpha anomaly could be explained by the replenishment of gas clouds and excitation within Broad Line Region (BLR) that originates, perhaps from the interaction of outflowing stellar debris with BLR. The results highlight the importance of late-time evolution of TDE that could affect the accreting properties of AGN, as suggested by recent simulations.
description: Accepted for publication in A&A, 16 pages, 16 figures and 4 Tables
A partial filament eruption in three steps induced by external magnetic reconnection
Creators: name: Dai, Jun
name: Li, Zhentong
name: Wang, Ya
name: Xu, Zhe
name: Zhang, Yanjie
name: Li, Leping
name: Zhang, Qingmin
name: Su, Yingna
name: Ji, Haisheng
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present an investigation of partial filament eruption on 2012 June 17 in the active region NOAA 11504. For the first time, we observed the vertical splitting process during the partial eruption with high resolution narrow band images at 10830 . The active filament was rooted in a small sunspot of the active region. Particularly, it underwent the partial eruption in three steps, i.e. the precursor, the first eruption, and the second eruption, while the later two were associated with a C1.0 flare and a C3.9 flare, respectively. During the precursor, slow magnetic reconnection took place between the filament and the adjoining loops that also rooted in the sunspot. The continuous reconnection not only caused the filament to split into three groups of threads vertically but also formed a new filament, which was growing and accompanied brightening took place around the site. Subsequently, the growing filament erupted together with one group splitted threads, resulted in the first eruption. At the beginning of the first eruption, a subsequent magnetic reconnection occurred between the erupting splitted threads and another ambient magnetic loop. After about three minutes, the second eruption occurred as a result of the eruption of two larger unstable filaments induced by the magnetic reconnection. The high-resolution observation provides a direct evidence that magnetic reconnection between filament and its ambient magnetic fields could induce the vertical splitting of the filament, resulting in partial eruption.
description: 15 pages,10 figures
Mean-field equations for neural populations with $q$-Gaussian heterogeneities
Creators: name: Pyragas, Viktoras
name: Pyragas, Kestutis
Publisher: name: arXiv
Year: 2022
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: Describing the collective dynamics of large neural populations using low-dimensional models for averaged variables has long been an attractive task in theoretical neuroscience. Recently developed reduction methods make it possible to derive such models directly from the microscopic dynamics of individual neurons. To simplify the reduction, the Cauchy distribution is usually assumed for heterogeneous network parameters. Here we extend the reduction method for a wider class of heterogeneities defined by the $q$-Gaussian distribution. The shape of this distribution depends on the Tsallis index $q$ and gradually changes from the Cauchy distribution to the normal Gaussian distribution as this index changes. We derive the mean-field equations for an inhibitory network of quadratic integrate-and-fire neurons with a $q$-Gaussian distributed excitability parameter. It is shown that the dynamic modes of the network significantly depend on the form of the distribution determined by the Tsallis index. The results obtained from the mean-field equations are confirmed by numerical simulation of the microscopic model.
The academic outcomes of first-in-family in an Australian university: An exploratory study
Creators: name: Southgate, E.
name: Douglas, H.
name: Scevak, J.
name: MacQueen, S.
name: Rubin, Mark
name: Lindell, C.
Publisher: name: figshare
Year: 2014
Subjects: subject: Sociology
subject: FOS: Sociology

description: Although the first-generation and first-in-family status (FIF) of university students has been of intense interest in the USA, it has received very little consideration in Australia. The present research redressed this imbalance by investigating the academic outcomes of FIF undergraduate students at a large, public, Australian university. Undergraduate students (N = 227) who were enrolled in education, nursing and liberal arts degrees completed an online survey. Data are representative of typical gender enrolment patterns for these degrees. In contrast to US research, there was no clear relationship between socioeconomic status and FIF status in this sample. Consistent with US research, FIF students had poorer academic outcomes than non-FIF students. However, this difference was only significant after the first-year of study when students were less likely to receive scaffolded learning support within courses. FIF students were more likely than non-FIF students to seek support from university services. The implications of these results for Australian universities are considered.
Water content trends in K2-138 and other low-mass multiplanetary systems
Creators: name: Acuña, Lorena
name: Lopez, Theo
name: Morel, Thierry
name: Deleuil, Magali
name: Mousis, Olivier
name: Aguichine, Artyom
name: Marcq, Emmanuel
name: Santerne, Alexandre
Publisher: name: arXiv
Year: 2022
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Super-Earths and sub-Neptunes have been found simultaneously in multiplanetary systems, suggesting that they are appropriate to study composition and formation within the same environment. We perform a homogeneous interior structure analysis of five multiplanetary systems to explore the compositional trends and its relation with planet formation. For K2-138, we present revised masses and stellar host chemical abundances to improve the constraints on the planetary interior. We conduct a line-by-line differential spectroscopic analysis on the stellar spectra to obtain its chemical abundances and the planetary parameters. We select multiplanetary systems with five or more low-mass planets that have both mass and radius data available. We carry out a homogeneous interior structure analysis on the systems K2-138, TOI-178, Kepler-11, Kepler-102 and Kepler-80 and estimate the volatile mass fraction of their planets assuming a volatile layer constituted of water in steam and supercritical phases. Our interior-atmosphere model takes into account the effects of irradiation on the surface conditions. K2-138 inner planets present an increasing volatile mass fraction with distance from its host star, while the outer planets present an approximately constant water content. This is similar to the trend observed in TRAPPIST-1 in a previous analysis with the same interior-atmosphere model. The Kepler-102 system could potentially present this trend. In all multiplanetary systems, the low volatile mass fraction of the inner planets could be due to atmospheric escape while the higher volatile mass fraction of the outer planets can be the result of accretion of ice-rich material in the vicinity of the ice line with later inward migration. Kepler-102 and Kepler-80 present inner planets with high core mass fractions which could be due to mantle evaporation, impacts or formation in the vicinity of rocklines.
description: 15 pages, 4 figures. Accepted for publication in A&A
Synthesis, structural studies, electrical conductivity and optical properties of new Sb2−xLnxTe3 (Ln: Lu3+, Er3+ and Ho3+) nanomaterials
Creators: name: Y. Hanifehpour
name: A. Alemi
name: S.W. Joo
name: B. Min
Publisher: name: Taylor & Francis
Year: 2014
Subjects: subject: Developmental Biology
subject: Biological Sciences
subject: Chemistry
subject: Earth and Environmental Sciences
subject: Physiology
subject: FOS: Biological sciences
subject: Cell Biology
subject: Physics
subject: Engineering
subject: Biophysics

description: Ln-doped Sb2Te3 (Ln: Lu3+, Er3+, Ho3+) nanomaterials were synthesised by a co-reduction method in hydrothermal condition. Powder X-ray diffraction (XRD) patterns indicate that the LnxSb2−xTe3 crystals (Ln = Lu3+, x = 0.00–0.06; Er3+ and Ho3+x = 0.00–0.04) are isostructural with Sb2Te3. The cell parameter a decreases for LnxSb2−xTe3 compounds upon increasing the dopant content (x), while c increases. Scanning electron microscopy and transmission electron microscopy images show that doping of Lu3+ and Ho3+ ions in the lattice of Sb2Te3 results in spherical nanoparticles while that in Er3+ leads to hexagonal nanoplates, respectively. The electrical conductivity of Ln-doped Sb2Te3 is higher than that of pure Sb2Te3 and increases with temperature. By increasing the concentration of Ln3+ ions, the absorption spectrum of Sb2Te3 shows red shifts and some intensity changes. In addition to the characteristic red emission peaks of Sb2Te3, emission spectra of doped materials show other emission bands originating from f–f transitions of the Ho3+ ions.
The Low-Redshift Lyman Continuum Survey I: New, Diverse Local Lyman-Continuum Emitters
Creators: name: Flury, Sophia R.
name: Jaskot, Anne E.
name: Ferguson, Harry C.
name: Worseck, Gabor
name: Makan, Kirill
name: Chisholm, John
name: Saldana-Lopez, Alberto
name: Schaerer, Daniel
name: McCandless, Stephan
name: Wang, Bingjie
name: Ford, N. M.
name: Heckman, Timothy
name: Ji, Zhiyuan
name: Giavalisco, Mauro
name: Amorin, Ricardo
name: Atek, Hakim
name: Blaizot, Jeremy
name: Borthakur, Sanchayeeta
name: Carr, Cody
name: Castellano, Marco
name: Cristiani, Stefano
name: de Barros, Stephane
name: Dickinson, Mark
name: Finkelstein, Steven L.
name: Fleming, Brian
name: Fontanot, Fabio
name: Garel, Thibault
name: Grazian, Andrea
name: Hayes, Matthew
name: Henry, Alaina
name: Mauerhofer, Valentin
name: Micheva, Genoveva
name: Oey, M. S.
name: Ostlin, Goran
name: Papovich, Casey
name: Pentericci, Laura
name: Ravindranath, Swara
name: Rosdahl, Joakim
name: Rutkowski, Michael
name: Santini, Paola
name: Scarlata, Claudia
name: Teplitz, Harry
name: Thuan, Trinh
name: Trebitsch, Maxime
name: Vanzella, Eros
name: Verhamme, Anne
name: Xu, Xinfeng
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The origins of Lyman continuum (LyC) photons responsible for the reionization of the universe are as of yet unknown and highly contested. Detecting LyC photons from the epoch of reionization is not possible due to absorption by the intergalactic medium, which has prompted the development of several indirect diagnostics to infer the rate at which galaxies contribute LyC photons to reionize the universe by studying lower-redshift analogs. We present the Low-redshift Lyman Continuum Survey (LzLCS) comprising measurements made with HST/COS for a z=0.2-0.4 sample of 66 galaxies. After careful processing of the FUV spectra, we obtain a total of 35 Lyman continuum emitters (LCEs) detected with 97.725% confidence, nearly tripling the number of known local LCEs. We estimate escape fractions from the detected LyC flux and upper limits on the undetected LyC flux, finding a range of LyC escape fractions up to 50%. Of the 35 LzLCS LCEs, 12 have LyC escape fractions greater than 5%, more than doubling the number of known local LCEs with cosmologically relevant LyC escape.
description: ApJS, accepted. 28 pages, 19 figures, 8 tables. Full machine readable tables will be made available by the publisher at the time of publication
Variability of the Incompressible Energy Cascade Rate in Solar Wind Turbulence Around Mars
Creators: name: Romanelli, Norberto
name: Andres, Nahuel
name: DiBraccio, Gina
Publisher: name: arXiv
Year: 2022
Subjects: subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: We present a statistical analysis on the variability of the incompressible energy cascade rate in the solar wind around Mars, making use of an exact relation for fully developed turbulence and more than five years of Mars Atmosphere and Volatile EvolutioN (MAVEN) observations. Using magnetic field and plasma data, we compute the energy cascade rate in the magnetohydrodynamics (MHD) scales in the pristine solar wind. From our statistical results, we conclude that the incompressible energy cascade rate decreases as the Martian heliocentric distance increases, for each of the three explored Martian years. Moreover, we show that the presence of proton cyclotron waves, associated with the extended Martian hydrogen exosphere, do not have a significant effect in the nonlinear cascade of energy at the MHD scales.
description: 13 pages, 4 figures
A$^{3}$COSMOS: A census on the molecular gas mass and extent of main-sequence galaxies across cosmic time
Creators: name: Wang, Tsan-Ming
name: Magnelli, Benjamin
name: Schinnerer, Eva
name: Liu, Daizhong
name: Modak, Ziad Aziz
name: Jiménez-Andrade, Eric Faustino
name: Karoumpis, Christos
name: Kokorev, Vasily
name: Bertoldi, Frank
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: To constrain for the first time the mean mass and extent of the molecular gas of a mass-complete sample of $>10^{10}$M$_{\odot}$ main-sequence (MS) galaxies at $0.40.5$ with a value of 300--500 Myr, but increases by a factor of 3 from $z\sim0.5$ to $z\sim0$. This evolution of the molecular gas depletion time of MS galaxies can be predicted from the evolution of their molecular gas surface density and a seemingly universal MS-only $Σ_{M_{\rm mol}}-Σ_{\rm SFR}$ relation with an inferred slope of 1.13, i.e., the so-called KS relation. The far-infrared size of MS galaxies shows no significant evolution with redshift or stellar mass, with a mean circularized half-light radius of 2.2 kpc. Finally, our mean molecular gas masses are lower than previous estimates, likely caused by the fact that literature studies were biased towards individually-detected MS galaxies with massive gas reservoirs. To first order, the molecular gas content of MS galaxies regulates their star formation across cosmic time, while variation of their star formation efficiency plays a secondary role. Despite a large evolution of their gas content and SFRs, MS galaxies evolved along a seemingly universal MS-only KS relation.
description: 27 pages, 19 figures
Synthesis, crystal structure, and thermal stability of ionic cluster compounds (phenH)4[Re4Q4(CN)12]·nH2O (Q = S, Se, n = 6; Q = Te, n = 10)
Creators: name: Gayfulin, Yakov M.
name: Smolentsev, Anton I.
name: Mironov, Yuri V.
Publisher: name: Taylor & Francis
Year: 2015
Subjects: subject: Cancer
subject: Information and Computing Sciences
subject: Biological Sciences
subject: Ecology
subject: FOS: Biological sciences
subject: Chemistry
subject: Earth and Environmental Sciences
subject: Pharmacology
subject: Cell Biology
subject: Microbiology
subject: Biochemistry
subject: Biophysics

description: Three new salts of tetrahedral rhenium chalcocyanide cluster anions [Re4Q4(CN)12]4− (Q = S, Se, Te) and 1,10-phenanthroline-1-ium cations, (phenH)4[Re4S4(CN)12]·6H2O (1), (phenH)4[Re4Se4(CN)12]·6H2O (2), and (phenH)4[Re4Te4(CN)12]·10H2O (3), have been synthesized by reactions of K4[Re4Q4(CN)12]·nH2O with 1,10-phenanthroline in the presence of Nd3+ in an acidic aqueous medium (pH 4). 1 and 2 exhibit similar 2-D layered supramolecular architectures based on hydrogen bonds between water molecules, CN-groups of cluster anions, and phenH+ cations. The latter are involved in π–π and C–H⋯π stacking interactions, connecting the adjacent layers with each other. Complex 3 demonstrates a 3-D framework based on hydrogen bonds between water molecules and CN-groups, π–π and C–H⋯π interactions. Notably short O···Te contacts of 3.40 and 3.50 Å are found in the structure of 3. The thermal properties of 1–3 have been investigated by TG-DTG.
Quantum Corrections to Soliton Energies
Creators: name: Graham, N.
name: Weigel, H.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We review recent progress in the computation of leading quantum corrections to the energies of classical solitons with topological structure, including multi-soliton models in one space dimension and string configurations in three space dimensions. Taking advantage of analytic continuation techniques to efficiently organize the calculations, we show how quantum corrections affect the stability of solitons in the Shifman-Voloshin model, stabilize charged electroweak strings coupled to a heavy fermion doublet, and bind Nielsen-Olesen vortices at the classical transition between type I and type II superconductors.
description: 40 pages, invited review submitted to a special volume on Casimir Physics (K. Milton, ed.)
Taxonomy, biostratigraphy and palaeoecology of Choerolophodon (Proboscidea, Mammalia) in the Miocene of SE Europe-SW Asia: implications for phylogeny and biogeography
Creators: name: Konidaris, George E.
name: Koufos, George D.
name: Kostopoulos, Dimitris S.
name: Merceron, Gildas
Publisher: name: Taylor & Francis
Year: 2016
Subjects: subject: Evolutionary Biology
subject: FOS: Biological sciences
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: Ecology
subject: 69999 Biological Sciences not elsewhere classified

description: The Miocene elephantoid Choerolophodon from SE Europe-SW Asia is studied, based on the Greek localities of Thymiana, Axios Valley, Pikermi, Samos and Nikiti-2. Although this genus is well documented in Greece, there is no recent taxonomic study and its biostratigraphy and palaeoecology had never been examined in detail. Three choerolophodont species are recognized in SE Europe–SW Asia: the Middle Miocene C. chioticus (late Orleanian, MN 5), and the Late Miocene C. anatolicus (early Vallesian, MN 9) and C. pentelici (late Vallesian–Turolian, MN 10–MN 13). The latter species is divided into a primitive morph, dated to the late Vallesian and possibly earliest Turolian, and an advanced morph from the Turolian. At the end of the Miocene Choerolophodon disappeared. With respect to the geographical distribution of Choerolophodon, the genus is very well documented in SE Europe–SW Asia but it is unknown from Central, Western and Northern Europe, a fact which is attributed to ecological factors. The phylogenetic relationships of all known choerolophodont species from the Miocene of the Old World are examined using a cladistic analysis, and their proposed biogeography is discussed. Finally, the palaeoecology of Late Miocene Choerolophodon from Northern Greece is studied through a dental microwear analysis, revealing that Choerolophodon foraged mainly on grasses, a type of vegetation widespread in open environments. These palaeoecological results are in agreement with previous environmental reconstructions for the Late Miocene of Greece.
How winds and ocean currents influence the drift of floating objects
Creators: name: Wagner, Till J. W.
name: Eisenman, Ian
name: Ceroli, Amanda M.
name: Constantinou, Navid C.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Arctic icebergs, unconstrained sea ice floes, oil slicks, mangrove drifters, lost cargo containers, and other flotsam are known to move at 2-4% of the prevailing wind velocity relative to the water, despite vast differences in the material properties, shapes, and sizes of objects. Here, we revisit the roles of density, aspect ratio, and skin and form drag in determining how an object is driven by winds and water currents. Idealized theoretical considerations show that although substantial differences exist for end members of the parameter space (either very thin or thick and very light or dense objects), most realistic cases of floating objects drift at $\approx$3% of the free-stream wind velocity (measured outside an object's surface boundary layer). This relationship, known as a long-standing rule of thumb for the drift of various types of floating objects, arises from the square root of the ratio of the density of air to that of water. We support our theoretical findings with flume experiments using floating objects with a range of densities and shapes.
description: accepted at the Journal of Physical Oceanography
Taxonomy, biostratigraphy and palaeoecology of Choerolophodon (Proboscidea, Mammalia) in the Miocene of SE Europe-SW Asia: implications for phylogeny and biogeography
Creators: name: Konidaris, George E.
name: Koufos, George D.
name: Kostopoulos, Dimitris S.
name: Merceron, Gildas
Publisher: name: Taylor & Francis
Year: 2014
Subjects: subject: Evolutionary Biology
subject: FOS: Biological sciences
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: Ecology
subject: 69999 Biological Sciences not elsewhere classified

description: The Miocene elephantoid Choerolophodon from SE Europe-SW Asia is studied, based on the Greek localities of Thymiana, Axios Valley, Pikermi, Samos and Nikiti-2. Although this genus is well documented in Greece, there is no recent taxonomic study and its biostratigraphy and palaeoecology had never been examined in detail. Three choerolophodont species are recognized in SE Europe–SW Asia: the Middle Miocene C. chioticus (late Orleanian, MN 5), and the Late Miocene C. anatolicus (early Vallesian, MN 9) and C. pentelici (late Vallesian–Turolian, MN 10–MN 13). The latter species is divided into a primitive morph, dated to the late Vallesian and possibly earliest Turolian, and an advanced morph from the Turolian. At the end of the Miocene Choerolophodon disappeared. With respect to the geographical distribution of Choerolophodon, the genus is very well documented in SE Europe–SW Asia but it is unknown from Central, Western and Northern Europe, a fact which is attributed to ecological factors. The phylogenetic relationships of all known choerolophodont species from the Miocene of the Old World are examined using a cladistic analysis, and their proposed biogeography is discussed. Finally, the palaeoecology of Late Miocene Choerolophodon from Northern Greece is studied through a dental microwear analysis, revealing that Choerolophodon foraged mainly on grasses, a type of vegetation widespread in open environments. These palaeoecological results are in agreement with previous environmental reconstructions for the Late Miocene of Greece.
Stability of Superconducting Nd0.8Sr0.2NiO2 Thin Films
Creators: name: Ding, Xiang
name: Shen, Shengchun
name: Leng, Huaqian
name: Xu, Minghui
name: Zhao, Yan
name: Zhao, Junrui
name: Sui, Xuelei
name: Wu, Xiaoqiang
name: Xiao, Haiyan
name: Zu, Xiaotao
name: Huang, Bing
name: Luo, Huiqian
name: Yu, Pu
name: Qiao, Liang
Publisher: name: arXiv
Year: 2022
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The discovery of superconducting states in the nickelate thin film with infinite-layer structure has paved a new way for studying unconventional superconductivity. So far, research in this field is still very limited due to difficulties in sample preparation. Here we report on the successful preparation of superconducting Nd0.8Sr0.2NiO2 thin film (Tc = 8.0 - 11.1 K) and study the stability of such films in ambient environment, water and under electrochemical conditions. Our work demonstrates that the superconducting state of Nd0.8Sr0.2NiO2 is remarkably stable, which can last for at least 47 days continuous exposure to air at 20 degree Celsius and 35% relative humidity. Further we show the superconductivity disappears after being immersed in de-ionized water at room temperature for 5 hours. Surprisingly, it can also survive under ionic liquid gating conditions with applied voltage up to 4 V, which is even more stable than conventional perovskite complex oxides.
description: 23 pages, 4 figures
K2CO3-Promoted Domino Reactions for Synthesis of Isocoumarins Under Microwave Irradiation
Creators: name: Zhao, Yun-Hui
name: Luo, Ming-Jian
name: Liu, Han-Wen
name: Lin-Hao Wu
Publisher: name: Taylor & Francis
Year: 2015
Subjects: Chemistry
Biotechnology
Physics
Biochemistry
Biological Sciences
Earth and Environmental Sciences

description: A small library of isocoumarin derivatives has been synthesized via K2CO3-catalyzed domino reactions of 2-carboxybenzaldehyde and ω-bromoacetophenones under microwave irradiation (MW). This strategy offers a simple, environmentally acceptable route to synthesize isocoumarin derivatives in moderate to excellent yields. All new compounds were characterized by 1H NMR, 13C NMR, infrared, and high-resolution mass spectroscopic techniques.
Barium stars as tracers of s-process nucleosynthesis in AGB stars I. 28 stars with independently derived AGB mass
Creators: name: Cseh, B.
name: Világos, B.
name: Roriz, M. P.
name: Pereira, C. B.
name: D'Orazi, V.
name: Karakas, A. I.
name: Soós, B.
name: Drake, N. A.
name: Junqueira, S.
name: Lugaro, M.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Barium (Ba) stars are polluted by material enriched in the slow neutron capture (s-process) elements synthesised in the interior of their former asymptotic giant branch (AGB) companion star, which is now a white dwarf. We compare individual Ba star abundance patterns to AGB nucleosynthesis models to verify if the AGB model mass is compatible with independently derived AGB mass. We selected a sample of 28 Ba stars for which both self-consistent spectroscopic observation and analysis are available and stellar mass determinations, via positioning the star on the HR diagram and comparing with evolutionary tracks. For this sample stars we considered both previously and recently derived elemental abundances. Then, we performed a detailed comparison of these s-process elemental abundances to different AGB nucleosynthesis models from the Monash and the FRUITY theoretical data sets. We simplified the binary mass transfer by calculating dilution factors to match the [Ce/Fe] value of each star when using different AGB models, and we then compared the diluted model abundances to the complete Ba-star abundance pattern. Our comparison confirms that low mass, non-rotating AGB stellar models with 13C as the main neutron source are the polluters of the vast majority of the considered Ba stars. Out of the 28 stars, in 21 cases the models are in good agreement with both the determined abundances and the independently derived AGB mass, although in 16 cases higher observed abundances of Nb, Ru, Mo and/or Nd, Sm than predicted. For 3 stars we obtain a match to the abundances only by considering models with masses lower than those independently determined. Finally, 4 stars show much higher first s-process peak abundance values than the model predictions, which may represent the signature of a physical and/or nucleosynthetic process that is not represented in the set of models considered here.
description: accepted for publication in A&A
Analysis of training initiatives undertaken for professional development of library professionals in Pakistan
Creators: name: Ahsan Ullah
Publisher: name: figshare
Year: 2014
Subjects: subject: Library and Information Studies
subject: FOS: Media and communications

description: Abstract: This study has investigated the training initiatives undertaken for professional development of library professionals by different organizations in Pakistan to increase their competence to make them responsive to needs of library users and aggressively fulfill the needs of digital age. Pakistan Library and Automation Group (PakLAG) and Pakistan Library Cooperation Group (LIBCOOP) were used to collect data about the training initiatives uploaded for maximizing participation and sharing reports of initiatives for their knowledge. The messages were searched from these groups from year January, 2009 to 31 December 2013 on yearly basis and all the relevant messages were copied and pasted in a word document. Afterwards these messages were perused online again for checking of duplication and extracting contents of these messages. The content analysis methodology was applied and data was coded and entered in different columns in Microsoft Excel. Simple statistical techniques and sort and filter option in Microsoft Excel was used to analyze data. This study found that most of the training were held at Punjab and Islamabad. Reasonable training were conducted in Sindh and KP but no training has ever been conducted in Baluchistan. The frequency of training initiatives reveals that library automation, role of ICT in libraries, qualitative research, research skills, open source software, web searching skills and use of digital resources are key areas of training initiatives in Pakistan.
Spin chains and vertex models based on superalgebras
Creators: name: Hobuß, Konstantin
Publisher: name: Hannover : Institutionelles Repositorium der Leibniz Universität Hannover
Year: 2019
Subjects: subject: superspin chain
subject: conformal field theory
subject: critical exponents
subject: quasimomentum
subject: Bethe-Ansatz
subject: Superspinkette
subject: Konforme Feldtheorie
subject: Kritische Exponenten
subject: Quasi-Impuls
subject: Dewey Decimal Classification::500 | Naturwissenschaften::530 | Physik

description: The thermodynamic limit of superspin chains can show several intriguing properties, including the emergence of continua of scaling dimensions and the appearance of discrete states when imposing toroidal boundary conditions. Nevertheless, the former’s exhaustive characterization in terms of Conformal Field Theories is still lacking. In order to study the thermodynamic limit of the U_q[sl(2|1)] 3 ⊗ 3̄ superspin chain in the antiferromagnetic regime, we analyze the low lying excitations by means of the model’s exact solution using the Algebraic Bethe Ansatz. In the isotropic limit, this model may be used as a toy model for the description of plateau transitions in Quantum Hall systems. The definition of a quasimomentum operator allows for a characterization of the continua of scaling dimensions, thereby giving rise to a quantum number for the corresponding non-compact component of the spectrum in the thermodynamic limit. The associated degeneracies are lifted on the lattice by logarithmic fine structures. Based on the extrapolation of our finite size data we find that under a variation of the boundary conditions from periodic to antiperiodic for the fermionic degrees of freedom, levels from the continuous part of the spectrum flow into discrete levels and vice versa. Investigating the thermodynamic limit of the q-deformed osp(3|2) superspin chain, corresponding to an intersecting loop model in the rational limit, we seek to uncover its low-lying critical exponents. We present evidences that the latter are built in terms of composites of anomalous dimensions of two Coulomb gases with distinct radii and exponents associated to Z(2) degrees of freedom. This view is supported by the fact that the S = 1 XXZ integrable chain spectrum is present in some of the sectors of the superspin chain at a particular value of the deformation parameter. We find that the fine structure of finite-size effects is very rich for a typical anisotropic spin chain. In fact, we argue on the existence of a family of states with the same conformal dimension whose lattice degeneracies are lifted by logarithmic corrections. On the other hand, we also report on states of the spectrum whose finite-size corrections seem to be governed by a power law behaviour. We finally observe that under toroidal boundary conditions the ground state dependence on the twist angle has two distinct analytical structures.
The binding of atomic hydrogen on graphene from density functional theory and diffusion Monte Carlo calculations
Creators: name: Dumi, Amanda
name: Upadhyay, Shiv
name: Bernasconi, Leonardo
name: Shin, Hyeondeok
name: Benali, Anouar
name: Jordan, Kenneth D.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: In this work density functional theory (DFT) and diffusion Monte Carlo (DMC) methods are used to calculate the binding energy of a H atom chemisorbed on the graphene surface. The Perdew-Burke-Ernzerhof (PBE) value of the binding energy is about 20% larger in magnitude than the diffusion Monte Carlo result. The inclusion of exact exchange through the use of the Heyd-Scuseria-Ernzerhof (HSE) functional brings the DFT value of the binding energy closer in line with the DMC result. It is also found that there are significant differences in the charge distributions determined using PBE and DMC approaches.
description: The following article has been submitted to The Journal of Chemical Physics
Ultralight bosonic dark matter in white dwarfs and potential observational consequences
Creators: name: Sanchis-Gual, Nicolas
name: Izquierdo, Paula
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Fluid and ultralight bosonic dark matter can interact through gravity to form stable fermion-boson stars, which are static and regular mixed solutions of the Einstein-Euler-(complex, massive) Klein-Gordon system. In this work we study the dynamical formation via gravitational cooling of a spherical mixed white-dwarf--boson star, whose properties depend on the boson particle mass and the mass of the boson star. Due to the accretion of bosonic dark matter, the white dwarf migrates to a denser and more compact object with a boson star core, thus modifying its gravitational redshift and altering the electromagnetic radiation emitted from the photosphere. We discuss the implications of the changes in the gravitational redshift that in principle could be produced by any type of dark matter and that might lead to small discrepancies in the estimation of masses and radii derived from white dwarf observations.
description: 13 pages
Synthesis, crystal structure and thermal stability of ionic cluster compounds (phenH)4[Re4Q4(CN)12]·nH2O (Q = S, Se, n = 6; Q = Te, n = 10)
Creators: name: Gayfulin, Yakov M.
name: Smolentsev, Anton I.
name: Mironov, Yuri V.
Publisher: name: Taylor & Francis
Year: 2015
Subjects: subject: Cancer
subject: Information and Computing Sciences
subject: Biological Sciences
subject: Ecology
subject: FOS: Biological sciences
subject: Chemistry
subject: Earth and Environmental Sciences
subject: Pharmacology
subject: Cell Biology
subject: Microbiology
subject: Biochemistry
subject: Biophysics

description: Three new salts of tetrahedral rhenium chalcocyanide cluster anions [Re4Q4(CN)12]4– (Q = S, Se, Te) and 1,10-phenanthroline-1-ium cations, (phenH)4[Re4S4(CN)12]·6H2O (1), (phenH)4[Re4Se4(CN)12]·6H2O (2) and (phenH)4[Re4Te4(CN)12]·10H2O (3), have been synthesized by reactions of K4[Re4Q4(CN)12]·nH2O with 1,10-phenanthroline in the presence of Nd3+ in an acidic aqueous medium (pH ≈ 4). 1 and 2 exhibit similar 2-D layered supramolecular architectures based on hydrogen bonds between water molecules, CN-groups of cluster anions and phenH+ cations. The latter are involved in π-π and C–H∙∙∙π stacking interactions, connecting the adjacent layers with each other. Complex 3 demonstrates a 3-D framework based on hydrogen bonds between water molecules and CN-groups, π-π and C–H∙∙∙π interactions. Notably short O···Te contacts of 3.40 and 3.50 Å are found in the structure of 3. The thermal properties of 1-3 have been investigated by TG-DTG.
Calibration Uncertainty's Impact on Gravitational-Wave Observations
Creators: name: Essick, Reed
Publisher: name: arXiv
Year: 2022
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Our ability to calibrate current kilometer-scale interferometers can potentially confound the inference of astrophysical signals. Current calibration uncertainties are well described by a Gaussian process. I exploit this description to analytically examine the impact of calibration uncertainty. I derive closed-form expressions for the conditioned likelihood of the calibration error given the observed data and an astrophysical signal (astrophysical calibration) as well as for the marginal likelihood for the data given a signal (integrated over the calibration uncertainty). I show that calibration uncertainty always reduces search sensitivity and the amount of information available about astrophysical signals. Additionally, calibration uncertainty will fundamentally limit the precision to which loud signals can be constrained, a crucial factor when considering the scientific potential of proposed third-generation interferometers. For example, I estimate that with $1\%$ uncertainty in the detector response's amplitude and phase, one will only be able to measure the leading-order tidal parameter ($\tildeΛ$) for a 1.4+1.4$\,M_\odot$ system to better than $\pm 1$ ($\sim 0.2\%$ relative uncertainty) for signals with signal-to-noise ratios $\gtrsim 10^4$. At this signal-to-noise ratio, calibration uncertainty increases $σ_{\tildeΛ}$ by a factor of $2$ compared to stationary Gaussian noise alone. Furthermore, 1\% calibration uncertainty limits the precision to always be $σ_{\tildeΛ} \gtrsim 0.5$. I also show how to best select the frequencies at which calibration should be precisely constrained in order to minimize the information lost about astrophysical parameters. It is not necessary to constrain the calibration errors to be small at all frequencies to perform precise astrophysical inference for individual signals.
description: 20 pages, 3 figures, 1 table