bluuebunny/crossref_metadata_2025_split huggingface dataset:
Les phosphates d'uranyle et d'aluminium de Kobokobo. II. La phuralumite Al2 (UO2)3 (PO4)2 (OH)6 • 10H2O et l'upalite Al (UO2)3 (PO4)2 (OH)3, nouveaux minéraux
Authors: Deliens Michel , Piret Paul 
Published: November 2018

Phuralumite occurs as yellow lemon prismatic crystals. Perfect vertical cleavage {010}. Maximum length 1/2 mm. Density (measured) 3.5 g/cm3. Optically biaxial negative, 2V = 40° ; ng (pale yellow) = 1.624, nm (pale yellow) = 1.616 and np (bright yellow) = 1.559. Phuralumite is monoclinic, P21/a with a = 13.87 Å, b = 20.79 Å, c = 9.38 Å and β = 112° ; Z = 4 ; d(calc) = 3.54 g/cm3. The strongest lines of the X-ray powder pattern are : 10.4 Å (100) 020, 3.08 Å (80) 202-213-422, 5.17 Å (70) 040 and 3.40 Å (50) 242. Formula deduced from electron microprobe analysis (H2O by difference) : Al2 (UO2)3(PO4)2(OH)6-10H2O.
Upalite occurs as acicular prisms. Colour : amber yellow, transparent. Maximum length : 1/3 mm. Cleavage {010} distinct. Density (measured) 3.5 g/cm3. The mineral is orthorhombic ; space group Bbcm or Bba2 with a = 34.68 Å , b = 16.81 Å and c = 13.72 Å. Z = 16. Calculated density 3.58 g/cm3. The strongest lines of the X-ray powder pattern are : 8.4 Å (100) 020, 4.18 Å (80) 040, 3.43 Å (80) 004 and 2.903 Å (75) 10.2.2. Upalite is biaxial, 2 V(—) = 74° ; ng (canary yellow) = 1.676, nm (canary yellow) = 1.666 and np (colourless) = 1.649. Formula from microprobe analysis (H2O by difference) : Al (UO2)3 (OP4)2 (OH)3. Structural group of phosphuranylite, as well as phuralumite.
Both minerals occur at Kobokobo, Kivu, Zaïre, as crystalline crusts and veinlets on pegmatitic rocks. The names after the chemical composition.
L'aubertite, un nouveau chlorosulfate hydraté de cuivre et d'aluminium
Authors: Cesbron Fabien , Ginderow Daria , Sichère Marie-Claude , Vachey Hélène 
Published: November 2018

Aubertite is a new hydrated copper-aluminium chloro-sulfate found with copiapite, botryogene, amarantite, parabutlerite and metahohmannite at Quetena, Antofagasta province, Chile.
The mineral is triclinic with a = 6.288 Å ; b = 13.239 ; c = 6.284 ; α = 91° 52' ; β = 94° 4°' and γ = 82° 27' ; the space group is P-1. The principal d-spacing, with relative intensities and hkl values are : 6.25 (45) 001 ; 5.59 (44) 011 ; 4.83 (40) 120 ; 4.50 (100) 111 ; 4.247 (69) 101-120 ; 3.952 (58) 111 ; 3.690 (42) 121 ; 3.130 (42) 002 ; 3. 113 (40) 210. Measured density 1.815 and calculated density 1.83 g .cm-3 with Z = 1.
No crystalline forms were observed but a very good cleavage along (010). Aubertite is biaxial negative with 2 V = 71° ; refractive indices are : α (np) = 1.462 ; β (nm) = 1.482 and γ (ng) = 1.495.
The chemical analysis gave : CuO 11.80 % ; Al2O3 9.16 ; Na2O 0.13 ; K2O 0.05 ; CaO 0.18 ; SO3 28.30 ; Cl 6.70 ; H2O 45.40 ; sum 101.72 ; — O = Cl 1.51 ; sum 100.21. This gives the formula CuCl2 • CuO • Al2O3 • 4SO3 • 28H2O or CuAl (SO4)2Cl. 14H2O.
Aubertite is named from its discoverer, the geologist J. Aubert. The original specimens are deposited in the mineralogical collections of the Université P. et M. Curie and of the École nationale supérieure des Mines de Paris.
Géochimie des éléments hygromagmatophiles, coefficients de partage minéraux /liquides et propriétés structurales de ces éléments dans les liquides magmatiques
Authors: Treuil Michel , Joron Jean-Louis , Jaffrezic Henri , Villemant Benoît , Calas Georges 
Published: November 2018

The term hygromagmatophile element may be applied to those elements who maintain high stability in silicate liquid. They may be identified by (1) low crystal /liquid partition coefficient ; (2) high enrichment factors in a given differenciation series ; (3) linear correlations between the concentrations of pairs of such elements.
We propose that the behaviour of hygromagmatophile elements is governed more by the formation of stabilizing complexes in the silicate liquids than by their rejection by the crystallizing solids. When expressed in terms of possible complexes, the activity of the trace element in the liquid becomes a function that may be sensitive to small changes in chemical composition and structural state. This would explain the range of behaviour of a given trace elements in different magmatic series (basaltic, calco-alkaline, alkaline, etc.). Moreover, recent structural studies of the liquid state give factual ground to our hypothesis.
Les variations chimiques des clinopyroxènes calciques, témoins de la complexité des processus pétrogénétiques à l'intérieur d'un réservoir magmatique (Exemple des ponces des Champs Phlégréens Campanie, Italie)
Authors: Métrich Nicole 
Published: November 2018

Diopside and salite occur together in latitic and trachytic pumices in Phlegrean Fields. Optical and chemical studies by electron microprobe (Camebax) on clinopyroxenes, and optical thermometry on the two phases inclusions (glass + gaz) (which can be used to get a minimal crystallization of the host mineral) present in these crystals show that :
— diopside crystallize from a trachybasaltic melt 1,155 °C ± 10 °C,
— cognate diopsidic pyroxene exist either as phenocrysts in a latitic and trachytic pumices, or as core of salite in latitic pumice,
— inversed zoning and oscillatory zoning (with diopsidic and salitic compositions) occur in these salites,
— minimal crystallization temperatures measured on the melt inclusions are : 1,020 °C ± 10 °C, 1,040 °C ± 10 °C for more ferriferous salite in trachyte. These variations can be correlated with compositional variations of the phenocrysts.
— Melt inclusions of some apatite included in the pyroxene of trachyte point out the same temperature 1,020 °C ± 10 °C.
The results suggest the coexistence of different cogenetic magmas at different differentiation degrees. The observed compositional change from trachybasaltic and trachytic melts is consistent with a fractional crystallization process with removal of diopside and olivine in the first step then salite, plagioclase, magnetite and a more and more important role of the sanidine in the most evolved liquids. These hypotheses are in agreement with the magma chamber model proposed by Armienti et al. (in press).
Le karst des Arbailles (Pyrénées-Atlantiques, France)
Authors: Vanara Nathalie 
Published: November 2018

THE MASSIF OF ARBAILLES (WEST PYRENEES).
The Arbailles massif (200 -1 200 m) is located in the french north face of Pyrenees, Atlantic side. It forms a folded 165 square-kilometres unit of jurassic and cretaceous limestones under an oceanic climate of altitude (2000 mm/year). Observations jointly made on the surface and in the numerous underground galleries allow an occurate correlation of alternate surrective and karstic periods. The dismantled cavities and deposits pockets of the upper surface show two series of minerals, those from weathered marly-albian limestones and others supplied from the conglomerates pudding-stones of Mendibelza.
During the Miocene, the Arbailles massif is a low area of tropical erosion on the side of the main mounts. Its surrection caused the scouring of the alterites cover, the formation of fields of karstic butts and a definitive drying of the fluviatile paleosystem.
The different levels of dried valleys and the karstic hydrographie systems are successive stations of the karstic levels of origine. Paleomagnetic datations in Etxanko Zola and U/Th datations in Nébélé show that the surrection has been of about 500 m since lower Pleistocene. At the present time, water collection is made throught drainage systems without any connection to the fossil topography. Three aquifers can be distinguished : in lower cretaceous, in jurassic and in north and south limits. They are water-repellent because of more or less impermeable screens. Waters are agressive in summer and at equilibrium or lightly undersaturated the rest of the year. The modern human activities creates a recent destabilization of the environment with local erosions of grounds and an increasing turbidity of springs. An occurate study in the fail of Istaurdy allows a mesure of the effect of deforestation for the whole massif
L'âne de Buridan, le principe de Curie et l'effet-cheminée. Courant d'air dans les cavités en forme de U
Authors: Lismonde Baudouin 
Published: November 2018

The Buridan's donkey ; the principle of curie and the chimney effect (air flow in u-shaped cavity).
In a U shaped cave there is an air flow in winter. This phenomenon is a beautiful exemple of physical broken symmetry. In summer, it is possible to observe a pendulum oscillation of cold air in a U-shaped cavity.
Contribution spéléologique à la gestion durable d'un lac de montagne : traçages au-dessus du Königssee (Alpes de Berchtesgaden - Bavière - Allemagne)
Authors: Delannoy Jean-Jacques , Plassmann Guido , Apel Rolf , Kraft Hans , Nedjaï Rachid 
Published: November 2018

Ein Beitrag der Höhlenforschung zum Nachhaltigen Management eines Gebirgssees : Färbungen innerhalb des Einzugsbeckens des Königssees (Berchtesgadener Alpen, Bayern Devtschland).
Dieser Artikel hat zum Ziel die Ergebnisse von zwei Serien von Färbeversuchen im Simetsberg im Gebiet des Steinemen Meeres der ôstlichen bayerischen Kalkalpen vorzustellen.
Diese Färbeversuche hatten zum Ziel die Richtung und die Modalitaten der Karstentwässerung dieses Massivs zu bestimmen um die Verletzbarkeit des Königssees, der abgesehen von seiner hohen Wasserqualität (oligotrophes Wasser), eines der wichtigsten touristischen Ziele Bayerns darstellt. Mehr ah 800 000 Touristen besuchen jährlich die Halbinsel St. Bartholomä. Aufgrund der Lage dieses Karstes im Herzen des Nationalparks Berchtesgaden, wurde dieses Projekt von diesem Schutzgebiet in Zusammenarbeit mit französischen Karstologen geleitet. Die erste Serie von Färbeversuchen hatte zum Ziel die Entwässerung der Salzgrabenhohle, eines der wichtigsten Karstphanomene dieser Region zu definieren ; die zweite Serie bezog sich auf die Färbung von drei Seen im Steinernen Meer, von denen sich einer in unmittelbarer Nähe eines grofien Unterkunftshauses befindet das einen potentiellen Verschmutzungsherd der Oberflächenwasser und der Wasser des Endokarstes darstellt : Diese beide Aktion en haben es erlaubt zum einen die direkten hydrogeologischen Verbindungen zwischen der Entwässerung der Salzgrabenhohle und des Königssees und mm anderen den sehr transmissiven Charakter dieses Karstes nachzuweisen. Diese hohe Wasserdurchlässigkeit der tiefen Karstentwässerung nötigt zu einem konsequenten Handeln im Verskkerungsbereich um jedes Verschmutzungsrisiko des Königssees zu vermeiden.
ExoGAN: Retrieving Exoplanetary Atmospheres Using Deep Convolutional Generative Adversarial Networks
Authors: Zingales Tiziano , Waldmann Ingo P. 
Published: November 2018

Abstract
Atmospheric retrievals on exoplanets usually involve computationally intensive Bayesian sampling methods. Large parameter spaces and increasingly complex atmospheric models create a computational bottleneck forcing a trade-off between statistical sampling accuracy and model complexity. It is especially true for upcoming JWST and ARIEL observations. We introduce ExoGAN, the Exoplanet Generative Adversarial Network, a new deep-learning algorithm able to recognize molecular features, atmospheric trace-gas abundances, and planetary parameters using unsupervised learning. Once trained, ExoGAN is widely applicable to a large number of instruments and planetary types. The ExoGAN retrievals constitute a significant speed improvement over traditional retrievals and can be used either as a final atmospheric analysis or provide prior constraints to subsequent retrieval.
Structural Investigation of Silicon Carbide X Grains: Constraints on Condensation in Supernova Ejecta
Authors: Kodolányi János , Vollmer Christian , Hoppe Peter , Müller Maren 
Published: November 2018

Abstract
We analyzed seven presolar SiC grains of supernova origin (average diameter: 1–2 μm) with transmission electron microscopy. Five grains are polycrystalline, whereas two grains are single crystals. Individual crystal domains of polycrystalline grains are in epitaxial relationship, with two grains consisting almost entirely of twinned crystal domains. Most grains are free of inclusions (only one TiC inclusion and one iron- and nickel-rich inclusion were found in two separate grains). Almost all crystals have cubic symmetry (3C polytype), but we found hexagonal SiC (6H polytype) in two grains. The large range of crystal domain sizes (average diameter: 50–970 nm), as well as the larger fraction of noncubic SiC polytypes in supernova grains relative to SiC grains that crystallized in the winds of asymptotic giant branch (AGB) stars, suggest that SiC condensation in supernova ejecta occurs at a larger range of chemical and physical conditions, including supersaturation, than in the winds of AGB stars. Modeling condensation of SiC struggles to produce SiC grains as large as, or bigger than, observed here, if condensation of large (i.e., several μm in diameter) graphite grains is to precede that of SiC, which is suggested by the presolar grain record and published equilibrium condensation models. We propose that future models of graphite and SiC condensation in SN ejecta explore higher ejecta densities than before, as well as gas compositions that are more silicon- and carbon-rich. Furthermore, we infer that some supernova SiC grains may have formed without prior condensation of graphite from their parent gas.
Optimizing Pulsar Timing Array Observational Cadences for Sensitivity to Low-frequency Gravitational-wave Sources
Authors: Lam M. T. 
Published: November 2018

Abstract
Observations of low-frequency gravitational waves (GWs) will require the highest possible timing precision from an array of the most spin-stable pulsars. We can improve the sensitivity of a pulsar timing array (PTA) to different GW sources by observing pulsars with low timing noise over years to decades and distributed across the sky. We discuss observing strategies for a PTA focused on a stochastic GW background such as from unresolved supermassive black hole binaries as well as focused on single continuous-wave sources. First, we describe the method to calculate a PTA’s sensitivity to different GW-source classes. We then apply our method to the 45 pulsars presented in the North American Nanohertz Observatory for the GW 11 year data set. For expected amplitudes of the stochastic background, we find that all pulsars contribute significantly over the timescale of decades; the exception is for very pessimistic values of the stochastic-background amplitude. For individual single sources, we find that a number of pulsars contribute to the sensitivity of a given source, but that which pulsars contribute is different depending on the source, or versus an all-sky metric. Our results seem robust to the presence of red noise in pulsar arrival times. It is critical to obtain more robust pulsar-noise parameters as they heavily affect our results. Our results show that it is also imperative to locate and time as many high-precision pulsars as possible, as quickly as possible, to maximize the sensitivity of next-generation PTA detectors.
A Large Moving Group within the Lower Centaurus Crux Association
Authors: Goldman Bertrand , Röser Siegfried , Schilbach Elena , Moór Attila C. , Henning Thomas 
Published: November 2018

Abstract
Scorpius–Centaurus is the nearest OB association, and its hundreds of members are divided into subgroups, including the Lower Centaurus Crux (LCC). Here we study the dynamics of the LCC area. We report the revelation of a large moving group containing more than 1800 intermediate- and low-mass young stellar objects and brown dwarfs that escaped identification until Gaia DR2 allowed a kinematic and photometric selection to be performed. We investigate the stellar and substellar content of this moving group using the Gaia DR2 astrometric and photometric measurements. The median distance of the members is 114.5 pc, and 80% lie between 102 and 135 pc from the Sun. Our new members cover a mass range of 0.02–5 M
⊙ and add up to a total mass of about 700 M
⊙. The present-day mass function follows a log-normal law with m

c
= 0.22 M
⊙ and σ = 0.64. We find more than 200 brown dwarfs in our sample. The star formation rate had its maximum of

about 9 Myr ago. We grouped the new members into four denser subgroups, which have increasing age from 7 to 10 Myr, surrounded by “free-floating” young stars with mixed ages. Our isochronal ages, now based on accurate parallaxes, are compatible with several earlier studies of the region. The whole complex is presently expanding, and the expansion started between 8 and 10 Myr ago. Two hundred members show infrared excess compatible with circumstellar disks from full to debris disks. This discovery provides a large sample of nearby young stellar and substellar objects for disk and exoplanet studies.
Bunching Coherent Curvature Radiation in Three-dimensional Magnetic Field Geometry: Application to Pulsars and Fast Radio Bursts
Authors: Yang Yuan-Pei , Zhang Bing 
Published: November 2018

Abstract
The extremely high brightness temperatures of pulsars and fast radio bursts (FRBs) require their radiation mechanisms to be coherent. Coherent curvature radiation from bunches has been long discussed as the mechanism for radio pulsars and recently for FRBs. Assuming that bunches are already generated in pulsar magnetospheres, we calculate the spectrum of coherent curvature radiation under a three-dimensional magnetic field geometry. Different from previous works assuming parallel trajectories and a monoenergetic energy distribution of electrons, we consider a bunch characterized by its length, curvature radius of the trajectory family, bunch opening angle, and electron energy distribution. We find that the curvature radiation spectra of the bunches are characterized by a multisegment broken power law, with the break frequencies depending on bunch properties and trajectory configuration. We also emphasize that in a pulsar magnetosphere, only the fluctuation of net charges with respect to the background (Goldreich–Julian) outflow can make a contribution to coherent radiation. We apply this model to constrain the observed spectra of pulsars and FRBs. For a typical pulsar (

, P = 0.1 s), a small fluctuation of the net charge δn
GJ ∼ 0.1n
GJ can provide the observable flux. For FRBs, the fluctuating net charge may be larger due to its abrupt nature. For δn
GJ ∼ n
GJ, a neutron star with a strong magnetic field and fast rotation is required to power an FRB in the spindown-powered model. The requirement is less stringent in the cosmic comb model thanks to the larger cross section and compressed charge density of the bunch made by the external astrophysical stream that combs the magnetosphere.
The Dynamical Mass and Evolutionary Status of the Type II Cepheid in the Eclipsing Binary System OGLE-LMC-T2CEP-211 with a Double-ring Disk*

†
Authors: Pilecki Bogumił , Dervişoğlu Ahmet , Gieren Wolfgang , Smolec Radosław , Soszyński Igor , Pietrzyński Grzegorz , Thompson Ian B. , Taormina Mónica 
Published: November 2018

Abstract
We present the analysis of a peculiar W Virginis (pWVir) type II Cepheid, OGLE-LMC-T2CEP-211 (P
puls = 9.393 days), in a double-lined binary system (P
orb = 242 days), which shed light on virtually unknown evolutionary status and structure of pWVir stars. The dynamical mass of the Cepheid (first ever for a type II Cepheid) is 0.64 ± 0.02 M
⊙, and the radius R = 25.1 ± 0.3 R
⊙. The companion is a massive (5.67 M
⊙) main-sequence star obscured by a disk. Such a configuration suggests a mass transfer in the system history. We found that originally the system (

= 12 days) was composed of 3.5 and 2.8 M
⊙ stars, with the current Cepheid being more massive. The system age is now ∼200 Myr, and the Cepheid is almost completely stripped of hydrogen, with helium mass of ∼92% of the total mass. It finished transferring the mass 2.5 Myr ago and is evolving toward lower temperatures passing through the instability strip. Comparison with observations indicates a reasonable 2.7 × 10−8
M
⊙ yr−1 mass loss from the Cepheid. The companion is most probably a Be main-sequence star with T = 22,000 K and R = 2.5 R
⊙. Our results yield a good agreement with a pulsation theory model for a hydrogen-deficient pulsator, confirming the described evolutionary scenario. We detected a two-ring disk (R
disk ∼ 116 R
⊙) and a shell (R
shell ∼ 9 R
⊙) around the companion, which is probably a combination of the matter from the past mass transfer, the mass being lost by the Cepheid owing to wind and pulsations, and a decretion disk around a rapidly rotating secondary. Our study, together with observational properties of pWVir stars, suggests that the majority of them are products of a similar binary evolution interaction.
Model-independent Curvature Determination from Gravitational-wave Standard Sirens and Cosmic Chronometers
Authors: Wei Jun-Jie 
Published: November 2018

Abstract
The detection of gravitational waves (GWs) provides a direct way to measure the luminosity distance, which enables us to probe cosmology. In this paper, we continue to expand the application of GW standard sirens in cosmology, and propose that the spatial curvature can be estimated in a model-independent way by comparing the distances from future GW sources and current cosmic-chronometer observations. We expect an electromagnetic counterpart of the GW event to give the source redshift, and simulate hundreds of GW data from the coalescence of double neutron stars and black hole–neutron star binaries using the Einstein Telescope as a reference. Our simulations show that, from 100 simulated GW events and 31 current cosmic-chronometer measurements, the error of the curvature parameter Ω
K
is expected to be constrained at the level of ∼0.125. If 1000 GW events were observed, the uncertainty of Ω
K
would be further reduced to ∼0.040. We also find that adding 50 mock H(z) data points (consisting of 81 cosmic-chronometer data points and 1000 simulated GW events) could result in a much tighter constraint on the zero cosmic curvature, for which Ω
K
= −0.002 ± 0.028. Compared to some actual model-independent curvature tests involving distances from other cosmic probes, this method using GW data achieves constraints with much higher precision.
Diffusion and Concentration of Solids in the Dead Zone of a Protoplanetary Disk
Authors: Yang 楊朝 Chao-Chin 欽 , Mac Low Mordecai-Mark , Johansen Anders 
Published: November 2018

Abstract
The streaming instability is a promising mechanism to drive the formation of planetesimals in protoplanetary disks. To trigger this process, it has been argued that sedimentation of solids onto the mid-plane needs to be efficient, and therefore that a quiescent gaseous environment is required. It is often suggested that dead-zone or disk-wind structure created by non-ideal magnetohydrodynamical (MHD) effects meets this requirement. However, simulations have shown that the mid-plane of a dead zone is not completely quiescent. In order to examine the concentration of solids in such an environment, we use the local-shearing-box approximation to simulate a particle-gas system with an Ohmic dead zone including mutual drag force between the gas and the solids. We systematically compare the evolution of the system with ideal or non-ideal MHD, with or without backreaction drag force from particles on gas, and with varying solid abundances. Similar to previous investigations of dead-zone dynamics, we find that particles of dimensionless stopping time

do not sediment appreciably more than those in ideal magnetorotational turbulence, resulting in a vertical scale height an order of magnitude larger than in a laminar disk. Contrary to the expectation that this should curb the formation of planetesimals, we nevertheless find that strong clumping of solids still occurs in the dead zone when solid abundances are similar to the critical value for a laminar environment. This can be explained by the weak radial diffusion of particles near the mid-plane. The results imply that the sedimentation of particles to the mid-plane is not a necessary criterion for the formation of planetesimals by the streaming instability.