bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of temperature, pressure, and oxygen fugacity on the electrical conductivity of dry eclogite, and geophysical implications
Authors: Dai Lidong , Hu Haiying , Li Heping , Wu Lei , Hui Keshi , Jiang Jianjun , Sun Wenqing 
Published: May 2016

AbstractThe electrical conductivity of eclogite was measured at temperatures of 873–1173 K and pressures of 1.0–3.0 GPa within a frequency range of 0.1–106 Hz using a YJ‐3000t multianvil press and Solartron‐1260 impedance/gain‐phase analyzer. Three solid‐state oxygen buffers (Cu + CuO, Ni + NiO, and Mo + MoO2) were employed to control the oxygen fugacity. Experimental results indicate that the electrical conductivity of the samples tended to increase with increasing temperature, conforming to an Arrhenius relation. Under the control of a Cu + CuO oxygen buffer, the electrical conductivity of the eclogite decreased with a rise in pressure, and its corresponding activation volume and activation energy at atmospheric pressure were calculated as −2.51 ± 0.29 cm3/mole and 0.86 ± 0.12 eV, respectively. At 2.0 GPa, the electrical conductivity of the eclogite increased with increasing oxygen fugacity, and the preexponential factor increased while the activation enthalpy decreased. The observed positive exponential factor for the dependence of electrical conductivity on oxygen fugacity, as well as the negative activation volume, confirm that the hopping of small polarons is the dominant conduction mechanism in eclogite at high temperatures and pressures. Our results suggest that the electrical conductivity of dry eclogite under various redox conditions cannot explain the high anomalies in conductivity under stable midlower continental crust and under the Dabie‐Sulu ultrahigh‐pressure metamorphic belt of eastern China.
High temporal resolution observations of auroral electron density using superthermal electron enhancement of Langmuir waves
Authors: Vierinen Juha , Bhatt Asti , Hirsch Michael A. , Strømme Anja , Semeter Joshua L. , Zhang Shun‐Rong , Erickson Philip J. 
Published: May 2016

AbstractWe report high temporal resolution auroral electron precipitation observations using the Sondrestrom incoherent scatter radar. The observations make use of the superthermal electron enhancement of Langmuir waves, which is shown to give accurate observations of the electron density during auroral ionization at a subsecond temporal resolution. This is important when matching to the time scales of auroral precipitation‐related phenomena, such as energy input into the atmosphere and magnetospheric electron acceleration mechanisms. We describe the measurement technique and show an example observation of auroral precipitation. The results show transients in electron density in the order of a few seconds, which are fully resolved by the plasma line measurements. An electron precipitation model is used to estimate precipitation energy and flux density. The energetic electron flux during the example event has variations even at short time scales. The results show that electron density profiles derived from plasma lines can be a powerful new observational capability.
Milne‐Eddington inversion for unresolved magnetic structures in the quiet Sun photosphere
Authors: Bommier Véronique 
Published: May 2016

AbstractThis paper is first devoted to present our method for modeling unresolved magnetic structures in the Milne‐Eddington inversion of spectropolarimetric data. The related definitions and other approaches and different used inversion algorithms are recalled for comparison. In a second part, we apply our method to quiet Sun data outside active regions. We obtain the quiet Sun photospheric magnetic field as composed of unresolved opening and connected magnetic flux tubes, which form a loop carpet of field lines. We then analyze the spatial correlation, which we also observed for the magnetic field vector, in terms of flux tube diameter, distance, and field strength. We find that different observations with the Zurich imaging polarimeter and THEMIS polarimeter mounted on the THEMIS telescope give very close results, and we add results also very close derived from HINODE/Solar Optical Telescope/spectropolarimeter observations analyzed with the same method. We obtain a mean flux tube diameter of 30 km, a mean flux tube distance of 230 km, and a mean flux tube magnetic field of 1.3 kG.
Compressional ULF wave modulation of energetic particles in the inner magnetosphere
Authors: Liu H. , Zong Q.‐G. , Zhou X.‐Z. , Fu S. Y. , Rankin R. , Wang L.‐H. , Yuan C. J. , Wang Y. F. , Baker D. N. , Blake J. B. , Kletzing C. A. 
Published: May 2016

AbstractWe present Van Allen Probes observations of modulations in the flux of very energetic electrons up to a few MeV and protons between 1200 and 1400 UT on 19 February 2014. During this event the spacecraft were in the dayside magnetosphere at L⋆≈5.5. The modulations extended across a wide range of particle energies, from 79.80 keV to 2.85 MeV for electrons and from 82.85 keV to 636.18 keV for protons. The fluxes of π/2 pitch angle particles were observed to attain maximum values simultaneously with the ULF compressional magnetic field component reaching a minimum. We use peak‐to‐valley ratios to quantify the strength of the modulation effect, finding that the modulation is larger at higher energies than at lower energies. It is shown that the compressional wave modulation of the particle distribution is due to the mirror effect, which can trap relativistic electrons efficiently for energies up to 2.85 MeV and trap protons up to ≈600 keV. Larger peak‐to‐valley ratios at higher energies also attributed to the mirror effect. Finally, we suggest that protons with energies higher than 636.18 keV cannot be trapped by the compressional ULF wave efficiently due to the finite Larmor radius effect.
On subsurface cooling associated with the Biobio River Canyon (Chile)
Authors: Sobarzo Marcus , Saldías Gonzalo S. , Tapia Fabian J. , Bravo Luis , Moffat Carlos , Largier John L. 
Published: May 2016

AbstractSubmarine canyons cutting across the continental shelf can modulate the cross‐shelf circulation being effective pathways to bring water from the deep ocean onto the shelf. Here, we use 69 days of moored array observations of temperature and ocean currents collected during the spring of 2013 and winter‐spring 2014, as well as shipboard hydrographic surveys and sea‐level observations to characterize cold, oxygen poor, and nutrient‐rich upwelling events along the Biobio Submarine Canyon (BbC). The BbC is located within the Gulf of Arauco at 36° 50'S in the Central Chilean Coast. The majority of subtidal temperature at 150 m depth is explained by subtidal variability in alongshore currents on the canyon with a lag of less than a day (r2 = 0.65). Using the vertical displacement of the 10° and 10.5°C isotherms, we identified nine upwelling events, lasting between 20 h to 4.5 days, that resulted in vertical isothermal displacements ranging from 29 to 137 m. The upwelled water likely originated below 200 m. Majority of the cooling events were related with strong northward (opposite Kelvin wave propagation) flow and low pressure at the coast. Most of these low pressure events occur during relatively weak local wind forcing conditions, and were instead related with Coastal Trapped Waves (CTWs) propagating southwards from lower latitudes. These cold, high‐nutrient, low‐oxygen waters may be further upwelled and advected into the Gulf of Arauco by wind forcing. Thus, canyon upwelling may be a key driver of biological productivity and oxygen conditions in this Gulf.
Magnetic anomalies concentrated near and within Mercury's impact basins: Early mapping and interpretation
Authors: Hood L. L. 
Published: May 2016

AbstractNinety‐five low‐altitude passes of MErcury Surface, Space ENvironment, GEochemistry, and Ranging magnetometer data from February, March, and April of 2015 have been applied to produce an approximate map of the crustal magnetic field at a constant altitude of 40 km covering latitudes of 35°–75°N and longitudes of 90°–270°E. Anomalies are concentrated near and within the Caloris impact basin. A smaller concentration occurs over and around Sobkou Planitia and an associated older large impact basin. The strongest anomalies are found within Caloris and are distributed in a semicircular arc that is roughly concentric with the basin rim. They imply the existence of a core dynamo at the time when Caloris formed (∼3.9 Gyr ago). Anomalies over high‐reflectance volcanic plains are relatively weak while anomalies over low‐reflectance material that has been reworked by impact processes are relatively strong. The latter characteristics are qualitatively consistent with the ejecta deposit model for anomaly sources.
A semi‐adaptive control approach to closed‐loop medication infusion
Authors: Jin Xin , Kim Chang‐Sei , Dumont Guy A. , Ansermino J. Mark , Hahn Jin‐Oh 
Published: May 2016

SummaryThis paper presents a semi‐adaptive control approach to closed‐loop medication infusion problems. The rationale underlying this approach is to design a controller that can adapt model parameters with a large impact on the model's fidelity while fixing the remaining parameters at nominal values. In this paper, a control‐oriented model for this purpose is derived via system identification and sensitivity analysis of a low‐order model capturing the direct dose‐response relationship Using the model thus derived, a model‐reference adaptive controller and a composite adaptive controller are designed and compared with each other. In‐silico simulation results using remifentanil's effect on respiratory rate as an example indicate that both controllers can regulate the output at commanded set points. Copyright © 2016 John Wiley & Sons, Ltd.
Spatial variation of dental caries in late holocene samples of Southern South America: A geostatistical study
Authors: Menéndez Lumila Paula 
Published: May 2016

ABSTRACTObjectiveThe spatial variation of dental caries in late Holocene southern South American populations will be analyzed using geostatistical methods. The existence of a continuous geographical pattern of dental caries variation will be tested.MethodsThe author recorded dental caries in 400 individuals, collated this information with published caries data from 666 additional individuals, and calculated a Caries Index. The caries spatial distribution was evaluated by means of 2D maps and scatterplots. Geostatistical analyses were performed by calculating Moran's I, correlograms and a Procrustes analysis.ResultsThere is a relatively strong latitudinal continuous gradient of dental caries variation, especially in the extremes of the distribution. Moreover, the association between dental caries and geography was relatively high (m12 = 0.6). Although northern and southern samples had the highest and lowest frequencies of dental caries, respectively, the central ones had the largest variation and had lower rates of caries than expected.ConclusionThe large variation in frequencies of dental caries in populations located in the center of the distribution could be explained by their subsistence strategies, characterized either by the consumption of wild cariogenic plants or cultigens (obtained locally or by exchange), a reliance on fishing, or the incorporation of plants rich in starch rather than carbohydrates. It is suggested that dental caries must be considered a multifactorial disease which results from the interaction of cultural practices and environmental factors. This can change how we understand subsistence strategies as well as how we interpret dental caries rates. Am. J. Hum. Biol., 2016. © 2016 Wiley Periodicals, Inc. Am. J. Hum. Biol. 28:825–836, 2016. © 2016Wiley Periodicals, Inc.
Divergent Synthesis of 3,3‐Disubstituted Oxindoles Initiated by Palladium‐Catalyzed Intramolecular Arylation of Unsaturated Amides
Authors: Wei Fang , Wei Lei , Zhou Ling , Tung Chen‐Ho , Ma Yudao , Xu Zhenghu 
Published: May 2016

Abstract3,3‐Disubstituted oxindole derivatives are privileged five‐membered heterocycles widely presented in a variety of natural products and pharmaceuticals with significant biological activities. In this paper, diverse boron‐substituted oxindoles have been successfully synthesized by Pd‐catalyzed intramolecular arylation and borylation cascade of unsaturated amides. More importantly, simply switching the reaction solvents led to other reductive Heck products with the same catalyst and reactants. Control experiments showed that the reductive Heck products were transformed from 3,3‐disubstituted oxindole boronic esters in the presence of base.
Solvent‐Mediated Control of the Electrochemical Discharge Products of Non‐Aqueous Sodium–Oxygen Electrochemistry
Authors: Aldous Iain M. , Hardwick Laurence J. 
Published: May 2016

AbstractThe reduction of dioxygen in the presence of sodium cations can be tuned to give either sodium superoxide or sodium peroxide discharge products at the electrode surface. Control of the mechanistic direction of these processes may enhance the ability to tailor the energy density of sodium–oxygen batteries (NaO2: 1071 Wh kg−1 and Na2O2: 1505 Wh kg−1). Through spectroelectrochemical analysis of a range of non‐aqueous solvents, we describe the dependence of these processes on the electrolyte solvent and subsequent interactions formed between Na+ and O2−. The solvents ability to form and remove [Na+‐O2−]ads based on Gutmann donor number influences the final discharge product and mechanism of the cell. Utilizing surface‐enhanced Raman spectroscopy and electrochemical techniques, we demonstrate an analysis of the response of Na‐O2 cell chemistry with sulfoxide, amide, ether, and nitrile electrolyte solvents.
Hofmeister‐Effekte unter der Lupe: Die direkte Anion‐Amid‐Bindung ist schwächer als die Kation‐Amid‐Bindung
Authors: Balos Vasileios , Kim Heejae , Bonn Mischa , Hunger Johannes 
Published: May 2016

AbstractTrotz vermehrter Hinweise auf direkte Wechselwirkungen als Ursache für die Destabilisierung von Proteinen durch Ionen blieb die Frage nach der Stärke der Bindung von Anionen zu Proteinen im Vergleich zu jener von Kationen offen. Die Rotation eines Modellamids wurde nun als Maß für die Wechselwirkung verschiedener Anionen mit der Amidgruppe verwendet. Die Untersuchungen zeigen, dass Protein‐stabilisierende Salze wie KCl und KNO3 die Rotationsmobilität des Amids nicht beeinflussen. Umgekehrt reduzieren denaturierende Salze wie KSCN und KI die Rotationsfreiheitsgrade der Amidgruppe merklich. Diese Beobachtungen liefern den Nachweis für eine Proteindenaturierung durch direkte Ion‐Protein‐Kontakte. Der Vergleich dieser Daten mit denjenigen für die entsprechenden Kation‐Amid‐Wechselwirkungen zeigt, dass – entgegen der weit verbreiteten Meinung – die Anion‐Amid‐ schwächer als die Kation‐Amid‐Bindung ist.
Organokatalytische Synthese von enantiomerenreinen 2H‐ und 3H‐Pyrrolen: Inhibitoren des Hedgehog‐Signalwegs
Authors: Kötzner Lisa , Leutzsch Markus , Sievers Sonja , Patil Sumersing , Waldmann Herbert , Zheng Yiying , Thiel Walter , List Benjamin 
Published: May 2016

AbstractEs wird über die organokatalytische divergente Synthese von enantiomerenreinen 2H‐ und 3H‐Pyrrolen, unter Verwendung einer Fischer‐Indolisierung und einer [1,5]‐Alkyl‐Verschiebung, berichtet. Katalysiert durch die chirale Phosphorsäure STRIP konnten die entsprechenden Produkte in guten bis exzellenten Ausbeuten sowie Enantioselektivitäten erhalten werden. Bemerkenswerterweise zeigten biologische Untersuchungen, dass eines der neuartigen 2H‐Pyrrole ein potenter aber nicht toxischer Inhibitor des Hedgehog‐Signalwegs ist und an das Smoothened‐Protein bindet.
Observation of Spontaneous C=C Bond Breaking in the Reaction between Atomic Boron and Ethylene in Solid Neon
Authors: Jian Jiwen , Lin Hailu , Luo Mingbiao , Chen Mohua , Zhou Mingfei 
Published: May 2016

AbstractA ground‐state boron atom inserts into the C=C bond of ethylene to spontaneously form the allene‐like compound H2CBCH2 on annealing in solid neon. This compound can further isomerize to the propyne‐like HCBCH3 isomer under UV light excitation. The observation of this unique spontaneous C=C bond insertion reaction is consistent with theoretical predictions that the reaction is thermodynamically exothermic and kinetically facile. This work demonstrates that the stronger C=C bond, rather than the less inert C−H bond, can be broken to form organoboron species from the reaction of a boron atom with ethylene even at cryogenic temperatures.
Selective Catalytic Synthesis Using the Combination of Carbon Dioxide and Hydrogen: Catalytic Chess at the Interface of Energy and Chemistry
Authors: Klankermayer Jürgen , Wesselbaum Sebastian , Beydoun Kassem , Leitner Walter 
Published: May 2016

AbstractThe present Review highlights the challenges and opportunities when using the combination CO2/H2 as a C1 synthon in catalytic reactions and processes. The transformations are classified according to the reduction level and the bond‐forming processes, covering the value chain from high volume basic chemicals to complex molecules, including biologically active substances. Whereas some of these concepts can facilitate the transition of the energy system by harvesting renewable energy into chemical products, others provide options to reduce the environmental impact of chemical production already in today's petrochemical‐based industry. Interdisciplinary fundamental research from chemists and chemical engineers can make important contributions to sustainable development at the interface of the energetic and chemical value chain. The present Review invites the reader to enjoy this exciting area of “catalytic chess” and maybe even to start playing some games in her or his laboratory.
The Organocatalytic Approach to Enantiopure 2H‐ and 3H‐Pyrroles: Inhibitors of the Hedgehog Signaling Pathway
Authors: Kötzner Lisa , Leutzsch Markus , Sievers Sonja , Patil Sumersing , Waldmann Herbert , Zheng Yiying , Thiel Walter , List Benjamin 
Published: May 2016

AbstractA divergent approach to enantioenriched 2H‐ and 3H‐pyrroles catalyzed by a spirocyclic phosphoric acid is reported that makes use of a Fischer‐type indolization and a [1,5]‐alkyl shift. Catalyzed by the chiral phosphoric acid STRIP, good to excellent yields and enantioselectivities could be obtained. Remarkably, biological evaluation reveals one of these novel 2H‐pyrroles to be a potent but nontoxic inhibitor of the Hedgehog signaling pathway by binding to the Smoothened protein.
Study on the preparation, characterization, and release behavior of carbosulfan/polyurethane microcapsules
Authors: Xu Yong , Wang Liying , Tong Yujia , Xiang Sheng , Guo Xinyu , Li Jing , Gao Haixiang , Wu Xuemin 
Published: May 2016

ABSTRACTPolyurethane, a controlled release material, has been widely applied in many fields due to its high thermal and mechanical stability, corrosion resistance, and low cost. In this article, we prepared carbosulfan/polyurethane microcapsules by an interfacial polymerization method using modified isocyanate as the precursor and triethanolamine as a curing agent. The microcapsules were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis, and their release kinetics, chemical stability, and the safety of wheat seeds coating were also detected. The microcapsules had an excellent encapsulation efficiency and loading ability for carbosulfan ∼96.23% and 50%, respectively. Furthermore, the microcapsules improved the chemical stability of the carbosulfan and exhibited an excellent sustained release property (above 30 days), which controlled the carbosulfan and carbofuran at an appropriate level for reducing the adverse effects on the environment and agricultural products. The coated wheat seeds germination rate test showed that compared with the emulsifiable concentrate, the microcapsules almost had no effect on the germination rate, plant height, and root length. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43844.
Development of an encapsulated phase change material via emulsion and coaxial electrospinning
Authors: Chalco‐Sandoval Wilson , Fabra María José , López‐Rubio Amparo , Lagaron Jose M. 
Published: May 2016

ABSTRACTThis article reports on the encapsulation of a phase change material (PCM) into a hydrophilic polymer, poly(vinyl alcohol) (PVOH), by means of electrospinning. Different strategies were carried out to improve the thermal buffering capacity and the stability of the developed structures when they were exposed to different relative humidity (RH) conditions. On the one hand, the thermal energy storage capacity of PVOH/PCM structures obtained through emulsion electrospinning was optimized by using different amounts of polyoxyethylene sorbitan monolaureate (Tween 20). Surfactant addition successfully increased the heat storage capacity of the developed structures, reaching an optimum performance at a concentration of 0.32% in weight with respect to the total emulsion weight. However, the hydrophilic nature of the developed structures made them extremely difficult to handle due to swelling with increasing RH. To avoid this issue an additional shell layer of poly(caprolactone) (PCL), was applied by coaxial electrospinning. In this case, the PVOH/PCM ratio (core) was optimized to reach the highest heat storage capacity per gram of sample and, then, a PCL solution was used as a shell material to hydrophobize the structures. The optimized coaxial electrospun structures were able to encapsulate about 82% of PCM. The use of both emulsion and coaxial electrospinning strategies are introduced here for the first time as advanced strategies to overcome application issues such as unintended migration and performance drop in the previously developed monophase materials. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43903.
Enhanced Thermoelectric Properties of Polyaniline Nanofilms Induced by Self‐Assembled Supramolecules
Authors: Wang Liming , Yao Qin , Xiao Juanxiu , Zeng Kaiyang , Shi Wei , Qu Sanyin , Chen Lidong 
Published: May 2016

AbstractPolyaniline (PANI) is one of the most promising candidates for flexible organic thermoelectric (TE) applications owing to its relatively low cost and high stability. Herein, the self‐assembled supramolecule (SAS) (3,6‐dioctyldecyloxy‐1,4‐benzenedicarboxylic acid) was used as an additive and was introduced into PANI films as a template. Raman spectroscopy, X‐ray diffraction, and conductive atomic force microscopy analyses demonstrated that the highly ordered chain structure of PANI was achieved by chemical interactions between PANI and the SAS. Moreover, the ordered regions in the PANI‐SAS film increased with a decrease in the film thickness. Consequently, the TE properties of PANI‐SAS films were not only much higher than those of PANI films, but they also increased with a decrease in film thickness. The maximum TE power factor of the PANI‐SAS film reached 31 μW m−1 K−2, which is approximately six times higher than the power factor of a PANI film with a similar thickness. This work offers a promising way to prepare PANI thin films with enhanced TE properties.
Silver(I)‐Catalyzed Three‐Component Reaction of Propargylic Alcohols, Carbon Dioxide and Monohydric Alcohols: Thermodynamically Feasible Access to β‐Oxopropyl Carbonates
Authors: Zhou Zhi‐Hua , Song Qing‐Wen , Xie Jia‐Ning , Ma Ran , He Liang‐Nian 
Published: May 2016

AbstractA silver(I)‐catalyzed three‐component reaction of propargylic alcohols, CO2, and monohydric alcohols was successfully developed for the synthesis of β‐oxopropyl carbonates. As such, a series of β‐oxopropyl carbonates were exclusively produced in excellent yields (up to 98 %), even under atmospheric pressure of CO2. The silver catalyst works efficiently for both the carboxylative cyclization of propargylic alcohols with CO2 and subsequent transesterification of α‐alkylidene cyclic carbonates with monohydric alcohols; thus this tandem process performs smoothly under mild conditions. This work provides a versatile and thermodynamically favorable approach to dissymmetric dialkyl carbonates.