bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ionospheric flow structures associated with auroral beading at substorm auroral onset
Authors: Gallardo‐Lacourt Bea , Nishimura Y. , Lyons L. R. , Ruohoniemi J. M. , Donovan E. , Angelopoulos V. , McWilliams K. A. , Nishitani N. 
Published: October 2014

AbstractAuroral observations have shown that brightening at substorm auroral onset often consists of azimuthally propagating beads forming along a preexisting arc. However, the ionospheric flow structure related to this wavy auroral structure has been poorly understood. We investigated ionospheric flow patterns associated with auroral onset beads using line‐of‐sight flow observations from the Super Dual Auroral Radar Network (SuperDARN) and auroral images from the Time History of Events and Macroscale Interactions during Substorms (THEMIS) ground‐based all‐sky‐imager (ASI) array. We selected events when SuperDARN radars operated in a high temporal resolution THEMIS mode (6 s) along northward looking beams, a time resolution comparable to that of the imagers, providing a unique tool to detect properties of flows associated with the substorm onset instability. We have found very fast oscillating flows (~1000 m/s) that are correlated with the onset beads propagating across the THEMIS‐mode beam meridian. Two‐dimensional radar measurements also show a wavy pattern in the azimuthal direction with a wavelength of ~78 km, which is close to the azimuthal separation of individual beads. We also used an imager and SuperDARN in Iceland and identified weak but significant azimuthal flow modulations associated with beads. These strong correlations (in time and space) between auroral beading and the fast ionospheric flows suggest that substorm onset occurs via an instability in the inner plasma sheet and is associated with intense flow shears. The flow shear is clockwise around auroral beads, consistent with converging electric fields associated with upward field‐aligned currents in the shear center.
DEMETER observations of bursty MF emissions and their relation to ground‐level auroral MF burst
Authors: Broughton M. C. , LaBelle J. , Parrot M. 
Published: October 2014

AbstractA survey of medium frequency (MF) electric field data from selected orbits of the Detection of Electro‐Magnetic Emissions Transmitted from Earthquakes (DEMETER) spacecraft reveals 68 examples of a new type of bursty MF emissions occurring at high latitudes associated with auroral phenomena. These resemble auroral MF burst, a natural radio emission observed at ground level near local substorm onsets. Similar to MF burst, the bursty MF waves observed by DEMETER have broadband, impulsive frequency structure covering 1.5–3.0 MHz, amplitudes of 50–100 μV/m, an overall occurrence rate of ∼0.76% with higher occurrence during active times, and strong correlation with auroral hiss. The magnetic local time distribution of the MF waves observed by DEMETER shows peak occurrence rate near 18 MLT, somewhat earlier than the equivalent peak in the occurrence rate of ground level MF burst, though propagation effects and differences in the latitudes sampled by the two techniques may explain this discrepancy. Analysis of solar wind and SuperMAG data suggests that while the bursty MF waves observed by DEMETER are associated with enhanced auroral activity, their coincidence with substorm onset may not be as exact as that of ground level MF burst. One conjunction occurs in which MF burst is observed at Churchill, Manitoba, within 8 min of MF emissions detected by DEMETER on field lines approximately 1000 km southeast of Churchill. These observations may plausibly be associated with the same auroral event detected by ground level magnetometers at several Canadian observatories. Although it is uncertain, the balance of the evidence suggests that the bursty MF waves observed with DEMETER are the same phenomenon as the ground level MF burst. Hence, theories of MF burst generation in the ionosphere, such as beam‐generated Langmuir waves excited over a range of altitudes or strong Langmuir turbulence generating a range of frequencies within a narrow altitude range, need to be revisited to see whether they predict in situ detection of MF burst.
Frictional heterogeneities on carbonate‐bearing normal faults: Insights from the Monte Maggio Fault, Italy
Authors: Carpenter B. M. , Scuderi M. M. , Collettini C. , Marone C. 
Published: October 2014

AbstractObservations of heterogeneous and complex fault slip are often attributed to the complexity of fault structure and/or spatial heterogeneity of fault frictional behavior. Such complex slip patterns have been observed for earthquakes on normal faults throughout central Italy, where many of the Mw 6 to 7 earthquakes in the Apennines nucleate at depths where the lithology is dominated by carbonate rocks. To explore the relationship between fault structure and heterogeneous frictional properties, we studied the exhumed Monte Maggio Fault, located in the northern Apennines. We collected intact specimens of the fault zone, including the principal slip surface and hanging wall cataclasite, and performed experiments at a normal stress of 10 MPa under saturated conditions. Experiments designed to reactivate slip between the cemented principal slip surface and cataclasite show a 3 MPa stress drop as the fault surface fails, then velocity‐neutral frictional behavior and significant frictional healing. Overall, our results suggest that (1) earthquakes may readily nucleate in areas of the fault where the slip surface separates massive limestone and are likely to propagate in areas where fault gouge is in contact with the slip surface; (2) postseismic slip is more likely to occur in areas of the fault where gouge is present; and (3) high rates of frictional healing and low creep relaxation observed between solid fault surfaces could lead to significant aftershocks in areas of low stress drop.
Current plate boundary deformation of the Afar rift from a 3‐D velocity field inversion of InSAR and GPS
Authors: Pagli Carolina , Wang Hua , Wright Tim J. , Calais Eric , Lewi Elias 
Published: October 2014

AbstractExtension, faulting, and magmatism are the main controls on the magnitude and localization of strain at mid‐ocean ridges. However, the temporal and spatial patterns of such processes are not clear since the strain distribution has not been resolved in the past at sufficient spatial resolution and over extended areas. Interferometric synthetic aperture radar (InSAR) and GPS data with unprecedented resolution are now available to us from the Afar rift of Ethiopia. Here we use a velocity field method to combine InSAR and GPS to form the first high‐resolution continuous three‐dimensional velocity field of Afar. We study an area that is 500 km wide and 700 km long, covering three branches of the Afar continental rift and their triple junctions. Our velocity field shows that plate spreading is currently achieved in Afar in contrasting modes. A transient postdiking deformation is focused at the Dabbahu rift segment, while in central Afar, spreading is distributed over several overlapping segments and southern Afar exhibits an interdiking deformation pattern focused at the Asal–Ghoubbet segment. We find that current spreading rates at Dabbahu, following the 2005–2010 intrusions, are up to 110 mm/yr, 6 times larger than the long‐term plate divergence. A segment‐centered uplift of up to 80 mm/yr also occurs, indicating that magma flow is still a primary mechanism of deformation during postdiking. On the other hand, no vertical displacements are currently observed in central and southern Afar, suggesting lack of significant magmatic activity at shallow levels.
Behavior of multitemporal and multisensor passive microwave indices in Southern Hemisphere ecosystems
Authors: Barraza Veronica , Grings Francisco , Ferrazzoli Paolo , Huete Alfredo , Restrepo‐Coupe Natalia , Beringer Jason , Van Gorsel Eva , Karszenbaum Haydee 
Published: October 2014

AbstractThis study focused on the time series analysis of passive microwave and optical satellite data collected from six Southern Hemisphere ecosystems in Australia and Argentina. The selected ecosystems represent a wide range of land cover types, including deciduous open forest, temperate forest, tropical and semiarid savannas, and grasslands. We used two microwave indices, the frequency index (FI) and polarization index (PI), to assess the relative contributions of soil and vegetation properties (moisture and structure) to the observations. Optical‐based satellite vegetation products from the Moderate Resolution Imaging Spectroradiometer were also included to aid in the analysis. We studied the X and Ka bands of the Advanced Microwave Scanning Radiometer‐EOS and Wind Satellite, resulting in up to four observations per day (1:30, 6:00, 13:30, and 18:00 h). Both the seasonal and hourly variations of each of the indices were examined. Environmental drivers (precipitation and temperature) and eddy covariance measurements (gross ecosystem productivity and latent energy) were also analyzed. It was found that in moderately dense forests, FI was dependent on canopy properties (leaf area index and vegetation moisture). In tropical woody savannas, a significant regression (R2) was found between FI and PI with precipitation (R2 > 0.5) and soil moisture (R2 > 0.6). In the areas of semiarid savanna and grassland ecosystems, FI variations found to be significantly related to soil moisture (R2 > 0.7) and evapotranspiration (R2 > 0.5), while PI varied with vegetation phenology. Significant differences (p < 0.01) were found among FI values calculated at the four local times.
Calibration of stable isotope composition of Thoracosphaera heimii (dinoflagellate) calcite for reconstructing paleotemperatures in the intermediate photic zone
Authors: Minoletti Fabrice , Hermoso Michaël , Candelier Yaël , Probert Ian 
Published: October 2014

AbstractIn this study we investigate the temperature dependence of oxygen isotope ratios preserved in calcite formed by the dinoflagellate Thoracosphaera heimii, focusing primarily on the development of a geological proxy. Geochemical analysis of the calcite shells produced by this species represents a valuable proxy for reconstructing environmental conditions in the intermediate photic zone. Calibration is based on isotopic analysis from culture experiments performed in very dilute batch conditions, as well as from near‐monospecific T. heimii assemblages separated from core top sediments. Results are similar for both approaches and indicate that T. heimii shells have oxygen isotope compositions close to equilibrium values predicted for inorganic calcite precipitation. This calibration of the isotopic composition of dinoflagellate calcite indicates that monospecific assemblages of T. heimii can be used to unravel paleotemperatures in the intermediate photic zone by applying isotopic transfer functions for equilibrium calcite. In culture, however, a δ18O offset of −1‰ is observed at temperatures <17°C, which falls below the natural temperature range of this species. Culture analyses also reveal a relationship between temperature and carbon isotope composition of calcite. The mechanisms behind this relationship remain to be explored, but their identification may provide a better understanding of carbon isotope systematics from both biogeochemical and geological perspectives. Comparison of the oxygen isotope composition of T. heimii shells with that of shallower dwelling organisms, such as the coccolithophores, represents a valuable proxy for determining temperature gradients within the photic zone and may enable reconstruction of the evolution of the depth of the thermocline.
Flexible and Stretchable Lithium‐Ion Batteries and Supercapacitors Based on Electrically Conducting Carbon Nanotube Fiber Springs
Authors: Zhang Ye , Bai Wenyu , Cheng Xunliang , Ren Jing , Weng Wei , Chen Peining , Fang Xin , Zhang Zhitao , Peng Huisheng 
Published: October 2014

AbstractThe construction of lightweight, flexible and stretchable power systems for modern electronic devices without using elastic polymer substrates is critical but remains challenging. We have developed a new and general strategy to produce both freestanding, stretchable, and flexible supercapacitors and lithium‐ion batteries with remarkable electrochemical properties by designing novel carbon nanotube fiber springs as electrodes. These springlike electrodes can be stretched by over 300 %. In addition, the supercapacitors and lithium‐ion batteries have a flexible fiber shape that enables promising applications in electronic textiles.
The chlorination and chlorine resistance modification of composite polyamide membrane
Authors: Li Hao , Yu Ping , Li Haigang , Luo Yunbai 
Published: October 2014

ABSTRACTMembrane‐based separation technology is one of the most active separation technologies being employed in water treatment. Polyamides (PA) are widely used membrane materials because they exhibit excellent performance, such as high flux with high salt rejection, and enhanced stability against wide range of pH and temperature. Unfortunately, PA membranes exhibit extremely poor resistance to chlorine leading to increased operation costs and decreased membrane lifetime. In this study, we find new ways for prolonging membrane lifetime and reducing the operating costs by investigating the chlorination and modification of PA membranes. Varying concentrations of hypochlorite were used to chlorinate a commercial reverse osmosis membrane (BW‐30, DOW). The results showed that short‐time exposure to high concentrations of hypochlorite could cause more serious problems to membranes than long‐time exposure to low concentrations under the similar total exposure. The performance of the chlorinated membranes was recovered to some extent after treatment with NaOH solution (pH 10), indicating that the alkali treatment could initiate the reversible regeneration of chlorinated membranes. Furthermore, an industrial grade epoxy resin was used to modify the membranes to enhance the chlorine resistance via the reaction between the amide nitrogen and epoxy bond. The successful modifications were confirmed by attenuated total reflectance Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, scanning electron microscopy, and atomic force microscopy. Moreover, the chlorination tests showed that the modifications performed in these experiments enhanced the chlorine resistance of the membranes, especially for the membranes exposed to low concentration of chlorine. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41584.
Synthesis of two D‐π‐A polymers π‐bridged by different blocks and investigation of their photovoltaic property
Authors: Qin Ruiping , Jiang Yurong , Zhang Kaixuan , Zhang Haoxing , Zhang Qunying , Li Meng , Ma Heng 
Published: October 2014

ABSTRACTThe synthesis, characterization, photophysical and photovoltaic properties of two 5,6‐bis(octyloxy)benzo[c][1,2,5]thiadiazole‐containing wide‐band‐gap donor and acceptor D‐π‐A alternating conjugated polymers (HSD‐a and HSD‐b) have been reported. These two polymers absorb in the range of 300–700 nm with a band gap of about 1.88 and 1.97 eV. The HOMO energy levels were −5.44 eV for HSD‐a and −5.63 eV for HSD‐b. Polymer solar cells with HSD‐b :PC71BM as the active layer demonstrated a power conversion efficiency (PCE) of 2.59% with a high Voc of 0.93 V, a Jsc of 7.3 mA/cm2, and a comparable fill factor (FF) of 0.38 under simulated solar illumination of AM 1.5G (100 mW/cm2) without annealing. In addition, HSD‐a :PC71BM blend‐based solar cells exhibit a PCE of 2.15% with a comparable Voc of 0.64 V, Jsc of 8.75 mA/cm−2, and FF of 0.40. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41587.
Facet‐Dependent Photocatalytic Activity and Facet‐Selective Etching of Silver(I) Oxide Crystals with Controlled Morphology
Authors: Harn Yeu‐Wei , Yang Tung‐Han , Tang Tsung‐Yeh , Chen Miao‐Chun , Wu Jenn‐Ming 
Published: October 2014

AbstractThe shape of Ag2O crystals that evolve from edge and corner‐truncated cubes into rhombicuboctahedrons, then to hexapods can be conducted precisely by simply controlling the amount of AgNO3, NH4NO3 and NaOH precursors. The edge and corner‐truncated cube crystals possess the highest photocatalytic activity, followed by the rhombicuboctahedrons, then the hexapods. The photocatalytic activity of the Ag2O crystals depends greatly on the type of the exposed facets. The {1 0 0} facets exhibit the highest photocatalytic activity in methyl orange solution under full‐spectrum light irradiation, followed by the {1 1 0} facets, then the {1 1 1} facets. The {1 0 0} facets are also demonstrated to show intense susceptibility toward etching by NH3.
Palladium‐Catalyzed Carbonylative Reactions of 1‐Bromo‐2‐fluorobenzenes with Various Nucleophiles: Effective Combination of Carbonylation and Nucleophilic Substitution
Authors: Chen Jianbin , Natte Kishore , Neumann Helfried , Wu Xiao‐Feng 
Published: October 2014

AbstractA systematic study on the carbonylative transformation of 1‐bromo‐2‐fluorobenzenes with various nucleophiles has been performed. Different types of double nucleophiles, such as NN, NC, OC, and NS, can be effectively applied as coupling partners. The corresponding six‐membered heterocycles were isolated in moderate to good yields.
ChemInform Abstract: On Sr1‐xNaxSiO3—0.5x New Superior Fast Ion Conductors.
Authors: Evans Ivana Radosavljevic , Evans John S. O. , Davies Heather G. , Haworth Abby R. , Tate Matthew L. 
Published: October 2014

AbstractSr1‐xNaxSiO3‐0.5x (x = 0.1, 0.2, 0.3, 0.4) is prepared by solid state reaction of stoichiometric mixtures of SrCO3, Na2CO3, and silica powder (air, 1050 °C, 24‐96 h).
ChemInform Abstract: pH‐Controlled and Sulfite Anion‐Directed Assembly of a Family of Cerium(III)‐Containing Polyoxotungstates Clusters.
Authors: Chen Wei‐Chao , Wang Xin‐Long , Jiao Yan‐Qing , Huang Peng , Zhou En‐Long , Su Zhong‐Min , Shao Kui‐Zhan 
Published: October 2014

AbstractThe cerium(III)‐containing polyoxotungstates (III)—(VII) are characterized by single crystal XRD, IR spectroscopy, XPS, ESI‐MS, and electrochemical measurements.
ChemInform Abstract: Beyond Benzoin Condensation: Trimerization of Aldehydes via Metal‐Free Aerobic Oxidative Esterification of Aldehydes with Benzoin Products in the Presence of Cyanide.
Authors: Kim Yoo‐Jin , Kim Na Yeun , Cheon Cheol‐Hong 
Published: October 2014

AbstractBenzaldehydes trimerize in the presence of excess sodium cyanide.
ChemInform Abstract: Solar Photo‐Thermochemical Syntheses of 4‐Bromo‐2,5‐substituted Oxazoles from N‐Arylethylamides.
Authors: Dinda Milan , Samanta Supravat , Eringathodi Suresh , Ghosh Pushpito K. 
Published: October 2014

AbstractThe direct synthesis of 4‐bromo‐2,5‐substituted oxazoles and thiazoles is reported.
ChemInform Abstract: Catalyst‐Free Chemoselective Reduction of the Carbon—Carbon Double Bond in Conjugated Alkenes with Hantzsch Esters in Water.
Authors: He Qi , Xu Zhihong , Jiang Dehong , Ai Wensi , Shi Ronghua , Qian Shan , Wang Zhouyu 
Published: October 2014

AbstractA simple catalyst‐free protocol for the reduction of activated C=C double bonds to single bonds using Hantzsch esters as hydrogen source is presented.
ChemInform Abstract: Ruthenium Catalyzed C—H Bond Borylation.
Authors: Fernandez‐Salas Jose A. , Manzini Simone , Piola Lorenzo , Slawin Alexandra M. Z. , Nolan Steven P. 
Published: October 2014

AbstractThe Ru‐catalyzed regioselective ortho‐borylation of 2‐arylpyridines (I) leads to desired borylated adducts (III) in good yields.
ChemInform Abstract: Oxazoline Derivatives Tagged with Tosylated Amino Acids as Recyclable Organocatalysts for Enantioselective Allylation of Aldehydes.
Authors: Ghosh Debashis , Sadhukhan Arghya , Maity Nabin Ch. , Abdi Sayed H. R. , Khan Noor‐ul H. , Kureshy Rukhsana I. , Bajaj Hari C. 
Published: October 2014

AbstractSeveral chiral oxazoline‐based organocatalysts are prepared and applied in the asymmetric allylation reaction of aldehydes with allyltrichlorosilane whereas, best results are achieved using OXA as catalyst shown here.
ChemInform Abstract: Catalytic Asymmetric Peroxidation of α,β‐Unsaturated Nitroalkenes by a Bifunctional Organic Catalyst.
Authors: Lu Xiaojie , Deng Li 
Published: October 2014

AbstractThe first catalytic highly enantioselective peroxidation of nitroalkenes using a bifunctional cinchona sulfonamide as the catalyst is presented.
ChemInform Abstract: Light‐Induced Ruthenium‐Catalyzed Nitrene Transfer Reactions: A Photochemical Approach Towards N‐Acyl Sulfimides and Sulfoximines.
Authors: Bizet Vincent , Buglioni Laura , Bolm Carsten 
Published: October 2014

AbstractDioxazoles (I) decarboxylate under photochemical conditions to form N‐acyl nitrenes, which react with sulfides and sulfoxides to the corresponding sulfimides and sulfoximines under mild conditions.
ChemInform Abstract: Organocatalytic Domino Reactions: Synthesis of Densely Functionalized Cyclohexene Derivatives.
Authors: Bi Bo , Ding Yuyang , Lou Qinxin , Hu Wenhui , Chan Albert S. C. , Song Hongrui , Zhao Junling 
Published: October 2014

AbstractThe domino reaction of hexanal derivative (I) with α,β‐unsaturated aldehydes proceeds in the presence of a chiral diphenylsilylprolinol catalyst under mild conditions to give cyclohexene derivatives in good yields and with high enantioselectivities.
ChemInform Abstract: Palladium‐Catalyzed Direct Intramolecular Double α‐C—H Arylation of 1,5‐Diketone: A Strategy for Synthesis of Troeger′s Base Analogues.
Authors: Ju Jia , Zhang Lei , Hua Ruimao 
Published: October 2014

AbstractThe one‐pot synthesis of the title species (III) involves Michael addition of ketones (I) and (II) followed by intramolecular double α‐C‐H arylation of the 1,5‐diketone intermediates.
ChemInform Abstract: Visible‐Light‐Induced Formal [3 + 2] Cycloaddition for Pyrrole Synthesis under Metal‐Free Conditions.
Authors: Xuan Jun , Xia Xu‐Dong , Zeng Ting‐Ting , Feng Zhu‐Jia , Chen Jia‐Rong , Lu Liang‐Qiu , Xiao Wen‐Jing 
Published: October 2014

AbstractThe title synthesis provides an efficient access to highly functionalized pyrroles in good yields in the presence of organic dye photocatalyst.
ChemInform Abstract: An Environmentally Benign, Mild, and Catalyst‐Free Reaction of Quinones with Heterocyclic Ketene Aminals in Ethanol: Site‐Selective Synthesis of Rarely Fused [1,2‐a]Indolone Derivatives via an Unexpected anti‐Nenitzescu Strategy.
Authors: Zhou Bei , Liu Zhi‐Cheng , Qu Wen‐Wen , Yang Rui , Lin Xin‐Rong , Yan Sheng‐Jiao , Lin Jun 
Published: October 2014

AbstractAn environmentally benign method for the selective preparation of fused indolone derivatives via anti‐Nenitzescu strategy is developed.
ChemInform Abstract: Copper‐Catalyzed Oxoazidation and Alkoxyazidation of Indoles.
Authors: Yin Hang , Wang Teng , Jiao Ning 
Published: October 2014

AbstractA novel Cu‐catalyzed reaction of 3‐alkylated indoles with azidoiodinane and reactive alcoholic solvent is developed to produce indolenines (III) in good yields.
ChemInform Abstract: Cellulose—Sulfonic Acid: An Efficient, Recyclable, and Biodegradable Solid Acid Catalyst for the Synthesis of 3‐Aminoalkylindoles
Authors: Satyanarayana S. , Kumar K. Praveen , Reddy P. Lakshmi , Narender R. , Narasimhulu G. , Reddy B. V. Subba 
Published: October 2014

Abstractvia three‐component coupling of indoles, aromatic aldehydes and N‐alkylanilines (14 examples)
ChemInform Abstract: Synthesis of Benzo[a]carbazoles and Indolo[2,3‐a]carbazoles via Photoinduced Carbene‐Mediated C—H Insertion Reaction.
Authors: Yang Jidong , Zhang Qingzhao , Zhang Wei , Yu Wei 
Published: October 2014

AbstractA simple and efficient photochemical method is developed for the intramolecular cyclization of α‐diazoesters and nitriles to form benzocarbazoles and indolocarbazoles.
ChemInform Abstract: Pyrrolidine and Iodine Catalyzed Domino Aldol‐Michael‐Dehydrogenative Synthesis of Flavones.
Authors: Naik Mayuri M. , Tilve Santosh G. , Kamat Vijayendra P. 
Published: October 2014

AbstractHydroxyacetophenones react with aromatic aldehydes in the presence of pyrrolidine as base and iodine as an oxidant in DMSO to form various substituted flavones.