bluuebunny/crossref_metadata_2025_split huggingface dataset:
Can increasing albedo of existing ship wakes reduce climate change?
Authors: Crook Julia A. , Jackson Lawrence S. , Forster Piers M. 
Published: January 2016

AbstractSolar radiation management schemes could potentially alleviate the impacts of global warming. One such scheme could be to brighten the surface of the ocean by increasing the albedo and areal extent of bubbles in the wakes of existing shipping. Here we show that ship wake bubble lifetimes would need to be extended from minutes to days, requiring the addition of surfactant, for ship wake area to be increased enough to have a significant forcing. We use a global climate model to simulate brightening the wakes of existing shipping by increasing wake albedo by 0.2 and increasing wake lifetime by ×1440. This yields a global mean radiative forcing of −0.9 ± 0.6 Wm−2 (−1.8 ± 0.9 Wm−2 in the Northern Hemisphere) and a 0.5°C reduction of global mean surface temperature with greater cooling over land and in the Northern Hemisphere, partially offsetting greenhouse gas warming. Tropical precipitation shifts southward but remains within current variability. The hemispheric forcing asymmetry of this scheme is due to the asymmetry in the distribution of existing shipping. If wake lifetime could reach ~3 months, the global mean radiative forcing could potentially reach −3 Wm−2. Increasing wake area through increasing bubble lifetime could result in a greater temperature reduction, but regional precipitation would likely deviate further from current climatology as suggested by results from our uniform ocean albedo simulation. Alternatively, additional ships specifically for the purpose of geoengineering could be used to produce a larger and more hemispherically symmetrical forcing.
Lithospheric flexure and gravity spreading of Olympus Mons volcano, Mars
Authors: Musiol S. , Holohan E. P. , Cailleau B. , Platz T. , Dumke A. , Walter T. R. , Williams D. A. , van Gasselt S. 
Published: January 2016

AbstractThe structural architecture of large volcanoes is governed substantially by gravity‐driven deformation that is manifest as distinct processes such as basement flexure or volcanic spreading. Temporal effects and the mutual interplay of these processes have been investigated only to a limited extent, and so we present novel numerical models of the time‐dependent deformation associated with them. The models simulate the combined effects of lithospheric flexure and volcanic spreading during growth increments of an elastoplastic volcanic cone. Different spreading scenarios are considered by a variable coupling decoupling behavior at the interface between volcano and basement. We apply our models to Olympus Mons on Mars, which is characterized by upper to middle flank terraces on the shield, is encircled by a basal scarp that has an average slope of 30° and is surrounded by distant deposits that resemble large‐scale slumping features on Earth. Our results are consistent with the interpretation that terraces on Olympus Mons' flanks form by thrust faulting that results from lithospheric flexure. The presence and expression of terraces depend on the coupling of volcano and basement, on the time of volcano growth relative to mantle relaxation, and on the cohesion of the edifice. The encircling scarp may be related to a very low friction detachment at the edifice base, which leads to a normal fault regime on the lowermost flanks. With time and volcano growth, predicted stress and faulting regimes migrate only slightly, indicating that the structural architecture of volcanoes is largely set in the very early stages of formation.
Landscape response to late Pleistocene climate change in NW Argentina: Sediment flux modulated by basin geometry and connectivity
Authors: Schildgen Taylor F. , Robinson Ruth A. J. , Savi Sara , Phillips William M. , Spencer Joel Q. G. , Bookhagen Bodo , Scherler Dirk , Tofelde Stefanie , Alonso Ricardo N. , Kubik Peter W. , Binnie Steven A. , Strecker Manfred R. 
Published: January 2016

AbstractFluvial fill terraces preserve sedimentary archives of landscape responses to climate change, typically over millennial timescales. In the Humahuaca Basin of NW Argentina (Eastern Cordillera, southern Central Andes), our 29 new optically stimulated luminescence ages of late Pleistocene fill terrace sediments demonstrate that the timing of past river aggradation occurred over different intervals on the western and eastern sides of the valley, despite their similar bedrock lithology, mean slopes, and precipitation. In the west, aggradation coincided with periods of increasing precipitation, while in the east, aggradation coincided with decreasing precipitation or more variable conditions. Erosion rates and grain size dependencies in our cosmogenic 10Be analyses of modern and fill terrace sediments reveal an increased importance of landsliding compared to today on the west side during aggradation, but of similar importance during aggradation on the east side. Differences in the timing of aggradation and the 10Be data likely result from differences in valley geometry, which causes sediment to be temporarily stored in perched basins on the east side. It appears as if periods of increasing precipitation triggered landslides throughout the region, which induced aggradation in the west, but blockage of the narrow bedrock gorges downstream from the perched basins in the east. As such, basin geometry and fluvial connectivity appear to strongly influence the timing of sediment movement through the system. For larger basins that integrate subbasins with differing geometries or degrees of connectivity (like Humahuaca), sedimentary responses to climate forcing are likely attenuated.
Modeling the interference environment in the HF band
Authors: Pederick L. H. , Cervera M. A. 
Published: January 2016

AbstractThe performance of systems using high frequency (HF) radio waves, such as over‐the‐horizon radars (OTHR), can be strongly affected by external interferers at great distances (thousands of kilometers) from the systems receiver. However, the propagation of interference has complex behavior and is known to vary with location, time, season, sunspot number, and radio frequency. Understanding how the level of interference varies with all of these factors is important for the design of new systems such as next generation OTHR. By combining databases of known transmitters, ray‐tracing propagation, and a model ionosphere, a model of the behavior of interference at HF has been developed.
The Longriqu fault zone, eastern Tibetan Plateau: Segmentation and Holocene behavior
Authors: Ansberque Claire , Bellier Olivier , Godard Vincent , Lasserre Cécile , Wang Mingming , Braucher Régis , Talon Brigitte , de Sigoyer Julia , Xu Xiwei , Bourlès Didier L. 
Published: January 2016

AbstractThe dextral Longriba fault system (LFS), ~300 km long and constituting of two fault zones, has recently been recognized as an important structure of the eastern Tibetan plateau (Sichuan province), as it accommodates a significant amount of the deformation induced by the ongoing Indo‐Asian collision. Although previous paleoseismological investigations highlighted its high seismogenic potential, no systematic quantification of the dextral displacements along the fault system has been undertaken so far. As such information is essential to appraise fault behavior, we propose here a first detailed analysis of the segmentation of the Longriqu fault, the northern fault zone of the LFS, and an offset inventory of morphological features along the fault, using high‐resolutionPleiadessatellite images. We identify six major segments forming a mature fault zone. Offsets inventory suggests a characteristic coseismic displacement of ~4 m. Two alluvial fans, with minimum ages of 6.7 and 13.2 ka, respectively displaced by 23 ± 7 m and 40 ± 5 m, give an estimate of the maximal horizontal slip rate on the Longriqu fault of 3.2 ± 1.1 mm yr−1. As a result, a minimum ~1340 year time interval between earthquakes is expected.
Experimental and Computational Analysis of the Solvent‐Dependent O2/Li+‐O2− Redox Couple: Standard Potentials, Coupling Strength, and Implications for Lithium–Oxygen Batteries
Authors: Kwabi David G. , Bryantsev Vyacheslav S. , Batcho Thomas P. , Itkis Daniil M. , Thompson Carl V. , Shao‐Horn Yang 
Published: January 2016

AbstractUnderstanding and controlling the kinetics of O2 reduction in the presence of Li+‐containing aprotic solvents, to either Li+‐O2− by one‐electron reduction or Li2O2 by two‐electron reduction, is instrumental to enhance the discharge voltage and capacity of aprotic Li‐O2 batteries. Standard potentials of O2/Li+‐O2− and O2/O2− were experimentally measured and computed using a mixed cluster‐continuum model of ion solvation. Increasing combined solvation of Li+ and O2− was found to lower the coupling of Li+‐O2− and the difference between O2/Li+‐O2− and O2/O2− potentials. The solvation energy of Li+ trended with donor number (DN), and varied greater than that of O2− ions, which correlated with acceptor number (AN), explaining a previously reported correlation between Li+‐O2− solubility and DN. These results highlight the importance of the interplay between ion–solvent and ion–ion interactions for manipulating the energetics of intermediate species produced in aprotic metal–oxygen batteries.
Durch Nichtedelmetallsalze ausgelöste Friedel‐Crafts‐artige intermolekulare C‐H‐Silylierung von elektronenreichen Arenen
Authors: Yin Qin , Klare Hendrik F. T. , Oestreich Martin 
Published: January 2016

AbstractEs wird über eine elektrophile aromatische Substitution (SEAr) mit einem katalytisch erzeugten Siliciumelektrophil berichtet. Bei Aktivierung mit NaBArF4 wirkt im Grunde jedes käufliche Nichtedelmetallsalz als Initiator/Katalysator. Die auf diese Weise gebildete Lewis‐Säure vermittelt dann die SEAr von elektronenreichen Arenen mit Hydrosilanen, nicht aber mit Halogensilanen. Diese neue C‐H‐Silylierung ist für FeCl2/NaBArF4 optimiert und erbringt gute Ausbeuten bei Katalysatorbeladungen von lediglich 0.5 Mol‐%. Die Vorgehensweise ist denkbar einfach und kommt typischen Friedel‐Crafts‐Reaktionsvorschriften nahe, bei denen keine zusätzliche Base zum Abfangen der freigesetzten Protonen vonnöten ist.
Chiral Phosphoric Acid Catalyzed Kinetic Resolution of Indolines Based on a Self‐Redox Reaction
Authors: Saito Kodai , Akiyama Takahiko 
Published: January 2016

AbstractA strategy for oxidative kinetic resolution of racemic indolines was developed, employing salicylaldehyde derivative as the pre‐resolving reagent and chiral phosphoric acid as the catalyst. The iminium intermediate, formed by the condensation reaction of an enantiomer of indoline with salicylaldehyde derivative, was hydrogenated by the same enantiomer of indoline to afford another enantiomer of indoline by a self‐redox mechanism. The oxidative kinetic resolution of 2‐aryl‐substituted indolines proceeded to give enantiomers in good yields with excellent enantioselectivities.
Porous Organic Polymer Films with Tunable Work Functions and Selective Hole and Electron Flows for Energy Conversions
Authors: Gu Cheng , Huang Ning , Chen Youchun , Zhang Huanhuan , Zhang Shitong , Li Fenghong , Ma Yuguang , Jiang Donglin 
Published: January 2016

AbstractOrganic optoelectronics are promising technologies for energy conversion. However, the electrode interlayer, a key material between active layers and conducting electrodes that controls the transport of charge carriers in and out of devices, is still a chemical challenge. Herein, we report a class of porous organic polymers with tunable work function as hole‐ and electron‐selective electrode interlayers. The network with organoborane and carbazole units exhibits extremely low work‐function‐selective electron flow; while upon ionic ligation and electro‐oxidation, the network significantly increases the work function and turns into hole conduction. We demonstrate their outstanding functions as anode and cathode interlayers in energy‐converting solar cells and light‐emitting diodes.
Überwindung von Phasentransportlimitierungen in der Umsetzung lipophiler Oleoverbindungen in wässrigen Medien – ein temperaturgesteuerter Ansatz
Authors: Gaide Tom , Dreimann Jens M. , Behr Arno , Vorholt Andreas J. 
Published: January 2016

AbstractIn dieser Forschungsarbeit wird ein neues Verfahrenskonzept zur Katalysatorabtrennung von Übergangsmetallkomplexen bei der Synthese mittelpolarer Produkte mit neu entwickelten wässrigen thermomorphen Mehrkomponenten‐Lösungsmittelsystemen vorgestellt. Ein Schwerpunkt der Prozessentwicklung liegt in der Nutzung von “grünen” Lösungsmitteln (1‐Butanol und Wasser) zur Hydroformylierung des biobasierten Substrats 10‐Undecensäuremethylester. Nach der erfolgreichen Entwicklung eines zweiphasigen Reaktionssystems im Labormaßstab wurde die Reaktion in eine kontinuierlich betriebene Anlage überführt, in der die Robustheit des neuen wässrigen Katalysatorrecyclingkonzepts demonstriert wird.
A General Strategy for the Nickel‐Catalyzed C−H Alkylation of Anilines
Authors: Ruan Zhixiong , Lackner Sebastian , Ackermann Lutz 
Published: January 2016

AbstractThe C−H alkylation of aniline derivatives with both primary and secondary alkyl halides was achieved with a versatile nickel catalyst of a vicinal diamine ligand. Step‐economic access to functionalized 2‐pyrimidyl anilines, key structural motifs in anticancer drugs, is thus provided. The C−H functionalization proceeded through facile C−H activation and SET‐type C−X bond cleavage with the assistance of a monodentate directing group, which could be removed in a traceless fashion.
Single‐Molecule Nanocatalysis Shows In Situ Deactivation of Pt/C Electrocatalysts during the Hydrogen‐Oxidation Reaction
Authors: Zhang Yuwei , Chen Tao , Alia Shaun , Pivovar Bryan S. , Xu Weilin 
Published: January 2016

AbstractBy coupling a Pt‐catalyzed fluorogenic reaction with the Pt‐electrocatalyzed hydrogen‐oxidation reaction (HOR), we combine single‐molecule fluorescence microscopy with traditional electrochemical methods to study the real‐time deactivation kinetics of a Pt/C electrocatalyst at single‐particle level during electrocatalytic hydrogen‐oxidation reaction. The decay of the catalytic performance of Pt/C could be mainly attributed to the electrocatalysis‐induced etching or dissolution of Pt nanoparticles. Spontaneous regeneration of activity and incubation period of the Pt electrocatalyst were also observed at single‐particle level. All these new insights are practically useful for the understanding and rational design of highly efficient electrocatalysts for application in fuel cells.
Reductive Cyclopropanations Catalyzed by Dinuclear Nickel Complexes
Authors: Zhou You‐Yun , Uyeda Christopher 
Published: January 2016

AbstractDinuclear Ni complexes supported by naphthyridine‐diimine (NDI) ligands catalyze the reductive cyclopropanation of alkenes with CH2Cl2 as the methylene source. The use of mild terminal reductants (Zn or Et2Zn) confers significant functional‐group tolerance, and the catalyst accommodates structurally and electronically diverse alkenes. Mononickel catalysts bearing related N chelates afford comparatively low cyclopropane yields (≤20 %). These results constitute an entry into catalytic carbene transformations from oxidized methylene precursors.
Enzyme Selectivity Fine‐Tuned through Dynamic Control of a Loop
Authors: Vögeli Beat , Bibow Stefan , Chi Celestine N. 
Published: January 2016

AbstractAllostery has been revealed as an essential property of all proteins. For enzymes, shifting of the structural equilibrium distribution at one site can have substantial impacts on protein dynamics and selectivity. Promising sites of remotely shifting such a distribution by changing the dynamics would be at flexible loops because relatively large changes may be achieved with minimal modification of the protein. A ligand‐selective change of binding affinity to the active site of cyclophilin is presented involving tuning of the dynamics of a highly flexible loop. Binding affinity is increased upon substitution of double Gly to Ala at the hinge regions of the loop. Quenching of the motional amplitudes of the loop slightly rearranges the active site. In particular, key residues for binding Phe60 and His126 adopt a more fixed orientation in the bound protein. Our system may serve as a model system for studying the effects of various time scales of loop motion on protein function tuned by mutations.
Dendrite‐Free Nanocrystalline Zinc Electrodeposition from an Ionic Liquid Containing Nickel Triflate for Rechargeable Zn‐Based Batteries
Authors: Liu Zhen , Cui Tong , Pulletikurthi Giridhar , Lahiri Abhishek , Carstens Timo , Olschewski Mark , Endres Frank 
Published: January 2016

AbstractMetallic zinc is a promising anode material for rechargeable Zn‐based batteries. However, the dendritic growth of zinc has prevented practical applications. Herein it is demonstrated that dendrite‐free zinc deposits with a nanocrystalline structure can be obtained by using nickel triflate as an additive in a zinc triflate containing ionic liquid. The formation of a thin layer of Zn–Ni alloy (η‐ and γ‐phases) on the surface and in the initial stages of deposition along with the formation of an interfacial layer on the electrode strongly affect the nucleation and growth of zinc. A well‐defined and uniform nanocrystalline zinc deposit with particle sizes of about 25 nm was obtained in the presence of NiII. Further, it is shown that the nanocrystalline Zn exhibits a high cycling stability even after 50 deposition/stripping cycles. This strategy of introducing an inorganic metal salt in ionic liquid electrolytes can be considered as an efficient way to obtain dendrite‐free zinc.
A Bis(Diphosphanyl N‐Heterocyclic Carbene) Gold Complex: A Synthon for Luminescent Rigid AuAg2 Arrays and Au5 and Cu6 Double Arrays
Authors: Ai Pengfei , Mauro Matteo , De Cola Luisa , Danopoulos Andreas A. , Braunstein Pierre 
Published: January 2016

AbstractA mononuclear bis(NHC)/AuI (NHC=N‐heterocyclic carbene) cationic complex with a rigid bis(phosphane)‐functionalized NHC ligand (PCNHCP) was used to construct linear Au3 and Ag2Au arrays, a Au5 cluster with two intersecting crosslike Au3 arrays, and an unprecedented Cu6 complex with two parallel Cu3 arrays. The impact of metallophilic interactions on photoluminescence was studied experimentally.
Overcoming Phase‐Transfer Limitations in the Conversion of Lipophilic Oleo Compounds in Aqueous Media—A Thermomorphic Approach
Authors: Gaide Tom , Dreimann Jens M. , Behr Arno , Vorholt Andreas J. 
Published: January 2016

AbstractA new process concept has been developed for recycling transition‐metal catalysts in the synthesis of moderately polar products via aqueous thermomorphic multicomponent solvent systems. This work focuses on the use of “green” solvents (1‐butanol and water) in the hydroformylation of the bio‐based substrate methyl 10‐undecenoate. Following the successful development of a biphasic reaction system on the laboratory scale, the reaction was transferred to a continuously operated miniplant to demonstrate the robustness of this innovative recycling concept for homogenous catalysts.
The Largest Metalloid Group 14 Cluster, Ge18[Si(SiMe3)3]6: An Intermediate on the Way to Elemental Germanium
Authors: Kysliak Oleksandr , Schrenk Claudio , Schnepf Andreas 
Published: January 2016

AbstractThe oxidation of [Ge9(Hyp)3]− (Hyp=Si(SiMe3)3) with an FeII salt leads to Ge18(Hyp)6 (1), the largest Group 14 metalloid cluster that has been structurally characterized to date. The arrangement of the 18 germanium atoms in 1 shows similarities to that found in the solid‐state structure Ge(cF136). Furthermore, 1 can be described as a macropolyhedral cluster of two Ge9 units. Quantum‐chemical calculations further hint at a strained arrangement so that 1 can be considered as a first trapped intermediate on the way from Ge9 units to elemental germanium with the clathrate‐II structure (Ge(cF136)).
Silver‐Mediated Intermolecular 1,2‐Alkylarylation of Styrenes with α‐Carbonyl Alkyl Bromides and Indoles
Authors: Ouyang Xuan‐Hui , Song Ren‐Jie , Hu Ming , Yang Yuan , Li Jin‐Heng 
Published: January 2016

AbstractA new iron‐facilitated silver‐mediated radical 1,2‐alkylarylation of styrenes with α‐carbonyl alkyl bromides and indoles is described, and two new C−C bonds were generated in a single step through a sequence of intermolecular C(sp3)−Br functionalization and C(sp2)−H functionalization across the alkenes. This method provides an efficient access to alkylated indoles with broad substrate scope and excellent selectivity.
Effects of plasticization and hydrostatic pressure on tensile properties ofPMMAunder compressed carbon dioxide and nitrogen
Authors: Taguchi Tomoaki , Saito Hiromu 
Published: January 2016

ABSTRACTWe investigated the stress−strain behavior of PMMA films under compressed CO2and N2. The elongation at break increased and the stress decreased with increasing CO2pressure at pressures above 3 MPa, indicating that the tensile property changed from brittle to ductile under compressed CO2. In contrast, the material property became more brittle under compressed CO2at pressures below 2 MPa and under compressed N2. By depressurizing the compressed gas and excluding the hydrostatic pressure, the property of the gas‐absorbed specimen changed from brittle to ductile. These results suggest that deformability by molecular orientation is enhanced by the plasticizing effect caused by a large amount of absorbed gas while it is suppressed by the effect of hydrostatic pressure caused by a small amount of absorbed gas. Conversely, the elastic modulus decreased under both compressed CO2and N2, but the decrease under CO2was much larger than that under N2, suggesting that distortion in the elastic region is dominated by the plasticization effect. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2016,133, 43431.