bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intrinsic ultracontractivity via capacitary width
Authors: Aikawa Hiroaki 
Published: October 2015

The semigroup associated with the Dirichlet heat kernel is said to be intrinsic ultracontractive if
(i) the Dirichlet realization of the associated self adjoint operator has the first positive eigenvalue with positive L2 eigenfunction;
(ii) the heat kernel is bounded above and below by the product of the eigenfunctions with positive multiplicative constants depending on time.
We give an upper and lower estimate of the first eigenvalue in terms of capacitary width, which yields a sharp sufficient condition for (i). Our parabolic argument also yields an exponential decay property of a certain caloric measure. Then, the caloric measure is controlled by the elliptic Green function with the aid of a parabolic box argument. This is a crucial step for (ii). We give a sharp sufficient integral condition for intrinsic ultracontractivity in terms of capacitary width. A similar integral condition for the boundary Harnack principle is also obtained. Under geometric specifications, these integral conditions generalize known results and give more precise conditions. Sharpness is examined by an infinite funnel, for which we obtain a complete characterization of intrinsic ultracontractivity. Our method is purely analytic and elementary; it enables us to dispense with logarithmic Sobolev inequalities.
Two different approaches to the affective profiles model: median splits (variable-oriented) and cluster analysis (person-oriented)
Authors: Garcia Danilo , MacDonald Shane , Archer Trevor 
Published: October 2015

Background.The notion of the affective system as being composed of two dimensions led Archer and colleagues to the development of the affective profiles model. The model consists of four different profiles based on combinations of individuals’ experience of high/low positive and negative affect: self-fulfilling, low affective, high affective, and self-destructive. During the past 10 years, an increasing number of studies have used this person-centered model as the backdrop for the investigation of between and within individual differences in ill-being and well-being. The most common approach to this profiling is by dividing individuals’ scores of self-reported affect using the median of the population as reference for high/low splits. However, scores just-above and just-below the median might become high and low by arbitrariness, not by reality. Thus, it is plausible to criticize the validity of this variable-oriented approach. Our aim was to compare the median splits approach with a person-oriented approach, namely, cluster analysis.Method.The participants (N= 2, 225) were recruited through Amazons’ Mechanical Turk and asked to self-report affect using the Positive Affect Negative Affect Schedule. We compared the profiles’homogeneityandSilhouette coefficientsto discern differences in homogeneity and heterogeneity between approaches. We also conducted exact cell-wise analyses matching the profiles from both approaches and matching profiles and gender to investigate profiling agreement with respect to affectivity levels and affectivity and gender. All analyses were conducted using the ROPstat software.Results.The cluster approach (weighted average of clusterhomogeneity coefficients= 0.62,Silhouette coefficients= 0.68) generated profiles with greater homogeneity and more distinctive from each other compared to the median splits approach (weighted average of clusterhomogeneity coefficients= 0.75,Silhouette coefficients= 0.59). Most of the participants (n= 1,736, 78.0%) were allocated to the same profile (Rand Index= .83), however, 489 (21.98%) were allocated to different profiles depending on the approach. Both approaches allocated females and males similarly in three of the four profiles. Only the cluster analysis approach classified men significantly more often than chance to a self-fulfilling profile (type) and females less often than chance to this very same profile (antitype).Conclusions.Although the question whether one approach is more appropriate than the other is still without answer, the cluster method allocated individuals to profiles that are more in accordance with the conceptual basis of the model and also to expected gender differences. More importantly, regardless of the approach, our findings suggest that the model mirrors a complex and dynamic adaptive system.
Sensitivity of dispersion model forecasts of volcanic ash clouds to the physical characteristics of the particles
Authors: Beckett F. M. , Witham C. S. , Hort M. C. , Stevenson J. A. , Bonadonna C. , Millington S. C. 
Published: October 2015

AbstractThis study examines the sensitivity of atmospheric dispersion model forecasts of volcanic ash clouds to the physical characteristics assigned to the particles. We show that the particle size distribution (PSD) used to initialise a dispersion model has a significant impact on the forecast of the mass loading of the ash particles in the atmosphere. This is because the modeled fall velocity of the particles is sensitive to the particle diameter. Forecasts of the long‐range transport of the ash cloud consider particles with diameters between 0.1 μm and 100 μm. The fall velocity of particles with diameter 100 μm is over 5 orders of magnitude greater than a particle with diameter 0.1 μm, and 30 μm particles fall 88% slower and travel up to 5× further than a 100 μm particle. Identifying the PSD of the ash cloud at the source, which is required to initialise a model, is difficult. Further, aggregation processes are currently not explicitly modeled in operational dispersion models due to the high computational costs associated with aggregation schemes. We show that using a modified total grain size distribution (TGSD) that effectively accounts for aggregation processes improves the modeled PSD of the ash cloud and deposits from the eruption of Eyjafjallajökull in 2010. Knowledge of the TGSD of an eruption is therefore critical for reducing uncertainty in quantitative forecasts of ash cloud dispersion. The density and shape assigned to the model particles have a lesser but still significant impact on the calculated fall velocity. Accounting for the density distribution and sphericity of ash from the eruption of Eyjafjallajökull in 2010, modeled particles can travel up to 84% further than particles with default particle characteristics that assume the particles are spherical and have a fixed density.
The impact of vertical shear on the sensitivity of tropical cyclogenesis to environmental rotation and thermodynamic state
Authors: Zhou Wenyu 
Published: October 2015

AbstractThe impact of vertical wind shear on the sensitivity of tropical cyclogenesis to environmental rotation and thermodynamic state is investigated through idealized cloud‐resolving simulations of the intensification of an incipient vortex. With vertical shear, tropical cyclones intensify faster with a higher Coriolis parameter, f, irrespective of the environmental thermodynamic state. The vertical shear develops a vertically tilted vortex, which undergoes a precession process with the midlevel vortices rotating cyclonically around the surface center. With a higher f, the midlevel vortices are able to rotate continuously against the vertical shear, leading to the realignment of the tilted vortex and rapid intensification. With a lower f, the rotation is too slow such that the midlevel vortices are advected away from the surface center and the intensification is suppressed. The parameter, χb, measuring the effect from the low‐entropy downdraft air on the boundary layer entropy, is found to be a good indicator of the environmental thermodynamic favorability for tropical cyclogenesis in vertical shear. Without vertical shear, tropical cyclones are found to intensify faster with a lower f by previous studies. We show this dependency on f is sensitive to the environmental thermodynamic state. The thermodynamical favorability for convection can be measured by χm, which estimates the time it takes for surface fluxes to moisten the midtroposphere. A smaller χm not only leads to a faster intensification due to a shorter period for moist preconditioning of the inner region but also neutralizes the faster intensification with a lower f due to enhanced peripheral convection.
N‐Imidazolylation of Sulfoximines from N‐Cyano Sulfoximines, 1‐Alkynes, and N‐Sulfonyl Azides
Authors: Kim Sanghyuck , Kim Ji Eun , Lee Jinsub , Lee Phil Ho 
Published: October 2015

AbstractThe rhodium‐catalyzed N‐imidazolylation of N‐sulfonyl‐1,2,3‐triazoles with a variety of N‐cyano sulfoximines has been developed for the synthesis of N‐imidazolyl sulfoximines via elimination of molecular nitrogen. Copper‐catalyzed [3+2] cycloaddition followed by rhodium‐catalyzed N‐imidazolylation from 1‐alkynes, N‐sulfonyl azides, and N‐cyano sulfoximines is also demonstrated for the synthesis of N‐imidazolyl sulfoximines in a one‐pot procedure.magnified image
An Electrically Driven and Readable Molecular Monolayer Switch Based on a Solid Electrolyte
Authors: Marchante Elena , Crivillers Núria , Buhl Moritz , Veciana Jaume , Mas‐Torrent Marta 
Published: October 2015

AbstractThe potential application of molecular switches as active elements in information storage has been demonstrated through numerous works. Importantly, such switching capabilities have also been reported for self‐assembled monolayers (SAMs). SAMs of electroactive molecules have recently been exploited as electrochemical switches. Typically, the state of these switches could be read out through their optical and/or magnetic response. These output reading processes are difficult to integrate into devices, and furthermore, there is a need to use liquid environments for switching the redox‐active molecular systems. In this work, both of these challenges were overcome by using an ionic gel as the electrolyte medium, which led to an unprecedented solid‐state device based on a single molecular layer. Moreover, electrochemical impedance has been successfully exploited as the output of the system.
Regio‐ and Stereospecific 1,3‐Allyl Group Transfer Triggered by a Copper‐Catalyzed Borylation/ortho‐Cyanation Cascade
Authors: Yang Yang 
Published: October 2015

AbstractA copper‐catalyzed borylation/ortho‐cyanation/allyl group transfer cascade was developed. Initiated by an unconventional copper‐catalyzed electrophilic dearomatization, this process features regio‐ and stereospecific 1,3‐transposition of the allyl fragment enabled by an aromatization‐driven Cope rearrangement. This method provides an effective means for the construction of adjacent tertiary and quaternary stereocenters with excellent diastereocontrol.
Tailoring of Electronic Structure and Thermoelectric Properties of a Topological Crystalline Insulator by Chemical Doping
Authors: Roychowdhury Subhajit , Shenoy U. Sandhya , Waghmare Umesh V. , Biswas Kanishka 
Published: October 2015

AbstractTopological crystalline insulators (TCIs) are a new quantum state of matter in which linearly dispersed metallic surface states are protected by crystal mirror symmetry. Owing to its vanishingly small bulk band gap, a TCI like Pb0.6Sn0.4Te has poor thermoelectric properties. Breaking of crystal symmetry can widen the band gap of TCI. While breaking of mirror symmetry in a TCI has been mostly explored by various physical perturbation techniques, chemical doping, which may also alter the electronic structure of TCI by perturbing the local mirror symmetry, has not yet been explored. Herein, we demonstrate that Na doping in Pb0.6Sn0.4Te locally breaks the crystal symmetry and opens up a bulk electronic band gap, which is confirmed by direct electronic absorption spectroscopy and electronic structure calculations. Na doping in Pb0.6Sn0.4Te increases p‐type carrier concentration and suppresses the bipolar conduction (by widening the band gap), which collectively gives rise to a promising zT of 1 at 856 K for Pb0.58Sn0.40Na0.02Te. Breaking of crystal symmetry by chemical doping widens the bulk band gap in TCI, which uncovers a route to improve TCI for thermoelectric applications.
Conceptual process design and economics for the production of high‐octane gasoline blendstock via indirect liquefaction of biomass through methanol/dimethyl ether intermediates
Authors: Tan Eric CD , Talmadge Michael , Dutta Abhijit , Hensley Jesse , Snowden‐Swan Lesley J. , Humbird David , Schaidle Joshua , Biddy Mary 
Published: October 2015

AbstractThis work describes in detail one potential conversion process for the production of high‐octane gasoline blendstock via indirect liquefaction of biomass. The processing steps of this pathway include the conversion of biomass to synthesis gas via indirect gasification, gas clean‐up via reforming of tars and other hydrocarbons, catalytic conversion of syngas to methanol, methanol dehydration to dimethyl ether (DME), and the homologation of DME over a zeolite catalyst to high‐octane gasoline‐range hydrocarbon products. The current process configuration has similarities to conventional methanol‐to‐gasoline (MTG) technologies, but there are key distinctions, specifically regarding the product slate, catalysts, and reactor conditions. A techno‐economic analysis is performed to investigate the production of high‐octane gasoline blendstock. The design features a processing daily capacity of 2000 tonnes (2205 short tons) of dry biomass. The process yields 271 liters of liquid fuel per dry tonne of biomass (65 gal/dry ton), for an annual fuel production rate of 178 million liters (47 MM gal) at 90% on‐stream time. The estimated total capital investment for an nth‐plant is $438 million. The resulting minimum fuel selling price (MFSP) is $0.86 per liter or $3.25 per gallon in 2011 US dollars. A rigorous sensitivity analysis captures uncertainties in costs and plant performance. Sustainability metrics for the conversion process are quantified and assessed. The potential premium value of the high‐octane gasoline blendstock is examined and found to be at least as competitive as fossil‐derived blendstocks. A simple blending strategy is proposed to demonstrate the potential for blending the biomass‐derived blendstock with petroleum‐derived intermediates. Published 2015. This article is a U.S. Government work and is in the public domain in the USA. Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley & Sons Ltd.
Core Halogenation as a Construction Principle in Tuning the Material Properties of Tetraazaperopyrenes
Authors: Hahn Lena , Maaß Friedrich , Bleith Tim , Zschieschang Ute , Wadepohl Hubert , Klauk Hagen , Tegeder Petra , Gade Lutz H. 
Published: October 2015

AbstractA detailed study on the effects of core halogenation of tetraazaperopyrene (TAPP) derivatives is presented. Its impact on the solid structure, as well as the photophysical and electrochemical properties, has been probed by the means of X‐ray crystallography, UV/Vis and fluorescence spectroscopy, high‐resolution electron energy loss spectroscopy (HREELS), cyclic voltammetry (CV), and DFT modeling. The aim was to assess the potential of this approach as a construction principle for organic electron‐conducting materials of the type studied in this work. Although halogenation leads to a stabilization of the LUMOs compared to the unsubstituted parent compound, the nature of the halide barely affects the LUMO energy while strongly influencing the HOMO energies. In terms of band‐gap engineering, it was demonstrated that the HOMO–LUMO gap is decreased by substitution of the TAPP core with halides, the effect being found to be most pronounced for the iodinated derivative. The performance of the recently reported core‐fluorinated and core‐iodinated TAPP derivatives in organic thin‐film transistors (TFTs) was investigated on both a glass substrate, as well as on a flexible plastic substrate (PEN). Field‐effect mobilities of up to 0.17 cm2 Vs−1 and on/off current ratio of >106 were established.
Visible‐Light‐Induced Direct Photocatalytic Carboxylation of Indoles with CBr4/MeOH
Authors: Yang Qing‐Qing , Marchini Marianna , Xiao Wen‐Jing , Ceroni Paola , Bandini Marco 
Published: October 2015

AbstractPhotocatalysis enables the cascade reactions of indoles and CBr4 in MeOH through a C(sp2)H functionalization/methanolysis sequence. The title reaction provides an efficient access to indole 2‐ and 3‐carboxylates in a single operation (no preinstallation of protecting as well as directing groups was required) with good yields under mild reaction conditions.
Oxidative Coupling of Terminal Alkynes with Aldehydes Leading to Alkynyl Ketones by Using Indium(III) Bromide
Authors: Ogiwara Yohei , Kubota Masahito , Kurogi Kotaro , Konakahara Takeo , Sakai Norio 
Published: October 2015

AbstractAn indium(III)‐promoted direct acylation of terminal alkynes using aldehydes leading to ynones was developed. In contrast to the previous addition reactions of alkynes to aldehydes, which provide propargylic alcohols, the oxidative coupling proceeded exclusively to afford alkynyl ketones. The products were likely generated through an Oppenauer oxidation of the indium propargylic alkoxide species by excess amounts of aldehydes.
Rheological behaviour of oil and water emulsions and their flow characterization in horizontal pipes
Authors: Zhang Jian , Xu Jing‐Yu 
Published: October 2015

AbstractIn this work, the rheological behaviour of oil and water emulsions and their flow characterization were studied using a Haake RS6000 rheometer and a lab scale flow loop. The rheological properties of the synthetic emulsions were investigated at oil volume fractions from 0.1–1.0 L/L and shear rates from 0.001–1000 s−1 at a system temperature of 20 °C. The emulsions flow, formed by the SMV static mixer installed before the test section, was observed in the 2‐m long horizontal pipes with 25 and 50 mm inner diameters at different mixture flow rates from 0.01–7.00 m3/h. A comparison between rheological measurements and laminar flow data shows that the values of the Sauter mean droplet diameters formed by the SMV static mixer are approximately one order of magnitude bigger than those measured by the rheometer. For oil‐in‐water emulsions with low oil content, the stress‐strain relationships obtained in the rheometer are more suitable for predicting the transport characteristics of the emulsions with a large pipe diameter than those with a small pipe diameter. In addition, the phase inversion points in the pipe flow are closer to those measured at high shear rates in the rheometer. Therefore, the apparent viscosity obtained by the rheology measurements at high shear rates could be introduced for accurate calculations of the mixture Reynolds number and the friction factor in emulsions flow.
From Solid Carbon Sources to Graphene
Authors: Liang Tao , Kong Yuhan , Chen Hongzheng , Xu Mingsheng 
Published: October 2015

AbstractChemical vapor deposition on metal substrates using gaseous hydrocarbon as carbon feedstock has proven to be a feasible way for synthesis of large‐area and uniform graphene films. Meanwhile, rearrangement of amorphous carbon species extracted from solid carbon sources into crystalline graphene not only offers an alternative route for graphene growth but also provides a powerful tool to excavate the underlying mechanisms of graphene formation. In this review, we discuss the processes of extracting carbon species from various solid carbon sources to form graphene. We summarize the typical steps of solid carbon sources to graphene transition and evaluate the resultant graphene film quality with regard to electrical performance. Unveiling the detailed solid carbon to graphene transition process paves the way for a reproducible production of graphene with controlled layer number, defect type and density, toward the final end of graphene's commercial utilizations with low cost.
Solution‐Processed Graphene Composite Films as Freestanding Platinum‐Free Counter Electrodes for Bendable Dye Sensitized Solar Cells
Authors: Zhou Qinqin , Chen Shan , Zhang Miao , Wang Liduo , Li Yingru , Shi Gaoquan 
Published: October 2015

AbstractSulfuric acid‐treated poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate)/less‐defective reduced graphene oxide (ST‐PEDOT:PSS/L‐rGO) composite films were prepared via a solution‐processing route and used as the counter electrodes of dye sensitized solar cells (DSSCs). These platinum (Pt)‐ and transparent conductive oxide (TCO)‐free counter electrodes exhibited strong catalytic activity and excellent flexibility, showing no obvious change in their sheet resistances after 10000 cycles of bending. The integrated quasi‐solid‐state DSSC device with a TiO2 nanotube/Ti mesh photoanode and a ST‐PEDOT:PSS/L‐rGO counter electrode exhibited an energy conversion efficiency (η) of about 1.8%. It also displayed an excellent mechanical stability and durability after bending for 1000 cycles at a small curvature radius of 10 mm. The high flexibility, low cost and efficient catalytic activity make ST‐PEDOT:PSS/L‐rGO composite films promising counter electrodes for flexible DSSCs.
Plant–plant interactions as a mechanism structuring plant diversity in a Mediterranean semi‐arid ecosystem
Authors: Arroyo Antonio I. , Pueyo Yolanda , Saiz Hugo , Alados Concepción L. 
Published: October 2015

AbstractPlant–plant interactions are among the fundamental processes that shape structure and functioning of arid and semi‐arid plant communities. Despite the large amount of studies that have assessed the relationship between plant–plant interactions (i.e., facilitation and competition) and diversity, often researchers forget a third kind of interaction, known as allelopathy. We examined the effect of plant–plant interactions of three dominant species: the perennial grass Lygeum spartum, the allelopathic dwarf shrub Artemisia herba‐alba, and the nurse shrub Salsola vermiculata, on plant diversity and species composition in a semi‐arid ecosystem in NE Spain. Specifically, we quantified the interaction outcome (IO) based on species co‐occurrence, we analyzed diversity by calculation of the individual species–area relationship (ISAR), and compositional changes by calculation of the Chao‐Jaccard similarity index. We found that S. vermiculata had more positive IO values than L. spartum, and A. herba‐alba had values between them. Lygeum spartum and A. herba‐alba acted as diversity repellers, whereas S. vermiculata acted as a diversity accumulator. As aridity increased, A. herba‐alba transitioned from diversity repeller to neutral and S. vermiculata transitioned from neutral to diversity accumulator, while L. spartum remained as diversity repeller. Artemisia herba‐alba had more perennial grass species in its local neighborhood than expected by the null model, suggesting some tolerance of this group to its “chemical neighbor”. Consequently, species that coexist with A. herba‐alba were very similar among different A. herba‐alba individuals. Our findings highlight the role of the nurse shrub S. vermiculata as ecosystem engineer, creating and maintaining patches of diversity, as well as the complex mechanism that an allelopathic plant may have on diversity and species assemblage. Further research is needed to determine the relative importance of allelopathy and competition in the overall interference of allelopathic plants.