bluuebunny/crossref_metadata_2025_split huggingface dataset:
The CAMELS data set: catchment attributes and meteorology for large-sample studies
Authors: Addor Nans , Newman Andrew J. , Mizukami Naoki , Clark Martyn P. 
Published: October 2017

Abstract. We present a new data set of attributes for 671 catchments in the contiguous United States (CONUS) minimally impacted by human activities. This complements the daily time series of meteorological forcing and streamflow provided by Newman et al. (2015b). To produce this extension, we synthesized diverse and complementary data sets to describe six main classes of attributes at the catchment scale: topography, climate, streamflow, land cover, soil, and geology. The spatial variations among basins over the CONUS are discussed and compared using a series of maps. The large number of catchments, combined with the diversity of the attributes we extracted, makes this new data set well suited for large-sample studies and comparative hydrology. In comparison to the similar Model Parameter Estimation Experiment (MOPEX) data set, this data set relies on more recent data, it covers a wider range of attributes, and its catchments are more evenly distributed across the CONUS. This study also involves assessments of the limitations of the source data sets used to compute catchment attributes, as well as detailed descriptions of how the attributes were computed. The hydrometeorological time series provided by Newman et al. (2015b, https://doi.org/10.5065/D6MW2F4D) together with the catchment attributes introduced in this paper (https://doi.org/10.5065/D6G73C3Q) constitute the freely available CAMELS data set, which stands for Catchment Attributes and MEteorology for Large-sample Studies.
Network-based study of Lagrangian transport and mixing
Authors: Padberg-Gehle Kathrin , Schneide Christiane 
Published: October 2017

Abstract. Transport and mixing processes in fluid flows are crucially influenced by coherent structures and the characterization of these Lagrangian objects is a topic of intense current research. While established mathematical approaches such as variational methods or transfer-operator-based schemes require full knowledge of the flow field or at least high-resolution trajectory data, this information may not be available in applications. Recently, different computational methods have been proposed to identify coherent behavior in flows directly from Lagrangian trajectory data, that is, numerical or measured time series of particle positions in a fluid flow. In this context, spatio-temporal clustering algorithms have been proven to be very effective for the extraction of coherent sets from sparse and possibly incomplete trajectory data. Inspired by these recent approaches, we consider an unweighted, undirected network, where Lagrangian particle trajectories serve as network nodes. A link is established between two nodes if the respective trajectories come close to each other at least once in the course of time. Classical graph concepts are then employed to analyze the resulting network. In particular, local network measures such as the node degree, the average degree of neighboring nodes, and the clustering coefficient serve as indicators of highly mixing regions, whereas spectral graph partitioning schemes allow us to extract coherent sets. The proposed methodology is very fast to run and we demonstrate its applicability in two geophysical flows – the Bickley jet as well as the Antarctic stratospheric polar vortex.
El (no) lugar de la filosofía en la sociedad
Authors: Acosta Yamandú 
Published: October 2017

Since pre-socratic philosophers, Philosophy has been an activity that distinguishes itself from profit and power. It is located in a "non-piece" regarding the economic and politic competitions. Nevenheless, this does not lead philosophy to indifference toward reality. Moreover, it is a necessary condition to its critic to power.Realidad: Revista de Ciencias Sociales y Humanidades No. 118, 2008: 677-689
Effects of GnRHa treatment during vitellogenesis on the reproductive physiology of thermally challenged female Atlantic salmon (Salmo salar)
Authors: Anderson Kelli , Pankhurst Ned , King Harry , Elizur Abigail 
Published: October 2017

Tasmanian Atlantic salmon (S. salar) broodstock can experience temperatures above 20 °C, which impairs reproductive development and inhibits ovulation. The present study investigated the prolonged use of gonadotropin releasing hormone analogue (GnRHa) during vitellogenesis as a means of maintaining endocrine function and promoting egg quality at elevated temperature in maiden and repeat spawning S. salar. GnRHa-treatment during vitellogenesis did not compensate for the negative effects of thermal challenge on the timing of ovulation, egg size, egg fertility or embryo survival in any fish maintained at 22 °C relative to 14 °C. The lack of effectiveness was reflected by the endocrine data, as plasma follicle stimulating hormone and luteinising hormone levels were not different between treated and untreated groups at 22 °C. Furthermore, plasma testosterone and E2 levels were unchanged in GnRHa-treated fish at 22 °C, and plasma levels were generally lower in both groups maintained at 22 °C relative to 14 °C. Transcription of vitellogenin, and zona pellucida B and C was not enhanced in GnRHa-treated fish relative to untreated fish at 22 °C, presumably due to observed suppression of plasma E2. These results indicate that thermal impairment of reproduction is likely to occur on multiple levels, and is difficult to overcome via hormonal manipulation.
Influence of current climate, historical climate stability and topography on species richness and endemism in Mesoamerican geophyte plants
Authors: Sosa Victoria , Loera Israel 
Published: October 2017

BackgroundA number of biotic and abiotic factors have been proposed as drivers of geographic variation in species richness. As biotic elements, inter-specific interactions are the most widely recognized. Among abiotic factors, in particular for plants, climate and topographic variables as well as their historical variation have been correlated with species richness and endemism. In this study, we determine the extent to which the species richness and endemism of monocot geophyte species in Mesoamerica is predicted by current climate, historical climate stability and topography.MethodsUsing approximately 2,650 occurrence points representing 507 geophyte taxa, species richness (SR) and weighted endemism (WE) were estimated at a geographic scale using grids of 0.5 × 0.5 decimal degrees resolution using Mexico as the geographic extent. SR and WE were also estimated using species distributions inferred from ecological niche modeling for species with at least five spatially unique occurrence points. Current climate, current to Last Glacial Maximum temperature, precipitation stability and topographic features were used as predictor variables on multiple spatial regression analyses (i.e., spatial autoregressive models, SAR) using the estimates of SR and WE as response variables. The standardized coefficients of the predictor variables that were significant in the regression models were utilized to understand the observed patterns of species richness and endemism.ResultsOur estimates of SR and WE based on direct occurrence data and distribution modeling generally yielded similar results, though estimates based on ecological niche modeling indicated broader distribution areas for SR and WE than when species richness was directly estimated using georeferenced coordinates. The SR and WE of monocot geophytes were highest along the Trans-Mexican Volcanic Belt, in both cases with higher levels in the central area of this mountain chain. Richness and endemism were also elevated in the southern regions of the Sierra Madre Oriental and Occidental mountain ranges, and in the Tehuacán Valley. Some areas of the Sierra Madre del Sur and Sierra Madre Oriental had high levels of WE, though they are not the areas with the highest SR. The spatial regressions suggest that SR is mostly influenced by current climate, whereas endemism is mainly affected by topography and precipitation stability.ConclusionsBoth methods (direct occurrence data and ecological niche modeling) used to estimate SR and WE in this study yielded similar results and detected a key area that should be considered in plant conservation strategies: the central region of the Trans-Mexican Volcanic Belt. Our results also corroborated that species richness is more closely correlated with current climate factors while endemism is related to differences in topography and to changes in precipitation levels compared to the LGM climatic conditions.
Pyroclastic Eruption Boosts Organic Carbon Fluxes Into Patagonian Fjords
Authors: Mohr Christian H. , Korup Oliver , Ulloa Héctor , Iroumé Andrés 
Published: October 2017

AbstractFjords and old‐growth forests store large amounts of organic carbon. Yet the role of episodic disturbances, particularly volcanic eruptions, in mobilizing organic carbon in fjord landscapes covered by temperate rainforests remains poorly quantified. To this end, we estimated how much wood and soils were flushed to nearby fjords following the 2008 eruption of Chaitén volcano in south‐central Chile, where pyroclastic sediments covered >12 km2 of pristine temperate rainforest. Field‐based surveys of forest biomass, soil organic content, and dead wood transport reveal that the reworking of pyroclastic sediments delivered ~66,500 + 14,600/−14,500 tC of large wood to two rivers entering the nearby Patagonian fjords in less than a decade. A similar volume of wood remains in dead tree stands and buried beneath pyroclastic deposits (~79,900 + 21,100/−16,900 tC) or stored in active river channels (5,900–10,600 tC). We estimate that bank erosion mobilized ~132,300+21,700/−30,600 tC of floodplain forest soil. Eroded and reworked forest soils have been accreting on coastal river deltas at >5 mm yr−1 since the eruption. While much of the large wood is transported out of the fjord by long‐shore drift, the finer fraction from eroded forest soils is likely to be buried in the fjords. We conclude that the organic carbon fluxes boosted by rivers adjusting to high pyroclastic sediment loads may remain elevated for up to a decade and that Patagonian temperate rainforests disturbed by excessive loads of pyroclastic debris can be episodic short‐lived carbon sources.
A Multimodel Study on Warm Precipitation Biases in Global Models Compared to Satellite Observations
Authors: Jing Xianwen , Suzuki Kentaroh , Guo Huan , Goto Daisuke , Ogura Tomoo , Koshiro Tsuyoshi , Mülmenstädt Johannes 
Published: October 2017

AbstractThe cloud‐to‐precipitation transition process in warm clouds simulated by state‐of‐the‐art global climate models (GCMs), including both traditional climate models and a high‐resolution model, is evaluated against A‐Train satellite observations. The models and satellite observations are compared in the form of the statistics obtained from combined analysis of multiple‐satellite observables that probe signatures of the cloud‐to‐precipitation transition process. One common problem identified among these models is the too‐frequent occurrence of warm precipitation. The precipitation is found to form when the cloud particle size and the liquid water path (LWP) are both much smaller than those in observations. The too‐efficient formation of precipitation is found to be compensated for by errors of cloud microphysical properties, such as underestimated cloud particle size and LWP, to an extent that varies among the models. However, this does not completely cancel the precipitation formation bias. Robust errors are also found in the evolution of cloud microphysical properties from nonprecipitating to drizzling and then to raining clouds in some GCMs, implying unrealistic interaction between precipitation and cloud water. Nevertheless, auspicious information is found for future improvement of warm precipitation representations: the adoption of more realistic autoconversion scheme in the high‐resolution model improves the triggering of precipitation, and the introduction of a sophisticated subgrid variability scheme in a traditional model improves the simulated precipitation frequency over subtropical eastern ocean. However, deterioration in other warm precipitation characteristics is also found accompanying these improvements, implying the multisource nature of warm precipitation biases in GCMs.
Open‐loop Stackelberg learning solution for hierarchical control problems
Authors: Vamvoudakis Kyriakos G. , Lewis Frank L. , Dixon Warren E. 
Published: October 2017

SummaryThis work presents a novel framework based on adaptive learning techniques to solve the continuous‐time open‐loop Stackelberg games. The method yields real‐time approximations of the game value and convergence of the policies to the open‐loop Stackelberg‐equilibrium solution, while also guaranteeing asymptotic stability of the equilibrium point of the closed‐loop system. It is implemented as a separate actor/critic parametric network approximator structure for every player and involves simultaneous continuous‐time adaptation. To introduce and implement the hierarchical structure to the coupled optimization problem, we adjoin to the leader the controller dynamics of the follower. A persistence of excitation condition guarantees convergence of both critics to the actual game values that eventually solve the hierarchical optimization problem. A simulation example shows the efficacy of the proposed approach.
Interface‐Assisted Sign Inversion of Magnetoresistance in Spin Valves Based on Novel Lanthanide Quinoline Molecules
Authors: Bedoya‐Pinto Amilcar , Miralles Sara G. , Vélez Saül , Atxabal Ainhoa , Gargiani Pierluigi , Valvidares Manuel , Casanova Fèlix , Coronado Eugenio , Hueso Luis E. 
Published: October 2017

AbstractMolecules are proposed to be an efficient medium to host spin‐polarized carriers, due to their weak spin relaxation mechanisms. While relatively long spin lifetimes are measured in molecular devices, the most promising route toward device functionalization is to use the chemical versatility of molecules to achieve a deterministic control and manipulation of the electron spin. Here, by combining magnetotransport experiments with element‐specific X‐ray absorption spectroscopy, this study shows the ability of molecules to modify spin‐dependent properties at the interface level via metal–molecule hybridization pathways. In particular, it is described how the formation of hybrid states determines the spin polarization at the relevant spin valve interfaces, allowing the control of macroscopic device parameters such as the sign and magnitude of the magnetoresistance. These results consolidate the application of the spinterface concept in a fully functional device platform.
Vacancy‐Controlled Contact Friction in Graphene
Authors: Gajurel Prakash , Kim Mina , Wang Qiang , Dai Weitao , Liu Haitao , Cen Cheng 
Published: October 2017

AbstractDefects‐controlled friction in graphene is of technological importance in many applications, but the underlying mechanism remains a subject of debate. Here it is shown that, during the controlled oxidation in oxygen plasma and subsequent reduction induced by high‐energy photons, the contact friction in chemical vapor deposition grown graphene is dominantly determined by the vacancies formed instead of the bonding with add‐atoms. This effect is attributed to the vacancy‐enhanced out‐of‐plane deformation flexibility in graphene, which tends to produce large puckering of graphene sheet near the contact edge and thus increases the effective contact area. Modified graphene with large contact friction has a large density of defects, but remains a good electrical conductor, in which the carrier transport is strongly affected by quantum localization effects even at room temperature. It is also found that the oxidation process in graphene is substrate‐sensitive. Comparing to monolayer graphene on SiO2 substrate, the oxidation process progresses much faster when the substrate is SrTiO3, while bilayer graphene exhibits great oxidation resistance on both substrates. The collection of observations provides important information for tailoring the mechanical, electrical, and chemical properties of graphene through selected defects and substrates.
Highly Periodic Metal Dichalcogenide Nanostructures with Complex Shapes, High Resolution, and High Aspect Ratios
Authors: Jang Sungwoo , Kim Seon Joon , Koh Hyeong‐Jun , Jang Doo Hyung , Cho Soo‐Yeon , Jung Hee‐Tae 
Published: October 2017

AbstractThe development of high resolution, high aspect ratio metal dichalcogenide nanostructures is one of the most important issues in 2D material researchers due to the potential to exploit their properties into high performance devices. In this study, for the first time a way of fabricating metal dichalcogenide nanostructures with high resolution (<50 nm scale) and high aspect ratios (>120) by chemical vapor deposition assisted secondary sputtering phenomenon is reported. This approach can universally synthesize various types of metal dichalcogenides including MoS2, WS2, and SnS2, implying the possibility for further utilization with selenides and tellurides. Also, this method can produce highly periodic complex patterns such as hole–cylinder, concentric rings, and line patterns, which are unprecedented in previous reports. The feature size and aspect ratio of the metal dichalcogenide structures can be manipulated by controlling the dimensions of the photoresist prepatterns, while the pattern resolution and layer orientation can be manipulated by controlling the thickness of the deposited metal film. It is demonstrated that nanostructures with high resolution and high aspect ratio significantly improve gas‐sensing properties compared with previous metal dichalcogenide films. It is believed that the method can be a foundation for synthesizing various materials with complex patterns for future applications.
Hierarchically Porous Carbon Photonic Structures
Authors: Gil‐Herrera Luz Karime , Pariente Jose Angel , Gallego‐Gómez Francisco , Gándara Felipe , Juárez Beatriz H. , Blanco Álvaro , López Cefe 
Published: October 2017

AbstractHierarchically porous carbon holds promise for many applications involving not only electrical, catalytic, power storage and related functionalities but, despite absorption in the visible and near‐infrared, also optical and sensing uses are envisaged. In this paper, the self‐assembly of heterogeneous core–shell and hollow carbon spheres based on polystyrene cores, their optical properties and their response to humidity are described. The remarkable high quality of the crystals permits to exploit their singular optical properties among which a very high sensitivity to adsorption of guest materials stands out. In this regard, an original characterization of the system response is performed by means of the photonic bandgap variation with the relative gas pressure. Controlled pyrolysis enables to create and tune the features of the porosity brought about by degassing and the restructuring of the carbon lattice. Functionality associated with diverse pore populations reveals sensitivity to diverse ranges of humidity owing to selective adsorption of water in different size pores.
Mercury‐Mediated Organic Semiconductor Surface Doping Monitored by Electrolyte‐Gated Field‐Effect Transistors
Authors: Zhang Qiaoming , Leonardi Francesca , Casalini Stefano , Mas‐Torrent Marta 
Published: October 2017

AbstractSurface doping allows tuning the electronic structure of semiconductors at near‐surface regime and is normally accomplished through the deposition of an ultrathin layer on top or below the host material. Surface doping is particularly appealing in organic field‐effect transistors (OFETs) where charge transport takes place at the first monolayers close to the dielectric surface. However, due to fabrication restrictions that OFET architecture imparts, this is extremely challenging. Here, it is demonstrated that mercury cations, Hg2+, can be exploited to control doping levels at the top surface of a thin film of a p‐type organic semiconductor blended with polystyrene. Electrolyte‐ or water‐gated field‐effect transistors, which have its conductive channel at the top surface of the organic thin film, turn out to be a powerful tool for monitoring the process. A positive shift of the threshold voltage is observed in the devices upon Hg2+ exposure. Remarkably, this interaction has been proved to be specific to Hg2+ with respect to other divalent cations and sensitive down to nanomolar concentrations. Hence, this work also opens new perspectives for employing organic electronic transducers in portable sensors for the detection of an extremely harmful water pollutant without the need of using specific receptors.
Hydrogen‐Bonding‐Assisted Intermolecular Charge Transfer: A New Strategy to Design Single‐Component White‐Light‐Emitting Materials
Authors: Xie Zongliang , Huang Qiuyi , Yu Tao , Wang Leyu , Mao Zhu , Li Wenlang , Yang Zhan , Zhang Yi , Liu Siwei , Xu Jiarui , Chi Zhenguo , Aldred Matthew P. 
Published: October 2017

AbstractThis study reveals the mechanism of the dual‐emission properties for asymmetrical diphenylsulfone and diphenylketone derivatives. A series of asymmetrical diphenylketone and diphenylsulfone derivatives with dual‐emission properties are designed and synthesized. By single crystal structure analyses, various photophysical studies, and 2D 1H–1H NOSEY NMR studies, the lower energy emission bands in the dual‐emission spectra are successfully assigned to hydrogen‐bonding‐assisted intermolecular charge transfer emission. The emission properties of these compounds can easily be tuned in both solid state and solution state by destroying or strengthening the intermolecular hydrogen bonding. In addition, thermally activated delayed fluorescence characteristics for the intermolecular charge transfer emissions are also observed. The control of the intermolecular and intramolecular charge transfers serves as the basis for the generation of the white‐light emission. For compound CPzPO, nearly pure white‐light emission with CIE coordinates of (0.31, 0.32) is easily achieved by precipitation from dichloromethane and hexane mixed solvent system. These results clearly give an insight into the dual‐emission properties and provide a rational strategy for the design and synthesis of single‐component white‐light‐emitting materials and mechanoresponsive light‐emitting materials.
Perfluoroaryl‐Elemental Sulfur SNAr Chemistry in Covalent Triazine Frameworks with High Sulfur Contents for Lithium–Sulfur Batteries
Authors: Je Sang Hyun , Kim Hyeon Jin , Kim Jiheon , Choi Jang Wook , Coskun Ali 
Published: October 2017

AbstractIn order to address the challenges associated with lithium–sulfur batteries with high energy densities, various approaches, including advanced designs of sulfur composites, electrolyte engineering, and functional separators, are lately introduced. However, most approaches are effective for sulfur cathodes with limited sulfur contents, i.e., <80 wt%, imposing a significant barrier in realizing high energy densities in practical cell settings. Here, elemental sulfur‐mediated synthesis of a perfluorinated covalent triazine framework (CTF) and its simultaneous chemical impregnation with elemental sulfur via SNAr chemistry are demonstrated. SNAr chemistry facilitates the dehalogenation and nucleophilic addition reactions of perfluoroaryl units with nucleophilic sulfur chains, achieving a high sulfur content of 86 wt% in the resulting CTF. The given sulfur‐impregnated CTF, named SF‐CTF, exhibits a specific capacity of 1138.2 mAh g−1 at 0.05C, initial Coulombic efficiency of 93.1%, and capacity retention of 81.6% after 300 cycles, by utilizing homogeneously distributed sulfur within the micropores and nitrogen atoms of triazine units offering high binding affinity toward lithium polysulfides.