bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reaction Mechanisms of Sodium‐Ion Batteries under Various Charge and Discharge Conditions in a Three‐Electrode Setup
Authors: Song Xiaona , Zhou Xunfu , Zhou Yanxue , Deng Yaoming , Meng Tao , Gao Aimei , Nan Junmin , Shu Dong , Yi Fenyun 
Published: June 2018

AbstractCharge‐discharge reaction mechanisms of sodium‐ion batteries under various condition are studied by using a three‐electrode setup of a pouch‐type sodium‐ion battery. The sodium‐ion battery is constructed by using cost‐effective ternary layered Na0.76Ni0.3Fe0.4Mn0.3O2 and commercial hard carbon as the cathode and anode materials, respectively, and 1.0 M NaPF6 in mixed carbonate solvent as the electrolyte. The electrochemical impedance spectroscopy (EIS) results and transmission electron microscopy (TEM) images show that an apparent solid‐electrolyte interphase (SEI) film is formed on anode material surface during the formation (pre‐charging) process, and the potentials for the SEI film formation of the solvents (ethylene carbonate and ethylene carbonate) and the additive (fluorinated ethylene carbonate) in the electrolyte are 2.04 and 2.79 V, respectively. The X‐ray diffraction (XRD) results demonstrate that, during charge, the crystal structure of cathode material changes significantly with the deintercalation of Na+. When the battery is charged to 5.0 V, the diffraction peak corresponding to the (002) plane disappears, as Na+ is further deintercalated, and the structure changes from the hexagonal phase to the monoclinic phase, causing the rapid degradation of the cycle performance. When the battery is overdischarged to 0 V, the EIS results and TEM images show that the SEI film is destroyed completely, and the cycle life performance is significantly deteriorated.
A Switch from Mechanistic Competition Mediated by a Combination of Temperature and Concentration Effects in the Oxidation Reaction of [FeII(N4Py/TPA)](OTf)2
Authors: Tseng Tzu‐Hsien , Chen Peter Ping‐Yu 
Published: June 2018

AbstractThe formation of [(N4Py)FeIV=O]2+ species was accomplished by the reaction of [FeII(N4Py)]2+ with 20 equivalents of tBuO2H (TBHP, 70 % in H2O). The temperature, [FeII(N4Py)]2+‐concentration and H2O‐concentration in anhydrous TBHP (5.5 m in decane) dependences of its yields and rates were analyzed to indicate that the proton migration from [(N4Py)FeII‐HOOtBu]2+ to [(N4Py)FeII‐OO⊕HtBu]2+ is the rate‐determining step followed by rapid heterolytic O−O bond cleavage of FeII‐OO⊕HtBu to FeIV=O complex. The formation of [(TPA)FeIV=O]2+ is thus revealed to be greatly enhanced by the similar oxidation of [FeII(TPA)]2+ (40 mm) with 10 equivalents of tBuO2H at −45 °C. These results demonstrate the heterolytic O−O bond cleavage of FeII‐alkylperoxo species to form FeIV=O originating from the direct reaction of iron(II) complexes/TBHP. The observation of concentration and temperature effects leads to the hypothesis that O−O bond homolysis is a kinetic control pathway and O−O bond heterolysis is a thermodynamic control pathway.
A Topotactic Synthetic Methodology for the Synthesis of Nanosized MFI Zeolites with Hierarchical Structures
Authors: Li Ang , Wang Xue , Wang Tao , Liu Huali , Gao Tunan , Fan Meihong , Huo Qisheng , Qiao Zhen‐An 
Published: June 2018

AbstractMuch effort has been invested in the designed synthesis of zeolites with nanosized and hierarchical structures in recent decades, on account of increasing demands in practical applications, especially catalysis. Herein, a new topotactic synthetic strategy is demonstrated to synthesize nanosized and hierarchical zeolites in a one‐step procedure. By using silica spheres as the adjustable amorphous precursors and tetrapropylammonium hydroxide as a structure‐directing agent, effortless control of both size and porosity can be achieved in this system with no extra templates. With a simple hydrothermal process, hierarchical zeolite spheres can be modified with acid cites (Al species incorporated in the framework). Benefitting from its mesoporosity, palladium nanoparticles are incorporated into the nanosized hierarchical zeolite, which makes the materials suitable for use in a cascade catalysis reaction of benzimidazole derivatives, including independent acid catalysis and hydrogenation sites. The nanocomposites show exceptional activity and stability in catalysis and recycling reaction. This strategy can be developed into other versatile and practicable scaffolds for advanced zeolite catalytic nanoreactor systems.
Electron Delocalization of Mixed‐Valence Diiron Sites Mediated by Group 10 Metal Ions in Heterotrimetallic Fe‐M‐Fe (M=Ni, Pd, and Pt) Chain Complexes
Authors: Liu Yu‐Chiao , Hua Shao‐An , Cheng Ming‐Chuan , Yu Li‐Chung , Demeshko Serhiy , Dechert Sebastian , Meyer Franc , Lee Gene‐Hsiang , Chiang Ming‐Hsi , Peng Shie‐Ming 
Published: June 2018

AbstractThe heterotrimetallic complexes [FeMFe(dpa)4Cl2] (M=Ni (1), Pd (2), and Pt (3); dpa−=dipyridylamido) featuring two high‐spin iron centers linked by Group 10 metals were synthesized and their physical properties were investigated. Oxidation of 1–3 with suitable oxidants in CH2Cl2 solution yielded the mixed‐valent species [1]+/2+–[3]+/2+. The solution properties of [1]0/+/2+–[3]0/+/2+ were characterized by 1H NMR and UV/Vis/NIR spectroscopy as well as spectroelectrochemisty. The mixed‐valent states of [1]+–[3]+ obtained by electrochemical or chemical oxidation are classified as class II valence delocalization. The solid‐state structures of 1–3, [1]+, [3]+, and [1]2+ were determined by single‐crystal X‐ray diffraction analysis, exhibiting a linear metal framework with an approximate D4 symmetry. The spin states and magnetic properties were studied by using SQUID magnetometry, EPR and Mössbauer spectroscopy, and DFT calculations. Antiferromagnetic interactions between terminal high‐spin iron centers are present within [1]0/+/2+–[3]0/+/2+ and the |J| values increase with the central metal ion changing from Ni to Pt. The DFT calculations reproduce the antiferromagnetic coupling and ascribe it to a σ‐type exchange pathway. The substitution of the central metal not only influences the spin–spin interactions but also the degree of electronic delocalization between the terminal iron sites along the Fe‐M‐Fe chains.
Stepwise Nucleation of Aniline: Emergence of Spectroscopic Fingerprints of the Liquid Phase
Authors: León Iker , Usabiaga Imanol , Arnaiz Pedro F. , Lesarri Alberto , Fernández José A. 
Published: June 2018

AbstractThis work deals with the controlled nucleation of aniline from the isolated molecule until formation of a moderately large aggregate: aniline nonamer. The structure of the cluster at each step of the nucleation was unravelled combining mass‐resolved IR spectroscopy and computational chemistry, demonstrating that aggregation is primarily guided by formation of extensive N−H⋅⋅⋅N hydrogen‐bond networks that give the aggregates a sort of branched backbone, in clear competition with multiple N−H/C−H⋅⋅⋅π and π⋅⋅⋅π interactions. The result is the co‐existence of close nucleation paths connecting relational aggregates. The delicate balance of molecular forces makes the aniline clusters a challenge for molecular orbital calculations and an ideal system to refine the present nucleation models. Noticeably, spectroscopic signatures characteristic of the condensed phase are apparent in the nanometer‐size aggregates formed in this work.
Insight into pH‐Dependent Formation of Manganese Oxide Phases in Electrodeposited Catalytic Films Probed by Soft X‐Ray Absorption Spectroscopy
Authors: Shaker Maryam N. , Bonke Shannon A. , Xiao Jie , Khan Munirah A. , Hocking Rosalie K. , Tesch Marc F. 
Published: June 2018

AbstractMnOx films electrodeposited under basic, neutral, and acidic conditions from an ionic liquid were investigated by means of X‐ray absorption spectroscopy at the manganese L2,3‐edges and the oxygen K‐edge. Such films can serve as catalysts for the water oxidation reaction. Previous studies showed that the catalytic activity could be controlled by varying the deposition parameters, which influence the formation of MnOx phases and the film composition. Herein the film compositions are investigated in detail, indicating different ratios of MnOx structural phases in the films. All films in the series predominately consist of varying proportions of three MnOx phases—Mn2O3, Mn3O4, and birnessite, while an increase of the average Mn oxidation state in the film is identified when going from basic to acidic conditions during electrodeposition. The contribution of these three phases shows a systematic dependency on the pH during electrodeposition. While no specific single MnOx phase was found to dominate the composition of samples that were previously found to show high catalytic activity, the X‐ray spectroscopic results revealed the compositions of those samples prepared under close to neutral conditions to be most sensitive to changes in pH.
A Method for Isolating and Characterizing Mesenchymal Stromal Cell‐derived Extracellular Vesicles
Authors: Lo Sicco Claudia , Reverberi Daniele , Pascucci Luisa , Tasso Roberta 
Published: June 2018

AbstractThe unit describes protocols for isolating and characterizing extracellular vesicles (EVs) derived from human adipose tissue‐derived mesenchymal stromal cells (MSCs). EVs are a mixed population of membrane‐surrounded structures with overlapping composition and size. Advances made in recent years have led to a better understanding of the biological role of EVs. In particular, they can be considered key factors responsible for MSC‐paracrine activity, mediating their anti‐inflammatory effects towards innate immune cells, such as macrophages.The topics comprise description of the MSC‐conditioned medium containing vesicles preparation, EV isolation, and characterization mainly by specifically set up flow cytometry and electron microscopy approaches, and in vitro methodologies involved in testing the EV anti‐inflammatory capacity. The procedures described here can be easily reproduced and can be employed regardless of the type of progenitor cells used to secrete EVs. © 2018 by John Wiley & Sons, Inc.
Power splitting–based energy‐harvesting protocol for wireless‐powered communication networks with a bidirectional relay
Authors: Nguyen Tan N. , Tran Phuong T. , Vozňák Miroslav 
Published: June 2018

SummaryIn this paper, we apply the power splitting–based energy‐harvesting protocol to enhance the transmission between a wireless access point and a mobile user via a helping relay. The mobile user exploits the energy supplied by the access point and forwarded by the relay to transmit its own data back to the access point, again with the helping of the relay. Here, the effect of various system parameters, including power‐splitting factor and the power‐to‐noise ratio on the system performance, is rigorously studied, with closed‐form expressions for the outage probability and system throughput as the results. Furthermore, we figure out the optimal power‐splitting ratio at which the information throughput from the user to the AP is maximized, subject to the constraint on the transmitting power at the access point. All above analytical results are also supported by Monte Carlo simulation.
Shoal size as a key determinant of vulnerability to capture under a simulated fishery scenario
Authors: Thambithurai Davide , Hollins Jack , Van Leeuwen Travis , Rácz Anita , Lindström Jan , Parsons Kevin , Killen Shaun S. 
Published: June 2018

AbstractGroup living is widespread among animals and has a range of positive effects on individual foraging and predator avoidance. For fishes, capture by humans constitutes a major source of mortality, and the ecological effects of group living could carry‐over to harvest scenarios if fish are more likely to interact with fishing gears when in social groups. Furthermore, individual metabolic rate can affect both foraging requirements and social behaviors, and could, therefore, have an additional influence on which fish are most vulnerable to capture by fishing. Here, we studied whether social environment (i.e., social group size) and metabolic rate exert independent or interactive effects on the vulnerability of wild zebrafish (Danio rerio) to capture by a baited passive trap gear. Using video analysis, we observed the tendency for individual fish to enter a deployed trap when in different shoal sizes. Fish in larger groups were more vulnerable to capture than fish tested individually or at smaller group sizes. Specifically, focal fish in larger groups entered traps sooner, spent more total time within the trap, and were more likely to re‐enter the trap after an escape. Contrary to expectations, there was evidence that fish with a higherSMRtook longer to enter traps, possibly due to a reduced tendency to follow groupmates or attraction to conspecifics already within the trap. Overall, however, social influences appeared to largely overwhelm any link between vulnerability and metabolic rate. The results suggest that group behavior, which in a natural predation setting is beneficial for avoiding predators, could be maladaptive under a trap harvest scenario and be an important mediator of which traits are under harvest associated selection.
Predator–prey interactions in a ladybeetle–aphid system depend on spatial scale
Authors: Lin Wei‐Ting , Pennings Steven C. 
Published: June 2018

AbstractThe outcome of species interactions may manifest differently at different spatial scales; therefore, our interpretation of observed interactions will depend on the scale at which observations are made. For example, in ladybeetle–aphid systems, the results from small‐scale cage experiments usually cannot be extrapolated to landscape‐scale field observations. To understand how ladybeetle–aphid interactions change across spatial scales, we evaluated predator–prey interactions in an experimental system. The experimental habitat consisted of 81 potted plants and was manipulated to facilitate analysis across four spatial scales. We also simulated a spatially explicit metacommunity model parallel to the experiment. In the experiment, we found that the negative effect of ladybeetles on aphids decreased with increasing spatial scales. This pattern can be explained by ladybeetles strongly suppressing aphids at small scales, but not colonizing distant patches fast enough to suppress aphids at larger scales. In the experiment, the positive effects of aphids on ladybeetles were strongest at three‐plant scale. In a model scenario where predators did not have demographic dynamics, we found, consistent with the experiment, that both the effects of ladybeetles on aphids and the effects of aphids on ladybeetles decreased with increasing spatial scales. These patterns suggest that dispersal was the primary cause of ladybeetle population dynamics in our experiment: aphids increased ladybeetle numbers at smaller scales because ladybeetles stayed in a patch longer and performed area‐restricted searches after encountering aphids; these behaviors did not affect ladybeetle numbers at larger spatial scales. The parallel experimental and model results illustrate how predator–prey interactions can change across spatial scales, suggesting that our interpretation of observed predator–prey dynamics would differ if observations were made at different scales. This study demonstrates how studying ecological interactions at a range of scales can help link the results of small‐scale ecological experiments to landscape‐scale ecological problems.
Rivers shape population genetic structure in Mauritia flexuosa (Arecaceae)
Authors: Sander Nilo L. , Pérez‐Zavala Francisco , Da Silva Carolina J. , Arruda Joari C. , Pulido Maria T. , Barelli Marco A. A. , Rossi Ana B. , Viana Alexandre P. , Boechat Marcela S. B. , Bacon Christine D. , Cibrián‐Jaramillo Angélica 
Published: June 2018

AbstractThe Mauritia flexuosa L.f. palm is known as the “tree of life” given its importance as fundamental food and construction resources for humans. The species is broadly distributed in wet habitats of Amazonia and dry habitats of the Amazon and Orinoco river basins and in the Cerrado savanna. We collected 179 individuals from eight different localities throughout these habitats and used microsatellites to characterize their population structure and patterns of gene flow. Overall, we found high genetic variation, except in one savanna locality. Gene flow between populations is largely congruent with river basins and the direction of water flow within and among them, suggesting their importance for seed dispersal. Further, rivers have had a higher frequency of human settlements than forested sites, contributing to population diversity and structure through increased human use and consumption of M. flexuosa along rivers. Gene flow patterns revealed that migrants are sourced primarily from within the same river basin, such as those from Madeira and Tapajós basins. Our work suggests that rivers and their inhabitants are a critical element of the landscape in Amazonia and have impacted the dispersal and subsequent distribution of tropical palm species, as shown by the patterns of genetic variation in M. flexuosa.
Claw morphometrics in monitor lizards: Variable substrate and habitat use correlate to shape diversity within a predator guild
Authors: D'Amore Domenic C. , Clulow Simon , Doody J. Sean , Rhind David , McHenry Colin R. 
Published: June 2018

AbstractNumerous studies investigate morphology in the context of habitat, and lizards have received particular attention. Substrate usage is often reflected in the morphology of characters associated with locomotion, and, as a result, claws have become well‐studied ecomorphological traits linking the two. The Kimberley predator guild of Western Australia consists of 10 sympatric varanid species. The purpose of this study was to quantify claw size and shape in the guild using geometric morphometrics, and determine whether these features correlated with substrate use and habitat. Each species was assigned a Habitat/substrate group based on the substrate their claws interact with in their respective habitat. Claw morphometrics were derived for both wild caught and preserved specimens from museum collections, using a 2D semilandmark analysis. Claw shape significantly separated based on Habitat/substrate group. Varanus gouldii and Varanus panoptes claws were associated with sprinting and extensive digging. Varanus mertensi claws were for shallow excavation. The remaining species’ claws reflected specialization for some form of climbing, and differed based on substrate compliance. Varanus glauerti was best adapted for climbing rough sandstone, whereas Varanus scalaris and Varanus tristis had claws ideal for puncturing wood. Phylogenetic signal also significantly influenced claw shape, with Habitat/substrate group limited to certain clades. Positive size allometry allowed for claws to cope with mass increases, and shape allometry reflected a potential size limit on climbing. Claw morphology may facilitate niche separation within this trophic guild, especially when considered with body size. As these varanids are generalist predators, morphological traits associated with locomotion may be more reliable candidates for detecting niche partitioning than those associated directly with diet.
A dominance shift in arid savanna: An herbaceous legume outcompetes local C4 grasses
Authors: Wagner Thomas C. , Richter Johanna , Joubert David F. , Fischer Christina 
Published: June 2018

AbstractThe characteristic vegetation structure of arid savannas with a dominant layer of perennial grass is maintained by the putative competitive superiority of the C4 grasses. When this competitive balance is disturbed by weakening the grasses or favoring the recruitment of other species, trees, shrubs, single grass, or forb species can increase and initiate sudden dominance shifts. Such shifts involving woody species, often termed “shrub encroachment”, or the mass spreading of so‐called increaser species have been extensively researched, but studies on similar processes without obvious preceding disturbance are rare. In Namibia, the native herbaceous legume Crotalaria podocarpa has recently encroached parts of the escarpment region, seriously affecting the productivity of local fodder grasses. Here, we studied the interaction between seedlings of the legume and the dominant local fodder grass (Stipagrostis ciliata). We used a pot experiment to test seedling survival and to investigate the growth of Crotalaria in competition with Stipagrostis. Additional field observations were conducted to quantify the interactive effect. We found germination and growth of the legume seedlings to be facilitated by inactive (dead or dormant) grass tussocks and unhindered by active ones. Seedling survival was three times higher in inactive tussocks and Crotalaria grew taller. In the field, high densities of the legume had a clear negative effect on productivity of the grass. The C4 grass was unable to limit the recruitment and spread of the legume, and Crotalaria did outcompete the putative more competitive grass. Hence, the legume is able to spread and establish itself in large numbers and initiate a dominance shift in savannas, similar to shrub encroachment.
Where eagles soar: Fine‐resolution tracking reveals the spatiotemporal use of differential soaring modes in a large raptor
Authors: Murgatroyd Megan , Photopoulou Theoni , Underhill Les G. , Bouten Willem , Amar Arjun 
Published: June 2018

AbstractUnlike smaller raptors, which can readily use flapping flight, large raptors are mainly restricted to soaring flight due to energetic constraints. Soaring comprises of two main strategies: thermal and orographic soaring. These soaring strategies are driven by discrete uplift sources determined by the underlying topography and meteorological conditions in an area. High‐resolution GPS tracking of raptor flight allows the identification of these flight strategies and interpretation of the spatiotemporal occurrence of thermal and orographic soaring. In this study, we develop methods to identify soaring flight behaviors from high‐resolution GPS tracking data of Verreaux’s eagle Aquila verreauxii and analyze these data to understand the conditions that promote the use of thermal and orographic soaring. We use these findings to predict the use of soaring flight both spatially (across the landscape) and temporally (throughout the year) in two topographically contrasting regions in South Africa. We found that topography is important in determining the occurrence of soaring flight and that thermal soaring occurs in relatively flat areas which are likely to have good thermal uplift availability. The predicted use of orographic soaring was predominately determined by terrain slope. Contrary to our expectations, the topography and meteorology of eagle territories in the Sandveld promoted the use of soaring flight to a greater extent than in territories in the more mountainous Cederberg region. Spatiotemporal mapping of predicted flight behaviors can broaden our understanding of how large raptors like the Verreaux’s eagle use their habitat and how that links to energetics (as the preferential use of areas that maximize net energy gain is expected), reproductive success, and ultimately population dynamics. Understanding the fine‐scale landscape use and environmental drivers of raptor flight can also help to predict and mitigate potential detrimental effects of anthropogenic developments, such as mortality via collision with wind turbines.