bluuebunny/crossref_metadata_2025_split huggingface dataset:
Negatively Charged Nanosheets Significantly Enhance the Energy‐Storage Capability of Polymer‐Based Nanocomposites
Authors: Bao Zhiwei , Hou Chuangming , Shen Zhonghui , Sun Haoyang , Zhang Genqiang , Luo Zhen , Dai Zhizhan , Wang Chengming , Chen Xiaowei , Li Liangbin , Yin Yuewei , Shen Yang , Li Xiaoguang 
Published: May 2020

AbstractPolymer‐based dielectric materials play a key role in advanced electronic devices and electric power systems. Although extensive research has been devoted to improve their energy‐storage performances, it is a great challenge to increase the breakdown strength of polymer nanocomposites in terms of achieving high energy density and good reliability under high voltages. Here, a general strategy is proposed to significantly improve their breakdown strength and energy storage by adding negatively charged Ca2Nb3O10 nanosheets. A dramatically enhanced breakdown strength (792 MV m−1) and the highest energy density (36.2 J cm−3) among all flexible polymer‐based dielectrics are observed in poly(vinylidene fluoride)‐based nanocomposite capacitors. The strategy generalizability is verified by the similar substantial enhancements of breakdown strength and energy density in polystyrene‐based nanocomposites. Phase‐field simulations demonstrate that the further enhanced breakdown strength is ascribed to the local electric field, produced by the negatively charged Ca2Nb3O10 nanosheets sandwiched with the positively charged polyethyleneimine, which suppresses the secondary impact‐ionized electrons and blocks the breakdown path in nanocomposites. The results demonstrate a new horizon of high‐energy‐density flexible capacitors.
Atmosphere‐Mediated Scalable and Durable Biphilicity on Rationally Designed Structured Surfaces
Authors: Yan Xiao , Chen Feng , Zhang Xueqian , Qin Yimeng , Zhao Chongyan , Sett Soumyadip , Cha Hyeongyun , Hoque Muhammad Jahidul , Zhao Fulong , Huang Zhiyong , Miljkovic Nenad 
Published: May 2020

AbstractBiphilic surfaces having spatially distinct wetting have the potential to enable a plethora of applications ranging from fog harvesting, microfluidics, advanced manufacturing, and pumpless fluid transfer. However, complex and costly fabrication along with poor durability have hindered the widespread utilization of biphilic surfaces. Here, hierarchical biphilic micro/nanostructured surfaces passively functionalized by the atmosphere are demonstrated as a platform to create scalable and abrasion‐resistant biphilic interfaces. Biphilic hierarchical copper oxide (CuO) nanowires are fabricated on copper substrates via laser ablation followed by thermal oxidation. The surfaces spontaneously become globally superhydrophobic and locally hydrophilic due to the adsorption of airborne volatile organic compounds on the ultrahigh surface energy CuO nanowires. The curvature‐dependent spatial variation in nanowire morphology enables local roughness variation and wetting contrast without the need for selective functionalization. Coalescence‐induced droplet jumping and water vapor condensation experiments demonstrate global superhydrophobicity with discrete local hydrophilicity. In addition to enhanced fog harvesting rates, the surfaces are demonstrated to have repeatable self‐healing function with enhanced abrasion resistance compared to single‐tier structured surfaces. The work not only develops a facile method of fabricating scalable biphilic surfaces via nanoscale structure variation and atmosphere‐mediated surface modification, but also provides insights into the role of wetting contrast on droplet dynamics.
Nanoscale Molecular Building Blocks for Layer‐by‐Layer Assembly
Authors: Choi Shinyoung , Nguyen Nguyen Ngan , Lee Yangjin , Yang Seong‐Jun , Kim Kwanpyo , Cho Kilwon , Kim Cheol‐Joo 
Published: May 2020

AbstractUltrathin molecular films can be used as building blocks to enable rational design of functionalities at the molecular level. A versatile and scalable approach to fabricate transfer‐compatible ultrathin molecular films with a broad range of physiochemical properties is reported. Different molecules in layers of uniform nanoscale thickness are deposited on monolayer hexagonal boron nitride (ML h‐BN) film. Initially, the deposited molecules form islands due to limited molecular diffusion during deposition on ML h‐BN, but postannealing effectively transforms them to the thermodynamically preferred film structures. Ultrathin building blocks composed of ML h‐BN and different molecules (C60, pentacene, C44H32N2) are realized, then transferred layer‐by‐layer (L‐by‐L) to form materials with precisely controlled composition and thickness, including donor/acceptor superlattices. This approach can facilitate the integration of nanoscale molecules with different material platforms for advanced functionalities.
Leaf margins in a deciduous lineage from the Greater Cape Floristic Region track climate in unexpected directions
Authors: Frye Henry A. , Mocko Kerri , Moore Timothy E. , Schlichting Carl D. , Jones Cynthia S. 
Published: May 2020

PremiseThe functional significance of leaf margins has long been debated. In this study, we explore influences of climate, leaf lobing, woodiness, and shared evolutionary history on two leaf margin traits within the genus Pelargonium.MethodsLeaves from 454 populations of Pelargonium (161 species) were collected in the Greater Cape Floristic Region and scored for tooth presence/absence and degree of lobing. Tooth density (number of teeth per interior perimeter distance) was calculated for a subset of these. We compared five hypotheses to explain tooth presence and density using mixed effect models.ResultsTooth presence/absence was best predicted by the interaction of leaf lobing and mean annual temperature (MAT), but often in patterns opposite those previously reported: species were more likely to be toothed with warmer temperatures, particularly for unlobed and highly lobed leaves. In contrast, tooth density was best predicted by the interaction of MAT and the season of most rain; density declines with temperature as consistent with expectations, but only in winter‐rain dominated areas. Woody and nonwoody species within Pelargonium have similar associations between tooth presence/absence and MAT, contrary to the expectation that patterns within nonwoody species would be insignificant.ConclusionsWe conclude Pelargonium leaf margins show predictable responses to climate, but these responses are complex and can contradict those found for global patterns across plant communities.
Identifying the Transfer Kinetics of Adsorbed Hydroxyl as a Descriptor of Alkaline Hydrogen Evolution Reaction
Authors: Mao Baoguang , Sun Pingping , Jiang Yan , Meng Tao , Guo Donglei , Qin Jinwen , Cao Minhua 
Published: May 2020

AbstractThe key descriptor that dominates the kinetics of the alkaline hydrogen evolution reaction (HER) has not yet been unequivocally identified. Herein, we focus on the adsorbed hydroxyl (OHad) transfer process (OHad + e− ⇄ OH−) and reveal its crucial role in promoting the overall kinetics of alkaline HER based on Ni/Co‐modified MoSe2 model catalysts (Ni‐MoSe2 and Co‐MoSe2) that feature almost identical water dissociation and hydrogen adsorption energies, but evidently different activity trends in alkaline (Ni‐MoSe2 ≫ Co‐MoSe2) and acidic (Co‐MoSe2 ≥ Ni‐MoSe2) media. Experimental and theoretical calculation results demonstrate that tailoring MoSe2 with Ni not only optimizes the hydroxyl adsorption, but also promotes the desorption of OH− and the electron‐involved conversion of OHad to OH−, all of which synergistically accelerate the kinetics of OHad + e− ⇄ OH− and thereby the overall kinetics of the alkaline HER.
Ultrastable Surface‐Dominated Pseudocapacitive Potassium Storage Enabled by Edge‐Enriched N‐Doped Porous Carbon Nanosheets
Authors: Xu Fei , Zhai Yixuan , Zhang En , Liu Qianhui , Jiang Guangshen , Xu Xiaosa , Qiu Yuqian , Liu Xiaoming , Wang Hongqiang , Kaskel Stefan 
Published: May 2020

AbstractThe development of ultrastable carbon materials for potassium storage poses key limitations caused by the huge volume variation and sluggish kinetics. Nitrogen‐enriched porous carbons have recently emerged as promising candidates for this application; however, rational control over nitrogen doping is needed to further suppress the long‐term capacity fading. Here we propose a strategy based on pyrolysis–etching of a pyridine‐coordinated polymer for deliberate manipulation of edge‐nitrogen doping and specific spatial distribution in amorphous high‐surface‐area carbons; the obtained material shows an edge‐nitrogen content of up to 9.34 at %, richer N distribution inside the material, and high surface area of 616 m2 g−1 under a cost‐effective low‐temperature carbonization. The optimized carbon delivers unprecedented K‐storage stability over 6000 cycles with negligible capacity decay (252 mA h g−1 after 4 months at 1 A g−1), rarely reported for potassium storage.
Using Nutritional Lipid and Sensorial Profiles for the Characterization of Turkish Olive (Memecik X Gemlik cv) Hybrids obtained from Controlled Crossbreeding
Authors: Dıraman Harun , Karaman Hanife Telli , Sefer Filiz , Ersoy Nurhayat , Arsel Ali Haluk 
Published: May 2020

AbstractOlive breeding is an important method for improving of olive oil quality. In the early 1990’s, a controlled cross breeding project was started on Turkish domestic olive cultivars by Bornova Olive Research Institute, Izmir. This study was carried out with a total of 11 hybrids and 2 parents and these oil samples were obtained from “Memecik” [5 samples (MG) + 1 parent (MEM)] and “Gemlik” [6 samples (GM) + 1 parent (GEM)] domestic olive cultivars grown under the same agronomic and pedoclimatic conditions. In this study, agronomic criteria (ripening index), some nutritional values (total phenolic contents, major fatty acids [palmitic, oleic, linoleic acid, linolenic acid] and their parameters (linoleic/linolenic ratio, quality index), and sensory properties (panel test) of olive (Memecik and Gemlik) hybrid oils were analyzed during 2005–2008 four harvest years. All results showed that 11 advanced domestic olive hybrids had different oil characteristics relative to the parents of hybrids based on nutritional and sensory profiles. The Pearson correlation coefficients and principal components factor loadings observed among chemical/sensory characteristics and fatty acid profile (GM 19, GM 39, MG 11, MG 5 and MG 123 promising hybrids) could be of interest in future olive breeding programs. Considering the main objectives of olive breeding project, the hybrids of GM 19 and MG 5 exhibited superior agronomic (maturation–regular yield), technological–nutritional (high total polyphenol content, balanced omega3/omega6 ratio), and sensorial (high pungent and bitter qualifications) features. The official registrations of these hybrids were carried out by Ministry of Agriculture and Forestry of Turkey.
A 4.8 V Reversible Li2CoPO4F/Graphite Battery Enabled by Concentrated Electrolytes and Optimized Cell Design
Authors: Ko Seongjae , Yamada Yuki , Yamada Atsuo 
Published: May 2020

AbstractElevating the voltage of lithium‐ion batteries (currently 3.8 V) is a simple and pragmatic way to achieve high‐density energy storage. Many so‐called “5 V‐class” cathodes have been discovered over the past decade; however, they have been studied below 5 V (vs. Li/Li+) because of the severe oxidation of electrolytes and other cell components. Here, highly reversible charge‐discharge cycling of Li2CoPO4F/graphite full‐cells up to a cut‐off voltage of 5.2 V is demonstrated for the first time. This result is achieved with synergetic effects of an optimized cell design and a newly designed concentrated electrolyte based on LiBF4, propylene carbonate (PC), and fluoroethylene carbonate (FEC). As an electrolyte design rationale, two important properties of high oxidation stability and anode‐passivation ability are clearly allocated for LiBF4 and FEC, respectively. Besides, all other cell components (e. g., conductive carbon, separator, and binder) are reconsidered and customized for use at >5 V. The new concentrated electrolyte and optimized cell design presented here will pave the way for developing over‐5 V rechargeable batteries.
High Cycling Stability for Solid‐State Li Metal Batteries via Regulating Solvation Effect in Poly(Vinylidene Fluoride)‐Based Electrolytes
Authors: Zhang Xue , Han Jian , Niu Xiangfu , Xin Chengzhou , Xue Chuanjiao , Wang Shuo , Shen Yang , Zhang Liang , Li Liangliang , Nan Ce‐Wen 
Published: May 2020

AbstractSolid polymer electrolytes have emerged as promising alternatives to current liquid electrolytes due to their advantages in battery safety and stability. Among various polymer electrolytes, poly(vinylidene fluoride) (PVDF)‐based electrolytes with high ionic conductivity, large mechanical strength, and excellent electrochemical and thermal stability have a great potential for practical applications. However, fundamental issues, such as how the Li ions transport in the PVDF‐based electrolytes and how the residual solvent affects the cell performance, are unclear. Here, we demonstrate that the solvation effect due to a small amount of residual N,N‐dimethylformamide (DMF) bound into the electrolytes plays a critical role in ionic transport, interface stability, and cell performance. With the residual DMF existing in the electrolytes in a bound state not as free solvent, the ionic conduction could be realized by the Li‐ion transport among the interaction sites between the bound DMF and PVDF chains. Regulating the solvation effect in the electrolytes can make the PVDF‐based solid‐state Li metal batteries a significantly improved cycling performance at 25 °C (e. g., over 1000 cycles with a capacity retention of more than 94 %). These findings would promote the development of next‐generation Li metal batteries with high energy density and safety.
Zinc Deficiency Leads to Lipid Changes in Drosophila Brain Similar to Cognitive‐Impairing Drugs: An Imaging Mass Spectrometry Study
Authors: Philipsen Mai H. , Gu Chaoyi , Ewing Andrew G. 
Published: May 2020

AbstractSeveral diseases and disorders have been suggested to be associated with zinc deficiency, especially learning and memory impairment. To have better understanding about the connection between lipid changes and cognitive impairments, we investigated the effects of a zinc‐chelated diet on certain brain lipids of Drosophila melanogaster by using time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS). The data revealed that there are increases in the levels of phosphatidylcholine and phosphatidylinositol in the central brains of the zinc‐deficient flies compared to the control flies. In contrast, the abundance of phosphatidylethanolamine in the brains of the zinc‐deficient flies is lower. These data are consistent with that of cognitive‐diminishing drugs, thus providing insight into the biological and molecular effects of zinc deficiency on the major brain lipids and opening a new treatment target for cognitive deficit in zinc deficiency.
Two‐photon Absorption in a Defect‐engineered Carbon Nitride Polymer Drives Red‐light Photocatalysis
Authors: Wang Peng , Tian Lin , Gao Xinhua , Xu Yan , Yang Pengju 
Published: May 2020

AbstractExploiting photocatalysts that harvest the solar spectrum as broadly as possible remains a high‐priority target, but is a grand challenge. Herein, for the first time, we found that bulky polymer carbon nitride (denoted as PCN) possessed excellent two‐photon absorption behavior and confirmed that the bulky PCN can efficiently drive red‐light photocatalysis by two‐photon absorption processes. Long‐wavelength‐excited fluorescence measurements and confocal laser scanning microscopy clearly revealed the existence of two‐photon absorption in PCN. Moreover, we created nitrogen vacancies on the PCN surface by increasing the polymerization temperature and confirmed the nitrogen vacancies can efficiency accelerate charge separation. As a result, bulky PCN with nitrogen vacancies showed unexpected pollutant degradation and water splitting activity under 660 nm. Additionally, PCN obtained from other precursors also exhibited competent red‐light photocatalytic performance. This work represents an important step toward developing two‐photon‐absorption PCN photocatalysts for wide solar‐spectrum utilization.
Solid Electrolyte Interphase Evolution on Lithium Metal Electrodes Followed by Scanning Electrochemical Microscopy Under Realistic Battery Cycling Current Densities
Authors: Krueger Bastian , Balboa Luis , Dohmann Jan Frederik , Winter Martin , Bieker Peter , Wittstock Gunther 
Published: May 2020

AbstractLithium metal electrodes were cycled in 1 M LiClO4 in propylene carbonate with different current densities. The local protecting properties of the solid electrolyte interphase (SEI) were probed by scanning electrochemical microscopy (SECM) in the feedback mode directly within the cell in between charging‐discharging cycles. This was enabled by placing the negative electrode into an in‐house micro‐milled cell with a central opening in the counter electrode for inserting the microelectrode. Finite element simulation of the secondary current distribution proved that the current distribution deviates only slightly in the area of the opening provided that the SECM microelectrode is retracted during the charging‐discharging cycles. The development of lithium deposits was observed by SECM and can be linked to the used charging‐discharging protocol. The Li metal of protruding deposits is significantly more active for electron transfer to the mediator than the remaining parts of the surface. The developed hardware and methodology can be directly applied to other electrolytes or other battery electrodes forming protective films.
Energiespeicherung mit Redox‐Flow‐Batterien
Authors: Novotny Jana , Quarthal Dominik , Oetken Marco 
Published: May 2020

ZusammenfassungDer Beitrag stellt neben einer auf Anolyt und Katholyt basierenden Redox‐Flow‐Batterie auch verschiedene Hybrid‐Redox‐Flow‐Batterien vor, welche allesamt den didaktischen Vorteil besitzen, dass man ihren Ladezustand anhand ihrer Farbigkeit erkennt. Einerseits kann mit der eigens entwickelten Redox‐Flow‐Zelle unter Einsatz unbedenklicher Chemikalien im Unterricht erörtert werden, wie diese Energiespeicher grundsätzlich funktionieren, andererseits kann durch die Hybrid‐Redox‐Flow‐Batterien unter Einsatz von Elektrolyten, die auf Supermarktprodukte zurückzuführen sind, ein motivierender Einstieg in das Themengebiet der stationären Energiespeichersysteme gewählt werden.
Ein neuer Sekundär‐Sprengstoff: TKX‐50
Authors: Klapötke Thomas M. 
Published: May 2020

ZusammenfassungPaolo Valpolini schrieb am 24.07.2018 über TKX‐50 im „EDR Magazine European Defence Review“ in einem Artikel zum Thema „EURENCO looks at new future energetic materiel“:„EURENCO is also looking at explosives with improved performances, which would allow to decrease the ordnance dimensions while maintaining their lethality. Eurenco aims at developing a new explosive based on molecules with higher performances but with less sensitivity and toxicity. The TKX‐50 explosive performances are already better than those of Hexogen (RDX) and Octogen (HMX) with a detonation speed that exceeds by 20 % that of current explosives. This is the road that Eurenco will follow, also aiming at compositions with a higher charge density, close to 96 % versus current 85 %. Eurenco aims at testing new molecules in 2019, these being at TRL 4‐5, while composition is still at TRL 2‐3.”
Gastric interoception and gastric myoelectrical activity in bulimia nervosa and binge‐eating disorder
Authors: van Dyck Zoé , Schulz André , Blechert Jens , Herbert Beate M. , Lutz Annika P. C. , Vögele Claus 
Published: May 2020

AbstractObjectiveIdentifying factors that control food intake is crucial to the understanding and treatment of eating disorders characterized by binge eating. In healthy individuals, stomach distension plays an important role in the development of satiation, but gastric sensations might be overridden in binge eating. The present study investigated the perception of gastric signals (i.e., gastric interoception) and gastric motility in patients experiencing binge‐eating episodes, that is, bulimia nervosa (BN) and binge‐eating disorder (BED).MethodTwenty‐nine patients with BN or BED (ED group) and 32 age‐, sex‐, and BMI‐matched healthy controls (HC group) participated in the study. The onset of satiation and stomach fullness were assessed using a novel 2‐step water load test (WLT‐II). Gastric myoelectrical activity (GMA) was measured by electrogastrography (EGG) before and after ingestion of noncaloric water.ResultsIndividuals in the ED group drank significantly more water until reporting satiation during the WLT‐II. The percentage of normal gastric myoelectrical power was significantly smaller in the ED group compared to HC, and negatively related to the number of objective binge‐eating episodes per week in patients with BN or BED. Power in the bradygastria range was greater in ED than in HC participants.DiscussionPatients with EDs have a delayed response to satiation compared to HC participants, together with abnormal GMA. Repeated binge‐eating episodes may induce disturbances to gastric motor function.
Metal prices made in China? A network analysis of industrial metal futures
Authors: Siklos Pierre L. , Stefan Martin , Wellenreuther Claudia 
Published: May 2020

AbstractIn addition to being the world's greatest consumer and producer of industrial metals, China now also features the most actively traded industrial metal futures contracts worldwide. To examine China's role in the global price formation process of industrial metal futures markets, we use a sample of 29 futures contracts traded on exchanges in the United States, the United Kingdom, India, and China. We estimate vector autoregressive models and conduct variance decompositions, which are then visualized in the form of networks. The results indicate that China, despite its role as key actor in both real and financial industrial metal markets, is a price taker.
A novel method to calculate the anomaly score of movement variability of repetitive tasks
Authors: Hiranai Kazuki , Kuramoto Akisue , Seo Akihiko 
Published: May 2020

AbstractThis study proposes a new calculation method for the anomaly score of repetitive tasks based on singular spectrum transformation (SST) that accounted for a long‐term history of human motion. To validate the efficacy of the proposed method, the calculated anomaly score was compared with movement variability computed by a traditional method and to its SST‐computed score. Eleven male participants performed repetitive lightweight material handling tasks under different work conditions and an electromagnetic tracking system measured their working posture. Movement variability and anomaly score on the shoulder and elbow joints were calculated based on measured working postures. The movement variability on the elbow flexion angle increased with time. In contrast, the anomaly score of the elbow flexion angle decreased with time, but shoulder flexion and inner rotation angles showed increased scores with the passage of time. These findings are similar to those of previous studies that stated that movement variability increased from redundant degrees of freedom available for performing multi‐joint movements; this occurred due to the development of muscle fatigue on the shoulder joint from performing repetitive tasks. On comparing this to the anomaly scores calculated by conventional SST, it was observed that the score computed by the proposed method reflected the whole trend of human motion in repetitive tasks and did not depend on local problems in working posture. Therefore, it was concluded that the new method of calculating the anomaly score is more suitable to detect changes in movement variability in repetitive tasks.