bluuebunny/crossref_metadata_2025_split huggingface dataset:
In Situ Formation of Copper‐Based Hosts Embedded within 3D N‐Doped Hierarchically Porous Carbon Networks for Ultralong Cycle Lithium–Sulfur Batteries
Authors: Yu Qiuhong , Lu Yang , Luo Rongjie , Liu Xianming , Huo Kaifu , Kim Jang‐Kyo , He Jun , Luo Yongsong 
Published: August 2018

AbstractLithium–sulfur (Li–S) batteries are promising energy storage systems due to their large theoretical energy density of 2600 Wh kg−1 and cost effectiveness. However, the severe shuttle effect of soluble lithium polysulfide intermediates (LiPSs) and sluggish redox kinetics during the cycling process cause low sulfur utilization, rapid capacity fading, and a low coulombic efficiency. Here, a 3D copper, nitrogen co‐doped hierarchically porous graphitic carbon network developed through a freeze‐drying method (denoted as 3D Cu@NC‐F) is prepared, and it possesses strong chemical absorption and electrocatalytic conversion activity for LiPSs as highly efficient sulfur host materials in Li–S batteries. The porous carbon network consisting of 2D cross‐linked ultrathin carbon nanosheets provides void space to accommodate volumetric expansion upon lithiation, while the Cu, N‐doping effect plays a critical role for the confinement of polysulfides through chemical bonding. In addition, after sulfuration of Cu@NC‐F network, the in situ grown copper sulfide (CuxS) embedded within CuxS@NC/S‐F composite catalyzes LiPSs conversion during reversible cycling, resulting in low polarization and fast redox reaction kinetics. At a current density of 0.1 C, the CuxS@NC/S‐F composites' electrode exhibits an initial capacity of 1432 mAh g−1 and maintains 1169 mAh g−1 after 120 cycles, with a coulombic efficiency of nearly 100%.
A pH‐Mediated Electronic Wound Dressing for Controlled Drug Delivery
Authors: Kiaee Gita , Mostafalu Pooria , Samandari Mohamadmahdi , Sonkusale Sameer 
Published: August 2018

AbstractTopical administration of drugs in a timely manner according to the physiological need at the wound site can enhance the healing rate of chronic wounds. Herein, an electronic wound dressing that enables active topical drug delivery in response to electrically induced pH change is demonstrated for potential treatment of chronic wounds. In this platform, the pH of the dressing is controlled using an electrical field. This allows precise electrical control over the temporal profile of pH‐mediated drug release. This engineered dressing is comprised of microfabricated electrodes serving as anode and cathode, a pH sensitive hydrogel, and controlled electronic circuitry. The anode is coated with a pH sensitive poly(ethylene glycol)‐diacrylate/Laponite hydrogel layer containing drug loaded chitosan nanoparticles (ChPs). Applying a DC voltage between the electrodes results in a local change in pH near the electrodes. In basic environments found near the anode, the ChPs release their drug due to the dehydration process, while in acidic environments the release profile is negligible. Turning off the DC voltage results in immediate pH recovery and cessation of drug release. The biocompatibility of the dressing has also been confirmed—the pH shift resulting from application of DC voltage does not affect the wound pH significantly.
Control of Domain Structures in Multiferroic Thin Films through Defect Engineering
Authors: Li Linze , Jokisaari Jacob R. , Zhang Yi , Cheng Xiaoxing , Yan Xingxu , Heikes Colin , Lin Qiyin , Gadre Chaitanya , Schlom Darrell G. , Chen Long‐Qing , Pan Xiaoqing 
Published: August 2018

AbstractDomain walls (DWs) have become an essential component in nanodevices based on ferroic thin films. The domain configuration and DW stability, however, are strongly dependent on the boundary conditions of thin films, which make it difficult to create complex ordered patterns of DWs. Here, it is shown that novel domain structures, that are otherwise unfavorable under the natural boundary conditions, can be realized by utilizing engineered nanosized structural defects as building blocks for reconfiguring DW patterns. It is directly observed that an array of charged defects, which are located within a monolayer thickness, can be intentionally introduced by slightly changing substrate temperature during the growth of multiferroic BiFeO3 thin films. These defects are strongly coupled to the domain structures in the pretemperature‐change portion of the BiFeO3 film and can effectively change the configuration of newly grown domains due to the interaction between the polarization and the defects. Thus, two types of domain patterns are integrated into a single film without breaking the DW periodicity. The potential use of these defects for building complex patterns of conductive DWs is also demonstrated.
Directed Molecular Collection by E‐Jet Printed Microscale Chemical Potential Wells in Hydrogel Films
Authors: Zhang Shiyan , Kieffer Spencer J. , Zhang Chunjie , Alleyne Andrew G. , Braun Paul V. 
Published: August 2018

AbstractA facile approach to locally concentrate analytes of interest will significantly enhance miniaturized, integrated chemical‐analysis systems. Here, the directed analyte transport and concentration using ≈200 µm‐diameter E‐jet printed chemical potential wells in a polyacrylamide hydrogel is demonstrated. Using a cationic well as the model system, anionic analytes are accumulated into a microscale area with a local concentration enhancement of >50‐fold relative to the surrounding area. By downscaling the diameter of the chemical potential well from a few millimeters to 100s of micrometers, it is found, using both fluorescence and Raman microscopy, that the molecular collection capacity of the well is greatly improved. Additionally, it is shown that molecules can be simultaneously transported and concentrated to arrays of microscale regions using an array of microscale chemical potential wells. This approach enhances many‐fold the limit of detection, enables the formation of microscale potential well arrays with a variety of chemical properties, and provides a novel microscale molecular manipulation technique as an alternative to traditional microfluidic‐based systems.
2D Magnetic Mesocrystals for Bit Patterned Media
Authors: Guo Shanshan , Xu Feng , Wang Baomin , Wang Ning , Yang Huali , Dhanapal Pravarthana , Xue Fei , Wang Junling , Li Run‐Wei 
Published: August 2018

AbstractBit patterned media exhibits great potential in satisfying the increasing demand for higher information storage density, but the present media fabrication technique is complicated. Here, a 2D magnetic mesocrystal with monodisperse CoFe2O4 (CFO) nanocrystals is fabricated through a combination of nanoseeds layer growth and oxides self‐assembly method. The monodisperse CFO nanomagnets protrude from the substrate surface with perfect crystal facets, specific crystallographic orientation, and are fully relaxed. Systematic magnetic characterizations, such as dynamic cantilever magnetometry for single CFO nanocrystal, magnetic force microscopy, and superconducting quantum interference device magnetometry for large area, reveal the novel tilted magnetic anisotropy and the switchable single domain state. This work provides a new way to fabricate bit patterned media with controlled material structure simply by a nanoseeds‐mediated self‐assembly method.
Light Emission Properties of 2D Transition Metal Dichalcogenides: Fundamentals and Applications
Authors: Zheng Weihao , Jiang Ying , Hu Xuelu , Li Honglai , Zeng Zhouxiaosong , Wang Xiao , Pan Anlian 
Published: August 2018

Abstract2D transition metal dichalcogenides (2D TMDs) with energy bandgaps covering the visible and near infrared spectral region have enormous advantages in various photonic and optoelectronic applications, such as light emitting devices, transistors, photovoltaic devices, photodetectors, and nanocavity lasers. Understanding the mechanisms and controlling the optical properties of 2D TMDs is of crucial importance for further applications in integrated photonics. This review focuses on the light emission properties of 2D TMDs and their heterojunctions (HJs), including the fundamentals, tunability, and device applications. The band structures and excitonic properties related to light emission in 2D TMDs are discussed. The approaches to control, tune, and enhance light emission are also discussed. Subsequently, the light emission phenomena in 2D TMD HJs and their mechanisms associated with interlayer exciton, charge transfer, and energy transfer processes are described. Finally, the future potentials and challenges in TMD photonics are presented.
Improving the Stability of an RT‐NaS Battery via In Situ Electrochemical Formation of Protective SEI on a Sulfur–Carbon Composite Cathode
Authors: Lee Hwon‐gi , Lee Jung Tae , Eom KwangSup 
Published: August 2018

AbstractThe room temperature sodium sulfur battery (RT‐NaS) has attracted considerable attention as a next‐generation energy storage system due to its low cost and high specific energy and the abundance of sodium and sulfur. However, the sulfur‐based cathode in RT‐NaS always undergoes dissolution of polysulfides during the cycle, which limits the utilization of active material and the stability of the RT‐NaS. In this study, the authors report an economical and simple method to suppress the dissolution of polysulfides by forming an artificial protective solid electrolyte interphase (SEI) on the cathode surface using an in situ electrochemical treatment with a fluoroethylene carbonate (FEC) electrolyte additive. The artificially formed SEI has a thickness of ≈20 nm and contains fluoride anions that improve electrical conductivity and mechanical stability. The RT‐NaS full cell with the sulfur–carbon cathode and protective SEI exhibits a 0.1 VNa+/Na lower electrochemical polarization for desodiation, and SEI and electrical resistances that are 23% and 45% lower, respectively, than those of untreated NaS. These improvements lead to a capacity increase of ≈120% (270 to 590 mAh g−1 at the 50th cycle) and a high Coloumbic efficiency of 99.5% in the high‐rate cyclability test of the 2 C rate over 200 cycles.
Enhanced CO2/CH4 Separation Performance of a Mixed Matrix Membrane Based on Tailored MOF‐Polymer Formulations
Authors: Liu Yang , Liu Gongping , Zhang Chen , Qiu Wulin , Yi Shouliang , Chernikova Valeriya , Chen Zhijie , Belmabkhout Youssef , Shekhah Osama , Eddaoudi Mohamed , Koros William 
Published: August 2018

AbstractMembrane‐based separations offer great potential for more sustainable and economical natural gas upgrading. Systematic studies of CO2/CH4 separation over a wide range of temperatures from 65 °C (338 K) to as low as −40 °C (233 K) reveals a favorable separation mechanism toward CO2 by incorporating Y‐fum‐fcu‐MOF as a filler in a 6FDA‐DAM polyimide membrane. Notably, the decrease of the temperature from 308 K down to 233 K affords an extremely high CO2/CH4 selectivity (≈130) for the hybrid Y‐fum‐fcu‐MOF/6FDA‐DAM membrane, about four‐fold enhancement, with an associated CO2 permeability above 1000 barrers. At subambient temperatures, the pronounced CO2/CH4 diffusion selectivity dominates the high permeation selectivity, and the enhanced CO2 solubility promotes high CO2 permeability. The differences in adsorption enthalpy and activation enthalpy for diffusion between CO2 and CH4 produce the observed favorable CO2 permeation versus CH4. Insights into opportunities for using mixed‐matrix membrane‐based natural gas separations at extreme conditions are provided.
Fabrication of Hierarchical Potassium Titanium Phosphate Spheroids: A Host Material for Sodium‐Ion and Potassium‐Ion Storage
Authors: Wei Zhixuan , Wang Dongxue , Li Malin , Gao Yu , Wang Chunzhong , Chen Gang , Du Fei 
Published: August 2018

AbstractIdentifying suitable electrode materials for sodium‐ion and potassium‐ion storage holds the key to the development of earth‐abundant energy‐storage technologies. This study reports an anode material based on self‐assembled hierarchical spheroid‐like KTi2(PO4)3@C nanocomposites synthesized via an electrospray method. Such an architecture synergistically combines the advantages of the conductive carbon network and allows sufficient space for the infiltration of the electrolyte from the porous structure, leading to an impressive electrochemical performance, as reflected by the high reversible capacity (283.7 mA h g−1 for Na‐ion batteries; 292.7 mA h g−1 for K‐ion batteries) and superior rate capability (136.1 mA h g−1 at 10 A g−1 for Na‐ion batteries; 133.1 mA h g−1 at 1 A g−1 for K‐ion batteries) of the resulting material. Moreover, the different ion diffusion behaviors in the two systems are revealed to account for the difference in rate performance. These findings suggest that KTi2(PO4)3@C is a promising candidate as an anode material for sodium‐ion and potassium‐ion batteries. In particular, the present synthetic approach could be extended to other functional electrode materials for energy‐storage materials.
Self‐Assemble and In Situ Formation of Ni1−xFexPS3 Nanomosaic‐Decorated MXene Hybrids for Overall Water Splitting
Authors: Du Cheng‐Feng , Dinh Khang Ngoc , Liang Qinghua , Zheng Yun , Luo Yubo , Zhang Jianli , Yan Qingyu 
Published: August 2018

AbstractHerein, the authors present the development of novel 0D–2D nanohybrids consisting of a nickel‐based bimetal phosphorus trisulfide (Ni1−xFexPS3) nanomosaic that decorates on the surface of MXene nanosheets (denoted as NFPS@MXene). The nanohybrids are obtained through a facile self‐assemble process of transition metal layered double hydroxide (TMLDH) on MXene surface; followed by a low temperature in situ solid‐state reaction step. By tuning the Ni:Fe ratio, the as‐synthesized NFPS@MXene nanohybrids exhibit excellent activities when tested as electrocatalysts for overall water splitting. Particularly, with the initial Ni:Fe ratio of 7:3, the obtained Ni0.7Fe0.3PS3@MXene nanohybrid reveals low overpotential (282 mV) and Tafel slope (36.5 mV dec−1) for oxygen evolution reaction (OER) in 1 m KOH solution. Meanwhile, the Ni0.9Fe0.1PS3@MXene shows low overpotential (196 mV) for the hydrogen evolution reaction (HER) in 1 m KOH solution. When integrated for overall water splitting, the Ni0.7Fe0.3PS3@MXene || Ni0.9Fe0.1PS3@MXene couple shows a low onset potential of 1.42 V and needs only 1.65 V to reach a current density of 10 mA cm−2, which is better than the all noble metal IrO2 || Pt/C electrocatalyst (1.71 mV@10 mA cm−2). Given the chemical versatility of Ni1−xFexPS3 and the convenient self‐assemble process, the nanohybrids demonstrated in this work are promising for energy conversion applications.
Stinging hair morphology and wall biomineralization across five plant families: Conserved morphology versus divergent cell wall composition
Authors: Mustafa Adeel , Ensikat Hans‐Jürgen , Weigend Maximilian 
Published: August 2018

Premise of the StudyStinging hairs are striking examples of plant microengineering—the plant equivalent of the hypodermic syringe. The requisite mechanical properties are mostly achieved by cell wall mineralization. Stinging hairs of Urtica dioica (Urticaceae) are known to be mineralized with silica and calcium carbonate and those of Loasaceae also with calcium phosphate, but no comparative study has been provided across different taxa with stinging hairs.MethodsLight microscopy and scanning electron microscopy (SEM) with cryo‐SEM and energy‐dispersive x‐ray spectroscopy were used to analyze morphology and biomineralization of stinging hairs of 43 species from the families Caricaceae, Euphorbiaceae, Loasaceae, Namaceae, and Urticaceae.Key ResultsStinging hair morphology is similar across the taxa studied, in striking contrast to the divergent patterns of biomineralization. Trichome bases are mostly calcified, sometimes silicified, the shafts are mostly calcified, and the apices silicified (Urticaceae), and contain calcium phosphate (Caricaceae, Namaceae), both silica and calcium phosphate (some Loasaceae), or no minerals (Cnidoscolus, Euphorbiaceae). Some stinging hairs are superficially thinly coated with silica over a cell wall otherwise mineralized with calcium carbonate or calcium phosphate.ConclusionsMineralization patterns are surprisingly diverse and involve three different biominerals deposited in different parts of individual trichomes with calcium phosphate a common component. The physical properties of different wall regions of the stinging trichomes are thus fine‐tuned to optimize their function via modulation of wall thickness and differential element deposition. Similar function is apparently achieved through divergent wall compositions.
Base‐Promoted Metal‐/Oxidant‐Free Three‐Component Tandem Annulation: A Strategy for the Construction of 2,4,5‐Trisubstituted Thiazoles via C−N Bond Cleavage of Amidines
Authors: Guo Wei , Zhao Mingming , Tan Wen , Zheng Lvyin , Tao Kailiang , Chen Luyan , Wang Mingfeng , Chen Deliang , Fan Xiaolin 
Published: August 2018

AbstractA base‐promoted and metal‐/oxidant‐free one‐pot three‐component tandem annulation of amidines, aryl/alkyl isothiocyanates, and α‐bromoesters/ketones to 2,4,5‐trisubstituted thiazoles is described. This operationally simple protocol involves a base‐promoted C−N bond cleavage of amidines and features readily available starting materials, excellent functional group tolerance, and high step‐economy. It leads to the preparation of 2,4,5‐trisubstituted thiazoles efficiently and has potential applications in the field of drug screening and modification.
Copper‐Catalyzed Esterification of N‐Heteroaryl Methanes by Oxidative Dehydrogenation
Authors: Chen Xue , Liu Min , Liu Yongping , Chen Yi , Au Chak‐Tong , Yin Shuang‐Feng 
Published: August 2018

AbstractCopper‐catalyzed cross‐dehydrogenative esterification of readily available N‐heteroaryl methanes with acids has been realized in good to excellent yields of target products. Through simple regulation of acid loading, it is possible to achieve mono‐ or di‐esterification of the methyl group with high chemoselectivity. The protocol is suitable for a wide scope of substrates and exhibits high step efficiency and atom economy. It is envisaged that this radical‐promoted one‐pot dual functionalization of C(sp3)−H bond is a general and facile strategy that would enrich the applications of N‐heteroaryl methanes.
Enzyme‐Mediated, Site‐Specific Protein Coupling Strategies for Surface‐Based Binding Assays
Authors: Ott Wolfgang , Durner Ellis , Gaub Hermann E. 
Published: August 2018

AbstractCovalent surface immobilization of proteins for binding assays is typically performed non‐specifically via lysine residues. However, receptors that either have lysines near their binding pockets, or whose presence at the sensor surface is electrostatically disfavoured, can be hard to probe. To overcome these limitations and to improve the homogeneity of surface functionalization, we adapted and optimized three different enzymatic coupling strategies (4′‐phosphopantetheinyl transferase, sortase A, and asparaginyl endopeptidase) for biolayer interferometry surface modification. All of these enzymes can be used to site‐specifically and covalently ligate proteins of interest via short recognition sequences. The enzymes function under mild conditions and thus immobilization does not affect the receptors’ functionality. We successfully employed this enzymatic surface functionalization approach to study the binding kinetics of two different receptor–ligand pairs.
Die facettenreiche Reaktivität heterogener Einzelatom‐Katalysatoren
Authors: Mitchell Sharon , Vorobyeva Evgeniya , Pérez‐Ramírez Javier 
Published: August 2018

AbstractHeterogene Einzelatom‐Katalysatoren (single‐atom heterogeneous catalysts, SACs) finden aufgrund ihrer maximalen Reaktivität pro Metallatom und der einfachen Wiederverwendbarkeit großen Anklang in der akademischen Welt. Jedoch führt der Weg von Nanopartikeln oder Metallclustern zu schließlich einzeln isolierten Atomen zwangsläufig zu Veränderungen in der Reaktivität der Katalysatoren, da die physikalische Struktur der aktiven Zentren verändert wird. Hier bewerten wir durch den Vergleich verschiedenster Anwendungen, ob die katalytische Leistungsfähigkeit durch die Verwendung von SACs verbessert oder verschlechtert wird. Zudem stellen wir fest, dass SACs im Allgemeinen einzigartige katalytische Zyklen aufweisen. Die Wahl des Trägermaterials ist maßgebend, da dieses sowohl die elektronischen als auch die sterischen Eigenschaften des Metallzentrums beeinflusst. Außerdem kann der Träger auch als Cokatalysator wirken. Für die Entwicklung neuer SACs, welche die begehrenswerten Eigenschaften ihrer homogenen oder heterogenen Vorgänger vereinen können, müssen all diese Aspekte berücksichtigt werden. Schließlich könnten SACs auch homogene Metallkomplexe in katalytischen Anwendungen ersetzen, bei denen sich die Heterogenisierung als besonders schwierig erweist.
Site‐Selective, Late‐Stage C−H 18F‐Fluorination on Unprotected Peptides for Positron Emission Tomography Imaging
Authors: Yuan Zheliang , Nodwell Matthew B. , Yang Hua , Malik Noeen , Merkens Helen , Bénard François , Martin Rainer E. , Schaffer Paul , Britton Robert 
Published: August 2018

AbstractPeptides are often ideal ligands for diagnostic molecular imaging due to their ease of synthesis and tuneable targeting properties. However, labelling unmodified peptides with 18F for positron emission tomography (PET) imaging presents a number of challenges. Here we show the combination of photoactivated sodium decatungstate and [18F]‐N‐fluorobenzenesulfonimide effects site‐selective 18F‐fluorination at the branched position in leucine residues in unprotected and unaltered peptides. This streamlined process provides a means to directly convert native peptides into PET imaging agents under mild aqueous conditions, enabling rapid discovery and development of peptide‐based molecular imaging tools.
Learning from a Mineral Structure toward an Ultra‐Narrow‐Band Blue‐Emitting Silicate Phosphor RbNa3(Li3SiO4)4:Eu2+
Authors: Liao Hongxu , Zhao Ming , Molokeev Maxim S. , Liu Quanlin , Xia Zhiguo 
Published: August 2018

AbstractLearning from natural mineral structures is an efficient way to develop potential host lattices for applications in phosphor converted (pc)LEDs. A narrow‐band blue‐emitting silicate phosphor, RbNa3(Li3SiO4)4:Eu2+ (RNLSO:Eu2+), was derived from the UCr4C4‐type mineral model. The broad excitation spectrum (320–440 nm) indicates this phosphor can be well matched with the near ultraviolet (n‐UV) LED chip. Owing to the UCr4C4‐type highly condensed and rigid framework, RNLSO:Eu2+ exhibits an extremely small Stokes shift and an unprecedented ultra‐narrow (full‐width at half‐maximum, FWHM=22.4 nm) blue emission band (λem=471 nm) as well as excellent thermal stability (96 %@150 °C of the initial integrated intensity at 25 °C). The color gamut of the as‐fabricated (pc)LEDs is 75 % NTSC for the application in liquid crystal displays from the prototype design of an n‐UV LED chip and the narrow‐band RNLSO:Eu2+ (blue), β‐SiAlON:Eu2+ (green), and K2SiF6:Mn4+ (red) components as RGB emitters.
Syntheses and Structures of Ruthenium Complexes Containing a Ru‐H‐Tl Three‐Center–Two‐Electron Bond
Authors: Bai Wei , Zhang Jing‐Xuan , Fan Ting , Tse Sunny Kai San , Shou Wangge , Sung Herman H. Y. , Williams Ian D. , Lin Zhenyang , Jia Guochen 
Published: August 2018

AbstractTreatment of CpRuH(PP) (PP=dppm, dppe) with TlPF6 produced [CpRu(H)(Tl)(PP)]PF6. X‐ray diffraction and computational studies suggest that the complexes contain a Ru−H−Tl 3c–2e bond and can be viewed as the first σ‐complexes of period 6 main‐group hydrides [CpRu{η2‐(H−Tl)}(PP)]PF6 or [Tl{η2‐H−RuCp(PP)}]PF6. The complexes can be stored as a solid at room temperature for days without appreciable decomposition, but are unstable in solution and evolved to the trimetallic complexes [{CpRu(PP)}2(μ‐Tl)]PF6.