bluuebunny/crossref_metadata_2025_split huggingface dataset:
Scalable Manufacturing of Large and Flexible Sheets of MXene/Graphene Heterostructures
Authors: Zhao Meng‐Qiang , Trainor Nicholas , Ren Chang E. , Torelli Michelle , Anasori Babak , Gogotsi Yury 
Published: March 2019

AbstractStacking different 2D materials is a promising strategy to fabricate heterostructures that combine the advantages and eliminate the associated shortcomings of individual building blocks. When used for energy storage, 2D heterostructures provide the opportunity to manufacture flexible and conductive paper electrodes, which require no binders, conductive additives, or current collectors. Here, 2D MXene/graphene heterostructured papers are manufactured by alternately stacking Ti3C2Tx MXene and reduced graphene oxide (rGO) nanosheets using spray‐assisted layer‐by‐layer assembly. Up to letter paper–sized free‐standing films can be manufactured within half an hour of spraying. When used directly as anodes for Na‐ion storage, the MXene/rGO heterostructured films exhibit improved electrochemical performance compared to pure MXene and rGO films in terms of capacity, rate performance, and cycling stability. Capacities of ≈600 mAh g−1 are achieved by the Ti3C2Tx MXene—20 wt% rGO heterostructured films at 0.25 C (≈220 mAh g−1 at 2.5 C) along with excellent cycling stability. This work demonstrates the advantages of 2D heterostructures and possibility of large‐scale manufacturing of MXene‐based materials for energy, separation, electromagnetic interference shielding, and biomedical applications.
Enhanced Li‐O2 Battery Performance in a Binary “Liquid Teflon” and Dual Redox Mediators
Authors: Balaish Moran , Gao Xiangwen , Bruce Peter G. , Ein‐Eli Yair 
Published: March 2019

AbstractLow capacity, poor rechargeability, and premature cell death are major setbacks in the operation of Li‐O2 battery, hindering its practical application. A promising approach of meeting those challenges is via the use of redox mediators (RMs), promoting Li2O2 solution phase formation upon cell discharge and an efficient oxidation on charging. The use of dual RMs decouples the electrochemical reactions at the cathode with formation/decomposition of Li2O2, resulting in improved discharge capacity, lower charge overpotential, and cycle stability. Although Li‐O2 cell performance is no longer mitigated by an insulating Li2O2, a major inherent barrier to implement viable and functioning Li‐air batteries lies in both limited O2 mass transport and pores clogging. Here, a record discharge capacity of 6 mAh cm−2 (60% increase), by combining dual RMs with “liquid Teflon” type perfluorocarbons binary system, is demonstrated. The combination of the two materials in the cell contributes to the enhanced cell performance manifested also in lower charge overpotential values throughout dozens of cycles. This is also attributed to the unique compact and an exceptionally smooth morphology of the Li2O2 deposit layers at both ends of the air cathode.
Methodologies for On‐Demand Dispersion Engineering of Waves in Metasurfaces
Authors: Pu Mingbo , Guo Yinghui , Ma Xiaoliang , Li Xiong , Luo Xiangang 
Published: March 2019

AbstractDispersion is one common yet critical property of all kinds of waves. It is related to the spatial and spectral evolution of waves in structured materials. This review gives a summary of the methodologies used for the on‐demand dispersion engineering of waves in metasurfaces, which possess many unusual properties such as extremely short wavelength, diffraction‐less directional propagation, and tunable phase shift, resulting in many exciting applications with performances beyond the limitations set by traditional geometric and physical optics. Since most metasurfaces could be continuously transformed from simple thin films, the methodologies proposed here are universal and may be applied to analyze and design various functional metasurfaces.
Construction of High‐Quality Cu(I) Complex‐Based WOLEDs with Dual Emissive Layers Achieved by an “On‐and‐Off” Deposition Strategy
Authors: Li Jiayi , Li Xiaoyue , Tan Yu , Yu Xiao , Yuan Fanglong , Liu Zhiwei , Bian Zuqiang , Jin Qionghua , Lu Zhenghong , Huang Chunhui 
Published: March 2019

AbstractInexpensive and highly luminescent Cu(I) complexes exhibit great potential as emitters in organic light‐emitting diodes (OLEDs), especially in white OLEDs (WOLEDs). In this work, two compounds 9‐(3‐(quinolin‐4‐yl)phenyl)‐9H‐carbazole (CzPQ) and 9,9′‐(quinoline‐4,6‐diylbis(3,1‐phenylene))bis(9H‐carbazole) (2CzPQ) are designed and synthesized to form Cu(I) complexes in situ by codeposition with copper iodide (CuI). The corresponding OLEDs show an orange red emission with a maximum external quantum efficiency (EQE) of 6.7%. Based on this result, an “on‐and‐off” strategy is proposed to achieve WOLEDs with the combination of Cu(I) complex layer and the pure ligand layer by controlling the shutter of CuI source on and off. The optimized WOLEDs give a maximum EQE of 2.4% with excellent Commission Internationale de L'Eclairage (CIE) coordinates of (0.32, 0.33) and a remarkable color‐rendering index (CRI) of 94. It can be forecasted that the device efficiency would be improved by tuning the chemical structure of the ligand.
Reconfigurable Terahertz Metasurface Pure Phase Holograms
Authors: Guo Jinying , Wang Teng , Zhao Huan , Wang Xinke , Feng Shengfei , Han Peng , Sun Wenfeng , Ye Jiasheng , Situ Guohai , Chen Hou‐Tong , Zhang Yan 
Published: March 2019

AbstractTerahertz (THz) radiation has many potential applications. However, comparing with the rapid development of THz sources and detectors, functional devices for THz modulation, especially the spatial modulation devices, are still insufficient. Here, a novel approach for generating arbitrary wavefronts of a THz beam is presented. By dynamically creating metasurface structures through illuminating a thin silicon wafer with femtosecond laser, which is spatially modulated, an array of reconfigurable subwavelength resonators is generated. The wavefront of the THz beam is then determined by forming spatial profiles of the Pancharatnam–Berry scattering phase by dynamically controlling the resonator orientation. Proof‐of‐concept experiments demonstrate that streaming holographic images and lenses of variable focal length can be realized in real time. The reconfigurable scheme demonstrated here is convenient and fast, and may lead to advances in a host of THz applications.
Polarization Generation and Manipulation Based on Nonlinear Plasmonic Metasurfaces
Authors: Zang Wenbo , Qin Zhaofu , Yang Xin , Chen Zhuo , Wang Shuming , Wang Zhenlin 
Published: March 2019

AbstractPolarization is one of the most important properties of light, which is also a typical dimension for light field manipulation. With specially designed meta‐atoms and tailorable phase distribution, metasurfaces have been employed to achieve arbitrary polarization state in linear regime. Moreover, metasurface is also a platform for various types of nonlinear light generation, which can be used to realize an integrated polarized light source combined with its powerful capability of polarization manipulation. Here, a nonlinear plasmonic metasurface that is able to simultaneously realize nonlinear light generation and polarization manipulation is demonstrated. Two separated second harmonic (SH) beams with orthogonal circular polarizations are achieved from a linearly polarized fundamental wave (FW), and illuminated by circularly polarized FW the same nonlinear plasmonic metasurface can generate linearly polarized SH, which can be viewed as an SH quarter‐wave plate. Furthermore, arbitrary elliptical polarized SH can also be obtained from properly designed nonlinear metasurfaces. This design provides a new approach for miniaturized light source for special polarization requirement, which may have potential applications in integrated optics.
Lead‐Free Perovskite Derivative Cs2SnCl6−xBrx Single Crystals for Narrowband Photodetectors
Authors: Zhou Jun , Luo Jiajun , Rong Ximing , Wei Peijia , Molokeev Maxim S. , Huang Yang , Zhao Jing , Liu Quanlin , Zhang Xiuwen , Tang Jiang , Xia Zhiguo 
Published: March 2019

AbstractLead‐free and stable Sn halide perovskites demonstrate tremendous potential in the field of optoelectronic devices. Here, the structure and optical properties of the “defect” perovskites Cs2SnCl6−xBrx are reported, as well as their use as photodetector materials. Millimeter‐sized Cs2SnCl6−xBrx single crystals are grown by the hydrothermal method, with the body color continuously changing from transparent to yellow and finally to dark red. Narrowband single‐crystal photodetectors using Cs2SnCl6−xBrx crystals are presented, which show a high detectivity of ≈2.71 × 1010 Jones, with narrowband photodetection (full‐width at half‐maximum ≈45 nm) and high ion diffusion barriers. Moreover, the response spectra are continuously tuned from near violet to orange depending on the variation of the bandgap of the single crystals by changing the halide compositions. The strong surface charge recombination of the excess carriers near the crystal surfaces produced by short wavelength light elucidates the narrowband photodetection behavior. This work provides a new paradigm in the design of lead‐free, stable, and high‐performance perovskite derivatives for optoelectronics applications.
Gold Nanoparticles with Selective Antileukemic Activity In Vitro and In Vivo Target Mitochondrial Respiration
Authors: Gaiser Ann‐Kathrin , Hafner Susanne , Schmiech Michael , Büchele Berthold , Schäfer Patrick , von Arnim Christine A. , Calzia Enrico , Feuring‐Buske Michaela , Buske Christian , Vick Binje , Jeremias Irmela , Syrovets Tatiana , Simmet Thomas 
Published: March 2019

AbstractThis study explores biocompatible amino‐functionalized gold nanoparticles (Au‐NH2) as nanotherapeutics for the selective eradication of leukemia cells, elucidates the mechanism of cytotoxicity, and it confirms in vivo efficacy of the engineered nanomaterial. Au‐NH2 trigger apoptotic cell death of myeloid leukemia cell lines and primary acute myeloid leukemia (AML) cells by i) inhibition of mitochondrial respiration, ii) ATP depletion, iii) loss of mitochondrial membrane potential, and iv) mitochondrial release of cytochrome c. Au‐NH2 act selectively on leukemia cells inasmuch as the viability of normal peripheral blood mononuclear cells and macrophages as well as the colony formation of hematopoietic stem cells remain basically unaffected. The selectivity of Au‐NH2 for AML cells can be attributed to both the preferential accumulation of AuNH2 in AML cells and the strong dependence of those cells on mitochondrial oxidative phosphorylation for ATP production. Importantly, Au‐NH2 applied either as monotherapy or as a cytarabine combination regimen possess antileukemic efficacy in the absence of adverse events in mice xenografted with primary human AML in vivo. The engineered material may pave the way for a novel nanotherapeutic treatment of AML.
Proton‐Irradiation Effects on the Thermoelectric Properties of Flexible Bi2Te3/PEDOT:PSS Composite Films
Authors: Goo Giwon , Anoop Gopinathan , Unithrattil Sanjith , Kim Wan Sik , Lee Hye Jeong , Kim Hyun Bin , Jung Myung‐Hwan , Park Jongjun , Ko Heung Cho , Jo Ji Young 
Published: March 2019

AbstractBismuth telluride (Bi2Te3) and poly(3,4‐ethylenedioxythiophene) doped with poly(styrene sulfonate) (PEDOT:PSS) are two major inorganic and organic thermoelectric (TE) materials that are widely investigated for TE device applications. An inorganic–organic composite, based on Bi2Te3 and PEDOT:PSS possessing a high TE figure of merit, has immense potential in fabricating highly efficient and flexible TE generators. In order to achieve an enhanced TE performance, the interdependent TE parameters such as electrical conductivity and Seebeck coefficient of the composite should be decoupled. In this study, the TE properties of the composites are enhanced through the creation of additional defects in Bi2Te3 via proton irradiation. The structural variations occurred in Bi2Te3 via proton irradiation are analyzed using X‐ray diffraction, X‐ray photoelectron spectroscopy, and transmission electron microscopy, which quantitatively reveal structural damages as well as deviations from the Bi2Te3 stoichiometry. The proton irradiation‐induced antisite defects in the Bi2Te3 crystal are found to be beneficial in decoupling the interdependent TE parameters of Bi2Te3/PEDOT:PSS composite thin films, through which enhanced TE performance is achieved. The findings demonstrate that proton irradiation of Bi2Te3 is an effective method to engineer the TE properties through inducing defects in Bi2Te3 and enhancing the interaction between Bi2Te3 and PEDOT:PSS.
All‐Solid‐State On‐Chip Supercapacitors Based on Free‐Standing 4H‐SiC Nanowire Arrays
Authors: Li Weijun , Liu Qiao , Fang Zhi , Wang Lin , Chen Shanliang , Gao Fengmei , Ji Yuan , Yang Weiyou , Fang Xiaosheng 
Published: March 2019

AbstractAll‐solid‐state on‐chip SiC supercapacitors (SCs) based on free‐standing SiC nanowire arrays (NWAs) are reported. In comparison to the widely used technique based on the interdigitated fingers, the present strategy can be much more facile for constructing on‐chip SCs devices, which is directly sandwiched with a solid electrolyte layer between two pieces of SiC NWAs film without any substrate. The mass loading of active materials of on‐chip SiC SCs can be up to ≈5.6 mg cm−2, and the total device thickness is limited in ≈40 µm. The specific area energy and power densities of the SCs device reach 5.24 µWh cm−2 and 11.2 mW cm−2, and their specific volume energy and power densities run up to 1.31 mWh cm–3 and 2.8 W cm−3, respectively, which are two orders of magnitude higher than those of state‐of‐the‐art SiC‐based SCs, and also much higher than those of other solid‐state carbon‐based SCs ever reported. Furthermore, such on‐chip SCs exhibit superior rate capability and robust stability with over 94% capacitance retention after 10 000 cycles at a scan rate of 100 mV s−1, representing their high performance in all merits.
Hemodynamics and stroke risk in intracranial atherosclerotic disease
Authors: Leng Xinyi , Lan Linfang , Ip Hing Lung , Abrigo Jill , Scalzo Fabien , Liu Haipeng , Feng Xueyan , Chan Ka Lung , Fan Florence S. Y. , Ma Sze Ho , Fang Hui , Xu Yuming , Li Jingwei , Zhang Bing , Xu Yun , Soo Yannie O. Y. , Mok Vincent C. T. , Yu Simon C. H. , Liebeskind David S. , Wong Ka Sing , Leung Thomas W. 
Published: March 2019

ObjectiveTo investigate whether hemodynamic features of symptomatic intracranial atherosclerotic stenosis (sICAS) might correlate with the risk of stroke relapse, using a computational fluid dynamics (CFD) model.MethodsIn a cohort study, we recruited patients with acute ischemic stroke attributed to 50 to 99% ICAS confirmed by computed tomographic angiography (CTA). With CTA‐based CFD models, translesional pressure ratio (PR = pressurepoststenotic/pressureprestenotic) and translesional wall shear stress ratio (WSSR = WSSstenotic − throat/WSSprestenotic) were obtained in each sICAS lesion. Translesional PR ≤ median was defined as low PR and WSSR ≥4th quartile as high WSSR. All patients received standard medical treatment. The primary outcome was recurrent ischemic stroke in the same territory (SIT) within 1 year.ResultsOverall, 245 patients (median age = 61 years, 63.7% males) were analyzed. Median translesional PR was 0.94 (interquartile range [IQR] = 0.87–0.97); median translesional WSSR was 13.3 (IQR = 7.0–26.7). SIT occurred in 20 (8.2%) patients, mostly with multiple infarcts in the border zone and/or cortical regions. In multivariate Cox regression, low PR (adjusted hazard ratio [HR] = 3.16, p = 0.026) and high WSSR (adjusted HR = 3.05, p = 0.014) were independently associated with SIT. Patients with both low PR and high WSSR had significantly higher risk of SIT than those with normal PR and WSSR (risk = 17.5% vs 3.0%, adjusted HR = 7.52, p = 0.004).InterpretationThis work represents a step forward in utilizing computational flow simulation techniques in studying intracranial atherosclerotic disease. It reveals a hemodynamic pattern of sICAS that is more prone to stroke relapse, and supports hypoperfusion and artery‐to‐artery embolism as common mechanisms of ischemic stroke in such patients. Ann Neurol 2019;85:752–764
Detecting Single‐Molecule Dynamics on Lipid Membranes with Quenchers‐in‐a‐Liposome FRET
Authors: Ma Dong‐Fei , Xu Chun‐Hua , Hou Wen‐Qing , Zhao Chun‐Yu , Ma Jian‐Bing , Huang Xing‐Yuan , Jia Qi , Ma Lu , Diao Jiajie , Liu Cong , Li Ming , Lu Ying 
Published: March 2019

AbstractTracking membrane‐interacting molecules and visualizing their conformational dynamics are key to understanding their functions. It is, however, challenging to accurately probe the positions of a molecule relative to a membrane. Herein, a single‐molecule method, termed LipoFRET, is reported to assess interplay between molecules and liposomes. It takes advantage of FRET between a single fluorophore attached to a biomolecule and many quenchers in a liposome. This method was used to characterize interactions between α‐synuclein (α‐syn) and membranes. These results revealed that the N‐terminus of α‐syn inserts into the membrane and spontaneously transitions between different depths. In contrast, the C‐terminal tail of α‐syn is regulated by calcium ions and floats in solution in two conformations. LipoFRET is a powerful tool to investigate membrane‐interacting biomolecules with sub‐nanometer precision at the single‐molecule level.
Electrochemiluminescence Platforms Based on Small Water‐Insoluble Organic Molecules for Ultrasensitive Aqueous‐Phase Detection
Authors: Han Zhengang , Yang Zhaofan , Sun Heshui , Xu Yali , Ma Xiaofang , Shan Duoliang , Chen Jing , Huo Shuhui , Zhang Zhen , Du Peiyao , Lu Xiaoquan 
Published: March 2019

AbstractHighly efficient detection in the aqueous phase for water‐insoluble organic molecule probes is challenging. The bright aggregated‐state electrochemiluminescence (ECL) of 1,1‐disubstituted 2,3,4,5‐tetraphenylsiloles by a co‐reactant approach was discovered, and a heterogeneous aggregation‐induced emission ECL (HAIE‐ECL) was constructed at the electrode surface, showing very high ECL efficiency (37.8 %) and selective recognition for industrially important DNBP plasticizer with a low detection limit of 0.15 nm in the water phase. A mechanistic study indicates that ECL is mainly generated due to the high electron affinity of siloles and restriction of the intramolecular motions caused by their propeller‐like noncoplanar structures. This system realizes the sensing of organic‐based ECL in the water phase by solving the crucial problems of water insolubility and aggregation‐caused quenching (ACQ), and demonstrates potential for further application because of its design and high efficiency.
IDPi‐Katalyse
Authors: Schreyer Lucas , Properzi Roberta , List Benjamin 
Published: March 2019

AbstractHohe Acidität und sterische Einschränkung sind Schlüsselelemente bei der asymmetrischen Säure‐Katalyse. Die kürzlich eingeführten Imidodiphosphorimidat (IDPi)‐Brønsted‐Säuren haben diese Eigenschaften mit bemerkenswertem Erfolg kombiniert. Sie wirken als hochaktive Brønsted‐Säure‐Katalysatoren und als “Silylium”‐Lewis‐Säure‐Präkatalysatoren bei zahlreichen vorher nicht zugänglichen Transformationen. Schwierig zu aktivierende Substrate wie einfache Olefine ließen sich leicht umsetzen. Ketone wurden als Akzeptoren bei Aldolreaktionen eingesetzt, die eine Katalyse im Sub‐ppm‐Bereich ermöglichten, während Enolate des kleinsten Donoraldehyds, Acetaldehyd, nicht polymerisiert, sondern gezielt ein einziges Mal an eine Vielzahl von Akzeptoraldehyden gekuppelt wurden.
Rhodium‐Catalyzed Stitching Polymerization of 1,5‐Hexadiynes and Related Oligoalkynes
Authors: Ikeda Sho , Shintani Ryo 
Published: March 2019

AbstractA new mode of polymerization, rhodium‐catalyzed stitching polymerization, has been developed for the synthesis of π‐conjugated polymers with bridged repeating units from nonconjugated 1,5‐hexadiynes containing both terminal and internal alkyne moieties as monomers. The polymerization proceeded smoothly with a high degree of stitching efficiency under mild conditions, and 1,5,9‐decatriyne and 1,5,9,13‐tetradecatetrayne monomers could also be employed. The present polymerization strategy would be particularly beneficial for the synthesis of polymers consisting of a repeating unit that is difficult to prepare as a stable monomer because it does not require the use of a preformed bridged π‐conjugated monomer.
NiFe Alloy Nanoparticles with hcp Crystal Structure Stimulate Superior Oxygen Evolution Reaction Electrocatalytic Activity
Authors: Wang Changhong , Yang Hongchao , Zhang Yejun , Wang Qiangbin 
Published: March 2019

AbstractTuning the crystal phase of metal alloy nanomaterials has been proved a significant way to alter their catalytic properties based on crystal structure and electronic property. Herein, we successfully developed a simple strategy to controllably synthesize a rare crystal structure of hexagonal close‐packed (hcp) NiFe nanoparticle (NP) encapsulated in a N‐doped carbon (NC) shell (hcp‐NiFe@NC). Then, we systemically investigated the oxygen evolution reaction (OER) performance of the samples under alkaline conditions, in which the hcp‐NiFe@NC exhibits superior OER activity compared to the conventional face‐centered cubic (fcc) NiFe encapsulated in a N‐doped carbon shell (fcc‐NiFe@NC). At the current densities of 10 and 100 mA cm−2, the hcp‐NiFe@NC with Fe/Ni ratio of ≈5.4 % only needs ultralow overpotentials of 226 mV and 263 mV versus reversible hydrogen electrode in 1.0 m KOH electrolyte, respectively, which were extremely lower than those of fcc‐NiFe@NC and most of other reported NiFe‐based electrocatalysts. We proposed that hcp‐NiFe possesses favorable electronic property to expedite the reaction on the NC surface, resulting higher catalytic activity for OER. This research provides a new insight to design more efficient electrocatalysts by considering the crystal phase correlated electronic property.
Electrorheological behavior of low filled suspensions of highly anisometric montmorillonite particles
Authors: Stolyarova Dina Yu. , Kuznetsov Nikita M. , Belousov Sergey I. , Chvalun Sergei N. 
Published: March 2019

ABSTRACTThe electrorheological (ER) behavior of modified montmorillonite (MMT) suspensions in polydimethylsiloxane is studied. As established by rotational viscometry, the samples with a dispersed phase concentration from 1 to 8 wt % reveal viscous Newtonian behavior and dramatically change their properties to elastic when electric field is applied. The rheological characteristics of the suspensions over 0–7 kV mm−1 range of electric field strengths are also studied. Novel X‐ray diffraction method is developed to evaluate the suspension of the filler in a siloxane medium and to calculate the degree of its exfoliation. The dependence of exfoliation degree, dielectric, and ER characteristics on the type of modifier in the MMT structure is considered. Based on the obtained data, a new model of system behavior with the various types of fillers is proposed and the prospects of utilizing MMT as a filler for ER fluids are demonstrated. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47678.