bluuebunny/crossref_metadata_2025_split huggingface dataset:
Freestanding Metallic 1T MoS2 with Dual Ion Diffusion Paths as High Rate Anode for Sodium‐Ion Batteries
Authors: Geng Xiumei , Jiao Yucong , Han Yang , Mukhopadhyay Alolika , Yang Lei , Zhu Hongli 
Published: August 2017

AbstractThis work studies for the first time the metallic 1T MoS2 sandwich grown on graphene tube as a freestanding intercalation anode for promising sodium‐ion batteries (SIBs). Sodium is earth‐abundant and readily accessible. Compared to lithium, the main challenge of sodium‐ion batteries is its sluggish ion diffusion kinetic. The freestanding, porous, hollow structure of the electrode allows maximum electrolyte accessibility to benefit the transportation of Na+ ions. Meanwhile, the metallic MoS2 provides excellent electron conductivity. The obtained 1T MoS2 electrode exhibits excellent electrochemical performance: a high reversible capacity of 313 mAh g−1 at a current density of 0.05 A g−1 after 200 cycles and a high rate capability of 175 mAh g−1 at 2 A g−1. The underlying mechanism of high rate performance of 1T MoS2 for SIBs is the high electrical conductivity and excellent ion accessibility. This study sheds light on using the 1T MoS2 as a novel anode for SIBs.
Synthetic Control of Kinetic Reaction Pathway and Cationic Ordering in High‐Ni Layered Oxide Cathodes
Authors: Wang Dawei , Kou Ronghui , Ren Yang , Sun Cheng‐Jun , Zhao Hu , Zhang Ming‐Jian , Li Yan , Huq Ashifia , Ko J. Y. Peter , Pan Feng , Sun Yang‐Kook , Yang Yong , Amine Khalil , Bai Jianming , Chen Zonghai , Wang Feng 
Published: August 2017

AbstractNickel‐rich layered transition metal oxides, LiNi1−x(MnCo)xO2 (1−x ≥ 0.5), are appealing candidates for cathodes in next‐generation lithium‐ion batteries (LIBs) for electric vehicles and other large‐scale applications, due to their high capacity and low cost. However, synthetic control of the structural ordering in such a complex quaternary system has been a great challenge, especially in the presence of high Ni content. Herein, synthesis reactions for preparing layered LiNi0.7Mn0.15Co0.15O2 (NMC71515) by solid‐state methods are investigated through a combination of time‐resolved in situ high‐energy X‐ray diffraction and absorption spectroscopy measurements. The real‐time observation reveals a strong temperature dependence of the kinetics of cationic ordering in NMC71515 as a result of thermal‐driven oxidation of transition metals and lithium/oxygen loss that concomitantly occur during heat treatment. Through synthetic control of the kinetic reaction pathway, a layered NMC71515 with low cationic disordering and a high reversible capacity is prepared in air. The findings may help to pave the way for designing high‐Ni layered oxide cathodes for LIBs.
δ‐Doping Effects on Electronic and Energetic Properties of LaAlO3/SrTiO3 Heterostructure: First‐Principles Analysis of 23 Transition‐Metal Dopants
Authors: Cheng Jianli , Wang Yaqin , Luo Jian , Yang Kesong 
Published: August 2017

AbstractThe 2D electron gas (2DEG) formed at the interface between two insulating perovskite oxides such as LaAlO3 and SrTiO3 provides a playground for developing all‐oxide electronic devices, though improving the 2DEG mobility is still a great challenge. One possible way of improving the 2DEG mobility is via δ‐doping at the heterointerface. As a proof of concept, one recent experiment achieves an ultra‐high 2DEG mobility of 73 000 cm2 V−1 s−1 at the LaAlO3/SrTiO3 heterointerface via Mn δ‐doping. Here the electronic and energetic properties of δ‐doped LaAlO3/SrTiO3 are studied with 23 transition‐metal dopants from group 3 to group 10 using first‐principles calculations. A clear trend is found for the electron effective mass and interfacial energy change in the δ‐doped LaAlO3/SrTiO3 with various dopants, and there exists a trade‐off between achieving light effective mass bands and forming energetically favorable structures. It is found that the Fe, Co, Ni, Ru, Rh, Pd, Os, and Ir could also serve as promising candidate dopants to produce light effective mass bands and relatively high energetic stability, in addition to the experimentally confirmed Mn dopant. The findings of this study provide a wide avenue to increase the 2DEG mobility in the LaAlO3/SrTiO3 heterostructure via δ‐doping with transition metals.
Underwater Superoleophobic Wood Cross Sections for Efficient Oil/Water Separation
Authors: Vidiella del Blanco Marta , Fischer Eric Jean , Cabane Etienne 
Published: August 2017

AbstractFunctional surfaces with specific wettability are widely encountered in nature and have inspired the development of oil‐repellent materials for oil/water separation. Despite some impressive results reported, materials combining high separation efficiency together with economical and easily scalable approaches and ideally based on renewable resources have yet to be reported. In this Communication, spruce (Picea abies) wood cross sections are proposed as oil/water separation systems. The natural wood anisotropic porous microstructure directs fluid transport, and the nature of the cell wall biopolymers results in superhydrophilicity and underwater superoleophobicity. Such wood membranes can separate water from oil with high efficiency (>99%) and high flux using only gravity and without the need for prior chemical modification of the wood scaffold. Wood also provides an intrinsic solution to scalability issues.
CuInS2‐Based Quantum Dot Light‐Emitting Electrochemical Cells (QLECs)
Authors: Frohleiks Julia , Wefers Fabian , Wepfer Svenja , Hong A‐Ra , Jang Ho Seong , Nannen Ekaterina 
Published: August 2017

AbstractQuantum dot/electrolyte hybrid light‐emitting devices (QLECs) present a novel class of large‐area light‐emitting devices potentially combining the efficiency, robustness, and color‐tunability of colloidal quantum dots (QDs) with the simple device architecture and easy fabrication of light emitting electrochemical cells. In this work, a Cd‐free QLEC based on CuInS2/ZnS (CIS/ZnS) core/shell QDs is presented. The impact of the amount of ionic liquid on the QLEC device performance is systematically studied. The introduction of the additional electron injecting/hole blocking ZnO nanocrystal top layer as well as the proper adjustment of the ionic component leads to CIS‐based QLECs exceeding 350 cd m−2 in brightness.
Achieving Hybridized Local and Charge‐Transfer Excited State and Excellent OLED Performance Through Facile Doping
Authors: Yuan Wang Zhang , Bin Xin , Chen Gan , He Zihan , Liu Jun , Ma Huili , Peng Qian , Wei Bingwu , Gong Yongyang , Lu Yawei , He Gufeng , Zhang Yongming 
Published: August 2017

AbstractHybridized local and charge‐transfer (HLCT) excited states provide a new avenue for achieving high yields of singlet excitons (>25%) and outstanding electroluminescence (EL) performance in organic light‐emitting diodes (OLEDs). In this contribution, donor–acceptor (D–A) structured (Z)‐2,3‐bis[4‐(diphenylamino)phenyl]acrylonitrile (BDPACS) with aggregation‐induced emission (AIE) characteristics is demonstrated to possess HLCT excited states in low‐polarity solvents and in vacuum‐deposited neat films. However, undoped OLED devices of the same material show unexpectedly poor performances with external quantum efficiencies (EQEmax) of at most 0.41%, due to the formation of exciplexes or excimers. To alleviate this, doped devices are fabricated using low‐polarity 2‐methyl‐9,10‐di(2‐naphthyl)anthracene (MADN), which has the appropriate energy levels to serve as a host in the emissive layer and can eradicate exciplexes/excimers and moreover help achieve the HLCT state through the solid‐state solvation effect. Such devices exhibit strikingly improved EQEmax of 6.8%, as well as singlet utilization yields exceeding the theoretical limit of 25%. Furthermore, all doped devices exhibit extremely low efficiency roll‐off. These results may have significant implications for the future fabrication of high‐performance OLEDs based on AIE luminogens and HLCT emitters.
In Operando Study of High‐Performance Thermoelectric Materials for Power Generation: A Case Study of β‐Zn4sb3
Authors: Hung Le Thanh , Ngo Duc‐The , Han Li , Iversen Bo Brummerstedt , Yin Hao , Pryds Nini , Van Nong Ngo 
Published: August 2017

AbstractTo bring current thermoelectric (TE) materials achievement into a device for power generation, a full understanding of their dynamic behavior under operating conditions is needed. Here, an in operando study is conducted on the high‐performance TE material β‐Zn4Sb3 under large temperature gradient and thermal cycling via a new approach using in situ transmission electron microscopy combined with characterization of the TE properties. It is found that after 30 thermal cycles in a low‐pressure helium atmosphere the TE performance of β‐Zn4Sb3 is maintained with the figure of merit, zT, value of 1.4 at 718 K. Under a temperature gradient of 380 K (Thot = 673 K and Tcold = 293 K) operating for only 30 h, zinc whiskers gradually precipitate on the cold side of the β‐Zn4Sb3 leg. The dynamical evolution of Zn in the matrix of β‐Zn4Sb3 is found to be the source that leads to a high zT value by lowering of the thermal conductivity and electrical resistivity, but it is also the failure mechanism for the leg under these conditions. The in operando study brings deep insight into the dynamic behavior of nanostructured TE materials for tailoring future TE materials and devices with higher efficiency and longer durability.
Progress in Theoretical Study of Metal Halide Perovskite Solar Cell Materials
Authors: Xiao Zewen , Yan Yanfa 
Published: August 2017

AbstractLead halide perovskites have recently emerged as promising absorbers for fabricating low‐cost and high‐efficiency thin‐film solar cells. The record power conversion efficiency of lead halide perovskite‐based solar cells has rapidly increased from 3.8% in 2009 to 22.1% in early 2016. Such rapid improvement is attributed to the superior and unique photovoltaic properties of lead halide perovskites, such as the extremely high optical absorption coefficients and super‐long photogenerated carrier lifetimes and diffusion lengths that are not seen in any other polycrystalline thin‐film solar cell materials. In the past a few years, theoretical approaches have been extensively applied to understand the fundamental mechanisms responsible for the superior photovoltaic properties of lead halide perovskites and have gained significant insights. This review article highlights the important theoretical results reported in literature for the understanding of the unique structural, electronic, optical, and defect properties of lead halide perovskite materials. For comparison, we also review the theoretical results reported in literature for some lead‐free perovskites, double perovskites, and nonperovskites.
Fast Sodium Storage in TiO2@CNT@C Nanorods for High‐Performance Na‐Ion Capacitors
Authors: Zhu Yuan‐En , Yang Leping , Sheng Jian , Chen Yanan , Gu Haichen , Wei Jinping , Zhou Zhen 
Published: August 2017

AbstractNa‐ion capacitors have attracted extensive interest due to the combination of the merits of high energy density of batteries and high power density as well as long cycle life of capacitors. Here, a novel Na‐ion capacitor, utilizing TiO2@CNT@C nanorods as an intercalation‐type anode and biomass‐derived carbon with high surface area as an ion adsorption cathode in an organic electrolyte, is reported. The advanced architecture of TiO2@CNT@C nanorods, prepared by electrospinning method, demonstrates excellent cyclic stability and outstanding rate capability in half cells. The contribution of extrinsic pseudocapacitance affects the rate capability to a large extent, which is identified by kinetics analysis. A key finding is that ion/electron transfer dynamics of TiO2@CNT@C could be effectively enhanced due to the addition of multiwalled carbon nanotubes. Also, the biomass‐derived carbon with high surface area displays high specific capacity and excellent rate capability. Owing to the merits of structures and excellent performances of both anode and cathode materials, the assembled Na‐ion capacitors provide an exceptionally high energy density (81.2 W h kg−1) and high power density (12 400 W kg−1) within 1.0–4.0 V. Meanwhile, the Na‐ion capacitors achieve 85.3% capacity retention after 5000 cycles tested at 1 A g−1.
Enzyme Activity by Design: An Artificial Rhodium Hydroformylase for Linear Aldehydes
Authors: Jarvis Amanda G. , Obrecht Lorenz , Deuss Peter J. , Laan Wouter , Gibson Emma K. , Wells Peter P. , Kamer Paul C. J. 
Published: August 2017

AbstractArtificial metalloenzymes (ArMs) are hybrid catalysts that offer a unique opportunity to combine the superior performance of natural protein structures with the unnatural reactivity of transition‐metal catalytic centers. Therefore, they provide the prospect of highly selective and active catalytic chemical conversions for which natural enzymes are unavailable. Herein, we show how by rationally combining robust site‐specific phosphine bioconjugation methods and a lipid‐binding protein (SCP‐2L), an artificial rhodium hydroformylase was developed that displays remarkable activities and selectivities for the biphasic production of long‐chain linear aldehydes under benign aqueous conditions. Overall, this study demonstrates that judiciously chosen protein‐binding scaffolds can be adapted to obtain metalloenzymes that provide the reactivity of the introduced metal center combined with specifically intended product selectivity.
Alkynyl Thioethers in Gold‐Catalyzed Annulations To Form Oxazoles
Authors: Reddy Raju Jannapu , Ball‐Jones Matthew P. , Davies Paul W. 
Published: August 2017

AbstractNon‐oxidative, regioselective, and convergent access to densely functionalized oxazoles is realized in a functional‐group tolerant manner using alkynyl thioethers. Sulfur‐terminated alkynes provide access to reactivity previously requiring strong donor‐substituted alkynes such as ynamides. Sulfur does not act in an analogous donor fashion in this gold‐catalyzed reaction, thus leading to complementary regioselective outcomes and addressing the limitations of using ynamides.
Selective detection of Hg2+ ion in aqueous medium with the use of 3‐(pyrimidin‐2‐ylimino)indolin‐2‐one‐functionalized SBA‐15
Authors: Lashgari Negar , Badiei Alireza , Mohammadi Ziarani Ghodsi 
Published: August 2017

An isatin‐based fluorophore, 3‐(pyrimidin‐2‐ylimino)indolin‐2‐one, was grafted on a large‐pore mesoporous silica material (SBA‐15) via a two‐step modification process. The obtained material (SBA‐Is‐Py) was characterized using various techniques and the characterization showed that the ordered porous structure was preserved after the post‐grafting procedure. The optical sensing ability of SBA‐Is‐Py was studied upon the addition of a variety of metal ions and a marked fluorescence quenching by Hg2+ ion was observed. SBA‐Is‐Py exhibited excellent Hg2+‐specific luminescence quenching over various competing cations. Furthermore, linear changes of the optical properties of SBA‐Is‐Py as a function of the concentrations of Hg2+ ion were found, with a calculated detection limit of 3.28 × 10−7 M. In addition, SBA‐Is‐Py was successfully employed for the determination of Hg2+ in real water samples.
A comparative study of the effect of clay and titanium dioxide on the mechanical properties and permeability of nanocoated cotton fabrics
Authors: Glouia Yosra , Dhouib Soufien , Abid Khaled 
Published: August 2017

ABSTRACTThis paper explores a comparison of mechanical properties of nanocoated cotton fabric for coatings synthesized with two different additives: Tunisian natural clay and titanium dioxide. The natural raw clay is a mixture of various other simple clays (kaolinite, calcite, illite, and quartz) requires preparation. TiO2 and Tunisian clay were added to two different resins, polyacrylate and polyurethane, widely used for numerous textile improvements such as impermeability and brightness effects. The additives used offer the advantage of being nontoxic and widely available. First, we check the constitution of the nanocoatings via X‐ray diffraction. Then, a defined amount of the resulting solution is applied on a cotton fabric. Finally, we check the mechanical properties and barrier effects on the modified fabric. The results show that when a small amount of clay or TiO2 particles are added to resin, the tear, tensile, bursting, and abrasion strength and water and air barrier properties of the coated fabric are globally enhanced. However, the use of natural clay in the coating gives better results than TiO2. In fact, in terms of mechanical performance, it is two to nine times more efficient than the titanium dioxide coating, except for the barrier effect, which is exactly two times more efficient. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45642.
Temperature scanning stress relaxation measurements: A unique perspective for evaluation of the thermomechanical behavior of shape memory polymer blends
Authors: Chatterjee Tuhin , Vennemann Norbert , Naskar Kinsuk 
Published: August 2017

ABSTRACTShape memory polymer has the inherent capability of fixing its shape to a deformed or unconstrained shape that gives the material shape fixity and to revert back to its permanent shape that results shape recovery of the material. Temperature scanning stress relaxation (TSSR) studies of uncrosslinked and radiation crosslinked polymer blends of ethylene octene copolymer and ethylene propylene diene rubber has been carried out over a certain temperature range that gives the idea about the thermomechanical behavior of the material. With increasing radiation dose, TSSR index value of the radiation crosslinked blends increases, which is an indication of the improvement of the elasticity of the crosslinked network and thus results better shape recovery of the crosslinked blends when compared to the uncrosslinked one. Higher elasticity of the crosslinked network is also well supported by higher crosslink density and lower tension set value of the radiation crosslinked blends. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45680.
TASNOP: A tool for teaching algorithms to solve network optimization problems
Authors: da Silva Lourenço Wilson , de Araujo Lima Stanley Jefferson , Alves de Araújo Sidnei 
Published: August 2017

AbstractThis work presents the TASNOP—Teaching Algorithms for Solving Network Optimization Problems, a tool for teaching concepts and operation of some algorithms to solve Shortest Path, Maximum Flow, and Traveling Salesman problems, which are widely known and studied in graduate and undergraduate courses such as Industrial Engineering, Computer Science, Information Systems, and Logistics. Experiments carried out with undergraduate computer science students allowed to verify that the group who used TASNOP obtained better performance in the resolution of the proposed exercise, corroborating the idea that it contributed to improve the students’ understanding about the addressed content. In addition, a questionnaire answered by the same group of students evidenced the potential of TASNOP as a teaching support tool.
Synthesis of N‐Heterocycles by Reductive Cyclization of Nitro Compounds using Formate Esters as Carbon Monoxide Surrogates
Authors: Formenti Dario , Ferretti Francesco , Ragaini Fabio 
Published: August 2017

AbstractA series of alkyl and aryl formate esters were evaluated as CO sources in the Pd‐ and Pd/Ru‐catalyzed reductive cyclization of substituted nitro compounds to afford heterocycles, especially indoles. Phenyl formate was found to be the most effective, and it allowed the desired products to be obtained in excellent yields, often higher than those previously reported with pressurized CO. Through detailed experiments and kinetic studies, we were able to discern between metal‐catalyzed and base‐mediated activation of phenyl formate and confirmed that just the base was effective in catalyzing its decarbonylation.
Rapid Degradation of Rhodamine B via Poly(dopamine)‐Modified Membranes with Silver Nanoparticles
Authors: Ma Shengkui , Chen Xi , Zhao Bowu , Li Liying , Fu Weigui 
Published: August 2017

AbstractRapid and convenient removal of organic dyes from water still remains a great challenge. The fast degradation of Rhodamine B (RhB) with NaBH4 as a reducing agent catalyzed by a catalytic membrane fabricated by poly(dopamine)‐modified poly(vinylidene difluoride) (PVDF) powders and silver nanoparticles (NPs) is described. Results indicate that the catalytic membrane shows an excellent performance for RhB degradation under a static state and cross‐flow catalysis. Compared to static catalysis, cross‐flow catalysis can efficiently enhance the degradation of RhB due to the silver NPs and the high flowing rate of reactants on the membrane surface. The penetrated fluid can be directly excluded due to the RhB with a high conversion coming out from the membrane pores with silver NPs. The convenient operation avoids additional steps to separate catalysts from the system and, therefore, has a promising potential in degradation of organic dyes.
ms‐PoSW: A multi‐server aided proof of shared ownership scheme for secure deduplication in cloud
Authors: Xiong Jinbo , Zhang Yuanyuan , Lin Li , Shen Jian , Li Xuan , Lin Mingwei 
Published: August 2017

SummaryCollaborative cloud applications have become the dominant application mode in the big data era. These applications usually generate plenty of cooperative files, which share their ownerships with all collaborative participants. Data deduplication is a promising solution to improve the storage efficiency and save the user expenditure. However, it remains an open issue on how to securely prove the shared ownerships for the shared files and address the attacks on account of using data deduplication. To tackle the above issue, in this paper, we introduce a novel concept of the Proof of Shared oWnership (PoSW) and construct a secure multi‐server‐aided PoSW (ms‐PoSW) scheme for securing client‐side deduplication for the shared files, which is based on the convergent encryption, secret sharing, and bloom filter. In the ms‐PoSW scheme, we employ a sharing convergent key to avoid the single point of failure, introduce the secret sharing algorithm to implement the shared ownership, and construct a novel interaction protocol between the shared owners and the cloud server to prove the shared ownership. Furthermore, a hybrid PoSW scheme is constructed to address the secure proof of hybrid cloud architectures. Finally, security analysis and performance evaluation show the security and efficiency of the proposed schemes.
Performance formula‐based optimal deployments of multilevel indices for service retrieval
Authors: Wu Yan , Xu Wei , Liu Lu , Miao Dejun 
Published: August 2017

SummaryThere are many different index structures for service repositories, such as sequential index, inverted index, and multilevel indices that include three deployments. Different service sets maybe have different characteristics that may affect performance from different aspects. For a given service set, which index structure is the most optimal one? To address these issues, this paper analyses five indexing models and proposes expectation of traversed service count to estimate performance of service retrieval. Based on these expectation formulas, an optimal deployment method can be identified to maximize efficiency of service retrieval. Our experiments first validate correctness of the proposed formulas and then validate the effective of the optimal method.