bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tunable Control of Interlayer Excitons in WS2/MoS2 Heterostructures via Strong Coupling with Enhanced Mie Resonances
Authors: Yan Jiahao , Ma Churong , Huang Yingcong , Yang Guowei 
Published: April 2019

AbstractStrong Coulomb interactions in monolayer transition metal dichalcogenides (TMDs) produce strongly bound excitons, trions, and biexcitons. The existence of multiexcitonic states has drawn tremendous attention because of its promising applications in quantum information. Combining different monolayer TMDs into van der Waals (vdW) heterostructures opens up opportunities to engineer exciton devices and bring new phenomena. Spatially separated electrons and holes in different layers produce interlayer excitons. Although much progress has been made on excitons in single layers, how interlayer excitons contribute the photoluminescence emission and how to tailor the interlayer exciton emission have not been well understood. Here, room temperature strong coupling between interlayer excitons in the WS2/MoS2 vdW heterostructure and cavity‐enhanced Mie resonances in individual silicon nanoparticles (Si NPs) are demonstrated. The heterostructures are inserted into a Si film‐Si NP all‐dielectric platform to realize effective energy exchanges and Rabi oscillations. Besides mode splitting in scattering, tunable interlayer excitonic emission is also observed. The results make it possible to design TMDs heterostructures with various excitonic states for future photonics devices.
Definition of a Family of Nonmobile Colistin Resistance (NMCR‐1) Determinants Suggests Aquatic Reservoirs for MCR‐4
Authors: Zhang Huimin , Wei Wenhui , Huang Man , Umar Zeeshan , Feng Youjun 
Published: April 2019

AbstractPolymyxins, a family of cationic antimicrobial peptides, are recognized as a last‐resort clinical option used in the treatment of lethal infections with carbapenem‐resistant pathogens. A growing body of mobile colistin resistance (MCR) determinants renders colistin ineffective in the clinical and human sectors, posing a challenge to human health and food security. However, the origin and reservoir of the MCR family enzymes is poorly understood. Herein, a new family of nonmobile colistin resistance (from nmcr‐1 to nmcr‐1.8) from the aquatic bacterium Shewanella is reported. NMCR‐1 (541aa) displays 62.78% identity to MCR‐4. Genetic and structural analyses reveal that NMCR‐1 shares a similar catalytic mechanism and functional motifs, both of which are required for MCR action and its resultant phenotypic resistance to polymyxin. Phylogeny and domain‐swapping demonstrate that NMCR‐1 is a progenitor of MCR‐4 rather than MCR‐1/2. Additionally, the experiment of bacterial growth and viability reveals that NMCR‐1 promotes fitness cost as MCR‐1/4 does in the recipient Escherichia coli. In summary, the finding suggests that the aquatic bacterium Shewanella (and even its associated aquaculture) is a reservoir for MCR‐4 mobile colistin resistance.
Novel Sub‐5 nm Layered Niobium Phosphate Nanosheets for High‐Voltage, Cation‐Intercalation Typed Electrochemical Energy Storage in Wearable Pseudocapacitors
Authors: Wu Zeyi , Jiang Le , Tian Wenchao , Wang Yanan , Jiang Yingchang , Gu Qinfen , Hu Linfeng 
Published: April 2019

AbstractLayered niobium phosphates have been considered very promising energy storage materials because of their high theoretical operating voltage window and the rich oxidation states of niobium. However, their development has been stymied by the phase‐controlled synthesis due to the insolubility of niobium sources except in concentrated hydrofluoric (HF) acid systems. Herein, a new avenue is opened for layered acid niobium phosphate (2NbOPO4·H3PO4·H2O) synthesis in a mild oxalic acid system. Taking advantage of this strategy, in situ growth of sub‐5 nm 2NbOPO4·H3PO4·H2O nanosheet (NPene) arrays on conductive carbon fiber cloth (CFC) substrates is achieved as self‐standing electrodes for solid‐state supercapacitors. Interestingly, the NPene@CFC electrode exhibits a typical cation (H+ or Li+)‐intercalation kinetics with a wide potential window of 0–1.0 V in aqueous electrolytes. Given the wide potential window and highly exposed active surface, the solid‐state asymmetric supercapacitors constructed from such a NPenes@CFC electrode display a high working potential of 2.0 V, energy density of 122.2 W h kg−1 at a power density of 589.7 W kg−1, cycle stability with a capacitance retention of 94.2% after 10 000 cycles, and also outstanding flexible and wearable characteristics.
ortho‐Phenylene‐Bridged Hybrid Nanorings of 2,5‐Pyrrolylenes and 2,5‐Thienylenes
Authors: Chen Fengkun , Kim Jinseok , Matsuo Yusuke , Hong Yongseok , Kim Dongho , Tanaka Takayuki , Osuka Atsuhiro 
Published: April 2019

AbstractHybrid nanorings composed of 2,5‐pyrrolylene, 2,5‐thienylene, and bridging ortho‐phenylene were synthesized by strategic cross‐coupling reactions, and their structures were unambiguously revealed by X‐ray diffraction analysis. These nanorings showed highly twisted structures in the solid‐state, while exhibiting symmetric 1H NMR spectra, indicating their conformational flexibilities in solution. The photophysical and electrochemical properties of these nanorings were studied in detail by UV/Vis and fluorescence spectroscopy, femto‐second laser‐based spectroscopy, and cyclic voltammetry with the aid of DFT calculations. It is shown that hybridization of nanorings with 2,5‐thienylene and 2,5‐pyrrolylene is an effective means to tune their electronic properties.
Galliummethylen
Authors: Bonath Martin , Maichle‐Mössmer Cäcilia , Sirsch Peter , Anwander Reiner 
Published: April 2019

AbstractUngeachtet der herausragenden Bedeutung von Metallalkyliden‐Verbindungen für die organische Synthese und industrielle katalytische Prozesse sind molekulare homoleptische Metallmethylen‐Verbindungen [M(CH2)n] als deren einfachste Vertreter bislang nicht beschrieben worden. Erstmals wurde 1955 berichtet, dass polymeres [Li2(CH2)]n und [Mg(CH2)]n durch Pyrolyse von Methyllithium bzw. Dimethylmagnesium erhalten werden kann. Die unlösliche, salzartige Beschaffenheit dieser Verbindungen erschwerte jedoch die Verwendung als nützliche Reagenzien. Wir berichten nun, dass homoleptisches Galliummethylen [Ga8(μ‐CH2)12] ausgehend von Trimethylgallium [GaMe3] über eine Kaskade von C‐H‐Bindungsaktivierungen erhalten werden kann. Seine Bildung wird durch Seltenerdmetallocen‐Methyl‐Komplexe [(C5Me5)2Ln{(μ‐Me)2GaMe2}] (Ln=Lu, Y) vermittelt, wobei dodekametallische Cluster des Typs [(C5Me5)6Ln3(μ3‐CH2)6Ga9(μ‐CH2)9] als entscheidende Zwischenstufen auftreten. Galliummethylen zeigt eine charakteristische, reversible [Ga8(μ‐CH2)12]/[Ga6(μ‐CH2)9]‐Isomerenumwandlung in Donorlösungsmitteln und erweist sich als Methylen‐Transferreagenz vom Schrock‐Typ.
Gallium Methylene
Authors: Bonath Martin , Maichle‐Mössmer Cäcilia , Sirsch Peter , Anwander Reiner 
Published: April 2019

AbstractDespite the eminent importance of metal alkylidene species for organic synthesis and industrial catalytic processes, molecular homoleptic metal methylene compounds [M(CH2)n] as the simplest representatives, have remained elusive. Reports on this topic date back to 1955 when polymeric [Li2(CH2)]n and [Mg(CH2)]n were accessed by pyrolysis of methyllithium and dimethylmagnesium, respectively. However, the insoluble salt‐like composition of these compounds has impeded their application as valuable reagents. We report that rare‐earth metallocene methyl complexes [(C5Me5)2Ln{(μ‐Me)2GaMe2}] (Ln=Lu, Y) trigger the formation of homoleptic gallium methylene [Ga8(μ‐CH2)12] from trimethylgallium [GaMe3] (Me=methyl) via a cascade C−H bond activation involving the dodecametallic clusters [(C5Me5)6Ln3(μ3‐CH2)6Ga9(μ‐CH2)9] as crucial intermediates. Such gallium methylene compounds feature a reversible [Ga8(μ‐CH2)12]/[Ga6(μ‐CH2)9] oligomer switch in donor solvents and act as Schrock‐type methylene‐transfer reagents.
Molecular cloning, expression profiling, and functional analysis of a broad‐complex isoform 2/3 (Br‐Z2/Z3) transcription factor in the diamondback moth, Plutella xylostella (L.)
Authors: Huang Jingfei , Fang Ling , Wang Shuai , Liu Xiang , Chen Yong , Chen Yixin , Tian Houjun , Lin Shuo , Tian Sufen , Wei Hui , Gu Xiaojun 
Published: April 2019

AbstractThe diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is a widespread and destructive pest of cruciferous crops. New strategies for controlling it are needed because it is rapidly developing resistance to conventional pesticides. In insects, transcription factors (TFs) including broad‐complex (Br‐C) are thought to be useful for insecticide development because they are able to regulate the transcription of functional genes involved in responses to external stimuli including insecticides. In the present study, we cloned and sequenced the open reading frames (ORFs) of three BTB‐ZF encoding genes from the diamondback moth deposited in the National Center for Biotechnology Information (NCBI) database under accessions MG753773, MG288674, and MG753772. The lengths of these ORFs were 1,680, 1,428, and 1,647 bp, respectively. The phylogenetic analysis based on the predicted amino acid sequences of ZF domains showed that MG753773 and MG288674 belonged to Z2/Z3 and Z7 of Br‐C while MG753772 belonged to Ttk types. In the agreement, the highest expression level of MG753773 occurred during the prepupal stage, MG288674 and MG753772 were expressed during all stages and peaked in the adult and egg stages, respectively. RNA interference silencing of MG753773 in the late third instar larvae significantly decreased survival and pupation of the insects. With precocene II, transcription of MG753773 increased (4×) in the fourth instar larva 24 hr later; 48 hr later the rate of prepupation and pupation was significantly higher. These findings will contribute to the development of new regulators of the growth and development for diamondback moth control.
Berechnung der Kühlgestehungskosten von fassadengebundenen Begrünungssystemen im städtischen Raum
Authors: Tudiwer David , Hollands Jutta , Korjenic Azra 
Published: April 2019

AbstractIm vorliegenden Aufsatz wird eine neue Methode zur ökonomischen Bewertung von Bauwerksbegrünung vorgestellt. Aufbauend auf bereits publizierten ökonomischen Analysen wird hier auf eine in diesem Bereich bisher unbeachtete Berechnungsmethode verwiesen, die derzeit meist in der Energiewirtschaft Anwendung findet. In dieser Methode werden die Gestehungskosten ermittelt. Erstmalig werden die Kühlgestehungskosten einer südseitigen begrünten Fassade berechnet. Dabei wirken sich drei voneinander unabhängige Parameter auf die Kühlgestehungskosten aus: die Verdunstungsleistung der begrünten Fassade, die Gesamtkosten für das Begrünungssystem und die Anzahl der Sommertage. Demnach beeinflussen unter anderen die Bauart, die Bepflanzung, die Lebenszykluskosten sowie der Standort der Fassadenbegrünung die Höhe der Kühlgestehungskosten. Das Ergebnis dieser Beispielberechnungen für den Standort Wien zeigt, dass das derartige Kühlen der Umgebung 0,80 €/kWh entzogene Wärmeenergie kostet. Diese Art der Kühlung kann dem Urban Heat Island (UHI)‐Effekt entgegenwirken.
Behaglichkeitsmonitoring – flächendeckend und kostengünstig mit der Sensorstation CoMoS
Authors: Kimmling Mathias , Hoffmann Sabine 
Published: April 2019

AbstractZur Erfassung von thermischen Umgebungsparametern wurde die Behaglichkeitsmessstation CoMoS (engl. Comfort Monitoring Station) entwickelt. Ziel der Entwicklung war ein kostengünstiges System mit gleichzeitig hoher Messgenauigkeit zum flächendeckenden Einsatz in Gebäuden. Diese Vorgabe wurde durch einen Aufbau erzielt, der auf kompakten, integrierten Sensoren für Lufttemperatur, relative Luftfeuchte, mittels Schwarzkugel gemessener Globe‐Temperatur und Luftgeschwindigkeit basiert.Eine individuelle Kalibrierung aller Sensoren bezogen auf ein Referenzgerät ermöglichte eine Minimierung von Messabweichungen und damit eine hohe Vergleichbarkeit einzelner Messstationen untereinander. Dabei zeigten Kalibrier‐ und Vergleichsmessungen sehr gute Ergebnisse für die Messgrößen Lufttemperatur, Luftfeuchte und Globe‐Temperatur, wohingegen die Luftgeschwindigkeit nur mit einer für den Einsatzzweck ausreichenden Genauigkeit erfasst werden kann. In einem Feldtest wurde nach Abschluss der Kalibrierung und Evaluation die Funktionsfähigkeit des Systems unter realen Umgebungsbedingungen belegt. Die aus der Entwicklung hervorgegangenen Ergebnisse wurden über diesen Beitrag hinaus in Form einer detaillierten Aufbauanleitung einschließlich der zugrunde liegenden Programmierung und der Kalibrierfunktionen online veröffentlicht, siehe Living Lab smart.
Octahedral Cu2O@Co(OH)2 Nanocages with Hierarchical Flake‐Like Walls and Yolk‐Shell Structures for Enhanced Electrocatalytic Activity
Authors: Sheng Jiali , Chen Jiahui , Kang Jiahui , Yu Yan , Yan Ning , Fu Xian‐Zhu , Sun Rong , Wong Ching‐Ping 
Published: April 2019

AbstractUnique octahedral yolk‐shell Cu2O@Co(OH)2 nanocages are synthesized by a facile Cu2O self‐templated strategy as efficient glucose oxidation electrocatalysts. Amorphous Co(OH)2 nanoflakes are formed as octahedral shells through coordinating etching conversion from part of Cu2O templates. The un‐etched crystalline Cu2O octahedrons are then remained as cores and voids exist between the cores and shells. The special structure endow these yolk‐shell heterostructure nanocages with abundant active sites, large surface area, and synergistic effect between Cu2O and Co(OH)2. The octahedral yolk‐shell Cu2O@Co(OH)2 nanocages demonstrate superior electrocatalytic activity for glucose oxidation in terms of high sensitivity of 1340 μA cm−2 mM−1, low detection limit of 2 μM, wide linear sensing range, and long‐term stability. This strategy might shed lights on the synthesis of various yolk‐shell heterostructure nanocages with controllable structures and enhanced catalytic performances.
Simple Transformation of Hierarchical Hollow Structures by Reduction of Metal–Organic Frameworks and Their Catalytic Activity in the Oxidation of Benzyl Alcohol
Authors: Ju Suhyun , Yusuf Mohammad , Jang Seongwan , Kang Hyuntae , Kim Soohee , Park Kang Hyun 
Published: April 2019

AbstractMetal–organic framework (MOF)‐based derivatives have been found to be promising heterogeneous catalysts for organic transformations. Herein, hollow‐structure Cu‐MOFs derived by reduction of Cu3(BTC)2 (BTC=1,3,5‐benzenetricarboxylate; denoted as RCB) were prepared by using hydrazine hydrate as a reducing agent under various conditions. The influence of hydrazine hydrate induced the structure of Cu3(BTC)2 and led to dynamic variation in the interior and exterior as well as oxidation states of the Cu ion. The synthesized materials were characterized by SEM, TEM, N2 sorption isotherms, XRD, and XPS. The product of the catalytic reaction was observed by GC‐MS. In addition, the prepared RCBs were found to have excellent catalytic activity and selectivity for benzyl alcohol oxidation when assisted by 2,2,6,6‐tetramethylpiperidine‐1‐oxyl (TEMPO).
The Link between ZSM‐5 Zeolite Crystallization and Mesopore Formation by Leaching
Authors: Li Teng , Ihli Johannes , Wennmacher Julian T. C. , Krumeich Frank , van Bokhoven Jeroen A. 
Published: April 2019

AbstractAcid or base leaching are well‐established tools in the synthesis of mesoporous zeolites. Previous studies suggest an inherent link between the structure‐property relationship of mesoporous zeolites, that is, chemical resistance, pore diameter and distribution, with zeolite synthesis or crystallization conditions. The exact nature and/or origin of this link is currently however, poorly established. Here, we provide evidence how zeolite crystallization conditions influence the leaching behavior and thus structure of mesoporous zeolites. Electron microscopy and in situ small angle X‐ray scattering both confirmed the crystallization of ZSM‐5 to utilize both nanoparticles and oligomers as elemental building blocks. Utilization of these species is highly depended on supersaturation. The precursor solution of decreased water content favored a faster consumption of nanoparticles compared to its oligomers at the early stage of crystallization. Then the addition of oligomers can heal the surface imperfections and thus the resulting zeolite showed a higher resistance against acid leaching. In contrast, within the precursor solution of increased water content the slower consumption of nanoparticles led to crystals with a less robust rim. Defects existed in the rim due to limited healing by oligomers and, as such, mesopores can be created by the following post‐treatment. Precise control over selected crystallization conditions can therefore further aid the design of optimized mesoporous zeolites.
Selective Formation of a Mixed‐Valence State from Linearly Bridged Oligo(aromatic diamines): Drastic Structural Change into a Folded Columnar Stack for Half‐filled Polycations
Authors: Nojo Wataru , Ishigaki Yusuke , Takeda Takashi , Akutagawa Tomoyuki , Suzuki Takanori 
Published: April 2019

AbstractA method to obtain an organic mixed‐valence state with long‐range delocalization is proposed, which enables the selective generation of half‐filled (n/2‐charged) polycations from linearly bridged oligomers with n electron‐donating units. When π‐extended phenylenediamine units are connected by meta‐xylylene‐type spacers, the resulting oligomers adopt non‐folded structures in the neutral state owing to the non‐conjugating and flexible nature of the spacer, whereas the structure shows a drastic change into a one‐dimensional columnar stack upon oxidation to the corresponding half‐filled polycations. Although they are nano‐sized discrete molecules, they can mimic the electronic structure of crystalline organic conductors in a mixed‐valence state. The key for the oligomer design is adoption of the best‐matched spacer that facilitates formation of the singly charged pimer in the dichromophoric system whereas the corresponding doubly charged π‐dimer is disfavored.
Intelligent and semantic threshold schemes for security in cloud computing
Authors: Ogiela Lidia , Snášel Václav 
Published: April 2019

SummaryThis article presents new methods of securing data with particular emphasis on their applications in Cloud Computing. Methods of hiding data dedicated to processes of its security will be illustrated by cryptographic techniques, particularly data splitting protocols. Cryptographic information sharing algorithms are a particularly important type of techniques allowing confidential or secret data to be secured. These algorithms have been enhanced with new classes of solutions, including semantic protocols of secret sharing. The innovation of this solution consists in the presentation of smart data securing algorithms that use techniques of the semantic sharing of secret information. The information subjected to the process of splitting and hiding can take various forms, including that of services. Because of this aspect, namely, the various forms of the secret, and the use of universal information hiding techniques, a particularly important aspect of the solutions presented here is the ability to use them in various areas of data security. One of such areas comprises Cloud Computing, which forms the leading subject of this publication. In this article, the authors describe intelligent cryptography techniques dedicated to security services data. The most important achievement is the introduction of a new class of data encryption protocols, such as semantic threshold schemes.
A parallel tree node splitting criterion for fuzzy decision trees
Authors: Mu Yashuang , Liu Xiaodong , Wang Lidong , Asghar Aamer Bilal 
Published: April 2019

SummaryFuzzy decision trees are one of the most important extensions of decision trees for symbolic knowledge acquisition by fuzzy representation. Many fuzzy decision trees employ fuzzy information gain as a measure to construct the tree node splitting criteria. These criteria play a critical role in the construction of decision trees. However, many of the criteria can only work well on small‐scale or medium‐scale data sets, and cannot directly deal with large‐scale data sets on the account of some limiting factors such as memory capacity, execution time, and data complexity. Parallel computing is one way to overcome these problems; in particular, MapReduce is one mainstream solution of parallel computing. In this paper, we design a parallel tree node splitting criterion (MR‐NSC) based on fuzzy information gain via MapReduce, which is completed equivalent to the traditional unparallel splitting rule. The experimental studies verify the equivalency between the proposed MR‐NSC algorithm and the traditional unparallel way through 22 UCI benchmark data sets. Furthermore, the feasibility and parallelism are also studied on two large‐scale data sets.
Oxygen Vacancy Engineering of Bi24O31Cl10 for Boosted Photocatalytic CO2 Conversion
Authors: Jin Xiaoli , Lv Chade , Zhou Xin , Ye Liqun , Xie Haiquan , Liu Yue , Su Huan , Zhang Biao , Chen Gang 
Published: April 2019

AbstractUnearthing an ideal model to describe the role of defect sites for boosting photocatalytic CO2 reduction is rational and necessary, but it still remains a significant challenge. Herein, oxygen vacancies are introduced on the surface of Bi24O31Cl10 photocatalyst (Bi24O31Cl10‐OV) for fine‐tuning the photocatalytic efficiency. The formation of oxygen vacancies leads to a new donor level near the conduction band minimum, which enables a faster charge transfer and higher carrier density. Moreover, oxygen vacancies can considerably reduce the energy for the formation of COOH* intermediates during CO2 conversion. As a result, the activity of Bi24O31Cl10‐OV for selective photoreduction of CO2 to CO is significantly improved, with a CO generation rate of 0.9 μmol h−1 g−1, which is nearly 4 times higher than that of pristine Bi24O31Cl10. This study reinforces our understanding of defect engineering in Bi‐based photocatalysts and underscores the potential importance of implanting oxygen vacancies as an effective strategy for solar energy conversion.