bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Flexible Triboelectric Nanogenerator Based on Cellulose‐Reinforced MXene Composite Film
Authors: Yang Wei , Chen Huamin , Wu Mingqiang , Sun Zhaoyang , Gao Min , Li Wenjie , Li Chenyu , Yu Hualiang , Zhang Cheng , Xu Yun , Wang Jun 
Published: February 2022

AbstractA flexible triboelectric nanogenerator (TENG) is an indispensable part in future flexible self‐powered system. However, it is still a great challenge to establish a balance among the robust mechanical property, strong triboelectrification effect, and high conductivity of electrode materials. A flexible and enhanced‐performance TENG based on cellulose nanofibrils (CNFs)/transition metal carbides and nitrides (MXene) composite films is developed here for harvesting human movement energy. By introducing CNFs, the mechanical strength, flexibility of the composite film, and sensitive to the temperature change and strain are improved. The effect of CNFs concentration, working force, and frequency on the output performance of TENG is also demonstrated. At the optimized CNFs/MXene ratio of 2/5, the transferred charges and output voltage reach the maximum value of 7.4 nC and 24.9 V, respectively. The maximum instantaneous output power density of the as‐prepared TENG is 1.2 mW m−2. Moreover, a self‐powered flexible display system is demonstrated by integrating the TENG with a flexible alternating current electroluminescence. The flexible TENG based on cellulose nanofibrils‐reinforced MXene composite film is promising as a flexible energy source for self‐powered system.
Role of Pd in the Electrochemical Hydrogenation of Nitrobenzene Using CuPd Electrodes
Authors: Carvajal David , Arcas Ramón , Mesa Camilo A. , Giménez Sixto , Fabregat‐Santiago Francisco , Mas‐Marzá Elena 
Published: February 2022

AbstractInterest in the electrochemical reduction of organic compounds as an alternative to hydrogen electrosynthesis is driven, among other reasons, by the fact that the products obtained in this process may have more economic value than H2. Furthermore, the technique, coupled with renewable sources of electricity, may open the door for large volume green chemical synthesis. In the present article, the electrochemical reduction and hydrogenation of nitrobenzene to aniline at neutral pH is focused upon, using copper electrodes with and without palladium decoration. Both electrodes present good activity, with a decrease in the overpotential for nitrobenzene reduction and the competing hydrogen evolution reaction when Pd is deposited in the surface of the Cu electrode. It is observed that the rate and selectivity of nitrobenzene reduction to aniline improves at high concentrations, obtaining yields close to 70% for 30 × 10−3 m initial concentrations of nitrobenzene when using Pd decorated Cu electrodes. Impedance spectroscopy analysis reveals that the role of Pd in the decorated electrodes is to enhance the production of H* radicals, necessary for the nitrobenzene reduction process. This explains the increase in the selectivity toward aniline production by the incorporation of small amounts of Pd in the surface of the Cu electrode.
Ultrastable Interfacial Contacts Enabling Unimpeded Charge Transfer and Ion Diffusion in Flexible Lithium‐Ion Batteries
Authors: Shi Ying , Wang Zhenxing , Wen Lei , Pei Songfeng , Chen Ke , Li Hucheng , Cheng Hui‐Ming , Li Feng 
Published: February 2022

AbstractDeteriorating interfacial contact under mechanical deformation induces large cracks and high charge transfer resistance, resulting in a severe capacity fading of flexible lithium‐ion batteries (LIBs). Herein, an oxygen plasma treatment on a polymer separator combined with high‐speed centrifugal spraying to construct ultrastable interfacial contacts is reported. With the treatment, abundant hydrophilic oxygen‐containing functional groups are produced and ensure strong chemical adhesion between the separator and the active materials. With single walled carbon nanotubes (SWCNTs) sprayed onto the active materials, a dense thin film is formed as the current collector. Meanwhile, the centrifugal force caused by high‐speed rotation together with van der Waals forces under fast evaporation produces a much closer interface between the current collector and the active materials. As a result of this ultrastable interfacial interaction, the integrated electrode shows no structural failure after 5000 bending cycles with the charge‐transfer resistance as low as 35.8% and a Li‐ion diffusion coefficient nearly 19 times of the untreated electrode. Flexible LIBs assembled with these integrated electrodes show excellent structural and electrochemical stability, and can work steadily under various deformed states and repeated bending. This work provides a new technique toward rational design of electrode configuration for flexible LIBs.
Futures–spot price transmission in EU corn markets
Authors: Penone Carlotta , Giampietri Elisa , Trestini Samuele 
Published: February 2022

AbstractPrice transmission between futures and spot prices is a relevant issue, dealing with derivatives exchange for price management practices and efficient price discovery. Indeed, due to the increased market orientation of the Common Agricultural Policy, the development of new market strategies is of utmost importance for European farmers. In this context, this study examines the degree of transmission for the corn commodity between global futures price in either the Chicago Board of Trade or Euronext and the spot prices for a selection of Member States of the European Union. This study provides critical insights into the shape of the futures–spot price transmission, confirming a long‐run relationship and a cointegrating behaviour of price sets. [EconLit Citations: Q02, Q14, E3].
Experiments on floating bed rotating drums using magnetic particle tracking
Authors: Nijssen Tim M. J. , van Dijk Mark A. H. , Kuipers Hans A. M. , van der Stel Jan , Adema Allert T. , Buist Kay A. 
Published: February 2022

AbstractMagnetic particle tracking (MPT) was employed to study a rotating drum filled with cork particles, using both air and water as interstitial medium. This noninvasive monitoring technique allows for the tracking of both particle translation and rotation in dry granular and liquid–solid systems. Measurements on the dry and floating bed rotating drum were compared and detailed analysis of the bed shape and velocity profiles was performed. It was found that the change of particle–wall and particle–particle interaction caused by the presence of water significantly affects the bed behavior. The decreased friction leads to slipping of the particles with respect to the wall, rendering the circulation rate largely insensitive to increased drum speed. It was also found that the liquid–particle interaction is determining for the behavior of the flowing layer. The well‐defined experiments and in‐depth characterization performed in this study provide an excellent validation case for multiphase flow models.
Spin Dynamics of Moving Bodies in Rotating Black Hole Spacetimes
Authors: Mikóczi Balázs , Keresztes Zoltán 
Published: February 2022

AbstractThe dynamics of spinning test bodies, moving in rotating black hole (Kerr, Bardeen‐like and Hayward‐like) spacetimes, are investigated. In Kerr spacetime, all the spherical, zoom‐whirl and unbound orbits are considered numerically. Along spherical orbits and for high spin, an amplitude modulation is found in the harmonic evolution of the spin precessional angular velocity, caused by the spin‐curvature coupling. Along the discussed zoom‐whirl and unbound orbits, the test body approaches the center so much that it passes through the ergosphere. Near and inside the ergosphere, the variation of the spin direction can be very rapid. The effects of the spin‐curvature coupling is also investigated. The initial values are chosen such a way, that the body and its spin move in the equatorial plane of the coordinate space and of the comoving frame, respectively. Hence, a clear effect of the spin‐curvature coupling is observed as the orbit and the spin vector leave the equatorial plane. Additional effects in the spin precessional angular velocity and in the evolution of the Boyer–Lindquist coordinate components of the spin vector is also considered. Finally, in case of different regular black holes, the spin‐curvature coupling influences differently the orbit and the spin evolutions.
Switchable Polymerization Organocatalysis: From Monomer Mixtures to Block Copolymers
Authors: Tang Jiadong , Li Maosheng , Wang Xianhong , Tao Youhua 
Published: February 2022

AbstractOne‐pot production of sequence‐controlled block copolymer from mixed monomers is a crucial but rarely reached goal. Using a switchable Lewis‐pair organocatalyst, we have accomplished sequence‐selective polymerization from a mixture ofO‐carboxyanhydride (OCA) and epoxide. Polymerization of the OCA monomer occurs first and exclusively because of its exceedingly high polymerizability. When OCA is fully consumed, alternating copolymerization of epoxide and CO2liberated in OCA polymerization is triggered from the termini of the first block. The two polymerizations thus occur in tandem, both in chemoselective fashion, so that a sequence‐controlled block polymer with up to 99 % CO2conversion is furnished in this one‐pot protocol. Calculations and experimental results demonstrate a chemoselective and cooperative mechanism, where the high polymerizability of the OCA monomers guarantees exquisite sequence selectivity and the cooperative decarboxylation partly arose from the stabilization effect by triethylborane, which facilitates the smooth transformation of the chain end from carbonate to alkoxide.
Self‐Evolution of High Mechanical Strength Dry‐Network Polythiourethane Thermosets into Neat Macroscopic Hollow Structures
Authors: Zhou Shang‐Wu , Tong Fei , Chen Meng , Gu Ruirui , Shi Chen‐Yu , Yu Cheng‐Yuan , Zhang Qi , Qu Da‐Hui 
Published: February 2022

AbstractOrganism‐inspired hollow structures are attracting increasing interest for the construction of various bionic functional hollow materials. Next‐generation self‐evolution hollow materials tend to combine simple synthesis, high mechanical strength, and regular shape. In this study, we designed and synthesized a novel dry‐network polythiourethane thermoset with excellent mechanical performance. The polymer film could evolve into a neat and well‐organized object with a macroscopic hollow interior structure after being immersed in an aqueous NaOH solution. The self‐evolution hollow structure originated from a hydrogen‐bonded polymer network, which was later transformed into a network bearing both hydrogen bonds and ionic bonds. The swelling and thickness growth of this material could be controlled by the NaOH concentration and the immersion time. This unique self‐evolution behavior was further utilized to produce a series of macroscopic 3D hollow‐containing molds, which could be potentially applied in the production of smart materials.
Ein stark fluoreszierender zweikerniger Aluminiumkomplex mit nahezu 100 %iger Quantenausbeute**
Authors: Portwich Flavio L. , Carstensen Yves , Dasgupta Anindita , Kupfer Stephan , Wyrwa Ralf , Görls Helmar , Eggeling Christian , Dietzek Benjamin , Gräfe Stefanie , Wächtler Maria , Kretschmer Robert 
Published: February 2022

AbstractAufgrund der hohen natürlichen Häufigkeit von Aluminium sind die entsprechenden Fluorophore für verschiedene optische Anwendungen attraktiv, jedoch wurden bislang keine Photolumineszenz‐Quantenausbeuten über 0.7 für Lösungen von Aluminiumkomplexen beschrieben. In diesem Beitrag beschreiben wir einen zweikernigen Aluminium(III)‐Komplex, der verbesserte Photolumineszenzeigenschaften aufweist und dessen einfache Synthese von einem gut verfügbaren Protio‐Liganden und Trimethylaluminium ausgeht. In Lösung zeigt der Komplex eine bislang nicht beschriebene Photolumineszenz‐Quantenausbeute nahe 100 % (Φabsolut 1.0±0.1), und der angeregte Zustand weist eine Lebensdauer von 2.3 ns auf. Im festen Zustand kommt es zu J‐Aggregation und aggregations‐bedingter Löschung, aber es können noch immer Quantenausbeuten von 0.6 beobachtet werden. Die Einbettung des Komplexes in elektrogesponnene Fasern führt zu einem stark fluoreszierenden Vlies mit einer Quantenausbeute von 0.9±0.04.
Encoding Enantiomeric Molecular Chiralities on Graphene Basal Planes
Authors: Meng Yongqiang , Fan Jingbiao , Wang Meihui , Gong Wenbin , Zhang Jinping , Ma Junpeng , Mi Hongyu , Huang Yan , Yang Shu , Ruoff Rodney S. , Geng Jianxin 
Published: February 2022

AbstractGraphene has demonstrated broad applications due to its prominent properties. Its molecular structure makes graphene achiral. Here, we propose a direct way to prepare chiral graphene by transferring chiral structural conformation from chiral conjugated amino acids onto graphene basal plane through π–π interaction followed by thermal fusion. Using atomic resolution transmission electron microscopy, we estimated an areal coverage of the molecular imprints (chiral regions) up to 64 % on the basal plane of graphene (grown by chemical vapor deposition). The high concentration of molecular imprints in their single layer points to a close packing of the deposited amino acid molecules prior to “thermal fusion”. Such “molecular chirality‐encoded graphene” was tested as an electrode in electrochemical enantioselective recognition. The chirality‐encoded graphene might find use for other chirality‐related studies and the encoding procedure might be extended to other two‐dimensional materials.
Regulation of High Miscibility for Efficient Charge‐Transport in n‐Doped Conjugated Polymers
Authors: Li Qi‐Yi , Yao Ze‐Fan , Wu Hao‐Tian , Luo Longfei , Ding Yi‐Fan , Yang Chi‐Yuan , Wang Xin‐Yi , Shen Zhihao , Wang Jie‐Yu , Pei Jian 
Published: February 2022

AbstractStrong interchain interactions of conjugated polymers usually result in poor miscibility with molecular dopants, limiting the doping efficiency because of uncontrolled phase separation. We have developed a strategy to achieve efficient charge‐transport and high doping miscibility in n‐doped conjugated polymers. We solve the miscibility issue through disorder side‐chains containing dopants better. Systemic structural characterization reveals a farther side‐chain branching point will lead to higher disorders, which provides appropriate sites to accommodate extrinsic molecular dopants without harming original chain packings and charge‐transport channels. Therefore, better sustainability of solid‐state microstructure is obtained, yielding a stable conductivity even when overloading massive dopants. This work highlights the importance of realizing high host‐dopant miscibility in molecular doping of conjugated polymers.
A Descriptor for Accurate Predictions of Host Molecules Enabling Ultralong Room‐Temperature Phosphorescence in Guest Emitters
Authors: Chanmungkalakul Supphachok , Wang Chao , Miao Rong , Chi Weijie , Tan Davin , Qiao Qinglong , Ang Esther Cai Xia , Tan Choon‐Hong , Fang Yu , Xu Zhaochao , Liu Xiaogang 
Published: February 2022

AbstractAlthough doping can induce room‐temperature phosphorescence (RTP) in heavy‐atom free organic systems, it is often challenging to match the host and guest components to achieve efficient intersystem crossing for activating RTP. In this work, we developed a simple descriptor ΔE to predict host molecules for matching the guest RTP emitters, based on the intersystem crossing via higher excited states (ISCHES) mechanism. This descriptor successfully predicted five commercially available host components to pair with naphthalimide (NA) and naphtho[2,3‐c]furan‐1,3‐dione (2,3‐NA) emitters with a high accuracy of 83 %. The yielded pairs exhibited bright yellow and green RTP with the quantum efficiency up to 0.4 and lifetime up to 1.67 s, respectively. Using these RTP pairs, we successfully achieved multi‐layer message encryption. The ΔE descriptor could provide an efficient way for developing doping‐induced RTP materials.
Pure Boric Acid Does Not Show Room‐Temperature Phosphorescence (RTP)
Authors: Wu Zhu , Roldao Juan Carlos , Rauch Florian , Friedrich Alexandra , Ferger Matthias , Würthner Frank , Gierschner Johannes , Marder Todd B. 
Published: February 2022

AbstractBoric acid (BA) has been used as a transparent glass matrix for optical materials for over 100 years. However, recently, apparent room‐temperature phosphorescence (RTP) from BA (crystalline and powder states) was reported (Zheng et al., Angew. Chem. Int. Ed. 2021, 60, 9500) when irradiated at 280 nm under ambient conditions. We suspected that RTP from their BA sample was induced by an unidentified impurity. Our experimental results show that pure BA synthesized from B(OMe)3 does not luminesce in the solid state when irradiated at 250–400 nm, while commercial BA indeed (faintly) luminesces. Our theoretical calculations show that neither individual BA molecules nor aggregates would absorb light at >175 nm, and we observe no absorption of solid pure BA experimentally at >200 nm. Therefore, it is not possible for pure BA to be excited at >250 nm even in the solid state. Thus, pure BA does not display RTP, whereas trace impurities can induce RTP.
Emissive Platinum(II) Macrocycles as Tunable Cascade Energy Transfer Scaffolds
Authors: Acharyya Koushik , Bhattacharyya Soumalya , Lu Shuai , Sun Yan , Mukherjee Partha Sarathi , Stang Peter J. 
Published: February 2022

AbstractDeveloping artificial light‐harvesting scaffolds with a cascade energy transfer process is significant for better understanding of photosynthesis. Here, we report [3+3] self‐assembled PtII fluorescent macrocycles (3 a and 3 b) as light‐harvesting platforms with cascade energy transfer. The PtII macrocycles aggregate into nanospheres and show emission‐enhancement characteristics upon increasing water content in acetone medium. These aggregates (3aa and 3ba) serve as energy donors when mixed with the hydrophobic dye Eosin‐Y (ESY). In the presence of a second dye, Nile Red (NiR), an unusual sequential two‐step energy transfer takes place from the macrocycles to NiR. In this case, ESY acts as a bridge in the relay mode. Additionally, a unique strategy to control such an energy transfer process by tuning the chain length of the alkyl group attached to the periphery of the macrocycles is demonstrated.
Structural Basis for Chaperone‐Independent Ubiquitination of Tau Protein by Its E3 Ligase CHIP
Authors: Munari Francesca , Mollica Luca , Valente Carlo , Parolini Francesca , Kachoie Elham Ataie , Arrigoni Giorgio , D'Onofrio Mariapina , Capaldi Stefano , Assfalg Michael 
Published: February 2022

AbstractThe multi‐site ubiquitination of Tau protein found in Alzheimer's disease filaments hints at the failed attempt of neurons to remove early toxic species. The ubiquitin‐dependent degradation of Tau is regulated in vivo by the E3 ligase CHIP, a quality controller of the cell proteome dedicated to target misfolded proteins for degradation. In our study, by using site‐resolved NMR, biochemical and computational methods, we elucidate the structural determinants underlying the molecular recognition between the ligase and its intrinsically disordered substrate. We reveal a multi‐domain dynamic interaction that explains how CHIP can direct ubiquitination of Tau at multiple sites even in the absence of chaperones, including its typical partner Hsp70/Hsc70. Our findings thus provide mechanistic insight into the chaperone‐independent engagement of a disordered protein by its E3 ligase.
A Polymeric Nanobeacon for Monitoring the Fluctuation of Hydrogen Polysulfides during Fertilization and Embryonic Development
Authors: Zhou Yibo , Gu Zhengxuan , Liu Changhui , Yang Sheng , Ma Xiaofei , Chen Qiaoshu , Lei Yanli , Quan Ke , Liu Juewen , Qing Zhihe , Yang Ronghua 
Published: February 2022

AbstractFertilization and early embryonic development as the beginning of a new life are key biological events. Hydrogen polysulfide (H2Sn) plays important roles during physiological regulation, such as antioxidation‐protection. However, no report has studied in situ H2Sn fluctuation during early embryonic development because of the low abundance of H2Sn and inadequate sensitivity of probes. We herein construct a polymeric nanobeacon from a H2Sn‐responsive polymer and fluorophores, which is capable of detecting H2Sn selectively and of signal amplification. Taking the zebrafish as a model, the polymeric nanobeacon revealed that the H2Sn level was significantly elevated after fertilization due to the activation of cell multiplication, suppressed partially during embryonic development, and finally kept steady up to zebrafish emergence. This strategy is generally accessible for biomarkers by altering the responsive unit and significant for facilitating biological analysis during life development.
Haptotropism in a Nickel Complex with a Neutral, π‐Bridging cyclo‐P4 Ligand Analogous to Cyclobutadiene
Authors: Gendy Chris , Valjus Juuso , Tuononen Heikki M. , Roesler Roland 
Published: February 2022

AbstractDedicated to Professor Manfred Scheer on the occasion of his 65th birthdayThe reaction of (1)Ni(η2‐cod), 2, incorporating a chelating bis(N‐heterocyclic carbene) 1, with P4 in pentane yielded the dinuclear complex [(2)Ni]2(μ2,η2 : η2‐P4), 3, formally featuring a cyclobutadiene‐like, neutral, rectangular, π‐bridging P4‐ring. In toluene, the butterfly‐shaped complex [(1)Ni]2(μ2,η2 : η2‐P2), 4, with a formally neutral P2‐unit was obtained from 2 and either P4 or 3. Computational studies showed that a haptotropic rearrangement involving two isomers of the μ2,η2 : η2‐P4 coordination mode and a low‐energy μ2,η4 : η4‐P4 coordination mode, as previously predicted for related nickel cyclobutadiene complexes, could explain the coalescence observed in the low‐temperature NMR spectra of 3. The insertion of the (1)Ni fragment into a P−P bond of P7(SiMe3)3, forming complex 5 with a norbornane‐like P7 ligand, was also observed.
Oxidative Additions of C−F Bonds to the Silanide Anion [Si(C2F5)3]−
Authors: Tiessen Natalia , Keßler Mira , Neumann Beate , Stammler Hans‐Georg , Hoge Berthold 
Published: February 2022

AbstractCompounds exhibiting main group elements in low oxidation states were found to mimic the reactivity of transition metal complexes. Like the latter, such main group species show a proclivity of changing their oxidation state as well as their coordination number by +2, therefore fulfilling the requirements for oxidative additions. Prominent examples of such main group compounds that undergo oxidative additions with organohalides R−X (R=alkyl, aryl, X=F, Cl, Br, I) are carbenes and their higher congeners. Aluminyl anions, which like carbenes and silylenes oxidatively add to strong σ‐bonds in R−X species, have been recently discovered. We present the first anion based upon a Group 14 element, namely the tris(pentafluoroethyl)silanide anion, [Si(C2F5)3]−, which is capable of oxidative additions towards C−F bonds. This enables the isolation of non‐chelated tetraorganofluorosilicate salts, which to the best of our knowledge had only been observed as reactive intermediates before.
Widefield SERS for High‐Throughput Nanoparticle Screening
Authors: Liebel Matz , Calderon Irene , Pazos‐Perez Nicolas , van Hulst Niek F. , Alvarez‐Puebla Ramon A. 
Published: February 2022

AbstractSurface‐enhanced Raman scattering (SERS) imaging is a powerful technology with unprecedent potential for ultrasensitive chemical analysis. Point‐by‐point scanning and often excessively long spectral acquisition‐times hamper the broad exploitation of the full analytical potential of SERS. Here, we introduce large‐scale SERS particle screening (LSSPS), a multiplexed widefield screening approach to particle characterization, which is 500–1000 times faster than typical confocal Raman implementations. Beyond its higher throughput, LSSPS simultaneously quantifies both the sample's Raman and Rayleigh scattering to directly quantify the fraction of SERS‐active particles which allows for an unprecedented correlation of SERS activity with particle size. .