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arXiv 2023年

作者： Desyatkin, Victor G. Martin, William B. Aliev, Ali E. Chapman, Nathaniel E. Fonseca, Alexandre F. Galvão, Douglas S. Miller, E. Roy Stone, Kevin H. Wang, Zhong Zakhidov, Dante Limpoco, F. Ted Almahdali, Sarah R. Parker, Shane M. Baughman, Ray H. Rodionov, Valentin O. Department of Macromolecular Science and Engineering Case Western Reserve University 2100 Adelbert Road ClevelandOH44106 United States Alan G. MacDiarmid NanoTech Institute University of Texas at Dallas 800 West Campbell Road RichardsonTX75080 United States Applied Physics Department Institute of Physics "Gleb Wataghin" University of Campinas SP Campinas13083-970 Brazil Department of Chemistry Case Western Reserve University 10900 Euclid Ave ClevelandOH44106 United States Stanford Synchrotron Radiation Lightsource SLAC National Accelerator Laboratory 2575 Sand Hill Road Menlo ParkCA94025 United States Department of Materials Science and Engineering Stanford University 496 Lomita Mall StanfordCA94305 United States Oxford Instruments Asylum Research 6310 Hollister Ave Santa BarbaraCA93117 United States

γ-Graphyne is the most symmetric sp2/sp1 allotrope of carbon, which can be viewed as graphene uniformly expanded through insertion of two-carbon acetylenic units between all the aromatic rings. To date, synthesis of bulk γ-graphyne has remained a challenge. We here report the synthesis of multilayer γ-graphyne through crystallization-assisted irreversible cross-coupling polymerization. Comprehensive characterization of this new carbon phase is described, including synchrotron X-ray diffraction, electron diffraction, lateral force microscopy, Raman and infrared spectroscopy, and cyclic voltammetry. Experiments indicate that γ-graphyne is a 0.48 eV bandgap semiconductor, with a hexagonal a-axis spacing of 6.88 Å and an interlayer spacing of 3.48 Å, which is consistent with theoretical predictions. The observed crystal structure has an aperiodic sheet stacking. The material is thermally stable up to 240 °C but undergoes a transformation at higher temperatures. While conventional 2D polymerizations and reticular chemistry rely on error correction through reversibility, we demonstrate that a periodic covalent lattice can be synthesized under purely kinetic control. The reported methodology is scalable and inspires extension to other allotropes of the graphyne family. © 2023, CC BY-NC-ND.

关键词： Carbon

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Disorder-driven glasslike thermal conductivity in colusite Cu26V2Sn6S32 investigated by Mössbauer spectroscopy and inelastic neutron scattering

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Physical Review materials 2020年第2期4卷 025404-025404页

作者： Christophe Candolfi Gabin Guélou Cédric Bourgès Andrew R. Supka Rabih Al Rahal Al Orabi Marco Fornari Bernard Malaman Gérard Le Caër Pierric Lemoine Vincent Hardy Jean-Marc Zanotti Raju Chetty Michihiro Ohta Koichiro Suekuni Emmanuel Guilmeau Institut Jean Lamour UMR 7198 CNRS – Université de Lorraine 2 allée André Guinier-Campus ARTEM BP 50840 54011 Nancy Cedex France Laboratoire CRISMAT UMR 6508 CNRS ENSICAEN 6 Boulevard du Maréchal Juin 14050 Caen Cedex 04 France Department of Physics and Science of Advanced Materials Program Central Michigan University Mt. Pleasant Michigan 48859 United States Solvay Design and Development of Functional Materials Department AXEL’ ONE Collaborative Platform − Innovative Materials 87 Rue des Freres Perret − BP62 69192 Saint Fons Cedex France Institut de Physique de Rennes UMR UR1-CNRS 6251 Université de Rennes I Campus de Beaulieu 35042 Rennes Cedex France Université de Rennes CNRS ISCR – UMR 6226 F-35000 Rennes France Laboratoire Léon Brillouin CNRS-CEA (UMR 12) CNRS Université Paris-Saclay CEA Saclay 91191 Gif-sur-Yvette Cedex France Research Institute for Energy Conservation National Institute of Advanced Industrial Science and Technology (AIST) Tsukuba Ibaraki 305–8568 Japan Department of Applied Science for Electronics and Materials Interdisciplinary Graduate School of Engineering Sciences Kyushu University Kasuga Fukuoka 816–8580 Japan

The influence of structural disorder on the thermal transport in the colusite Cu26V2Sn6S32 has been investigated by means of low-temperature thermal conductivity and specific heat measurements (2–300 K), Sn119 Mössbauer spectroscopy and temperature-dependent powder inelastic neutron scattering (INS). Variations in the high-temperature synthesis conditions act as a key parameter for tuning the degree of disorder in colusite compounds. Intriguingly, we find that all synthesized samples are disordered, the degree of which varies with the synthesis conditions used. Mössbauer data clearly evidence that Sn atoms do not solely occupy the 6c site of the crystal lattice but are present on possibly both the Cu and V sites, leading to a random distribution of these three cations within the unit cell. Increasing the disorder in these materials tends to lead to a smearing out of the main features in the phonon density of states measured by INS. Although the evolution of the inelastic signal upon warming is well described by a quasiharmonic approximation, elastic properties calculations indicate large average Grüneisen parameters, consistent with those determined experimentally from thermodynamic data. Increasing the level of disorder results in a decreased average Grüneisen parameter suggesting that the lowered lattice thermal conductivity is not driven by enhanced anharmonicity. These results provide experimental evidence to support that the remarkable changeover in the lattice thermal conductivity from crystalline to glasslike is solely driven by enhanced disorder accompanied by local lattice distortions.

关键词： Thermal properties Polycrystalline materials Mössbauer spectroscopy Time-of-flight neutron spectroscopy

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Periodic dynamics, localization metastability, and elastic interaction of colloidal particles with confining surfaces and helicoidal structure of cholesteric liquid crystals

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Physical Review E 2014年第6期90卷 062502-062502页

作者： Michael C. M. Varney Qiaoxuan Zhang Mykola Tasinkevych Nuno M. Silvestre Kris A. Bertness Ivan I. Smalyukh Department of Physics University of Colorado at Boulder Boulder Colorado 80309 USA Materials Science and Engineering Program University of Colorado at Boulder Boulder Colorado 80309 USA Max-Planck-Institut für Intelligente Systeme D-70569 Stuttgart Germany Institut für Theoretische Physik IV Universität Stuttgart D-70569 Stuttgart Germany Centro de Física Teórica e Computacional and Faculdade de Ciências da Universidade de Lisboa Av. Prof. Gama Pinto 2 1649-003 Lisboa Portugal National Institute of Standards and Technology Boulder Colorado 80305 USA Department of Electrical Computer and Energy Engineering and Liquid Crystals Materials Research Center University of Colorado at Boulder Boulder Colorado 80309 USA Renewable and Sustainable Energy Institute National Renewable Energy Laboratory and University of Colorado at Boulder Boulder Colorado 80309 USA

Nematic and cholesteric liquid crystals are three-dimensional fluids that possess long-range orientational ordering and can support both topological defects and chiral superstructures. Implications of this ordering remain unexplored even for simple dynamic processes such as the ones found in so-called “fall experiments,” or motion of a spherical inclusion under the effects of gravity. Here we show that elastic and surface anchoring interactions prompt periodic dynamics of colloidal microparticles in confined cholesterics when gravity acts along the helical axis. We explore elastic interactions between colloidal microparticles and confining surfaces as well as with an aligned ground-state helical structure of cholesterics for different sizes of spheres relative to the cholesteric pitch, demonstrating unexpected departures from Stokes-like behavior at very low Reynolds numbers. We characterize metastable localization of microspheres under the effects of elastic and surface anchoring periodic potential landscapes seen by moving spheres, demonstrating the important roles played by anchoring memory, confinement, and topological defect transformation. These experimental findings are consistent with the results of numerical modeling performed through minimizing the total free energy due to colloidal inclusions at different locations along the helical axis and with respect to the confining substrates. A potential application emerging from this work is colloidal sorting based on particle shapes and sizes.

关键词： CHOLESTERIC liquid crystals LIQUID crystals ENANTIOSELECTIVE catalysis HELICAL waveguides GRAVITY

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Effect of Temperature and Mischmetal Addition on the Microstructure, Mechanical Andcorrosion Behavior of Crn Hard Coatings Deposited Onto Zk60 Magnesium Alloys Using Hipims

SSRN

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SSRN 2023年

作者： Pereira da Silva, Erenilton Oliveira Junior, William Tavares Avila, Pedro Renato Lima Ribeiro, Josy Kelly Alves dos Santos, Marcos Junio Cortez Maciel, Natalia Mendes Rodrigues, Alisson Pinto, Haroldo Cavalcanti MG Janaúba39447-790 Brazil Department of Engineering Physics Polytechnique Montréal P.O. Box 6079 Station Centre-Ville MontréalQCH3C 3A7 Canada Graduate Program in Materials Science UnB Planaltina Faculty University of Brasilia DF Brasilia70904-910 Brazil SP São Carlos13566-590 Brazil

Magnesium alloys have recently gained popularity due to their low density and suitability for various applications requiring both lightweight and robust mechanical qualities. Nevertheless, their widespread utilization could be improved by their inadequate corrosion resistance. This study examines the deposition of ceramic films using chromium nitride (CrN) via High Power Impulse Magnetron Sputtering (HiPIMS) on ZK60 and ZK60 + 1.5 Mischmetal (MM) at 200°C and 300°C. The morphology and thickness of the CrN films was evaluated by Field Emission Gun-Scanning Electron Microscopy (FEG-SEM) and X-ray Diffraction (XRD), roughness by atomic force microscopy (AFM), and mechanical properties (hardness and elastic modulus) were measured by nanoindentation experiments. Furthermore, the electrochemical impedance spectroscopy (EIS) analysis was used to evaluate the corrosion resistance. Fractured cross-section SEM-FEG images of CrN coatings deposited at 200°C and 300°C revealed differences in thickness and morphology for all samples. ZK60 samples exhibited thicker coatings compared to ZK60+1.5MM, which can be attributed to the stability of intermetallic phases. Increasing temperature resulted in the formation of thinner coatings. Also, at 300°C samples presented different thickness. Surface roughness decreases with temperature, reflecting the formation of refined columnar structures. Hardness and elastic modulus increased with temperature, also presenting different behaviors at 300°C. Corrosion resistance also presented improvement at higher temperatures, with ZK60 outperforming ZK60+1.5MM, as EIS analysis confirmed the denser films enhance corrosion protection, while porous coatings exhibit lower resistance, as was observed for ZK60+1.5MM at 300°C. Results also showed the impact of the thermic stability of the samples on the coating formation, indicating that substrate temperature rises during deposition, leading to possible phase changes in the substrate and, consequently, affe

关键词： Corrosion resistance

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Solar‐Powered Redox Cells: Efficient Solar Energy Harvesting and Storage through a Robust Photocatalyst Driving Reversible Redox Reactions (Adv. Mater. 31/2018)

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Advanced materials 2018年第31期30卷

作者： Yangen Zhou Shun Zhang Yu Ding Leyuan Zhang Changkun Zhang Xiaohong Zhang Yu Zhao Guihua Yu Institute of Functional Nano & Soft Materials (FUNSOM) Jiangsu Key Laboratory for Carbon‐Based Functional Materials & Devices Soochow University Suzhou Jiangsu 215123 China Materials Science and Engineering Program and Department of Mechanical Engineering The University of Texas at Austin Austin TX 78712 USA

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Gain-narrowed emissions of thiophene/phenylene co-oligomer single crystals

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physica status solidi c 2008年第1期6卷

作者： Toru Hiramatsu Naoki Matsuoka Hisao Yanagi Fumio Sasaki Shu Hotta Graduate School of Materials Science Nara Institute of Science and Technology Ikoma Nara 630-0192 Japan Photonics Research Institute National Institute of Advanced Industrial Science and Technology Tsukuba Ibaraki 305-8568 Japan Department of Macromolecular Science and Engineering Graduate School of Science and Technology Kyoto Institute of Technology Matsugasaki Sakyo-ku Kyoto 606-8585 Japan

In order to elucidate the origin of gain-narrowed photoluminescence spectra of 5,5″-bis(4-biphenylyl)-2,2′:5′,2″-terthiophene (BP3T) single crystals, the dependence of excitation energy threshold on excitation lengths was studied at 12 K. The emission peak of the 0-1 vibrational band was narrowed at a constant excitation density irrespective of the excitation length, indicating that the gain-narrowing followed a stimulated emission process. On the other hand, the excitation density threshold for the 0-2 peak decreased with increasing excitation length. The latter behaviour is suggestive of a cooperative interaction among uniaxially oriented transition dipoles in the BP3T crystal. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

关键词： 42.70.Jk 78.45.+h 78.55.Kz

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Plasmonic Metasurfaces: Tunable Graphene Metasurfaces with Gradient Features by Self-Assembly-Based Moiré Nanosphere Lithography (Advanced Optical materials 12/2016)

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Advanced Optical materials 2016年第12期4卷

作者： Zilong Wu Wei Li Maruthi Nagavalli Yogeesh Seungyong Jung Alvin Lynghi Lee Kyle McNicholas Andrew Briggs Seth R. Bank Mikhail A. Belkin Deji Akinwande Yuebing Zheng Department of Mechanical Engineering Materials Science and Engineering Program and Texas Materials Institute The University of Texas at Austin Austin TX 78712 USA Microelectronics Research Centre The University of Texas at Austin Austin TX 78758 USA Department of Electrical and Computer Engineering The University of Texas at Austin Austin TX 78712 USA

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Carbon Nanofibers: Bionanofiber Assisted Decoration of Few-Layered MoSe2Nanosheets on 3D Conductive Networks for Efficient Hydrogen Evolution (Small 7/2017)

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Small 2017年第7期13卷

作者： Feili Lai Dingyu Yong Xueliang Ning Bicai Pan Yue-E Miao Tianxi Liu State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular Science Fudan University Shanghai 200433 P. R. China Hefei National Laboratory for Physical Science at Microscale Collaborative Innovation Center of Chemistry for Energy Materials University of Science and Technology of China Hefei 230026 P. R. China State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and Engineering Donghua University Shanghai 201620 P. R. China

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Breaking the Passivity Wall of Metals: Exempli Gratia Non-Aqueous Ti–Air Battery

SSRN

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SSRN 2022年

作者： Durmus, Yasin Emre Kaltenberg, Marcel Dzieciol, Krzysztof Schalenbach, Maximilian Gelman, Danny Shvartsev, Boris Tempel, Hermann Kungl, Hans Eichel, Rüdiger-A Ein-Eli, Yair Forschungszentrum Jülich GmbH Jülich52428 Germany Grand Technion Energy Program Technion – Israel Institute of Technology Haifa3200003 Israel Department of Materials Science and Engineering Technion Israel Institute of Technology Haifa3200003 Israel Institut für Materialien und Prozesse für elektrochemische Energiespeicher– und wandler RWTH Aachen University Aachen52074 Germany Research Centre Jülich Germany

A new multivalent metal–air battery employing Titanium (Ti) as active material in EMIm(HF)2.3F room temperature ionic liquid electrolyte is introduced. Ti metal is highly attractive as it is a light metal that can possibly transfer up to 4 electrons. The electrochemical behavior of Ti is known for its passivity in various media. Here, we evaluated the electrochemistry of Ti in EMIm(HF)2.3F with potentiodynamic polarization and galvanostatic discharge experiments. Ti–air battery could successfully be operated under relatively high current densities (up to 0.75 mA cm−2) with an average cell voltage of 1-1.2 V, yielding up to a discharge capacity of 66 mAh cm−2. When its full potential is harvested, such a metal–battery holds a unique potential to be the only metal with 4 electrons transfer during its discharge. © 2022, The Authors. All rights reserved.

关键词： Titanium

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Development of Flame Retardant Property on Sodium Silicate Treated Paper Based materials

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Journal of Physics: Conference Series 2022年第1期2175卷

作者： Thitiporn Suttipintu Siraprapa Lhosupasirirat Tanakorn Osotchan Toemsak Srikhirin Materials Science and Engineering Program School of Materials Science and Innovation Faculty of Science Mahidol University Bangkok10400 Thailand Research Network of NANOTEC at Mahidol University National Nanotechnology Center Thailand Department of Physics Faculty of Science Mahidol University 272 Rama VI Road Ratchathewi District Bangkok 10400 Thailand

The preparation of cellulose-based flame retardant paper treated with sodium silicate and silicon dioxide (SiO2) colloidal particle by simple immersion process is reported. Cellulose-based paper was preheated at 90°C for surface preparation. The heat treated paper was immersed in solution of sodium silicate-SiO2 at different immersion time ranging from 15 min to 24 hrs. Treated solution diffused into paper coated on the paper fiber and filled the void in the paper microstructure. Treated paper was heated at 90°C to convert an impregnated sodium silicate-SiO2 precursor into silicate framework. The treated paper showed Vsym Si-O-Si from siloxane bond at 792 cm-1 which confirmed a presence of SiO2 in paper. Treated paper at 1 hr immersion showed the highest weight percent gain (WPG) of 40% and total combustion time was improved to 14 sec.

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