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On-surface activation of benzylic C-H bonds for the synthesis of pentagon-fused graphene nanoribbons

Nano Research 2021年第12期14卷 4754-4759页

作者： Xiushang Xu Marco Di Giovannantonio José I.Urgel Carlo A.Pignedoli Pascal Ruffieux Klaus Müllen Roman Fasel akimitsu narita Present address:Istituto di Struttura della Materia-CNR(ISM-CNR) via Fosso del Cavaliere 10000133RomaItaly Present address:IMDEA Nanoscience C/Faraday 9Campus de Cantoblanco28049MadridSpain Max Planck Institute for Polymer Research 55128MainzGermany Empa Swiss Federal Laboratories for Materials Science and Technologynanotech@surfaces Laboratory8600DübendorfSwitzerland Organic and Carbon Nanomaterials Unit Okinawa Institute of Science and Technology Graduate University1919-1 TanchaOnna-sonKunigami-gunOkinawa904-0495Japan Institute of Physical Chemistry Johannes Gutenberg University MainzDuesbergweg 10-1455128MainzGermany

Graphene nanoribbons (GNRs) have potential for applications in electronic devices. A key issue, thereby, is the fine-tuning of their electronic characteristics, which can be achieved through subtle structural modifications. These are not limited to the conventional armchair, zigzag, and cove edges, but also possible through incorporation of non-hexagonal rings. On-surface synthesis enables the fabrication and visualization of GNRs with atomically precise chemical structures, but strategies for the incorporation of non-hexagonal rings have been underexplored. Herein, we describe the on-surface synthesis of armchair-edged GNRs with incorporated five-membered rings through the C-H activation and cyclization of benzylic methyl groups. Ortho-Tolyl-substituted dibromobianthryl was employed as the precursor monomer, and visualization of the resulting structures after annealing at 300 °C on a gold surface by high-resolution noncontact atomic force microscopy clearly revealed the formation of methylene-bridged pentagons at the GNR edges. These persisted after annealing at 340 °C, along with a few fully conjugated pentagons having singly-hydrogenated apexes. The benzylic methyl groups could also migrate or cleave-off, resulting in defects lacking the five-membered rings. Moreover, unexpected and unique structural rearrangements, including the formation of embedded heptagons, were observed. Despite the coexistence of different reaction pathways that hamper selective synthesis of a uniform structure, our results provide novel insights into on-surface reactions en route to functional, non-benzenoid carbon nanomaterials.

关键词： graphene nanoribbons on-surface synthesis scanning-tunneling microscope noncontact atomic force microscope C-H activation

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On-Surface Synthesis of Anthracene-Fused Zigzag Graphene Nanoribbons from 2,7-Dibromo-9,9′-bianthryl Reveals Unexpected Ring Rearrangements

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Precision Chemistry 2024年第2期2卷 81-87页

作者： Xiushang Xu Amogh Kinikar Marco Di Giovannantonio Carlo A.Pignedoli Pascal Ruffieux Klaus Müllen Roman Fasel akimitsu narita Max Planck Institute for Polymer Research 55128 MainzGermany Organic and Carbon Nanomaterials Unit Okinawa Institute of Science and Technology Graduate UniversityKunigami-gunOkinawa 904-0495Japan Empa Swiss Federal Laboratories for Materials Science and Technologynanotech@surfaces Laboratory8600 DübendorfSwitzerland Institute of Structure of Matter-CNR(ISM-CNR) 00133 RomaItaly Institute of Physical Chemistry Johannes Gutenberg University Mainz55128 MainzGermany Department of Chemistry Biochemistry and Pharmaceutical SciencesUniversity of Bern3012 BernSwitzerland

On-surface synthesis has emerged as a powerful strategy to fabricate unprecedented forms of atomically precise graphene nanoribbons(GNRs).However,the on-surface synthesis of zigzag GNRs(ZGNR)has met with only limited ***,we report the synthesis and on-surface reactions of 2,7-dibromo-9,9′-bianthryl as the precursor towardπ-extended *** by scanning tunneling microscopy and high-resolution noncontact atomic force microscopy clearly demonstrated the formation of anthracene-fused *** skeletal rearrangements were also observed,which could be explained by intramolecular Diels-Alder *** calculations of the electronic properties of the anthracene-fused ZGNRs revealed spin-polarized edge-states and a narrow bandgap of 0.20 eV.

关键词： On-surface synthesis Graphene nanoribbon On-surface reaction Rearrangement Edge state

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Numerical Modeling of Growth Kinetics of Pro-eutectoid Ferrite Transformed from Austenite in Fe-C-∑X Alloys

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Journal of Materials Science & Technology 2005年第6期21卷 795-798页

作者： Zhenyu LIU Guodong WANG Toshio narita State Key Lab for Rolling Technology and Automation Northeastern University Shenyang 110004 China Lab for Interface Control Engineering Hokkaido University Sapporo Japan

In the present paper, a numerical modeling was developed to simulate the growth kinetics of ferrite transformed from austenite in Fe-C-∑X （X denotes substitution elements, such as Mn, Ni, Cr etc.） steels by solving the diffusion equation using finite difference method （FDM）. Coupled with the kinetic modeling, thermodynamic calculations were carried out to determine the γ/α phase equilibrium conditions using a para-equilibrium （PE） model. The dissipation of free energy for γ→α phase transformation due to the so-called solute drag effect （SDE） was taken into account in the thermodynamic modeling. With this modeling, simulations on the growth kinetics of ferrite in the steels containing austenite-stabilizing and ferrite-stabilizing elements （such as Ni, Mn and Si, Cr, respectively） were performed, which indicates that it deviates from the parabolic growth rate law after the initial stage of transformation. The results were compared with the experimental values given by Bradley and Aaronson, showing that this model has a reasonably good accuracy to predict the growth kinetics of ferrite.

关键词： Numerical modeling Fe-C-∑X steels γ→α phase transformation Para-equilibrium model

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Diffusion Barrier Coating System and Oxidation Behavior of Coated Alloys

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中国腐蚀与防护学报 2009年第4期29卷 312-313页

作者： T.narita Research Group of Advanced Coatings Hokkaido UniversityKita-13Nishi-8Kita-KuSapporo 060-8628 Japan

1 Introduction Research into the formation of Re-based alloys is in progress in our laboratory to provide a diffusion barrier layer between heat-resistant alloys and Al reservoir layers,which assist in the formation and maintenance a protective Al_2O_3 scale for long periods. Coatings with a two-layered structure comprised of inner Re-based alloy layer and outerβ-NiAl layer with or without Pt addition were successfully formed

关键词：镁合金氧化腐蚀金属

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Axonal remodeling in the corticospinal tract after stroke： how does rehabilitative training modulate it？

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Neural Regeneration Research 2017年第2期12卷 185-192页

作者： Naohiko Okabe Kazuhiko narita Osamu Miyamoto Second Department of Physiology Kawasaki Medical School 577 Matsushima Kurashiki City Okayama Japan

Stroke causes long-term disability, and rehabilitative training is commonly used to improve the consecutive functional recovery. Following brain damage, surviving neurons undergo morphological alterations to reconstruct the remaining neural network. In the motor system, such neural network remodeling is observed as a motor map reorganization. Because of its significant correlation with functional recovery, motor map reorganization has been regarded as a key phenomenon for functional recovery after stroke. Although the mechanism underlying motor map reorganization remains unclear, increasing evidence has shown a critical role for axonal remodeling in the corticospinal tract. In this study, we review previous studies investigating axonal remodeling in the corticospinal tract after stroke and discuss which mechanisms may underlie the stimulatory effect of rehabilitative training. Axonal remodeling in the corticospinal tract can be classified into three types based on the location and the original targets of corticospinal neurons, and it seems that all the surviving corticospinal neurons in both ipsilesional and contralesional hemisphere can participate in axonal remodeling and motor map reorganization. Through axonal remodeling, corticospinal neurons alter their output selectivity from a single to multiple areas to compensate for the lost function. The remodeling of the corticospinal axon is influenced by the extent of tissue destruction and promoted by various therapeutic interventions, including rehabilitative training. Although the precise molecular mechanism underlying rehabilitation-promoted axonal remodeling remains elusive, previous data suggest that rehabilitative training promotes axonal remodeling by upregulating growth-promoting and downregulating growth-inhibiting signals.

关键词： stroke rehabilitative training axonal remodeling corticospinal tract motor map reorganization motor system neurotrophic factor functional compensation neural activity growth promoting signal growth inhibitory signal task-specific training

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Random Vibration Control of Laminated Composite Plates with Piezoelectric Fiber Reinforced Composites

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Acta Mechanica Solida Sinica 2016年第3期29卷 316-327页

作者： Jinqiang Li Zhuorui Ma Zhihua Wang Yoshihiro narita College of Mechanics Shanxi Key Laboratory of Material Strength & Structural ImpactTaiyuan University of Technology Faculty of Engineering Hokkaido University

This paper presents an analysis of the active control of random vibration for lami- nated composite plates using piezoelectric fiber reinforced composites （PFRC）. With Hamilton＇s principle and the Rayleigh-Ritz method, the equation of motion for the resulting electromechani- cal coupling system is derived. A velocity feedback control rule is employed to obtain an effective active damping in the suppression of random vibration. The power spectral density and mean- square displacements of the random vibration for laminated plates under different control gains are simulated and the validity of the present control strategy is confirmed. The effect of piezoelec- tric fiber orientation in the PFRC layer on the random vibration suppression is also investigated. The analytical methodology can be expanded to other kinds of random vibration.

关键词： random vibration active control laminated composite plate velocity feedback,piezoelectric material

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Evaluation of dielectric and piezoelectric behavior of unpoled and poled barium titanate polycrystals with oxygen vacancies using phase field method

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International Journal of Smart and Nano Materials 2016年第4期7卷 265-275页

作者： Fumio narita Takuya Kobayashi Yasuhide Shindo Department of Materials Processing Graduate School of EngineeringTohoku UniversityAoba-yama 6-6-02SendaiJapan

This article studies the dielectric and piezoelectric behavior of unpoled and poled barium titanate(BaTiO_(3))polycrystals with oxygen vacancies.A phase field model is employed for BaTiO_(3) polycrystals,coupled with the time-dependent Ginzburg–Landau theory and the oxygen vacancies diffusion,to demonstrate the interaction between oxygen vacancies and domain *** generate grain structures,the phase field model for grain growth is also *** hysteresis loop and butterfly curve are predicted at room and high *** permittivity,and longitudinal and transverse piezoelectric constants of the BaTiO_(3) polycrystals are then examined for various grain sizes and oxygen vacancy densities.

关键词： Mesomechanics phase field method ferroelectric ceramics piezoelectric property smart materials and structures

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Prediction of the solidification structure of casting and heterogeneous nucleation

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Journal of University of Science and Technology Beijing 2003年第3期10卷 43-46页

作者： K.Ohsasa H.Shirosawa T.narita Hokkaido University Kita-kuSapporo 060-8626JapanHokkaido UniversityKita-kuSapporo 060-8626JapanHokkaido UniversityKita-kuSapporo 060-8626Japan

The frequency of heterogeneous nucleation during the solidification of Al-Sibinary alloy was estimated by comparing experimentally obtained macrostructures of castings withnumerically simulated ones. A molten alloy was unidirectionally solidified from a water-cooledcopper chill in an adiabatic mold. The location of columnar to equiaxed transition (CET) in thesolidified alloy ingot was measured. A numerical simulation for grain structure formation based onthe Monte Carlo method was carried out, and the frequency of heterogeneous nucleation in the alloywas evaluated by producing similar structure with the experimental one. The frequency ofheterogeneous nucleation was expressed as a probabilistic function with an exponential form ofundercooling that deter-mines the probability of nucleation event in the simulation. The value ofthe exponent is regarded as the nucleation parameter. The nucleation parameter of Al-Si binary alloyvaried with initial Si content.

关键词： Al-Si binary alloy nucleation prediction of macro structure probabilistic method

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Characteristics of Tantalum Surface Treated by 6-Triethoxysilylpropylamino-1,3,5-Triazine-2,4-Dithiol Using XPS

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稀有金属材料与工程 2012年第S1期41卷 33-37页

作者： Hirahara Hidetoshi Aisawa Sumio narita Eiichi Mori Katuhito Graduate School of Engineering Iwate UniversityMoriokaIwate 0208551Japan

The characteristic of material surfaces has a vital status in its application,for instance,surface properties of materials play a decisive role in adhesion technology between different materials.A method called molecule adhesion technology which can successfully adhere different materials such as polymers,rubbers,metals and exhibit strong adhesion strength without any adhesive *** this work,the rare metal of tantalum surface treated by corona and a molecular adhesive(6-triethoxysilylpropylamino1,3,5-triazine-2,4-dithiols,TES)has been investigated to clarify the reaction mechanism between tantalum and *** structures of surfaces treated by corona and TES were also *** contains two functional groups:one is alkoxysilyl group which can react with the OH group linked tantalum formed by the corona discharge treatment;the other is dithiol triazinyl group reacted with many other *** tantalum,corona treated and TES treated surfaces situation were analyzed by X-ray photoelectron spectroscopy(XPS).The result shows that the functional structure of OH groups was formed after corona discharge process and TES can be successfully reacted on the tantalum *** research can be as a preparation work to achieve the tantalum and other materials adhesion by using molecule adhesion technology in the MEMS and NEMS electronic device fields.

关键词： tantalum surface functional structure XPS adhesion

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Is branched-chain amino acid nutritional supplementation beneficial or detrimental in heart failure?

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World Journal of Cardiology 2021年第6期13卷 163-169页

作者： Koichi narita Eisuke Amiya Department of Cardiovascular Medicine The University of TokyoTokyo 113-8655Japan

Sarcopenia or cachexia is often complicated in heart *** support,particularly branched-chain amino acid(BCAA)supplementation,is a candidate treatment for improving sarcopenia or cachexia in elderly ***,the efficacy of BCAA supplementation in patients with heart failure has not been established,and the issue is comparatively more ***,there are conflicting reports on the efficacy of BCAA *** evidence for including BCAA supplementation in treating patients with heart failure was reviewed,and the complexity of the issue was discussed.

关键词： Branched-chain amino acid Heart failure Sarcopenia Cachexia Nutrition Branched-chain a-ketoacids

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