記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1088/1361-648x/aa9e70

DOI： 10.1088/1361-648x/aa9e70

Kyutacar

担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1021/acs.chemmater.7b01703

DOI： 10.1021/acs.chemmater.7b01703

Kyutacar

担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1039/c5cp07806g

DOI： 10.1039/c5cp07806g

Kyutacar

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1021/acs.chemmater.5c00128

DOI： 10.1021/acs.chemmater.5c00128

Kyutacar

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1080/14686996.2024.2346068

DOI： 10.1080/14686996.2024.2346068

Kyutacar

記述言語：英語   掲載種別：研究論文（学術雑誌）

<jats:p>Understanding wildlife behavior, including accurate identification, processing, and interpretation of activities or cues, is important to behavioral biology and corresponding conservation strategies. We characterized the breeding activities of the critically endangered White-rumped Vulture Gyps bengalensis following a sequential pattern from courtship to fledging. We recorded 4,160 visual observations of 20 behaviors of eight pairs of White-rumped Vultures from September 2021–April 2022 and constructed Markov chain models to model three composite behaviors (i.e., breeding, foraging, and roosting). We found that vultures at four nests displayed >70% of the time in breeding behavior, and each nest produced offspring, indicating a potential correlation between breeding behavior and successful reproductive outcomes. Our model explained each composite behavior with high accuracy. Identifying behaviors White-rumped Vulture have practical applications for developing management plans for their conservation, including the timing of critical reproductive events. Our findings and approach can improve our understanding of White-rumped Vulture behavioral ecology and conservation and have applications for other species.</jats:p>

DOI： 10.31893/jabb.23024

Kyutacar

CiNii Research

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.jcrysgro.2023.127333

DOI： 10.1016/j.jcrysgro.2023.127333

記述言語：英語   掲載種別：研究論文（学術雑誌）

Li-excess electrode materials potentially boost the energy density of Li-ion batteries, but the origin of the instability of anionic redox in cation-disordered rocksalt material is still under debate. In this study, a binary system of Li3NbO4-CoO is targeted as electrode materials for lithium storage applications. In this binary system, stoichiometric LiCo2/3Nb1/3O2 crystallizes into a rocksalt-type structure with partial ordering of Nb ions. Upon increase of the Li3NbO4 fraction, cation ordering is lost, forming a cation-disordered rocksalt structure in Li-excess phases. Although Li-excess Li4/3Co2/9Nb4/9O2 delivers a large reversible capacity as electrode materials, inferior cyclability and large voltage hysteresis for charge/discharge curves are noted. Irreversible structural changes in electrochemical cycles are also evidenced from results of in situ XRD measurements, suggesting that anionic redox is destabilized for Li4/3Co2/9Nb4/9O2. X-ray absorption spectroscopy reveals that partial stabilization of ligand holes as observed in SrCoO3 is achieved for these oxides. Ligand holes are more effectively stabilized for Li7/6Co4/9Nb7/18O2 with less Li-excess and Co-rich composition. Through systematic study of the binary system of Li3NbO4-CoO with different chemical compositions, factors affecting reversibility and irreversibility of anionic redox are further discussed.

Kyutacar

CiNii Research

その他リンク： https://ynu.repo.nii.ac.jp/records/2001328

記述言語：英語   掲載種別：研究論文（学術雑誌）

<jats:title>Abstract</jats:title><jats:p>First‐principles calculations were performed to reveal an effect of Ca vacancies on the stability of substitutional divalent cations M<jats:sup>2+</jats:sup> (M = Mg, Zn, Sr) in Ca‐deficient hydroxyapatite (dHAp). M<jats:sup>2+</jats:sup> concentrations up to 20 mol% in dHAp were considered, and the most stable substitutional sites and their lowest energy configurations in the dHAp lattice were examined with the aid of a generic algorithm method. It was found that defect formation energies of substitutional M<jats:sup>2+</jats:sup> are lower in dHAp than in stoichiometric HAp (sHAp) at all M<jats:sup>2+</jats:sup> concentrations. This indicates that these M<jats:sup>2+</jats:sup> ions are more favorably involved in dHAp than in sHAp, which is in reasonable agreement with experiment. Detailed analyses on atomic structures in dHAp show that the presence of a Ca vacancy varies its surrounding Ca–O bond lengths over a wide area so that Ca–O polyhedrons with various sizes are produced. As a result, M<jats:sup>2+</jats:sup> ions can predominantly occupy Ca sites at which M<jats:sup>2+</jats:sup> fits better, depending on the ionic radii of M<jats:sup>2+</jats:sup>. For Zn<jats:sup>2+</jats:sup> substitution in dHAp, its defect formation energy decreases more with the increasing concentrations and has the minimum value at 15 mol%. Such a trend can be understood from changes in effective coordination numbers of Zn in dHAp.</jats:p>

DOI： 10.1111/jace.18853

CiNii Research

記述言語：英語   掲載種別：研究論文（学術雑誌）

Dependence on lithium-ion batteries for automobile applications is rapidly increasing. The emerging use of anionic redox can boost the energy density of batteries, but the fundamental origin of anionic redox is still under debate. Moreover, to realize anionic redox, many reported electrode materials rely on manganese ions through π-type interactions with oxygen. Here, through a systematic experimental and theoretical study on a binary system of Li₃NbO₄–NiO, we demonstrate for the first time the unexpectedly large contribution of oxygen to charge compensation for electrochemical oxidation in Ni-based materials. In general, for Ni-based materials, e.g., LiNiO₂, charge compensation is achieved mainly by Ni oxidation, with a lower contribution from oxygen. In contrast, for Li₃NbO₄–NiO, oxygen-based charge compensation is triggered by structural disordering and σ-type interactions with nickel ions, which are associated with a unique environment for oxygen, i.e., a linear Ni–O–Ni configuration in the disordered system. Reversible anionic redox with a small hysteretic behavior was achieved for LiNi₂/₃Nb₁/₃O₂ with a cation-disordered Li/Ni arrangement. Further Li enrichment in the structure destabilizes anionic redox and leads to irreversible oxygen loss due to the disappearance of the linear Ni–O–Ni configuration and the formation of unstable Ni ions with high oxidation states. On the basis of these results, we discuss the possibility of using σ-type interactions for anionic redox to design advanced electrode materials for high-energy lithium-ion batteries.

DOI： 10.1021/acscentsci.2c00238

Kyutacar

CiNii Research

その他リンク： https://ynu.repo.nii.ac.jp/records/2001332

記述言語：英語   掲載種別：研究論文（学術雑誌）

<jats:p>Experimental, computational, and informatics approaches are applied to investigate NASICON-type LiZr<jats:sub>2</jats:sub>(PO<jats:sub>4</jats:sub>)<jats:sub>3</jats:sub> as promising solid electrolytes for all solid-state Li metal batteries.</jats:p>

DOI： 10.1039/d2cc01526a

Kyutacar

CiNii Research

その他リンク： http://pubs.rsc.org/en/content/articlepdf/2022/CC/D2CC01526A

記述言語：英語   掲載種別：研究論文（学術雑誌）

Abstract To find out growing rules for huge clusters of self-interstitials detected in as-grown Si crystals, i.e., Frank partial dislocation loops (FDLs), approach processes forming a di-interstitial from two individual self-interstitials are investigated by ab initio calculations. Interactions between two self-interstitials in a Si crystal are analyzed by changes of both an energy and a stress around the defects in their relative configurations. Interestingly, relations of energy and stress of two self-interstitials that are adjacent to each other show systematic changes and are categorized into three groups. Characteristic structures of di-interstitials are found as rules for constructing FDLs by collecting self-interstitials one by one.

DOI： 10.1016/j.jcrysgro.2021.126313

CiNii Research

その他リンク： https://api.elsevier.com/content/article/PII:S0022024821002888?httpAccept=text/xml

記述言語：英語   掲載種別：研究論文（その他学術会議資料等）

CiNii Article

CiNii Research

その他リンク： http://id.ndl.go.jp/bib/031596201

記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）

DOI： 10.11470/jsapmeeting.2021.1.0_2718

Kyutacar

CiNii Research

記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）

DOI： 10.11470/jsapmeeting.2021.1.0_2719

Kyutacar

CiNii Research

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

During the recent years, much attention has been given to understand the behavior of king cobra. However, there is no report regarding pose tracking and usage of mathematical model that explain the mechanism of biting dynamics of king cobra. In this study a new method called body part localization technique which is often used in computer vision field is applied for detail behavior learning of king cobra. We explored the method of minimizing the time of direct observation by using deep learning technique. Firstly, we applied the approach of body part localization in order to explore the pose data leading to behavior analysis. Secondly, we formulated a Markov chain model to explain the dynamics of king cobra biting behavior. This model describes the significant potential states of biting behavior by using mathematical model leading to predict the behavioral transition from one state to another. From our investigation we found that king cobra at a normal state will also be irritated if the charmer put external pressure and might have chances of getting injured by 18%. Therefore, even a veteran charmer needs to be very careful while handling king cobra during entertainment show. We also concluded that the body part localization by using body landmarks in freely condition is more effective method to identify the king cobra's body part leading to behavior analysis as the disturbance of its habitation is sharply decreased than that of the repeated direct observation method.

DOI： 10.1109/nana51271.2020.00078

CiNii Research

記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）

DOI： 10.11470/jsapmeeting.2020.2.0_2160

Kyutacar

CiNii Research

記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）

DOI： 10.11470/jsapmeeting.2020.2.0_2159

Kyutacar

CiNii Research

記述言語：英語   掲載種別：研究論文（学術雑誌）

<jats:p>We have examined the formation of a two-dimensional (2D) new carbon network by inducing the general Stone–Wales transformation between adjacent C60 molecules in a 2D dumbbell-type C60 polymer film. Structural changes in pristine C60 films after ultraviolet-visible (UV-vis) light and electron-beam (EB) irradiations were studied using in situ scanning tunneling microscope (STM) and in situ Fourier-transformed infrared (IR) spectroscopy, in combination with first-principles calculations based on density functional theory. Analyses of STM images and depth profiles found that three types of photopolymerized dumbbell-shaped dimers and trimers are formed on the surface layers of pristine C60 films: (i) [2+2] C60 dimers formed in a lateral direction, (ii) [2+2] dimerization of C60 between the first and second layers, and (iii) a triangular [2+2] C60 trimer along a lateral direction. As UV-vis light irradiation time increases, a comparison between experimental and theoretical IR spectra indicated that 2D dumbbell-shaped C60 polymers are formed within a few surface layers of the C60 film (in a similar manner, a 1D dumbbell-shaped polymer is also formed in a shallow space of the C60 film), whereas a [2+2] dumbbell-shaped dimer is formed in any bulk space of the film. Thereafter, when the EB was irradiated to the photopolymerized C60 film, the evolution of IR spectra with respect to EB irradiation time suggested that the 2D dumbbell-type C60 polymer is not decomposed but structurally changed to form a new network polymer.</jats:p>

DOI： 10.1063/5.0018985

Kyutacar

CiNii Research

その他リンク： https://pubs.aip.org/aip/adv/article-pdf/doi/10.1063/5.0018985/9048080/085212_1_online.pdf

記述言語：英語   掲載種別：研究論文（学術雑誌）

A binary system of Li2TiO3-LiMnO2 is systematically examined by joint experimental and theoretical studies as electrode materials for Li storage applications. Increase in a fraction of Li2TiO3 effectively activates anionic redox, and thus holes are reversibly formed on oxygen by electrochemical oxidation. Such holes are energetically stabilized through pi-type interaction with Mn t(2g) orbital as suggested by theoretical calculation. However, excess enrichment of Li2TiO3 fractions in this binary system results in the oxygen loss as an irreversible process on delithiation because of a non-bonding character for Ti-O bonds coupled with the formation of O-O dimers, which are chemically and electrochemically unstable species. Additionally, detailed electrochemical study clearly shows that Li migration kinetics is relatively slow, presumably coupled with low electronic conductivity. Nevertheless, nanosizing of primary particles is an effective strategy to overcome this limitation. The nanosized sample prepared by mechanical milling delivers a large reversible capacity, similar to 300 mA h g(-1), even at room temperature and shows much improved capacity retention. Formation and stabilization of holes for the nanosized sample are also directly evidenced by soft X-ray absorption spectroscopy. From these results, factors affecting the reversibility of anionic redox as emerging new chemistry and its possibility for energy storage applications are discussed in more details.

DOI： 10.1016/j.mattod.2020.03.002

Kyutacar

CiNii Research

その他リンク： https://ynu.repo.nii.ac.jp/records/2001339

記述言語：英語   掲載種別：研究論文（学術雑誌）

<jats:p>Currently, NASICON-type LiZr2(PO4)3 (LZP)-related materials are attracting attention as solid electrolytes. There are experimental reports that Li-ion conductivity can be improved by doping a small amount of Ca or Y into stoichiometric LZP. In previous studies, doping with only one element having a narrow search space has been attempted, and thus, further improvement of the Li-ion conductivity is conceivable by using multi-element doping. When multi-element doping is attempted, because the search space becomes enormous, it is necessary to evaluate the Li-ion conductivity using a low-cost method. Here, force-field molecular dynamics using a bond valence force field (BVFF) approach was performed to evaluate the Li-ion conductivity. We confirmed that the Li-ion conductivity of stoichiometric LZP derived from BVFF (6.2 × 10−6 S/cm) has good agreement with the first principle calculation result (5.0 × 10−6 S/cm). Our results suggest that the Li-ion conductivity can be further improved by simultaneously doping LZP with Ca and Y [6.1 × 10−5 S/cm, Li35/32Ca1/32Y1/32Zr31/16(PO4)3]. In addition, Bayesian optimization, which is an informatics approach, was performed using exhaustively computed conduction property datasets in order to validate efficient materials search. The averages for Bayesian optimization over 1000 trials show that the optimal composition can be found about seven times faster than by random search.</jats:p>

DOI： 10.1063/5.0007414

Kyutacar

CiNii Research

その他リンク： https://pubs.aip.org/aip/apm/article-pdf/doi/10.1063/5.0007414/14564921/041112_1_online.pdf

担当区分：筆頭著者   記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）

DOI： 10.11470/jsapmeeting.2020.1.0_3636

Kyutacar

CiNii Research

記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）

DOI： 10.11470/jsapmeeting.2020.1.0_390

Kyutacar

CiNii Research

記述言語：英語   掲載種別：研究論文（学術雑誌）

Artificial neural-network (ANN) interatomic potentials for simulating atomic structures and energetics of grain boundaries (GBs) in silicon were constructed and integrated into structural optimization and molecular dynamics (MD) algorithms. A training dataset including various atomic environments of symmetric tilt GBs was generated by performing density-functional-theory (DFT) calculations. The ANN potential after training was found to be capable of approximating the potential-energy surface at GBs even with dangling bonds and large atomic displacements at high temperatures, which cannot be well reproduced with empirical interatomic potentials. Additionally, reliability of the ANN potential for molecular simulations was evaluated. GB structures optimized or equilibrated by the ANN molecular simulations were also energetically lower for DFT calculations, without significant errors. The ANN potential is therefore expected to greatly reduce structural-optimization iterations and required time steps to acquire stable or equilibrium GB structures in MD simulations, enabling us to address even large-scale systems of general GBs in silicon, with high accuracy and low computational cost.

DOI： 10.1103/physrevmaterials.4.014605

Kyutacar

CiNii Research

その他リンク： https://link.aps.org/article/10.1103/PhysRevMaterials.4.014605

担当区分：筆頭著者   記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）

DOI： 10.11470/jsapmeeting.2019.2.0_4091

Kyutacar

CiNii Research

担当区分：筆頭著者   記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）

DOI： 10.11470/jsapmeeting.2019.1.0_3746

Kyutacar

CiNii Research

記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）

DOI： 10.11470/jsapmeeting.2019.1.0_3745

Kyutacar

CiNii Research

記述言語：英語   掲載種別：研究論文（学術雑誌）

<p>Computational studies on Mg ion conduction in the MgZr₂(PO₄)₆ with both NASICON-type and β sulfate-type structures have been performed.</p>

DOI： 10.1039/c9ra00513g

Kyutacar

CiNii Research

その他リンク： http://pubs.rsc.org/en/content/articlepdf/2019/RA/C9RA00513G

記述言語：英語   掲載種別：研究論文（学術雑誌）

<p>The surface dependent electronic structures of β-FeOOH and γ-FeOOH were studied using density functional calculations.</p>

DOI： 10.1039/c9cp00157c

Kyutacar

CiNii Research

PubMed

その他リンク： http://pubs.rsc.org/en/content/articlepdf/2019/CP/C9CP00157C