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Synthesis and Characterization of LiCo_xMn_(2-x)O_4 Cathode Materials

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Journal of Wuhan University of Technology(Materials Science) 2007年第2期22卷 307-310页

作者：姚耀春 takayuki Watanabe Faculty of Materials and Metallurgy Engineering Kunming University of Science and Technology Department of Environmental Chemistry and Engineering Tokyo Institute of Technology4259 Nagatsuta

LiCoxMn2.04 cathode materials for lithium ion batteries were synthesized by mechanical activation-solid state reaction at 750 ℃ for 24 h in air atmosphere, and their crystal structure, morphology, element composition and electrochemical performance were characterized with XRD, SEM, ICP-AES and charge-discharge test. The experimental results show that all samples have a single spinel structure, well formed crystal shape and uniformly particle size distribution. The lattice parameters of LiCo Mn2-xO4 decrease and the average oxidation states of manganese ions increase with an increase in Co content. Compared with pure LiMn2O4, the LiCo Mn2xO4 （x=0.03-0.12） samples show a lower special capacity, but their cycling life are improved. The capacity loss of LiCo009Mn191O4 and LiCo0.1Mn1.88O4 is only 1.85% and 0.95%, respectively, after the 20th cycle. The improvement of the cycle performance is attributed to the substitution of Co at the Mn sites in the spinel structure, which suppresses the Jahn-Teller distortion and improves the structural stability.

关键词： lithium ion batteries cathode materials spinel LiMn2O4 mechanical activation-solid state method Co-doping

The effect of the 18R-LPSO phase on the fatigue behavior of extruded Mg/LPSO two-phase alloy through a comparative experimental-numerical study

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Journal of Magnesium and Alloys 2021年第1期9卷 130-143页

作者： Fabien Briffod takayuki Shiraiwa Manabu Enoki Department of Materials Engineering The University of Tokyo7-3-1 HongoBunkyo-kuTokyo 113-8656Japan

The fatigue behavior of four extruded Mg-Y-Zn alloys containing different volume fractions of long-period stacking ordered(LPSO)grains was investigated through a comparative study combining experiments and crystal plasticity finite element *** controlled low-cycle fatigue experiments were conducted at different strain amplitudes and revealed a limited cyclic hardening in Mg_(89)Zn_(4)Y_(7)alloy or softening in Mg_(99.2)Zn_(0.2)Y_(0.6)and Mg_(97)Zn_(1)Y_(2)alloys.A decrease in the fatigue life against the plastic strain with the increase in LPSO phase volume fraction was observed and was related the limited ductility of extruded LPSO ***-strain hysteresis curves were used to calibrate and validate a crystal plasticity model taking into account twinning and *** interaction of the different phases on the distribution of local micro-mechanical fields at the grain scale was then analyzed on synthetic microstructures under strain-controlled *** twinning activity was predicted in coarse unrecrystallized grains and tended to disappear with the increase in the LPSO phase volume ***-like facets observed in LPSO grains were related to high tensile stress,especially at the Mg/LPSO interface,due to the limited number of deformation mechanisms in LPSO crystal to accommodate out-of-basal plane *** increase of the fatigue limit with the increase in LPSO phase volume fraction was finally associated with the decreasing presence of coarse unrecrystallizedα-Mg grains due to a higher dynamic recrystallization activity during the extrusion process.

关键词： Magnesium alloy Fatigue Long-period stacking ordered phase Crystal plasticity Finite element method

The NF-Number of a Simplicial Complex

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Algebra Colloquium 2022年第4期29卷 643-650页

作者： takayuki Hibi Hasan Mahmood Department of Pure and Applied Mathematics Graduate School of Information Science and Technology Osaka University SuitaOsaka 565-0871Japan Department of Mathematics Government College University LahorePakistan

Let△bea simplicial complex on[n].TheNF-complex of△is the simplicial complexδ_(NF)(△)on[n]for which the facet ideal of△is equal to the Stanley-Reisner ideal ofδ_(NF)(△).Furthermore,for each k=2,3,....,we introduce the kth NF-complexδ_(NF)^(k)(△),which is inductively defined asδ_(NF)(k)(△)=δ_(NF)(δ_(NF)^(k-1)(△))by settingδ_(NF)^(1)(△)=δ_(NF)(△).One canδ_(NF)^(0)(△)=△.The NF-number of△is the smallest integer k>0 for whichδ_(NF)^(k)(△)■△.In the present paper we are especilly interested in the NF-number of a finite graph,which can be regraded as a simplicial complex of dimension *** is shown that the NF-number of the finite graph K_(n)■K_(m)on[n+m],which is the disjoint union of the complete graphs K_(n)on[n]and K_(m)on[m]for n≥2 and m≥2 with(n,m)≠(2,2),is equal to n+m+*** a corollary,we find that the NF-number of the complete bipartite graph K_(n,m)on[n+m]is also equal to n+m+2.

关键词： Stanley-Reisner complex facet ideal simplicial complex vertex cover

Immunological role of sulfatide in the pathogenesis of multiple sclerosis

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Neural Regeneration Research 2023年第9期18卷 1950-1951页

作者： Mio Hamatani takayuki Kondo Institute for the Advanced Study of Human Biology Kyoto UniversityKyotoJapan Department of Neurology Kansai Medical University Medical CenterMoriguchiJapan

Multiple sclerosis(MS) is a chronic inflammatory demyelinating disease of the central nervous system.A certain population of patients with MS present with a relapse-remitting disease course(RRMS) during the early phase and eventually advance to a progressive course(PMS).While immune modulation therapies have recently seen tremendous success in RRMS,our limited knowledge of pathogenesis hampers the development of effective treatments for PMS.

关键词： pathogenesis sclerosis eventually

High resolution electron energy loss spectroscopy study of the oxidation of Nb(110) surface

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Chinese Science Bulletin 1997年第5期42卷 384-387页

作者： Wang, YS Wei, XM Tian, ZJ Zhai, RS ushikubo, T Sato, K Zhuang, SX State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences China Mitsubishi Chemical Corporation Japan Department of Chemical Physics University of Science and Technology of China Hefei China

NIOBIUM and its oxides are a new kind of materials applied in technical fields, such as catalysis, microelectronics, ceramics and optical glass. In order to understand the surface structure and catalytic activity, much work has been done on the oxidation of niobium. These results indicated that the oxidation process of niobium surface, the distribution and the structure of niobium oxides on the surface are all closely related to the condition of the oxidation process. Due to the high activity of niobium and the complexity of niobium oxide species, up to now there has not been a clear picture of the structure and the forming condition of the niobium oxides. HREELS is a powerful tool to investigate vibrational and structural properties of surface, but the HREELS study of the oxidation of Nb single crystal by O2 has never been reported before. In this note we investigated the oxidation of Nb（110） and the structure and adsorption properties of the oxide film using HREELS, UPS and AES.

关键词： oxygen adsorption Nb (110) surface niobium oxide films high resolution electron energy loss speetroscopy (HREELS).

New Aspects in the Chemistry of Three-membered Ring Compounds Containing a Highly Coordinate Main Group Element

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Chinese Journal of Chemistry 2005年第9期23卷 1267-1269页

作者： takayuki Kawashima Department of Chemistry Graduate School of Science The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo 113 Japan

The title compounds were synthesized by taking advantage of the Martin ligand. Their structures were determined by X-ray crystallography. Pentacoordinate thiasiliranides were hydrolyzed to give the corresponding thiol. Pentacoordinate chalcogenaphosphiranes were found to have polar P-chalcogen bonds, which were confirmed by their reactions with CF3SO3Me to give the corresponding 1-（methylchalcogena）alkylphosphonium triflates and by the solvent-dependent NMR studies.

关键词： Martin ligand P-chalcogen bond three-membered ring compound

A HREELS study of the adsorption of formic acid on slightly oxidized Nb(110) surface

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Science China Chemistry 1997年第1期40卷 9-14页

作者： WANG Yinsheng WEI Xuming TIAN Zhijian ZHAI Runsheng T.ushikubo K.Sato ZHUANG Shuxian State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China Mitsubishi Chemrcal Corporation Japan Department of Chemical Physics University of Science and Technology of ChinaHefei 230026China

An investigation has been made on the adsorption and decomposition of formic acid on slightly oxidized Nb(110)surface(0/Nb atom ratio=0.2)using high resolution electron energy loss spectroscopy(HREELS),and a corresponding surface reaction mode is *** 140 K,formic acid of low exposure on such an Nb(110)surface decomposed to formate,which bonded on Nb in monodentate configuration,simultaneously some formate decomposed to CO,which adsorbed on the *** acid multilayers formed when the exposure was *** the temperature was increased to above 190 K,multilayer formic acid desorbed,and the surface was covered with mon-odentate-bonded formate and *** the temperature range of 250-300 K,chemisorbed formate changed from monodentate configuration into bridging configuration and CO molecules *** decomposition of formate at higher temperatures led to the oxidation of *** formate formed in the high exposure case was so stable that it did not decompose even the temperature was as high as 540 K.

关键词： adsorption of formic acid Nb{110}surface HREELS

Promotion of GSC Technology Innovation by the Green and Sustainable Chemistry Network

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Journal of Chemistry and Chemical Engineering 2010年第5期4卷 14-16页

作者： Kazuhiko Hiyoshi Takashi ushikubo Technological Strategy and Planning Division Japan Chemical Innovation Institute Fuzambo Building 1-3-5 Kanda-JimbochoChiyoda-ku Tokyo 101-0051 Japan

The Green and Sustainable Chemistry Network （GSCN） has been promoting GSC technology development since 2000 in three major activities, holding the GSC symposium, running the GSC Awards, and providing the information related to GSC in Japan. GSCN holds a vision to expand the philosophy of GSC not only to the domestic, but also to the global. As for a regional network in Asia and Oceania, we established the Asia-Oceania GSC Network, and we hope to expand the Network to all countries.

关键词： Green and Sustainable Chemistry Green Chemistry Sustainable Chemistry Asia-Oceania Network.

Measurement of modulation induced by interaction between bubble motion and liquid-phase motion in the decaying turbulence formed by an oscillating-grid

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Particuology 2013年第2期11卷 158-169页

作者： Yasuyuki Nagami takayuki Saito Graduate School of Engineering Shizuoka University Graduate School of Science and Technology Shizuoka University

In multiphase flows, dynamical gas-liquid interactions are essential for in-depth understanding of their multi-scale phenomena and complicated structures. The purpose of the present study is to clearly extract the modulation in bubble motion and liquid motion induced by bubble-liquid interaction and to discuss the relations between bubble motion and liquid-phase motion. For this particular purpose, the decaying turbulence formed in a cylindrical acrylic pipe （diameter 149 mm, height 600 mm） by using an oscillating- grid was employed. Uniform single bubbles were launched from an in-house bubble launching device into the decaying turbulence. By comparing the bubble motion in the stagnant water with that in the oscillating-grid decaying turbulence, the transition of the 2D bubble motion （i.e., zigzagging motion） to 3D motion was enhanced in the latter. In addition, the initial conditions of the bubble motion that was not influenced by the ambient turbulence were carefully confirmed. In the area where the bubble motion started to translate from 2D motion into 3D motion, the modulation of ambient liquid-phase motion was obtained by PIV/LIF measurement. By combining these results, we quantitatively discussed the modulation of the bubble motion and ambient liquid-phase motion and considered the dominant factor for the enhancement to be the bubble-liquid interaction.

关键词： Multiphase flow Gas-liquid interaction Oscillating-grid decaying turbulence Bubble PIV/LIF LIF/HPTS