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Neuroscience Bulletin 2018年第5期34卷 849-853页

作者： Yasuhide Mitsumoto atsushi Mori Laboratory of Alternative Medicine and Experimental Ther- apeutics Department of Clinical Pharmacy Faculty of Pharmaceutical Sciences Hokuriku University Ho-3 Kana- gawa-machi Kanazawa Ishikawa 920-1181 Japan Department of Perioperative Management System Nagoya University Graduate School of Medicine 65 Tsurumai-cho Showa-ku Nagoya Aichi 466-8550 Japan

As an environmental risk factor, psychological stress may trigger the onset or accelerate the progression of Parkinson＇s disease （PD）. Here, we evaluated the effects of acute restraint stress on striatal dopaminergic terminals and the brain metabolism of 1-methyl-4-phenyl-1,2,3,6-tetrahy- dropyridine （MPTP）, which has been widely used for creating a mouse model of PD. Exposure to 2 h of restraint stress immediately after injection of a low dose of MPTP caused a severe loss of striatal dopaminergic terminals as indicated by decreases in the dopamine transporter protein and dopamine levels compared with MPTP administration alone. Both striatal 1-methyl-4-phenylpyridinium ion （MPP＋） and MPTP concentrations were significantly increased by the application of restraint stress. Striatal monoamine oxidase-B, which catalyzes the oxidation of MPTP to MPP＋, was not changed by the restraint stress. Our results indicate that the enhanced striatal dopaminergic terminal loss in the stressed mice is associated with an increase in the transport of neurotoxin into the brain.

关键词： MPTP MPP+ Mouse model Restraint stress Dopaminergic neuron Degeneration Dopamine transporter Dopamine

Machine learning-based predictions of fatigue life and fatigue limit for steels

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Journal of Materials Science & Technology 2021年第31期90卷 9-19页

作者： steelsLei He ZhiLei Wang Hiroyuki Akebono atsushi Sugeta Department of Materials Science and Engineering Nagoya UniversityFuro-choChikusa-kuNagoya464-8601Japan Department of Mechanical Science and Engineering Hiroshima University1-4-1 KagamiyamaHigashi-HiroshimaHiroshima739-8527Japan

To predict the fatigue life for oblique hyperbola-and bilinear-mode S-N curves of metallic materials with various strengths,a machine-learning approach for direct analysis was ***,to determine the fatigue limit of the utilized materials(AISI 316,AISI 4140 and CA6 NM series)with different S-N curve modes using finite-fatigue life data,a Bayesian optimization-based inverse analysis was *** results indicated that predictions of the fatigue life for the utilized datasets via the random forest(RF)algo rithm for AISI 4140 and CA6 NM,and artificial neural network(ANN)for AISI 316,distribute within 2 factor error lines for most *** the Bayesian optimization-based inverse analysis,the specific explanatory variables corresponding to the optimized maximum fatigue life were treated as the fatigue *** predicted fatigue limits either approximated to or slightly underestimated the experimental results,except for several cases with large *** the inverse analysis to predict the fatigue limit for both S-N curve modes is applicable for current employed ***,the explored maximum fatigue lives via BO corresponding to the predicted fatigue limit were underestimated for AISI 4140 and CA6 NM,and was overestimated for AISI 316 because of effect of shape of S-N *** combining the ANN or RF direct and BO inverse algorithms,whole S-N curves(including the fatigue limit)were evaluated for the S-N curve shapes of the oblique hyperbola and bilinear modes.

关键词： Machine learning Fatigue life prediction Inverse analysis Steels

Aluminum Electroplating on AZ31 Magnesium Alloy with Acetic Anhydride Pretreatment

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Acta Metallurgica Sinica(English Letters) 2022年第12期35卷 1996-2006页

作者： Zelei Zhang atsushi Kitada Kazuhiro Fukami Kuniaki Murase Department of Materials Science and Engineering Kyoto UniversityKyoto 606-8501Japan Department of Chemical System Engineering The University of TokyoTokyo 113-8656Japan

Magnesium(Mg)alloys for metal electroplating require a surface pretreatment,i.e.,the removal of the spontaneously oxidized surface layer(MgO,Mg(OH)_(2),andMgCO_(3)).However,the use of highly toxic and/or corrosive acids in conventional pretreatment processes has become an *** this study,a facile and less toxic pretreatment is demonstrated and applied in aluminum(Al)*** immersion of the AZ31 Mg alloy into acetic anhydride(Ac_(2)O)removed the spontaneously oxidized surface layer and formed a thin but stable magnesium acetate(Mg(OAc)_(2))layer that protects the metal substrate from further *** Al electroplating bath is a concentrated diglyme(G2)-AlCl_(3)organic solution that can readily dissolve Mg(OAc)_(2)to enable direct plating onto a metal *** as-deposited Al layer has a compact and crack-free morphology that improves the corrosion resistance and hardness(2.7 GPa).Owing to the lack of an interfacial oxidized layer,heat treatment led to the successful diff usion of Mg and Al atoms,which increased the hardness to 4.4 *** Ac_(2)O pretreatment of Mg alloys enables the successful Al electroplating and subsequent heat treatment.

关键词： Magnesium alloy Surface modifi cation Electrodeposition Hardness Corrosion resistance

Annealing,solvation,and mirror-plating effects in phosphonium chloroaluminate ionic liquids

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Nano Research 2023年第2期16卷 3348-3357页

The physicochemical properties of a specific ionic liquid(IL)are naturally considered to be constant at a given ***,a series of eutectic melts of trihexyl(tetradecyl)phosphonium chloride([P6,6,6,14]Cl)with aluminum chloride(AlCl3)is an *** viscosity of Al_(2)Cl_(7)−-dominated[P6,6,6,14]Cl–AlCl_(3)ILs(i.e.,AlCl_(3)mole fraction x=0.60–0.67)gradually increased as a function of *** also influenced the ultraviolet–visible spectra,nuclear magnetic resonance spectra,and the glass transition temperature of the *** annealing-induced variations in physicochemical properties were not observed in the AlCl4−-and Cl−-dominated *** particular,the ionic conductivities of the ILs(x=0.60–0.67)were strongly decoupled from their viscosities during *** initio calculations revealed the bending of the long tetradecyl chains in[P6,6,6,14]+coupled with Al_(2)Cl_(7)−,while neither Cl−nor AlCl_(4)−caused *** general,[P6,6,6,14]+-based ILs are recognized as sponge-like structures that consist of nano-scale polar and non-polar *** propose a gradual structurization process in Al_(2)Cl_(7)−-dominated ILs to account for their unusual physicochemical ***,the addition of tetradecane,solvated in the non-polar domains of the ILs,substantially reduced the viscosity of the structured IL with x=*** Al electroplating is possible without a brightener,using the x=0.67 ILs,regardless of annealing or the admixture of tetradecane.

关键词： ionic liquid physicochemical property ab initio calculation electrodeposition

Shedding new light on the dislocation-mediated plasticity in wurtzite ZnO single crystals by photoindentation

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Journal of Materials Science & Technology 2023年第25期156卷 206-216页

作者： Yan Li Xufei Fang Eita Tochigi Yu Oshima Sena Hoshino Takazumi Tanaka Hiroto oguri Shigenobu Ogata Yuichi Ikuhara Katsuyuki Matsunaga Atsutomo Nakamura Department of Mechanical Science and Bioengineering Osaka University1-3 Machikaneyama-choToyonaka 560-8531Japan Department of Materials and Earth Sciences Technical University of Darmstadt64287 DarmstadtGermany Institute of Industrial Science The University of Tokyo4-6-1 KomabaMeguro-kuTokyo 153-8505Japan PRESTO Japan Science and Technology Agency (JST)4-1-8HonchoKawaguchi-shiSaitama 332-0012Japan Department of Materials Physics Nagoya UniversityFuro-choChikusa-kuNagoya 464-8603Japan Institute of Engineering Innovation The University of Tokyo2-11-16 YayoiBunkyo-kuTokyo 113-8656Japan

Dislocation-mediated plasticity in inorganic semiconductors and oxides has attracted increasing research interest because of the promising mechanical and functional properties tuned by *** this study,we investigated the effects of light illumination on the dislocation-mediated plasticity in hexagonal wurtzite ZnO,a representative third-generation semiconductor material.A(0001)45o off sample was specially designed to preferentially activate the basal slip on(0001)*** types of nanoindentation tests were performed under four different light conditions(550 nm,334 nm,405 nm,and darkness),including low-load(60μN)pop-in tests,high-load(500μN)nanoindentation tests,and nanoindentation creep *** maximum shear stresses at pop-in were found to approximate the theoretical shear strength regardless of the light *** activation volume at pop-ins was calculated to be larger in light than in ***-sectional transmission electron microscope images taken from beneath the indentation imprints showed that all indentation-induced dislocations were located beneath the indentation imprint in a thin-plate shape along one basal slip *** indentation-induced dislocations could spread much deeper in darkness than in light,revealing the suppressive effect of light on dislocation *** analytical model was adopted to estimate the elastoplastic stress field beneath the *** was found that dislocation glide ceased at a higher stress level in light,indicating the increase in the Peierls barrier under light ***,nanoindentation creep tests showed the suppression of both indentation depth and creep rate by *** creep also yielded a larger activation volume in light than in darkness.

关键词： Photoindentation Compound semiconductors Oxides Crystal plasticity Dislocations

Uneven Distribution of Pseudotormentus De Wever et Caridroit(Radiolaria,Protozoa):Provincialism of a Permian Planktonic Microorganism

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Acta Geologica Sinica(English Edition) 2016年第5期90卷 1598-1610页

作者： ITO Tsuyoshi FENG Qinglai MATSUOKA atsushi State Key Laboratory of Geo-processes and Mineral Resources China University of Geosciences Graduate School of Science and Technology Niigata University Research Institute of Geology and Geoinformation Geological Survey of Japan Department of Geology Faculty of ScienceNiigata University

The Permian planktonic distribution is not well known,in contrast to other fossil distributions of nekton and *** are representative microfossils of plankton in the Permian *** study compares both correlated radiolarian occurrences（Pseudotormentus De Wever et Caridroit and Quadriremis Nazarov et Ormiston） in literature data from the Pacific Rim and quantitative data from the Liuhuang and Gujingling sections in South *** distributions are concentrated in the Panthalassa,whereas Quadriremis occurrences are distributed over both the Panthalassa and the *** uneven distribution of Pseudotormentus seems to have been controlled by a difference in the oceanic basins,indicating the presence of faunal differences in Permian planktonic microorganisms between the Panthalassa and the *** other words,this study infers the provincialism of Permian planktonic *** uneven distribution is explainable by a hypothesis that Pseudotormentus was strongly affected by a Panthalassan equatorial current.

关键词： palaeobiogeography Palaeotethys Panthalassa Permian radiolaria Pseudotormentus Quadriremis

Topology optimization based on reduction methods with applications to multiscale design and additive manufacturing

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Frontiers of Mechanical Engineering 2020年第1期15卷 151-165页

作者： Emmanuel TROMME atsushi KAWAMOTO James KGUEST Department of Civil Engineering Johns Hopkins UniversityBaltimoreMD 21218USA Toyota Central R&D Labs. Inc.NagakuteAichi 480-1192Japan

Advanced manufacturing processes such as additive manufacturing offer now the capability to control material placement at unprecedented length scales and thereby dramatically open up the design *** includes the considerations of new component topologies as well as the architecture of material within a topology offering new paths to creating lighter and more efficient *** optimization is an ideal tool for navigating this multiscale design problem and leveraging the capabilities of advanced manufacturing ***,the resulting design problem is computationally challenging as very fine discretizations are needed to capture all micro-structural *** this paper,a method based on reduction techniques is proposed to perform efficiently topology optimization at multiple *** method solves the design problem without length scale separation,i.e.,without iterating between the two ***,connectivity between space-varying micro-structures is naturally *** design problems for various types of micro-structural periodicity are performed to illustrate the method,including applications to infill patterns in additive manufacturing.

关键词： multiscale topology optimization micro-structure additive manufacturing reduction techniques substructuring static condensation super-element

Index-based assessment of agricultural drought in a semi-arid region of Inner Mongolia, China

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Journal of Arid Land 2014年第1期6卷 3-15页

作者： Rui LI atsushi TSUNEKAWA Mitsuru TSUBO United Graduate School of Agricultural Sciences Koyama-Minami 4-101Tottori University Arid Land Research Center Tottori University

Agricultural drought is a type of natural disaster that seriously impacts food *** the relationships among short-term rainfall,soil moisture,and crop growth are complex,accurate identification of a drought situation is *** this study,using a conceptual model based on the relationship between water deficit and crop yield reduction,we evaluated the drought process in a typical rainfed agricultural region,Hailar county in Inner Mongolia autonomous region,*** quantify drought,we used the precipitation-based Standardized Precipitation Index(SPI),the soil moisture-based Crop Moisture Index(CMI),as well as the Normalized Difference Vegetation Index(NDVI).Correlation analysis was conducted to examine the relationships between dekad-scale drought indices during the growing season(May–September)and final yield,according to data collection from 2000 to *** results show that crop yield has positive relationships with CMI from mid-June to mid-July and with the NDVI anomaly throughout July,but no correlation with *** analysis of the relationship between the two drought indices shows that the NDVI anomaly responds to CMI with a lag of 1 dekad,particularly in *** examine the feasibility of employing these indices for monitoring the drought process at a dekad time scale,a detailed drought assessment was carried out for selected drought *** results confirm that the soil moisture-based vegetation indices in the late vegetative to early reproductive growth stages can be used to detect agricultural drought in the study ***,the framework of the conceptual model developed for drought monitoring can be employed to support drought mitigation in the rainfed agricultural region of Northern China.

关键词： drought assessment drought index dekad time scale rainfed agriculture

Quantitative analysis with plastic strain indicators to estimate damage induced by fault-slip

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Journal of Rock Mechanics and Geotechnical Engineering 2018年第1期10卷 1-10页

作者： atsushi Sainoki Hani S.Mitri International Research Organization for Advanced Science and Technology Kumamoto University Department of Mining and Materials Engineering McGill University

In the present study, methodologies to evaluate damage around an underground opening due to seismic waves arising from mining-induced fault-slip are examined. First, expressions for an associated flow rule with a failure criterion are developed for biaxial stress conditions, which are implemented into FLAC3D code. A three-dimensional(3D) mine model encompassing a fault running parallel to a steeply dipping orebody is constructed, whereby static and dynamic analyses are performed to extract stopes and simulate fault-slip in dynamic condition, respectively. In the analysis, the developed biaxial model is applied to the stope wall. The fault-slip simulation is performed, considering shearing of fault surface asperities and resultant stress drop driving the fault-slip. Two methodologies to evaluate damage caused by seismic waves arising from the simulated fault-slip are examined:(i) the ratio of dynamic plastic strain increment to elastic strain limit and(ii) plastic strain energy density. For the former one, two types of strain increments are tested, namely effective shear strain increment and volumetric strain *** results indicate that volumetric strain increment is a suitable index for detecting damage near the stope wall, while effective shear strain increment is appropriate for evaluating damage in backfill. The evaluation method with plastic strain energy density is found to be capable of assessing damage accumulated in an extensive area caused by rock mass oscillation due to seismic wave propagation. Possible damage to mine developments in the proximity of a stope is clearly described with the index. The comparison of the two methods clarifies that the former one assesses "instantaneous" damage, which is found to be different from "accumulated" damage calculated using plastic strain energy density, in terms of damage area and its location. It is thus concluded that the combination of the two methodologies leads to more accurate damage assessment as a pr

关键词： Stability of mine opening Mining-induced fault-slip Seismic waves Biaxial stress condition

A method for estimating the fraction of mineral dust in particulate matter using PM2.5-to-PM10 ratios

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Particuology 2016年第5期14卷 114-120页

作者： Nobuo Sugimoto atsushi Shimizu Ichiro Matsui Masataka Nishikawa Center for Environmental Measurement and Analysis National Institute for Environmental Studies 16-20nogawa Tsukuba 305-8506 Japan Tokyo University of Science Environmental Safety Center 1-3 Kagurazaka Shinjuku-ku Tokyo 162-8601Japan

A simple method for estimating the contributions of mineral dust to PM2.5, PM10, or TSP is presented. The method is based on the assumption of external mixing of two types of particles with different PM2.5/PM10 ratios, The method was applied to local and transported dust events observed in Tsukuba, Japan, and was compared with collocated polarization lidar measurements. The method was then applied to three dust events that occurred in Oki, Rishiri, and Ochiishi,Japan, in 2012. The results showed that the method was useful for detecting mineral dust and for qualitatively describing the mixing of dust with anthropogenic aerosols.

关键词： Mineral dust PM2.5 dust fraction PM2.5 to PM10 ratio Atmospheric mixing Lidar Depolarization ratio