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Materials Sciences and Applications 2017年第12期8卷 838-847页

作者： Kazuya Hatano Yuuki Asano Yuuto Kameda Akira Koshio fumio kokai Division of Chemistry for Materials Graduate School of Engineering Mie University Tsu Japan

Germanium (Ge)-carbon (C) core-shell nanowires (NWs), 15 - 80 nm thick and <1 μm long, were grown using continuous-wave laser vaporization of Ge-graphite composite targets in high pressure (0.1 - 0.9 MPa) Ar gas. The NW core was crystalline Ge and the shell was amorphous C. The fraction of the NWs in deposits was changed significantly by the Ge content in the targets and had a maximum at the Ge content of 40 atomic %. With increasing Ar pressure, thicker NWs were grown. A strong correlation was evident between the two diameters of the NW and nanoparticle (NP) attached with the tip of the NW. The growth of the NWs can be explained by the formation of Ge-C liquid-like molten NPs having a specific range of size and composition and precipitation of Ge and C followed by phase separation.

关键词： Laser Vaporization Germanium Carbon Nanowire Core Shell

Global Warming in Japanese Cities from 1960 to 2019 Using Machine Learning

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Journal of Geoscience and Environment Protection 2024年第9期12卷 198-214页

作者： fumio Maruyama Department of Sports and Health Science Matsumoto University Matsumoto Japan

In this study, we investigated the variations in warming between Japanese cities for 1960-1989, and 1990-2019 using principal component analysis (PCA) and k-means clustering. The precipitation and sunshine hours exhibited opposite tendencies in the PCA results. It was found that 1960M and 1990M had a correlation (r = 0.51). The 1960M and 1990M are the mean temperature anomalies in Japanese cities for 1960-1989 and 1990-2019, respectively. There was a strong correlation between temperature and precipitation (r = 0.62). There was an inverse correlation between 1960M and sunshine hours (r = −0.25), but a correlation between 1990M and sunshine hours (r = 0.11). Sunshine hours had less effect on the 1960M but more impact on the 1990M. The k-means clustering for 1960M and 1990M can be classified into four types: high 1960M and high 1990M, which indicates that global warming is progressing rapidly (Sapporo, Tokyo, Kyoto, Osaka, Fukuoka, Nagasaki), low 1960M and low 1990M, global warming is progressing slowly (Nemuro, Ishinomaki, Yamagata, Niigata, Fushiki, Nagano, Karuizawa, Mito, Suwa, Iida, Hamada, Miyazaki, Naha), low 1960M and high 1990M, global warming has accelerated since 1990 (Utsunomiya, Kofu, Okayama, Hiroshima), and normal 1960M and normal 1990M, the rate of warming is normal among the 38 cities (Asahikawa, Aomori, Akita, Kanazawa, Maebashi, Matsumoto, Yokohama, Gifu, Nagoya, Hamamatsu, Kochi, Kagoshima). Higher annual temperatures were correlated with higher annual precipitation according to the k-means clustering of temperature and precipitation. Two of the four categories consisted of places with high annual temperatures and high precipitation (Fushiki, Kanazawa, Kochi, Miyazaki, Kagoshima, Naha, Ishigakijima), and places with low annual temperatures and low precipitation (Asahikawa, Nemuro, Sapporo, Karuizawa).

关键词： Global Warming Japan Machine Learning Principal Component Analysis K-Means Clustering

Estimation of Return Level for Maximum Daily and Hourly Precipitation in Nagano Prefecture, Japan, Using the Extreme Value Theory

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Open Journal of Applied Sciences 2024年第8期14卷 2065-2087页

作者： fumio Maruyama Department of Sports and Health Science Matsumoto University Matsumoto Japan

The weather in Nagano Prefecture, Japan, can be roughly classified into four types according to principal component analysis and k-means clustering. We predicted the extreme values of the maximum daily and hourly precipitation in Nagano Prefecture using the extreme value theory. For the maximum daily precipitation, the vales of ξ in Matsumoto, Karuizawa, Sugadaira, and Saku were positive;therefore, it has no upper bound and tends to take large values. Therefore, it is dangerous and caution is required. The values of ξ in Nagano, Kisofukushima, and Minamishinano were determined to be zero, therefore, there was no upper limit, the probability of obtaining a large value was low, and caution was required. We predicted the maximum return levels for return periods of 10, 20, 50, and 100 years along with respective 95% confidence intervals in Nagano, Matsumoto, Karuizawa, Sugadaira, Saku, Kisofukushima, and Minamishinano. In Matsumoto, the 100-year return level was 182 mm, with a 95% CI [129, 236]. In Minamishinano, the 100-year return level was 285 mm, with a 95% CI [173, 398]. The 100-year return levels for the maximum daily rainfall were 285, 271, and 271 mm in Minamishinano, Saku, and Karuizawa, respectively, where the changes in the daily maximum rainfall were larger than those at other points. Because these values are large, caution is required during heavy rainfall. The 100-year return levels for the maximum daily and hourly precipitation were similar in Karuizawa and Saku. In Sugadaira, the 100-year return level for a maximum hourly rainfall of 107.2 mm was larger than the maximum daily rainfall. Hence, it is necessary to be careful about short-term rainfall events.

关键词： Extreme Value Theory Maximum Daily and Hourly Precipitation Principal Component Analysis K-Means Clustering

Synergistic effects of Pleistocene geological and climatic events on complex phylogeographic history of widespread sympatric species of Megaloptera in East Asia

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Zoological Research 2024年第5期45卷 1131-1146页

作者： Ai-Li Lin Ming-Ming Zou Li-Jun Cao fumio Hayashi Ding Yang Xing-Yue Liu Department of Entomology China Agricultural UniversityBeijing 100193China Sanya Institute of China Agricultural University SanyaHainan 572025China International Joint Laboratory of Taxonomy and Systematic Evolution of Insecta Henan Institute of Science and TechnologyXinxiangHenan 453003China Institute of Plant and Environmental Protection Beijing Academy of Agriculture and Forestry SciencesBeijing 100097China Department of Biology Tokyo Metropolitan UniversityHachioji-shiTokyo 192-0397Japan

Unraveling the phylogeographic histories of species remains a key endeavor for comprehending the evolutionary processes contributing to the rich biodiversity and high endemism found in East *** this study,we explored the phylogeographic patterns and demographic histories of three endemic fishfly and dobsonfly species(Neochauliodes formosanus,Protohermes costalis,and Neoneuromus orientalis)belonging to the holometabolan order *** species,which share a broad and largely overlapping distribution,were analyzed using comprehensive mitogenomic *** findings revealed a consistent influence of vicariance on the population isolation of *** and *** between Hainan,Taiwan,and the East Asian mainland during the early Pleistocene,potentially hindering subsequent colonization of the later diverged *** to these ***,we unveiled the dual function of the major mountain ranges in East Asia,serving both as barriers and conduits,in shaping the population structure of all three ***,we demonstrated that these co-distributed species originated from Southwest,Southern,and eastern Central China,respectively,then subsequently migrated along multi-directional routes,leading to their sympatric distribution on the East Asian ***,our results highlighted the significance of Pleistocene land bridges along the eastern coast of East Asia in facilitating the dispersal of mountain-dwelling insects with low dispersal ***,this study provides novel insight into the synergistic impact of Pleistocene geological and climatic events in shaping the diversity and distribution of aquatic insects in East Asia.

关键词： Comparative phylogeography Island biogeography Pleistocene glaciation Corydalidae East Asia

Highly-efficient VCSEL breaking the limit

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Light(Science & Applications) 2024年第6期13卷 1021-1021页

作者： Dieter Bimberg fumio Koyama Kenichi Iga TU Berlin Hardenbergstr.3610623BerlinGermany Bimberg Chinese-German Center for Green Photonics Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesNo.3888 Dong Nan Hu RoadChangchun130033China Tokyo Institute of Technology Nagatsuta 4259Midori-kuYokohama226-8501Japan

VCSELs have become indispensable in the realms of datacenter networks and three-dimensional sensing thanks to their high-energy efficiencies,low-cost and the scalability of their two-dimensional *** boast high energy-efficiency,exceeding 50%at low bias currents,superiority over edge-emitting lasers,particularly for optical interconnects within datacenter ***,there has been no breakthroughs in the efficiency of VCSELs for over a decade.

关键词： limit breakthrough Highly

New functions of VCSEL-based optical devices Invited Paper

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Chinese Optics Letters 2008年第10期6卷 755-762页

作者： fumio Koyama Microsystem Research Center Precision and Intelligence LaboratoryTokyo Institute of Technology 4259-R2-22 NagatsutaMidori-kuYokohama 226-8503Japan

We have seen a lot of unique features off vertical cavity surface emitting lasers （VCSELs）, such as low power consumption, wafer-level testing, small packaging capability, and so on. The market of VCSELs has been growing up rapidly in recent years and they are now the key devices in local area networks using multi-mode optical fibers. In addition, new functions on VCSELs have been demonstrated. In this paper, the recent advances of VCSEL photonics will be reviewed which include the wavelength engineering and the athermal operation based on microelectro mechanical system （MEMS） technologies. Also, this paper explores the potential and challenges for new functions of VCSELs, including high-speed control of optical phase, slow light devices, plasmonic VCSELs, and so on.

关键词： VCSEL New functions of VCSEL-based optical devices Invited Paper

Fatigue Property of Additively Manufactured Ti-6Al-4V under Nonproportional Multiaxial Loading

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Chinese Journal of Mechanical Engineering 2021年第6期34卷 76-84页

作者： Yuya Kimura fumio Ogawa Takamoto Itoh Graduate School of Science&Engineering Ritsumeikan UniversityShiga 5258577Japan Fracture and Reliability Research Institute Graduate School of Tohoku UniversityMiyagi 9808579Japan Department of Mechani-cal Engineering Ritsumeikan UniversityShiga 5258577Japan

The low cycle fatigue strength properties of the additively manufactured Ti-6Al-4V alloy are experimentally investi-gated under proportional and nonproportional multiaxial *** fatigue tests were conducted using hollow cylinder specimens with and without heat treatments,at room temperature in *** fatigue tests were conducted:one for proportional loading and one for nonproportional *** proportional loading was represented by a push-pull strain path(PP)and the nonproportional loading by a circle strain path(Cl).The failure lives of the additively manufactured specimens were clearly reduced drastically by internal voids and ***,the sizes of the defects were measured,and the defects were found not to cause a reduction in fatigue strength above a critical *** fracture surface was observed using scanning electron microscopy to investigate the fracture mechanisms of the additively manufactured specimens under the two types of strain *** fracture patterns were recognized for each strain paths;however,both showed retention of the crack propagation,despite the presence of numerous defects,probably because of the interaction of the *** crack propagation properties of the materials with numerous defects under nonproportional multiaxial loading were clarified to increase the reliability of the additively manufactured components.

关键词： Additive manufacturing Ti-6Al-4V Low cycle fatigue Multiaxial stress Nonproportional loading Internal defect

s cascade reinforcement likely when sympatric tnd allopatric populations exchange migrants？

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Current Zoology 2016年第2期62卷 155-167页

作者： Roman YUKILEVICH fumio AOKI Department of Biology Union College Schenectady NY 12308 Department of Ecology and Evolution Stony Brook University Stony Brook NY 11794

When partially reproductively isolated species come back into secondary contact, these taxa may diverge in mating preferences and sexual cues to avoid maladaptive hybridization, a process known as reinforcement. This phenomenon often leads to reproductive character displacement （RCD） between sympatric and allopatric populations of reinforcing species that differ in their exposure to hybridization. Recent discussions have reinvigorated the idea that RCD may give rise to additional speciation between conspecific sympatric and allopatric populations, dubbing the concept ＂cascade reinforcement.＂ Despite some empirical studies supporting cascade reinforcement, we still know very little about the conditions for its evolution. In the present article, we address this question by developing an individual-based population genetic model that explicitly simulates cascade reinforcement when one of the hybridizing species is split into sympatric and allopatric populations. Our results show that when sympatric and allopatric populations reside in the same environment and only differ in their exposure to maladaptive hybridization, migration between them generally inhibits the evolution of cascade by spreading the reinforcement alleles from sympatry into allopatry and erasing RCD. Under these conditions, cascade reinforcement only evolved when migration rate between sympatric and allopatric populations was very low. This indicates that stabilizing sexual selection in allopatry is generally ineffective in preventing the spread of reinforcement alleles. Only when sympatric and allopatric populations experienced divergent ecological selection did cascade reinforcement evolve in the presence of substantial migration. These predictions clarify the conditions for cascade reinforcement and facilitate our understanding of existing cases in nature.

关键词： Dobzhansky-Muller incompatibilities hybrid zones reproductive character displacement reproductive isolation secondary contact sexual isolation speciation

Thermal Conductivity and Tensile Properties of Carbon Nanofiber-Reinforced Aluminum-Matrix Composites Fabricated via Powder Metallurgy: Effects of Ball Milling and Extrusion Conditions on Microstructures and Resultant Composite Properties

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Acta Metallurgica Sinica(English Letters) 2019年第5期32卷 573-584页

作者： fumio Ogawa Shuji Yamamoto Chitoshi Masuda Department of Mechanical Engineering College of Science and Engineering Ritsumeikan University Kanto Gakuin University Kagami Memorial Institute for Materials Science and Technology Waseda University

Carbon nanofiber(CNF)-reinforced aluminum-matrix composites were fabricated via ball milling and spark plasma sintering(SPS), SPS followed by hot extrusion and powder extrusion. Two mixing conditions of CNF and aluminum powder were adopted: milling at 90 rpm and milling at 200 rpm. After milling at 90 rpm, the mixed powder was sintered using SPS at 560 °C. The composite was then extruded at 500 °C at an extrusion ratio of 9. Composites were also fabricated via powder extrusion of powder milled at 200 rpm and 550 °C with an extrusion ratio of 9(R9) or 16(R16). The thermal conductivity and tensile properties of the resultant composites were evaluated. Anisotropic thermal conductivity was observed even in the sintered products. The anisotropy could be controlled via hot extrusion. The thermal conductivity of composites fabricated via powder extrusion was higher than those fabricated using other methods. However, in the case of specimens with a CNF volume fraction of 4.0%, the thermal conductivity of the composite fabricated via SPS and hot extrusion was the highest. The highest thermal conductivity of 4.0% CNF-reinforced composite is attributable to networking and percolation of CNFs. The effect of the fabrication route on the tensile strength and ductility was also investigated. Tensile strengths of the R9 composites were the highest. By contrast, the R16 composites prepared under long heating duration exhibited high ductility at CNF volume fractions of 2.0% and 5.0%. The microstructures of composites and fracture surfaces were observed in detail, and fracture process was elucidated. The results revealed that controlling the heating and plastic deformation during extrusion will yield strong and ductile composites.

关键词： Al composite Carbon nanofiber Ball milling Hot extrusion Microstructure and performance

A New Acylated Anthocyanin from the Red Flowers of Camellia hongkongensis and Characterization of Anthocyanins in the Section Camellia Species

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Journal of Integrative Plant Biology 2009年第6期51卷 545-552页

作者： fumio Hashimoto Keiichi Shimizu Yusuke Sakata Department of Horticultural Science Faculty of Agriculture Kagoshima UniversityKagoshima 890-0065 Japan

Twelve anthocyanins （1-12） were isolated from the red flowers of Camellia hongkongensis Seem. by chromatography using open columns. Their structures were elucidated on the basis of spectroscopic analyses, that is, proton-nuclear magnetic resonance, carbon 13-nuclear magnetic resonance, heteronuclear multiple quantum correlation, heteronuclear multiple bond correlation, high resolution electrospray ionization mass and ultraviolet visible spectroscopies. Out of these anthocyanins, a novel acylated anthocyanin, cyanidin 3-O-（6-O-（Z）-p-coumaroyl）-β-galactopyranoside （6）, two known acylated anthocyanins, cyanidin 3-O-（6-O-（E）-p-coumaroyl）-β-galactopyranoside （7） and cyanidin 3-O-（6-O-（E）-caffeoyl）-^- galactopyranoside （8）, and three known delphinidin glycosides （10-12） were for the first time isolated from the genus Camellia. Furthermore, pigment components in C. japonica L., C. chekiangoleosa Hu and C. semiserrata Chi were studied. The results indicated that the distribution of anthocyanins was differed among these species. Delphinidin glycoside was only detected in the flowers of C. hongkongensis, which is a special and important species in the section Camellia. Based on the characterization of anthocyanins in the section Camellia species, there is a close relationship among these species, and C. hongkongensis might be an important parent for creating new cultivars with bluish flower color.

关键词： acylated anthocyanin Camellia hongkongensis Camellia japonica Camellia chekiangoleosa Camellia semiserrata.