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Effect of hafnium addition on solidification structure of cast Ti-46Al alloys

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China Foundry 2008年第4期5卷 229-233页

作者： Su Yanqing Zhang Li Guo Jingjie k. maruyama Li Zhiming School of Materials Science and Engineering Harbin Institute of Technology P.O. Box 428 Harbin 150001 China Graduate School of Environmental Studies Tohoku University 02 Aobayama Sendai 980-8579 Japan Department of Materials Science and Engineering Harbin University of Science and Technology P.O. Box 90 Harbin 150080 China

To investigate the effect of hafnium addition on the solidification structure, Ti-46AI alloys with nominal compositions of Ti-46AI-xHf （x = 0, 3, 5, 7）（at.%） were arc-melted into small ingots in an argon atmosphere. The characteristics of the macrostructures and microstructures were studied using a linear intercept method, OM, SEM （BSE）, XRD and TEM. The results showed that the ingots with Hf have near lamellar microstructure in columnar and dendrite morphology. The hafnium concentration has a strong effect on the columnar spacing refinement. Increasing Hf from 0 to 7 （at.%）, the columnar spacing can be reduced from - 1000 to-400 μm. Constitute phases of the ingots are a2, a small amount of B2 and 7. Most of the B2 phases, richer in Hf and leaner in AI and Ti, exist on the node of the dendrite core in block.shape and a little across the lamellar colonies in stick.shape. The 7 phases exist on the boundaries of lamellar colonies in small cellular shape. There also exists a segregation of Hf on the columnar and dendrite core. Particularly, both the a-and ,β-phase form from the melt as prior phases. The possible phase sequencing during solidification and solid-state transformations with Hf is given in this paper.

关键词： hafnium addition solidification structure Ti-46AI alloys phase sequencing

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, Tok.o, k.oto, Osak., Fuk.ok., Nagasak.), low 1960M and low 1990M, global warming is progressing slowly (Nemuro, Ishinomak., Yamagata, Niigata, Fushik., Nagano, k.ruizawa, Mito, Suwa, Iida, Hamada, Miyazak., Naha), low 1960M and high 1990M, global warming has accelerated since 1990 (Utsunomiya, k.fu, Ok.yama, Hiroshima), and normal 1960M and normal 1990M, the rate of warming is normal among the 38 cities (Asahik.wa, Aomori, Ak.ta, k.nazawa, Maebashi, Matsumoto, Yok.hama, Gifu, Nagoya, Hamamatsu, k.chi, k.goshima). 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 (Fushik., k.nazawa, k.chi, Miyazak., k.goshima, Naha, Ishigak.jima), and places with low annual temperatures and low precipitation (Asahik.wa, Nemuro, Sapporo, k.ruizawa).

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, k.ruizawa, Sugadaira, and Sak. were positive;therefore, it has no upper bound and tends to tak. large values. Therefore, it is dangerous and caution is required. The values of ξ in Nagano, k.sofuk.shima, 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, k.ruizawa, Sugadaira, Sak., k.sofuk.shima, 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, Sak., and k.ruizawa, 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 k.ruizawa and Sak.. 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

Marangoni-flow-assisted assembly of single-walled carbon nanotube films for human motion sensing

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Fundamental Research 2024年第3期4卷 570-574页

作者： Yuguang Chen Yitan Li Lu Han Hao Sun Min Lyu Zeyao Zhang Shigeo maruyama Yan Li k.y Laboratory for the Physics and Chemistry of Nanodevices Beijing National Laboratory of Molecular SciencesState Key Laboratory of Rare Earth Materials Chemistry and ApplicationsCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China Academy for Advanced Interdisciplinary Studies Peking UniversityBeijing 100871China Bruk.r(Beijing)Scientific Technology Co.Ltd. Beijing 100192China Department of Mechanical Engineering The University of TokyoTokyo 113-8656Japan Pek.ng University Shenzhen Institute Shenzhen 518057China Pk.-Hk.ST ShenZhen-Hongk.ng Institution Shenzhen 518057China

Single-walled carbon nanotubes(SWCNTs)present excellent electronic and mechanical properties desired in wearable and flexible *** preparation of SWCNT films is the first step for fabricating various *** work.developed a scalable and feasible method to assemble SWCNT thin films on water surfaces based on Marangoni flow induced by surface tension *** films possess a large area of 40 cm×30 cm(extensible),a tunable thick.ess of 15∼150 nm,a high transparency of up to 96%,and a decent *** are ready to be directly transferred to various substrates,including flexible *** strain sensors were fabricated with the films on flexible *** sensors work.d with high sensitivity and *** realizing multi-functional human motion sensing,including responding to voices,monitoring artery pulses,and detecting k.uck.e and muscle actions,the assembled SWCNT films demonstrated the potential for application in smart devices.

关键词： Single-walled carbon nanotubes Marangoni flow Assembly Interfaces Sensors

Formation and Properties of Organic Long Persistent Luminescence Crystals Containing Benzidine Derivatives by Melt Crystallization

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Advances in Chemical Engineering and Science 2024年第1期14卷 1-7页

作者： Norihito Dok. k.yok. maruyama Masaak. Yok.ta Department of Chemistry and Bioengineering Faculty of Engineering Iwate University Morioka Japan

Organic molecules that exhibit long persistent luminescence (LPL) are rapidly gaining attention for a variety of applications. In this study, organic molecules with simple structures were selected and organic long persistent luminescence (OLPL) crystals were prepared. The crystal structure of the prepared OLPL crystal was elucidated and the guideline for the design of OLPL crystal was clarified. LPL was observed in OLPL crystals prepared with TMB as the guest molecule and 1,2-bis(diphenylphosphino)ethane as the host molecule. XRD measurements of the OLPL crystals suggest that the guest molecule is a solid solution substituted in the stable crystal structure of the host molecule in a lattice-shrink.ng direction.

关键词： Melt Crystallization Host-Guest Chemistry

Emotion Measurement Using Biometric Signal

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Health 2024年第5期16卷 395-404页

作者： Yuk.na Miyagi Saori Gocho Yuk. Miyachi Chik. Nak.yama Shoshiro Ok.da k.nta maruyama Taeyuk. Oshima College of Pharmacy Kinjo Gakuin University Nagoya Japan Graduate School of Medicine Aichi Medical University Nagakute Japan Department of Pharmacy Nagoya Ekisaikai Hospital Nagoya Japan Department of Pharmacy Gifu University of Medical Science Kani Japan

In recent years, research on the estimation of human emotions has been active, and its application is expected in various fields. Biological reactions, such as electroencephalography (EEG) and root mean square successive difference (RMSSD), are indicators that are less influenced by individual arbitrariness. The present study used EEG and RMSSD signals to assess the emotions aroused by emotion-stimulating images in order to investigate whether various emotions are associated with characteristic biometric signal fluctuations. The participants underwent EEG and RMSSD while viewing emotionally stimulating images and answering the questionnaires. The emotions aroused by emotionally stimulating images were assessed by measuring the EEG signals and RMSSD values to determine whether different emotions are associated with characteristic biometric signal variations. Real-time emotion analysis software was used to identify the evok.d emotions by describing them in the Circumplex Model of Affect based on the EEG signals and RMSSD values. Emotions other than happiness did not follow the Circumplex Model of Affect in this study. However, ventral attentional activity may have increased the RMSSD value for disgust as the β/θ value increased in right-sided brain waves. Therefore, the right-sided brain wave results are necessary when measuring disgust. Happiness can be assessed easily using the Circumplex Model of Affect for positive scene analysis. Improving the current analysis methods may facilitate the investigation of face-to-face communication in the future using biometric signals.

关键词： Biometric Signals Electroencephalogram Electrocardiogram Emotion Communication

Changes in lamellar microstructure by parallel twinning during creep in soft PST crystal of TiAl alloy

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中国有色金属学会会刊：英文版 2002年第4期12卷 561-568页

作者： H.Y.k.m k.maruyama DepartmentofMaterialScience GraduateSchoolofEngineeringTohokuUniversity02AobayamaSendai980－8579Japan DepartmentofMaterialScience GraduateSchoolofEngineeringTohokuUniversity02AobayamaSendai980－8

Compression creep tests of a Ti-48%Al (mole fraction) alloy were carried out at 1?150?k.with soft-orientated PST crystal. Parallel twinning took.place during the creep. Changes in lamellar microstructure caused by the parallel twinning were investigated, and their effects on creep deformation behavior were discussed. The results show that the parallel twinning occurs in an early stage of creep, and mak.s significant contribution to creep strain in the domains favorably oriented for the twinning. The nucleation of parallel twins finishes at a strain of about 3%. There is a critical resolved shear stress for parallel twinning, and it is about 50?MPa in the Ti 48%Al PST crystals at 1?150?k. The activity of parallel twinning increases with increasing applied stress or in a coarse lamellar material. The addition of parallel twins reduces the average value of lamellar spacing. In general, the refinement of lamellar structure should improve creep resistance. However the strengthening by parallel twinning is not evident in creep of the soft PST crystals because the soft deformation modes are the dominant deformation mode in the crystals.

关键词：显微结构 TiAl合金软PST晶体蠕变孪晶

Relationship between Primary Crystal Temperature and Carbon Equivalent in Cast Iron

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Journal of Materials Science & Technology 2008年第3期24卷 325-326页

作者： T.k.nno T.k.k.chi k.Hayashi Y.maruyama k.mura Chuzosho Co.Ltd. 1157 Nagasawa Shimizu-choShizuoka-ken

CE （=%C＋（1/3）x（%Si）） does not suit experiment results in many cases. In this work. the effect of alloy elements on primary crystal temperature was measured and the relationship between primary crystal temperature （Tc） and carbon equivalent （CEL） was investigated. The results show that Tc （Celsius degree） = 1650-110 × （%C） -25 × （%Si）＋3 × （%Mn） -35 × （%P） -71 × （%5）-2 × （%Ni） -7 × （%Cr）; CEL=%C ＋ 0.23×（%Si）-0.03× （%Mn）＋0.32×（%P）＋0.64×（%S）＋0.02×（%Ni）＋0.06×（%Cr）. That is, in hypo eutectic composition, carbon equivalent should be calculated with CEL=%C＋ 0.23×（%Si）, not with CE=%C＋（1/3） x（%Si）.

关键词： Carbon equivalent Cast iron Primary crystal temperature Hypo eutectic composition

Origin of the Earth:A proposal of new model called ABEL

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Geoscience Frontiers 2017年第2期8卷 253-274页

作者： Shigenori maruyama Toshik.zu Ebisuzak. Earth-Life Science Institute Tokyo Institute of Technology Institute for Study of the Earth's Interior Okayama University RIk.N

The Earth was born as a dry planet without atmosphere and ocean components at 4.56 Ga,with subsequent secondary accretion of bio-elements,such as carbon（C）,hydrogen（H）,oxygen（O）,and nitrogen（N） which peak.d at 4.37-4.20 *** two-step formation model of the Earth we refer to as the advent of bio-elements model（ABEL Model） and the event of the advent of bio-elements（water component） as ABEL *** is clear that the solid Earth originated from enstatite chondrite-lik. dry material based on the similarity in oxygen isotopic composition and among other *** the other hand,Earth＇s water derives primarily from carbonaceous chondrite material based on the hydrogen isotopic *** present our ABEL model to explain this enigma between solid Earth and water,as well as secondary accretion of oxidizing bio-elements,which became a precursor to initiate metabolism to emerge life on a highly reductive *** ABEL Bombardment had not occurred,life never would have emerged on the ***,ABEL Bombardment is one of the most important events for this planet to evolve into a habitable *** chronology of ABEL Bombardment is informed through previous researches of the late heavy bombardment and the late veneer *** Bombardment is considered to have occurred during 4.37-4.20 Ga,which is the concept to redefine the standard late heavy bombardment and the late veneer ***,ABEL Bombardment is the trigger of the transition from stagnant lid tectonics to plate tectonics on this planet because of the injection of volatiles into the initial dry Earth.

关键词： Origin of Earth and life Advent of bin-elements (ABEL)Origin of water on the Earth ABEL Bombardment Habitable Trinity planet Initiation of plate tectonics