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Discovery of a strongly r-process enhanced extremely metal-poor star LAMOST J110901.22+075441.8

Research in Astronomy and Astrophysics 2015年第8期15卷 1264-1274页

作者： Hai-Ning Li wako aoki Satoshi Honda Gang Zhao Norbert Christlieb Takuma Suda Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of Sciences National Astronomical Observatory of Japan 2-21-1 OsawaMitakaTokyo181-8588Japan Department of Astronomical Science School of Physical SciencesThe Graduate University of Advanced Studies (SOKENDAI)2-21-1 OsawaMitakaTokyo 181-8588Japan University of Hyogo Center for AstronomyNishigaichiSayo-choSayoHyogo679-5313Japan Zentrum für Astronomie der Universitt Heidelberg LandessternwarteKnigstuhl 12D-69117 HeidelbergGermany Research Center for the Early Universe The University of TokyoHongo 7-3-1Bunkyo-kuTokyo 113-0033Japan

We report the discovery of an extremely metal-poor（EMP） giant,LAMOST J110901.22＋075441.8, which exhibits a large excess of r-process elements with [Eu/Fe] ～＋1.16. The star is one of the newly discovered EMP stars identified from the LAMOST low-resolution spectroscopic survey and a highresolution follow-up observation with the Subaru Telescope. Stellar parameters and elemental abundances have been determined from the Subaru spectrum. Accurate abundances for a total of 23 elements including 11 neutron-capture elements from Sr through Dy have been derived for LAMOST J110901.22＋075441.8. The abundance pattern of LAMOST J110901.22＋075441.8 in the range of C through Zn is in line with the ＂normal＂ population of EMP halo stars, except that it shows a notable underabundance in carbon. The heavy element abundance pattern of LAMOST J110901.22＋075441.8 is in agreement with other well studied cool r-II metal-poor giants such as CS 22892-052 and CS 31082-001. The abundances of elements in the range from Ba through Dy match the scaled solar r-process pattern well.LAMOST J110901.22＋075441.8 provides the first detailed measurements of neutroncapture elements among r-II stars at such low metallicity with [Fe/H]-3.4, and exhibits similar behavior as other r-II stars in the abundance ratio of Zr/Eu as well as Sr/Eu and Ba/Eu.

关键词： star： abundances—stars： PopulationⅡ— nucleosynthesis

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Assessing efficacy of standard impregnation techniques on die-cast aluminum alloys using X-ray micro-CT

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China Foundry 2024年第3期21卷 276-286页

作者： Ajith Bandara Koichi Kan Katanaga Yusuke Natsuto Soga Akifumi Koike Toru aoki Hamamatsu TSC Chuo Hatsumei Institute322 lida-choMinami-kuHamamatsu435-0028Japan Graduate School of Medical Photonics ShizuokaUniversityJohoku 3-5-1HamamatsuShizuoka432-8561Japan ANSeeN Inc Johoku 3-5-1HamamatsuShizuoka432-8561Japan Research Institute of Electronics ShizuokaUniversityJohoku 3-5-1HamamatsuShizuoka432-8561Japan

Utilizing lightweight Al alloys in various industrial applications requires achieving precise pressure tightness and leak requirements.Vacuum pressure impregnation(VPI)with thermosetting polymers is commonly used to address leakage defects in die-cast Al alloys.In this study,the efficacy of the VPI technique in sealing alloy parts was investigated using a combination of nondestructive micro X-ray computed tomography(micro XCT)and a standard leak test.The results demonstrate that the commonly used water leak test is insufficient for determining the sealing performance.Instead,micro XCT shows distinct advantages by enabling more comprehensive analysis.It reveals the presence of a low atomic number impregnates sealant within casting defects,which has low grey contrast and allows for visualizing primary leakage paths in 3D.The effective atomic number of impregnated resin is 6.75 and that of Al alloy is 13.69 by dual-energy X-ray CT.This research findings will contribute to enhancing the standard VPI process parameters and the properties of impregnating sealants to improve quality assurance for impregnation in industrial metals.

关键词： nondestructive testing Al alloy die-casting vacuum pressure impregnation micro X-ray computed tomography duel-energy X-ray CT

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价值认知与实践决策——工业建筑遗产更新中当代建筑师的话语思考

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建筑遗产 2024年第1期 8-16页

作者：赵子杰徐苏斌田甜 [日]青木信夫天津大学建筑学院天津300072 天津大学中国文化遗产保护国际研究中心太原理工大学建筑学院

遗产的价值认知与保护是一个多维度的议题,受到不同认知主体背景差异的影响,可能引发争议,进而影响保护决策的制定。作为工业建筑遗产更新实践的直接策划者与执行者,建筑师的价值认知与实践决策会直接影响实践效果。文章旨在从建筑师的... 详细信息

遗产的价值认知与保护是一个多维度的议题,受到不同认知主体背景差异的影响,可能引发争议,进而影响保护决策的制定。作为工业建筑遗产更新实践的直接策划者与执行者,建筑师的价值认知与实践决策会直接影响实践效果。文章旨在从建筑师的价值认知视角出发,记录这一群体对价值认知与保护决策的思考,以探究建筑师群体对于遗产保护与再利用的当代思考。文章发现,建筑师群体普遍认为工业建筑遗产要走入当代生活,并对工业建筑遗产及其环境的保护利用和干预持正面态度。

关键词：工业建筑遗产更新建筑师价值认知

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Camel management as an adaptive strategy to climate change by pastoralists in southern Ethiopia

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Ecological Processes 2017年第1期6卷 273-284页

作者： Galma wako Menfese Tadesse Ayana Angassa Wondo-Genet College of Forestry and Natural Resource Hawassa UniversityShashamaneEthiopia Department of Animal Science and Production Botswana University of Agriculture and Natural ResourcesGaboroneBotswana

Introduction:Experiences of low rainfall and frequent droughts have had enormous impacts on livestock production and pastoralists’livelihoods in southern Ethiopia.The Borana pastoralists are dependent on livestock husbandry with the dominance of cattle in their herds for generations.Recently,the Borana communities have engaged in extensive livestock species diversification,with more focus on camel management as an adaptation strategy to the severity of recurrent droughts.Although increasing interests in camel management among the Borana pastoralists are acknowledged,the driving forces for the increase in camel population in the region have not been addressed.The aim of this study was to assess the trend in camel management as an adaptation strategy towards climate change among the Borana pastoral households.The study also investigated evidence of climate change and the driving factors for camel adoption.Methods:The study was conducted in three purposively selected kebeles,which is a lower administrative unit in Ethiopia,of Yabello district in Borana Zone in southern Ethiopia focusing on 156 randomly selected camel-owning households.The study employed both quantitative and qualitative methods whereby data gathering tools such as key informant interviews(KII),focus group discussions(FGD),household surveys(HS),and field observations were used.The data were analyzed by descriptive statistics using SPSS software version 16.Results:Pastoralists’perceptions and the existing meteorological data analysis showed an increasing trend in temperature but a decreasing pattern in rainfall over the last 27 years(i.e.,during the last four Gada periods).Both pastoralists’observations and existing meteorological data analysis showed an increasing incidence of recurrent droughts with decreasing availability of grazing and water resources.Respondents further explained that cattle are more vulnerable during severe droughts.The findings also showed that camel management as an adaptation strategy by the Borana pastoralists began recently

关键词： Climate change Camel management Pastoral households Borana Zone Southern Ethiopia

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Eustachian tube involvement in a patient with relapsing polychondritis detected by magnetic resonance imaging:A case report

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World Journal of Clinical Cases 2022年第4期10卷 1441-1446页

作者： Daisuke Yunaiyama Akiko aoki Hiroshi Kobayashi Miwako Someya Mitsuru Okubo Kazuhiro Saito Department of Radiology Tokyo Medical University HospitalShinjuku-ku 160-0023TokyoJapan Department of Radiology Tokyo Medical University Hachioji Medical CenterHachioji-shi 193-0998Japan Department of Rheumatology Tokyo Medical University Hachioji Medical CenterHachioji-shi 193-0998Japan Department of Otorhinolaryngology Head and Neck SurgeryTokyo Medical University Hachioji Medical CenterHachioji-shi 193-0998Japan

BACKGROUND Relapsing polychondritis(RP)is a rare inflammatory disease involving the systemic cartilage,such as the auricle,trachea,and bronchiole,among others.A patient with RP shows variable symptoms based on the involved cartilage.CASE SUMMARY A 72-year-old Japanese woman with a history of redness of the bilateral auricles for 3 d was referred to a clinician.The clinician prescribed antibiotics to the patient;however,the symptoms worsened;thus,she was referred to our hospital.Head and neck magnetic resonance imaging(MRI)showed edematous auricle with remarkable contrast,fluid collection in the bilateral mastoid cells,suggesting otitis media.The eustachian tube(ET)on the right side was also edematous with contrast enhancement.The patient was suspected of RP according to the diagnostic criteria.A biopsy of the auricular cartilage was performed by an otorhinolaryngologist,confirming pathological proof of RP.Treatments with steroids were immediately administered thereafter.CONCLUSION We highlight a rare case of RP with radiologically confirmed involvement of ET in the MRI.

关键词： Relapsing polychondritis Magnetic resonance imaging Contrast enhancement Otitis media with effusion Eustachian tube Case report

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Combustion synthesis, characterization and luminescence properties of barium aluminate phosphor

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Journal of Rare Earths 2014年第9期32卷 806-811页

作者： A.H. wako F.B Dejene H.C Swart Department of Physics University of the Free State (Qwaqwa Campus) Department of Physics University of the Free State

The blue-green emitting Eu2＋ and Nd3＋ doped polycrystalline barium aluminate （BaAI204：Eu2＋,Nd3＋） phosphor, was prepared by a solution-combustion method at 500 ℃without a post-annealing process. The characteristic variation in the structural and luminescence properties of the as-prepared samples was evaluated with regards to a change in the Ba/A1 molar ratio from 0.1：1 to 1.4：1. The morphologies and the phase structures of the products were characterized by scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, X-ray diffraction （XRD） and X-ray photoelectron spectroscopy （XPS）, while the optical properties were investigated using ultra-violet （UV） and photoluminescence （PL） spectroscopy, respectively. The XRD and TEM results revealed that the average crystallite size of the BaAl2O4：Eu2＋,Nd3＋ phosphor was about 70 urn. The broad-band UV-excited luminescence of the phosphors was observed at 2max=500 um due to transitions from the 4f^65d1 to the 4f7 configuration of the Eu2＋ ion. The PL results indicated that the main peaks in the emission and excitation spectrum of phosphor particles slightly shifted to the short wavelength due to the changes in the crystal field due to the structure changes caused by the variation in the quantity of the Ba ions in the host lattice.

关键词： BaAl2O4：Eu2＋,Nd3＋ persistence luminescence Eu2＋ and Nd3＋ doping rare earths

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Effect of hydrogen peroxide on selective flotation of chalcocite and enargite

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International Journal of Mining Science and Technology 2023年第6期33卷 703-716页

作者： Gde Pandhe Wisnu Suyantara Daniyarov Berdakh Hajime Miki Tsuyoshi Hirajima Keiko Sasaki Daishi Ochi Yuji aoki Department of Earth Resources Engineering Faculty of EngineeringKyushu UniversityFukuoka 819-0395Japan Kyushu University Institute for Asian and Oceanian Studies Kyushu UniversityFukuoka 819-0395Japan Graduate School of Engineering Faculty of EngineeringKyushu UniversityFukuoka 819-0395Japan Uzbekistan-Japan Innovation Center of Youth Tashkent 100095Uzbekistan Sumitomo Metal Mining Co. Ltd.Tokyo 105-8716Japan Sumitomo Metal Mining Co. Ltd.Ehime 792-0002Japan

Enargite is typically associated with chalcocite.Owing to the similarity in the flotation behaviors of these minerals,both minerals are reported to concentrate in the conventional flotation circuit.However,inorganic arsenic in enargite can decrease the copper concentrate quality and increase the operating cost of processing this concentrate.Separating these minerals is important for cleaner copper production to avoid these effects.In this context,this study investigated the effect of hydrogen peroxide(H_(2)O_(2))treatment on the flotation behavior of chalcocite and enargite.Flotation tests of pure and mixed minerals indicated that H_(2)O_(2)treatment reduced the floatability of chalcocite and enargite by forming sulfate and copper hydroxide on their surfaces.Despite the detrimental effect of the H_(2)O_(2)treatment,there was a narrow window of H_(2)O_(2)concentration for separating both minerals,in which enargite floated and chalcocite was depressed.This selective flotation behavior was caused by the rapid adsorption of potassium amyl xanthate(KAX)and lower surface oxidation of enargite compared with that of chalcocite.

关键词： Enargite Chalcocite Hydrogen peroxide Potassium amyl xanthate Selective flotation

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Flat friction spot joining of aluminum alloy to carbon fiber reinforced polymer sheets:Experiment and simulation

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Journal of Materials Science & Technology 2022年第12期107卷 266-289页

作者： Peihao Geng Ninshu Ma Hong Ma Yunwu Ma Kazuki Murakami Huihong Liu Yasuhiro aoki Hidetoshi Fujii Joining and Welding Research Institute Osaka University11-1 MihogaokaOsaka 567-0047IbarakiJapan MOE Key Lab for Liquid-Solid Structure Evolution and Material Processing Institute of Materials JoiningShandong UniversityJinan 250061China

The Al alloy and carbon fiber reinforced polymer(CFRP)hybrid structures,incorporating the performance advantages of the two materials,have been attracting more attention in high-end manufacturing fields.In the current investigation,the flat friction spot joining(FSJ)was employed in joining the AA6061-T6 alloy and CFRP sheets.The significance of temperature distribution in influencing joint quality was highlighted through analyzing interface microstructural features,weld defect formation as well as fractography.To understand the role of thermal energy generation and conduction in the process comprehensively,a 3D thermal-mechanical coupling finite element model was established.The interfacial temperature was characterized by an uneven distribution behavior due to the inhomogeneous heat distribution.The peak temperatures on the top surface and Al alloy to CFRP interface at 1500 rpm rotational speed with 0.1 mm/s plunging speed were 498℃and 489°C,respectively.The peak interface temperature was reduced to286℃at 250 rpm,which produced an extremely small melted area.Compared with the plunging speed,rotational speed was found to be the predominant parameter for determining the joint property,which could be optimized to simultaneously realize the avoidance of thermal decomposition of CFRP,the sufficient melting duration time,and the wide enough melted area.Simulated thermal histories and melted area profiles were in agreement with experimental ones.The findings could be utilized to provide some feasible guidance for process optimization of dissimilar FSJ of metals and composites.

关键词： Friction spot joining Numerical simulation CFRP/Al alloy Interface microstructure Thermal conduction

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Principle for obtaining high joint quality in dissimilar friction welding of Ti-6Al-4V alloy and SUS316L stainless steel

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Journal of Materials Science & Technology 2020年第11期42卷 211-224页

作者： Huihong Liu Yo aoki Yasuhiro aoki Kohsaku Ushioda Hidetoshi Fujii Joining and Welding Research Institute Osaka UniversityIbarakiOsaka 567-0047Japan

Ti-6Al-4V alloy(Ti64)and SUS316 L stainless steel rods were dissimilarly friction welded.Especially focusing on the detailed observation of interface microstructural evolution during the friction welding(FW),the relationship between the processing conditions,weld interface microstructure,and mechanical properties of the obtained joints were systematically investigated to elucidate the principle for obtaining a high joint quality in the FW of Ti64 and SUS316L.A higher friction pressure produced a lower welding temperature in the FW,hence suppressing the thick intermetallic compound layer formation.However,hard and brittle Ti64/SUS316L mechanically mixed layers generally formed especially at the weld interface periphery due to the high temperature increasing rate,high rotation linear velocity and high outward flow velocity of the Ti64.These harmful layers tended to induce the cracks/voids formation at the weld interfaces hence deteriorating the joints’mechanical properties.The rotation speed reduction and liquid CO2 cooling during the entire processing decreased the temperature increasing rate,rotation linear velocity and outward flow velocity of the Ti64 at the weld interface periphery.Therefore,they suppressed the formation of the harmful mechanically mixed layers,facilitated the homogeneous and sound interface microstructure generation,and finally produced a high-quality dissimilar joint in the FW of Ti64 and SUS316L.

关键词： Friction welding Titanium alloy Stainless steel Microstructure formation mechanism Mechanically mixed layers

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Functional layer engineering to improve performance of protonic ceramic fuel cells

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Rare Metals 2023年第7期42卷 2250-2260页

作者： Ning Wang Zhi-Yin Huang Chun-Mei Tang Li-Xin Xing Ling Meng Yoshitaka aoki Lei Du Si-Yu Ye Huangpu Hydrogen Energy Innovation Center School of Chemistry and Chemical EngineeringGuangzhou UniversityGuangzhou510006China Graduate School of Chemical Sciences and Engineering Hokkaido UniversitySapporo060-8628Japan Faculty of Engineering Hokkaido UniversitySapporo060-8628Japan

Protonic ceramic fuel cells(PCFCs)have been attracting increasing attention because of their advances in high-efficiency power generation in an intermediate-temperature range,as compared to the high-temperature solid oxide fuel cells(SOFCs).The greatest difference between PCFCs and SOFCs is the specific requirement of protonic(H+)conductivity at the PCFC cathode,in addition to the electronic(e^(-))and oxide-ion(O^(2-))conductivity.The development of a triple H^(+)/e^(-)/O^(2-)conductor for PCFC cathode is still challenging.Thus,the most-widely used cathode material is based on the mature e^(-)/O^(2-)conductor.However,this leads to insufficient triple phase boundary(TPB),i.e.,reaction area.Herein,an efficient strategy that uses a~100 nm-thick proton conductive functional layer(La_(0.5)Sr_(0.5)CoO_(3-δ),LSC55)in-between the typical La_(0.8)Sr_(0.2)CoO_(3-δ)cathode(a mature e-/O^(2-)conductor,LS C 82)and B aZr_(0.4)Ce_(0.4)Y_(0.1)Yb_(0.)1O_(3-δ)elec trolyte(11 mm in diameter,20μm in thickness)is proposed to significantly enhance the reaction area.Reasonably,the ohmic resistance and polarization resistance are both decreased by 47%and 62%,respectively,compared with that of PCFCs without the functional layer.The power density of the PCFC with such a functional layer can be raised by up to 2.24 times,superior to those described in previous reports.The enhanced PCFC performances are attributed to the well-built TPB and enhanced reaction area via the functional layer engineering strategy.

关键词： Protonic ceramic fuel cell(PCFC) Cathode functional layer(CFL) Power density Triple phase boundary(TPB)

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