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Stellar population analysis on the stacked spectra of double-peaked emission-line galaxies

Research in Astronomy and Astrophysics 2019年第9期19卷 37-54页

作者： meng-xin wang A-Li Luo National Astronomical Observatories Chinese Academy of SciencesBeijing100101China University of Chinese Academy of Sciences Beijing100049China Department of Physics and Astronomy University of DelawareNewarkDE19716USA

Double-peaked emission-line galaxies have long been perceived as objects related to merging galaxies or other phenomena with disturbed dynamical activities, such as outflows and disk rotation. In order to find the connection between the unique activities happening in these objects and their stellar population physics, we study the stellar populations of the stacked spectra drawn from double-peaked emission-line galaxies in the Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST) Data Release 4(DR4) and the Sloan Digital Sky Survey(SDSS) Data Release 7(DR7) databases. We group the selected double-peaked emission-line objects into 10 different types of pairs based on the Baldwin-Phillips-Terlevich(BPT) diagnosis for each pair of blueshifted and redshifted components, and then stack the spectra of each group for analysis. The software STARLIGHT is employed to fit each stacked spectrum, and the contributions of stars at different ages and metallicities are quantified for subsequent comparative study and analysis. To highlight the commonality and uniqueness in these double-peaked emitting objects, we compare the population synthesis results of the stacked spectra of double-peaked emission-line galaxies with those of their counterpart reference samples displaying single-peaked emission features. The reference samples are also selected from the LAMOST DR4 and SDSS DR7 databases. From the comparison results,we confirm the strong correlations between stellar populations and their spectral classes, and find that the double-peaked emitting phenomenon is more likely to occur in an ‘older’ stellar environment and the subgroups hosting different BPT components will show an obvious heterogeneous star formation history.

关键词： galaxies:evolution galaxies:stellar content

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Microstructure and mechanical properties of a cast TRIP-assisted multiphase stainless steel

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China Foundry 2024年第3期21卷 221-228页

作者： meng-xin wang Zi-xiang Wu Jing-yu He Xiang Chen School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China Key Laboratory for Advanced Materials Processing Technology Ministry of EducationBeijing 100084China

Stainless steels are used in a wide range of complex environments due to their excellent corrosion *** stainless steels can offer an excellent combination of strength,toughness and corrosion resistance due to the coexistence of different *** microstructure and mechanical properties of a novel cast multiphase stainless steel,composed of martensite,ferrite,and austenite,were investigated following appropriate heat treatment processes:solution treatment at 1,050℃ for 0.5 h followed by water quenching to room temperature,and aging treatment at 500℃ for 4 h followed by water quenching to room *** show reversed austenite is formed by diffusion of Ni element during aging process,and the enrichment of Ni atoms directly determines the mechanical stability of *** austenite with a lower Ni content undergoes a martensitic transformation during plastic *** tensile strength of the specimen exceeds 1,100 MPa and the elongation exceeds 24%after solid solution,and further increases to 1,247 MPa and 25%after aging *** enhancement is due to the TRIP effect of austenite and the precipitation of the nanoscale G-phase pinning dislocations in ferrite and martensite.

关键词： multiphase stainless steel mechanical properties TRIP effect reversed austenite G-phase

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A peptide-based near-infrared fluorescence probe for dynamic monitoring senile plaques in Alzheimer＇s disease mouse model

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Science Bulletin 2017年第23期62卷 1593-1601页

作者： Chen-Wei wang Dou-Dou Nan xin-meng wang zun-Ji Ke Guo-Jun Chen Jiang-Ning Zhou CAS Key Laboratory of Brain Function and Disease School of Life Sciences University of Science and Technology of China Hefei 230026 China Department of Biochemistry Shanghai University of Traditional Chinese Medidne Shanghai 201203 China Department of Neurology The First Affiliated Hospital of Chongqing Medical University Chongqing Key Laboratory of Neurology Chongqing 400016 China

In vivo monitoring neuropathological changes in Alzheimer＇s disease （AD） animal model is critical for drug development. Here, by integrating blood-brain barrier penetrable peptide, we have developed a peptide probe which based on angiopep-2. Angiopep-based probe exhibited high binding affinity to Aβ aggregates and labeled senile plaques in vivo. Remarkably, the in vivo near-infrared imaging data revealed that fluorescence signals of this probe were nearly 3-fold higher in the brains of 16-monthold APP/PSI transgenic mice compared to C57 mice and exhibited linear correlation with the senile plaques load process in 4-, 8-, 16-month-old APP/PSI transgenic mice. Moreover, senile plaques load was detected in vivo as early as 4 months of age that even at the very beginning of plaques developed in APP/PS1 transgenic mice. Taken together, this novel peptide-based probe achieved dynamic monitoring senile plaques in APP/PS1 transgenic mice and have been ready to use in drug development in AD mouse model.

关键词： Alzlaelmer's diseaseSenile plaquesAmyloid-β LRP-1 Angiopep In vivo imaging AD animal model

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Metal-slag separation strengthening through in situ slagging during CuW composite preparation by metallothermic reduction

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Rare Metals 2024年第11期43卷 6113-6121页

作者： Chu Cheng xin-Yu wang Ting-An Zhang Zhi-He Dou Ke-xing Song meng-xin wang Yan-Shuo Feng Tao Huang Hai-Tao Liu Xiao-Heng Li Kai Li School of Materials Science and Engineering Henan University of Science and TechnologyLuoyang 471023China Provincial and Ministerial Co-Construction of Collaborative Innovation Center for Non-Ferrous Metal New Materials and Advanced Processing Technology Luoyang 471023China Henan Key Laboratory of Non-Ferrous Materials Science&Processing Technology Henan University of Science and TechnologyLuoyang 471003China Key Laboratory of Ecological Utilization of Multi-Metal Intergrown Ores of Ministry of Education Northeastern UniversityShenyang 110819China Henan Key Laboratory of Advanced Conductor Materials Institute of MaterialsHenan Academy of Sciences Henan Academy of SciencesZhengzhou 450002China Henan Zhongyuan Gold Smelter. LLCSanmenxia 472100China Henan Pinggao Electric Co. LTDPingdingshan 467000China

CuW is widely used in high-voltage electrical switch contacts,rocket nozzle throat linings,electronic packaging materials and other major high-end *** is typically fabricated using infiltration and high-temperature sintering methods based on powder *** CuW composites fabricated using these methods have the disadvantages of low density and uneven microstructural distribution,the preparation of CuW composites by alu-minothermic reduction was proposed.

关键词： composites composite preparation

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Behavioral responses for evaluating the attractiveness of specific tea shoot volatiles to the tea green leafhopper, Empoaca vitis

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Insect Science 2012年第2期19卷 229-238页

作者： Dan Mu Lin Cui Jian Ge meng-xin wang Li-Fang Liu Xiao-Ping Yu Qing-He Zhang Bao-Yu Han Tea Research Institute of Chinese Academy of Agricuitural Sciences Zhejiang Provincial Key Laboratory of Biometrology and Inspection&Quarantine College of Life Sciences of China Jiliang UniversityHangzhouChina Sterling International Inc.SpokaneWAUSA

The tea green leafhopper, Empoasca vitis Gothe, is one of the most serious insect pests of tea plantations in China's Mainland. Over the past decades, this pest has been controlled mainly by spraying pesticides. Insecticide applications not only have become less effective in controlling damage, but even more seriously, have caused high levels of toxic residues in teas, which ultimately threatens human health. Therefore, we should seek a safer biological control approach. In the present study, key components of tea shoot volatiles were identified and behaviorally tested as potential leafhopper attractants. The following 13 volatile compounds were identified from aeration samples of tea shoots using gas chromatography-mass spectrometry （GC-MS）：（E）-2-hexenal, （Z）-3-hexen-1- ol, （Z）-3-hexenyl acetate, 2-ethyl-1-hexanol, （E）-ocimene, linalool, nonanol, （Z）-butanoic acid, 3-hexenyl ester, decanal, tetradecane, β-caryophyllene, geraniol and hexadecane. In Y-tube olfactometer tests, the following individual compounds were identified：（E）-2- hexenal, （E）-ocimene, （Z）-3-hexenyl acetate and linalool, as well as two synthetic mixtures （called blend 1 and blend 2） elicited significant taxis, with blend 2 being the most attractive. Blend 1 included linalool, （Z）-3-hexen-l-ol and （E）-2-hexenal at a 1： 1：1 ratio, whereas blend 2 was a mixture of eight compounds at the same loading ratio：（E）-2-hexenal, （Z）- 3-hexen-l-ol, （Z）-3-hexenyl acetate, 2-penten-l-ol, （E）-2-pentenal, pentanol, hexanol and 1-penten-3-ol. In tea fields, the bud-green sticky board traps baited with blend 2, （E）-2- hexenal or hexane captured adults and nymphs of the leafhoppers, with blend 2 being the most attractive, foUowed by （E）-2-hexenal and hexane. Placing sticky traps baited with blend 2 or （E）-2-hexenal in the tea fields significantly reduced leathopper populations. Our results indicate that the bud-green sticky traps baited with tea shoot volatiles can provide a new tool for monitoring and managing the

关键词： attractant behavior green leaf volatiles tea green leafhopper tea shoot volatiles

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The origin of sulfuryl-containing components in SEI from sulfate additives for stable cycling of ultrathin lithium metal anodes

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Journal of Energy Chemistry 2020年第8期29卷 128-131,I0005页

作者： Jin-Xiu Chen Xue-Qiang Zhang Bo-Quan Li xin-meng wang Peng Shi Wancheng Zhu Aibing Chen Zhehui Jin Rong Xiang Jia-Qi Huang Qiang Zhang Department of Chemical Engineering Qufu Normal UniversityQufu 273165ShandongChina Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Department of Chemical Engineering Tsinghua UniversityBeijing 100084China College of Chemical and Pharmaceutical Engineering Hebei University of Science and TechnologyShijiazhuang 050018HebeiChina School of Mining and Petroleum Engineering Department of Civil and Environmental EngineeringUniversity of AlbertaEdmontonAB T6G 1H9Canada Department of Mechanical Engineering The University of TokyoTokyo 113-8656Japan Advanced Research Institute of Multidisciplinary Science Beijing Institute of TechnologyBeijing 100081China

In the light of wireless and non-fossil society based on portable electronics, electric vehicles, and smart grids, secondary batteries with higher energy density, faster charge, and safer operation are pursued persistently [1]. Nowadays, commercial lithium(Li)-ion batteries have been practically applied in our daily life. However,the energy density of Li-ion batteries based on intercalation chemistry is approaching to the theoretical value due to the limited specific capacity of graphite anode(372 mA h g-1) [2].

关键词： Ultrathin lithium anodes Dendrites Electrolyte additives Solid electrolyte interphase Lithium batteries

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M Dwarf catalog of LAMOST general survey data release one

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Research in Astronomy and Astrophysics 2015年第8期15卷 1182-1196页

作者： Yan-xin Guo Zhen-Ping Yi A-Li Luo You-Fen wang Yu Bai Hai-Feng Yang Yi-Han Song Jian-Jun Chen Xiao-Yan Chen Fang Zuo Bing Du Jian-Nan Zhang Yin-Bi Li Xiao Kong meng-xin wang Yue Wu Ke-Fei Wu Yong-Heng Zhao Yong Zhang Yong-Hui Hou Yue-Fei wang Ming Yang Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of Sciences University of Chinese Academy of Sciences School of Mechanical Electical & Information EngineeringShandong University at Weihai School of Computer Science and Technology Taiyuan University of Science and Technology Nanjing Institute of Astronomical Optics & Technology National Astronomical ObservatoriesChinese Academy of Sciences

We present a spectroscopic catalog of 93 619 M dwarfs from the first data release of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope（LAMOST）general survey. During sample selection, M giant contamination was eliminated using2 MASS photometry and Ca H/TiO molecular indices. For each spectrum, the spectral subtype and values are provided including radial velocity, Hα equivalent width, a series of prominent molecular band indices, and the metal–sensitive parameter ζ, as well as distances and the space motions for high S/N objects. In addition, Hα emission lines are measured to examine the magnetic activity properties of M dwarfs and 7179 active ones are found. In particular, a subsample with significant variation in magnetic activity is revealed through observations from different epochs. Finally, statistical analysis for this sample is performed, including the metallicity classification, the distribution of molecular band indices and their errors.

关键词： catalogs—methods: analytical—stars: statistical—stars : late-type—stars: magnetic-activity—stars

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Nearby M subdwarfs from LAMOST data release 2

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Research in Astronomy and Astrophysics 2016年第7期16卷 55-68页

作者： Yu Bai A-Li Luo Georges Comte Jing-Kun Zhao Hai-Feng Yang Yan-xin Guo You-Fen wang Yin-Bi Li Bing Du Wen Hou Xiao Kong Zhen-Ping Yi Yi-Han Song Zhong-Rui Bai Jian-Nan Zhang meng-xin wang Jian-Jun Chen Xiao-Yan Chen Ke-Fei Wu Fang Zuo Yue Wu Zi-Huang Cao Yong-Hui Hou Yue-Fei wang Yong Zhang Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing100012 China University of Chinese Academy of Sciences Beijing 100049 China Aix-Marseille University CNRS Institut Pytheas L.A.M. UMR 7326 13388 Marseille Cedex France School of Computer Science and Technology Taiyuan University of Science and Technology Taiyuan 030024 China School of Mechanical Electrical & Information Engineering Shandong University at Weihai Weihai 264209 China Nanjing Institute of Astronomical Optics & Technology National Astronomical Observatories Chinese Academy of Sciences Nanjing 210042 China

We identify 108 M subdwarfs（sd Ms） out of more than two hundred thousand M type spectra from the second data release（DR2） of the LAMOST regular survey. This sample, among which 58 members are identified for the first time, includes 33 extreme subdwarfs（esd Ms） and 11 ultra subdwarfs（usd Ms）.The selection is based on the usual ratio of absorption depth of Ca H2, Ca H3 and TiO 5 band *** also emphasize the use of the Ca H1 band. We provide estimates of spectral subtype（SPT）, L′epine metallicity index ζ, effective temperature and [Fe/H]. Both ζ–[Fe/H] and SPT–Teff figures show reasonable consistency; compared to PHOENIX model spectra, average rounded values of [Fe/H] for sd Ms, esd Ms and usd Ms are respectively –0.5, –1 and –1.5. The photometric distances are estimated, indicating that most sources are located within 500 pc of the Sun and 350 pc of the Galactic disk. Velocities and 3D Galactic motions are also briefly discussed. Among the 108 subdwarfs, seven stars appear to be active with a significant Hα emission line. The source LAMOST J104521.52＋482823.3 is a white dwarf- M subdwarf binary, while LAMOST J123045.52＋410943.8, also active, exhibits carbon features in red.

关键词： stars late-type stars statistics subdwarfs

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铝、铁、钛3种金属盐基混凝剂调理污泥的性能比较

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环境科学 2018年第5期39卷 2274-2282页

作者：王晓萌王鑫杨明辉张淑娟南京大学环境学院污染控制与资源化研究国家重点实验室南京210023

以铝盐、铁盐和钛盐混凝剂为研究对象,重点比较了3种混凝剂的污泥调理性能.通过测定调理前后污泥比阻、胞外聚合物中蛋白质和多糖的含量变化,结合三维荧光光谱与分子量变化分析及调理前后污泥尺寸大小与颗粒表面形貌变化,系统比较了它... 详细信息

以铝盐、铁盐和钛盐混凝剂为研究对象,重点比较了3种混凝剂的污泥调理性能.通过测定调理前后污泥比阻、胞外聚合物中蛋白质和多糖的含量变化,结合三维荧光光谱与分子量变化分析及调理前后污泥尺寸大小与颗粒表面形貌变化,系统比较了它们对污泥的调理性能,并揭示了调理机制.3种无机混凝剂的污泥调理能力依次为:聚合氯化铝(PAC)、钛凝胶混凝剂(TXC)、聚合硫酸铁(PFS);调理后,污泥胞外聚合物中蛋白质和多糖含量明显降低;PFS和TXC对有机物的结合能力要强于PAC,疏松结合的胞外聚合物中多糖含量是影响污泥脱水性能的关键因素;调理过程中3种混凝剂所形成污泥颗粒的大小顺序为:TXC>PFS>PAC,所形成污泥颗粒的大小并非影响污泥脱水性能的关键因素,无机混凝剂电中和能力和与有机物的络合能力共同影响无机混凝剂的污泥调理性能.本研究为污泥调理混凝剂的选取提供了实验和理论依据.

关键词：污泥调理无机混凝剂钛凝胶胞外聚合物调理机制

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大张角聚焦换能器中的张角变化对生物组织温度场的影响

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南京大学学报（自然科学版） 2017年第1期53卷 114-121页

作者：戚萌王鑫刘晓宙近代声学教育部重点实验室南京大学声学研究所南京210093

高强度聚焦超声(HIFU)是现代医学肿瘤治疗物理疗法的一项重要技术,其原理是通过聚焦方法将大面积超声聚焦换能器辐射出的声能量汇聚于面积极小的聚焦区,使聚焦区获得较强的声能量并利用超声波的热效应在短时间内使病灶部位获得较高的温... 详细信息

高强度聚焦超声(HIFU)是现代医学肿瘤治疗物理疗法的一项重要技术,其原理是通过聚焦方法将大面积超声聚焦换能器辐射出的声能量汇聚于面积极小的聚焦区,使聚焦区获得较强的声能量并利用超声波的热效应在短时间内使病灶部位获得较高的温升,从而使肿瘤组织热凝固坏死.大张角聚焦换能器指的是球面半张角大于16.6°的球壳式聚焦换能器.相对于传统的小张角换能器,大张角聚焦换能器拥有更强的声聚焦效应,聚焦区半径更小,穿透性更好,声能量聚焦效果明显强于小张角换能器,所以可以获得更好的温升.利用Spheroidal Beam Equation(SBE)方程求解大张角聚焦换能器条件下的声场获得空间热源的产热率,然后通过Pennes方程解出大张角聚焦换能器条件下生物组织中的温度场分布.研究不同改变张角方式下大张角聚焦换能器作用下生物组织的温升分布情况,研究结果表明改变换能器的孔径以改变张角时,张角越大温升越大,而改变其焦距以改变张角时,温度变化则相反.实验也验证了换能器孔径变化对生物组织中的温升的影响.

关键词： Spheroidal Beam Equation(SBE)方程 Pennes方程大张角聚焦换能器温度场

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