检索结果-内蒙古大学图书馆

Electronic and spin structure of O- and H-adsorbed Fe3O4(111) surfaces

Physical Review B 2019年第8期99卷 085442-085442页

作者： Kanta Asakawa Yoshio Miura Naoki Nagatsuka Kotaro Takeyasu Masuaki Matsumoto Katsuyuki Fukutani Institute of Industrial Science The University of Tokyo 4-6-1 Komaba Meguro-Ku Tokyo 153-8505 Japan Electrical Engineering and Electronics Kyoto Institute of Technology Matsugasaki Sakyo-ku Kyoto 606-8585 Japan Research Center for Magnetic and Spintronic Materials National Institute for Materials Science 1-2-1 Sengen Tsukuba Ibaraki 305-0047 Japan Natural Science Division Tokyo Gakugei University Koganei Tokyo 184-8501 Japan Advanced Science Research Center Japan Atomic Energy Agency (JAEA) Tokai Ibaraki 319-1195 Japan

The adsorption of O and H atoms on the Fe3O4(111) surface was investigated using ultraviolet photoemission spectroscopy (UPS) and first-principles calculations. On the FeA1-terminated surface, H adsorption decreases the work function without changing the density of states near the Fermi level. The density of states near the Fermi level decreases by O adsorption. On the O/FeA1-terminated surface, H adsorption dramatically increases the density of states near the Fermi level, indicating that the Fe 3d state is modified. The first-principles calculations showed that the electronic structure of the surface FeA on the FeA1-terminated surface is half metallic with its spin up forming an isolated spin-polarized conductive layer. By O adsorption, the up-spin band at the Fermi level of the surface FeA site is removed, and the Fermi level of the surface FeA moves to the down-spin t2g band. By subsequent H adsorption, electrons are doped to the FeA1 site, and the surface FeA1 layer becomes semiconducting. These results indicate that the charge and spin structure is modulated by O and H adsorption.

关键词： Adsorption Spin polarization Surface states Ferrites Half-metals First-principles calculations Ultraviolet photoelectron spectroscopy

来源：评论

学校读者我要写书评

暂无评论

Word2Cluster: A New Multi-Label Text Clustering Algorithm with an Adaptive Clusters Number

Word2Cluster: A New Multi-Label Text Clustering Algorithm wi...

引用

2019 IEEE Global Communications Conference (GLOBECOM)

作者： Kaili Mao Jianwei Niu Xuefeng Liu Shui Yu Longbo Zhao State Key Laboratory of Virtual Reality Technology and Systems School of Computer Science and Engineering Beihang University Beijing China Beijing Advanced Innovation Center for Big Data and Brain Computing (BDBC) Beihang University Hangzhou Innovation Research Institute Beihang University School of Computer Science and Cyber Engineering Guangzhou University Guangdong China China aerospace science and industry corporation China

ISBN: (数字)9781728109626

ISBN: (纸本)9781728109633

Text clustering has been widely used in many Natural Language Processing (NLP) applications such as text summarization and news recommendation. However, most of the current algorithms need to predefine a clustering number, which is difficult to obtain. Moreover, the mutli-label clustering is useful in multiple clustering tasks in many applications, but related works are rarely available. Although several studies have attempted to solve above two problems, there is a need for methods that can solve the two issues simultaneously. Therefore, we propose a new text clustering algorithm called Word2Cluster. Word2Cluster can automatically generate an adaptive number of clusters and support multi-label clustering. To test the performance of Wrod2Cluster, we build a Chinese text dataset, Hotline, according to real world applications. To evaluate the clustering results better, we propose an improved evaluation method based on basic accuracy, precision and recall for multi-label text clustering. Experimental results on a Chinese text dataset (Hotline) and a public English text dataset (Reuters) demonstrate that our algorithm can achieve better F1-measure and runs faster than the state-of- the-art baselines.

关键词： Clustering algorithms Biological system modeling Merging Task analysis computer science Technological innovation Natural language processing

来源：评论

学校读者我要写书评

暂无评论

Discovery of dual "little red dots" indicates excess clustering on kilo-parsec scales

arXiv

引用

arXiv 2024年

作者： Tanaka, Takumi S. Silverman, John D. Shimasaku, Kazuhiro Arita, Junya Akins, Hollis B. Inayoshi, Kohei Ding, Xuheng Onoue, Masafusa Liu, Zhaoxuan Casey, Caitlin M. Lambrides, Erini Kokorev, Vasily Jin, Shuowen Faisst, Andreas L. Drakos, Nicole Shen, Yue Li, Junyao Zhuang, Mingyang Fei, Qinyue Ito, Kei Ren, Wenke Matsui, Suin Ando, Makoto Hatano, Shun Fujii, Michiko S. Kartaltepe, Jeyhan S. Koekemoer, Anton M. Liu, Daizhong McCracken, Henry Joy Rhodes, Jason Robertson, Brant E. Franco, Maximilien Andika, Irham T. Cloonan, Aidan P. Fan, Xiaohui Gozaliasl, Ghassem Harish, Santosh Hayward, Christopher C. Huertas-Company, Marc Kakkad, Darshan Kinugawa, Tomoya Roy, Namrata Shuntov, Marko Talia, Margherita Toft, Sune Vijayan, Aswin P. Zhang, Yiyang The University of Tokyo Institutes for Advanced Study The University of Tokyo Kashiwa Chiba277-8583 Japan Department of Astronomy Graduate School of Science The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo113-0033 Japan UTIAS The University of Tokyo Kashiwa Chiba277-8583 Japan Center for Astrophysical Sciences Department of Physics and Astronomy Johns Hopkins University BaltimoreMD21218 United States Research Center for the Early Universe Graduate School of Science The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo113-0033 Japan Department of Astronomy The University of Texas at Austin 2515 Speedway Boulevard Stop C1400 AustinTX78712 United States Kavli Institute for Astronomy and Astrophysics Peking University Beijing100871 China School of Physics and Technology Wuhan University Wuhan430072 China Denmark NASA-Goddard Space Flight Center Code 662 GreenbeltMD20771 United States Kapteyn Astronomical Institute University of Groningen Groningen9700 AV Netherlands DTU Space Technical University of Denmark Elektrovej Building 328 Kgs. Lyngby2800 Denmark Caltech/IPAC 1200 E. California Blvd PasadenaCA91125 United States Department of Physics and Astronomy University of Hawaii Hilo 200 W Kawili St. HiloHI96720 United States Department of Astronomy University of Illinois at Urbana-Champaign UrbanaIL61801 United States National Center for Supercomputing Applications University of Illinois at Urbana-Champaign UrbanaIL61801 United States Department of Astronomy School of Physics Peking University Beijing100871 China CAS Key Laboratory for Research in Galaxies and Cosmology Department of Astronomy University of Science and Technology of China Anhui Hefei230026 China School of Astronomy and Space Science University of Science and Technology of China Hefei230026 China National Astronomical Observatory of Japan 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Osawa 2-21-1 Mitaka Tokyo181-8588 Japan Laboratory for Multiwave

"Little Red Dots" (LRDs) are an abundant high-redshift population newly discovered by the James Webb Space Telescope (JWST). They are characterized by a red color in the rest-frame optical band, compact morphology, and broad Balmer emission lines (FWHM >∼ 1000 km s−1) that suggest an AGN nature. Using a method of pixel-by-pixel color selection and relaxing the compactness criteria, we identify three of the first dual LRD candidates in the COSMOS-Web survey with projected separations of 0.′′2-0.′′4 (1-2 pkpc at their photometric redshifts). A comparison between existing LRD samples and mock data reveals that the projected separations of these dual LRD candidates are unlikely to result from chance projections of objects at different redshifts. In one case (CW-B5-15958), the dual LRD includes two bright sources (mF444W = 24.3 and 24.8) with characteristic V-shape spectral energy distribution (SEDs) and photometric redshifts consistent with each other. We find that CW-B5-15958 has a faint off-centered component and a companion galaxy. In the other two dual systems, the brighter LRD exhibits a V-shape SED, while the fainter LRD (mF444W>∼ 26) is undetected in both F115W and F150W. These discoveries suggest that the angular auto-correlation function (ACF) of LRDs exhibits a significant excess (∼ 3 × 102 times) on sub-arcsec (kilo-parsec) separations compared to the extrapolation of a power-law ACF of JWST-found AGNs measured over 10′′-100′′. Follow-up spectroscopic confirmation of their redshifts and the construction of a larger sample are essential to advance our understanding of the evolution of supermassive black holes and the importance of mergers in the early universe. © 2024, CC BY.

关键词： Pixels

来源：评论

学校读者我要写书评

暂无评论

Intelligent identification of two-dimensional nanostructures by machine-learning optical microscopy

引用

Nano research 2018年第12期11卷 6316-6324页

作者： Xiaoyang Lin Zhizhong Si Wenzhi Fu Jianlei Yang Side Guo Yuan Cao Jin Zhang Xinhe Wang Peng Liu Kaili Jiang Weisheng Zhao Fert Beijing Research Institute School ofMicroelectronics & Beijing Advanced Innovation Center for Big Data and Brain Computing (BDBC)Beihang UniversityBeijing 100191China Beihang-GoertekJoint Microelectronics Institute Qingdao Research InstituteBeihang UniversityQingdao 266000China Fert Beijing Research Institute School of Computer Science and Engineering & Beijing Advanced Innovation Center for Big Data and Brain Computing (BDBC)Beihang UniversityBeijing 100191China State Key Laboratory of Low-Dimensional Quantum Physics Department of Physics & Tsinghua-Foxconn Nanotechnology Research CenterCollaborative Innovation Center of Quantum MatterTsinghua UniversityBeijing 100084China

Two-dimensional (2D) materials and their heterostructures, with wafer-scale synthesis methods and fascinating properties, have attracted significant interest and triggered revolutions in corresponding device applications. However, facile methods to realize accurate, intelligent, and large-area characterizations of these 2D nanostructures are still highly desired. Herein, we report the successful application of machine-learning strategy in the optical identification of 2D nanostructures. The machine-learning optical identification (MOI) method endows optical microscopy with intelligent insight into the characteristic color information of 2D nanostructures in the optical photograph. The experimental results indicate that the MOI method enables accurate, intelligent, and large-area characterizations of graphene, molybdenum disulfide, and their heterostructures, including identifications of the thickness, existence of impurities, and even stacking order. With the convergence of artificial intelligence and nanoscience, this intelligent identification method can certainly promote fundamental research and wafer-scale device applications of 2D nanostructures.

关键词： machine-learning optical identification two-dimensional (2D) material heterostructure artificial intelligence

来源：评论

学校读者我要写书评

暂无评论

Generalised geometric brownian motion: Theory and applications to option pricing

arXiv

引用

arXiv 2020年

作者： Stojkoski, Viktor Sandev, Trifce Basnarkov, Lasko Kocarev, Ljupco Metzler, Ralf Faculty of Economics Ss. Cyril and Methodius University Skopje1000 Macedonia Research Center for Computer Science and Information Technologies Macedonian Academy of Sciences and Arts Bul. Krste Misirkov 2 Skopje1000 Macedonia Institute of Physics & Astronomy University of Potsdam Potsdam-GolmD-14776 Germany Institute of Physics Faculty of Natural Sciences and Mathematics Ss. Cyril and Methodius University Arhimedova 3 Skopje1000 Macedonia Faculty of Computer Science and Engineering Ss. Cyril and Methodius University P.O. Box 393 Skopje1000 Macedonia

Classical option pricing schemes assume that the value of a financial asset follows a geometric Brownian motion (GBM). However, a growing body of studies suggest that a simple GBM trajectory is not an adequate representation for asset dynamics due to irregularities found when comparing its properties with empirical distributions. As a solution, we develop a generalisation of GBM where the introduction of a memory kernel critically determines the behavior of the stochastic process. We find the general expressions for the moments, log-moments, and the expectation of the periodic log returns, and obtain the corresponding probability density functions by using the subordination approach. Particularly, we consider subdiffusive GBM (sGBM), tempered sGBM, a mix of GBM and sGBM, and a mix of sGBMs. We utilise the resulting generalised GBM (gGBM) to examine the empirical performance of a selected group of kernels in the pricing of European call options. Our results indicate that the performance of a kernel ultimately depends on the maturity of the option and its moneyness. Copyright © 2020, The Authors. All rights reserved.

关键词： Financial markets

来源：评论

学校读者我要写书评

暂无评论

Stochastic resetting on comb-like structures

arXiv

引用

arXiv 2020年

作者： Domazetoski, Viktor Masó-Puigdellosas, Axel Sandev, Trifce Méndez, Vicenç Iomin, Alexander Kocarev, Ljupco Research Center for Computer Science and Information Technologies Macedonian Academy of Sciences and Arts Bul. Krste Misirkov 2 Skopje1000 Macedonia E-08193 Spain Institute of Physics & Astronomy University of Potsdam Potsdam-GolmD-14776 Germany Institute of Physics Faculty of Natural Sciences and Mathematics Ss. Cyril and Methodius University Arhimedova 3 Skopje1000 Macedonia Department of Physics Technion Haifa32000 Israel Faculty of Computer Science and Engineering Ss. Cyril and Methodius University P.O. Box 393 Skopje1000 Macedonia

We study a diffusion process on a three-dimensional comb under stochastic resetting. We consider three different types of resetting: global resetting from any point in the comb to the initial position, resetting from a finger to the corresponding backbone and resetting from secondary fingers to the main fingers. The transient dynamics along the backbone in all three cases is different due to the different resetting mechanisms, finding a wide range of dynamics for the mean squared displacement. For the particular geometry studied herein, we compute the stationary solution and the mean square displacement and find that the global resetting breaks the transport in the three directions. Regarding the resetting to the backbone, the transport is broken in two directions but it is enhanced in the main axis. Finally, the resetting to the fingers enhances the transport in the backbone and the main fingers but reaches a steady value for the mean squared displacement in the secondary fingers. Copyright © 2020, The Authors. All rights reserved.

关键词： Stochastic systems

来源：评论

学校读者我要写书评

暂无评论

Microstructural Characterization of Cold-Drawn Cu-Ni-Si Alloy Having High Strength and High Conductivity

SSRN

引用

SSRN 2019年

作者： Kim, Hwangsun Ahn, Jee Hyuk Han, Seung Zeon Jo, Janghyun Baik, Hionsuck Kim, Miyoung Han, Heung Nam Department of Materials Science and Engineering Research Institute of Advanced Materials Seoul National University Seoul08826 Korea Republic of Structural Materials Division Korea Institute of Materials Science Changwon51508 Korea Republic of Seoul Center Korea Basic Science Institute Seoul136-713 Korea Republic of

A Cu alloy with high strength and high conductivity, characteristics that are generally traded off, was developed applying discontinuous precipitates as a hardening agent. We observed nanotwins by electron microscopy, which are rarely observed in cold-drawn Cu-Ni-Si alloy. Because nanotwins have little effect on electrical resistivity while effectively interfering with dislocation movement, they are one of the key factors that allow the trade-off characteristics of high strength and high conductivity to manifest simultaneously. Furthermore, we found the development of considerable internal strain and geometrically necessary dislocation due to discontinuous precipitation during aging without deformation. © 2019, The Authors. All rights reserved.

关键词： High resolution transmission electron microscopy

来源：评论

学校读者我要写书评

暂无评论

Estimation of Transition Metal Nitride Surface Plasmon Refractometer Sensitivity

Estimation of Transition Metal Nitride Surface Plasmon Refra...

引用

IEEE Sensors

作者： Frederic Surre Olivier D. Bernal Han-Cheng Seat James H Sharp School of Mathematics Computer Science and Engineering City University of London London UK LAAS-CNRS Universite de Toulouse INP CNRS Toulouse France Systems Power and Energy Research Division School of Engineering University of Glasgow Glasgow UK

We numerically investigate the sensitivity of surface plasmon sensors using transition metal nitrides instead of noble metals, such as silver and gold. These alternative metals present improved thermal and mechanical properties that support the design of better sensors for harsh environment. The results show that titanium nitride and zirconium nitride are viable alternatives to silver as the sensitivity of sensors using these metals is better than sensors using silver.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Direct Polymer Curing: Tailored Graphene Micropatterns by Wafer-Scale Direct Transfer for Flexible Chemical Sensor Platform (Adv. Mater. 2/2021)

引用

advanced Materials 2021年第2期33卷

作者： Yeonhoo Kim Taehoon Kim Jinwoo Lee Yong Seok Choi Joonhee Moon Seo Yun Park Tae Hyung Lee Hoon Kee Park Sol A Lee Min Sang Kwon Hyung-Gi Byun Jong-Heun Lee Myoung-Gyu Lee Byung Hee Hong Ho Won Jang Department of Materials Science and Engineering Research Institute of Advanced Materials Seoul National University Seoul 08826 Republic of Korea Center for Integrated Nanotechnologies Los Alamos National Laboratory Los Alamos NM 87544 USA Materials Deformation Department Korea Institute of Materials Science Changwon 51508 Republic of Korea Graphene Research Center and Graphene Square Inc. Advanced Institute of Convergence Technology Seoul National University Suwon 16229 Republic of Korea Research Center for Materials Analysis Korea Basic Science Institute Gwahak-ro Yuseong-gu Daejeon 34133 Republic of Korea Division of Electronics Information and Communication Engineering Kangwon National University Samcheok 25913 Republic of Korea Department of Materials Science and Engineering Korea University Seoul 02841 Republic of Korea Department of Chemistry Seoul National University Seoul 08826 Republic of Korea

来源：评论

学校读者我要写书评

暂无评论

Reports of the 2018 AAAI fall symposium

Reports of the 2018 AAAI fall symposium

引用

作者： Adler, Aaron Dasgupta, Prithviraj DePalma, Nick Eslami, Mohammed Freedman, Richard G. Laird, John E. Lebiere, Christian Lohan, Katrin Mead, Ross Roberts, Mark Rosenbloom, Paul S. Senft, Emmanuel Stein, Frank Williams, Tom Wray, Kyle Hollins Yaman, Fusun Zilberstein, Shlomo BBN Technologies ColumbiaMD United States Computer Science Department University of Nebraska Omaha United States Samsung Research of America United States Netrias ArlingtonVA United States University of Massachusetts Amherst United States Division of Computer Science and Engineering University of Michigan United States Psychology Department Carnegie Mellon University United States Heriot-Watt University United Kingdom Semio AI United States US Naval Research Laboratory United States Department of Computer Science Institute for Creative Technologies University of Southern California United States University of Plymouth United Kingdom A3 Center IBM United States Colorado School of Mines United States College of Information and Computer Sciences University of Massachusetts Amherst United States BBN Technologies CambridgeMA United States College of Information and Computer Sciences University of Massachusetts Amherst United States

The AAAI 2018 Fall Symposium Series was held Thursday through Saturday, October 18–20, at the Westin Arlington Gateway in Arlington, Virginia, adjacent to Washington, D.C. The titles of the eight symposia were Adversary-Aware Learning Techniques and Trends in Cybersecurity;Artificial Intelligence for Synthetic Biology;Artificial Intelligence in Government and Public Sector;A Common Model of Cognition;Gathering for Artificial Intelligence and Natural System;Integrating Planning, Diagnosis, and Causal Reasoning;Interactive Learning in Artificial Intelligence for Human-Robot Interaction;and Reasoning and Learning in Real-World Systems for Long-Term Autonomy. The highlights of each symposium (except the Gathering for Artificial Intelligence and Natural System symposium, whose organizers failed to submit a report) are presented in this report. Copyright © 2019, Association for the Advancement of Artificial Intelligence. All rights reserved.

关键词： Human robot interaction

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：