检索结果-内蒙古大学图书馆

Coupling of spin and orbital excitations in the iron-based superconductor FeSe0.5Te0.5

Physical Review B 2010年第22期81卷 220502(R)-220502(R)页

作者： S.-H. Lee Guangyong Xu W. Ku J. S. Wen C. C. Lee N. Katayama Z. J. Xu S. Ji Z. W. Lin G. D. Gu H.-B. Yang P. D. Johnson Z.-H. Pan T. Valla M. Fujita T. J. Sato S. Chang K. Yamada J. M. Tranquada Department of Physics University of Virginia Charlottesville Virginia 22904-4714 USA Condensed Matter Physics & Materials Science Department Brookhaven National Laboratory Upton New York 11973-5000 USA Department of Materials Science & Engineering Stony Brook University Stony Brook New York 11794 USA Physics Department The City College of New York New York New York 10031 USA Institute for Materials Research Tohoku University Senda Miyagi 980-8577 Japan Neutron Science Laboratory Institute for Solid State Physics University of Tokyo 106-1 Shirakata Tokai Ibaraki 319-1106 Japan NIST Center for Neutron Research National Institute of Standards and Technology Gaithersburg Maryland 20899 USA WPI Research Center Advanced Institute for Materials Research Tohoku University Sendai 980-8577 Japan

We present a combined analysis of neutron scattering and photoemission measurements on superconducting FeSe0.5Te0.5. The low-energy magnetic excitations disperse only in the direction transverse to the characteristic wave vector (12,0,0) whereas the electronic Fermi surface near (12,0,0) appears to consist of four incommensurate pockets. While the spin resonance occurs at an incommensurate wave vector compatible with nesting, neither spin-wave nor Fermi-surface-nesting models can describe the magnetic dispersion. We propose that a coupling of spin and orbital correlations is key to explaining this behavior. If correct, it follows that these nematic fluctuations are involved in the resonance and could be relevant to the pairing mechanism.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Epipolar geometry of catadioptric stereo systems with planar mirrors

引用

Image and Vision Computing 2009年第8期27卷 1047-1061页

作者： Wu, Hsien-Huang P. Lee, Meng-Tu Weng, Ping-Kuo Chen, Soon-Lin Graduate School of Engineering Science and Technology National Yunlin University of Science and Technology #123 University Road Section 3 Yunlin Douliou 640 Taiwan Department of Computer Science and Information Engineering Nan Kai Institute of Technology Taiwan Chung-Shan Institute of Science and Technology Materials RD Center Solid-State Devices Materials Section P.O. Box 90008-8-7 Lung-Tan Tao-Yuan 325 Taiwan

In order to simplify the design and implementation of a stereo vision system, catadioptric instruments have been used to capture stereo images with a single camera. These catadioptric stereo systems not only provide radiometric advantages over traditional two-camera stereo, but also reduce the complexity and cost of acquiring stereoscopic video. Although much research has been done on the design of the catadioptric stereo system, little attention has been paid to analyze the planar catadioptric stereo (PCS) system based on the epipolar geometry. In this paper, we investigated characteristics of a selected PCS system and proved that it can be approximated by affine epipolar geometry. This affine model reduces the number of parameters in the fundamental matrix from seven in the conventional stereo system to only four in the PCS system. Experimental results verify that estimation of the fundamental matrix for a PCS system can be more robust, precise, and much easier to implement with the affine model. Furthermore, rectification of the image pair based on the affine fundamental matrix can achieve better performance with much less geometric distortion. These significant advantages confirm the usefulness of an affine fundamental matrix model for the selected PCS system. © 2008 Elsevier B.V. All rights reserved.

关键词： Cameras

来源：评论

学校读者我要写书评

暂无评论

A Room‐Temperature Reactive‐Template Route to Mesoporous ZnGa2O4with Improved Photocatalytic Activity in Reduction of CO2†

引用

Angewandte Chemie 2010年第36期122卷

作者： Shi Cheng Yan Shu Xin Ouyang Jun Gao Ming Yang Jian Yong Feng Xiao Xing Fan Li Juan Wan Zhao Sheng Li Jin Hua Ye Yong Zhou Zhi Gang Zou Ecomaterials and Renewable Energy Research Center National Laboratory of Solid State Microstructures Nanjing University 22 Hankou Road Nanjing 210093 (China) Photocatalytic Materials Center (PCMC) National Institute for Materials Science (NIMS) Sengen Tsukuba Ibaraki 305‐0047 (Japan) Department of Materials Science and Engineering Nanjing University 22 Hankou Road Nanjing 210093 (China)

来源：评论

学校读者我要写书评

暂无评论

Deterministic modeling of the corrosion of low-carbon steel by dissolved carbon dioxide and the effect of acetic acid. I-effect of carbon dioxide

Deterministic modeling of the corrosion of low-carbon steel ...

引用

作者： Rosas-Camacho, O. Urquidi-Macdonald, M. Macdonald, D.D. Intercollegiate Graduate Program in Materials Science and Engineering Penn State University University Park PA 16802 United States Department of Engineering Science and Mechanics Penn State University University Park PA 16802 United States Center for Electrochemical Science and Technology Department of Materials Science and Engineering Penn State University University Park PA 16802 United States

ISBN: (纸本)9781607681212

Carbon dioxide (CO2) corrosion of carbon steel in the presence of brine has been a recognized problem in oil production for many years and it is becoming more common with the extensive use of CO2-flooding as an oil recovery technique. The presence of acetic acid is systematic in oil fields, however, its role in corrosion has not been well-recognized and its exact mechanistic role is still debated. The present work was carried out, in the first instance, to focus on developing an understanding of CO 2-corrosion of low-carbon steel and, in the second instance to ascertain the corrosion mechanistic effect of acetic acid. This understanding is achieved by developing a deterministic model that explains and accounts for the experimental observations from Electrochemical Impedance Spectroscopy (EIS) data and by extracting values for physical und chemical parameters that describe the system. The impedance model, based on the Point Defect Model, provides a good account of the formation and growth of a bi-layer passive film that comprises an point-defective oxide (inner) layer adjacent to the metal surface and a precipitated (outer) layer of siderite, FeCO3, that forms on the top of the inner layer. We conclude that the barrier oxide layer exists on the steel surface at pH values ranging from 4 to 6. ©The Electrochemical Society.

关键词： Carbon dioxide

来源：评论

学校读者我要写书评

暂无评论

Economical dental stereoradiography in digital era

Economical dental stereoradiography in digital era

引用

5th International Conference on Information Assurance and Security, IAS 2009

作者： Wu, Hsien-Huang P. Chang, Shih-Hsin Weng, Ping-Kuo Chen, Soon-Lin Graduate School of Engineering Science and Technology National Yunlin University of Science and Technology 123 University Rd. Yunlin Douliou 640 Taiwan Chung-Shan Institute of Science and Technology Materials RD Center Solid-State Devices Materials Section P.O. Box 90008-8-7 Lung-Tan Tao-Yuan 325 Taiwan

ISBN: (纸本)9780769537443

Because of the prevalence of digital imaging in radiology and the developments of electronic three-dimensional (3D) viewing devices, digital stereoradiography will become an efficient and economical way for improving the diagnostic efficacy. A viewing device based on one compact mirror and two flat-panel LCDs to achieve high resolution of digital dental stereoradiography is proposed and its effectiveness was evaluated. The proposed viewing method shows better performance compared with the other two approaches. Clinical use of the viewing instruments can be expected to show similar results. © 2009 IEEE.

关键词： Depth perception

来源：评论

学校读者我要写书评

暂无评论

Nanoindentation-induced pile-up in hydrogenated amorphous silicon

引用

Journal of Physics: Conference Series 2010年第1期253卷

作者： B Pantchev P Danesh J Wiezorek B Schmidt Institute of Solid State Physics Bulgarian Academy of Sciences Tzarigradsko Chaussee 72 1784 Sofia Bulgaria Department of Mechanical Engineering and Materials Science Swanson School of Engineering University of Pittsburgh 848 Benedum Hall Pittsburgh PA 15261 USA Research Center Dresden-Rossendorf Inc. Institute of Ion Beam Physics and Materials Research D-01314 Dresden Germany

Nanoindentation-induced material extrusion around the nanoindent (pile-up) leads to an overestimation of elastic modulus, E, and nanohardness, H, when the test results are evaluated using the Oliver and Pharr method. Factors affecting the pile-up during testing are residual stresses in film and ratio of film and substrate mechanical properties. Nanoindentation of hydrogenated amorphous silicon (a-Si:H) films has been carried out with the aim to study the effect of residual compressive stress on the pile-up in this material. To distinguish the contribution of compressive stress to the appearance of pile-up ion implantation has been used as a tool, which reduces the compressive stress in a-Si:H. Scanning probe microscope has been used for the imaging of the indent and evaluation of the pile-up. The values of E and H have been obtained from the experimental load-displacement curves using depth profiling with Berkovich tip, which has created negligible pile-up. A sharper cube corner tip has been used to study the pile-up. It has been established that pile-up is determined by the material plasticity, when the compressive stress is below 200 MPa. The contribution of mechanical stress to the pile-up is essential for the stress as high, as about 500 MPa.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Economical Dental Stereoradiography in Digital Era

Economical Dental Stereoradiography in Digital Era

引用

The Fifth International Conference on Information Assurance and Security(第五届信息保障与安全国际会议)

作者： Shih-Hsin Chang Hsien-Huang P.Wu Ping-Kuo Weng Soon-Lin Chen Graduate School of Engineering Science and Technology National Yunlin University of Science and Tech Chung-Shan Institute of Science and Technology Materials RD Center Solid-State Devices Materials Sec

ISBN: (纸本)9780769537443

Because of the prevalence of digital imaging in radiology and the developments of electronic three-dimensional (3D) viewing devices, digital stereoradiography will become an effcient and economical way for improving the diagnostic effcacy. A viewing device based on one compact mirror and two flat-panel LCDs to achieve high resolution of digital dental stereoradiography is proposed and its effectiveness was evaluated. The proposed viewing method shows better performance compared with the other two approaches. Clinical use of the viewing instruments can be expected to show similar results.

关键词： Stereoscopic viewing digital dental stereoradiography 3D viewing devices depth perception autostereoscopic LCD

来源：评论

学校读者我要写书评

暂无评论

The engineering of Everyday Things: Simple experiments for the thermal and fluid sciences

The Engineering of Everyday Things: Simple experiments for t...

引用

2009 ASEE Annual Conference and Exposition

作者： Recktenwald, Gerald Edwards, Robert Howe, Douglas Faulkner, Jenna Hsieh, Calvin Department of Mechanical Engineering Portland State University United States Department of Mechanical and Materials Engineering Portland State University United States Department of Engineering Pennsylvania State University at Erie Behrend College United States PSU Center for Science Education BSME Program Portland State University United States Hydroelectric Design Center Branch US Army Corps of Engineers Portland OR United States

A series of demonstrations and laboratory exercises have been developed to teach fundamental concepts in the thermal and fluid sciences of the undergraduate engineering curriculum. This material is part of an educational research project called the engineering of Everyday Things. The title reflects the use of common technology like hair dryers, blenders, toasters and bicycle pumps, which are used to demonstrate principles of thermodynamics, fluid mechanics and heat transfer. The project also uses simple laboratory devices such as pipes with sudden expansions and open tanks of water. This paper provides an overview of the EET project and shows how this material can be used as in-class demonstration or as in guided-inquiry laboratory exercises. Representative results of formative assessment for the in-class demonstrations, learning gain, and attitude change for the guided-inquiry exercises are given. © American Society for engineering Education, 2009.

关键词： Demonstrations

来源：评论

学校读者我要写书评

暂无评论

Substrates Influence on the Structure and Static Electromagnetic Properties of FeCoB-SiO2 Thin Films

Substrates Influence on the Structure and Static Electromagn...

引用

2009 International Conference on Applied Superconductivity and Electromagnetic Devices(应用超导与电磁装置技术国际会议 ASEME 2009)

作者： L. Zhang Z. W. Zhu L. J. Deng Engineering Research Center of Electromagnetic Wave Absorbing Materials Ministry of Education School of Microelectronics and Solid-State Electronics University of Electronic Science and Technology of China Chengdu China

The microstructure and electromagnetic properties of FeCoB-SiO2 thin films which were deposited on different substrates (silicon, glass and Mylar) by using magnetron sputtering were studied. X-Ray Diffraction revealed that FeCo nanocrystalline only precipitated in FeCoB-SiO2 thin films on silicon and glass substrates, and the FeCoB-SiO2 films on Mylar substrate were amorphous. The surface images obtained by atomic microscopy (AFM) indicated that films on Mylar substrate with biggest particle size (about 120-150 nm), and agglomerated particle was discovered. The static electromagnetic properties, including resistivity and saturation magnetization for the films on different substrates, had also been investigated. The films sputtered on glass showed highest resistivity (2140 μΩcm) and a biggest saturation magnetization (4 πMs = 13 kG).

关键词： static electromagnetic properties resistivity Mylar substrate amorphous

来源：评论

学校读者我要写书评

暂无评论

Low-temperature ozone passivation for improving the quality of sputtered HfOx thin-film

引用

materials Letters 2009年第22期63卷 1914-1916页

作者： Chen, Shih-Ching Chang, Ting-Chang Su, Hsuan-Hsiang Yang, Po-Chun Lu, Jin Huang, Hui-Chun Gan, Der-Shin Ho, New-Jin Shi, Yi Department of Physics National Sun Yat-Sen University Kaohsiung 804 Taiwan Center for Nanoscience and Nanotechnology National Sun Yat-Sen University Kaohsiung 804 Taiwan Department of Photonics National Sun Yat-Sen University Kaohsiung 804 Taiwan Institute of Materials Science and Engineering National Sun Yat-Sen University Kaohsiung 804 Taiwan Department of Physics National Laboratory of Solid State Microstructures Nanjing University Nanjing 210093 China

In this study, we proposed the low temperature (150 °C) oxygen (O2) and ozone (O3) treatments with a high pressure of 68 atm to improve the quality of sputtered hafnium-oxide (HfOx) thin-film dielectric. XPS results indicate that the binding energy of Hf-O became stronger and traps in dielectric film could be effectively passivated after the O2 and O3 treatments. The accumulation capacitance for the as-deposited HfOx sample can be improved from 261 pF to 303 pF and 366 pF for the O2 and O3 treated samples, respectively. The O3 treated sample also exhibits the negligible hysteresis phenomenon and slight flatband voltage shift. © 2009 Elsevier B.V. All rights reserved.

关键词： Passivation

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：