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Study on the factors influencing the luminescent properties of YAG:Ce phosphor-doped P2O5-ZnO-B2O3 glass-ceramics

Gongneng Cailiao/Journal of Functional materials 2014年第12期45卷 12051-12054+12059页

作者： Li, Hong Chen, Si Xu, Xu-Jia Hua, Ning Chen, Ming-Xiang State Key Laboratory of Silicate Materials for Architectures Wuhan University of Technology Wuhan 430070 China China Building Material Academy Beijing 100024 China College of Mechanical Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China

Luminescent glass was widely used in some high-tech fields such as white LED lighting, which can greatly improve the optical efficiency of LED devices. In this work, some factors influencing the luminescent properties of P2O5-ZnO-B2O3(PZB) glass-ceramics doped with YAG:Ce phosphor were studied and analysed. Using infrared spectra and orthogonal experimental method, the effects of shaping method, YAG:Ce phosphor content and sintering atmosphere on the luminescent properties of PZB glass-ceramic were studied. The results shown that, shaping method and phosphor content had great effects on the luminescent properties. When the phosphor content reached up to 20wt%, PZB glass-ceramic has the highest luminous intensity, but when the content continued to rise, the emission intensity decreased. Sintering atmosphere did not make any sense to the luminescent properties. Contrary to sintering atmosphere, shaping method played an important role in the luminescent properties. The luminescent properties of matrix glass made by water-quenched method was better than that by pouring method. From the Orthogonal test, it can be seen that the emission intensity of the glass-ceramics ranged from 1 081-4 577 a.u. From high to low, some factors that influenced the emission intensity were YAG:Ce phosphors content, shaping method, sintering temperature and the sintering atmosphere.

关键词： Phosphors

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Study of silicone rubber based diatomite composite materials compression property

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Gongneng Cailiao/Journal of Functional materials 2014年第8期45卷 08024-08027页

作者： Shang, Tao Liu, Yi-Bo Liu, Yu Zhao, Tie-Wei Liu, Xian-Li Wang, Xin College of Mechanical Science and Engineering Jilin University Changchun 130022 China Changchun Tiancheng High-tech Nano Composite Material Co. Ltd. Changchun 130041 China College of Biological and Agricultural Engineering Jilin University Changchun 130022 China

The surface of diatomite particles was modified using titanate coupling agent and the activation mechanism was discussed, the composite materials were fabricated with methyl vinyl silicone rubber and diatomite. The diatomite surface and fracture of composite materials were charactered by SEM. The compression properties of simple silicone rubber and composite materials were researched. The results showed that the average activation grade of diatomite particles modified was 98%, the maximum compression deformation springback of composite materials was obtained while the content of diatomite was up to 30%.

关键词： Rubber

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Motion compensation in a tomographic ultrasound imaging system: toward volumetric scans of a limb for prosthetic socket design

Motion compensation in a tomographic ultrasound imaging syst...

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Annual International Conference of the IEEE engineering in Medicine and Biology Society

作者： Bryan J. Ranger Micha Feigin Nikita Pestrov Xiang Zhang Victor Lempitsky Hugh M. Herr Brian W. Anthony the Harvard-MIT Health Sciences and Technology Program Massachusetts Institute of Technology and Harvard Medical School Cambridge MA 02139 USA the Department of Media Arts and Sciences Massachusetts Institute of Technology Cambridge MA 02139 USA the Skolkovo Institute of Science and Techonology Skolkovo 143025 Russian Federation the Department of Mechanical Engineering Massachusetts Institute of Technology Cambridge MA 02139 USA the Department of Media Arts and Sciences and Harvard-MIT Health Sciences and Technology Program Massachusetts Institute of Technology and Harvard Medical School Cambridge MA 02139 USA

ISBN: (纸本)9781424492695

Current methods of prosthetic socket fabrication remain subjective and ineffective at creating an interface to the human body that is both comfortable and functional. Though there has been recent success using methods like magnetic resonance imaging and biomechanical modeling, a low-cost, streamlined, and repeatable process has not been fully demonstrated. Medical ultrasonography, which has significant potential to expand its clinical applications, is being pursued to acquire data that may quantify and improve the design process and fabrication of prosthetic sockets. This paper presents a new multi-modal imaging approach for acquiring volumetric images of a human limb, specifically focusing on how motion of the limb is compensated for using optical imagery.

关键词： human body that limb is compensated using optical imagery

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Toward an integrated computational system for describing the additive manufacturing process for metallic materials

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Additive Manufacturing 2014年 1卷 52-63页

作者： Martukanitz, Richard Michaleris, Pan Palmer, Todd DebRoy, Tarasankar Liu, Zi-Kui Otis, Richard Heo, Tae Wook Chen, Long-Qing Center for Innovative Materials Processing through Direct Digital Deposition Pennsylvania State University State College PA16801 United States Applied Research Laboratory Pennsylvania State University State College PA16801 United States Mechanical and Nuclear Engineering Department Pennsylvania State University State College PA16801 United States Pan Computing LLC State College PA16801 United States Material Science and Engineering Department Pennsylvania State University State College PA16801 United States

The ability to simulate the thermal, mechanical, and material response in additive manufacturing offers tremendous utility for gaining a deeper understanding of the process, while also having significant practical application. The approach and progress in establishing an integrated computational system for simulating additive manufacturing of metallic components are discussed, with the primary focus directed at the computational intensive components, which include the process and material models. The ability to experimentally measure key characteristics for verification of the models is also presented and is seen as critical in the development of the integrated computational system. Two examples are also presented that utilize the current features of the analyses techniques for exploring and applying additive manufacturing technology. © 2014 Elsevier B.V.

关键词： 3D printers

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Reconfigurable Nanostructures-New Designs for Medicine

Reconfigurable Nanostructures-New Designs for Medicine

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中国微米纳米技术学会纳米科学技术分会第三届年会暨2014全国纳米生物与医学学术会议

作者： Haiqing Dong Yongyong Li Dong Qian Donglu Shi Shanghai East Hospital Institute for biomedical engineering & Nano science School of MedicineTongji UniversityShanghai 200092 Dept. of Mechanical Engineering the University of Texas at DallasRichardsonTX 75080 The Materials Science and Engineering Program Department of Mechanical and Materials EngineeringCollege of Engineering and Applied ScienceUniversity of CincinnatiCincinnatiOH 45221USA

A key challenge in nanomaterials development is the control and manipulation of the structure at the *** are able to meet this challenge through reconfigurable arrays configured on graphene nano-sheets(GNS).Our approach is a new paradigm in materials *** synthesis relies on identification of thermodynamically stable phases and synthesis via chemical *** conventional approach targets a specific functionality,which is fixed once synthesis is *** seek to circumvent the restrictions of conventional synthesis through reconfigurable nanostructural assembly.

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Development of homogeneity in an Al-6061 alloy processed by ECAP and ECAP-conform

Development of homogeneity in an Al-6061 alloy processed by ...

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8th International Conference on Processing and Manufacturing of Advanced materials, THERMEC 2013

作者： Xu, Cheng Langdon, Terence G. Division of Fuel Cell and Energy Technology Ningbo Institute of Material Technology and Engineering Chinese Academy of Sciences Ningbo Zhejiang 315201 China Departments of Aerospace and Mechanical Engineering and Materials Science University of Southern California Los Angeles CA 90089-1453 United States Materials Research Group University of Southampton Southampton SO17 1BJ United Kingdom

ISBN: (纸本)9783038350736

Equal-channel angular pressing (ECAP) has been established as an effective method to achieve ultrafine-grained materials and ECAP combined with the Conform process (ECAP-Conform) is considered a promising candidate to realize continuous processing by ECAP. This paper describes experiments conducted on samples of an Al-6061 alloy in order to evaluate the homogeneity development of the alloy processed by ECAP and ECAP-Conform. The samples of the Al-6061 alloy were processed by ECAP and ECAP-Conform at room temperature up to 4 passes via route BC. The microhardness measurements were recorded both in the cross-sectional planes and along the longitudinal directions of the samples. The results show the alloy obtained significant strengthening using both processes. There was reasonable plastic isotropy after 4 passes of ECAP-Conform in both the cross-sectional plane and the longitudinal direction and the alloy showed a homogeneous microhardness distribution in the cross-sectional plane after 4 passes of conventional ECAP. © (2014) Trans Tech Publications, Switzerland.

关键词： Aluminum alloys

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Semi-solid A356 alloy slurry for rheocasting prepared by a new process

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China Foundry 2013年第3期10卷 176-180页

作者： Liu Zheng Liu Xiaomei Mao Weimin Faculty of Mechanical and Electronic Engineering Jiangxi University of Science and Technology School of Material Science and Engineering University of Science and Technology Beijing

To obtain the semi-solid slurry with uniform and fine structure morphology that satisfies the requirement of rheocasting process, a new process for preparing semi-solid AI alloy slurry was developed, in which local chilling was combined with low superheat pouring and slight electromagnetic stirring （LSPSEMS）. The morphology and the size of primary a-AI in the A356 alloy slurry prepared with the new process, i.e., LSPSEMS with local chilling, were investigated using MIAPS image analyzing software, and the grain refinement mechanism was discussed. The results indicate that the semi-solid primary phase consists of particle-like or globular-like a-AI, and the morphology and grain size of primary a-AI in the slurry can be markedly improved by the new process. The fine primary a-AI distributes uniformly in the slurry, which satisfies the requirement of rheocasting. Compared with the alloy prepared by LSPSEMS, the average equal-area-circle grain diameter of primary a-AI in semi-solid A356 alloy ingot prepared by the new process is decreased from 85.6μm to 68.8 μm at the central area, 112.6 μm to 77.6 μm at the transition area and is 84.7 μm in the edge area, respectively. The corresponding shape factor of primary a-AI is increased from 0.78 to 0.83, 0.54 to 0.77 and 0.28 to 0.59, respectively. In addition, the pouring temperature could be suitably raised from 620-630℃ of the traditional process to 650℃ using this technique, which is convenient for practical operation. The mechanism of grain refinement, in the new process, is that the local chilling quickens up the temperature decrease in the center of the melt. The nuclei could not grow up in a short time so the finer grains are formed in the melt.

关键词： semi-solid A356 alloy new process rheocasting

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Evolution of nonlinear acoustics during creep in welded joint for high Cr ferritic heat resisting steels

Evolution of nonlinear acoustics during creep in welded join...

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IEEE International Ultrasonics Symposium

作者： Toshihiro Ohtani Yuuki Kusagagi Yutaka Ishii Masaaki Tabuchi Hiromichi Hongo Masahiko Hirao Mechanical Engineering Shonan Institute of Technology Fujisawa Japan Graduate Student of Mechanical Engineering Shonan Institute of Technology Fujisawa Japan Creep Resistant Materials Group Materials Reliability Unit National Institute for Material Science Tsukuba Japan Graduate School of Engineering science Osaka University Toyonaka Japan

We investigated the relationship between microstructural change and the evolutions of two nonlinear acoustic characterizations with electromagnetic acoustic resonance (EMAR) throughout the creep life in the welded joints of ASME Grade 122, one of high Cr ferritic heat resisting steels. One was resonant frequency shift and other three-wave mixing. EMAR was a combination of the resonant acoustic technique with a non-contact electromagnetic acoustic transducer (EMAT). We used bulk- shear-wave EMAT, which transmits and receives shear wave propagating in thickness direction of a plate specimen. Creep tests of thick welded joints specimens were interrupted at several time steps at 873 K, and 100 MPa. Two nonlinear acoustic parameters and ultrasonic attenuation decreased from the start to 50% of creep life. After slightly increased, they rapidly increased from 80% of creep life to rupture. We interpreted these phenomena in terms of dislocation recovery, recrystallization, and restructuring related to the initiation and growth of creep void, with support from the SEM and TEM observation.

关键词： Creep Welding Steel Joints Resonant frequency Nonlinear acoustics

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Effects of size polydispersity on electron mobility in a two-dimensional quantum-dot superlattice

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Physical Review B 2014年第14期90卷 144202-144202页

作者： Shicheng Xu Dickson Thian Shengkai Wang Yanming Wang Fritz B. Prinz Department of Mechanical Engineering Stanford University Stanford California 94305 USA Department of Applied Physics Stanford University Stanford California 94305 USA Department of Material Science and Engineering Stanford University Stanford California 94305 USA

We found that the transitions between delocalized electronic states in quantum-dot superlattices with smaller size dispersion can account for higher electron mobility. In particular, we solved for the quantum states of a two-dimensional quantum-dot (QD) superlattice using a one-electron approximation. Electron transport properties were studied by considering hopping transitions among coupled delocalized electronic states. Molecular dynamics simulations were employed to introduce disorders in superlattice configurations as a function of QD size and size dispersion for calculation of electron mobility. The interparticle spacing, size, and temperature dependence of the electron mobility can be well explained within the framework of our analysis.

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Electrochemical behavior of equal channel angular pressed titanium for biomedical application

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AIP Conference Proceedings 2015年第1期1653卷

作者： C. Gode Sh. Attarilar B. Eghbali M. Ebrahimi 1School of Denizli Vocational Technology Program of Machine Pamukkale University Denizli Turkey 2Department of Materials Science and Engineering Sahand University of Technology Tabriz Iran 3Department of Mechanical Engineering Iran University of Science and Technology Tehran Iran

Equal channel angular pressing method is one of the prominent severe plastic deformation techniques to obtain ultrafine grained and even nanostructured metals and alloys by imposing intense plastic strain. As known, pure titanium can be a suitable candidate for biomedical applications because it does not release any toxic ions into the body fluids and also, its biocompatibility properties. The present investigation deals the corrosion behavior of commercial pure titanium before and after ECAP process up to 10 passes by route BC at the 250°C in the 0.9% NaCl solution. The electrochemical results revealed that the corrosion resistance of titanium sample is improved by adding pass number because of the fabrication of passive oxide layer on the surface of the material. It is found that about 92% reduction at the corrosion rate magnitude and also, approximately 41% improvement at the hardness value have been achieved at the final pass as compared to the annealed condition. Furthermore, it is observed that the passive film on the surface of final pass sample is dense and integral with uniform structure, while the as-received one has some rarefactions and does not have very uniform surface.

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