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Corrigendum to “A size-dependent tensorial plasticity model for FCC single crystal with irradiation” Int. J. Plast. 65 (2015), 152–167

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International Journal of Plasticity 2015年 69卷 170-170页

作者： Xiazi Xiao Dingkun Song Jianming Xue Haijian Chu Huiling Duan State Key Laboratory for Turbulence and Complex System Department of Mechanics and Engineering Science College of Engineering Peking University Beijing 100871 PR China HEDPS Center for Applied Physics and Technology Peking University Beijing 100871 PR China State Key Laboratory of Nuclear Physics and Technology School of Physics Peking University Beijing 100871 PR China Department of Mechanics College of Sciences Shanghai University Shanghai 200444 PR China State Key Laboratory for Mechanical Behavior of Materials Xi'an 710049 PR China

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Effect of Surface Termination on the Electronic Properties of LaNiO3 Films

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Physical Review applied 2014年第5期2卷 054004-054004页

作者： Divine P. Kumah Andrei Malashevich Ankit S. Disa Dario A. Arena Frederick J. Walker Sohrab Ismail-Beigi Charles H. Ahn Center for Research on Interface Structures and Phenomena and Department of Applied Physics Yale University New Haven Connecticut 06520 USA National Synchrotron Light Source Brookhaven National Laboratory Upton New York 11973 USA Department of Mechanical Engineering and Materials Science Yale University New Haven Connecticut 06520 USA

The electronic and structural properties of thin LaNiO3 films grown by using molecular beam epitaxy are studied as a function of the net ionic charge of the surface terminating layer. We demonstrate that electronic transport in nickelate heterostructures can be manipulated through changes in the surface termination due to a strong coupling of the surface electrostatic properties to the structural properties of the Ni—O bonds that govern electronic conduction. We observe experimentally and from first-principles theory an asymmetric response of the structural properties of the films to the sign of the surface charge, which results from a strong interplay between electrostatic and mechanical boundary conditions governing the system. The structural response results in ionic buckling in the near-surface NiO2 planes for films terminated with negatively charged NiO2 and bulklike NiO2 planes for films terminated with positively charged LaO planes. The ability to modify transport properties by the deposition of a single atomic layer can be used as a guiding principle for nanoscale device fabrication.

关键词： Lanthanum compounds

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Issues and progress in the prediction of ocean submesoscale features and internal waves

Issues and progress in the prediction of ocean submesoscale ...

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OCEANS

作者： Timothy F. Duda Weifeng Gordon Zhang Karl R. Helfrich Arthur E. Newhall Ying-Tsong Lin James F. Lynch Pierre F. J. Lermusiaux P. J. Haley John Wilkin Applied Ocean Physics and Engineering Department Woods Hole Oceanographic Institution Woods Hole Massachusetts USA Mechanical Engineering Department and Center for Ocean Engineering Massachusetts Institute of Technology Cambridge Massachusetts USA Institute of Marine and Coastal Sciences Rutgers University New Brunswick New Jersey USA

Data-constrained dynamical ocean modeling for the purpose of detailed forecasting and prediction continues to evolve and improve in quality. Modeling methods and computational capabilities have each improved. The result is that mesoscale phenomena can be modeled with skill, given sufficient data. However, many submesoscale features are less well modeled and remain largely unpredicted from a deterministic event standpoint, and possibly also from a statistical property standpoint. A multi-institution project is underway with goals of uncovering more of the details of a few submesoscale processes, working toward better predictions of their occurrence and their variability. A further component of our project is application of the new ocean models to ocean acoustic modeling and prediction. This paper focuses on one portion of the ongoing work: Efforts to link nonhydrostatic-physics models of continental-shelf nonlinear internal wave evolution to data-driven regional models. Ocean front-related effects are also touched on.

关键词： Computational modeling Predictive models Tides Mathematical model Data models Acoustics

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Properties of high latitude irregularities with a short-baseline 2D GPS scintillation array

Properties of high latitude irregularities with a short-base...

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General Assembly and Scientific Symposium, URSI

作者： Seebany Datta-Barua Yang Su Kshitija Deshpande Gary S. Bust Mechanical Materials and Aerospace Engineering Department Illinois Institute of Technology Chicago IL USA Bradley Department of Electrical and Computer Engineering Virginia Polytechnic Institute and State University Blacksburg VA USA Johns Hopkins University Applied Physics Laboratory Laurel MD USA

Variations in plasma density in the ionospheric layer can cause fluctuations in the received amplitude or phase of a trans-ionospherically propagating radio wave. Such fluctuations are termed scintillation, and can lead to loss of continuity in radio-navigation for users of Global Navigation Satellite Systems (GNSS) such as GPS, Beidou, GLONASS, and Galileo. A scintillating signal can cause a user's receiver to lose lock on one or more satellites at a given instant. These satellites are then temporarily unavailable for position, navigation and timing estimates, reducing accuracy. Scintillation is observed most frequently in the equatorial and auroral zones. In these regions, different physical mechanisms are responsible for the formation of ionospheric irregularities that cause scintillation.

关键词： Arrays Global Positioning System Electronic mail Educational institutions Receivers Fluctuations Satellites

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Influence of service temperature on tribological characteristics of self-lubricant coatings： A review

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Frontiers of Materials Science 2013年第1期7卷 28-39页

作者： Jun-Feng YANG Yan JIANG Jens HARDELL Braham PRAKASH Qian-Feng FANG Key Laboratory of Materials Physics Institute of Solid State Physics Chinese Academy of Sciences Hefei 230031 China Department of Applied Physics and Mechanical Engineering Lulea University of Technology SE-971 87 Lulea Sweden

Self-lubricating coatings have been widely used to reduce friction in moving machine assemblies. However, the tribological performance of these coatings is strongly dependent on the service temperature. In this paper, an extensive review pertaining to the influence of operating service temperature on tribological performance of self-lubricating coatings has been carried out. Based on the effective lubricating temperature range, the self-lubricating coatings developed in the past have been divided into three groups: low temperature lubricant coating (from ?200°C to room temperature), moderate temperature lubricant coating (from room temperature to 500°C) and high temperature lubricant coating (> 500°C). Ideas concerning possible ways to extend the operating temperature range of self-lubricating coatings have been presented as follows: hybridized tribological coating, adaptive tribological coatings, and diffusion rate limited solid lubricant coating. In addition, a new self-lubricating coating formulation for potential application at a wide operating temperature range has been proposed.

关键词： temperature solid lubricant self-lubricating coating tribological property

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Hypocoordinated solids in particulate media

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Physical Review E 2014年第6期89卷 062203-062203页

作者： Thibault Bertrand Carl F. Schreck Corey S. O'Hern Mark D. Shattuck Department of Mechanical Engineering & Materials Science Yale University New Haven Connecticut 06520-8260 USA Center for Research on Interface Structures and Phenomena Yale University New Haven Connecticut 06520 USA Department of Physics Yale University New Haven Connecticut 06520-8120 USA Department of Applied Physics Yale University New Haven Connecticut 06520-8120 USA Benjamin Levich Institute and Physics Department The City College of the City University of New York New York New York 10031 USA

We propose a “phase diagram” for particulate systems with purely repulsive contact forces, such as granular media and colloids. We characterize two classes of behavior as a function of the input kinetic energy per degree of freedom T0 and packing fraction deviation from jamming onset Δϕ=ϕ−ϕJ using simulations of frictionless disks. Isocoordinated solids (ICS) exist above jamming; they possess an average contact number equal to the isostatic value ziso. ICS display “strict” harmonic response, where the density of vibrational modes from the Fourier transform of the velocity autocorrelation function is a set of sharp peaks at eigenfrequencies ωkd of the dynamical matrix. In contrast, hypocoordinated solids (HCS) occur above and below jamming and possess fluctuating networks of interparticle contacts but do not undergo cage-breaking particle rearrangements. The density of vibrational frequencies for the HCS is not a collection of sharp peaks at ωkd, but it does possess a common form over a range of Δϕ and T0.

关键词： Hypocoordinated solids particulate Contact numbers Particulates harmonic response Vibrational frequencies solids jamming Velocity autocorrelation function Human Placental Lactogen kinetic energy Fourier Transform Integrated circuits Vibrations modes

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Connection between the packing efficiency of binary hard spheres and the glass-forming ability of bulk metallic glasses

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Physical Review E 2014年第3期90卷 032311-032311页

作者： Kai Zhang W. Wendell Smith Minglei Wang Yanhui Liu Jan Schroers Mark D. Shattuck Corey S. O'Hern Department of Mechanical Engineering and Materials Science Yale University New Haven Connecticut 06520 USA Center for Research on Interface Structures and Phenomena Yale University New Haven Connecticut 06520 USA Department of Physics Yale University New Haven Connecticut 06520 USA Department of Physics and Benjamin Levich Institute The City College of the City University of New York New York New York 10031 USA Department of Applied Physics Yale University New Haven Connecticut 06520 USA

We perform molecular dynamics simulations to compress binary hard spheres into jammed packings as a function of the compression rate R, size ratio α, and number fraction xS of small particles to determine the connection between the glass-forming ability (GFA) and packing efficiency in bulk metallic glasses (BMGs). We define the GFA by measuring the critical compression rate Rc, below which jammed hard-sphere packings begin to form “random crystal” structures with defects. We find that for systems with α≳0.8 that do not demix, Rc decreases strongly with ΔϕJ, as Rc∼exp(−1/ΔϕJ2), where ΔϕJ is the difference between the average packing fraction of the amorphous packings and random crystal structures at Rc. Systems with α≲0.8 partially demix, which promotes crystallization, but we still find a strong correlation between Rc and ΔϕJ. We show that known metal-metal BMGs occur in the regions of the α and xS parameter space with the lowest values of Rc for binary hard spheres. Our results emphasize that maximizing GFA in binary systems involves two competing effects: minimizing α to increase packing efficiency, while maximizing α to prevent demixing.

关键词： METALLIC glasses BINARY metallic systems CRYSTAL structure SPHERE packings CRYSTALLIZATION COMPRESSION loads

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Plasmofluidics: Plasmofluidics: Merging Light and Fluids at the Micro-/Nanoscale (Small 35/2015)

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Small 2015年第35期11卷

作者： Mingsong Wang Chenglong Zhao Xiaoyu Miao Yanhui Zhao Joseph Rufo Yan Jun Liu Tony Jun Huang Yuebing Zheng Department of Mechanical Engineering Materials Science and Engineering Program Texas Materials Institute The University of Texas at Austin Austin Texas 78712 USA Department of Physics Electro-Optics Graduate Program University of Dayton Dayton Ohio 45469 USA Google Inc. 1600 Amphitheatre Pkwy Mountain View CA 94043 USA Department of Engineering Science and Mechanics Department of Biomedical Engineering Materials Research Institute Huck Institute of Life Sciences The Pennsylvania State University University Park Pennsylvania 16802 USA Institute of Materials Research and Engineering Agency for Science Technology and Research (A*STAR) 3 Research Link Singapore 117602 Singapore

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Dielectric properties of ternary composites of triblock polymer surfactant, liquid crystal and organic solvent

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Journal of Advanced Dielectrics 2014年第3期4卷 33-39页

作者： M.R.Fisch Clinton Braganza L.C.Chien R.G.Petschek College of Applied Engineering Sustainabilityand Technology Kent State UniversityKentOhio 44242USA Liquid Crystal Institute and Chemical Physics Interdisciplinary Program Kent State University KentOhio 44242USA Department of Physics Case Western Reserve University10600 Euclid Ave.ClevelandOhio 44106USA

Dielectric spectroscopy,at room temperature(20℃),is used to study the dielectric response of ternary mixtures of commercial nematic liquid crystal mixtures E7 and E33,an organic solvent N-Methyl-2-Pyrrolidone(NMP)and a triblock polymers in the frequency range from 0.01Hz to *** results indicate a dielectric relaxation in the hectohertz ***,both E7 and NMP have rather large low frequency conductivities;however,the low frequency(0.01–10Hz)behavior of the mixtures has no such *** attribute this behavior to an ion getter effect of the triblock polymer *** ternary mixtures obtain a real dielectric constant near 230,and loss tangent less than 0.05 at frequencies near 10mHz.

关键词： Emulsion dielectric properties liquid crystal

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Characterization of a compressed sensing PET detector and data acquisition system: Effects of multiplexing and sampling rate

Characterization of a compressed sensing PET detector and da...

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IEEE Symposium on Nuclear Science (NSS/MIC)

作者： Chen-Ming Chang Alexander M. Grant Brian J. Lee Craig S. Levin Departments of Applied Physics and Radiology Stanford University Stanford CA USA Departments of Bioengineering and Radiology Stanford University Stanford CA USA Departments of Mechanical Engineering and Radiology Stanford University Stanford CA USA Department of Radiology Electrical Engineering Bioengineering and Physics Stanford University Stanford CA USA

ISBN: (纸本)9781479960989

Reducing the number of readout channels of PET detectors with multiplexing can save the cost and complexity for developing a scanner. However, a high multiplexing ratio can also degrade the signal-to-noise (SNR) ratio of the detector since the noise of the multiplexed channels is summed together. Compressed sensing (CS) was recently shown to be a promising multiplexing method for PET detectors that can achieve high multiplexing ratio while resolving simultaneous hits on multiple pixels with high SNR recovery for PET detectors. In this work, we study the effects of multiplexing and sampling rate on the performance of the CS detectors and the corresponding DAQ system we have developed for a PET insert for simultaneous PET/MR brain imaging. The coincidence time resolution acquired by a pair of single-crystal detectors degraded from 1.4 ns to 3.2 ns when the sampling rate dropped from 20GHz (sampled by the digital oscilloscope) to 65MHz (sampled by the 256-channel DAQ system developed in house). The coincidence time resolution further degraded to 3.7 ns when the coincidence events were acquired by two CS detectors (with a multiplexing ratio of 8:1) and sampled by the DAQ system, indicating the effect of multiplexing on the timing performance. Possible future studies to diagnose and mitigate the causes of timing performance degradation are discussed.

关键词： Detectors Multiplexing Data acquisition Positron emission tomography Oscilloscopes Image resolution Timing

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