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Physics of Fluids : Breakup of the tail of a bubble in a non-Newto...

By: Enrique Soto, Roberto Zenit, and Octavio Manero

Description:

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Physics of Fluids : Direct numerical simulation and Lagrangian mod...

By: Brian L. Sawford and Stephen M. de Bruyn Kops

Description: Direct numerical simulation (DNS) results are presented for the joint statistics of two inhomogeneous scalar fields, one due to a mixing layer source and the other due to a contiguous top-hat source. These two sources form the basis for all scalar mixing across three streams. The results are used to assess the performance of a Lagrangian stochastic modeling system incorporating the interaction with the conditional mean mixing model at two different times: A ...

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Biblioteca Hispanica : Programme an Elementary Course of Natural H...

By: Manuel Cazurro Ruiz
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Biblioteca Hispanica : Speech Read on the Literary University of S...

By: Serafin Sanz and Agud

Description: Botany History

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Journal of Applied Physics : Optical properties of m-plane GaN qua...

By: Julien Renard, Benoit Amstatt, Catherine Bougerol, Edith Bellet-Amalric, Bruno Daudin et al

Description: We have studied the optical properties of m-plane GaN/AlN quantum dots and quantum wires. The photoluminescence, both on an ensemble of nanostructures and on single nanostructures, shows a strong degree of linear polarization perpendicular to the c-axis. Time-resolved photoluminescence evidences the strong reduction in the quantum confined Stark effect. Temperature dependence measurements suggest a difference in nonradiative processes between quantum dots and quantum wires.

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Biblioteca Hispanica : Regulation of the Natural History Museum of...

By: Madrid
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Applied Physics Letters : The enhancement of ZnO nanowalls photoco...

By: F. Fang, D. X. Zhao, B. H. Li, Z. Z. Zhang, J. Y. Zhang et al

Description: 10 nm sized hexagonal CdS nanoparticles were decorated on the surface of well-aligned ZnO nanowall through a facile hydrothermal approach. The effects of CdS-cap layer on the optical and photoelectrical properties of ZnO nanowalls have been studied. It was found the CdS acted not only as a passivation layer to suppress the detrimental surface states of ZnO nanowalls, which reduced the deep-level emissions, but also as an interfacial carrier transport layer t...

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Journal of Applied Physics : Mechanical behavior of stressed films...

By: Conal E. Murray and K. L. Saenger

Description: The effects of stressed thin films on substrates that possess anisotropic elasticity have been measured and modeled. Substrate curvature induced by a uniform, stressed film will be axisymmetric for substrates possessing greater than twofold in-plane symmetry, and anisotropic for twofold symmetric substrates. For a (011) Si substrate, the difference between the curvature along the 〈110〉 and 〈100〉 principal axes varies by approximately 47%. A simple, analytica...

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Journal of Applied Physics : Time dependence of the electronic str...

By: Jun Onoe, Takahiro Ito, and Shin-ichi Kimura

Description: Time dependence of the electronic structure of an electron-beam (EB) irradiated C60 film (20–30 nm thick) has been examined using in situ high-resolution ultraviolet photoelectron spectroscopy. It is found that the electronic states of the C60 film have been changed continuously from an insulator (pristine C60 films) to a semiconductor and finally to a metal as EB-irradiation time increased. This can be explained by the increase in polymerization degree of a...

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The Journal of Chemical Physics : Structure of gold atoms on stoic...

By: Changjun Zhang, Angelos Michaelides, David A. King, and Stephen J. Jenkins

Description: Within the framework of the GGA+U implementation of density functional theory, we investigate atomistic and electronic structures of Au adsorbed on the stoichiometric and the defective CeO2{111} surfaces, in the latter of which either O or Ce vacancies are presented. We show that on the stoichiometric surface, the most stable adsorption site of Au is not on the top of the outermost O atoms, as previously suggested, but on a bridgelike site in which the Au di...

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Applied Physics Letters : Enhanced contrast coherent anti-Stokes R...

By: Michael R. Beversluis and Stephan J. Stranick

Description: We have experimentally demonstrated enhanced image contrast of sample fine structure in a coherent anti-Stokes Raman scattering (CARS) microscope using liquid crystal spatial light modulators as programmable Toraldo-style pupil phase masks. We demonstrated through modeling, implementation, and verification of the focal intensity and phase distributions of the excitation beams the trade-offs between improved image contrast and CARS signal levels.

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Physics of Fluids : Circulation and energy of the leading vortex r...

By: L. Gao, S. C. M. Yu, J. J. Ai, and A. W. K. Law

Description: The gravity-driven starting jet characteristics over the range of Reynolds numbers from 1179 to 10 611 have been investigated using planar laser induced fluorescence and particle image velocimetry. Of the 17 cases investigated, pinch off for the leading vortex was found to appear at Reynolds number above 3000. For those cases involving pinch off, limiting values for the nondimensional circulation for the leading vortex could be identified at around 1.26 and ...

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Journal of Applied Physics : Comparison of resonant-phonon-assiste...

By: H. Li, J. C. Cao, Z. Y. Tan, and S. L. Feng

Description: The authors compare resonant-phonon-assisted terahertz quantum-cascade lasers with different active region designs, i.e., one-well injector and three-well module, using an ensemble Monte Carlo method. Carrier transport under injection anticrossing, parasitic anticrossing, and collection anticrossing couplings are investigated for both structures. The results show that the main parasitic current channel is the resonance of the injector 1′ with the lower lasin...

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Review of Scientific Instruments : Single-sided radio-frequency fi...

By: Laouès Guendouz, Sébastien Leclerc, Alain Retournard, Ahcène Hedjiedj, and Daniel Canet

Description: Magnetic field gradients are nowadays indispensable to most nuclear magnetic resonance experiments and are at the basis of magnetic resonance imaging (MRI). Most of the time, gradients of the static magnetic field are employed. Gradients of the radio-frequency (rf) field may constitute an interesting alternative. Until now, they were produced by a single loop. We demonstrate in this paper how two unsymmetrical series loops can be optimized to produce rf grad...

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Physics of Plasmas : Doppler spectroscopy of hydrogen Balmer lines...

By: N. M. Šišovic and N. Konjevic

Description: The results of Doppler spectroscopy of hydrogen Balmer lines from a stainless steel (SS) and copper (Cu) hollow cathode (HC) glow discharge in ammonia and argon-ammonia mixture are reported. The experimental profiles in ammonia discharge are fitted well by superposing three Gaussian profiles. The half widths, in energy units, of narrow and medium Gaussians are in the ranges 0.3–0.4 eV and 3–4 eV, respectively, for both hollow cathodes what is expected on the...

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Journal of Applied Physics : Single dominant distribution of Ge na...

By: Seishi Abe, Masato Ohnuma, D. H. Ping, and Shigehiro Ohnuma

Description: This paper investigates size distribution of Ge nanogranules embedded in Al oxide thin film prepared by rf reactive sputtering method. It is found from the results of x-ray diffraction and small angle x-ray diffraction spectroscopy that their mean sizes distribute bimodally or single dominantly with respect to sputtering process parameter of additional oxygen ratio in Ar and Ge concentrations. Compositional plane of these distribution types reveals that sing...

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Applied Physics Letters : Optimal design of miniaturized thin-film...

By: Jiwen Zhu, Tong Hao, Christopher J. Stevens, and David J. Edwards

Description: This paper investigates the optimal miniaturization of a helical resonator, which is in the form of a two turn helix. We theoretically demonstrate that its outmost dimension can be reduced to below 1% of the free space wavelength at resonance. Maximum miniaturization is achieved at an optimal metallic fill ratio of around 0.2 independent of diameter. Simulation and experimental results were used to validate the theoretical model and explore the miniaturizati...

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Journal of Applied Physics : Electric-field-controlled electron re...

By: Y. Y. Liao, D. S. Chuu, and S. R. Jian

Description: This study investigates phonon-induced electron relaxation in a lateral double quantum dot that is embedded in a suspended slab. Exact calculations are made in electric fields. The dependence of the relaxation rate on the parameters of the dots and the slabs is analyzed. Numerical results indicate that the relaxation rate depends strongly on the phonon character of the slab. Unlike in the bulk environment, phonon-subband quantization clearly influences the b...

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Physics of Plasmas : Consistent solution for space-charge-limited ...

By: Y. Feng and J. P. Verboncoeur

Description: The solution for space-charge-limited (SCL) currents in electron vacuum diodes with monoenergetic initial velocity is extended to the relativistic regime. Two types of solutions are found: Type I corresponds to zero steady state surface electric field (field emission with high enhancement factor), and Type II corresponds to a finite steady state surface electric field (other emission mechanisms). Our solution compares well to the classical space-charge-limit...

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Biblioteca Hispanica : the Universe in Your Pocket Useful Knowledg...

By: Biblioteca Hispanica

Description: Astronomy, Natural science.

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