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991.
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993.
Muscle metabolic alterations induced by genetic ablation of 4E‐BP1 and 4E‐BP2 in response to diet‐induced obesity 下载免费PDF全文
994.
Lacot E Jacquin O Roussely G Hugon O Guillet de Chatellus H 《Journal of the Optical Society of America. A, Optics, image science, and vision》2010,27(11):2450-2458
For given laser output power, object under investigation, and photodiode noise level, we have theoretically compared the signal-to-noise ratios of a heterodyne scanning imager based on a Michelson interferometer and of an autodyne setup based on the laser optical feedback imaging (LOFI) technique. In both cases, the image is obtained point by point. In the heterodyne configuration, the beating between the reference beam and the signal beam is realized outside the laser cavity (i.e., directly on the detector), while in the autodyne configuration, the wave beating takes place inside the laser cavity and therefore is indirectly detected. In the autodyne configuration, where the laser relaxation oscillations play a leading role, we have compared one-dimensional scans obtained by numerical simulations with different lasers' dynamical parameters. Finally, we have determined the best laser for LOFI applications and the experimental conditions for which the LOFI detection setup (autodyne interferometer) is competitive compared to a heterodyne interferometer. 相似文献
995.
Olivier Kim-Hak Gabriel Ferro Jean Lorenzzi Davy Carole Jacques Dazord Patrick Chaudouët Philippe Miele 《Thin solid films》2010,518(15):4234-3145
The contact between α-SiC crystals and Si-Ge based melts provokes the nucleation of 3C-SiC islands on the crystal surface. Evolution of these islands as a function of various parameters was studied. On both 4H and 6H substrates, it was found that, after nucleation, 3C-SiC islands first enlarge and may form a complete 3C layer under certain conditions. The 3C deposit can then be dissolved by the liquid phase at high temperature or for prolonged contact at relatively moderate temperature. The graphite crucible is proposed to play a central role in these enlargement and dissolution mechanisms by providing extra carbon atoms on the seed surface (enlargement) or provoking thermal induced carbon transport toward the sidewall (dissolution). Several differences between the use of 4H and 6H substrates were also observed. 相似文献
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997.
Mixed‐mode analysis of the sensitivity of a radiofrequency oscillator disturbed by parasitic signals
Christian Gontrand Manel Bouhouche Jos‐Cruz Nuez Perez Olivier Valorge Francis Calmon Jacques Verdier Saïda Latreche 《International Journal of Numerical Modelling》2009,22(1):23-42
The first step of this work is to study the susceptibility of a radiofrequency oscillator to deterministic disturbance sources. A Colpitts oscillator, working around a 4 GHz frequency, contains a heterojunction bipolar transistor with a silicon–germanium base as an active device. A mixed‐mode analysis is involved, applying a microscopic drift diffusion model to the device, whereas the rest of the circuit used is governed by Kirchhoff's laws. We assume that this tool is very relevant to grasp the influence of intrinsic or extrinsic noisy sources of the oscillator. Our first simulation raw results motivate us to discuss, and perhaps extend, via some analytical models, the so‐called impulse sensitivity function model. In this paper, we try to develop quantitative predictions about the phase noise of such oscillators, and to give some new tracks on this field. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
998.
A new way to teach advanced undergraduate and graduate students the theory of estimation and detection is described. The paper shows that the global system mobile (GSM) radio interface is well suited to the teaching of estimation and detection theory because it entails the understanding and application of several concepts within estimation and detection, as well as information theory, signal processing, and radio-wave propagation. With GSM now a mature system with specifications available in the public domain, the students created an open-source (OS) GSM simulator, including all four modulation and coding schemes (MCS 1,2,3,4) with puncturing, a channel estimator, a minimum phase prefilter, a Max log maximum a posteriori probability (MAP) equalizer, and a convolutional decoder. Studying and understanding the theory of estimation and detection is now possible by creating algorithms for the simulator and evaluating the impact of the algorithm on the GSM block error rate (BLER). Several experiments that are possible with the simulator are described. 相似文献
999.
Zhifei Xu Blaise Ravelo Olivier Maurice Sébastien Lalléchère Fayu Wan 《International Journal of Circuit Theory and Applications》2019,47(3):391-405
An analytical modeling method of symmetric tree interconnect is developed in this paper. The tree topology is composed of multibranch distributed interconnects of printed circuit board (PCB). The interconnects are constituted by elementary transmission line (TL) defined by its characteristic impedance and propagation constant. The star symmetric tree model is built with the Kron-Branin (KB) formalism elaborated with the graph topology. Reduction method allowing to simplify the graph from single-input multiple-output (SIMO) to single-input single-output (SISO) circuit is used. The interconnect tree branch currents are determined from the reduced SISO structure. The symmetric tree S-parameter and access and transfer impedance models are expressed in function of constituting elementary TL parameters with the KB formalism. The particular behaviors of short-circuit and open-ended star tree are investigated versus the tree number of output branches. The developed KB model effectiveness is validated with microstrip star tree designed and simulated with a 3D electromagnetic computational and electronic circuit designer commercial tool. Three different proofs of concept (POC) of star trees comprised of three-output, four-output, and five-output branches are computed. The simulated reflection and transmission coefficients from DC to 5 GHz are in good agreement with the KB models. The proposed model is potentially useful for the PCB complex interconnect modeling and signal integrity analysis. 相似文献
1000.
Nicolas Bedon Alexis Bès Olivier Carton Chloé Rispal 《Theory of Computing Systems》2010,46(4):737-760
We prove that every rational language of words indexed by linear orderings is definable in monadic second-order logic. We also show that the converse is true for the class of languages indexed by countable scattered linear orderings, but false in the general case. As a corollary we prove that the inclusion problem for rational languages of words indexed by countable linear orderings is decidable. 相似文献