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151.
152.
A reduction method is worked out for determining a class of exact solutions with inherent wave features to quasilinear hyperbolic homogeneous systems of N>2 first-order autonomous PDEs. A crucial point of the present approach is that in the process the original set of field equations induces the hyperbolicity of an auxiliary 2×2 subsystem and connection between the respective characteristic velocities can be established. The integration of this auxiliary subsystem via the hodograph method and through the use of the Riemann invariants provides the searched solutions to the full governing system. These solutions also represent invariant solutions associated with groups of translation of space/time coordinates and involving arbitrary functions that can be used for studying non-linear wave interaction. Within such a theoretical framework the two-dimensional motion of an adiabatic fluid is considered. For appropriate model pressure-entropy-density laws, we determine a solution to the governing system of equations which describes in the 2+1 space two non-linear waves which were initiated as plane waves, interact strongly on colliding but emerge with unaffected profile from the interaction region. These model material laws include the classical pressure-entropy-density law which is usually adopted for a polytropic fluid. 相似文献
153.
I. Fonseca N. Fusco G. Leoni M. Morini 《Archive for Rational Mechanics and Analysis》2007,186(3):477-537
Strained epitaxial films grown on a relatively thick substrate are considered in the context of plane linear elasticity. The
total free energy of the system is assumed to be the sum of the energy of the free surface of the film and the strain energy.
Because of the lattice mismatch between film and substrate, flat configurations are in general energetically unfavorable and
a corrugated or islanded morphology is the preferred growth mode of the strained film. After specifying the functional setup
in which the existence problem can be properly framed, a study of the qualitative properties of the solutions is undertaken.
New regularity results for volume-constrained local minimizers of the total free energy are established, leading, as a byproduct,
to a rigorous proof of the zero-contact-angle condition between islands and wetting layers. 相似文献
154.
In this paper, the design requirements of an experimental apparatus for the measurement of the direct derivatives on an oscillating aircraft model in a wind tunnel are discussed. The elaboration of the signal output of the force transducer is analysed, according to the direct forced oscillation technique. The distorsions of the primary oscillatory motion were previously evaluated and corrected, adopting an open loop control technique. This algorithm is presented and its reliability is verified. Finally, the behaviour of the experimental stability parameters, adopting different oscillation amplitudes and frequencies, is discussed.
Sommario Nel presente lavoro vengono analizzate le principali caratteristiche di un sistema per l'esecuzione delle prove di oscillazione forzata in galleria del vento, al fine di valutare le derivate aerodinamiche dirette, secondo i gradi di libertá alla rotazione di un velivolo. Inizialmente l'attenzione viene concentrata sul principio di funzionamento e sull'algoritmo di elaborazione dei segnali estensimetrici. L'analisi procede quindi con lo studio delle caratteristiche cinematiche del sistema di movimentazione e supporto, ed in particolare si discutono lc problematiche connesse con il controllo del moto oscillatorio del modello. Infine, viene discusso l'utilizzo dell'apparecchiatura in oggetto con lo acopo di evidenziare come i parametri di stabilitá rilevati sperimentalmente dipendano daile caratteristiche del moto armonico di forzamento.相似文献
155.
Akindinov A.N. Alici A. Anselmo F. Antonioli P. Baek Y. Basile M. Romeo G. Cara Cifarelli L. Cindolo F. Cosenza F. Caro A. De Pasquale S. De Bartolomeo A. Di Girard M. Fusco Guida M. Hatzifotiadou D. Kaidalov A.B. Kim D.W. Kim D.H. Kisselev S.M. Laurenti G. Lee K. Lee S.C. Lioublev E. Luvisetto M.L. Margotti A. Martemiyanov A.N. Nania R. Noferini F. Otiougova P. Pierella F. Polozov P.A. Scapparone E. Scioli G. Sellitto S.B. Smirnitski A.V. Tchoumakov M.M. Valenti G. Vicinanza D. Voloshin K.G. Williams M.C.S. Zagreev B.V. Zampolli C. Zichichi A. 《The European Physical Journal C - Particles and Fields》2004,34(1):s325-s331
The European Physical Journal C - The ALICE TOF array will be built using the Multigap Resistive Plate Chamber(MRPC) configured as a double stack. Each stack contains 5 gas gaps with width of... 相似文献
156.
Eric Gendron Franois Assmat Franois Hammer Pascal Jagourel Fanny Chemla Philippe Laporte Mathieu Puech Michel Marteaud Frdric Zamkotsian Arnaud Liotard Jean-Marc Conan Thierry Fusco Norbert Hubin 《Comptes Rendus Physique》2005,6(10):1110-1117
FALCON is a wide-field, multi-object integral field spectrograph equipped with adaptive optics. It is dedicated to the study of the formation process of primordial galaxies. The AO system uses natural guide stars, and the high sky coverage required for these studies is obtained using tomographic techniques for the wavefront analysis. The structure of the OA system is very new, and particularly suited for a future implementation on extremely large telescopes. To cite this article: E. Gendron et al., C. R. Physique 6 (2005). 相似文献
157.
Ferrario M Alesini D Bacci A Bellaveglia M Boni R Boscolo M Castellano M Catani L Chiadroni E Cialdi S Cianchi A Clozza A Cultrera L Di Pirro G Drago A Esposito A Ficcadenti L Filippetto D Fusco V Gallo A Gatti G Ghigo A Giannessi L Ligi C Mattioli M Migliorati M Mostacci A Musumeci P Pace E Palumbo L Pellegrino L Petrarca M Quattromini M Ricci R Ronsivalle C Rosenzweig J Rossi AR Sanelli C Serafini L Serio M Sgamma F Spataro B Tazzioli F Tomassini S Vaccarezza C Vescovi M Vicario C 《Physical review letters》2007,99(23):234801
In this Letter we report the first experimental observation of the double emittance minimum effect in the beam dynamics of high-brightness electron beam generation by photoinjectors; this effect, as predicted by the theory, is crucial in achieving minimum emittance in photoinjectors aiming at producing electron beams for short wavelength single-pass free electron lasers. The experiment described in this Letter was performed at the SPARC photoinjector site, during the first stage of commissioning of the SPARC project. The experiment was made possible by a newly conceived device, called an emittance meter, which allows a detailed and unprecedented study of the emittance compensation process as the beam propagates along the beam pipe. 相似文献
158.
Dr. Sandra Fusco Dr. Mario Barra Dr. Lorenzo Gontrani Dr. Matteo Bonomo Dr. Federico Chianese Dr. Simone Galliano Prof. Roberto Centore Prof. Antonio Cassinese Prof. Marilena Carbone Prof. Antonio Carella 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(25):e202104552
Three novel diketopyrrolopyrrole (DPP) based small molecules have been synthesized and characterized in terms of their chemical-physical, electrochemical and electrical properties. All the molecules consist of a central DPP electron acceptor core symmetrically functionalized with donor bi-thienyl moieties and flanked in the terminal positions by three different auxiliary electron-acceptor groups. This kind of molecular structure, characterized by an alternation of electron acceptor and donor groups, was purposely designed to provide a significant absorption at the longer wavelengths of the visible spectrum: when analysed as thin films, in fact, the dyes absorb well over 800 nm and exhibit a narrow optical bandgap down to 1.28 eV. A detailed DFT analysis provides useful information on the electronic structure of the dyes and on the features of the main optical transitions. Organic field-effect transistors (OFETs) have been fabricated by depositing the DPP dyes as active layers from solution: the different end-functionalization of the dyes had an effect on the charge-transport properties with two of the dyes acting as n-type semiconductors (electron mobility up to 4.4 ⋅ 10−2 cm2/V ⋅ s) and the third one as a p-type semiconductor (hole mobility up to 2.3 ⋅ 10−3 cm2/V ⋅ s). Interestingly, well-balanced ambipolar transistors were achieved by blending the most performant n-type and p-type dyes with hole and electron mobility in the order of 10−3 cm2/V ⋅ s 相似文献
159.
160.
Tiziana Calamoneri Emanuele G. Fusco Richard B. Tan Paola Vocca 《Mathematical Methods of Operations Research》2009,69(2):307-321
An L(h, 1, 1)-labeling of a graph is an assignment of labels from the set of integers {0, . . . , λ} to the nodes of the graph such
that adjacent nodes are assigned integers of at least distance h ≥ 1 apart and all nodes of distance three or less must be assigned different labels. The aim of the L(h, 1, 1)-labeling problem is to minimize λ, denoted by λ
h, 1, 1 and called span of the L(h, 1, 1)-labeling. As outerplanar graphs have bounded treewidth, the L(1, 1, 1)-labeling problem on outerplanar graphs can be exactly solved in O(n
3), but the multiplicative factor depends on the maximum degree Δ and is too big to be of practical use. In this paper we give
a linear time approximation algorithm for computing the more general L(h, 1, 1)-labeling for outerplanar graphs that is within additive constants of the optimum values.
This research is partially supported by the European Research Project Algorithmic Principles for Building Efficient Overlay Computers (AEOLUS) and was done during the visit of Richard B. Tan at the Department of Computer Science, University of Rome “Sapienza”, supported
by a visiting fellowship from the University of Rome “Sapienza”. 相似文献