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71.
A. Guertin N. Marie S. Auduc V. Blideanu Th. Delbar P. Eudes Y. Foucher F. Haddad T. Kirchner Ch. Le Brun C. Lebrun F. R. Lecolley J. F. Lecolley X. Ledoux F. Lefèbvres T. Lefort M. Louvel A. Ninane Y. Patin Ph. Pras G. Rivière C. Varignon 《The European Physical Journal A - Hadrons and Nuclei》2005,23(1):49-60
Neutrons and light charged particles produced in 62.9MeV proton-induced reactions on 208Pb were measured during a single experiment performed at the CYCLONE facility in Louvain-la-Neuve (Belgium). Two independent experimental set-ups were used to extract double differential cross-sections for neutrons, protons, deuterons, tritons, 3He and alpha-particles. Charged particles were detected using a set of Si- Si- CsI telescopes from 25° to 155°, by step of 10 degrees. Neutrons were measured using shielded DeMoN counters, liquid NE213 scintillators, at 24°, 35°, 55°, 80° and 120°. These data allowed the determination of angle differential, energy differential and total production cross-sections. A comparison with theoretical calculations (MCNPX, FLUKA and TALYS) has been performed. It shows that the neutron and proton production rates are well predicted by MCNPX, using the INCL4 option. All the other codes underestimate the neutron production whereas they overestimate the proton one. For composite particles, which represent 17% of the charged particle total reaction cross-section, neither the shape nor the amplitude of the cross-sections are correctly predicted by the models. 相似文献
72.
73.
Sénéchal K Toupet L Ledoux I Zyss J Le Bozec H Maury O 《Chemical communications (Cambridge, England)》2004,(19):2180-2181
New push-pull NLO-phores based on lanthanide complexes (Ln = La, Gd, Dy, Yb) featuring an annelated dibutylaminophenyl functionalised terpyridyl ligand have been synthesised and shown to exhibit large first-order hyperpolarizability. 相似文献
74.
Bartholomew GP Ledoux I Mukamel S Bazan GC Zyss J 《Journal of the American Chemical Society》2002,124(45):13480-13485
Six permutations of 4-fold donor and/or acceptor substitution of paracyclophane at the 4, 7, 12, and 15 positions were synthesized to probe the phenomenon of three-dimensional delocalization on the nonlinear optical properties of organic materials. The interplay between through-bond intramolecular charge transfer (ICT) as well as three-dimensional, or through-space, ICT processes gives rise to large quadratic hyperpolarizability values. The determination of dipolar (beta(J)(=1)) and octupolar (beta(J)(=3)) irreducible tensor contributions to the overall beta tensor value is made possible by the polarized harmonic light scattering technique at 1.32 microm. The electric field-induced second-harmonic generation technique was also used at 1.91 microm for comparison. Significant experimental beta values for members of the series made of two centrosymmetric benzene-like units are a clear signature of a purely through-space ICT between two aryl subunits. The two configurational isomers that pair two dipolar donor-acceptor chromophores also exhibit octupolar character. Analysis of these two with an additive model for beta(J)(=1) and beta(J)(=3) reveals a strong three-dimensional inter-ring charge transfer. 相似文献
75.
Phase field modelling has proven to be a versatile tool for simulating microstructural evolution phenomena, such as grain growth in polycrystalline materials. However, the computational requirements of a phase field model impose strong limitations on the number of phase field variables employed in a practical implementation. In this paper, a bounding box algorithm is proposed allowing the use of a large number of phase field variables without excessive computational requirements. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
76.
In this paper, a fractional version of the Clifford-Fourier transform is introduced, depending on two numerical parameters. A series expansion for the kernel of the resulting integral transform is derived. In the case of even dimension, also an explicit expression for the kernel in terms of Bessel functions is obtained. Finally, the analytic properties of this new integral transform are studied in detail. 相似文献
77.
Patrice Mélinon Sylvie Begin-Colin Jean Luc Duvail Fabienne Gauffre Nathalie Herlin Boime Gilles Ledoux Jérôme Plain Peter Reiss Fabien Silly Bénédicte Warot-Fonrose 《Physics Reports》2014
It has been for a long time recognized that nanoparticles are of great scientific interest as they are effectively a bridge between bulk materials and atomic structures. At first, size effects occurring in single elements have been studied. More recently, progress in chemical and physical synthesis routes permitted the preparation of more complex structures. Such structures take advantages of new adjustable parameters including stoichiometry, chemical ordering, shape and segregation opening new fields with tailored materials for biology, mechanics, optics magnetism, chemistry catalysis, solar cells and microelectronics. Among them, core/shell structures are a particular class of nanoparticles made with an inorganic core and one or several inorganic shell layer(s). In earlier work, the shell was merely used as a protective coating for the core. More recently, it has been shown that it is possible to tune the physical properties in a larger range than that of each material taken separately. The goal of the present review is to discuss the basic properties of the different types of core/shell nanoparticles including a large variety of heterostructures. We restrict ourselves on all inorganic (on inorganic/inorganic) core/shell structures. In the light of recent developments, the applications of inorganic core/shell particles are found in many fields including biology, chemistry, physics and engineering. In addition to a representative overview of the properties, general concepts based on solid state physics are considered for material selection and for identifying criteria linking the core/shell structure and its resulting properties. Chemical and physical routes for the synthesis and specific methods for the study of core/shell nanoparticle are briefly discussed. 相似文献
78.
Nele De Schepper Dixan Peña Peña Frank Sommen 《Mathematical Methods in the Applied Sciences》2014,37(17):2704-2715
In this paper, we investigate a Cauchy–Kowalevski (CK) extension problem that arises naturally within the framework of Hermitian Clifford analysis, which concerns the study of Dirac‐like operators in several complex variables. The work presented here includes CK extensions of higher codimension and in particular the CK extension of the Gauss distribution in several complex variables. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
79.
Raquel C. C. Coutinho Jose Carlos Pinto Marcio Nele Andreas Hannisdal Johan Sjöblom 《Journal of Dispersion Science and Technology》2013,34(7):923-934
The critical electrical field has been used as a tool to probe water in crude emulsion stability to electrical fields in many previous studies. Given the increasing importance of this metric, this study investigates factors that are important to the reproducibility of the measurement and the effect of emulsion preparation variables on the critical electric field. It was observed that the emulsion preparation procedure has a strong effect on the measured critical electric field due to droplet size effects. Furthermore, the effect of crude oil properties on the critical electric field was investigated using emulsions from different oils but with the same average droplet diameter, where it was found that the measurement was dominated by crude oil viscosity. 相似文献
80.
Hendrik De Bie Nele De Schepper Frank Sommen 《Journal of Fourier Analysis and Applications》2011,17(6):1198-1231
Recently, there has been an increasing interest in the study of hypercomplex signals and their Fourier transforms. This paper
aims to study such integral transforms from general principles, using 4 different yet equivalent definitions of the classical
Fourier transform. This is applied to the so-called Clifford-Fourier transform (see Brackx et al., J. Fourier Anal. Appl.
11:669–681, 2005). The integral kernel of this transform is a particular solution of a system of PDEs in a Clifford algebra, but is, contrary
to the classical Fourier transform, not the unique solution. Here we determine an entire class of solutions of this system
of PDEs, under certain constraints. For each solution, series expressions in terms of Gegenbauer polynomials and Bessel functions
are obtained. This allows to compute explicitly the eigenvalues of the associated integral transforms. In the even-dimensional
case, this also yields the inverse transform for each of the solutions. Finally, several properties of the entire class of
solutions are proven. 相似文献