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31.
Katarzyna Raulin Odile Cristini-Robbe Patrice Baldeck Olivier Stéphan Christophe Kinowski Sylvia Turrell Bruno Capoen Mohamed Bouazaoui 《Journal of nanoparticle research》2010,12(4):1459-1467
A novel method for direct laser writing of two-dimensional cadmium sulfide (CdS) semiconductor nanoparticle microstructures
is reported. A two photon or a higher-order multiphoton absorption process, originating from femtosecond laser pulses, was
used to decompose CdS precursors dispersed in a zirconia thin film previously dip-coated on a glass substrate. The kinetics
of nanoparticle formation as a function of laser power were monitored in situ by photoluminescence spectroscopy. Raman spectroscopy
was also performed to characterize the structural changes of the zirconia matrix under irradiation and to verify the formation
of CdS nanoparticles. Results show that CdS nanoparticles were formed by two-photon absorption (TPA) with or without the help
of an additional carbazole photoinitiator. 相似文献
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34.
L. D. Olivier W. A. Richter J. A. Stander J. W. Koen 《Zeitschrift für Physik A Hadrons and Nuclei》1993,347(2):99-108
Levels up to 9.3 MeV excitation in22Ne were studied with the19 F(α, pγ) 22Ne reaction atE α = 12 MeV. Level energies, branching ratios, mean lifetimes, spins and mixing ratios were obtained for a number of levels. Relevant results are compared with many-particle shell-model calculations. 相似文献
35.
Jean-Loïc Rose Alain Lalande Olivier Bouchot El-Bey Bourennane Paul M. Walker Patricia Ugolini Chantal Revol-Muller Raymond Cartier François Brunotte 《Magnetic resonance imaging》2010
Magnetic resonance imaging (MRI) is particularly well adapted to the evaluation of aortic distensibility. The calculation of this parameter, based on the change in vessel cross-sectional area per unit change in blood pressure, requires precise delineation of the aortic wall on a series of cine-MR images. Firstly, the study consisted in validating a new automatic method to assess aortic elasticity. Secondly, aortic distensibility was studied for the ascending and descending thoracic aortas in 26 healthy subjects. Two homogeneous groups were available to evaluate the influence of sex and age (with an age limit value of 35 years). The automatic postprocessing method proved to be robust and reliable enough to automatically determine aortic distensibility, even on artefacted images. In the 26 healthy volunteers, a marked decrease in distensibility appears with age, although this decrease is only significant for the ascending aorta (8.97±2.69 10−3 mmHg−1 vs. 5.97±2.02 10−3 mmHg−1). Women have a higher aortic distensibility than men but only significantly at the level of the descending aorta (7.20±1.61 10−3 mmHg−1 vs. 5.05±2.40 10−3 mmHg−1). Through our automatic contouring method, the aortic distensibility from routine cine-MRI has been studied on a healthy subject population providing reference values of aortic stiffness. The aortic distensibility calculation shows that age and sex are causes of aortic stiffness variations in healthy subjects. 相似文献
36.
We show that, when music pieces are cast in the form of time series of pitch variations, the concepts and tools of dynamical systems theory can be applied to the analysis of temporal dynamics in music. (i) Phase space portraits are constructed from the time series wherefrom the dimensionality is evaluated as a measure of the global dynamics of each piece. (ii) Spectral analysis of the time series yields power spectra ( approximately f(-nu)) close to red noise (nu approximately 2) in the low frequency range. (iii) We define an information entropy which provides a measure of the local dynamics in the musical piece; the entropy can be interpreted as an evaluation of the degree of complexity in the music, but there is no evidence of an analytical relation between local and global dynamics. These findings are based on computations performed on eighty sequences sampled in the music literature from the 18th to the 20th century. (c) 1995 American Institute of Physics. 相似文献
37.
Bernard Masereel Mustapha Dinguizli Caroline Bouzin Nicolas Moniotte Olivier Feron Bernard Gallez Thierry Vander Borght Carine Michiels Stéphane Lucas 《Journal of nanoparticle research》2011,13(4):1573-1580
Nanoscale materials are used in the biomedical field for magnetic resonance imaging, protein detection and drug/gene delivery.
Gold nanoparticles (AuNPs) are particularly investigated in cancer treatment and imaging. In this study, we described a simple
and reliable liquid method to coat AuNPs (diameter: 21 nm) layer-by-layer with alternative cationic polyallylamine and anionic
polystyrenesulfonate. The C-terminal amino acid of the antibody directed against anti-bovine serum albumin was activated by
EDC/NHS, and then condensed with the amino functions of the external polyallylamine layer. An ELISA test confirmed that the
antigen recognition of the bioconjugate antibody was conserved. This AuNP coating and the covalently coupling could be used
as a generic process for binding other specific antibodies, particularly those overexpressed in cancer cells and angiogenesis. 相似文献
38.
Dina Carbone Olivier Plantevin Raul Gago Cristian Mocuta Oier Bikondoa Alejandro Alija Lucien Petit Hamid Djazuli Till‐Hartmut Metzger 《Journal of synchrotron radiation》2008,15(4):414-419
A compact portable vacuum‐compatible chamber designed for surface X‐ray scattering measurements on beamline ID01 of the European Synchrotron Radiation Facility, Grenoble, is described. The chamber is versatile and can be used for in situ investigation of various systems, such as surfaces, nanostructures, thin films etc., using a variety of X‐ray‐based techniques such as reflectivity, grazing‐incidence small‐angle scattering and diffraction. It has been conceived for the study of morphology and structure of semiconductor surfaces during ion beam erosion, but it is also used for the study of surface oxidation or thin film growth under ultra‐high‐vacuum conditions. Coherent X‐ray beam experiments are also possible. The chamber is described in detail, and examples of its use are given. 相似文献
39.
Kumar R Spuesens T Mechet P Kumar P Raz O Olivier N Fedeli JM Roelkens G Baets R Van Thourhout D Morthier G 《Optics letters》2011,36(13):2450-2452
Using a 7.5 μm diameter disk fabricated with III-V-on-silicon fabrication technology, we demonstrate bias-free all-optical wavelength conversion for non-return-to-zero on-off keyed pseudorandom bit sequence (PRBS) data at the speed of 10 Gbits/s with an extinction ratio of more than 12 dB. The working principle of such a wavelength converter is based on free-carrier-induced refractive index modulation in a pump-probe configuration. We believe it to be the first bias-free on-chip demonstration of all-optical wavelength conversion using PRBS data. All-optical gating measurements in the pump-probe configuration with the same device have revealed that it is possible to achieve wavelength conversion beyond 20 Gbits/s. 相似文献
40.
Stanislas Vertu Jens Flügge Jean-Jacques Delaunay Olivier Haeberlé 《Central European Journal of Physics》2011,9(4):969-974
Tomographic Diffractive Microscopy is a technique, which permits to image transparent living specimens in three dimensions
without staining. It is commonly implemented in two configurations, by either rotating the sample illumination keeping the
specimen fixed, or by rotating the sample using a fixed illumination. Under the first-order Born approximation, the volume
of the frequency domain that can be mapped with the rotating illumination method has the shape of a “doughnut”, which exhibits
a so-called “missing cone” of non-captured frequencies, responsible for the strong resolution anisotropy characteristic of
transmission microscopes. When rotating the sample, the resolution is almost isotropic, but the set of captured frequencies
still exhibits a missing part, the shape of which resembles that of an apple core. Furthermore, its maximal extension is reduced
compared to tomography with rotating illumination. We propose various configurations for tomographic diffractive microscopy,
which combine both approaches, and aim at obtaining a high and isotropic resolution. We illustrate with simulations the expected imaging performances of these configurations. 相似文献