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51.
52.
A discussion on the use of Auger electron spectroscopy as a quantitative tool to determine the growth mode of metals on single crystal oxide surfaces is presented. In the case of Pd grown epitaxially on MgO(100), the three-dimensional character of the growth is easily seen at coverage above one monolayer. However, in the submonolayer regime, and mainly at low substrate temperatures, the AES results are ambiguous. The combination of AES with the more sensitive helium-atom diffraction method allows us to demonstrate that the growth is three-dimensional from the early stages, the particles becoming flatter when the substrate temperature decreases. We compare our results with other growth studies on different metal/oxide systems. At low temperature, the ideal growth modes are not always observed, the final morphology of the films being determined mainly by kinetic effects. Thus a pseudo-Stranski-Krastanov growth mode is often obtained with formation of 2D islands followed by 3D clustering from a critical submonolayer coverage. 相似文献
53.
Laux S Lureau F Radier C Chalus O Caradec F Casagrande O Pourtal E Simon-Boisson C Soyer F Lebarny P 《Optics letters》2012,37(11):1913-1915
Transverse parasitic lasing is well known for limiting the signal gain and the pulse energy that can be extracted from Ti:sapphire petawatt amplifiers. We have developed a technique for suppressing these parasitic lasing modes based on perfect refractive index-matching liquid doped with a broad-bandwidth absorber to suppress the transverse lasing while ensuring proper heat removal from the Ti:sapphire crystal. The 800 nm laser output with a bandwidth of 41 nm (FWHM) and peak energy of 22.7 J at a repetition rate of 1 Hz is demonstrated. 相似文献
54.
Isotope effects in water as investigated by neutron diffraction and path integral molecular dynamics
Zeidler A Salmon PS Fischer HE Neuefeind JC Simonson JM Markland TE 《J Phys Condens Matter》2012,24(28):284126
The structures of heavy and light water at 300?K were investigated by using a joint approach in which the method of neutron diffraction with oxygen isotope substitution was complemented by path integral molecular dynamics simulations. The diffraction results, which give intra-molecular O-D and O-H bond distances of 0.985(5) and 0.990(5)??, were found to be in best agreement with those obtained by using the flexible anharmonic TTM3-F water model. Both techniques show a difference of ??0.5% between the O-D and O-H intra-molecular bond lengths, and the results support a competing quantum effects model for water in which its structural and dynamical properties are governed by an offset between intra-molecular and inter-molecular quantum contributions. Further consideration of the O-O correlations is needed in order to improve agreement with experiment. 相似文献
55.
56.
In view of applications of SiOxNy thin films in MOEMS technology, a study of the optomechanical characteristics of the PECVD deposited material are investigated. To optimize the quality of SiOxNy layers we establish the relationship between the chemical properties, optical performances, micromechanical stress, and growth parameters of deposited films. To use the SiOxNy thin film for the core layer of a strip-loaded waveguide, we propose preparation conditions of SiOxNy that offer a low-loss optical waveguide with well-controlled refractive index, based on a low-internal stress multilayer structure. 相似文献
57.
V. Da Costa Y. Henry F. Bardou M. Romeo K. Ounadjela 《The European Physical Journal B - Condensed Matter and Complex Systems》2000,13(2):297-303
Tiny spatial fluctuations of tunnel barrier parameters are shown to have dramatic consequences on the statistical properties
of quantum tunneling. A direct experimental evidence is provided that the tunnel current through metal-oxide junctions, imaged
at a nanometric scale, exhibits broad statistical distributions extending over more than 4 orders of magnitude. Striking effects
of broad current distributions are shown: the total tunnel transmission is dominated by few highly transmitting sites and
the typical current density varies strongly with the size of the junction. Moreover, self-averaging of the tunnel current
fluctuations occurs only for unexpectedly large junction areas.
Received 1 April 1999 相似文献
58.
59.
Elaine Smith Margaretta Taylor Maria Mendoza Julie Barkmeier Jon Lemke Henry Hoffman 《Journal of voice》1998,12(2):223-232
Patients at a university voice disorder clinic diagnosed with spasmodicdysphonia (SD, n = 68) or vocal fold paralysis (VFP, n = 57) reported vocal symptoms and adverse work outcomes in contrast to a nondisordered group (ND, n = 68). Patients with SD most frequently cited symptoms of effortfulness (57%) and weakness (54%), VFP cited hoarseness (70%) and weakness (60%), while the nondisordered reported hoarseness (28%). SD and VFP produced greater (p<.05) adverse work outcomes than the nondisordered in the past (SD: 65%, VFP: 41%, ND: 3%), potential future (SD: 78%, VFP: 65%, ND: 19%), and current job performance (SD: 64%, VFP: 46%, ND: 2%). These disorders significantly disrupt socioeconomic outcomes and research is needed to improve functional ability and quality of life. 相似文献
60.
Physics of Atomic Nuclei - An Erratum to this paper has been published: https://doi.org/10.1134/S1063778822010082 相似文献