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991.
At ONERA-Lille center a lot of studies have been conducted to characterize complex flows using an optical method based on
differential interferometry with Wollaston prism and white polarized light source. Several applications are presented in two-dimensional
and axisymmetric flows and in a gaseous mixture where the two gases interface is submitted to acceleration. Then, real-time
color holographic interferometry (RCHI) has been developed to obtain the refractive index itself in two dimensional wake flow.
The last improvements concern the extension of this method for analyzing three dimensional flows. The authors present a specific
setup defined in a single sight direction, the aim being to reproduce the same optical setup along several sight directions,
each shifted by a given angle. This optical technique uses reflection holograms where the diffraction efficiency of plates
is strongly influenced by the variations in the gelatin thickness produced during the holograms treatment. Problems are discussed
and solutions are proposed to control the gelatin shrinkage for two different types of used holograms. The results obtained
in a one sight direction make it possible to build in the future an optical setup allowing several simultaneous line-of-sight
optical measurements. 相似文献
992.
D. Fong J. H. Hamilton A. V. Ramayya J. K. Hwang C. Goodin K. Li J. Kormicki J. O. Rasmussen Y. X. Luo S. C. Wu I. Y. Lee A. V. Daniel G. M. Ter-Akopian G. S. Popeko A. S. Fomichev A. M. Rodin Yu. Ts. Oganessian M. Jandel J. Kliman L. Krupa J. D. Cole M. A. Stoyer R. Donangelo W. C. Ma 《Physics of Atomic Nuclei》2006,69(7):1161-1167
The hot bimodal fission of 252Cf is reexamined with new high-statistics data. We constructed a γ-γ-γ coincidence cube for binary fission and LCP-gated γ-γ matrix for ternary fission. By identifying the secondary fission fragments from their γ-ray transitions, we measured the yields for various fission splits. The normal neutron yield distribution is found to be
Gaussian for Xe-Ru. However, the binary fission split of Ba-Mo is found to exhibit a bimodal neutron distribution with the
“hot mode” corresponding to ≈3.1% of the total yield. In α ternary fission, the first measurements of yields for specific fission splits are presented. The Te-α-Ru and Xe-α-Mo neutron yields fit well with a single mode, but the Ba-α-Zr split shows evidence for an enhanced hot mode with an intensity of ≈13.8% of the normal mode.
The text was submitted by the authors in English. 相似文献
993.
A. G. Zhdanov A. K. Zvezdin A. P. Pyatakov T. B. Kosykh D. Viehland 《Physics of the Solid State》2006,48(1):88-95
The specific features of the “incommensurate-commensurate” phase transitions induced by a magnetic field in multiferroics
(materials with coexisting magnetic and electric ordering) are considered. These materials are ferroelectromagnets, for example,
bismuth ferrite BiFeO3 and BiFeO3-based compounds, which have spatially modulated spin structures. It is shown that the interaction between the electric and
magnetic subsystems of the multiferroic material can lead to an electric-field-induced shift of the critical magnetic field
corresponding to the transition from a spatially modulated state to a homogeneous antiferromagnetic state. According to the
theoretical estimates obtained for material parameters characteristic of the bismuth ferrite, this shift is of the order of
0.5 T in an electric field of 50 kV/cm. The phase diagrams are constructed in the “electric field-magnetic field” coordinates.
The results of calculations performed in the harmonic incommensurate structure approximation are compared with the exact soliton
solution. 相似文献
994.
A nanoscale
multivalent platinum drug based on a poly(amidoamine) [PAMAM] dendrimer (generation
4.5, carboxylate surface) has been synthesized and fully characterized using
a variety of spectroscopic, chromatographic and thermal methods. Treatment
of the dendrimer with an aqueous solution containing an excess diaquo(cis-1,2-diaminocyclohexane)platinum(II) produces
a conjugate containing approximately forty (diaminocyclohexane)platinum(II)
moieties at the surface of the dendrimer. This material undergoes smooth two-stage
thermal decomposition to provide residual platinum oxide reflecting the platinum
loading in the drug. 相似文献
995.
A. Yu. Shvykin V. V. Platonov V. A. Proskuryakov K. B. Chilachava S. I. Podshibyakin 《Russian Journal of Applied Chemistry》2006,79(10):1576-1580
A method of synthesis of acetylacetonated humin-like compounds was developed. The effect of modification on the sorption capacity of humin-like compounds with respect to heavy metals was studied. 相似文献
996.
A. P. Suponina L. G. Kolzunova M. A. Karpenko 《Russian Journal of Applied Chemistry》2006,79(6):924-929
The effect of coatings based on a copolymer of acrylamide, N,N′-methylenebisaxcrylamide and formaldehyde deposited by electrochemical polymerization on the corrosion resistance of 08Kh18N10T stainless steel (field studies at sea) and low-carbon steel (laboratory experiments) was examined. 相似文献
997.
C V Fabritius N L Madsen J Clausen J Larsen 《The Journal of the Operational Research Society》2006,57(12):1482-1490
An ontology is a classification model for a given domain. In information retrieval, ontologies are used to perform broad searches. An ontology can be visualized as nodes and edges. Each node represents an element and each edge a relation between a parent and a child element. Working with an ontology becomes easier with a visual representation. An idea is to use the expressive power of 3D representation to provide visualization for the user. In this paper, we propose a new method for positioning the elements of the visualized concept lattice in the 3D world based on operations research (OR) methods. One method uses a discrete location model to create an initial solution and we propose heuristic methods to further improve the visual result. We evaluate the visual results according to our success criteria and the feedback from users. Running times of the heuristic indicate that an improved version should be feasible for on-line processing and what-if analysis of ontologies. 相似文献
998.
In this work, the optical and structural properties of high k materials such as tantalum oxide and titanium oxide were studied by spectroscopic ellipsometry, where a Tauc-Lorentz dispersion model based in one (amorphous films) or two oscillators (microcrystalline films) was used. The samples were deposited at room temperature by radio frequency magnetron sputtering and then annealed at temperatures from 100 to 500 °C. Concerning the tantalum oxide films, the increase of the annealing temperature, up to 500 °C does not change the amorphous nature of the films, increasing, however, their density. The same does not happen with the titanium oxide films that are microcrystalline, even when deposited at room temperature. Data concerning the use of a four-layer model based on one and two Tauc-Lorentz dispersions is also discussed, emphasizing its use for the detection of an amorphous incubation layer, normally present on microcrystalline films grown by sputtering. 相似文献
999.
O.E. Petrova N.B. Tarasova A.Ju. Alyabyev M.N. Davydova N.L. Loseva 《Thermochimica Acta》2006,445(1):67-69
Calorimetric results indicate that nitrocellulose (NC)-induced changes in the metabolism of Desulfovibrio desulfuricans 1388 are caused by both chemical (nitrate) and physical (biofilm formation) factors. Nitrate added to lactate-based culture medium with nitrocellulose competed for the electron flux from lactate and suppressed the bacterial sulfidogenesis and growth. The presence of an insoluble compound (carbon backbone of the polymer) induced the creation of a biofilm-like structure with its own metabolism. 相似文献
1000.
The oxide films formed on AISI 304L stainless steel at 300 °C in the oxidation time range between 2 and 4 h have been studied by photoelectrochemistry. Photocurrents were investigated as a function of the wavelength of the incident light and the electrode potential. The investigation allowed the determination of the semiconductive properties of the oxides. The oxide films showed n-type behaviour. A duplex structure of the oxide films has been suggested on the basis of the photocurrent spectra, with an internal oxide layer having an optical gap (Eg2 = 2.16-2.3 eV) depending on the applied potential and oxidation time, higher to that of the external oxide layer (Eg1 ≈ 1.9 eV). Significant variations in the amplitude of the photocurrent were detected as a function of the applied potential and the oxidation time. 相似文献