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41.
T. M. Healy A. A. Fontaine J. T. Ellis S. P. Walton A. P. Yoganathan 《Experiments in fluids》1998,25(5-6):512-518
In this work, a flow visualization experiment was performed to elucidate features of the retrograde hinge flow through a
5 : 1 scaled model of the Medtronic Parallel bileaflet heart valve. It was hypothesized that this model would provide detailed
flow information facilitating identification of flow structures associated with thrombus formation in this valve. The experimental
protocol was designed to ensure fluid dynamic similarity between the model and prototype heart valves. Flow was visualized
using dye injection. The detailed flow structures observed showed the hinge’s inflow channel was the most suspect region for
thrombus formation. Here a complex helical structure was observed.
Received: 27 October 1997/Accepted: 1 May 1998 相似文献
42.
43.
G.D. Alkhazov R. Beurtey A. Boudard G. Bruge H. Catz A. Chaumeaux P. Couvert J.L. Escudié J.M. Fontaine M. Garçon J. Guyot D. Legrand J.C. Lugol R.M. Lombard M. Matoba Y. Terrien 《Physics letters. [Part B]》1977,67(4):402-404
Elastic scattering of 1.047 GeV protons is studied on the isotopically enriched 58,60,62,64Ni isotopes. A spin independent Glauber theory analysis allowed the extraction of nuclear matter densities for these targets. 相似文献
44.
E. Aprile-Giboni J. Bystricky J. Deregel PH. Drompt C. Eisenegger J.M. Fontaine E. Heer R. Hess S. Jaccard F. Lehar W.R. Leo S. Mango S. Morenzoni Y. Onel F. Perrot D. Rapin J. Vrzal J. Yonnet 《Nuclear Physics A》1984,431(4):637-668
The main structure around m = 2.15 GeV first observed by the Argonne group in the spin-dependent total cross section ΔσL is confirmed in the energy range available at SIN. A simultaneous study of the scattered particles at small angles has been carried out with success and gave the spin-correlation parameter A00kk for the pp elastic scattering and for the reaction pp → π+d. The contribution of the 3-body reactions to this spin-dependent total cross section has been deduced and found to be lower than the contribution of the π+d reaction even at 583 MeV. 相似文献
45.
The trajectory of a charged test particle under a Lorentz force is obtained as the geodesic of a riemannian four dimensional manifold. Originally, the geodesic equation is nonlinear in some vector field A′μ. The nonlinearity is traded in for the correct characteristic of the test particle through a gauge condition, imposed upon A′μ, which turns the geodesic into the fully covariant linear and gauge invariant Lorentz equation. Fitting the ratio inside the gauge leaves F′μν independent of and allows its identification with the E.-M. tensor Fμν. This four dimensional approach allows the identification of the fifth coordinate used in Kaluza's geometrization |1,2|. The gauge function appears as the sum of Hamilton-Jacobi function plus an additional term, related to the “length” of the trajectory. It is this latter term which guarantees the correct “normalisation” of the ratio. 相似文献
46.
Jean Bricmont Jean-Raymond Fontaine Joel L. Lebowitz Elliott H. Lieb Thomas Spencer 《Communications in Mathematical Physics》1981,78(4):545-566
We prove that the expansion in powers of the temperatureT of the correlation functions and the free energy of the plane rotator model on ad-dimensional lattice is asymptotic to all orders inT. The leading term in the expansion is the spin wave approximation and the higher powers are obtained by the usual perturbation series. We also prove the inverse power decay of the pair correlation at low temperatures ford=3.Supported by NSF Grant No. MCS 78-01885Supported by NSF Grant No. PHY 78-15920Supported by NSF Grant No. DMR 73-04355Supported by NSF Grant No. PHY-7825390 A01On leave from: Institut de Physique Théorique, Université de Louvain, BelgiumAlso: Department of Physics 相似文献
47.
M. Della Negra D. Drijard H.G. Fischer G. Fontaine H. Frehse P. Frenkiel G. Ghesquière R. Gokieli P. Hanke P.G. Innocenti W. Isenbeck E.E. Kluge V. Korbel S. Krzywdzinski D. Linglin A. Minten D.R.O. Morrison A. Putzer D. Wegener 《Physics letters. [Part B]》1975,59(4):401-404
Events with a positive particle of large transverse momentum emitted at medium angles have been studied using the split field magnet spectrometer at the CERN-ISR at a c.m. energy of √s = 52.5 GeV. Positive particles with large longitudinal momentum, |x| > 0.5, i.e., leading particles, associated to large pT events, are analysed. 相似文献
48.
J.M. Fontaine O. Lee-Deacon J.P. Duraud S. Ichimura C. Le Gressus 《Surface science》1982,122(1):40-54
The damaging effects of electron beams during the acquisition of electron spectra have long been an obstacle in surface analysis. In order to understand the physico-chemical processes which take place under electron irradiation in an AlO system, we have carried out an experiment in which artifices, such as heating, charging, and gas contamination, were absent. We have observed with Auger Electron Spectra increases of the oxidation extent and the oxygen concentration on an oxygen exposed (111) textured polycrystalline surface under electron irradiation (5 keV, 9 × 10?5 A/cm2). These increases were not observed on a clean surface, and were very feeble on a (100) single crystal surface. The increase of oxygen concentration was independent of residual gas pressure (3 × 10?9 to 6 × 10?10 Torr) and its composition; and therefore cannot be explained by gas contamination during the experimental period (about 70 min). We attribute the increase of oxidation degree to the transition of chemisorbed oxygen atoms into oxide through direct momentum transfer from the incident electrons. We suggest that the increase of oxygen within the irradiated area is due to the surface diffusion of chemisorbed oxygen atoms from outside the irradiated area. These oxygen atoms are excited by the electrons scattered from the vacuum chamber walls and gain energy through Franck-Condon type mechanism. The absence of chemisorbed oxygen atoms on (100) surface explains the near absence of these increases on this surface. 相似文献
49.
R. Bertini R. Beurtey F. Brochard G. Bruge H. Catz A. Chaumeaux J.M. Durand J.C. Faivre J.M. Fontaine D. Garreta C. Gustafsson D. Hendrie F. Hibou D. Legrand J. Saudinos J. Thiron 《Physics letters. [Part B]》1973,45(2):119-122
Angular distribution measurements for elastic and inelastic scattering of 1.04 GeV proton by 12C, 58Ni and 208Pb with an energy resolution of the order of 100 keV are presented. 相似文献
50.
Michle Fontaine Joseph Delhalle Mireille Defranceschi Grard Lcayon Jacques Boissel 《International journal of quantum chemistry》1993,46(1):171-181
3-21G RHF calculations on (CF3)2O and (CF3)2OH+ molecules are carried out to assess the changes induced in the molecular properties of ether links in poly (perfluoro ethers) interacting with acid sites at contact surfaces. Geometry of the species, vibrational frequencies, proton affinity, and energetics of the (CF3)2OH+ fragmentation provide a preliminary basis to understand problems raised by lubricant degradation. © 1993 John Wiley & Sons, Inc. 相似文献