排序方式: 共有22条查询结果,搜索用时 15 毫秒
1.
Olivas-Gomez O. Simon A. Robertson D. Dombos A. C. Strieder F. Kadlecek T. Hanhardt M. Kelmar R. Couder M. Görres J. Stech E. Wiescher M. 《The European Physical Journal A - Hadrons and Nuclei》2022,58(3):1-18
The European Physical Journal A - Neutron star matter spans a wide range of densities, from that of nuclei at the surface to exceeding several times normal nuclear matter density in the core. While... 相似文献
2.
F. Vanderbist P. Leleux C. Angulo E. Casarejos M. Couder M. Loiselet G. Ryckewaert P. Descouvemont M. Aliotta T. Davinson Z. Liu P. J. Woods 《The European Physical Journal A - Hadrons and Nuclei》2006,27(2):183-186
The 15O(α,α)15O elastic scattering is investigated using a 15O radioactive beam and a He gas cell limited by Mylar windows. The width of a 19Ne state at an excitation energy of 5.35MeV is measured as Γα = 3.2±1.6keV, in agreement with charge symmetry estimate. 相似文献
3.
4.
5.
6.
7.
Hydrodynamic instabilities are usually investigated in confined geometries where the resulting spatiotemporal pattern is constrained by the boundary conditions. Here we study the Faraday instability in domains with flexible boundaries. This is implemented by triggering this instability in floating fluid drops. An interaction of Faraday waves with the shape of the drop is observed, the radiation pressure of the waves exerting a force on the surface tension held boundaries. Two regimes are observed. In the first one there is a coadaptation of the wave pattern with the shape of the domain so that a steady configuration is reached. In the second one the radiation pressure dominates and no steady regime is reached. The drop stretches and ultimately breaks into smaller domains that have a complex dynamics including spontaneous propagation. 相似文献
8.
The cracks observed in the glaze of ceramics form networks, which divide the 2D plane into domains. It is shown that, on the average, the number of sides of these domains is four. This contrasts with the usual 2D space divisions observed in Voronoi tessellation or 2D soap froths. In the latter networks, the number of sides of a domain coincides with the number of its neighbors, which, according to Euler's theorem, has to be six on average. The four sided property observed in cracks is the result of a formation process which can be understood as the successive divisions of domains with no later reorganization. It is generic for all networks having such hierarchical construction rules. We introduce a "geometrical charge," analogous to Euler's topological charge, as the difference from four of the number of sides of a domain. It is preserved during the pattern formation of the crack pattern. 相似文献
9.
10.
A self-adaptative oscillator 总被引:2,自引:0,他引:2
A. Boudaoud Y. Couder M. Ben Amar 《The European Physical Journal B - Condensed Matter and Complex Systems》1999,9(1):159-165
The dynamics of a system where a mass is free to slide on a vibrating string is investigated as the excitation frequency is
varied. One degree of freedom is thus added to the system studied by Helmholtz in which a mass was fixed on a vibrating string.
This new system exhibits a specific dynamics characterized by the existence of a self- adaptative behaviour. When the driving
frequency falls into wide and well defined frequency bands, a long transient is observed by which the mass adjusts its position
so that the whole system becomes resonant. In the gaps between these bands, bifurcations give other equilibrium positions.
A theoretical model is proposed. It accounts for all the experimental results. In the case where two masses are present on
the string, two degrees of freedom are added and the set of equilibrium positions would be expected to be infinite. However,
in the experiment, the two masses are observed to go to positions where they are symmetrical with respect to the middle of
the string. A selection mechanism due to the string stretching is pointed out.
Received 15 October 1998 相似文献