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Osman M. Kamel 《Earth, Moon, and Planets》1988,43(3):271-273
A method to calculate secular terms of the two parts of the planetary disturbing function— when it is expressed in terms of the true anomalies or the eccentric anomalies instead of the mean anomalies - is described. Also an alternative method is outlined. 相似文献
84.
We generalize our results of a second order Jupiter-Saturn planetary theory to be applicable for the case of the four major planets.We use the Von Zeipel method and we neglect powers higher than the third with respect to the eccentricities and sines of the inclinations in our expansions. We consider the critical terms as the only periodic terms. 相似文献
85.
We expand the principal part of the planetary disturbing function, by Smart's method, using Taylor's theorem. In our expansion we neglect terms of degree higher than the fourth in the eccentricities and tangents of the inclinations.Now at the JPL Pasadena, California. 相似文献
86.
Afif Belkacem Kamel Besbes Jacques Chatillon Manell E. Zakharia 《Oceanic Engineering, IEEE Journal of》2006,31(3):614-627
The paper deals with a new concept of imaging technique based on planar synthetic aperture sonar (P-SAS). P-SAS processing takes advantage of the overlap of both ping-to-ping and track to track footprints to improve the imaging resolution in both directions. After describing the method, its implementation is discussed. The exact implementation [three-dimensional (3-D)] is defined and an approximated and faster approach [2timestwo-dimensional (2-D)] is then proposed. The gain in computation time and the possible loss in performances (resolutions, echo amplitude) are investigated by simulating a simple point target. The point spread function is studied in details. The new concept is finally validated by tank experiments (scale about 100) for both proud and buried target imaging 相似文献
87.
Moh-Amokrane Aitouche Mabrouk Djeddi Kamel Baddari 《Arabian Journal of Geosciences》2013,6(7):2183-2192
The most of shallow earthquakes are followed, just after the main shock, by increased residual seismicity known as “aftershocks” or “aftershock sequences”. Because of their disparity in time and space, aftershock sequences are more or less obvious and their productivity is spread out in time. Several studies have been regularly proposed to explain or to understand the mechanisms of the occurrence and the behaviour of these small earthquakes. In a theoretical context, many factors can induce the aftershock triggering: residual friction, subcritical crack growth, pore fluid flow etc. Just after the occurrence of the most destructive main shock of the 21 May 2003 Boumerdes (Algeria) earthquake, a wide sequence of aftershocks was recorded at different geographical locations and with various magnitudes. Based on the fact that the region of Boumerdes (40 km east of the capital Algiers) did not develop major earthquakes in the past, a geostatistical investigation of the data for this aftershock sequence is a valuable input for better seismogeological identification of this area. In the present analysis, after an overview of the geological factors in the likely occurrence of the earthquake, fundamental statistical parameters were chosen: the b value from the Gutenberg–Richter law, the p factor of the extracted respectively from the b value and the fractal variogram defined as a graphic tool to describe the continuity or the roughness of data. Jointly to the geostatistical parameters provided by the variogram like the fractal dimension. The main objective of the calculation and interpretation of these parameters is oriented towards a better understanding of the seismicity of the region of Boumerdes (Algeria) now classified as seismogenic zone. 相似文献
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89.
Nadjinangar Gotoum Kamel Hammami L. C. Owono?Owono Nejm-Eddine Jaidane 《Astrophysics and Space Science》2012,337(2):553-561
Rotational excitation cross sections and rate coefficients of AlF collisions with para-H2 are computed at low temperature, i.e., for T≤70 K. Prior to collisional calculations, a four-dimensional (4D) potential energy surface (PES) for the AlF-H2 system is calculated at the ab initio Coupled-Cluster level of the theory with an aug-cc-pVQZ Gaussian basis set. This 4D-PES is further reduced to a two-dimensional
(2D) PES based on the considerations related to collisional studies with para-H2. The [Al-F] and [H-H] bond lengths are frozen at their experimental equilibrium value r
e
=1.654369 bohr and r
e
=1.4011 bohr respectively. The interaction energy presents a global minimum located ∼63 cm−1 below the AlF-H2 dissociation limit. With this PES, cross sections are determined in the Close-Coupling (CC) approach and rate coefficients
are inferred by averaging the cross sections over a Maxwell-Boltzman distribution of kinetic energies. These quantities are
significantly magnified in comparison with their AlF-He counterparts. The already observed propensity towards ΔJ=1 transitions for AlF-He remains. 相似文献
90.