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41.
Photometric observations of symbiotic stars in the blue and in the red spectral regions make it possible to reveal non-radial
oscillations both of the cool and of the hot components. Light variations of red giants in the symbiotic systems CI Cyg and
AG Peg show several periods in the 10–80d range, interpreted as p-mode pulsations. These modes are excited by a bright spot produced by radiation flux from the hot
component. The spot moves on the red giant’s photosphere at a velocity close to the sound speed. During the active phase of
the symbiotic star CH Cyg, at least 25 frequencies of oscillations in the 150–6000 s range of periods were found in the light
of the white dwarf. Their features correspond to non-radial g-modes. In the frame of 2D gas dynamical non-adiabatic models,
the interaction between gas flows and the accretion disk leads to formation of a system of shock waves propagating towards
the compact object, which is one of possible mechanisms to excite non-radial pulsations of white dwarfs in symbiotic systems. 相似文献
42.
Active regions on the Sun in the 20th solar cycle are studied with special reference to their association with proton flares based on microwave interferometric observations at Toyokawa Observatory. It has been reconfirmed that the active regions associated with intense S-component emission with a high 3-cm to 8-cm flux ratio are likely to produce proton flares. About one fourth of 259 active regions during the period investigated are found to have definite features in the spatial distribution of polarization at a wavelength of 3 cm. Active regions with one particular type of polarization pattern have a good correlation with the occurrence of proton flares. 相似文献
43.
44.
Bálint Érdi 《Celestial Mechanics and Dynamical Astronomy》1982,28(1-2):209-218
Szebehely's equation for the potential generating a prescribed family of orbits in two dimensions is generalized for three-dimensional orbits. A simultaneous system of first-order linear partial differential equations is derived for the determination of the potential in the three-dimensional case. Solutions of this system are found in several cases including Kepler's problem too.Paper presented at the 1981 Oberwolfach Conference on Mathematical Methods in Celestial Mechanics.This paper is dedicated to Professor Victor Szebehely on the occasion of his 60th birthday. 相似文献
45.
46.
B. Smodiš M. L. Pignata M. Saiki E. CortÉs N. Bangfa B. Markert B. Nyarko J. Arunachalam J. Garty M. Vutchkov H. Th. Wolterbeek E. Steinnes M. C. Freitas A. Lucaciu M. Frontasyeva 《Journal of Atmospheric Chemistry》2004,49(1-3):3-13
The International Atomic Energy Agency (IAEA) organized a co-ordinated research project (CRP) on Validation and application of plants as biomonitors of trace element atmospheric pollution analysed by nuclear and related techniques involving 14 participating countries. The CRPs objective was to identify appropriate bioindicators for local and/or regional application and validate them for general air pollution monitoring. Activities included quantification studies, research into spatial and time resolution for particular organisms, and physiological studies. A number of suitable bioindicators were identified in different parts of the globe and tested during the CRP. Sampling strategies were reviewed and the recommended approach adopted by the group. Appropriate sample preparation procedures were assessed and harmonised to the degree allowed by different geographic and climatic conditions in the participating countries. Two interlaboratory comparison exercises were carried out on lichen and moss materials. Results confirmed definite improvement in analytical performance of the participating laboratories, but also revealed possible inconsistencies due to different sample processing procedures. Several monitoring surveys were carried out and consequently pollution maps drawn for extended areas or countries. Overall results confirmed applicability of lower plants for assessing the degree of atmospheric pollution and provided several countries with effective monitoring tools not used before. 相似文献
47.
48.
In this work, we analyze nuclear effects in the inclusive production of quarkonium in proton-nucleus collisions at high energy regime. A theoretical framework that includes initial state effects like nuclear shadowing and gluon density saturation is considered. Numerical results for nuclear modification factor, , as a function of meson rapidity in proton-nucleus collisions are presented. The parameter-free predictions are compared to the available data from the Large Hadron Collider. Discussion on the main theoretical uncertainties is made, with emphasis on the phenomenological models for the nuclear saturation scale. 相似文献
49.
Bálint Érdi Emese Forgács-Dajka Imre Nagy Renáta Rajnai 《Celestial Mechanics and Dynamical Astronomy》2009,104(1-2):145-158
The size of the stable region around the Lagrangian point L 4 in the elliptic restricted three-body problem is determined by numerical integration as a function of the mass parameter and eccentricity of the primaries. The size distribution of the stable regions in the mass parameter-eccentricity plane shows minima at certain places that are identified with resonances between the librational frequencies of motions around L 4. These are computed from an approximate analytical equation of Rabe relating the frequency, mass parameter and eccentricity. Solutions of this equation are determined numerically and the global behaviour of the frequencies depending on the mass parameter and eccentricity is shown and discussed. The minimum sizes of the stable regions around L 4 change along the resonances and the relative strength of the resonances is analysed. Applications to possible Trojan exoplanets are indicated. Escape from L 4 is also investigated. 相似文献
50.
Previous “fraction of young water” (Fyw) estimates based on relative annual isotopic amplitudes in precipitation (Ap) and streamflow (As) produced low Fyw values in mountain catchments, which is contrary to extensive research that reports rapid water transmission in mountains. This study investigated this discrepancy by testing the effect of snow accumulation on the model that underpins the Fyw method. A Monte-Carlo analysis of simulations for 20,000 randomly-generated catchment model configurations used 10 years of precipitation inputs for the Upper Elbow River catchment in the Rocky Mountains (Alberta, Canada) to model discharge with and without snowpack storage of winter precipitation. Neither direct nor modified precipitation input produced a 1:1 relationship between As/Ap and Fyw, undermining the applicability of the original Fyw method in mountain watersheds with large seasonal snow accumulation. With snowpack-modified input a given As/Ap ratio corresponds to a range of Fyw values, which can still provide semi-quantitative information. In the small (435 km2) Elbow River catchment a Fyw range of 7–23% supports previous findings of rapid transmission in mountain catchments. Further analysis showed that the improved discharge prediction (Nash–Sutcliffe efficiency > 0.9) correlates with higher Fyw values and demonstrated that the interannual shifts in δ18O can be used to estimate of new water (<1 year) fraction in winter streamflow, and the estimate of 20% for the Elbow River further supports rapid transmission in mountain catchments. 相似文献