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, ii (2000–3000 Å) i . , i . i (. 2). i i i i + ( 7–10). ii (. 13). ii i i (, 2400 Å) (. 14 15). i i i , iu , i (. 1). i i ii i i . .  相似文献   

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Altrock  Richard C. 《Solar physics》2003,213(1):23-37
Synoptic photoelectric observations of the coronal Fexiv and Fex emission lines at 530.3 nm and 637.4 nm, respectively, are analyzed to study the rotational behavior of the solar corona as a function of latitude, height, time and temperature between 1976 (1983 for Fex) and 2001. An earlier similar analysis of the Fexiv data at 1.15 R over only one 11-year solar activity cycle (Sime, Fisher, and Altrock, 1989, Astrophys. J. 336, 454) found suggestions of solar-cycle variations in the differential (latitude-dependent) rotation. These results are tested over the longer epoch now available. In addition, the new Fexiv 1.15 R results are compared with those at 1.25 R and with results from the Fex line. I find that for long-term averages, both ions show a weakly-differential rotation period that may peak near 80° latitude and then decrease to the poles. However, this high-latitude peak may be due to sensing low-latitude streamers at higher latitudes. There is an indication that the Fexiv rotation period may increase with height between 40° and 70° latitude. There is also some indication that Fex may be rotating slower than Fexiv in the mid-latitude range. This could indicate that structures with lower temperatures rotate at a slower rate. As found in the earlier study, there is very good evidence for solar-cycle-related variation in the rotation of Fexiv. At latitudes up to about 60°, the rotation varies from essentially rigid (latitude-independent) near solar minimum to differential in the rising phase of the cycle at both 1.15 R and 1.25 R . At latitudes above 60°, the rotation at 1.15 R appears to be nearly rigid in the rising phase and strongly differential near solar minimum, almost exactly out of phase with the low-latitude variation.  相似文献   

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The applicability of the properties of central configurations proceeding from the many-body problem to study of gaseous sphere cloud evolution during its gravitational contraction is justified. It is shown that the product runs to a constant value in the asymptotic time limit of simultaneous collision of all the particles of the cloud where is a form-factor of the potential energy and is a form-factor of the moment of inertia.The spherical bodies as well as ellipsoids of rotation and general ellipsoids with a one-dimensional mass distribution (k),k[0, 1] are found to possess the property =const.
. , - , , ., , - =const., , (k),k[0, 1].
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, ; . , , , , . . . -. . .
The stability of the stationary motions of a spin-stabilized satellite is investigated using the Lyapunov second method. The nutating motion of the satellite is damped by a special-purpose device. In case the damping device consists of several independent dampers with one degree of freedom little affecting the satellite motion, their optimal parameters ensuring a maximal rate of damping the nutating motion of the satellite are determined with the hypothesis of resonance adjustmentsof the dampers. The Krylov-Bogolyubov method is used to investigate the influence of external moments on the motion of the satellite rotation axis.
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Some particular solutions of the restricted three-body problem which determine outgoing or incoming orbits near libration points are considered. The solutions are obtained in the form of absolutely convergent Liapounov series. It is proved that these asymptotic solutions are plane curves situated in the orbital plane of the primaries. Each family of asymptotic solutions for every collinear point consists of four solutions which are the separatrices of a saddle point. The angles of inclination of the separatrices are determined.
aaa a a aa , a. a a a. a, a . . aa, a a aaa. . a . a a , aaa a. . aa aa a .
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The gravity potential of an arbitrary bodyT is expanded in a series of spherical harmonics and rigorous evaluations of the general termV n of the expansion are obtained. It is proved thatV n decreases on the sphere envelopingT according to the power law if the body structure is smooth. For a body with analytic structure,V n decreases in geometric progression. The exactness of these evaluations is proved for bodies having irregular and analytic structures. For the terrestrial planetsV n =O (n –5/2).
I I V n IV n I . . IV n I . I. IV n =O(n –5/2 )
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We study the bifurcations of families of double and quadruple period orbits in a simple Hamiltonian system of three degrees of freedom. The bifurcations are either simple or double, depending on whether a stability curve crosses or is tangent to the axis b=–2. We have also generation of a new family whenever a given family has a maximum or minimum or .The double period families bifurcate from simple families of periodic orbits. We construct existence diagrams to show where any given family exists in the control space (, ) and where it is stable (S), simply unstable (U), doubly unstable (DU), or complex unstable (), We construct also stability diagrams that give the stability parameters b1 and b2 as functions of (for constant ), or of (for constant ).The quadruple period orbits are generated either from double period orbits, or directly from simple period orbits (at double bifurcations). We derive several rules about the various types of bifurcations. The most important phenomenon is the collision of bifurcations. At any such collision of bifurcations the interconnections between the various families change and the general character of the dynamical system changes.  相似文献   

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The consequences of a cosmological term varying asS –2 in a spatially isotropic universe with scale factorS and conserved matter tensor are investigated. One finds a perpetually expanding universe with positive and gravitational constantG that increases with time. The hard equation of state 3P>U (U mass-energy density,P scalar pressure) applied to the early universe leads to the expansion lawSt (t cosmic time) which solves the horizon problem with no need of inflation. Also the flatness problem is resolved without inflation. The model does not affect the well known predictions on the cosmic light elements abundance which come from standard big bang cosmology.In the present, matter dominated universe one findsdG/dt=2H/U (H is the Hubble parameter) which is consistent with observations provided <10–57 cm–2. Asymptotically (S) the term equalsGU/2, in agreement with other studies.  相似文献   

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A coronal condensation was observed simultaneously with Fexiv 5303, Fex 6374, Fe xi 7892, and H filtergraphs. The size and shape of the condensation in 5303 are different from those in other filtergrams. H filtergrams taken around the eclipse time show that a small transient prominence exists in close proximity to the condensation core and behaves like a post-flare loop system, though the appearance is quite different and no flare-report exists. A small-scale energetic phenomenon seems to have occurred at the top of magnetic loops.Contributions from the Kwasan and Hida Observatories, University of Kyoto, No. 285.  相似文献   

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An essential part in the mechanics under study is taking into consideration the effect of motions of the Universe objects upon that of an individual one surrounded by them including those infinitely far from it. Only macro-objects of the Universe are meant here.
Zusammenfassung Ein wesentlicher Bestandteil der Mechanik unter unserer Betrachtung ist die Berechnung des Einflusses auf die Bewegung eines individuellen Objektes von Bewegungen der Universum Objekte die es umringen einschließlich jene Objekte, die unendlich entfernt sind. Nur Makroobjekte des Weltalles sind in der Absicht dabei.

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We use the Cerenkov line emission mechanism to give a new explanation of the observed intensity ratios, particularly the L/H ratio, of the emission lines of quasars. We give equations that restrict the choice of the parameter values. The parameters are the characteristic energy of the relativistic electrons, the number density of neutral hydrogen and its relative level populations. With reasonable choice of the parmaeters, we can obtain calculated L/H, H/H, P/H ratios in agreement with observed values. Our estimate for the gas density in the broad line region of quasars is 1015 cm–3, very different from previous estimates. Unlike previous theories, such a high density causes no difficulties with the Cerenkov line emission.  相似文献   

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