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991.
Preliminary results of polarization measurements at three solar flares of July 5 and 6, 1974, are given. The measurements were performed at h 15 keV with Thomson-scattering polarimeter on the Intercosmos 11 satellite.At the decay phase of the flare on July 5 we obtained P = 3.4–5.0%, which did not exclude some contribution from non-thermal processes. At the flares of July 6 we found P =1.0–1.9% and P = 0.1–2.0%, respectively: neither value exceeds the level of statistical fluctuations.Presented at XVIII COSPAR Meeting (VARNA, May–June 1975), contribution III.B.2.9. 相似文献
992.
Slitless spectrograms obtained during the eclipse of 10 June 1972 have been analyzed to determine the height distribution of the D3 He line intensity.For undisturbed regions the maximum of D3 line intensity is confirmed to exist at about 1700km above the limb. Besides the above mentioned maximum, in plages a considerable intensity may be observed at low heights (h < 1000 km).An analysis of these observations for h > 1000 km has been carried out within the low temperature mechanism of triplet helium emission taking into account the helium ionization by XUV radiation. The density dependence of the 23
S level population at different XUV flux values has been calculated. Our observations give N
e 2 × 1010 cm–3 in the chromosphere at h = 2000 km. The probable coincidence of the H and He emission small filaments in the middle chromosphere is discussed. 相似文献
993.
Vertical small scale velocities deduced from highly resolved spectra in the center of the solar disk, obtained with a RCA image intensifier tube, are discussed. As a main result we find that the velocities of small elements (< 2) are remarkably larger in active regions around sunspots than in the quiet Sun. In both cases the velocities decrease with height in the solar atmosphere (Figure 2).Mitteilungen aus dem Fraunhofer-Institut Nr. 145. 相似文献
994.
We report new results obtained from high precision computer controlled tracings of ca. 400 bright Ca+-mottles made during summer 1975 in continuation of our 1974 program (Schröter and Wöhl, 1975). In particular, we looked in 1975 for the existence of a giant circulation pattern in the equatorial zone. We find for the differential rotation: = 13.93 – 2.90 sin2
B (deg/day, sidereal) when combining the new measurements with those obtained in 1974. Observations from 26th April until June 19th give strong evidence that at that time four giant circulation cells, crossing the solar equator, (i.e. a nonaxisymmetric velocity field pattern with respect to the solar equator) did exist. This yields two more rapid and two slower rotating sectors with v = ±80 m s–1. These giant cells transport angular momentum towards the equator. 相似文献
995.
A new multivariate statistical technique have been developed for detection of populations groupings in data arrays. General characteristics of the method are described. Results obtained analyzing lunar rocks and glasses are discussed. Lunar rocks lie in a genetically related sequence: pyroxenitic mantle materials produce mare type basalts; anorthositic rocks are the most distant members of the differentiation; noritic, hi-Ti and high KREEP basalts materials appear to be intermediate products. Lunar glasses parallel the overall behaviour of rocks, with some peculiar local characteristics. Granitic materials are present only as glasses, suggesting an origin as residuals. Links between several identified classes are discussed in terms of the evolution of the lunar crust. 相似文献
996.
997.
998.
I. Lerche 《Astrophysics and Space Science》1976,43(1):91-96
We demonstrate that the so-called force balance point, due to either magnetic fields (then known more specifically as the Alfvén point) or to co-rotation (Roche point), together with the concepts of flux and mass conservation, allows one to place interesting limits on both the size and angular velocity of astrophysical objects emitting by mass accretion. We give three numerical examples, which would seem to be of some astrophysical interest. 相似文献
999.
I. F. Mirabel 《Astrophysics and Space Science》1976,39(2):415-417
A search for neutral hydrogen in the velocity range –300>V>–1000 km s–1 has been made in the zone around the galactic nucleus. Observations of 100 points reveal no neutral hydrogen at such high velocities, with brightness temperatures exceeding 0.25 K in the latitude range |b|<1°, and 0.20 K for |b|1°. 相似文献
1000.
W. W. Duley 《Astrophysics and Space Science》1976,45(2):261-267
Temperature fluctuations induced in very small (r10–3 ) interstellar grains by the absorption of photons from the ultra-violet radiation field or by energy released on molecule formation are shown to lead to significant gas heating due to thermal desorption of condensed atoms or molecules. For clouds with N(H)=1–10×1020 cm–2, heating rates due to this process are comparable to direct heating by cosmic rays or grain photoelectrons. 相似文献