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231.
J. Sýkora 《Solar physics》1992,140(2):379-392
The long-term distribution of the Green Corona Low Brightness Regions (GCLBR) on the solar surface is investigated. The frequency curves of the GCLBR follow the solar cycle, but are displaced considerably relative to the curve of the sunspot number cycle. The observed displacement increases with the size of the GCLBR and reaches up to 4–5 years for the largest regions. It is, however, interesting that the displacement in the equatorial zone is opposite to that in the higher-latitude zones.An older idea on the physical affinity between GCLBR and coronal holes led us to study the frequency of GCLBR and the properties of High-Speed Plasma Streams (HSPS) in the solar wind. Maximum velocity and duration of the coronal-hole-related HSPS seem to be well correlated with the number and size of GCLBR located in the N 60-N 20 and S 20-S 60 latitudinal zones. This is particularly evident at the end of the solar cycle.Geophysical Kp and aa indices are used to demonstrate a possible genetic dependence of geoactivity on the size, position on the Sun's surface and frequency of the GCLBR. In this sense, the most pronounced period is 1973–1976.
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232.
We analyze the complex pattern of anticorrelation between the degree of polarization p in the green λ530.3-nm line and its intensity I λ, which was revealed by coronal observations during the total solar eclipse of July 11, 1991. For coronal points located at approximately the same distance from the disk center, the anticorrelation diagram breaks up into two branches with a zone of avoidance between them. High-latitude streamers form the upper branch, while the lower branch belongs to active equatorial regions. The arrangement of large-scale coronal structures in the p-logI λ diagram is considered for a distance of 1.2R ⊙. The change in anticorrelation diagram with distance is analyzed in detail for the giant high-latitude coronal streamers observed on July 11, 1991. Our results contain important information about the scattering of photospheric radiation at line frequencies in the presence of a coronal magnetic field. 相似文献
233.
On the basis of a review of data on the effective cross-sections of particle interactions, computations of the effective electron-neutron interaction, of the cross-section values for H, H2 and He were carried out in the range 0.8 1.7 and 2.5 logP
g 6.5. The mean cross-sections for the solar mixture used by Zwaan were computed (see Table II). Using these results, the values of the electric conductivity and of its anisotropy coefficient were computed (see Tables VII and VIII), as well as other auxiliary quantities. The conductivity values obtained are in the range from 5 × 109 to 5 × 1012 CGSE units for the assumed physical conditions.On leave from the Astronomical Institute of the Czechoslovak Academy of Sciences, Ondejov, Czechoslovakia. 相似文献
234.
235.
Daniela Plachá Helena Raclavská Dalibor Matýsek Mark H Rümmeli 《Geochemical transactions》2009,10(1):12-21
The polycyclic aromatic hydrocarbon (PAH) contamination of urban, agricultural and forest soil samples was investigated from
samples obtained in the surroundings of Valasske Mezirici. Valasske Mezirici is a town located in the north-east mountainous
part of the Czech Republic, where a coal tar refinery is situated. 16 PAHs listed in the US EPA were investigated. Organic
oxidizable carbon was also observed in the forest soils. The PAH concentrations ranged from 0.86-10.84 (with one anomalous
value of 35.14) and 7.66-79.39 mg/kg dm in the urban/agricultural and forest soils, respectively. While the PAH levels in
the urban/agricultural soils are within the range typically found in industrialized areas, the forest soils showed elevated
PAH concentrations compared to other forest soils in Western and Northern Europe. The PAH concentrations and their molecular
distribution ratios were studied as functions of the sample location and the meteorological history. The soils from localities
at higher altitudes above sea level have the highest PAH concentrations, and the PAH concentrations decrease with increasing
distance from the town. 相似文献
236.
237.
Jaromír Janský Vladimír Plicka Helene Lyon-Caen Oldřich Novotný 《Journal of Seismology》2007,11(2):199-204
We determine the velocities in an upper crustal model, composed of three homogeneous layers, for one subregion of the western
part of the Gulf of Corinth, NE of the town of Aigion, Greece. We have used local events that occurred there in the year 2001
and were recorded by the Corinth Rift Laboratory Network. Weighted P and S arrival time residuals are minimized using the Neighbourhood Algorithm of Sambridge (1999), combined with the grid search
for source locations. The resolution of the inversion is tested by delete-one jackknifing. The model obtained is compared
with some other models derived or applied to the subregion. A fast velocity increase between depths of 5 and 7 km is confirmed
as the major structural element. 相似文献
238.
Cyclic variations of the mean semi-annual intensities I
of the coronal green line 530.3 nm are compared with the mean semi-annual variations of the Wolf numbers W during the period of 1943–1999 (activity cycles 18–23). The values of I
in the equatorial zone proved to correlate much better with the Wolf numbers in a following cycle than in a given one (the correlation coefficient r is 0.86 and 0.755, respectively). Such increase of the correlation coefficient with a shift by one cycle differs in different phases of the cycle, being the largest at the ascending branch. The regularities revealed make it possible to predict the behaviour of W in the following cycle on the basis of intensities of the coronal green line in the preceding cycle. We predict the maximum semi-annual W in cycle 23 to be 110–122 and the epoch of minimum between cycles 23 and 24 to take place at 2006–2007. A slow increase of I
in the current cycle 23 permits us to forecast a low-Wolf-number cycle 24 with the maximum W50 at 2010–2011. A scheme is proposed on the permanent transformation of the coronal magnetic fields of different scales explaining the found phenomenon. 相似文献
239.
The scientific and operational aims of the Czech-made Hard X-Ray Spectrometer (HXRS) launched onboard the U.S. Department
of Energy Multispectral Thermal Imager satellite (MTI), on 12 March 2000 are discussed. The principal operating characteristics
of the instrument such as the temporal resolution, energy band selection, spectral sensitivity, and the in-flight calibration
procedure are described as well as the technical details of the spectrometer including detectors, shielding (against charged
particles) and electronic design. The MTI host satellite and its orbit are briefly described. Recent observations by the 3 GHz
Ondřejov radiometer are compared with HXRS data to demonstrate one example of the HXRS data utilization: the temporal relation
between hard X-rays and radio emission. These results show relatively long time delays (2–14 s) of the GHz broadband radio
pulses relative to the hard X-ray emission peaks. Access to the HXRS data base via the Internet is provided. 相似文献
240.
M. Šidlichovský 《Celestial Mechanics and Dynamical Astronomy》2005,93(1-4):167-185
An adiabatic approximation for the non-planar, circular, restricted 3BP is presented for the external resonance 4/7. It can
be used as a model for resonant Kuiper belt objects. The Hamiltonian is truncated at the fourth order in eccentricities and
inclinations. After averaging, we have a system of two degrees of freedom with two frequencies. Numerical calculations show
that the ratio of these frequencies is ~102. Having introduced suitable canonical variables, we used the adiabatic approach introduced by Wisdom in a different context.
We left slow variables frozen and after solving the pendulum problem for fast variables, we used the averaged effect of fast
variables on slow variables. In this way we obtained the guiding trajectories for slow variables as contour lines of adiabatic
invariant. We discuss the existence of a chaotic region which is formed by trajectories crossing a critical curve which corresponds
to the separatrix of fast pendulum motion, where the assumption of sharp division between fast and slow frequencies is not
correct and the adiabatic theory fails. The model works well for e ~ 0.1 and can be used for finding the chaotic regions, but for e~ 0.17 it becomes unsatisfactory due to truncation and bad convergence of the Laplace expansion. Qualitatively it can, however,
help us to understand how the protective mechanism works as the interplay of mean motion and Kozai–Lidov resonance. 相似文献