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941.
Khamitov I. M. Bikmaev I. F. Burenin R. A. Glushkov M. V. Melnikov S. S. Lyapin A. R. 《Astronomy Letters》2020,46(1):1-11
Astronomy Letters - An example of simultaneous spectroscopic redshift measurements for a large number of galaxies in a cluster by multiobject spectroscopy with the medium- and low-resolution TFOSC... 相似文献
942.
Astronomy Letters - Based on an analysis of the dynamic spectra for solar flares in the meter wavelength range obtained with the ground-based Radio Solar Telescope Network, we consider the... 相似文献
943.
Ivanova J. N. Vyhristenko R. I. Vikentyev I. V. 《Izvestiya Atmospheric and Oceanic Physics》2020,56(12):1537-1545
Izvestiya, Atmospheric and Oceanic Physics - The central part of the Malouralsky volcanic–plutonic belt, which includes the Manyukuyu–Vorchatinsky ore cluster, is analyzed using... 相似文献
944.
945.
The continuity equation of CAVALIERE et al. (1971) generalized to age-dependent luminosity evolution (BOLLER and LIEBSCHER 1989) is used to calculate quasar luminosity functions. For some combinations of source functions S(L, t) and evolutionary pathes M(L) we discuss the resulting N — m relations and the amount of the X-ray background and compare them with actual results of observation. We can exclude certain models, (S(L, t), M(L)). We cannot yet decide what the actual source function and the actual evolutionary path are. 相似文献
946.
We consider current problems connected with the evolution of central dominant (cD) galaxies in clusters. In the second part of this series, internal properties of the cD galaxy — in particular its radio structure — are related to the appropriate ones of the cluster. The observations point to an earlier jet ejection along the major axis of the galaxy and a following change of the jet axis. From the existence of “hot-spot” like regions in different directions it is suggested that the radio engine would have to be intermittent with a relatively short period. Alternatively to the intermittent ejection scenario, the radio morphology of 4C 26.42 can be explained in the frame of the “standard” beam or jet model. The radio structure of 4C 26.42 being an inversion-symmetric configuration, which is probably due to galactic cannibalism, could be interpreted as a transition at the inner hot spots (at about 1 kpc) from supersonic, stable Fanaroff-Riley type II jets to subsonic, unstable FR I type structures (“plumes”). A quantitative investigation of the two scenarios for jet interaction with the surroudning interstellar/intercluster medium in 4C 26.42 gives parameter values in reasonable agreement with the ones discussed in the literature for related objects. 相似文献
947.
948.
Kenneth R. Young 《Geographical review》2019,109(2):258-264
949.
Understanding what drives farmers’ voluntary adoption of nutrient and soil best management practices has important consequences for many environmental outcomes including water quality. We build on research revealing the need for simultaneous use of multiple nitrogen best management practices to achieve water quality improvement goals. Using social, economic and attitudinal variables we predict the use of multiple nitrogen best management practices at three time points: current use (2013), past use (before 2013), and likelihood of use on their largest field in the next three years. Our empirical analysis uses structural equation modeling with latent variables and 2014 farmer survey data from three Midwestern US states. Most farmers in our sample used at least one of the six best management practices. Our results reveal that farmers’ attitudes, use of information sources, and conservation program participation affect the number of nitrogen best management practices concurrently in use at multiple time points. 相似文献
950.
M. R. Voelzke 《Meteoritics & planetary science》2019,54(4):938-945
This work is based on a systematic analysis of images of comet 1P/Halley collected during its penultimate and ultimate approaches, i.e., in 1910 and 1986. This research has identified, characterized, classified, and compared tail structures of comet 1P/Halley, namely disconnection events (DEs), wavy structures, and solitons. The images of the comet during its 1910 passage, as illustrated in the Atlas of Comet Halley 1910 II (Donn et al. 1986), were compared with those of its approach in 1986 as illustrated in The International Halley Watch Atlas of Large‐Scale Phenomena (Brandt et al. 1992). Two onsets of DEs were discovered after the perihelion passage in 1910 with an average value of the corrected cometocentric velocity (Vc) of 57 ± 15 km s?1. Ten onsets of DEs were discovered after the perihelion passage in 1986 with an average Vc equal to 130 ± 37 km s?1. The mean value of the corrected wavelength λc of wavy structures in 1910 is equal to 1.7 ± 0.1 × 106 km, as compared to 2.2 ± 0.2 × 106 km in 1986. The mean value of the amplitude A of the wave in 1910 is equal to 1.4 ± 0.1 × 105 km and 2.8 ± 0.5 × 105 km in 1986. The goals of this research were to report the results obtained from the analysis of the P/Halley's images from 1910 and 1986, to provide empirical data for comparison, and to form the input for future physical/theoretical work. 相似文献