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排序方式： 共有70条查询结果，搜索用时 531 毫秒
11.
Geomagnetism and Aeronomy - This paper presents observational series of the spectral solar corona obtained with the Small Lyot Coronagraph deployed in 1948 at the Mountain Astronomical Station of... 相似文献
12.
Data are presented on a partial solar eclipse, which occurred on January 4, 2011, and was observed with RT-3 (?? = 4.9 cm) and RT-2 (?? = 3.2 cm) radio telescopes at the Mountain Astronomical Station, Central Astronomical Observatory, Russian Academy of Sciences (MAS CAO RAS). The radioemission flux in two channels was registered using digital methods with a time resolution of 0.5 s. Comparisons were performed with observations in the optical, UV, and X-ray ranges. The following local sources of increased radioemission on the solar disk have been identified: sunspot groups 1 (NOAA 1142) and 126 (NOAA 1141), unipolar sunspot 127 (NOAA 1140), facula areas, and polar and midlatitude coronal holes. It has been indicated that the brightness of a unipolar sunspot (for ?? = 4.9 cm, I rel = 29.5; for ?? = 3.2 cm, I rel = 10.1) and two sunspot groups (for ?? = 4.9 cm, I rel = 10.1 and 14.2; for ?? = 3.2 cm, I rel = 5.1 and 6.2) is maximal. The radioemission flux of all found coronal holes is decreased, and the decrease is more contrasting in the 4.9-cm range as compared to such a decrease in the 3.2-cm range. Radio maps of the Sun and changes in the radioemission flux of undisturbed solar regions from the center to the limb for ?? = 4.9 and 3.2 cm have been constructed based on the eclipse data. 相似文献
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A 1.2 m snow pit was recovered on July 29th, 2009 from the Bogda Glacier, eastern Tianshan (天山). The sample site temperature of -9.6 ℃ indicates that the unique glaciochemical re-cord was well preserved and suitable for the reconstruction of air pollution levels in this previously un-explored region. Samples were analyzed for major ions (Na+, K+, Ca2+, Mg2+, NH4+, Cl-, SO42-, NO3-, HCOO-, and CH3COO-). NO3- and SO42- were characterized by significant high levels of pollution con-centration. Most air masses ... 相似文献
15.
M. J. Chebotina E. V. Polyakov V. P. Guseva N. A. Khlebnikov V. T. Surikov 《Doklady Earth Sciences》2011,439(2):1138-1140
This paper provides for the first time comparative assessment of the contents of 70 chemical elements occurring in the aquatic
environment in water, phytoplankton, and zooplankton. The assessment was made using modern highly sensitive methods. The studies
were performed at Beloyarskoe Reservoir, a manmade freshwater lake situated in the Middle Urals that has been studied in detail.
The chemical elements were ranked in groups differing in the accumulation coefficient (AC) values for the phyto- and zooplankton.
The comparison revealed that for the vast majority of chemical elements, the AC values were higher in zooplankton (53, or
76%) than in phytoplankton (17, or 24%). The average AC values for zooplankton (∼740 000) exceeded that for phytoplankton
(∼68 000) by more than 10 times. It was found that some elements had very high AC values in zooplankton compared to phytoplankton.
For instance for Nb, the ratio ACzoo/ACphyto was 1 200 000; for B, Ta, Sn, Lu, U, 300 000–500 000; for Sb and Y, 100 000–130 000; for La and Nd, 80 000–85 000; for Mo,
Cd, Pr, Gd, Dy, Sc, Se, Bi, 20 000–30 000; and for Pd, Hf, Sm, Sb, Er, As, 10 000–20 000. It is concluded that zooplankton
is sometimes more suitable for the biogeochemical indication of the pollution of natural water bodies, because the AC values
for most elements are much higher in zooplankton than in phytoplankton and the total plankton. Considering the high assimilability
of microelements and radionuclides, the plankton may serve not only as an indication but also as the mean of regulated purification
of waterbodies from these elements. 相似文献
16.
E. I. Gerasimova I. V. Pekov N. N. Kononkova M. F. Vigasina N. V. Chukanov E. V. Guseva 《Moscow University Geology Bulletin》2013,68(1):43-51
Based on microprobe analysis and IR-spectroscopy of a representative collection of magnesium minerals of the humite group (282 samples from 80 various geological-genetic occurrences all over the world), it was shown for the first time that these minerals typically concentrate trace boron (from 0.5 to 4.9 wt % B2O3 in 63 samples). The diagnostic bands of B-O stretching vibrations in IF-spectra of magnesium minerals of the humite group occur within the 1170–1190, 1262–1289, and 1306–1331 cm?1 ranges and are regularly shifted to the low frequencies in a norbergite-chondrodite-humite-clinohumite series. Boron isomorphically replaces silicon in tetrahedra, probably, by Pertsev’s scheme: Si4+ + O2? → B3+ + (F,OH)?. 相似文献
17.
Based on the results of photogeological analysis of the Thetis Regio on Venus, 13 material and 3 structural subunits were mapped and the relative sequence of their formation was determined. Two subunits are represented by impact craters, which were subdivided into relatively older (C1, 7 craters) and younger (C2, 8 craters) ones, according to the presence and clarity of the associated radio-dark halo. Taking into account the data from previous studies, it was established that the age of the first group was older than 1/2T or 1/3T, where T is the average age of the surface of Venus, and the age of the second group was younger than these values. Analyzing the age relationships between these craters and other geological subunits, it was determined that the formation of one of the largest rift zones in this area of Venus occurred later than at 1/3T up to the present time. 相似文献
18.
M. A. Pogodin N. G. Beskrovnaya G. G. Valyavin I. S. Guseva S. E. Pavlovskiy N. Rusomarov O. V. Ezhkova 《Bulletin of the Crimean Astrophysical Observatory》2013,109(1):23-26
We present first results of the photometric and spectroscopic investigation of the B1/B2 Herbig star HD52721 performed in 2009–2010 at three observatories: Mountain Astronomical Station (Kislovodsk)—photometry, CrAO (Crimea, Ukraine)—spectroscopy, Observatory San Pedro Martyr (Ensenada, Mexico)—high-resolution echelle-spectroscopy. We have also used photometric data from the ASAS survey for 2003–2009. Our analysis has shown that a) the object is a close binary system with the orbital period of 1.610 days composed of two components of similar spectral type (B1–B2); b) the system is surrounded by the common disk-like envelope containing azimuthal inhomogeneity rotating with the orbital period of the system. We present preliminary estimates of the system parameters and discuss its possible nature. 相似文献
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