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1.
Geomorphologic map of the 1<Superscript>st</Superscript> Mutnaya River,Southeastern Kamchatka,Russia
Gheorghe Romanescu Sergey Chalov Cristian Constantin Stoleriu Alin Mihu-Pintilie Silvia Eleonora Angileri Yulia Kuznetsova Mariaelena Cama Michael Maerker 《山地科学学报》2017,14(12):2373-2390
The Kamchatka Peninsula–situated in the Pacific “Ring of Fire”–has 29 active and over 400 extinct volcanoes. Since it is situated in the northeastern extremity of Russia, in subarctic climate, the volcanic landforms are overprinted by the 446 glaciers. This research focuses on the 1stMutnaya catchment which drains the southern slopes of two active volcanoes: Avachinsky and Koryaksky. Those volcanoes are a permanent threat for the cities of Petropavlovsk and Elizovo, which are the 2 of 3 cities of the peninsula. Hence, most of the studies carried out in the area dealt with the natural hazards and only few focus on landscape evolution. Thus, the purpose of this study was to elaborate a cartographic approach which integrates classic geomorphology with state of the art GIS and remote sensing techniques. As result, different landforms and related processes have been analysed and included in the first general geomorphologic map of the 1stMutnaya catchment. 相似文献
2.
Meiobenthos in estuary part of ha long bay (gulf of tonkin, south china sea, vietnam) 总被引:1,自引:0,他引:1
Olga Pavlyuk Yulia Trebukhova Nguyen Vu Thanh Nguyen Dinh Tu 《Ocean Science Journal》2008,43(3):153-160
The distribution of the taxonomical composition and the density of meiobenthos depending on some factors of environment has
been studied in bottom sediments of the northern estuary part of Ha Long Bay (Cua Luc estuary). The basic factor of influence
on meiobenthic community structure was the granulometric composition of sediment. The greatest taxonomic diversity is noted
in the silted sands, lowest — in the silty sediments. The density of meiobenthic community was higher in the silty sediments.
Slightly expressed correlation between the density of nematodes and the percentage of silty particles in the sediments is
detected (Spearman rank correlation coefficient was 0.49±0.21, p=0.035). The nematodes were dominant at all stations. In total,
representatives of 66 species of nematodes belonging to 17 families and 52 genera were identified. 相似文献
3.
Yulia A. Chernetenko 《Celestial Mechanics and Dynamical Astronomy》2001,80(3-4):185-194
International programs of observations of selected minor planets have lasted about 50 years and the last one comes to the end in 2000. The main aim of these observational programs consists in obtaining the orientation of the stellar reference frame with respect to the dynamical one using observations of the bright minor planets. The observations are also useful for the orbital improvements of the asteroids themselves. They are available from the author via e-mail at the address .During the above mentioned period more than 23 000 observations of minor planets, referred to different reference star catalogues, have been obtained. The reduction procedure of observations to the PPM star catalogue is described. The orientation parameters are given and discussed. 相似文献
4.
T. I. Gorbaneva T. V. Mishenina L. F. Orlova 《Bulletin of the Crimean Astrophysical Observatory》2013,109(1):38-40
The manganese content was determined in the atmospheres of 50 F, G, and K dwarfs (?1.0 < [Fe/H] < 0.2) that belong to the galactic thick and thin disks. The observation data were obtained with ELODIE and SOPHIE echelle spectrometers with resolutions of R = 42000 and R = 75000, respectively, using the 1.93-meter telescope of the Haute Provence Observatory. The Mn content was determined under the LTE approximation by the synthetic spectrum approach with a detailed consideration of the superfine structure. The behavior of the Mn content with [Fe/H] in the galactic substructures was analyzed. 相似文献
5.
Based on our compiled catalogue of positions, velocities, ages, and abundances of nine chemical elements for 221 classical Cepheids, we analyze the dependences of the relative abundances of α-elements as well as rapid and slow neutron capture elements on metallicity, space velocity components, and Galactocentric distance. We have found that the relative abundances of all elements in Cepheids do not depend on velocity but increase with Galactocentric distance and decrease with increasing metallicity, just as in thin-disk dwarfs and giants. In Cepheids, however, the [α/Fe]-[Fe/H] relation lies below, while the [r/Fe]-[Fe/H] and [s/Fe]-[Fe/H] relations lie above the analogous sequences for dwarfs and giants. We hypothesize that upon reaching a nearly solar metallicity in the interstellar medium of the thin disk, the most massive stars ceased to explode as type II supernovae, which mostly enriched the interstellar medium with α-elements. As a result, an underabundance of α-elements and a slight overabundance of r-process elements, which are ejected into the interstellar medium by less massive (8–10 M ⊙) type II supernovae, were formed in the next generations of stars. The overabundance of s-process elements in Cepheids can be explained by the fact that some of the s-elements were produced in the weak s-process in the interiors of massive stars, which may be able to eject the upper parts of their envelopes even without any explosion like asymptotic giant branch stars. And since such massive stars, exploding as type II supernovae, also enriched the interstellar medium with a considerable amount of iron atoms, the [s/Fe] ratios (along with [r/Fe]) in the next generations of stars must be higher in their absence. 相似文献
6.
The abundances of 19 chemical elements in the atmospheres of five stars belonging to three globular clusters have been determined by applying the model-atmospheremethod to 430.0–790.0 nm spectra obtained with the échelle spectrometer of the 6-m telescope of the Special Astrophysical Observatory. The abundances of silicon, calcium, iron-peak elements, copper, zinc, and neutron-capture elements follow the abundance patterns for halo stars. The abundance of sodium in M 10 giants provides evidence that different mixing mechanisms operate in halo and cluster stars or that light elements are enriched in different ways in the pre-stellar matter from which some globular clusters and halo stars were formed. 相似文献
7.
Devin L. SCHRADER Dante S. LAURETTA Harold C. CONNOLLY jr. Yulia S. GOREVA Dolores H. HILL Ken J. DOMANIK Eve L. BERGER Hexiong YANG Robert T. DOWNS 《Meteoritics & planetary science》2010,45(5):743-758
Abstract– Sacramento Wash 005 (SaW) 005, Meteorite Hills 00428 (MET) 00428, and Mount Howe 88403 (HOW) 88403 are S‐rich Fe,Ni‐rich metal meteorites with fine metal structures and homogeneous troilite. We compare them with the H‐metal meteorite, Lewis Cliff 88432. Phase diagram analyses suggest that SaW 005, MET 00428, and HOW 88403 were liquids at temperatures above 1350 °C. Tridymite in HOW 88403 constrains formation to a high‐temperature and low‐pressure environment. The morphology of their metal‐troilite structures may suggest that MET 00428 cooled the slowest, SaW 005 cooled faster, and HOW 88403 cooled the quickest. SaW 005 and MET 00428 contain H‐chondrite like silicates, and SaW 005 contains a chondrule‐bearing inclusion that is texturally and compositionally similar to H4 chondrites. The compositional and morphological similarities of SaW 005 and MET 00428 suggest that they are likely the result of impact processing on the H‐chondrite parent body. SaW 005 and MET 00428 are the first recognized iron‐ and sulfide‐rich meteorites, which formed by impact on the H‐chondrite parent body, which are distinct from the IIE‐iron meteorite group. The morphological and chemical differences of HOW 88403 suggest that it is not from the H‐chondrite body, although it likely formed during an impact on a chondritic parent body. 相似文献
8.
The ultramafic rocks of the Kan block, East Sayan, are confined mainly to the Idar greenstone belt. In terms of formational
affiliation, they are subdivided into two groups: magmatic (Kingash Complex) and residual (Idar Complex) ones. The magmatic
ultramafic rocks compose hypabyssal and subvolcanic bodies, which are represented by rocks of dunite-wehrlite-picrite association
with cumulate textures. Uninterrupted chemical variations of the magmatic ultramafic rocks indicate subsequent magmatic differentiation
of parental picritic melt in the intermediate deep-seated chambers and emplacement of its derivatives in the crystallization
site. Differentiation leads to proportional increase of all rare-earth and other incompatible elements. The residual ultramafics
occur as boudined dunite-harzburgite bodies showing metamorphic granoblastic textures. They have more homogenous chemical
composition close to those of ophiolite complexes, which represent strongly depleted mantle rocks brought to the upper lithospheric
levels via deep-seated thrusts. Residual ultramafics differ from magmatic rocks in notably lower contents of some trace and
rare earth elements. 相似文献
9.
For the first time, the structure of the meiobenthos community and marine nematodes in particular was investigated in the
different intertidal zones of Jeju Island (South Sea of Korea). A relationship was found between the density of meiobenthic
communities and the type of the bottom sediment. In addition, in the silty sediments, nematodes were dominant, while in the
sandy sediments harpacticoids and ostracods were dominant groups. Sixty eight species belonging to 60 genera and 19 families
of nematodes were found in the whole area. Four different nematode taxocenosis were distinguished using a cluster analysis.
Dominant feeding groups were omnivores (2B) and epistratum-feeders (2A). The highest number of non-selective deposit-feeders
(1B) was detected in the lagoon with the bottom silty sediments. 相似文献
10.
T. V. Mishenina T. I. Gorbaneva N. Yu. Basak C. Soubiran V. V. Kovtyukh 《Astronomy Reports》2011,55(8):689-703
We have determined abundances of copper, zinc, sodium, and aluminum in the atmospheres of 172 F, G, and K dwarf stars (−1.0
< [Fe/H] < 0.3) belonging to the Galaxy’s thin and thick disks and to the Hercules moving group. Our observations were performed
with the ELODIE échelle spectrometer on the 1.93-m telescope of the Haute Provence Observatory, with a resolving power of
R = 42 000 and signal-to-noise ratio S/N > 100. The Na, Al, Cu, and Zn abundances were derived in an LTE approximation; the synthetic spectrum for the copper lines
was calculated taking into account super-fine structure of the lines. We analyzed the abundances of these elements as a function
of metallicity [Fe/H] for stars of the thin and thick disks of the Galaxy and the Hercules moving group. The Cu abundances
and their trends with metallicity are essentially the same in the three studied sub-structures. The mean Al and Zn abundances
for stars of the thin and thick disks differ significantly. 相似文献