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1.
The first data on ecology and trace metal (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb) bioaccumulation by macrozoobenthic organisms in area along the 130°E meridional transect from shallow water near the Lena River’s delta till the 78°N are presented. At the newly discovered methane seeps in the shallow Laptev Sea areas (72 m depth), a higher total abundance and biomass compared with background stations were recorded. In carbonate shells and soft tissues of Bivalvia Portlandia arctica and Astarte borealis, the high concentrations of Mn, Fe, Pb, Ni and Co were detected that varied in dependence from sampling site. In the dominating taxa of brittle stars (Ophiuroidea), there were found no significant differences between majority of trace metal content in organisms inhabiting the seeps area and background ones. An elevated content of some metals was detected in the Asteroidea bodies that may be attributed to its trophic behavior (deposit feeder). 相似文献
2.
E. V. Ruban G. A. Alekseeva A. A. Arkharov E. I. Hagen-Thorn V. D. Galkin I. N. Nikanorova V. V. Novikov V. P. Pakhomov T. Yu. Puzakova 《Astronomy Letters》2006,32(9):604-607
We present the results of our visual and near-infrared spectrophotometric observations for 77 variable stars obtained during 1971–1991 in Chile, Armenia, and Bolivia. The quasi-monochromatic, extraatmospheric fluxes from the stars are given in absolute energy units (W m?2 m?1) at all wavelengths of the spectral range at 2.5-nm intervals. 相似文献
3.
The structure of the assemblages associated with the mussel aggregations of Bathymodiolus azoricus was investigated. The mussel beds were found on the hydrothermal vent fields on the Mid-Atlantic Ridge (the Menez Gwen, Lucky
Strike, and Rainbow areas) at the depths of 850–2400 m. The community structure of the mussel bed assemblages varied between
the studied areas. Large number of species was unique to Menez Gwen mussel beds; the most observed taxa were not specialized
hydrothermal species. All the other, nonunique species were found for the Lucky Strike region. The lowest mussel assemblage
structure evenness was observed in the shallowest area, the Menez Gwen area (850 m depth). We assume that two types of mussel
assemblages—nematode-dominated and copepod-dominated ones—exist in the Lucky Strike field. The assemblages of B. azoricus differ significantly from the assemblages of B. thermophilus inhabiting the Pacific hydrothermal vents. 相似文献
4.
A series of samples of inhabitants of hydrothermal vents were collected during the 12th cruise of R/V Akademik Mstislav Keldysh in Guaymas Basin (the Gulf of California) and the Axial Seamount area (Juan de Fuca Ridge). The concentrations of trace and heavy metals in the tissues of Ridgeia piscesae, Riftia pachyptila, and Paralvinella palmiformis were analyzed. The neutron-activation analysis revealed significantly higher concentrations of uranium in the tissues of Paralvinella palmiformis as compared to the ambient seawater. The possible reasons for such phenomenon are discussed. The data obtained by the neutron-activation method are compared with those obtained by the atomic-absorption method for the same tissues analyzed. 相似文献
5.
The Barrell and Sears and Edlen formulae use the Sellmeier form away from resonances, which gives a “smooth” dependence within
the visible and near-infrared spectra. All known atlases indicate numerous resonances in these regions, which cause local
disturbance of the dispersion curve. Anomalous dispersion may be estimated from an absorption by the Kramer-Kronig ratios.
It gives a change of phase refractive index of air in a range from several ppt to 1 ppb within narrow optical regions, causing
large local dispersions. Computation of the group refractive index with the use of Rayleigh's ratio shows that the influence
of resonance effects may be more than several ppm. For example, the error of the group refractive index for high-precision
EDM using HeNe lasers (633 nm) varies between 0.2 and 0.7 ppm, depending on the laser stability.
Received: 17 July 1996 / Accepted: 27 March 1997 相似文献
6.
Thermal expansion of ZnSiO3 high-pressure clinopyroxene and ilmenite phases was measured in the temperature range 100–620 K by the X-ray powder diffraction
method. Interpolation and extrapolation of experimental data were performed by the procedure based on the Debye-Mie-Gruneisen
theory in the range from 50 to 1,500 K. Temperature dependencies of molar volumes and coefficients of bulk thermal expansion
of ZnSiO3 phases were determined. 相似文献
7.
Macrofaunal assemblages with the prevalence of Bresiliidae shrimp and Mytilidae mussels are abundant in the hydrothermal vents
along the Mid-Atlantic Ridge. The mussels inhabit the zone of diffuse seeps of hydrothermal fluids with temperature abnormalities
up to several degrees. Shrimps inhabit an extreme biotope in the mixed interface between the seawater and the hydrothermal
fluid at a temperature up to 20–30°C. We studied the mussel and shrimp assemblages in three hydrothermal vent fields: the
Rainbow, Broken Spur, and Snake Pit. The species richness of the mussel assemblages in at least two regions (Broken Spur and
Snake Pit) is higher as compared with the shrimps of the same hydrothermal vent fields. The fauna inhibiting the shrimp swarms
lack almost any taxa specific for particular assemblages: almost all the taxa are also present in the mussel beds. The structure
of the shrimp assemblage is less homogeneous as compared with that of the mussel assemblage. The population prevalence of
one taxon (Copepoda) in the shrimp assemblage is most likely connected with the extreme and unstable conditions of the biotope
occupied by the shrimps in the hydrothermal field. The taxonomic similarity between the mussel and shrimp assemblages within
one hydrothermal vent field is higher as compared with the similarity between the mussel (or shrimp) assemblages from different
fields. 相似文献
8.
A. M. Anokhina V. I. Galkin K. V. Mandritskaya T. M. Roganova 《Astrophysics and Space Science》1993,209(1):19-38
A method for calculating average characteristics of Cerenkov light from very high energy (1–100 TeV) air showers is described. Simple approximation of lateral distribution of light is presented which might be useful for experiment as well as for simulations. 相似文献
9.
Anna Belehaki Ivan Kutiev Bodo Reinisch Norbert Jakowski Pencho Marinov Ivan Galkin Chris Mayer Ioanna Tsagouri Themistocles Herekakis 《Acta Geophysica》2010,58(3):432-452
The purpose of this paper is to evaluate the performance of the TSMP-assisted Digisonde (TaD) topside profiling technique.
We present systematic comparisons between electron density profiles and TEC parameters extracted from TaD model with (a) CHAMP-derived TEC parameters, (b) CHAMP reconstructed profiles, (c) ground based GPSderived TEC parameters, and (d) profiles reconstructed from RPI/IMAGE plasmagrams. In all cases, TaD follows the general trend of plasmaspheric
observations derived from the above datasets. Especially during storm cases, TaD shows remarkable agreement with the variations
of the ground based GPS-derived TEC parameters. Overall, the comparison results shows that TaD method can be adopted by EURIPOS to provide the electron density
distribution up to plasmaspheric heights in real-time. 相似文献
10.
Oceanology - During the 39th cruise of RV Professor Logachev, ecological studies of the Russian exploration area in the central part of the Northern Mid-Atlantic Ridge were conducted. New data on... 相似文献