The Ni–Antimonide Mineral Assemblage: A Product of Recrystallization of Sn–Pb–Zn Ores of the Yuzhnoe Deposit,Sikhote-Alin,Russia     

Ratkin  V. V.  Simanenko  L. F.  Gonevchuk  V. G.  Eliseeva  O. A. 《Doklady Earth Sciences》2020,492(1):317-319

Doklady Earth Sciences - A mineral assemblage with nisbite NiSb2 and breithauptite NiSb unique for a Mesozoic (Sn)–Pb–Zn vein deposit is found during mineralogical–geochemical...  相似文献   

Organized Roll Circulation and Transport of Mineral Aerosols in the Atmospheric Boundary Layer     

Vazaeva  N. V.  Chkhetiani  O. G.  Maksimenkov  L. O. 《Izvestiya Atmospheric and Oceanic Physics》2019,55(2):152-166

Izvestiya, Atmospheric and Oceanic Physics - An investigation into mesoscale roll circulation and its transport characteristics in the atmospheric boundary layer (ABL) is carried out. The case...  相似文献   

Phytoplankton Community Structure in the Polar Front of the Eastern Barents Sea at the End of the Growth Season     

V. M. Sergeeva  L. S. Zhitina  S. A. Mosharov  A. A. Nedospasov  A. A. Polukhin 《Oceanology》2018,58(5):700-709

Phytoplankton community and its distribution were investigated in the south part of the Polar Front in the eastern Barents Sea in October 2014. Analysis of the spatial differences in the phytoplankton structure was performed in connection with changes of the temperature, salinity and biogenic regime. At the end of the growing season in the phytoplankton community was dominated by destruction processes and the concentration of nutrients in the upper mixed layer was higher than the limiting level. Coccolithophores (Emiliania huxleyi and Discosphaera cf. tubifer) dominanted over investigated area. The maximum values of abundance and biomass of coccolithophores reached 90.4 mln.cell/m³ and 30.8 mgC/m³, drawing up 82% of the total number and 93% of the total biomass of phytoplankton. Influence of transformed the waters of Atlantic origin was observed in the western part of the investigated area. The number of species in the phytoplankton community here was 1.5–2 times lower than in the eastern part of the occupied mostly by Barents Sea water. In the eastern part of the presence of large dinoflagellates Neoceratium spp. (Ceratium spp.) and Dinophysis spp., lower values of chlorophyll a concentration, a higher proportion of pheophytin in the amount of pigment chlorophyll + pheophytin, the high content of ammonia in the upper mixed layer showed that in this area the phytoplankton was at a later seasonal succession stage than the western part.  相似文献   

On yoderite: Using calculated phase equilibria to investigate its rarity in the geological record of whiteschists          下载免费PDF全文

Brandon L. Alessio  David E. Kelsey 《Journal of Metamorphic Geology》2018,36(3):297-314

A new activity–composition model is presented for green (Mn³⁺‐absent) yoderite for use in the latest internally consistent thermodynamic data set used by THERMOCALC, for calculations primarily in MgO–Al₂O₃–SiO₂–H₂O–O system, where O is a proxy for Fe₂O₃. P–T grids calculated with our model in the MASH and MASHO system feature invariant points and univariant reaction bundles that are consistent with existing experimental results. Using this new model, we have explored the stability of yoderite in whiteschists, a rare type of high‐pressure rock that conforms closely to the MASHO system. Using a series of calculated models in which composition varies, it is shown that yoderite stability is a function of bulk‐rock SiO₂, MgO and Al₂O₃, where the most important component for stabilizing yoderite is a function of pressure and temperature. The rarity of yoderite in naturally occurring whiteschists is largely related to these compositional factors, with most whiteschists having rock compositions that are too SiO₂‐rich and Al₂O₃‐poor to allow yoderite formation. However, in addition to compositional factors, the calculated P–T stability field of yoderite occurs over thermal gradients that are generally too high to occur in modern‐style subduction zones. As nearly all known whiteschist occurrences are Phanerozoic in age, the near‐complete absence of yoderite in late Neoproterozoic–Phanerozoic whiteschists may be at least partially due to modern subduction systems failing to produce the hotter thermal gradients needed to stabilize yoderite. The provision of this new a–x model for green yoderite allows for more rigorous P–T–X investigations of all whiteschists.  相似文献   

Light Chemical Elements in Stars: Mysteries and Unsolved Problems     

L. S. Lyubimkov 《Astrophysics》2018,61(2):262-285

  相似文献   

Astrometric Observations of the Galilean Moons of Jupiter at the Pulkovo Normal Astrograph in 2016−2017     

N. V. Narizhnaya  M. Yu. Khovrichev  A. A. Apetyan  D. A. Bikulova  A. P. Ershova  I. A. Balyaev  A. M. Kulikova  K. I. Os’kina  L. A. Maksimova 《Solar System Research》2018,52(4):312-319

We present the results of observations of the Galilean moons of Jupiter carried out at the Normal Astrograph of the Pulkovo Observatory in 2016?2017. We obtained 761 positions of the Galilean moons of Jupiter in the system of the Gaia DR1 catalog (ICRF, J2000.0) and 854 differential coordinates of the satellites relative to each other. The mean errors in the satellites’ normal places and the corresponding root-mean-square deviations are ε_α = 0.0020′′, ε_δ = 0.0027′′, σ_α = 0.0546′′, and σ_δ = 0.0757′′. The equatorial coordinates of the moons are compared to the motion theories of planets and satellites. On average, the (O–C) residuals in the both coordinates relative to the motion theories are less than 0.031′′. The best agreement with observations is achieved by a combination of the EPM2015 and V. Lainey-V.2.0|V1.1 motion theories, which yields the average (O–C) residuals of approximately 0.02″. Peculiarities in the behavior of the (O–C) residuals and error values in Ganymede have been noticed.  相似文献   

Generation of the Stressed State of the Lithosphere of the Earth and Mars Caused by the Reorientation of Their Figures     

A.?L.?TserklevychEmail author  O.?S.?Zayats  Ye.?O.?Shylo  O.?M.?Shylo 《Kinematics and Physics of Celestial Bodies》2018,34(1):19-36

The computer simulation of the reorientation of the Earth and Mars lithosphere figure has been performed, which due to the dynamic redistribution of masses, allowed to reveal certain regularities of the structure-forming processes. It has been shown that the shape of the lithosphere surface has a different orientation relatively to the geoids’ (aroids) figure. This causes redistribution of masses leading to a strained state of the lithosphere as a result of endogenous and gravitational-rotational forces action in the evolutionary processes of planet’s self-development. The solution of this problem is considered on the example of lithosphere surface heights approximation by a biaxial ellipsoid with seven parameters. The acting horizontal forces in the upper shell of the planet has been calculated, introducing the concept of “evolutionary deviation of the plumb” and assuming that the tangential forces are proportional to the angle, which is defined as the angle between the direction of the plumb line in the past geological epoch and the plumb line direction at a given point. The calculated fields of tangential force vectors show good consistency with the direction of space-time displacement of Earth’s continents and tectonic plates and consistent with the results of the horizontal movements of GNSS stations. This is quite convincing evidence that under the long-term action of vortex rotationalgravitational forces, the lithospheres masses acquire the properties of creep. All this leads to the fact that interacting blocks and plates within the vortex rotational-gravitational model can be interconnected to elastic fields that creates a single planetary geodynamic field that forms the evolutionary state of the geo-environment.  相似文献   

Baikal Electromagnetic Experiment     

Korotaev  S. M.  Budnev  N. M.  Serdyuk  V. O.  Orekhova  D. A.  Kruglyakov  M. S.  Kiktenko  E. O.  Mirgazov  R. R.  Zurbanov  V. L.  Gorokhov  Ju. V.  Ryabov  E. V. 《Izvestiya Atmospheric and Oceanic Physics》2018,54(11):1569-1594

Izvestiya, Atmospheric and Oceanic Physics - The vertical component of the electric field Ez in the hydrosphere is not contaminated by the telluric component and therefore can effectively be used...  相似文献   

On the Trajectories of Asteroid Encounters with the Earth for 2015 RN35 and Apophis     

N.?A.?Petrov  A.?A.?Vasil’ev  G.?A.?Kuteeva  L.?L.?SokolovEmail author 《Solar System Research》2018,52(4):326-337

A great number of probable encounters of asteroid 2015 RN35 with the Earth have been found; many of them were unknown earlier. The main characteristics and properties of the corresponding trajectories have been obtained. Probable impacts of the asteroid Apophis with the Earth are also discussed. The results suggest that the multitudes of potential impacts of hazardous asteroids with the Earth can be and must be analyzed in more detail. Such an analysis is required to plan and implement the measures on preventing the asteroid impact hazard.  相似文献   

The spawning and early life-history of a New Zealand endemic amphidromous eleotrid,bluegill bully (Gobiomorphus hubbsi)     

Matt G. Jarvis  Hannah A. Harland  Manna L. Warburton  Gerard P. Closs 《新西兰海洋与淡水研究杂志》2018,52(1):55-68

The larval stage of fishes is critical in determining their dispersal, survival and recruitment, but little is known of the larval behaviours and tolerances of amphidromous fishes, particularly in New Zealand. We report the results of a series of observational and experimental studies on bluegill bully (Gobiomorphus hubbsi), including spawning sites and behaviours, larval characteristics at hatch, phototactic responses of larvae, and larval survival at different salinity levels. Spawning primarily occurred in the lower reaches of the river, and larvae from different nests exhibited marked differences in, and trade-offs between, larval characteristics at hatch, potentially affecting larval success. Larvae were positively phototactic to intense light, an unexpected result based on diel drift patterns and international research. Finally, larvae exhibited markedly higher survival rates when reared at intermediate salinities compared to freshwater or seawater, suggesting estuaries may play an important role as nursery grounds for bluegill bully and other amphidromous fish.  相似文献