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21.
Kurnosov V. B. Sakharov B. A. Geptner A. R. Konovalov Yu. I. Goncharov E. O. 《Lithology and Mineral Resources》2019,54(3):221-235
Lithology and Mineral Resources - Clay minerals (fraction <0.001 mm) of Upper Pleistocene clayey–sandy–silty sediments recovered by DSDP Holes 481 and 481A in the Northern... 相似文献
22.
Strong Tidal Mixing and Ventilation of Cold Intermediate Water at Kashevarov Bank, Sea of Okhotsk 总被引:1,自引:0,他引:1
Konstantin A. Rogachev Eddy C. Carmack Alexandr S. Salomatin 《Journal of Oceanography》2000,56(4):439-447
Tidal mixing at the Kashevarov Bank, Sea of Okhotsk, has been investigated using observations of bottom pressure and currents. The tides are dominated by the diurnal constituents. The water motion over the Bank is predominantly controlled by strong diurnal tidal currents, which bring cold water on the bank from its source, a cold intermediate layer. The temperature fluctuations are about 1.2°C at the southern edge of the bank. The maximum observed velocity is about 164 cm/s at the top of the bank. A superposition of the original diurnal constituents K1 and O1 reveals a strong fortnightly (Mf) variability of the current speed. Tidal-induced mixing is responsible for ventilation of the cold intermediate layer of the Sea of Okhotsk. Strong tidal mixing creates a well-defined tidally mixed front around the bank. This front acts like a barrier separating well-mixed water on the bank from stratified water on its flanks. There is a residual current of the order of 10 cm/s. 相似文献
23.
Dmytro M. Trots Alexander Kurnosov Leonid Vasylechko Marek Berkowski Tiziana Boffa Ballaran Daniel J. Frost 《Physics and Chemistry of Minerals》2011,38(7):561-567
A single crystal X-ray diffraction study on lithium tetraborate Li2B4O7 (diomignite, space group I41
cd) has been performed under pressure up to 8.3 GPa. No phase transitions were found in the pressure range investigated, and
hence the pressure evolution of the unit-cell volume of the I41
cd structure has been described using a third-order Birch–Murnaghan equation of state (BM-EoS) with the following parameters:
V
0
= 923.21(6) Å3, K
0
= 45.6(6) GPa, and K′ = 7.3(3). A linearized BM-EoS was fitted to the axial compressibilities resulting in the following parameters a
0
= 9.4747(3) Å, K
0a
= 73.3(9) GPa, K′
a
= 5.1(3) and c
0
= 10.2838(4) Å, K
0c
= 24.6(3) GPa, K′
c
= 7.5(2) for the a and c axes, respectively. The elastic anisotropy of Li2B4O7 is very large with the zero-pressure compressibility ratio β
0c
/β
0a
= 3.0(1). The large elastic anisotropy is consistent with the crystal structure: A three-dimensional arrangement of relatively
rigid tetraborate groups [B4O7]2− forms channels occupied by lithium along the polar c–axis, and hence compression along the c axis requires the shrinkage of the lithium channels, whereas compression in the a direction depends mainly on the contraction of the most rigid [B4O7]2− units. Finally, the isothermal bulk modulus obtained in this work is in general agreement with that derived from ultrasonic
(Adachi et al. in Proceedings-IEEE Ultrasonic Symposium, 228–232, 1985; Shorrocks et al. in Proceedings-IEEE Ultrasonic Symposium, 337–340, 1981) and Brillouin scattering measurements (Takagi et al. in Ferroelectrics, 137:337–342, 1992). 相似文献
24.
Alexandr V. Vikulin Tatiana Yu. Tveritinova Alexandr G. Ivanchin 《Acta Geophysica》2013,61(2):245-263
The work presents a review of natural-science representations on the rotary motion of matter and its piecewise structure. Development of dense GPS-networks allowed to experimentally confirm the concept of block structures of the geophysical environment and to prove rotary character of block movement. An analysis of both the migration of earthquake sources and the movement of sections of tectonic plates’ borders has allowed to reveal general properties of such movements and to prove their wave nature. It is shown that within the limits of rotational model, blocks and plates are interconnected among themselves by the elastic long-range fields forming a uniform planetary geodynamic field. It is offered to use the geodynamic solutions of rotational model in the one class of phenomena as a basis at the construction of a new geological paradigm — wave moment geodynamics. 相似文献
25.
V. B. Kurnosov 《Lithology and Mineral Resources》2017,52(6):467-478
The paper presents the results of the study of variations in the content of macro- and microelements (rare earth elements included) in the Upper Pleistocene sediments from DSDP Hole 477. The variations took place at the depth interval 110–191 m in the course of temperature drop to about 100°C in the upper part of the hydrothermal system. Variations in the content of most chemical elements in sediments from DSDP Hole 477 are manifested more weakly than in the underlying sediments of the interval 191–267 m of DSDP Hole 477A that were altered at a temperature of about 300°C. For many chemical elements, influence of the sedimentary cover on the compositional transformation of solutions during their interaction with sediments attenuates with the cooling of its upper part to the point of its complete termination. 相似文献
26.
Community Structure in the Amber Forest: Study of the Arthropod Syninclusia in the Rovno Amber(Late Eocene of Ukraine) 总被引:1,自引:1,他引:0
Evgeny E.?PERKOVSKY Alexandr P.?RASNITSYN Аnatoly P. VLASKIN Sergej P.?RASNITSYN 《《地质学报》英文版》2010,84(4):954-958
<正>Arthropodan syninclusions in the Late Eocene Rovno amber were examined using x~2 to reveal correlation of the component groups(some taxa of Diptera,ants,aphids,and mites) supposedly indicative of the biocoenotic relationships in the ancient amber forest.Three tightly correlated groups were identified,representing a putative aerial plankton guild(Chironomidae+Ceratopogonidae) and two tree-trunk guilds,one of which (Dolichopodidae+Germaraphis) is possibly connected to more open or/and more hygrophilous habitats than the other(Sciara zone Diptera +"Acarus"rhombeus).The ants were not linked with any of the above components. 相似文献
27.
P. Comodi A. Kurnosov S. Nazzareni L. Dubrovinsky 《Physics and Chemistry of Minerals》2012,39(1):65-71
The effects of pressure on the dehydration of gypsum materials were investigated up to 633 K and 25 GPa by using Raman spectroscopy
and synchrotron X-ray diffraction with an externally heated diamond anvil cell. At 2.5 GPa, gypsum starts to dehydrate around
428 K, by forming bassanite, CaSO4 hemihydrate, which completely dehydrates to γ-anhydrite at 488 K. All the sulphate modes decrease linearly between 293 and
427 K with temperature coefficients ranging from −0.119 to −0.021 cm−1 K−1, where an abrupt change in the ν3 mode and in the OH-stretching region indicates the beginning of dehydration. Increasing the temperature to 488 K, the OH-stretching
modes completely disappear, marking the complete dehydration and formation of γ-anhydrite. Moreover, the sample changes from
transparent to opaque to transparent again during the dehydration sequence gypsum-bassanite-γ-anhydrite, which irreversibly
transforms to β-anhydrite form at 593 K. These data compared with the dehydration temperature at room pressure indicate that
the dehydration temperature increases with pressure with a ΔP/ΔT slope equal to 230 bar/K. Synchrotron X-ray diffraction experiments show similar values of temperature and pressure for the
first appearance of bassanite. Evidence of phase transition from β-anhydrite structure to the monazite type was observed at
about 2 GPa under cold compression. On the other hand at the same pressure (2 GPa and 633 K), β-anhydrite was found, indicating
a positive Clausis-Clayperon slope of the transition. This transformation is completely reversible as showed by the Raman
spectra on the sample recovered after phase transition. 相似文献
28.
A two-stage evolution model for the Amantaytau orogenic-type gold deposit in Uzbekistan 总被引:4,自引:0,他引:4
Jan Pasava Hartwig Frimmel Anna Vymazalová Petr Dobes Alexandr V. Jukov Rustam I. Koneev 《Mineralium Deposita》2013,48(7):825-840
A lithogeochemical, mineral chemical, isotopic, and fluid inclusion study of barren, low-, and high-grade Au-mineralized samples from the shear zone-hosted Amantaytau gold deposit, Uzbekistan, shows that the local host rocks, Late Ordovician–Earlz Silurian carbonacous shales, are likely to have been an important source of Au, As, Ni, and S in the formation of the deposit. Syn-depositional pyrite in these shales contains on average 0.23 ppm Au, 1,083 ppm As, and 861 ppm Ni. The distribution of rare earth elements (REE) indicates a homogeneous source of light REE, whereas the heavy REE distribution reflects most likely primary variations in the sediments. The mineralized zone is marked by a positive Eu anomaly, which supports reducing conditions during the mineralization. A hydrothermal overprint by an aqueous–carbonic fluid is reflected in a high-grade Au-mineralized sample by δ13C values of ?13.0?‰ (V-PDB). The δ 34S values in pyrite (?0.13 to +7.30?‰ CDT) from barren and mineralized samples are consistent with marine sulfate being the principal source of the ore sulfur. Assuming a formation temperature of between 300 and 400 °C for the main stage of mineralization, as indicated by the alteration mineral assemblage, the calculated δ 18Ofluid is between 9.5 and 13.4?‰ V-SMOW, which points at a metamorphic origin of the ore fluid. 相似文献
29.
Two new genera with two new species of sawflies, Cathayxyela extensa gen. et sp. nov. and Aequixyela immensa gen. et sp. nov., from the Middle Jurassic Jiulongshan Formation of southeastern Inner Mongolia, China, are assigned to the subfamily Xyelinae (Hymenoptera, Xyelidae). Cathayxyela gen. nov. can be distinguished by the third antennal article longer than the head; mesoprescutum and mesoscutellum nearly equal in length; the forewing with Sc meeting C before the junction of 1-M and 1- Rs; a weak and narrow pterostigma; and 3-Cu at least 1.5 times longer than the lm-cu. Aequixyela gen. nov. is characterized by the third antennal article nearly as long as the head; the forewing with Rs+M approximately equal to 2-Rs in length; 2m-cu inclined toward the wing base and nearly reaching the middle of cell 3rm; lm-cu as long as the 2-Cu and 3-Cu; and the cell 2cua of regular hexagonal shape. 相似文献
30.
Lithology and Mineral Resources - Clay minerals in Holocene–Pleistocene sediments from Hole 858B DSDP drilled at 20 m from the black smoker in the Dead Dog hydrothermal field, axial valley of... 相似文献