Diagrams of electrochemical equilibria of the system copper-potassium ethylxanthate-water at 25°C     

Tadeusz Hepel  Andrzej Pomianowski 《International Journal of Mineral Processing》1977,4(4):345-361

On the basis of thermodynamic calculations, diagrams of metastable electrochemical equilibria of the system copper-potassium ethylxanthate-water, at 25°C were constructed. The equilibria equations and diagrams for the total activity of [EtX^?] + [HEtX] + 2 [(EtX)₂] (equalling 10^?1, 10^?4 and 10^?7 mol/dm³), are presented. The practical conclusions resulting from these diagrams for the flotation of native copper are discussed.  相似文献   

GEOGRAPHY IN MEXICO     

Jerry P. Schofer  Silvana Levi  Efrain Pena Villada  Andrzej M. Zeronski 《The Professional geographer》1990,42(3):380-382

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Non-integrability of the three-body problem     

Andrzej J. Maciejewski  Maria Przybylska 《Celestial Mechanics and Dynamical Astronomy》2011,110(1):17-30

We consider the planar problem of three bodies which attract mutually with the force proportional to a certain negative integer power of the distance between the bodies. We show that such generalisation of the gravitational three-body problem is not integrable in the Liouville sense.  相似文献   

EC 11481–2303—a peculiar subdwarf OB star revisited     

Thomas Rauch  Klaus Werner  Jeffrey W. Kruk 《Astrophysics and Space Science》2010,329(1-2):133-139

EC?11481–2303 is a peculiar, hot, high-gravity pre-white dwarf. Previous optical spectroscopy revealed that it is a sdOB star with T _eff=41?790 K, log?g=5.84, and He/H = 0.014 by number. We present an on-going spectral analysis by means of non-LTE model-atmosphere techniques based on high-resolution, high-S/N optical (VLT-UVES) and ultraviolet (FUSE, IUE) observations.We are able to reproduce the optical and UV observations simultaneously with a chemically homogeneous NLTE model atmosphere with a significantly higher effective temperature and lower He abundance (T _eff=55?000 K, log?g=5.8, and He/H=0.0025 by number). While C, N, and O appear less than 0.15 times solar, the iron-group abundance is strongly enhanced by at least a factor of ten.  相似文献   

Seasonal transport pattern of chromium(III and VI) in a stream receiving wastewater from tanneries     

Ewa Szalinska  Janusz Dominik  Davide A.L. Vignati  Andrzej Bobrowski  Boguslaw Bas 《Applied Geochemistry》2010

Water, suspended matter and sediment samples from a system heavily impacted by wastewater from numerous small tanneries (the upper Dunajec River, southern Poland) were collected to establish the annual cycle of Cr. To study possible oxidation processes the speciation of Cr and Mn concentrations were also investigated. This study showed that Cr(III and VI) temporal and spatial distributions are regulated by coupled anthropogenic (source location and emissions) and hydrologic factors (water flow and particle transport). Chromium(III) concentrations in all compartments varied seasonally as a function of the hydrological regime, production cycle in tanneries and distance from the discharge location. Cr(III) was largely associated with the particulate phase and rapidly deposited in river bed sediments. Contaminated river sediments were however flushed during flood periods to the reservoir located downstream from tanneries. During the tanning season (November to March), Chromium(III) concentrations in the water column and total Cr concentration in sediments exceeded relevant ecotoxicological guidelines only upstream from the reservoir, which trapped about 70% of the annual Cr(III) load transported by the Dunajec river. A correlation between Cr(VI)/Cr(III) ratios and Mn concentration in sediments downstream from the reservoir suggests the possibility of Cr(III) oxidation in natural conditions.  相似文献   

Continental crust in Gorny Altai: nature and composition of protoliths     

N.N. Kruk  A.G. Vladimirov  G.A. Babin  S.P. Shokalsky  N.V. Sennikov  S.N. Rudnev  N.I. Volkova  V.P. Kovach  P.A. Serov 《Russian Geology and Geophysics》2010,51(5):431-446

The history of the Vendian–Early Paleozoic formation of protoliths of continental crust in the Gorny Altai segment of the Central Asian fold belt is considered, and their composition, isotopic characteristics, and formation mechanisms are estimated. We have established two stages of crust-forming processes in Gorny Altai: Early and Late Caledonian, with the different structures of formed geoblocks and nature and compositions of crustal protoliths. At the Early Caledonian stage, fragments of oceanic lithosphere of basic composition (MORB, OIT, OIB) (T_Nd(DM-2st) = 0.65–1.1 Ga) formed, as well as island arcs with andesite-basaltic and andesitic protoliths with low contents of incompatible elements (T_Nd(DM-2st) = 0.7–0.9 Ga). At the Late Caledonian stage, the redistribution of the substance of these blocks and the external supply of material led to the formation of heterogeneous crust of turbidite basins with an oceanic basement and andesite-dacitic upper-crustal protoliths (T_Nd(DM-2st) varies from 0.8–0.9 Ga in the framing of the volcanic arc of Altaids to 1.4–1.6 Ga at the boundary of the Altai–Mongolian microcontinent).  相似文献   

Nd isotope systematics in metamorphic rocks of the southern Russian Far East     

N. N. Kruk  V. P. Kovach  V. V. Golozubov  S. A. Kasatkin  L. B. Terent’eva  S. N. Lavrik 《Doklady Earth Sciences》2014,455(1):233-237

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Numerical modeling and neural networks to identify model parameters from piezocone tests: I. FEM analysis of penetration in two‐phase continuum     

Rafał F. Obrzud  Andrzej Truty  Laurent Vulliet 《国际地质力学数值与分析法杂志》2011,35(16):1703-1730

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Pure cross-anisotropy for geotechnical elastic potentials     

Niemunis  Andrzej  Staszewska  Katarzyna 《Acta Geotechnica》2022,17(5):1699-1717

The pure cross-anisotropy is understood as a special scaling of strain (or stress). The scaled tensor is used as an argument in the elastic stiffness (or compliance). Such anisotropy can be overlaid on the top of any elastic stiffness, in particular on one obtained from an elastic potential with its own stress-induced anisotropy. This superposition does not violate the Second Law. The method can be also applied to other functions like plastic potentials or yield surfaces, wherever some cross-anisotropy is desired. The pure cross-anisotropy is described by the sedimentation vector and at most two constants. Scaling with more than two purely anisotropic constants is shown impossible. The formulation was compared with experiments and alternative approaches. Static and dynamic calibration of the pure anisotropy is also discussed. Graphic representation of stiffness with the popular response envelopes requires some enhancement for anisotropy. Several examples are presented. All derivations and examples were accomplished using the algebra program Mathematica.

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Conditions of carbonation and wehrlitization of lithospheric peridotite upon interaction with carbonatitic melts     

A. G. Sokol  A. N. Kruk  D. A. Chebotarev  Yu. N. Palyanov  N. V. Sobolev 《Doklady Earth Sciences》2015,465(2):1262-1267

Study of the mechanism of carbonation and wehrlitization of harzburgite upon metasomatism by carbonatitic melts of various genesis was carried out. Experiments with durations of 60–150 h were performed at 6.3 GPa and 1200°C. The data showed that carbonatite with MgO/CaO > 0.3 percolating into the peridotitic lithosphere may provide crystallization of magnesite in it. The influence of all studied carbonatites results in wehrlitization of peridotite. The compositions of melts formed by interaction with harzburgite (～2 wt % SiO₂, Ca# = 36–47) practically do not depend on the composition of the initial carbonatite. Based on the data obtained, we conclude that the formation of magnesite-bearing and magnesite-free metasomatized peridotites may have a significant influence on the CO₂ regime in the further generation of kimberlitic magmas of groups I and II.  相似文献