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We consider the planar three-body problem and prove that, apart from some exceptional cases, there is no additional first integral meromorphic with respect to positions, mutual distances and momenta.  相似文献   
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We present a preliminary analysis of medium resolution optical spectra of comet C/2000 WM1 (LINEAR) obtained on 22 November 2001. Theemission lines of the molecules C2, C3, CN, NH2,H2O+ and presumably CO (Asundi and triplet bands) and C2 -were identified in these spectra. By analysing the brightnessdistributions of the C2, C3, CN emission lines along theslit of the spectrograph we determined some physical parameters of theseneutrals, such as their lifetimes and expansion velocities inthe coma. The Franck–Condon factors for the CO Asundi bands and C2 - bands were calculated using a Morse potential model.  相似文献   
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The physical and mathematical models were used to study the method of acid retardation for separating acids from their salts in concentrated multicomponent solutions using nanoporous sorption materials. A combined mechanism of separation relies on the fact that in the sorption phase having a low dielectric permittivity, smaller-sized acid particles, namely, the molecules or strongly bound and weakly hydrated ion pairs, can penetrate the nanopores and are retained within these pores due to molecular sorption or competitive solvation forces. The dissolved salts presented by highly hydrated ions or weakly bound ion pairs can easily pass through the porous medium with a flow of concentrated solution, which is pumped through the column packed with the granulated bed of gel-type ion exchange resins or hypercrosslinked polymers. In conventional cyclic AR processes, purified acid is desorbed by water according to the mechanism of competitive solvation. However, such processes can be successfully used only when the salts separated from acids are highly soluble, as is the case with chloride and nitrate solutions free of components that may form compounds insoluble in neutral medium. At the separation in real sulfate and phosphate media, which normally contain alkaline earth metals and other components, conventional AR- based technologies proved to be unsuccessful. The new modified version of acid retardation is based on the previously discovered effect of stabilization of colloidal systems and supersaturated solutions in porous ion exchange media. A distinctive feature of the proposed technique is the use of weakly acidic aqueous solutions, instead of water, at the stages of acid displace in the cyclic AR processes. The proposed technique of WPA purification using strong-base gel-type ion exchangers in the phosphate form opens up the possibility of stable and feasible processes of acid separation and purification with simultaneous extraction of valuable components, e.g., REE concentrate.  相似文献   
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A new estimate of global methane emission into the atmosphere from mud volcanoes (MVs) on land and shallow seafloor is presented. The estimate, considered a lower limit, is based on 1) new direct measurements of flux, including both venting of methane and diffuse microseepage around craters and vents, and 2) a classification of MV sizes in terms of area (km2) based on a compilation of data from 120 MVs. The methane flux to the atmosphere is conservatively estimated between 6 and 9 Mt y–1. This emission from MVs is 3–6% of the natural methane sources and is comparable with ocean and hydrate sources, officially considered in the atmospheric methane budget. The total geologic source, including MVs, seepage from seafloor, microseepage in hydrocarbon-prone areas and geothermal sources, would amount to 35–45 Mt y–1. The authors believe it is time to add this parameter in the Intergovernmental Panel on Climate Change official tables of atmospheric methane sources.GEM  相似文献   
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Small euhedral chromite crystals are found in olivine macrophenocrysts (Fo80–84) from the basaltic andesites (150 ppm Cr) erupted in 1943–1947, and in orthopyroxene macrophenocrysts of the andesites (75 ppm Cr) erupted in 1947–1952. The majority of the chromite octahedra are 5–20 μm in diameter, and some are found in clusters and linear chains of three or more oriented chromite crystals. The composition of the majority of the chromite grains within olivine and orthopyroxene macrophenocrysts is Fe2+/(Fe2++Mg)=0.5–0.6, Cr/(Cr+Al)=0.5–0.6 and Fe3+/(Fe3++Al+Cr)=0.2–0.3. The chromite crystals in contact with the groundmass are larger, subhedral, and grade in composition from chromite cores to magnetite rims. Comparison of the composition of chromite with those of other volcanic rocks shows that the most primitive Paricutin chromite is richer in total iron and higher in Fe3+/(Fe3++Al+Cr) than primary chromite in most lavas. The linear chains of oriented chromite octahedra are found in olivine and orthopyroxene macrophenocrysts, and in the groundmass. These chromite chains are thought to result from diffusion-controlled crystallization because of the very high partition coefficient (1000) of Cr between chromite and melt. We conclude that chromite was a primary phase in the lavas at the time of extrusion and that magnetite only crystallized after extrusion during cooling of the lava flows. The presence of chromite microphenocrysts in andesitic lavas containing as little as 70 ppm Cr can be explained by dissolved H2O in the melt depressing the liquidus temperature for orthopyroxene such that chromite becomes a liquidus phase. The influence of dissolved H2O can also explain the lack of plagioclase macrophenocrysts in most of the lavas and the relatively high partition coefficient (20) of Ni between olivine and melt and the high partition coefficient (40) of Cr between orthopyroxene and melt. The liquidus temperature of the basaltic andesite is estimated to have been less than 1140°C, assuming H2O>1 wt.%, and the log fO2 to have been above that of the QFM buffer. The chromite and orthopyroxene liquidus temperature of the andesites, assuming H2O>1 wt.%, is estimated to have been 1100°C or less. The derivation of the later andesites from the earlier basaltic andesites has been explained by a combination of fractional crystallization of olivine, orthopyroxene and plagioclase, and assimilation of xenoliths. The significantly lower Cr, Ni and Mg of the andesites may have been in part due to the separation of olivine macrophenocrysts plus enclosed chromite crystals from the earlier basaltic andesites.  相似文献   
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