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11.
G. Lujanienė P. Beneš K. Štamberg K. Jokšas I. Kulakauskaitė 《Journal of Radioanalytical and Nuclear Chemistry》2013,295(3):1957-1967
Sorption of Am and Pu isotopes to bottom sediments of the Baltic Sea has been studied under natural and laboratory conditions. Data obtained from sequential extraction, sorption of Am(III), Pu(IV) and Pu(V) as well as oxidation state distribution experiments have shown that Pu(V) sorption mechanism includes a very fast Pu(V) reduction (reaction rate ≤ 2.33 × 10?3 s?1) to Pu(IV) by humic substances and/or by Fe(II) to Pu(IV) and partly to Pu(III). Following reduction Pu isotopes were bound to various components of bottom sediments via ion exchange and surface complexation reactions and a slow incorporation into the crystalline structure of Fe minerals. Kinetics experiments showed that the sorption of Pu(V), Pu(IV) and Am(III) to bottom sediments from natural seawater was controlled by the inert layer diffusion process. 相似文献
12.
Feliksas Ivanauskas Albertas Malinauskas Liana Stonkienė 《Journal of mathematical chemistry》2014,52(8):2020-2029
We extend our previous model taking into account a possible autoacceleration mechanism of electrochemical processes. It is supposed that protons generated in an electrochemical oxidation of ascorbate are responsible for an increase of electric conductivity of polyaniline. Accordingly, the current–time profiles have been calculated taking into account a “threshold” value for proton concentration to increase the electric conductivity of polyaniline by one or more orders of magnitude. Different kinds of corresponding profiles, including ones with a sigmoid character and possessing sharp current flashes as well, were obtained and analyzed. 相似文献
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14.
We obtain nonuniform estimates depending on the interval length for Poisson and compound Poisson approximations to 2-runs.
We calculate exact constants for the estimates in the Wasserstein metric. 相似文献
15.
We describe a modal sequential calculus some modal rules of which do not contain duplications of the main formula. We also prove its equivalence to the modal calculus S4 and the decidability of some classes of formulas containing only oneplace predicate variables. 相似文献
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18.
A. Aleškevičienė 《Lithuanian Mathematical Journal》2010,50(1):1-12
In this paper, we consider the Sparre Andersen insurance risk model with initial surplus x > 0. Let Ax denote the deficit at the time of ruin. Assuming that the tail probabilities of claim size are regularly varying, the second-order
asymptotic of the deficit distribution and its moments at the time of ruin are derived. 相似文献
19.
Changes of the radioactive decay rate of71Ge (T 1/2=11.43 days) have been studied experimentally for71Ge in some compounds of bivalent and quadrivalent germanium. Relative changes Δλ/λ of the electron capture probability have been measured, and the chemical changes Δρ(0) of the electron density at the germanium nuclei have been determined from these measurements. Values for the Mössbauer isomer shift calibration constants for the 67 keV γ-transition of73Ge have been estimated:C=δ/Δρ(0)=(0.061±0.020) mm·s?1/a.u., Δ〈r 2〉=(21±7)·10?3 fm2, ΔR/R=(6.9±2.3)·10?4. 相似文献
20.
We develop a finite-difference scheme for approximation of a system of nonlinear PDEs describing the Q-switching process.
We construct it by using staggered grids. The transport equations are approximated along characteristics, and quadratic nonlinear
functions are linearized using a special selection of staggered grids. The stability analysis proves that a connection between
time and space steps arises only due to approximation requirements in order to follow exactly the directions of characteristics.
The convergence analysis of this scheme is done in two steps. First, some estimates of the uniform boundedness of the discrete
solution are proved. This part of the analysis is done locally, in some neighborhood of the exact solution. Second, on the
basis of the obtained estimates, the main stability inequality is proved. The second-order convergence rate with respect to
the space and time coordinates follows from this stability estimate. Using the obtained convergence result, we prove that
the local stability analysis in the selected neighborhood of the exact solution is sufficient. 相似文献