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81.
A combined approach (endohedral doping and exohedral environment) to stabilization of boron clusters with classical fullerene structures has been studied. The boron clusters with classical fullerene structures are stable when heteroatomic part of the complex (endohedral atom and exohedral environment) donates in total 18 electrons to the composite system, stability of which depends on the coordination capabilities and donor ability of the endohedral and surrounding atoms. The most effective stabilization is achieved in the case of the endohedral transition metals atoms, whereas the most effective environment is given by the lithium surrounding.
相似文献82.
N. V. Chezhina E. V. Bodritskaya N. A. Zhuk 《Russian Journal of General Chemistry》2008,78(6):1127-1132
Magnetic susceptibility of dilute solid solutions of lanthanum gallates doped with nickel and also with nickel and strontium was studied. Calculations showed that the main contribution into the exchange interactions in gallates doped with nickel is made by dimers formed by low-spin nickel(III) (J-20 cm?1), and in gallates doped with strontium and nickel the main contribution is due to dimers formed by high-and low-spin nickel (J 10 cm?1). Electrical conductivity measurements showed that the samples under study are electron and ion conductors. 相似文献
83.
N. A. Zhuk I. V. Piir A. L. Pimenov N. V. Chezhina 《Russian Journal of General Chemistry》2008,78(3):335-340
Magnetic susceptibility and electrophysical properties of copper-containing solid solutions with the structure of bismuth
niobate, Bi5Nb3O15, were studied. Paramagnetic aggregates (dimers) of copper atoms are formed in the solid solutions, their fraction substantially
exceeding the statistically probable value. The parameters of exchange interactions in the dimer clusters of copper atoms
and the distribution of monomers and dimers in the solutions were calculated. The exchange parameter of antiferromagnetic
interactions between copper atoms in the dimers is −210 cm−1.
Original Russian Text ? N.A. Zhuk, I.V. Piir, A.L. Pimenov, N.V. Chezhina, 2008, published in Zhurnal Obshchei Khimii, 2008,
Vol. 78, No. 3, pp. 353–357.
For communication IV, see [1]. 相似文献
84.
Ruslan?K.?MuharlyamovEmail author Tatiana?N.?Pankratyeva 《International Journal of Theoretical Physics》2016,55(2):1093-1104
We investigate the Bianchi type-I cosmological model with the scalar and electromagnetic fields possessing non-minimal couplings. They contain the Mie invariant that leads to the flat Friedman’s cosmological model. We found the lagrangian for interaction, which the isotropization process of the expansion takes place. Two cases are considered, when the Mie invariant is constat or time-dependent. We study the canonical scalar field and the phantom one. 相似文献
85.
Yashin R Rudchenko S Stojanovic MN 《Journal of the American Chemical Society》2007,129(50):15581-15584
Microparticles covered with DNA-based computing elements that sense inputs and release oligonucleotides as outputs could be used to construct autonomous networks with increasingly complex functions. We demonstrate cascades of particles with up to three layers and a nonlinear network with an AND gate hub. In order to establish functional networks, particles do not have to be in direct physical contact. 相似文献
86.
McCullough DH Grygorash R Hsu JT Regen SL 《Journal of the American Chemical Society》2007,129(27):8663-8667
Permeation measurements have been made for He, CO2, and N2 across single Langmuir-Blodgett (LB) bilayers derived from 1,2,4,5-tetrakis[(N-(undecanoamidoethyl)-N,N-dimethyl ammonium) methyl]benzene tetrabromide (2) and 1,2,4,5-tetrakis[(N-(perfluoroundecanoamidoethyl)-N,N-dimethyl ammonium)methyl]benzene tetrabromide (3) in the absence and in the presence of entrapped poly(acrylic acid) (PAA). In the absence of PAA, single LB bilayers of 3 show a higher permeance for He and N2 but a lower permeation rate of CO2, as compared with analogous LB bilayers made from 2. The relatively low permeation rate of CO2 for the former has been attributed to reduced associative interactions with the fluorocarbon-rich bilayer. The same behavior has also been observed for LB bilayers containing PAA, formed under conditions that yield glued bilayers of 2 and 3 having similar diffusional pathways, as judged by He/N2 selectivities. These results, together with the fact that glued bilayers of 2 (having a thinner PAA layer as compared with those made from 3) exhibit lower He and N2 permeances, provide compelling evidence that the main barrier for gas transport is the combination of surfactant plus PAA and not simply a thin PAA layer that is encased within the surfactant bilayer. 相似文献
87.
The problem of interaction of a rigid body and a boundary of a viscous fluid under acoustic wave propagation is investigated.
An example of the motion of a cylinder in the vicinity of a flat rigid wall caused by acoustic field forces is examined.
S. P. Timoshenko Institute of Mechanics, National Academy of Sciences of Ukraine, Kiev. Translated from Prikladnaya Mekhanika,
Vol. 35, No. 10, pp. 74–79, October, 1999. 相似文献
88.
Digital marketing has been extensively researched and developed remarkably rapidly over the last decade. Within this field, hundreds of scientific publications and patents have been produced, but the accuracy of prediction technologies leaves much to be desired. Conversion prediction remains a problem for most marketing professionals. In this article, the authors, using a dataset containing landing pages content and their conversions, show that a detailed analysis of text readability is capable of predicting conversion rates. They identify specific features that directly affect conversion and show how marketing professionals can use the results of this work. In their experiments, the authors show that the applied machine learning approach can predict landing page conversion. They built five machine learning models. The accuracy of the built machine learning model using the SVM algorithm is promising for its implementation. Additionally, the interpretation of the results of this model was conducted using the SHAP package. Approximately 60% of purchases are made by nonmembers, and this paper may be suitable for the cold-start problem. 相似文献
89.
The original theory of a proximity effect is proposed for the bi- and tri-layered system ferromagnetic metal/superconductor (F/S) in dirty limit. The F1/S/F2 trilayer is examined more closely. The distinctions in materials, in thicknesses of F layers (df1 and df2), in parameters interfaces, and in local environments of layers are considered among the causes of incommensurability of trilayer. The peculiar Tc(df1, df2) interference pattern is predicted for the F1/S/F2 systems. The reentrant superconductivity and possibility of the better observability of the spin-valve regime are discussed. 相似文献
90.
S. M. Zhuk 《Ukrainian Mathematical Journal》2009,61(2):214-235
We investigate the state estimation problem for a dynamical system described by a linear operator equation with unknown parameters
in a Hilbert space. In the case of quadratic restrictions on the unknown parameters, we propose formulas for a priori mean-square minimax estimators and a posteriori linear minimax estimators. A criterion for the finiteness of the minimax error is formulated. As an example, the main results
are applied to a system of linear algebraic-differential equations with constant coefficients. 相似文献