New ruthenium complex 3,3-(Ph
2
P(CH
2
)
4
PPh
2
)-3-H-3-Cl-9-Me-
closo-
3,1,2-RuC
2
B
9
H
10
(
1
) and its derivatives 3,3-(Ph
2
P(CH
2
)
4
PPh
2
)-3-Cl-9-Me-
closo-
3,1,2-RuC
2
B
9
H
10
(
2
), ...3,3,8-(Ph
2
P(CH
2
)
4
PPh-μ-
(
3
), and 3,3,4,8-(Ph
2
P(CH
2
)
4
P-μ-
(
4
) have been prepared from
nido
-carborane ligand 5-Me-7,8-C
2
B
9
H
11
–
containing methyl substituent in the lower belt of basket. The obtained substituted ruthenacarboranes retain geometries and steric configurations of the metal atom typical of unsubstituted analogs, but are characterized by lower values of the Ru(II)–Ru(III) redox potential. The high efficiency of the resulting derivatives as catalysts for controllable methyl methacrylate radical polymerization has been shown.
Transient processes in gravimetric data spanning more than 12 years are considered. During this time, more than 15 trips were made from the fundamental gravimetric point Ledovo to the first class ...point Zapolskoe and back using two CG 5 Autograv automated relative gravimeters. The most significant parameters that affect the readings of the instruments were identified: ambient temperature, the values of the zero drift of the sensing element of the gravimeter, and the direct increment of gravity. The zero drift was taken into account using a second-order polynomial prediction, and the remaining two parameters were described by a logarithmic dependence. The natural logarithm equation allows describing the functions by measuring the coefficient before the logarithm (logarithmic) and additional (linear). The value of the logarithmic coefficients characterizing the duration of transient processes has a linear dependence on temperature, which means that it can characterize the measurement time at the point in the case of a significant temperature change. The magnitude of the linear coefficients characterizing the increase in gravity depends linearly on temperature when the instruments are moved to a colder environment. When the instruments are moved to a warmer environment (10°), the dependence becomes more complex, possibly random, which also requires an increase in the measurement time at the point. The usual duration of measurements at gravimetric stations is 10 min. The relevance of taking temperature into account at measurement points depends on the required accuracy, for example, for a temperature difference of 10°C, the RMS of gravimetric measurements was ±0.025 mGal.
Abstract
The success of the development of lands disturbed by open pit mining largely depends on the correct selection of the assortment of master plants, which are distinguished by good survival ...rate and high productivity. Overburden rocks, turned up on the day surface, in the initial years are insignificantly overgrown with natural vegetation. They are affected by water and wind erosion under the influence of climate, environmental conditions and anthropogenic impacts. Perennial grasses have the ability to grow rapidly, accumulate a large amount of aboveground and underground mass, improve the physical properties of rocks and accumulate soil fertility in them. When selecting different types of grasses for sowing on overburden rocks, it is necessary to take into account their biological characteristics.
The study of the effect of plants with different type of mycorrhizal symbiosis on carbon, nitrogen, and phosphorus transformation in soils is important in view of the necessity to predict changes in ...nutrient cycles upon transformation of the structure of plant communities under changing environmental conditions. The impact of dwarf shrubs (
Empetrum hermaphroditum
,
Vaccinium myrtillus
,
Vaccinium uliginosum
, and
Vaccinium vitis-idaea
) with ericoid mycorrhiza (ERM) and shrub (
Betula nana
) with ectomycorrhiza (ECM) on the properties of Umbric Leptosol of grass meadow in tundra of the Khibiny Mountains has been studied. It is shown that the presence of plants with ERM and ECM causes an increase in the content of labile mineral and organic phosphorus and of extractable organic nitrogen in soil and in the C/N ratio in the microbial biomass and a decrease in the content of nitrates, N-mineralization and nitrification activity, and the C/N and C/P ratios in the extractable organic matter. The increased activity of glucosidase, chitinase, and phosphatase testifies to high activity of exoenzymes of ERM fungi even in soil with high availability of inorganic nitrogen and phosphorus.
In this paper, we present a new mathematical model of the interaction of two languages. In the model, we distinguish percentages of people who speak a non-target language, a target language with low ...and high proficiency, and both languages considering the low and high proficiency levels in the target language. Therefore, the solution consists of five fields. Furthermore, we assume the diffusive and convective spread of the languages, considering the overflow between them. Thus, the mathematical model is defined by a coupled system of partial differential equations for the five fields.
Since the mathematical model is coupled and the medium is heterogeneous, we have implemented a multiscale method. The proposed multiscale method is based on the Generalized Multiscale Finite Element Method (GMsFEM). In addition to offline multiscale basis functions, we also construct online multiscale basis functions. The online basis functions can account for changes in the heterogeneity of the medium caused by migration flows. Numerical results have shown that such online enrichment can significantly improve the accuracy of multiscale modeling.
In this paper, we propose a new mathematical model of language interactions considering bilingualism. We assume diffusive and convective language spreads with language exchange terms. The resulting ...model consists of a coupled system of partial differential equations for three functions. We develop a finite element approximation of the mathematical model using implicit and partially explicit time schemes. In addition, we present a partial learning approach for this problem using a partially explicit discretization. In this method, we train a Deep Neural Network to predict the values of the difficult-to-compute (implicit) part of the solution at some observed points. We then perform linear temporal interpolation and spatial interpolation using the Proper Orthogonal Decomposition (POD) and the Discrete Empirical Interpolation Method (DEIM).
To test the proposed approach and the model, we consider two model problems. Each of them simulates different language situations. For each problem, we compute the relative errors of the proposed approach and define the different parts of the error. The numerical results show that the proposed approach can provide good accuracy while reducing computational costs.
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