Wyniki wyszukiwania - BazTech

1

Cluster analysis of existing technoparks in developed countries

Shaidurova Natalia, Prajova Vanessa, Smirnov Vitaliy, Livenskaya Galina

Management Systems in Production Engineering

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2021

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nr 4 (29)

294--301

EN

This article provides a cluster analysis of existing technoparks, the sample of which was built according to the completeness of the data presented on the official websites of the Ministry of Industry and Trade of the Russian Federation and the terms of operation. The analysis is carried out in order to determine the best components of the effectiveness of the development of the technopark movement in Russia. According to the analysis of this article, we can talk about a weak relationship between the three sub-indices: the activities of the management company, the activities of residents, the activities of regional authorities. The obtained data can serve as a starting base for further construction of an econometric model of the efficiency factors of technoparks.

2

Using of numerical methods for calculation the equation for cluster concentration in gaseaus materials

Bublikov A., Denisova N., Segeda T.

Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska

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2013

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nr 4

59--62

EN

This article describes cluster model of gaseous materials and prospects of using the model. Equations set for the calculation of different sizes clusters concentrations are presented. The authors produce numerical solution of the equation set. Results of the numerical solution are compared with the results that derived from analytical solution.

PL

Ten artykuł zawiera opis modelu klastrowego materiałów gazowych i analiza perspektywy jego zastosowania. Przedstawiono układ równań do obliczania koncentracji klastrów różnych rozmiarów. Autorzy przedstawiają rozwiązanie numeryczne danego układu. Wyniki rozwiązania numerycznego są porównane z wynikami otrzymanymi metodami analitycznymi.

3

Quantum chemical models of defects in thin silicon films

Dzelme J., Zapol B. P., Misiuk A.

Opto-Electronics Review

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2000

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Vol. 8, No. 4

292-294

EN

Cluster models and quantum chemical methods were used to investigate electronic structure and properties of defects in silicon, including extended defects of crystals, such as surface and interphases dislocations, which create regions of compression anf strain. Pressure effect was simulated by reduction of the lattice constant. This approach is adequate for investigation of thin films. Reduce influence of chemical bonding and enhanced use of free volume during O migration under high pressures have been shown. The Si and O interstitial migration activation energies were estimated as 4.21 eV and 2.73 eV, respectively, the former being indifferent to pressure.

4

Cluster model studies on catalytic properties of vanadium pentoxide

Witko M., Tokarz R., Hermann K.

Polish Journal of Chemistry

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1998

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Vol. 72, nr 7S

1565-1583

EN

ZINDO cluster model calculation are performed to study the electronic structure and chemical reactivity of the V2O5(010) surface. Inter-atomic binding in vanadium pentoxide is determined to be of a mixed ionic and covalent character. The calculations reveal the difference in the catalytic propertoes between structurally inequivalent surface oxygen centers and show the increased local reactivity of bridging oxygens with respect to the electrophilic adparticles. Convergence of the electronic properties with respect to the cluster size is achieved for cluster as large as V10O31H12. The effect of the second substrate layer on the surface electronic properties is found to be negligile. Further, rather similar electronic parameters of the V10O31H12 cluster in its idealized, bulk and optimized geometry are obtained. The H/H(+) species adsorb at the V2O5(010) surface, always at oxygen sites, forming very stable surface hydroxyl groups. The strongest binding occurs with the oxygen O(c) bridging two bare vanadium atoms. These O(c) oxygens become quite mobile in presence of the H/H(+) adparticle. Allowing the surface oxygen to ralax during adsorption of H/H(+) leads to different adsorption scenarios depending on the surface oxygen site. At the vanadyl oxygen site a very stable and rigid hydroxyl group O(A)H is formed above the vanadium center. At the doubly coordinated oxygen site O(b) the adsorbate penetrates between two vanadyl groups to form a local O(b)H group, while at the O(c) site an O(c)H group is created (slightly above the surface O(c) position), where O-H binding is strongest. Weak initial interaction, between triply coordinated oxygen O(d,e) and the incoming H/H(+) species, leads to stabilizaton of the adsorbate near the closest vanadyl site resulting in a tilted O(a)H group instead of O(d) H or O(e)H.