The paper presents result of ab initio methods exploiting to calculate the molar extinction spectrum of some model clusters, the molecular hybrid C
24
H
30
included. Based on the comparison of the ...calculation with the experimental spectra of the main allotropic modifications of carbon, the absorption maximum with an energy of ∼6 eV in the absorption spectrum of highly tetrahedral amorphous carbon (ta-C) attributed to the π → π* optical transitions of electrons in a single aromatic ring. The edge sites of the ring covalently bonded with the
sp
3
-hybridised carbon atoms of the amorphous matrix. The manifestation of a shoulder in the spectrum of the imaginary part of the refractive index of a film of highly tetrahedral amorphous carbon (ta-C), 4.6 eV, is assigned to π → π* optical transitions of clusters distorted with hybrid Stone–Wallace-like defect, also covalently bonded with the amorphous matrix.
Accounting for the different contributions of the aromatic rings, separated with
sp
3
bonds, with ab initio method we constructed the hybrid cluster C
73
H
74
which UV spectrum matches the most ...noticeable absorption band of 217.5 nm, known from astrophysical observations.
The spectral characteristics of hybtid cluster C
73
H
90
were calculated using the time-dependent Density Functional Theory method. The calculated spectrum demonstrates two maxima: at 5.7 and 3.8 eV, ...which are close to those in interstellar medium and laboretory experiments.
The article aims to investigate the issues concerning the definition of the big data concept, as well as the problem of civil turnover of big data in the legislation of the Russian Federation. ...Approaches to this definition enshrined in doctrinal legal acts and investigated in the legal literature are analyzed. The features and peculiarities of big data are considered. The conclusion about the need to legislate the basic categories in the field of big data to clarify the place of this object in the system of objects of civil rights is made. The study has also analyzed the risks of including big data in civil law turnover. Given the results, substantially practical approaches to regulating civilized forms of big data circulation should be the established mechanisms of civil liability for the use of big data that have resulted in derogation or limitation of the rights of citizens.
The density functional theory has been used to optimize the geometry and study the optical absorbance (molar extinction) spectra of molecular clusters based on C
32
H
24
and C
32
H
36
...diamondene–graphene hybrid fragments with dangling bonds compensated by the attachment of hydrogen. Calculated spectra were compared to the results of astrophysical observations. It is established that hybrid molecular clusters can contribute to formation of the well-known light extinction spectrum of the interstellar medium.
Introduction.
At present, stands with running drums are widely used for various types of tests. Power stands play a special role. Such stands take the mechanical power from the driving wheels of the ...car. This simulates the process of movement of the vehicle under operating conditions. Such equipment has various designs, principles of operation and performance. It is also used in tests that are different by purpose, development stages and types: research, control, certification, etc. Therefore, it is necessary in order to determine the traction-speed, fuel-efficient and environmental performance characteristics.
Materials and methods.
The paper provides the overview of the power stands with running drums, which are widespread on the domestic market. The authors carried out the analysis of the main structural solutions: schemes of force transfer between the wheel and the drum; types of loading devices; transmission layout schemes and features of the control and measuring complex. The authors also considered corresponding advantages and disadvantages, recommended spheres of application, demonstrated parameters and characteristics of the units’ workflow, presented components and equipment.
Discussion and conclusions.
The authors critically evaluate existing models of stands with running drums. Such information is useful for choosing serial models of stands and for developing technical tasks for designing or upgrading the equipment.
We describe a model of a stable, metal-modified heteromolecule based on a hybrid of diamondene and graphene containing hydrogen atoms for the stabilization of
sp
3
bonds. Hydrogen atoms were replaced ...by atoms of carbide-forming metals (Fe, Co, Ni). After the replacement of H atoms by Fe, Co, and Ni atoms in the initial heteromolecule and optimization of its geometry, it turned out that the resulting structure was stable. This result leads to the conclusion that metal atoms can be useful in the synthesis of diamondene and diamond.
We propose the idea of a heterostructure comprising a hybrid of diamondene and graphene and describe the principle of constructing these hybrids based on observed astrophysical data. A model is ...constructed, its geometry is optimized, and the stability of the molecule is estimated using the universal force field and ab initio methods.
Abstract
Nematic liquid crystal with polar terminal NCS group was studied by using acoustic and electro-optical methods. Experimental results on rotational viscosity have been obtained by two ...methods. The anisotropy of diamagnetic susceptibility of the studied LC with temperature variation was determined based on the comparison of these methods. The present results may be useful for testing physical models of the orientation dynamics of nematic liquid crystals in alternating electric and magnetic fields.
Optical Properties of Spiroid C300 Yastrebov, S. G.; Chekulaev, M. S.; Siklitskaya, A. V.
Technical physics,
2019/2, Letnik:
64, Številka:
2
Journal Article
Recenzirano
Calculation results of the electronic spectrum of carbon nanospiroid C
300
are presented. The π-electron structure of the spiroid is calculated using the strong coupling method, in which the matrix ...element of the exchange interaction of neighboring electrons (the resonance integral) is considered as being dependent on the local curvature of the spiroid surface. The optical absorption coefficient is calculated in the framework of the Tautz model and the result is compared with experimental and astrophysical observational data. The calculated and experimental data are in good agreement.
PDF
