Use of time scans of spectra in spectral analysis

Journal of Applied Spectroscopy -     

Field-theory approach to the disintegration of bound systems on the basis of a local gauge nature of an electromagnetic field

An approach is developed that makes it possible to take into account the structure of bound (nonlocal) matter fields in photodisintegration processes with allowance for the requirements of the fundamental principles of covariance and gauge invariance. The approach is based on employing the local U(1) gauge nature of an electromagnetic field, whose vector potential is identified with a connection that performs a parallel transportation of matter-field operators in a fiber space with an interior charge symmetry along “minimum” trajectories.     

Mn site substitution of La0.67Ca0.33MnO3 with closed shell ions: Effect on magnetic transition temperature

Mn site is substituted with closed shell ions (Al, Ga, Ti, Zr and a certain combination of Zr and Al) and also with Fe and Ru ions carrying the magnetic moment (S=5/2 and 2 respectively) at a fixed concentration of 5 at %. Substitution did not change either the crystal symmetry or the oxygen stoichiometry. All substituents were found to suppress both the metal-insulator and ferromagnetic transition temperatures (T _p(ρ) and T _C, respectively) to varied extents. Two main contributions identified for the suppression are the lattice disorder arising due to difference in the ionic radii between the substituent (r _M) and the Mn³⁺ ion (r _Mn ³⁺) and in the case of the substituents carrying a magnetic moment, the type of magnetic coupling between the substituent and that of the neighboring Mn ion.     

Relationship between the fine structure of polyethylene and the mechanism of plastic deformation and fracture

The relationship between the mechanism of deformation and fracture of linear polyethylene and the details of its fine structure is investigated. It is shown that the clearly expressed localization of both processes is a result of the anisotropy of the properties of the structural elements composing the spherulite and is controlled by their initial orientation in the spherulite relative to the axis of the tensile stress. A spiral model of the structure of polymer crystals is proposed and justified and used to develop a dislocation theory of the deformation and fracture of crystalline polymers.Mekhanika Polimerov, Vol. 4, No. 1, pp. 3–10, 1968     

Lamellar structure and plasticity micromechanisms in bulk crystalline polymers. Communication 2

Conclusions 1. It has been experimentally established that the deformation of crystalline polymers is accompanied by the shear transitions between lamellar crystals of different orientations characteristic of martensitic structures.2. It is concluded that the reversibility of the large deformations of linear polymers is martensitic in nature.For communication 1 see [1].E. O. Paton Electrowelding Institute, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Mekhanika Polimerov, No. 6, pp. 963–969, November–December, 1976.