Aminomethylation of 1-R-Tetrazoles

The reaction of tetrazole and a series of its 1-substituted derivatives with formaldehyde and alkylamines under mild conditions results in aminomethylation of the heterocyclic ring at the carbon atom with the formation of the corresponding Mannich bases. It was found that strong acids (HCl and CF₃COOH) have an activating action during the process. An ylide mechanism of the reaction was proposed from the data obtained.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 66–71, January, 1991.     

An axially symmetric contact problem for a half-space with an elastically reinforced cylindrical cavity

We consider the pressure of a plate on a half-space with a round cylindrical cavity. The surface of the cavity is reinforced by elastic elements that are modeled by very general operators. The problem is reduced to a Fredholm integral equation of second kind. A detailed study is made of the case of reinforcement described by the Winkler law. An approximate solution is obtained in the form of the asymptotics with respect to the radii of the plate and the cavity.Translated fromDinamicheskie Sistemy, No. 6, 1987, pp. 80–85.     

Similarity and the structure of unital matrix quadratic trinomials with pairwise different characteristic roots

The normal form of certain polynomial matrices is found.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova Akademii Nauk SSSR, Vol. 175, pp. 63–68, 1989.     

Neutron interferometry in gravitational field with torsion

We consider the possibility of finding experimental evidence of the fifth force with the measurement of a phase shift of neutron beams via an interferometric apparatus and also a possible rotation of the polarization plane of polarized neutron beams when torsion is introduced in a gravitational field.     

Symmetry character of collective states in 104Pd populated in the EC-β+ decay of 104Ag

The states of ¹⁰⁴Pd, populated in the EC-β⁺ decay of the ground ( J ^π = 5⁺) and metastable ( J ^π = 2⁺) states of ¹⁰⁴Ag, have been investigated in the framework of the proton-neutron interacting boson model, extending a previous analysis to take into account the newly appeared experimental data. All positive-parity states up to an excitation energy of 3 MeV and spin in the range J = 1-6, fed by more than 0.3% in the decay of the parent nucleus, have been considered. As a result, strong evidence has been found for interpreting most of these states as states of collective nature having a quite pure full- or mixed-symmetry character and, in particular, for identifying the 1⁺ level at 2276 keV as the lowest 1⁺ mixed-symmetry state.     

Illusions of vision: Interpretation within the framework of a holographic model

Several illusions of vision are considered on the basis of a neurophysiological holographic model of visual perception at the level of the eye’s and the retina. It is suggested that the eye’s optical system forms a spatial spectrum of the observed object rather than its image on the retina. The spectrum is encoded by active anisotropic quasi-crystalline structures of rod rhodopsins and cone iodopsins, and a complex Fourier hologram of the observed object consisting of two quadrature components is recorded. The holographic hypothesis is confirmed by the results obtained by digital simulation.     

Energy bounds of linked vortex states

Energy bounds of knotted and linked vortex states in a charged two-component system are considered. It is shown that a set of local minima of free energy contains new classes of universality. When the mutual linking number of vector order parameter of vortex lines is less than the Hopf invariant, these states have lower lying energies.     

Account of Thermal Flow Through Metal-Semimetal BiSb Contact Boundary for Determination of EHF Detector Volt-Watt Sensitivity

Bismuth, antimony and its alloys are the typical representatives of a class of semimetals, which electric conductance is lower in 10²-10³ times, than of usual well conducting an electrical current metals. The alloys bismuth with antimony have semi-conductor properties in wide area of compositions at temperatures below 77 °K. The semimetals are rather perspective materials from the point of view of their probable application in various devices [1,2,3].In present time the semimetal alloys BiSb have wide application in thermoelectric generators and refrigerators. In work [3] the opportunity of use of semimetals BiSb with percentage content of Bi and Sb from 8 % up to 25 % was shown as high-sensitivity and of small inertion indicators of the mm range radiation where thermoelectric effect is used. The principle of action of such indicators is based on occurrence of temperature gradient in a semimetal crystal BiSb that has two contacts of the various area with flowing electrical current. Basic element of such device is the dot contact metal - semimetal. One of the main characteristics is volt-watt sensitivity of metal-semimetal BiSb contact which calculating is shown in present work.