Home – Home – Jornals – REPORTS OF RUSSIAN HIGHER EDUCATION ACADEMY OF SCIENCES 2013 number

We study the problem of integral geometry in a strip on a family of curves of spherical type with a given weight function. We prove a uniqueness theorem and obtain an explicit expression for the Fourier transform of the solution of considered problem of integral geometry in a class of smooth finite functions.

In the present article, the application of calculus of variations was based to investigate nano-objects properties. The equations for the order parameter calculations were obtained in the case of supported thin films. The order parameter calculations were carried out for the coherent thin film-support boundary. The cases when the substances of thin film and support have the second-order phase transition were considered. The comparison of coherent, semi-coherent, and non-coherent boundaries was performed.

A numerical method for solving general problem of optimal complete set related to the class of NP-hard problems of discrete programming with Boolean variables has been proposed. The method is based on procedures of linearization of the initial conditions, Lagrangian decomposition and iterative parametric analysis of sequences generated subproblems. It has been shown that the algorithm is effective and asymptotically accurate according to dimension of optimal complete set problems.

VEPP-4M is an electron-positron collider operating in the wide beam energy range from 0.9 GeV to 5.5 GeV. Since 2002 experiments on HEP are conducted at the collider with detector KEDR. Besides HEP, there are other scientific programs at the VEPP-4 accelerator complex including SR experiments, nuclear physics studies with internal gas target, CPT-theorem verification, accelerator physics experiments, etc. The paper discusses the recent results, present status and prospective plans of the facility.

The beam of negative hydrogen ions is injected into the tandem accelerator with vacuum insulation in order to obtain high-current proton beam. To accurately direct the beam into the accelerator the magnetic focusing lenses are used. In this paper it is described the design of the special beam detector mounted in front of the first accelerating electrode and intended to measure beam profile and the current density. The results of measurements of the dependence of the current density on the power of the magnetic focusing lenses are shown. The parameters of the beam resulting in the best agreement of calculation and experiment are specified. The optimum focusing mode to inject the negative hydrogen ions into the accelerator is determined.

In the Institute of Nuclear Physics SB RAS the epithermal neutron source is entered into operation based on the tandem – accelerator with vacuum isolation. There was evaluated the accelerating installation components of a x-ray field causing dark current and breakdowns in accelerating gaps. The experimental measurements were carried out and the study results of the doze capacity dynamics are submitted, depending on change of a dark current in tandem accelerating gaps. The design changes of installation for prevention of occurrence of powerful X-ray radiation are offered and realized. The carried research allows setting necessary parameters for designing medical installation on the basis of an accelerator-tandem with vacuum isolation with the purpose of realization in oncological clinics neutron-capture therapy of malignant tumors.

Mathematical modeling of the shoulder rod deflection under longitudinal impact upon a rigid obstacle is carried out. A brief derivation of the formula for calculation of the rod bending in case of eccentrical impact forces is given. The value of the critical compression load is calculated by Tymoshenko method. The rod deflection value with the eccentricity of the longitudinal load depending on the size of the initial speed is calculated.

Algorithm for rejection of out-of-band interference is proposed. The algorithm is based on formation of invariant statistics. These statistics are invariant to a group of additive transformations characterizing a priori uncertainty of the interference’s frequency. The rejection is implemented by subtracting a projection of an observed spectrum into an interference subspace. The performance of the algorithm is summarized.

The method of the rigid gear's teeth profiling for harmonic drive is presented. The standard roller chain is used as the flexible gear. The method worked out is based on the piecewise-arc approximation of the flexible gear deformation by the spatial motion of the axis of the chain's joint. The method allows to design harmonic chain drives with high output capability and reliability.

Method for solving systems of finite element equations arising in vector finite element method with field separation technique for modeling a three dimensional electromagnetic field induced by horizontal electrical line in marine medium is considered. The advantage of developed approach to solving finite element systems of linear algebraic equations arising in marine electrical survey is shown.

The problem of the absorbed dose distribution during the EB treatment by ELV accelerator is considered. The value of the absorbed dose is determined by the speed of scanning electron beam along the accelerator exit window (i.e. the movement across the conveyor). It is determined both by the shape of scanning current and by the geometry of scanning magnets. A simple way to improve the dose distribution near the edges of the extraction device of accelerator is suggested. It allows to provide the non-uniformity less 4 %.

The results of the influence of tooth components of a core on amplitudes of traction characteristics of the electromagnetic motor at an original volume are presented. The problem was solved by the finite-element magnetic field modulation. The preliminary estimation of the influence of tooth components arrangement is given.

The results of 3D-modeling of geoelectric fields for different sources of electromagnetic field employed in marine electrical prospecting technologies for the hydrocarbon deposit survey are presented.

The thermal processes of topological patterns formation by LCVD method with nanosecond and subnanosecond laser pulse duration are investigated. The temperature rate at irradiated spot on surface exert significant influence on resolving power of method, as described. An effect of nonlinear dependence of optical film’s absorption from it’s thickness on initial growth rate of film on transparent substrates is estimated.