Search

The article analyzes the change in Germany's foreign policy in the Arctic. The features of the main vectors are revealed: in the military-industrial, scientific and educational, international political directions. It is concluded that it is in Germany's interests to support a renewed Arctic Council with a very limited participation of Russia, to strengthen the capabilities of the fleet and industrial potential for the production of equipment in the "Arctic" version, to build alternative scientific contacts with Russia.

Using the example of a two-joint cardan shaft, a method is presented for analytically describing its kinematic characteristics based on the use of vector analysis, which the author has been successfully using for a long time in designing various lever mechanisms. The proposed vector analysis method is based on the spatial coordinate transformation method. In this method, to get a vector rotated in space, you must specify the source vector, the vector around which the rotation will be performed, the angle of rotation itself and if a new vector length is required. In the proposed vector analysis method for describing the kinematics of a two-joint cardan shaft, the coordinates of the points of the axes of the cardan shafts and the radius of the cross are the basic geometric data. The adequacy of the results of kinematic analysis by the vector method was tested in two ways. In the first case, the values obtained by the vector method for the coordinates of all the characteristic points of the two-joint cardan shaft were compared with the corresponding coordinates of the characteristic points of the identical parametric model built in the three-dimensional CAD package. In the second case, the angular velocities and accelerations of the shafts of the two-joint cardan shaft obtained by the vector method were compared with the analytical dependencies given in the well-known literature sources. As a result of all the checks, it was concluded that the proposed method of vector analysis of two-joint cardan shaft is absolutely adequate. The developed method of vector analysis of the kinematic characteristics of two-joint cardan shaft can be further used to find the vector-loads (forces and moments) acting in the cardan transmission elements in order to conduct subsequent strength calculations. The proposed vector analysis method of two-joint cardan shaft is universal and can be successfully applied to describe the kinematics not only of two-joint cardan shaft, but also for polycardan transmission of any complexity.

In this paper an assessment of air pollution in Krasnoyarsk for 2017–2019 is carried out based on the observations primary data of stationary posts for monitoring the state of air quality; the location of the posts with an indication of the development type is shown.

The enhancement of the resolution of pump-probe optical diagnostics for ultrafast processes by compressing the probe pulse duration using the CafCA approach [1] is considered on an example of the BISER soft-X-ray generation [2] with the J-KAREN-P laser [3].

This article compares trends in the industrial development of the monocities of the Russian Arctic to those in the development of Germany’s Ruhr industrial district. It has been shown that in terms...

In this paper, we present the electromagnetic launcher with capacitive power source of 4.8 MJ. Our installation allows studying of the projectile acceleration in railgun in two regimes: with a solid armature and with a plasma piston. The experiments with plasma piston were performed in the railgun with the length of barrel of 0.7-1.0 m and its inner diameter of 17-24 mm. The velocities of lexan projectiles with weight of 5-15 g were in a range of 2.5-3.5 km/s. The physical mechanisms that limit speed of throwing in railgun are discussed.

A mathematical model is proposed for longitudinal oscillations of a tackle used for salvaging sunken vessels to the sea surface. The numerical approximation of the obtained model along the tackle rope length is accomplished by means of the finite-difference method. To implement this method, the transformation of independent coordinates is introduced into the constant step mesh. The integration with respect to time is carried out by the Φ-Wilson method. To solve the nonlinear systems of algebraic equations, iteration methods are used. There are examples of calculations for the vessel separation from the seabed and salvage from 1655 m depth when using various methods of controlling the winch shaft moment. The area of winch moment and heaving motion amplitude values that provide vessel emergency-free separation from seabed are calculated. It is shown that, with accuracy sufficient for practical use, the rope system of the tackle can be replaced in some cases by a single equivalent rope. Moreover, the rope mass can be neglected if it is considerably less than the mass of the vessel being salvaged. It is emphasized that the selection of the control of the velocity of salvage depends to a large extent on winch operation peculiarities.

The access protocol and information exchange efficiency research results for the "Gonets" low earth orbit communication network are submitted.