Magnetic suspectibility of chromium enriched Cr—Co—V and Cr—Fe—V alloys
Magnetic suspectibility of chromium enriched Cr—Co—V and Cr—Fe—V alloys
E.I. Kondorskii, Т.I. Коstinа, V.P. Medvedchikov
We investigated the magnetic susceptibility and thermal expansion of alloys of chromium with 1.4l atomic % of Co, chromium with 1.4l atomic % of Co plus 0.77 atomic % of V , and chromium with 0.34 atomic % of Fe plus 0.78, 1.08 and 1.63 atomic % of V over the 77 to 400°K temperature range. The fraction of magnetic susceptibility Δχ, due to addition of V , Fe and Co, is identified. Above the Neel temperature the behavior of Δχ(Т) obeys the Curie-Weiss law in all cases. Analysis of results shows that at low concentrations, atoms of V have a local magnetic moment ~ 1μ$_{{B}}$ in the Cr matrix.
Show AbstractSystem of electrodes for creation of uniform crossed electric fields
System of electrodes for creation of uniform crossed electric fields
A.A. Вelоv, S.P. Vanуukоv, N.V. Rusanov
A system of electrodes, making it possible to obtain homogeneous crossed electric fields in a limited space is described. Results of theoretical analysis of the structure of fields by the method of conformal transformations are presented.
Show AbstractOn the ultimate detection limits of thermal radiation detectors
On the ultimate detection limits of thermal radiation detectors
V.В. Braginskii, J. Buechner, Yu.I. Vorontsov
The instrumental limits of detectivity of dilatometric, semiconductor and superconducting bolometers are determined. It is shown that even at temperatures of the order of 4°K the Instrumental limits of dilatometric and superconducting bolometers may be lower than the potential limit, resulting from fluctuations in heat transfer between the heatsensing element and its surrounding medium. The instrumental limit of detectivity of semiconductor bolometers at low temperatures is higher than the potential. The level of noise temperature of amplifiers, allowing attaining the potential detectivity is determined.
Show AbstractSynchronization of strats frequency by the modulation of discharge current
Synchronization of strats frequency by the modulation of discharge current
P.S. Landa, N.A. Sukhotskova
The problem examines analytically the question of synchronization of a distributed self-oscillatory system by a small applied force, using as an illustration the synchronization of the striation frequency by modulation of the discharge current. An analytic expression of the dependence of the bandwidth of stration synchronization on the modulation amplitude of the discharge current, and making it possible to refine the form of dispersion parameters of the strations in the self excitation domain is obtained.
Show AbstractGauge fields of discrete symmetrie
Gauge fields of discrete symmetrie
G.A. Sardanashvili
The specific nature of calibration fields of discrete Abelian groups of symmetries, i.e., as fields with zero strength whose sources are topological features of coordinate space, is demonstrated.
Show AbstractRestortion of function on its moments in transfer theory
Restortion of function on its moments in transfer theory
B.Ya. Yurkov
The method for reconstructing a function on the basis of its moment, developed by Spencer in the theory of penetration of fast electrons into matter, is modified in the present paper in such a manner as to eliminate the arbitrariness in selecting the parameters of the approximating function, as well as in constructing the sought distribution. In the modified method the parameters of the approximating function are determined solely by the moments of the sought distribution and by requiring satisfaction of recurrent relationships between the moments of the approximating function. The sought distribution is represented by two (for the odd and the even distributions) infinite series of approximating functions. The terms of these series contain parameters which are found from two corresponding systems of nonlinear equations by the method of successive a pproximations, which makes it, in principle, possible to obtain a solution with any desired accuracy. In positive direction of motion of the penetrating electrons the results of this paper are very close to those calculated by Spencer, whereas in the opposite direction they diverge perceptibly.
Show AbstractGeneral dynamic properties of some systems of third order
General dynamic properties of some systems of third order
G.A. Bendrikov, V.I. Miftakhov
A family of root loci of systems with characteristic equation $(p^3 + a_{1}p^{2}+a_{2}p+a_{3})+K(p+b_{1})=0$. is investigated. The types of root loci are determined and expressions are obtained for finding the form of the root locus from coefficients of this equation, without directly constructing the locus. A graphic geometric interpretation of variations of the types of root loci as a function of any system parameters is given. Common dynamic properties of such systems, allowing a more purposeful synthesis of the latter, are pointed out.
Show AbstractMultifrequency nonautonomic - regimes of autogenerator
Multifrequency nonautonomic - regimes of autogenerator
V.V. Кarpоv, I.I. Minakоva
The spectral relationships of the many - frequency synchronous mode of a self - sustained oscillatory upon many - frequency forcing at the principal tone are explored numerically by computer. The dependence of the amplitudes of the spectral components on the mistuning of frequencies of external forces for oscillators with a soft and rigid limit cycle is analyzed. It is shown that the behavior of the nonself sustained oscillator in the rigid limit cycle is primarily controlled by combinatorial interactions. Experiments performed with different units over the rf range rather satisfactorily confirm the analytic results.
Show AbstractStress field of glide dislocation loopsensemble
Stress field of glide dislocation loopsensemble
V.V. Вlagоveshchenskii, G.M. Zinenkova, N.A. Tyapunina, N.I. Shal'nova
Expressions for all the components of the elastic stress field of a dislocation glide loop are obtained in the continual isotropic approximation, in a form suitable for computer calculation. The stress fields of a chain of dislocation glide loops are calculated. Analysis shows that the field is significantly inhomogeneous and that, in order to obtain complete information on the field structure of an infinite chain it suffices to consider the field of five loops.
Show AbstractInfluence of steady medium flow on acoustical properties of multi-modes expansion chambers
Influence of steady medium flow on acoustical properties of multi-modes expansion chambers
P.N. Kravchun, К.V. Chernyshev
А multimode expansion chamber, filled with a moving ideal fluid, is examined. It is shown that the presence of the flow results in the appearance of the real part of the impedance matrix; here the active resistance is different for modes of different order. The flow-filled chamber is regarded as a nonmutual quadripole. Frequency curves of the levels of sound damping by the chamber at different flow velocities.
Show Abstract