The question of optimal quantum - signal processing is analyzed. An ideal quasim easurement which improves the quality of the estimation algorithm is introduced. The optimality of one particular algorithm for estimating noncommuting quantities, based on the quasi - measurement is proven for the special quadratic-Gaussian case.
Show AbstractMutual synchronization of circuits containing up to five thyratron generators is investigated experimentally and theoretically. The mutual synchronization dom ain, amplitude distributions and the steady period of oscillations in the sync hronization band are calculated for two coupled generators. Comparison with experimental results is made.
Show AbstractA rapid Fourier transform algorithm is employed for determining the true contours of components of the Mandel'shtam - Brillouin triplet in hexadecane at 60°C It is shown that in the case when the width of the experimental contour and of the instrument function are close in magnitude, it is possible to calculate the true contour by imposing certain conditions on the spectrum of the sought function.
Show AbstractThe time and space-time correlation functions in a rough-bottom test tank were measured. Eulerian turbulence scales, subsequently used for determining space scales L calculated on the assumption of validity of the Taylor theorem, are obtained from one-point measurements of velocity fluctuations obtained by a hotwire anemometer array. The longitudinal dimensions of turbulent inhomogeneities at two levels were determined from two-point recordings.
Show AbstractVarious models of a fluctuating viscous sublayer are examined. Conditions for matching the average values for the viscous sublayer and external [free-stream] turbulence make it possible to relate the oscillatory period with characteristics of the fluid and the free-stream turbulence and to describe satisfactorily the average velocity distribution in the vicinity of the wall.
Show AbstractA device for measuring turbulent fluctuations in liquids is described. A pyroelectric transducer of TsTS-19 [lead zirconate-titanate] ceramic measures the temperature fluctuations induced by changes in flow velocity. The transducer effectiveness is improved by artificial heating. An elementary calculation Is presented of the output signal for the case of harmonic fluctuations.
Show AbstractIt is shown that the statistical model of a crystal allows the existence of various types of acoustic waves. Their physical characteristics are determined; the feasibility of experimental detection of the new wave type is discussed.
Show AbstractThe parametric nature of energy supply to subharmonic oscillations and its features are clarified using an example of the excitation of the third subharmonic in anonlinear electric circuit.
Show AbstractMatrix representation of cascade connections of quadripoles, some of the branches of which are open, is impossible, since multiplication of matrices with elements equal to infinity is undefined. The article presents a method of algebraic description of cascade connections of quadripoles which reduce to pairs of bipoles, the impedances of which can have any values, including also infinity as a particular case.
Show AbstractThe Popov frequency-response stability criterion is written in analytic form in terms of general formulas. The transformed Popov's equation is explored by the root-locus method. The stability is determined from the location of the principal points of the root-locus hodograph as a function of the independent parameters q and k.
Show AbstractThe secondary truncation technique is employed for obtaining approximate solutions of a system of truncated differential equations for a single-loop automatically biased parametric oscillator. Approximate analytic equations are obtained for describing the establishing of oscillations in a parametric oscillator with allowance for simultaneous action of three amplitude limiting mechanisms (without allowance for the response lag of the automatic biasing network). Some analytic calculations are compared with numerical calculations and with experimental results.
Show AbstractThe motion anc radiation of a charged particle in the field of a plane electromagnetic wave is investigated. The nature of the motion is found to depend on the initial conditions and on the magnitude of the wave intensity parameter.
Show AbstractThe quasi - classical expansion of the self-congruent potential and the free energy of the anharmonic crystal with many - particle Interaction in the Bogolyubov method is obtained. Quantum corrections proportional to $h^2$ and $h^4$ are calculated, lated.
Show AbstractThe limiting sensitivity of gravity-wave detectors with a capacity transducer is examined. Expressions are obtained for the transducer response to a sinusoidal signal and to fluctuations. Conditions for the detection of the regular signal on the background of fluctuations are examined and a new algorithm for signal extraction is suggested.
Show AbstractThe limiting fields generated by a magnetized beam in a decelerating system are estimated by the nonlinear kinetic equation technique. It is shown that large- amplitude waves can be attained only in systems with low phase velocity. The limiting values of the field potential and beam current are estimated.
Show Abstract
