Self-division of a pulse consisting of several light-field oscillations in a nonlinear medium with dispersion

The nonparaxial dynamics of light pulses consisting of several light-field oscillations in nonlinear media with dispersion is analyzed. It is shown that the self-action of these extremely short pulses can result in their self-division.     

Larmor spin precession and neutron optics

We consider the neutron-optical phenomena that emerge during the coherent interaction of a neutron with a sample when the neutron spin precesses in a magnetic field. As follows from general considerations, such an interaction gives rise to an extra precession phase, which is added to the Larmor precession phase. This phenomenon can be interpreted as a manifestation of the time delay due to a finite time of the neutron-sample interaction. The Larmor neutron spin precession with a constant frequency serves as a clock for measuring this time delay. We used such a clock to directly measure the difference between the neutron velocity in matter and its vacuum value. We also present the results of the first experiments in which Larmor clocks were used to measure the neutron tunneling time in the resonance of a quasi-bound state and the Bragg diffraction time. Prospects for further applications of the method are discussed.     

Adsorption sensitivity of Si-electrolyte and Si-porous-Si-electrolyte systems

The adsorption sensitivities of silicon-electrolyte and silicon-porous-silicon-electrolyte systems with respect to organic molecules of different types are compared. It is shown that an additional nanoporous layer on the silicon surface does not improve appreciably the adsorption sensitivity of the silicon-electrolyte system, but it does make it possible in principle to increase the selectivity of this system. Zh. Tekh. Fiz. 68, 118–121 (February 1998)     

Locking response in coupled phase systems

Some distinctive features of the locking response to a chaotic action are pointed out using the example of coupled phase systems of the delay type: a) the possibility of locking for any values of the parameters of the acting subsystem in the case of precise matching of the response-subsystem parameters; b) relatively low sensitivity to mismatching of the subsystem parameters; and c) mild loss of locking in a nonuniform chain of phase systems.Nizhny Novgorod State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 36, No. 8, pp. 811–814, August, 1993.     

The analysis of the precision of single shot 2λ-CARS temperature measurements in hydrogen

Received: 16 October 1996/Revised version: 17 March 1997     

Classification of Totally Geodesic Surfaces in the Manifold of Directions in Physical Space

The Grassmannian of bivectors over the pseudo-Euclidean Minkowski 4-space is considered and its two-dimensional totally geodesic submanifolds are classified. The family of such surfaces is described in the language of the affine geometry of three-space. Bibliography: 5 titles.     

Summation of Divergent Series and Ergodic Theorems

In this article questions on the possibility of sharpening classic ergodic theorems is considered. To sharpen these theorems the author uses methods of summation of divergent sequences and series. The main topic is connected with the individual ergodic Birkhoff–Khinchin theorem. The theorem is studied in connection with the Riesz and Voronoi summation methods. These methods are weaker than those of the Cesaro method of arithmetic means. It is shown that already for the Bernoulli transformation of the unit interval, meaningful problems arise. These problems are interesting in connection with the possibility of extension of the strong law of large numbers. The questions of suitable summation factors and of the solution of homological equations by means of divergent series is also discussed.     

Study of the process of formation of excited states of krypton atomic ions via electron-stimulated desorption of excited molecular ions

The processes of population of excited levels of a krypton atomic ion via electron-stimulated desorption are studied. The radiation yield per single exciting electron in the corresponding krypton spectral lines is measured by the optical time-of-flight mass spectrometric method. The efficiency of the processes studied is compared with that of electron-impact excitation of the same levels.     

Effect of flexoelectricity on the curvature elasticity of the membrane

The contribution of flexoelectricity to the curvature elastic modulus for a symmetric lipid bilayer is calculated. The cases of permitted and forbidden charge exchange between the electrolyte on both sides of the membrane are discussed. On the basis of a simplified model of the lipid bilayer, an estimate of the difference of the moduli corresponding to these two cases is made.