Microdisplacement and microvibration sensors based on semiconductor lasers

Conclusion The above analysis of a microvibration sensor based on a semiconductor laser has shown that in the optimal operating regime one can expect a detection ability of 10^–2 nm.It is preferable to record an optical signal (change of radiation power) than an optoelectronic one (change diode voltage).Several sensor variants were constructed: with an ILPN-202 commercial laser diode, with a laser cartridge, and with the LMF-1300 single-mode laser module. Since real sensors contain additional noise sources (pumping- and recording-system noise, fluctuations due to parasitic reflection, etc.), the sensitivity limit could not be reached. The detection ability ranges, depending on the scheme employed, from fraction of a nanometer to several nanometers, but is perfectly acceptable for many practical applications.Translation of Preprint No. 42 of the Lebedev Physics Institute, Academy of Sciences of the USSR, Moscow, 1991.     

Solid state analysis in mechanochemistry by high resolution 27Al solid state NMR spectroscopy

Modern solid state NMR techniques [one-dimensional magic angle spinning (MAS) and two-dimensional quadrupole nutation experiments with MAS] are applied for the characterization of mechanochemically activated inorganic powders such as hydrargillite [-Al(OH)₃] and pseudo-boehmite [synthetic -AlO(OH)]. The materials were activated in a vibration mill.     

Characterization of the determinant of a Laguerre matrix

A Toeplitz-like matrix has naturally occurred in the construction of iteration functions for finding zeroes of an analytic function. In this note, we study the properties of a Toeplitz-like matrix, and its relationship to the well known Toeplitz matrix involving normalized derivatives of an analytic function.     

Some remarks on the genericity of unique range sets for meromorphic functions

In this paper we relate the study of unique range sets for meromorphic functions (URSM) with the hyperbolic hypersurfaces and give some remarks on the genericity of unique range sets for meromorphic functions.     

Tunneling Splittings in the S0 and S1 States of the Benzoic Acid Dimer Determined by High‐Resolution UV Spectroscopy

Five different isotopologues of the benzoic acid dimer and a vibronic band located 57 cm^?1 above the electronic origin, which is assigned to the out‐of‐plane butterfly motion, are studied by rotationally resolved UV spectroscopy. From these measurements a ground‐state structure with C_2h symmetry is deduced, whereas the symmetry is lowered to C_s in the S₁ state. The increase in the center‐of‐mass distance between the two monomers that is found on electronic excitation indicates a decrease in hydrogen‐bond strength. The tunneling splittings in the S₀ and S₁ states are 1385.2±0.7 and 271.2±0.7 MHz, respectively, corresponding to an increase in barrier height by 7.2 % on electronic excitation.     

Optical bistable behavior of single-mode fabry-perot lasers with saturable absorber

The present paper is devoted to the optical bistable behavior of Gaussian inhomogeneously broadened single-mode Fabry-Perot lasers with saturable absorber (LSA) in both resonance and nonresonance. The system is described by rate equations based on the dual two-level model with allowance for spontaneous emission and spatial hole-burning. The conditions under which optical bistability (OB) occurs are clearly displayed in phase diagrams. The OB characteristics and stability behavior are investigated in connection with their dependence on the detuning and LSA parameters. Paper submitted by authors in English April 20, 1999.     

An application of Razumikhin theorem to exponential stability for linear non-autonomous systems with time-varying delay

In this work, in the light of the Razumikhin stability theorem combined with the Newton–Leibniz formula, a new delay-dependent exponential stability condition is first derived for linear non-autonomous time delay systems without using model transformation and bounding techniques on the derivative of the time-varying delay function. The condition is presented in terms of the solution of Riccati differential equations.     

Some remarks on the genericity of unique range sets for meromorphic functions

In this paper we relate the study of unique range sets for meromorphic functions (URSM) with the hyperbolic hypersurfaces and give some remarks on the genericity of unique range sets for meromorphic functions.

     

The influence of nickel ions on the buffer capacity of aqueous solutions of glycine

The influence of nickel ions on the buffer properties of solutions of glycine of various concentrations was studied. The trends observed were interpreted in terms of ionic equilibria in the systems under consideration. It was shown that the buffer properties of solutions could be predicted by analyzing the corresponding distribution diagrams.