Effect of photoheating of electrons on the properties of compensated semiconductors

It is shown that even a small contribution to the total density of the high-energy tail in the electron distribution during impurity photoexcitation can change noticeably such properties of a compensated semiconductor as its Hall mobility and, in particular, the capture coefficient at repulsing Coulomb centers.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 13–16, February, 1984.The author is grateful to V. L. Bonch-Bruevich for discussion.     

An experimental study of reducing narrowband noise of a slat using chevrons

A new concept of reducing the noise of a slat by applying a chevron form to the bottom edge is experimentally verified. The results of parametric studies are presented, which have been carried out on a small-scale model of a part of the wing (a scale of 1: 18) with deflected high-lift devices (the slat and the flap) in the landing configuration. As a result of acoustic measurements, a decrease (up to 4.5 dB) in narrowband noise for some chevron geometries is observed in comparison to a usual slat. The value of the decrease is a complex function of frequency, the wing and slat geometry, and the flow characteristics.     

Detection of recrystallized structure by means of automatic analysis of electron backscattered diffraction patterns

The possibility of applying the automatic analysis of electron backscattered diffraction (EBSD) patterns to reveal the recrystallized structure in the partially recrystallized material has been discussed. The analysis has been performed based on new experimental results. It has been shown that the EBSD method can be successfully used to investigate the recrystallization process.     

Effect of the substituent on the phosphorus atom on the reaction of aminophosphines with 1-alkylisatins

Depending on the substituent on the phosphorus(III) atom, reactions of tris(dialkylamino)phosphines, 2-diethylamino-1,3,2-benzodioxaphosphole, and benzene-1,4-diylbis(N,N,N′,N′-tetraethylphosphonous diamide) with 1-alkylisatins lead to the formation of isoindigo derivatives, spirophosphoranes, or spirooxiranes whose structure was determined by NMR spectroscopy and X-ray analysis.     

Synthesis of diterpenoid steviol derivative containing a posphorus-carbon bond on the basis of Pudovik reaction

Russian Journal of General Chemistry -     

Classes of Bianchi equations of third order

On the basis of determining equations written out in terms of Laplace invariants, some classes of Bianchi equations of third order similar to well-known classes of hyperbolic equations with two independent variables are singled out.     

An atypical easy reductive cleavage of the conjugated CC bond in 1,1′-disubstituted isoindigos under the action of aqueous hydrazine hydrate

The reaction of diverse symmetrically-substituted isoindigo derivatives with 80% aqueous hydrazine hydrate is described. The influence of the structure of the substituent on either oxindole or isatin-3-hydrazone formation is discussed.