The isolation of erysimoside from the seeds ofErysimum canescens

Chemistry of Natural Compounds -     

Analysis of erysimoside

Conclusions A method for the chromatophotocolorimetric determination of erysimoside in raw material is given which has been made the basis of the analytical control of its production.Order of the Red Banner of Labor Institute of the Chemistry of Plant Substances of the Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 334–336, May–June, 1974.     

Autoresonant asymptotics in an oscillating system with weak dissipation

We study a system of two first-order differential equations arising in averaging nonlinear systems over fast single-frequency oscillations. We consider the situation where the original system contains weak dissipative terms. We construct the asymptotic form of a two-parameter solution with an unbounded increasing amplitude. This result gives a key for understanding autoresonance in weak dissipative systems as a phenomenon of significant increase in the forced nonlinear oscillation initiated by a small external pumping. __________ Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 160, No. 1, pp. 102–111, July, 2009.     

Domain-wall mechanism of nucleation in a magnetic structural phase transition in La<Subscript>2</Subscript>CuO<Subscript>4</Subscript>

The structure of domain walls and new-phase nucleation are investigated in a four-sublattice antiferromagnet (AFM) of the La₂CuO₄ type placed in a magnetic field which initiates an AFM-weak-ferromagnet (WFM) magnetic structural phase transition. The critical fields for nucleus growth are found in the case of two types of domain walls present. The magnetization curve is calculated and a two-step mechanism is proposed for the AFM-WFM phase transition observed in La₂CuO₄.     

Structure and stationary dynamics of the interphase boundary in an La2CuO4 antiferromagnet

The structure of an interphase boundary is studied theoretically. The external magnetic field normal to the Cu-O layers at which an interphase boundary is formed in the La₂CuO₄-type four-sublattice antiferromagnet is determined. The effect of interplanar interactions on the structure of the interphase boundary is analyzed. The dependence of the stationary dynamics of this boundary on the external magnetic field is investigated.