Formation of oxaphospholane derivatives during the condensation of phosphonic acid esters with formaldehyde

Conclusions The condensation of esters of 2,2-dicarbethoxy-2-cyano-2-carbethoxy-, and 2-acetyl-2-carbethoxyethylphosphonic acids with formaldehyde (paraform) proceeds with the formation of oxaphospholane derivatives.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1180–1181, May, 1970.     

Dispersion laws in a simple monoclinic lattice

Group-theory methods are used to analyze the dispersion laws near symmetric points of the Brillouin zone of simple monoclinic crystals.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 47–52, April, 1971.     

Dispersion laws in crystals with a simple tetragonal lattice

Using the methods of the theory of charged corepresentation, the laws of dispersion were studied in the vicinity of symmetry points in the Brillouin zone for class D_2d crystals which form the simple tetragonal lattice Γ_q. Possible variants from the dispersion laws were obtained by quadratic approximation of the parametric expansion of the wave-vector components, taking into consideration and neglecting spin-orbit coupling. The zero inclination points were determined.