Electronic structure and reactivity of N-cyclohexylthiophthaleviide,a vulcanization inhibitor

CNDO/2 has been applied to calculate reactivity indices for N-cyclohexylthiophthalimide CTP. A quantitative evaluation is provided for the interaction in an accelerator-sulfur-CTP system. Comparison with experiment indicates a parameter governing the inhibitive activity.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 31, No. 1, pp. 57–60, January–February, 1995.     

Wavelengths and transition probabilities for the nitrogen isoelectronic series

The energies of transitions of the type 1 s² 2 s² 2 p³-1 s² 2 s 2 p⁴-1 s² 2 p⁵ were computed for isoelectronic sequence of nitrogen. The account was taken of the Hartree-Fock and correlation energies in the first two-three orders of the perturbation theory and the relativistic corrections in terms of Breit operator. The computed values were compared with experimental results for the isoelectronic oxygen series. Sufficiently good agreement of the computed and experimental results for all isoelectronic sequence manifests rather fast convergence in the series of powers of 1/Z. The perturbation theory was employed in computing the transition probabilities of 1 s² 2 s² 2 p³-1 s² 2 s 2 p⁴-1 s² 2 p⁵. The data computed may be used in the identification of the coronal solar spectra and the spectra of high-temperature plasma obtained under the laboratory conditions.To conclude it is our pleasant duty to thank Drs. S. L.Mandel'shtam, L. A.Vainshtein, E. Ya.Kononov and K. N.Koshelev for useful discussions and interest to the present work.     

Effect of technological factors on the mechanical reliability of structures made from composites

Research on the effect of technological factors on the strength of reinforced-plastics structures is reviewed. Attention is concentrated on structures in the form of bodies of revolution fabricated by the winding technique. The influence of the winding parameters and the curing regime on the residual stresses is discussed. Data on the variation of the mechanical properties of the resin in the course of the curing process are examined. The contributions of chemical and thermal shrinkage to residual stress formation are compared. Methods of reducing the residual stresses are considered.Presented at the 2nd All-Union Conference on Polymer Mechanics, Riga, November 10–12, 1971.Moscow Power Engineering Institute. Translated from Mekhanika Polimerov, No. 3, pp. 529–540, May–June, 1972.     

Local buckling of compressed elements of layered viscoelastic material

The problem of local surface buckling of compressed elements of layered material is solved using the equations of the theory of multilayer plates [1, 2, 5]. The local buckling deformations are described by means of the solutions of differential-difference equations damping into the interior of the medium. The effect of compressive forces, buckling wavelength, and the elastic and viscoelastic constants of the material on the behavior of the deformations and on the thickness of the layer to which significant buckling extends is investigated. Numerical estimates are presented for the buckling parameters of compressed laminated-plastic elements.Moscow Power Engineering Institute. Translated from Mekhanika Polimerov, Vol. 4, No. 5, pp. 816–821, September–October, 1968.     

Structures of copper(II) complexes with dihydrobenzoxazine derivatives in chloroform

Copper(II) complexes CuL₂ (HL = 2-(2-hydroxyphenyl)-4,4-diphenyl-1,2-dihydro-4H-3,1-benzoxazine and 2-(2-hydroxy-5-nitrophenyl)-4,4-diphenyl-1,2-dihydro-4H-3,1-benzoxazine) in chloroform were studied by EPR and electronic absorption spectroscopy. It was found that the complexation involves the azomethine forms of the ligands, which are coordinated by the Cu atom through the phenol and azomethine fragments of both ligands. The electronic absorption spectra were decomposed into Gaussian components to determine the d-d transition energies. The parameters of the complexation were calculated in terms of the angular overlap model. The order of energy arrangement of the orbitals of the central atom was determined: $d_{x^2 - y^2 } \gg d_{xy} > d_{z^2 } > d_{xz} > d_{yz} $ .     

Synthesis of copper(II) coordination compounds with benzoxazine derivatives

Copper(II) complexes with 1,2-dihydro-4H-3,1-benzoxazine (HL) derivatives, CuLOH, were prepared by anodic electrosynthesis. The use of an amalgamated copper anode resulted in an increase in the electrosynthesis rate. It follows from the IR spectra of the products that the benzoxazine ring in the ligand molecule is opened upon complexation, while a six-membered chelate ring involving the oxygen atom of the deprotonated phenol group and the imine nitrogen atom is formed.     

Anisotropic magnetoresistance and anisotropic tunneling magnetoresistance due to quantum interference in ferromagnetic metal break junctions

We measure the low-temperature resistance of permalloy break junctions as a function of contact size and the magnetic field angle in applied fields large enough to saturate the magnetization. For both nanometer-scale metallic contacts and tunneling devices we observe large changes in resistance with the angle, as large as 25% in the tunneling regime. The pattern of magnetoresistance is sensitive to changes in bias on a scale of a few mV. We interpret the effect as a consequence of conductance fluctuations due to quantum interference.     

Analysis of the technological stresses in wound components made out of composites during the whole duration of the preparation process

Conclusions The application of a discrete winding scheme and the relationships of the theory of filtration consolidation and the theory of unstable viscoelastic media to the calculation of the technological stresses allows one to take account of the most important technological factors and to describe the overall process involved in the preparation of wound components from laminar composites. The power winding stage and the nonisothermal heat-treatment stage make the greatest contribution to the magnitude of the technological stresses.Translated from Mekhanika Kompozitnykh Materialov, No. 3, pp. 500–508, May–June, 1980.