Ni(II)-Schiff base/SBA-15: a nanostructure and reusable catalyst for one-pot three-component green synthesis of 3,4-dihydropyrano[3,2-c]chromene derivatives

Research on Chemical Intermediates - An efficient, rapid, and environmentally benign Ni(II)-Schiff base/SBA-15-catalyzed one-pot three-component cyclocondensation process was described via the...     

Synthesis of Acyl Derivatives of Prolyl-leucinamides

Russian Journal of Organic Chemistry - Synthetic routes to prolyl-leucinamide, N-benzyl(prolyl)leucinamide, and N-(prolyl-leucyl)morpholine were proposed. Treatment of these compounds with benzoyl...     

Problems of solubility of hydrolysis lignin

Interaction of hydrolysis lignin with polyacrylonitrile in water-dimethyl sulfoxide solution in the presence of an activator was studied, and the properties of the products were examined.     

Interlayer magnetic coupling interactions of two ferromagnetic layers by spin polarized tunneling

Magnetic interactions involving ferromagnetic layers separated by an insulating barrier have been studied experimentally on a fully epitaxial hard-soft magnetic tunnel junction: Fe/MgO/Fe/Co. For a barrier thickness below 1 nm, a clear antiferromagnetic interaction is observed. Moreover, when reducing the MgO thickness from 1 to 0.5 nm, the coupling strength increases up to J=-0.26 erg.cm(-2). This behavior, well fitted by theoretical models, provides an unambiguous signature of the interlayer exchange coupling by spin-polarized quantum tunneling.     

The influence of dimerization on the orientational phase transition in the C<Subscript>60</Subscript> fullerite

The influence of dimerization of a C₆₀ fullerite subjected to thermobaric treatment on the change in linear dimensions upon the orientational phase transition is investigated. It is demonstrated that the effects associated with the dimerization of fullerites substantially affect the thermal expansion coefficient only for samples synthesized under the conditions P_syn≥8 GPa and T_syn≥70°C (where P_syn and T_syn are the pressure and temperature of the synthesis, respectively). These effects bring about a smearing of the phase transition, a shift of the transition toward low temperatures, and a decrease in the volume jump.     

Electron Diffraction Analysis of the Fracture Zone of Fe–0.45C–17Mn–3Al Steel Subjected to Multicyclic Fatigue Tests

The methods of transmission electron microscopy are used to investigate the structure and phase content of Fe–0.45C–17Mn–3Al steel subjected to multicyclic fatigue tests to failure after intermediate electrostimulation. It is demonstrated that electrostimulation does not change the mechanism of steel failure. An increase in the operating life time of samples after electrostimulation in the intermediate test stage is connected with the hindered -martensitic transformation, the relaxation of stress concentrators, and the reduction of the volume fraction of the critical dislocation (network) substructure in which -martensite is mainly developed.     

Catalytic properties of V?Sb?O systems in acrolein oxidation

Catalytic properties of V-Sb-O systems in acrolein oxidation have been studied. It has been established that the changes in the activity and selectivity of the catalysts are due to the phase and chemical properties of the system.

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Investigation of the electrophysical and photoelectric properties of diffused layers of gallium arsenide obtained by compensation of copper

The distribution of the electrophysical and photoelectric properties of diffuse layers of p-GaAs obtained by doping copper using different diffusion modes is investigated. The properties of diffuse layers of p — n structures and volume specimens doped with copper over the whole depth are compared. The behavior of impurity centers is studied in these specimens and their effect on the electrophysical and photoelectric parameters of the material is investigated.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 95–100, October, 1977.In conclusion we thank I. V. Kamenskii for carrying out the experiments.