Quantum-interference effects for gamma radiation under crossing-anticrossing conditions for nuclear levels in an RF field

A new approach to observing the effect of electromagnetically induced transparency in gamma optics is proposed. The propagation of a resonant photon in a ⁵⁷Fe magnetic medium in an applied rf field is considered for this purpose. It is shown that, under crossing-anticrossing conditions, a resonant rf field substantially changes the gamma-optical properties of the medium, which become dependent on the parameters of the field. This opens the possibility for exercising a coherent control of the photon group velocity and a controllable filtration of unpolarized gamma radiation in a sample.     

Vibrational control of crystal growth from liquid phase

Modeling and numerical simulations of the convective flows induced by the vibration of the monocrystal during crystal growth have been performed for two configurations simulating the Cz and FZ methods. This permitted to emphasize the role of different vibrational mechanisms in the formation of the average flows. It is shown that an appropriate combination of these mechanisms can be used to counteract the usual convective flows (buoyancy- and/or thermocapillary-driven) inherent to crystal growth processes from the liquid phase. While vibrational convection is rather complex due to these identified mechanisms, the new modeling used in the present paper opens up very promising perspectives to efficiently control heat and mass transfer during real industrial applications of crystal growth from the liquid phase.     

Ordinary electromagnetic waves in absorptive crystals

It is shown that “switching-on” of absorption in a continuum of the directions of propagation of ordinary electromagnetic waves in transparent triclinic crystals results in the “survival” of only a discrete number of these directions. The relationships for the angular coordinates of these directions are obtained in terms of the components of a complex permittivity tensor.     

The First Iminoamidophosphite Ligand: Synthesis and Complexation with Rhodium(I)

Optically active amidophosphite with the peripheral imino group (R)-(Et₂N)₂POCH₂CH(Et)N=CHPh is synthesized through one-stage phosphorylation of the corresponding imino alcohol. Its reaction with [Rh(CO)₂Cl]₂ (at P : Rh = 1) yields the mononuclear chelate [Rh(CO)(P^N)Cl]. Structures of the compounds are determined by IR, ³¹P, and ¹³C NMR spectroscopy, mass spectrometry, and polarimetry.     

Photochromism of nitro-substituted spironaphthooxazines in polymer films

The photochromic properties of nitro-substituted spironaphthooxazines in polymer matrices of different polarity were investigated and the quantum yields of photocoloration and parameters of the dark decolorization reaction, which is a disperse process, were determined. The features of the behavior of the nitro-substituted spironaphthooxazines are determined by the more efficient reaction of the photoinduced form with the medium, which is the consequence of stabilization of the bipolar structure of the molecule of the colored form.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 543—547, March, 1990.     

Electrochemical machining of metals: Fundamentals of electrochemical shaping

Basic problems of metal electrochemical shaping theory are considered. Exact and approxi1mate (quasi-steady-state, locally one-dimensional) methods for solving direct and inverse problems are analyzed. Experimental methods for improving the electrochemical shaping accuracy are considered.Translated from Elektrokhimiya, Vol. 40, No. 12, 2004, pp. 1438–1480.Original Russian Text Copyright © 2004 by Davydov, Volgin, Lyubimov.     

A first <Emphasis Type="Italic">P,N</Emphasis>-bidentate phosphite with a chiral ketimine fragment. Catalytic properties of its Rh<Superscript>I</Superscript> and Pd<Superscript>II</Superscript> complexes in comparison with those of phosphine analogs

A chiral P,N-bidentate aryl phosphite ligand containing peripheral (R)-(+)-camphor-derived ketimine and its rhodium(I) and palladium(II) chelate complexes were synthesized for the first time. These compounds were found to be suitable for asymmetric allylic substitution. The Pd-catalyzed sulfonylation of 1,3-diphenylallyl acetate with sodium p-toluenesulfinate gave the product in 73% ee; in the alkylation of the same substrate with dimethyl malonate, the ee was 94%. These ee values are higher than the enantioselectivity achieved with the known phosphine analogs.Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1942–1945, September, 2004.     

Anomalous relationship of the energy of the sequential ionization of molecular systems as a result of effective electron-electron attraction in molecules

Conditions were found, under which an anomalous relationship should be observed in the energies of sequential ionization of molecules ("anomalous" molecules) such that a subsequent potential (I_n+1) is less than the preceding potential (I_n). These conditions are a function of the electronic vibrational instability of molecules or their ions upon change in the number of electrons in the system. An interrelationship was found with the previously proposed concept of effective electron—electron attraction in molecular systems.Institute of Physiologically Active Compounds, Russian Academy of Sciences, 142432 Chernogolovka. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 3, pp. 738–741, March, 1992.     

Synthesis of new amidophosphite ligand and its application in Ir-catalyzed asymmetric hydrogenation of heterocyclic compounds

A new chiral amidophosphite ligand was synthesized and tested in the iridium-catalyzed hydrogenation of heterocyclic compounds. The enantioselectivity of hydrogenation of 2-methylquinoline considerably increases when piperidine hydrochloride is used as an additive. The hydrogenation reaction of 8-methyl-2,4,5,6-tetrahydro-1H-pyrazino[3,2,1-jk]carbazole by metal complex was conducted for the first time to prepare enantiomerically enriched antidepressant Pyrazidol.     

The use of hypercrosslinked polymer sorbents and composites based on them in the sorption of toxic and bad-smelling substances

Russian Chemical Bulletin - The sorption of cadaverine from the air on hypercrosslinked polystyrene sorbents was investigated. An available technique for the introduction of iron oxide into the...