Estimation of the power of the Chelyabinsk meteoroid blast from optical,seismic, and infrasonic observation data

The power of the Chelyabinsk meteoroid blast is estimated from model calculations and the results of optic, seismic, and infrasonic observations. The power of the blast has been determined as 1–3 kt of TNT.     

Construction and testing of the ALICE TRD chambers at LHE,JINR

The current status of construction and testing of Transition Radiation Detectors (TRD) for ALICE at LHE, JINR, is presented. The main purpose of this detector is electron identification at intensive pion background. The whole ALICE TRD system is comprised of 540 wire chambers of total sensitive area ∼750 m². Each chamber consists of drift and amplifying gaps and a radiator. One hundred such TRD chambers will be constructed at LHE, JINR. The text was submitted by the authors in English.     

Nucleophilic substitution of halogen in 4-halo derivatives of glutamic acid

Reactions of diastereomeric dialkyl N-phthaloyl-4-haloglutamates withpara-anisidine were studied at high pressure, and an additional confirmation of the exactS _N2 mechanism of the reactions was obtained. Quantitative parameters of the relative reactivity of the diastereomers were found in various solvents, which made it possible to perform the desired synthesis of products of diastereomeric substitution. kg]Key words kw]glutamic acid kw]diastereoselectivity kw]nucleophilic substitution kw]reaction rate constant kw]high pressure.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 583–585, March, 1996.     

Investigation of the depth distribution of impurities by charged-particle activation

A method is described for the quantitative determination of the distribution of impurities, utilizing charged particles. Experimental data obtained by activation with 7.5 MeV³He ions are reported on the distribution of oxygen in Ge and Nb samples.     

Specific Features of the Kinetics of Atoms in a Three-Dimensional Bichromatic Standing Wave

The three-dimensional kinetics of resonance atoms with the J = 0 J = 1 quantum transition in the weak field of mutually orthogonal bichromatic standing waves under conditions of manifestation of the effect of straightening of radiation forces is considered. It is demonstrated that the character of particle motion (induced by the straightened radiation forces) significantly depends on the relative phase difference of standing waves. In general, it is vortex in character and can suppress the process of localization of atoms in the small vicinity of straightened radiation force nodes even in the presence of a strong friction force. The target-oriented choice of phase relationships between the field components with mutually orthogonal polarization directions guarantees a solution of the problem of purely optical localization of atoms in the mode of vortex-free motion.     

Synthesis of 4-phenyl-3,4-dihydro-β-carboline

4-Phenyl-3,4-dihydro--carboline was prepared using the Bischler—Napieralski reaction on -phenyltryptamine.Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 486–487, November–December, 2004.This revised version was published online in April 2005 with a corrected cover date.     

Copolymerization of sulfolane-containing acrylamido sulfonic acid with acrylamide and acrylonitrile in water

Copolymerization of sodium 4-acrylamido-4-methyltetrahydro-1,1⁶-dioxothiophene-3-sulfonate with acrylamide and acrylonitrile in water was studied. It was found the copolymer composition is mainly determined by association of the monomeric species.Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 10, 2004, pp. 1684–1688.Original Russian Text Copyright © 2004 by Shirshin, Kazantsev, Igolkin, Krasnov, Sivokhin.     

Reactivity of the Hydroxy Groups in Melezitose and Their Selective Protection

The reactivity of melezitose hydroxy groups was studied by tritylation in pyridine with subsequent acetylation. After partial detritylation of the products, acetyl group transfer from position 4 to 6 was observed. The structure of the prepared melezitose derivatives was established on the basis of their IR, ¹H, ¹³C, and ¹H-¹H COSY NMR, and mass spectra (fast atom bombardment), as well as from the results of model calculations performed with the aid of SGI Indigo Molecule-Pattern-Work-Station software package (Biosym) where the potential energy function was approximated with the CVFF potential. The reactivity of primary hydroxy groups in melezitose was found to decrease in the following order: 6' > 6 6' > 1'.     

Chemical modification of plant alkaloids. 6. T-reactions of anabasine derivatives

T-reactions of anabasine derivatives were performed for the first time. Condensation of 5-nitro-2-[2-(3pyridyl)piperidino]benzaldehyde with 1,3-dimethylbarbituric acid formed an annelated tetrahydroquinoline system containing a spiropyrimidine moiety as the T-reaction product. Condensation of this same aldehyde with Meldrum’s acid was accompanied by recyclization that led to opening of the piperidine ring and closing of the tetrahydroquinolone system. A third version of the T-reaction that also led to opening of the piperidine ring but without recyclization was the condensation with dimedone.