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Thermochemically initiated radical copolymerization of a mixture of di(1-methacryloxy-3-chloropropoxy-2-)methylphosphonate (FOM-II) and 2-hydroxypropyl methacrylate in the bulk in the presence of 1–10 wt % dissolved polyvinyl butyral was studied. The process is characterized by two and more self-acceleration periods. This is associated with specific features of FOM-II polymerization transformations and with the presence of polyvinyl butyral macromolecules capable of association with methacrylic monomer molecules in the polymerizing system. [ABSTRACT FROM AUTHOR]

The possibility of using fluoroperoxides derived from polyfluorinated di- and tetracarbonyl compounds as vulcanizing agents for SKF-32 and SKF-260 fluororubbers was examined. The vulcanizates obtained are characterized by the tensile strength of up to 5.1 MPa and relative elongation at break of up to 130%. The resistance of the vulcanizates to H2SO4 and H2SO4–HNO3 mixture increases by a factor of approximately 1.5–2, and the resistance to toluene and acetic acid, by 20–30% relative to the vulcanizates obtained from the same rubbers using benzoyl peroxide or Peroxymon F40 as a vulcanizing agent. [ABSTRACT FROM AUTHOR]

The reactions of polyfluorinated di- and tetracarbonyl compounds with tert-butyl hydroperoxide proceeds at one or several carbonyl groups, depending on the ketone structure. The resulting peroxides are of interest as initiators of radical reactions. [ABSTRACT FROM AUTHOR]

Two modifications of a new mercury sulfohalide of Hg3S2Br2− x Clx ( x = 0.5) composition have been grown from the gas phase and explored by X-ray structural analysis. The compounds were obtained at an attempt to synthesize an analogue of the rare mineral arzakite Hg3S2(Br, Cl)2 (Br > Cl). The refinement of the crystalline structures of monoclinic (I) and cubic (II) phases (I: a = 17.824(4) Å, b = 9.238(2) Å, c = 10.269(2) Å, β = 115.69(1)°, V = 1523.8(5) Å3, space group C2/ m, Z = 8, R = 0.0513; II: a = 18.248(2) Å, V = 6076.4(12) Å3, space group Pm3¯ n, Z = 32, R = 0.038) has shown that they are polymorphous modifications of the compound of Hg3S2Br1.5Cl0.5 formula. The monoclinic modification I is isostractural to the synthetic compound α-Hg3S2Br2. Modification II is isostructural to synthetic β-Hg3S2Cl2. In both structures, each atom S has in its surrounding three atoms of Hg forming umbrella-type groups SHg3 with spaces Hg—S 2.366–2.430 Å and angles HgSHg 95.66–97.60°. SHg3-fragments are bound by Hg-apices with the formation of isolated cubic groups [Hg12S8]. Like that in other structures of mercury chalcohalides, the main role in structure-forming of the investigated compounds is played by atoms of halogens creating a cubic sublattice in which radicals Hg—S are arranged. [ABSTRACT FROM AUTHOR]

Single crystals of lanthanum polysulfide were grown under nearly equilibrium conditions according to the PSndash;T–x diagram of the LaS1.5–LaS2 system described in the literature, and quenched from a temperature of 820°C. The structure of these crystals was determined. Their compositions are LaS1.96(2) and LaS2.00(2). The crystals of both compositions belong to the rhombic Pnma space group with a slight variation in lattice parameters in the ranges a = 8.133–8.124Å, b = 16.345–16.334Å, and c = 4.128–4.131Å. The nonstoichiometric polysulfide LaS1.96 is treated as a spatially averaged, disordered individual phase. Arguments are given that these polysulfide phases have compositions intermediate between LaS1.5 and LaS2. [ABSTRACT FROM AUTHOR]

The 16-channel EEG records of 45 adolescents with schizophrenia and 39 healthy adolescents were subjected to statistical combinatorial analysis of 160 elementary EEG characteristics (6 spectral and 4 segmental EEG characteristics for a channel). Employing pattern recognition algorithm "Kora-n", a list of 37 combined EEG patterns was compiled. This list characterized with a minimal error the EEG of healthy adolescents in such a way that none of these characters featured the EEG of adolescents with schizophrenia. Analysis of this list of EEG characteristics suggests that the contrast between EEG of healthy and ill adolescents is the sharpest in the F4, Cz, T3 and O1 derivations. Compared to EEG samples of schizophrenic subjects, EEGs of healthy subjects exhibit lower levels of delta and theta activity mainly in the frontal and temporal regions of the cortex and higher level of alpha activity predominantly in the occipital region. Applicability of the list of EEG patterns for diagnostics of schizophrenia-type disorders of adolescents is discussed.

The EEG records of 39 healthy adolescents and 45 age-matched schizophrenic patients were analyzed. The broad-band EEG spectral analysis and segmental analysis of the alpha-activity revealed significant differences between the groups. Schizophrenics differed in a decreased spectral power for the alpha2 and betal frequency bands and increased power for the delta and theta bands. Also, in schizophrenic adolescents, quasi-stationary alpha-rhythm segments were longer, and within-segmental EEG amplitudes were higher than in the healthy subjects; the amplitude variability and the steepness of transitions between neighbor segments were increased. The results of the EEG segmental analysis suggest a disintegration of local cortical neuronal ensembles in schizophrenia.

Segmental structure of the alpha activity of human EEG was studied in the state of rest and during arithmetical task performance with mono- and binaural listening of task instruction and binaural listening of music. The amplitude, duration, amplitude variability and steepness of between-segment transitions were calculated as segmental characteristics. It was shown that all of these characteristics are sensitive to the cognitive tests but the degree of this sensitivity depends on the cortex area and type of the cognitive task. Most pronounced changes in the segmental characteristics were observed during arithmetic task with left-side instruction presentation and minimal changes were seen during binaural listening of music.

Phasic organisation of human EEG alpha activity was studied in a pilot investigation using a previously suggested EEG segmental analysis methodology. The EEG was recorded in three normal subjects under resting conditions. The segmentation procedure enabled effective identifying of the periods with different amplitude in alpha band and the short-term transitions between them. Mean intersegmental variability of amplitude envelope were computed for the eyes closed and eyes open EEG in each of 16 standard derivations. Analysis of segment amplitude distributions showed that the difference between the average alpha activity amplitude in these conditions were determined mainly by variations in the number of segments of different amplitude classes and not by a shift of the distribution or by change of its width. Distribution and quartile analysis of mean segment amplitudes provide evidence for possible functional heterogeneity of upper and middle subranges of the amplitude range.