The structure of liquid alcohols and the temperature dependence of vibrational bandwidth

To obtain the information about the structure peculiarities of liquid alcohols the temperature dependence of Raman profiles widths for these objects was studied. The results of these investigations have shown that in the region 150–340 K the widths of Raman bands in liquid methanol and ethanol are constant. From the data on the constancy of the number of hydrogen bonds per one molecule (in the same temperature range) the conclusion on the dynamic stability of the cluster structure of alcohols was made. The broadening of vibrational bands is determined by inhomogeneous broadening and by the dephasing of intramolecular vibrations due to the hydrogen bond dissociation.     

Fluorescent properties of pyrene-β-cyclodextrin inclusion complexes in titanium-silica sols

Fluorescence of pyrene-β-cyclodextrin inclusion complexes in silica and titanium-silica stable sols is studied. It is revealed that high fluorescence ability of pyrene in the aforementioned systems is retained due to the binding with β-cyclodextrin. The study of the influence of N,N-dimethylaniline on the fluorescence of complexes shows that, varying the ratio between cyclodextrin and molecules capable of penetrating into its hydrophobic cavity, one may both efficiently encapsulate these molecules or replace some of them with others in titanium-silica sols. Original Russian Text ? G.N. Starukh, A.M. Eremenko, N.P. Smirnova, A.A. Chuiko, A.V. Grigorovich, A.O. Doroshenko, 2006, published in Kolloidnyi Zhurnal, 2006, Vol. 68, No. 2, pp. 264–268.     

Thermodynamic characteristics of polyheteroarylene blends

The influence of the polybenzimidazole-to-polybismaleimide ratios and the chemical nature of sorbates on the thermodynamic characteristics of thermally structured blends of the polymers is studied. The optimum component ratio for the production of blends with good mechanical properties is found. The proton conductivity of the blends doped with phosphoric acid and acid zirconium phosphate is investigated.     

Magnetic properties of nanostructured samples of yttrium iron ferrite-garnet obtained by severe plastic deformation

The magnetic properties of nanoceramics of yttrium iron ferrite-garnet obtained by severe plastic deformation were investigated using the self-excited oscillator method. It is found that the coercive force and anisotropy field increase with an increase in strain and a decrease in the crystallite size.     

First results of millisecond pulsar 1937+21 timing by TNA-1500 radio telescope of Special Research Bureau of Moscow Power Engineering Institute

Regular timing observations of the millisecond pulsar PSR 1937+21 at a frequency of 610 MHz by means of the TNA-1500 radio telescope with a fully steerable 64-m antenna have begun at the Bear Lakes Radio Observatory of the Special Research Bureau of the Moscow Power Engineering Institute. A 40-channel spectrum analyzer and a system for high-speed recording and acquisition of observation data are connected to a reference clock by means of CAMAC interfaces and an 80286 control computer. The reception band is 1.6 MHz (40 channels of 40 kHz each). The total noise temperature of the system is on the order of 160 K. The signal-to-noise ratio is on the order of 50 for a 30-min observation of the pulsar. The mean-square error of measurement of the pulse arrival time is 400 nsec. Data on pulsar 1937+21 along with timing results for normal reference pulsars PSR 0834+06 and PSR 1919+21 obtained at the Pushino Radio Observatory of the Lebedev Physics Institute over a period of 13 years will be used to construct a pulsar time scale.Scientific-Research Radio-Physics Institute. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 37, No. 11, pp. 1388–1398, November, 1994.     

Acid–Base Properties of 3-Benzazolylcoumarins and Their Imino Analogs

The acid–base equilibria of 3-(N-methyl-2-benzimidazolyl)coumarins and imino chromenes were studied in aqueous ethanol. The major reason for the difference in their proton-acceptor capacity relative to their nonmethylated analogs lies in a loss of planarity of these molecules. The tautomerism of 7-hydroxy-2-iminochromene is discussed.     

Interfacing liquid chromatography with atmospheric pressure MALDI-MS

Two different strategies for coupling liquid chromatography with atmospheric pressure matrix assisted laser desorption/ionization (AP MALDI) are presented. The first method is flow-injection liquid AP UV-MALDI. Compared with previous similar research, the detection limit was improved 10 times to 8.3 fmol using a solution of 50 nM peptide with 25 mM α-cyano-4-hydroxycinnamic acid. The applicability of this method to measure oligosaccharides, actinomycin antibiotics, antibiotics, phosphopeptides, and proteins is demonstrated. The upper mass limit achieved with the current instrumentation is 6,500 Da (doubly charged cytochrome c). The feasibility of a second strategy based on single-droplet IR AP MALDI is demonstrated here. Aqueous peptide solutions were successfully measured by this method.