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631.
We demonstrate slow and stored light in Rb vapor with a combination of desirable features: minimal loss and distortion of the pulse shape, and large fractional delay (>10). This behavior is enabled by (i) a group index that can be controllably varied during light pulse propagation, and (ii) controllable gain integrated into the medium to compensate for pulse loss. Any medium with the above two characteristics should be able to realize similarly high-performance slow light. 相似文献
632.
Kulikova T. I. Zolotareva N. V. Novikova O. V. Semenov V. V. 《Russian Journal of General Chemistry》2021,91(12):2441-2446
Russian Journal of General Chemistry - The reaction of 3-aminopropyltriethoxysilane with (1-hydroxyethylidene)diphosphonic acid in 96% ethanol results in the 3-hydroxy(ethoxy)silylpropylaminium... 相似文献
633.
A. N. Egorochkin O. V. Kuznetsova O. V. Novikova 《Russian Journal of General Chemistry》2007,77(1):62-72
The first vertical electron affinities EA of 13 series of molecules and free radicals D(X i ) n are related to the inductive (σ I ), resonance (σ R ? ), and polarization (σα) parameters of substituents X i by the dependences EA = EA H + aΣσ I + bΣσ R/? + cΣσα: In radical anions D+·(X i ) n , compared to radical cations D+·(X i ) n , the polarization interaction is weaker or similar in magnitude but has an opposite sign. The previously unknown resonance parameters σ R ? of substituents SiMe3 and CH2SiMe3 bound to the radical anion center H2C=CH?· were calculated. 相似文献
634.
A. V. Ivanov A. S. Zaeva E. V. Novikova A. V. Gerasimenko W. Forsling 《Russian Journal of Coordination Chemistry》2007,33(4):233-243
Crystalline adducts of zinc and copper(II) dithiocarbamate complexes with dibutyl-and diisobutylamines of the general formula [M(NHR′2)(S2CNR2)2] (M = Zn, 63Cu, and 65Cu; R = CH3 and C2H5; R2 = (CH2)4O; R′ = C4H9 and i-C4H9) were synthesized. Their structures and spectroscopic properties were studied by EPR and solid-state natural abundance 13C and 15N CP/MAS NMR spectroscopy. Experimental EPR data and computer-assisted modeling confirmed the individual character of copper(II) adducts. The geometries of the copper coordination polyhedra were found to be intermediate between a tetragonal pyramid and a trigonal bipyramid (TBP). The contributions from TBP to the geometries of the adducts obtained were calculated from the EPR data. According to the X-ray diffraction data, the adduct of zinc diethyldithiocarbamate with diisobutylamine exists in two isomeric forms. The 13C and 15N CP/MAS NMR signals were assigned to the atomic positions in two crystallographically independent conformer molecules. 相似文献
635.
M. A. Kompanets O. V. Kushch E. V. Novikova A. G. Matvienko 《Theoretical and Experimental Chemistry》2011,47(4):232-237
A study was carried out on the effect of both the temperature of the reaction medium and structure of the initiator (N-hydroxyphthalimides)
on the tacticity of the polymethyl methacrylate obtained under radical polymerization conditions. An increase in the amount
of hydroxyl groups in the N-hydroxyphthalimide (NHPI) molecule leads to an increase in syndiotactic sequences in the macromolecule.
The Fordham equation was used to calculate the differences in the activation enthalpies and entropies for addition in the
iso and syndio positions in the presence of various N-hydroxyphthalimides. In all cases, formation of a syndiotactic polymer
is favored. 相似文献
636.
The role of carbon support morphology in the formation of catalytic layer of solid-polymer fuel cell
N. V. Smirnova A. B. Kuriganova K. S. Novikova E. V. Gerasimova 《Russian Journal of Electrochemistry》2014,50(9):899-903
The Pt/C catalysts with similar morphology of active catalytic phase (platinum nanoparticles), which were deposited on the supports with different types of carbon structures (Vulkan XC-72 carbon black, Taunit carbon tubes, and Timrex HSAG-300 carbon support with graphite structure), were fabricated by the method of electrochemical dispersion. The effect of the carbon structure type on the electrocatalytic properties of Pt/C catalysts was studied in their operation in the three-electrode cell and in-service in the membrane-electrode assembly of air-hydrogen solid-polymer fuel cell. The Pt/C catalyst based on the Vulkan XC-72 carbon support showed the best performance. The anisotropic shape of Taunit carbon nanotubes and the microstructure of Timrex HSAG-300 carbon support do not allow us to form a catalytic layer with a large active platinum surface area and a structure, which provides an effective ionic transport and mass exchange near the platinum surface. 相似文献
637.
L. M. Likhosherstov O. S. Novikova I. A. Yamskov V. E. Piskarev 《Russian Chemical Bulletin》2012,61(9):1816-1821
The action of ammonium carbamate in aqueous methanol in the presence of NH3 on three-, penta-, hexa-, octa-, and nonasaccharides of human milk and on decasaccharide (N-glycan from human immunoglobulin (IgG)) containing one or two a-l-fucose residues led to the corresponding β-glycopyranosylamines. After their N-acylation upon treatment with N-hydroxysuccinimide ester of N-Boc-glycine or N-Boc-glycine anhydride (Boc is the tert-butyloxycarbonyl) with subsequent removal of the Boc group, N-glycyl-β-glycopyranosylamines were obtained in up to 75% yield. 相似文献
638.
Novikova I Phillips DF Zibrov AS Walsworth RL Taichenachev AV Yudin VI 《Optics letters》2006,31(15):2353-2355
We report an experimental comparison of three-photon-absorption resonances (N-resonances) for the D1 and D2 optical transitions of thermal (87)Rb vapor. We find that the D2 N-resonance has better contrast, a broader linewidth, and a more symmetric line shape than the D1 N-resonance. Taken together, these factors imply superior performance for frequency standards operating on alkali D2 N-resonances, in contrast with coherent population trapping resonances, for which the D2 transition provides poorer frequency standard performance than the D1 transition. 相似文献
639.
Likhosherstov L. M. Novikova O. S. Kononov L. O. Sivaev I. B. Bregadze V. I. 《Russian Chemical Bulletin》2009,58(2):446-449
Five glycoconjugates were obtained from ortho-carboranylacetic acid and β-actosylamine or β-d-galactopyranosylamine derivatives with the terminal amino group in the spacer. The glycoconjugates have different lengths
of the spacer (9 to 15 atoms) and contain two or three βlactosylamine residues or one, two, or three β-d-galactopyranosylamine residues. 相似文献
640.
A. M. Egorov S. A. Matyukhova I. S. Kocherova A. A. Novikova A. V. Anisimov 《Russian Journal of General Chemistry》2009,79(3):444-452
Abstarct The reaction of nickel with benzyl bromide in DMF has been studied. The reaction intermediates were investigated by different
methods and the kinetic and thermodynamic parameters were determined. The reaction of benzyl bromide with nickel was shown
to occur on the metal surface by the Langmuir-Hinshelwood scheme, with the formation of benzyl radicals which are recombined
and isomerized in solution to form 1,2-diphenylethane and trace amounts of 4.4′-dimethylbiphenyl.
Original Russian Text ? A.M. Egorov, S.A. Matyukhova, I.S. Kocherova, A.A. Novikova, A.V. Anisimov, 2009, published in Zhurnal
Obshchei Khimii, 2009, Vol. 79, No. 3, pp. 455–463. 相似文献