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1.
Timofeeva M. N. Matrosova M. M. Reshetenko T. V. Avdeeva L. B. Paukshtis E. A. Budneva A. A. Chuvilin A. L. Likholobov V. A. 《Russian Chemical Bulletin》2002,51(2):243-248
Adsorption of H3PW12O40 from water and organic oxygen-containing solvents (AcOH, Me2CO, MeOH) by carbon mesoporous materials, viz., Sibunit and catalytic filamentous carbons (CFC), was studied. The amount of irreversibly sorbed heteropolyacid is 50—100 mg g–1 of support and decreases in the series of solvents: H2O > Me2CO > AcOH > MeOH. The adsorption capacity of CFC depends on the specific surface, total pore volume, and microstructure of the CFC fiber. 相似文献
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E. I. Matrosov D. I. Lobanov N. V. Matrosova M. I. Kabachnik A. N. Nesmeyanov 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3-4)
Abstract The crystalline phosphoranes have been obtained. IR-, UV- and NMR spectra of phosphoranes (Ia,b) and their interaction products with nitrogen bases have been investigated. It was determined that phosphoranes have structure (I) with pentacoordinate phosphorus and phenolic hydroxy group, while their products of interactions with nitrogen bases have the ionic structure (II) with hexacoordinate phosphorus (II). The X-ray difraction approves the structure (I) for phosphorane Ib. 相似文献
4.
V. E. Kisel A. E. Troshin N. A. Tolstik V. G. Shcherbitsky N. V. Kuleshov V. N. Matrosov T. A. Matrosova M. I. Kupchenko 《Applied physics. B, Lasers and optics》2005,80(4-5):471-473
We report the efficient continuous-wave (CW) and Q-switched laser operation of a diode-pumped Yb:YVO4 laser. A CW output power of 1 W with a slope efficiency of 59% with respect to absorbed pump power was demonstrated. Passively Q-switched with a Cr4+:YAG saturable absorber, a Yb:YVO4 laser with Raman conversion was demonstrated. Q-switched 18.7- J pulses with a pulse duration of 17 ns and a peak power up to 1 kW were obtained at 1018-nm fundamental wavelength and 3.6- J pulses with a pulse duration of 6 ns and a peak power of about 0.6 kW were obtained at 1119.5-nm first-Stokes wavelength.This revised version was published online in March 2005. In the previous version, the published online date was missing 相似文献
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Lagatsky AA Sarmani AR Brown CT Sibbett W Kisel VE Selivanov AG Denisov IA Troshin AE Yumashev KV Kuleshov NV Matrosov VN Matrosova TA Kupchenko MI 《Optics letters》2005,30(23):3234-3236
We report the first demonstration, to our knowledge, of soft-aperture Kerr-lens mode locking in a diode-pumped femtosecond Yb3+:YVO4 laser. Near-transform-limited pulses as short as 61 fs are generated around a center wavelength of 1050 nm with an output power of 54 mW and a pulse repetition frequency of 104.5 MHz. This is, to our knowledge, the shortest pulse generated directly from an Yb laser having a crystalline host material. The femtosecond operation has a mode-locking threshold at an absorbed pump power of 190 mW. The nonlinear refractive indexes of the Yb3+:YVO4 crystal have been measured to be 19 x 10(-16) cm2/W and 15 x 10(-16) cm2/W for the sigma and pi polarizations, respectively, at 1080 nm. 相似文献
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Kisel VE Troshin AE Tolstik NA Shcherbitsky VG Kuleshov NV Matrosov VN Matrosova TA Kupchenko MI 《Optics letters》2004,29(21):2491-2493
The growth, spectroscopic properties, and laser performance of Yb:YVO4 crystal with laser diode pumping are reported. A peak absorption cross section of 7.4 x 10(-20) cm2 at 985 nm, a radiative lifetime of 0.25 ms, and a stimulated-emission cross section of 1.25 x 10(-20) cm2 at 1008 nm for pi polarization were determined for the Yb3+ ions in YVO4. Continuous-wave laser action of Yb:YVO4 at 1020-1027 nm was demonstrated with an output power of 610 mW and a slope efficiency of 49%. 相似文献
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Y.V. Volk A.M. Malyarevich K.V. Yumashev V.N. Matrosov T.A. Matrosova M.I. Kupchenko 《Applied physics. B, Lasers and optics》2007,88(3):443-447
Anisotropy of the nonlinear absorption of Co2+ ions in MgAl2O4 single crystal at the wavelengths of 1.35 and 1.54 μm has been experimentally demonstrated. The experimental data are analyzed
in the framework of a phenomenological model when the Co2+ ions are described as three sets of linear dipoles oriented along the crystallographic axes. Ground-state and excited state
absorption cross-sections at 1.35 and 1.54 μm are evaluated to be σgsa=(4.0±0.3)×10-19, σesa=(3.6±0.4)×10-20 cm2 and σgsa=(5.1±0.3)×10-19, σesa=(4.6±0.4)×10-20 cm2, respectively.
PACS 42.55.Rz; 71.20.Be 相似文献
8.
Timofeeva M. N. Matrosova M. M. Maksimov G. M. Likholobov V. A. 《Kinetics and Catalysis》2001,42(6):785-790
The acid properties of heteropoly acids of the following three structure types were studied by conductometry in acetic acid: Keggin (H3PW12O40, H3PMo12O40, H4SiW12O40, H3PW11ThO39; and H5PW11XO40, where X(IV) = Ti or Zr), Dawson (-H6P2W18O62and -H6P2Mo18O62), and H6P2W21O71(H2O)3. These compounds are electrolytes that dissociate in only the first step of this solvent. The thermodynamic dissociation constants of the heteropoly acids were calculated by the Fuoss–Kraus method. The Hammett acidity functions H
0of the solutions of H5PW11XO40, H3PW12O40, H4SiW12O40, and H6P2W21O71(H2O)3in 85% acetic acid at 25°C were determined by the indicator method. All of the test heteropoly acids were found to be strong acids. 相似文献
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Timofeeva M. N. Matrosova M. M. Maksimov G. M. Likholobov V. A. Golovin A. V. Maksimovskaya R. I. Paukshtis E. A. 《Kinetics and Catalysis》2001,42(6):791-795
The esterification reaction of n-butanol with acetic acid ([BuOH] : [HOAc] = 1 : 15 mol/mol; 55°C, 5% H2O) was studied in the presence of tungsten heteropoly acids of the Keggin (H3PW12O40, H4SiW12O40, H5PW11TiO40, H5PW11ZrO40, and H3PW11ThO39) and Dawson structure (-H6P2W18O62, H6P2W21O71(H2O)3, H6As2W21O69(H2O), and H21B3W39O132). The reaction orders with respect to H6P2W21O71(H2O)3, H3PW12O40, and H6P2W18O69are equal to 0.78, 1.00, and 0.97, respectively. It was found that the reaction rate depends on the acidity, as well as on the structure and composition of heteropoly acids. The H21B3W39O132heteropoly acid is most active, whereas the Keggin-structure heteropoly acids exhibit the lowest activities. Of the Keggin structure heteropoly acids, H5PW11ZrO40exhibits the highest activity because of the presence of a Lewis acid site in its structure. 相似文献
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