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101.
102.
A technique for producing ZrO2 dioxide nanoparticles under the action of pulsed laser radiation is developed. By the methods of transmission electron microscopy and X-ray phase analysis, it is shown that the high-temperature cubic phase of ZrO2 is formed during laser ablation. The dependence of the size of ZrO2 dispersed particles on the laser radiation intensity is determined. A thermodynamic one-dimensional model of laser ablation of zirconium dioxide is analyzed. The results of analytical computations of ablation of ZrO2 particles are confirmed by experimental data. 相似文献
103.
Elif Kose Unver Simge Tarkuc Yasemin Arslan Udum Cihangir Tanyeli Levent Toppare 《Journal of polymer science. Part A, Polymer chemistry》2010,48(8):1714-1720
A comparative investigation was undertaken for the electrosynthesis and electrochemical properties of three different electroactive polymers having a conjugated core building block, dibenzo[a,c]phenazine. A series of monomers has been synthesized as regards to thiophene based units; thiophene, 3‐hexyl thiophene, and 3,4‐ethylenedioxythiophene. The effects of different donor substituents on the polymers' electrochemical properties were examined by cyclic voltammetry. Introducing highly electron‐donating (ethylene dioxy) group to the monomer enables solubility while also lowering the oxidation potential. The planarity of the monomer unit enhances π‐stacking and consequently lowering the Eg from 2.4 eV (PHTP) to 1.7 (PTBP). Cyclic voltammetry and spectroelectrochemical measurements revealed that 2,7‐bis(4‐hexylthiophen‐2‐yl)dibenzo[a,c]phenazine (HTP) and 2,7‐bis(2,3‐dihydrothieno[3,4‐b][1,4]dioxin‐5‐yl)dibenzo[a,c]phenazine (TBP) possessed electrochromic behavior. The colorimetry analysis revealed that while PTBP have a color change from red to blue, PHTP has yellow color at neutral state and blue color at oxidized state. Hence the presence of the phenazine derivative as the acceptor unit causes a red shift in the polymers' absorption to have a blue color. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1714–1720, 2010 相似文献
104.
O. A. Petrov E. L. Kuz’mina O. G. Helevina V. E. Maizlish 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2011,85(9):1578-1583
The acid-base interaction of octa(m-trifluoromethylphenyl)tetraazaporphin with pyridine, 2-methylpiridine, morpholine, benzylamine, piperidine, n-butylamine, diethylamine, tert-butylamine, and triethylamine in benzene was studied. It was found that intermolecular transfer of spatially screened NH-group
protons from octa(m-trifluoromethylphenyl)tetraazaporphin to morpholine, benzylamine, piperidine, n-butylamine, and tert-butylamine is characterized by unusually low values of rate constants. The effect of the structure of octa(m-trifluoromethylphenyl)tetraazaporphin, octa(n-bromophenyl)tetraazaporphin, octa(n-bromophenyl)tetraazaporphin, and octa(n-nitrophenyl)tetraazaporphin, and the nature of a base on the kinetic parameters of acid-base equilibrium is shown. A structure
for complexes with proton transfer of octaphenylsubstituted tetraazaporphirins is suggested. It is revealed that they are
subject to decomposition over time with the formation of low molecular colorless products. 相似文献
105.
The optical properties of suspensions are studied in a wide range of concentrations. An expression for the polarization operator is obtained taking into account the contributions of two-and three-particle correlations. The extinction length l and the transport length l* are calculated in terms of a model of hard spheres. A detailed comparison of the results of calculations with experimental data is performed. In calculations, the structure factor is determined in the Percus-Yevick approximation, while the form factor is taken into account in the Rayleigh-Gans approximation and in terms of the Mie theory. It is shown that taking into account the contribution of three-particle correlations improves the agreement of the theory with experiment. It is found that, in the range of high suspension concentrations, the optical parameters are more sensitive to the choice of the model for the structure factor than for the form factor. 相似文献
106.
E. V. Kuz’mina L. N. Khatuntseva V. V. Apyari S. G. Dmitrienko 《Moscow University Chemistry Bulletin》2007,62(2):85-88
The sorption of 1-naphthylamine (NA) as 4-nitrobenzeneazonaphthylamine was studied as function of phase contact time, aqueous acidity, 4-nitrophenyldiazonium tetrafluoroborate (NPD) concentration, and NA concentration. A highly efficient method for the sorption/photometric determination of NA was developed. 相似文献
107.
108.
T. V. Krachino M. V. Kuz’min M. V. Loginov M. A. Mittsev 《Physics of the Solid State》1997,39(9):1493-1497
The electronic properties and mechanisms of formation of Yb-Si(111) thin-film structures, produced by room-temperature deposition
of Yb atoms on the Si(111)7×7 surface are studied by Auger electron and LEED spectroscopy and the contact potential difference
method. A study is also made of the effect of heating to 800 K on the properties of these structures. The interface is shown
to form by the Stransky-Krastanov mechanism. Heating the Yb-Si(111) system is found to result in a very high (up to 1 eV)
increase of the work function for all Yb atom concentrations on the silicon surface. In the adsorption stage, this increase
is due to the growth of 2D ytterbium domains, which is accompanied by the formation of polarized domains from the silicon
surface atoms with dangling valence bonds. The dipoles are oriented in such a way that their formation reduces the total energy
of the Yb-Si(111) system and increases the work function. In the stage of silicide formation, the increase of the work function
under heating is ultimately due to the appearance of a layer of silicon atoms on the Yb-Si(111) surface.
Fiz. Tverd. Tela (St. Petersburg) 39, 1672–1678 (September 1997) 相似文献
109.
Dynamics of the spectral intensity oscillations that occur in the vertical plane because of the time variability of the medium along the propagation path is described. The errors arising in measuring the frequency shifts of the interference structure are considered. For low-frequency broadband signals received on a stationary propagation path, experimental data on the shifts of their frequency spectra due to the variation of the reception depth are presented. The number of interfering modes and their arrival directions in the vertical plane are estimated from the measured frequency shifts of the spectral intensity oscillation. 相似文献
110.
P. A. Apanasevich S. A. Batishche A. S. Grabchikov A. A. Kuz’muk V. A. Lisinetskii V. A. Orlovich G. A. Tatur R. V. Chulkov 《Journal of Applied Spectroscopy》2006,73(3):371-376
We have studied stimulated Raman (SRS) conversion to the first Stokes component of multimode (M2 = 8) radiation from a YAG:Nd laser with lasing wavelengths of 1.319 μm, 1.338 μm, and 1.357 μm in a barium nitrate crystal.
We have obtained pulses of converted radiation with energies up to 120 mJ. We have achieved conversion efficiencies greater
than 40% for each of the three Raman laser wavelengths of 1.530 μm, 1.556 μm, and 1.582 μm with divergence of the beams of
converted radiation close to the diffraction-limited value (M2 < 1.5).
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 3, pp. 330–334, May–June, 2006. 相似文献