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71.
Phase equilibrium measurements, correlations and predictions are presented for the binary systems (R,S)-1-phenylethanol/CO2 and vinyl acetate/CO2 and for the ternary system vinyl acetate/(R,S)-1-phenylethanol/CO2. Experiments for the ternary system were performed in the temperature range of 323–343 K and in the pressure range of 7–12 MPa, using a high pressure phase equilibrium apparatus with a high pressure visual variable volume cell. Phase compositions were determined by taking samples of each phase and analysing them by gas chromatography. Equilibrium data were correlated with the Peng–Robinson equation of state combined with the Mathias–Klotz–Prausnitz mixing rule. A good correlation of both phases behaviour was obtained with an average absolute deviation (AAD) of 6.80%. Predictions for the binary sub-systems and for the ternary system were performed using the Peng–Robinson and the Soave–Redlich–Kwong equation of state, with the predictive mixing rule MHV1. 相似文献
72.
S. A. Udra V. I. Mashchenko L. A. Kazarin V. I. Gerasimov 《Polymer Science Series A》2008,50(12):1233-1237
The effect of shear fields on the rate of physical gelation in semidilute solutions of ultra-high-molecular-weight polyacrylonitrile in propylene carbonate and on the structural features of the resulting gels has been studied. At 30–70°C in the uniform shear field, the induction period of gelation decreases from several hours to several seconds with an increase in the shear stress. The patterns of these dependences are rather close at shear stresses above 20 Pa, while significant differences are observed at these temperatures only at low shear stresses (below 15 Pa). Depending on the shear stress, two types of gelation can be distinguished at 70°C. At stresses below 15 Pa, the polymer phase emerging in the course of shear deformation is aligned along shear lines and the sample is macroscopically nonuniform. At higher shear stresses, the structure of the sample is uniform throughout its bulk. 相似文献
73.
B. Krylov G. Gerasimov A. Morozov A. Arnesen R. Hallin F. Heijkenskjold 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,8(2):227-239
The VUV spectrum of gaseous mixtures of krypton with a small amount of xenon added was investigated in the range 115-200 nm.
The mixtures were excited in a capillary DC discharge where the capillary could be cooled by using liquid nitrogen. The mixed
molecule band around the XeI resonance line at nm and the mixed molecule continuum to the long wavelength side from the line were analysed. The band around nm was identified as transitions between a weakly bound excited state and the weakly bound ground state of XeKr molecules.
When cooling the capillary wall, the appearance of the Xe2 continuum was observed. The effect is ascribed to energy transfer between molecular states as a consequence of radiation
trapping in the band around nm. The role of the mixed molecule in the formation of the VUV spectrum of the gas mixture is discussed and underlined.
Received 12 May 1999 and Received in final form 27 August 1999 相似文献
74.
A. Morozov B. Krylov G. Gerasimov R. Hallin A. Arnesen 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,11(3):379-385
The origins of spectral structures that appear close to the Xe resonance line at 146.96 nm in absorption spectra of Kr gas
with an admixture of Xe are discussed in this paper. It is shown that these structures can result from bound-bound and bound-free
transitions in the Xe-Kr molecule between the ground state and the 1(3P1) excited state, which both are weakly-bound. The depth of the excited state is estimated. An introduction of a hump on the
1(3P1) state internuclear potential is suggested.
Received 15 December 1999 and Received in final form 20 February 2000 相似文献
75.
An experimental study was made of VUV spectra of a gas-discharge krypton plasma with a xenon impurity. The mixture pressure, the xenon impurity concentration, and the current were varied in ranges of 40–1000 hPa, 0.001–1%, and 10–50 mA, respectively. The heteronuclear XeKr dimers were shown to play a crucial role in the quenching of excitation energy of krypton dimers. The mechanism of transformation of the energy of excited krypton dimers in a low-temperature plasma of a binary krypton-xenon mixture is discussed. 相似文献
76.
Yu. V. Kaletina E. G. Gerasimov V. A. Kazantsev A. Yu. Kaletin 《Physics of the Solid State》2017,59(10):2002-2007
Thermal expansion and structural and magnetic phase transitions in alloys of the Ni–Mn–Sn system have been investigated. The spontaneous martensitic transformation in Ni51–xMn36 + xSn13 (0 ≤ x ≤ 3) alloys is found to be accompanied by high jumps in the temperature dependences of the linear thermal expansion. The relative change in the linear sizes of these alloys at the martensitic transformation is ~1.5 × 10–3. There are no anomalies in the magnetic-ordering temperature range in the temperature dependences of the coefficient of linear thermal expansion. The differences in the behavior of linear thermal expansion at the martensitic transformation in Ni51–xMn36 + xSn13 (0 ≤ x ≤ 3) and Ni47Mn40Sn13(x = 4) alloys have been established. 相似文献
77.
78.
Cubic paramagnetic centers formed by Yb3+ impurity ions in fluorite-type crystals MeF2 (Me = Cd, Ca, Pb) have been investigated using electron paramagnetic resonance, magnetic circular dichroism, magnetic circular polarization of luminescence, Zeeman splitting of optical absorption and luminescence lines, and optical detection of electron paramagnetic resonance. The g factors of the 2Γ7 state in the excited multiplet 2 F 5/2 of Yb3+ ions in Me F2 crystals, the hyperfine interaction constant 171 A (171Yb) for the excited multiplet 2 F 5/2 in the CaF2 crystal, and the energies and symmetry properties of all energy levels of Yb3+ ions in MeF2 crystals are determined. The crystal-field parameters for the crystals under investigation are calculated. 相似文献
79.
S. V. Karpov I. L. Isaev A. P. Gavrilyuk V. S. Gerasimov A. S. Grachev 《Colloid Journal》2009,71(3):345-352
Regularities of the self-organization of bimodal ensembles of nanoparticles into crystalline structures in metal lyosols are studied by the Brownian dynamics method. Differences in the thicknesses of adsorption layers, van der Waals, elastic, and electrostatic interactions, and random and dissipative forces, as well as variations in interparticle electrostatic interactions due to electron tunneling are taken into account in the model. Pair potentials for polydisperse ensembles of particles are analyzed and the correlation between the pattern of potential curves and the type of forming structures is revealed. The possibility of the selective coagulation of particles with different sizes by virtue of dissimilar charging at the moment of their approach is demonstrated. The kinetics of this process is investigated. Specific features of the crystallization of bimodal sols are discussed using real gold organosols as examples. 相似文献
80.
N. V. Mushnikov E. G. Gerasimov V. S. Gaviko P. B. Terent’ev K. A. Yazovskikh A. N. Pirogov 《Physics of the Solid State》2018,60(6):1082-1089
The magnetic structures that form in La1–xRxMn2Si2 (R = Sm, Tb) layered compounds with various concentrations x have been determined by magnetic neutron diffraction and magnetic measurements, and the magnetic phase diagrams have been built. It is shown that the formation of the magnetic structures is dependent not only on exchange interactions, but also on the type of the magnetic anisotropy of a rare-earth atom. It is found that, in La1–xTbxMn2Si2 compounds with 0.2 < x < 0.5, the competition of the Tb–Mn and Mn–Mn interlayer exchange interactions and the existence of a strong uniaxial magnetic anisotropy in the Mn and Tb sublattices leads to the frustrated magnetic state and prevents the formation of the long-range magnetic order in the Tb sublattice. 相似文献