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31.
A. V. Mikhailov N. A. Gribchenkova E. N. Kolosov A. R. Kaul’ A. S. Alikhanyan 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2011,85(1):26-30
The thermodynamics of vaporization in the Bi2O3-Fe2O3 quasibinary system was studied by high-temperature mass-spectrometry. The partial pressures of the constituents of a saturated
vapor over the system at 1100 K were determined. Based on the experimental data, the following parameters were calculated:
the activities of the components of the Bi2O3-Fe2O3 system condensed phase, the standard enthalpies of some heterogeneous reactions, and standard enthalpies of formation and
enthalpies of formation for crystalline BiFeO3 and Bi2Fe4O9 from individual oxides. An optimal temperature for the solid-phase synthesis of bismuth ferrites from simple oxides is recommended. 相似文献
32.
Structures of the indole···pyridine dimer and (indole)2···pyridine trimer have been investigated in a supersonic jet using resonant two-photon ionization (R2PI) and IR-UV double resonance spectroscopic techniques combined with quantum chemistry calculations. R2PI spectra of the dimer and the trimer recorded by electronic excitation of the indole moiety show that the red-shift in the band origin of the dimer with respect to the 0(0)(0) band of the monomer is larger compared to that of the trimer. The presence of only one conformer in the case of both the dimer and the trimer has been confirmed from IR-UV hole-burning spectroscopy. The structures of the dimer and the trimer have been determined from resonant ion dip infrared (RIDIR) spectra combined with ab initio as well as DFT/M05-2X and DFT/M06-2X calculations. It has been found that the dimer, observed in the experiment, has a V-shaped geometry stabilized by N–H···N and C–H···N hydrogen bonding interactions, as well as C–H···π and π···π dispersion interactions. The geometry of the trimer has been found to be a cyclic one stabilized by N–H···N, N–H···π, C–H···π, and C–H···N interactions. The most important finding of this current study is the observation of the mixed dimer and trimer, which are stabilized by hydrogen bonding as well as dispersion interactions. 相似文献
33.
A. M. Balagurov I. A. Bobrikov V. Yu. Pomyakushin D. V. Sheptyakov N. A. Babushkina O. Yu. Gorbenko M. S. Kartavtseva A. R. Kaul’ 《JETP Letters》2005,82(9):594-598
Results of neutron diffraction studies of R0.5Sr0.5MnO3 manganites (R = Sm, Nd0.772Tb0.228, and Nd0.544Tb0.456) performed to reveal the microscopic origins of the giant oxygen isotope effect recently discovered in Sm0.5Sr0.5MnO3 are presented. It is shown that two crystalline phases differing in the type of Jahn-Teller distortions of oxygen octahedra and in the type of magnetic ordering coexist at low temperatures in all the studied compositions. A scenario for the observed phase transitions is suggested based on the diffraction data. It is found that the percolation transition from the metallic to insulating state in compositions with Sm upon substitution of 18O for 16O is associated with a sharp (from 65 to 13%) decrease in the volume of the ferromagnetic metallic phase. 相似文献
34.
M. Sauer C. Zander R. Müller B. Ullrich K.H. Drexhage S. Kaul J. Wolfrum 《Applied physics. B, Lasers and optics》1997,65(3):427-431
-11 M without separation steps.
Received: 25 July 1997 相似文献
35.
K. H. Althoff G. Anton B. Bock D. Bour W. Ferber H. W. Gelhausen T. Jahnen O. Kaul D. Menze W. Meyer T. Miczaika R. Müller E. Roderburg W. Ruhm E. Schilling W. J. Schwille D. Sundermann K. Wagener 《Zeitschrift fur Physik C Particles and Fields》1983,18(3):199-205
The differential cross section of the reactionγ+p→π + was measured at pion CM-angles of 20° and 30° for photon energies between 500 MeV and 1,400 MeV. The pions were detected in a magnetic spectrometer. By measuring each pion trajectory and by offline calculation of the initial pion parameters an energy resolution of about 2.5% FWHM was achieved. The results complete a set of data which were measured in recent years at the Bonn 2.5 GeV synchrotron. In comparison to photoproduction analyses two effects were revealed: The η cusp appears in the energy dependence of the cross section as a sharp drop atK γ=710 MeV. In the region of the third resonance the data show a greater enhancement than predicted by most of the analyses. 相似文献
36.
T. Aziz S. Ahmad H. Ahrar S. B. Beri V. S. Bhatia S. N. Ganguli S. K. Gupta V. K. Gupta A. Gurtu G. L. Kaul Manjit Kaur A. R. Khan S. Kumar P. K. Malhotra L. K. Mangotra I. S. Mittra Y. Prakash N. K. Rao M. Shafi M. Shyam G. Singh S. K. Tuli Aligharh Collaboration Bombay Collaboration Chandigarh Collaboration Jammu Collaboration Varanasi Collaboration 《Zeitschrift fur Physik C Particles and Fields》1985,27(3):325-328
37.
38.
Roman V. Shpanchenko Enrique E. Kaul Christoph Geibel Evgeny V. Antipov 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(10):i88-i90
The structure of dilead vanadium oxide bis(phosphate) contains corrugated layers formed by VO5 square pyramids oriented in opposite directions in a chessboard fashion. The pyramids are connected by tetrahedral PO4 groups. The layers are separated by the Pb atoms and isolated PO4 tetrahedra. 相似文献
39.
40.
K.H. Althoff H. Beckschulze R. Conrad J. DeWire H. Herr E. Hilger V. Kadansky O. Kaul D. Menze W. Meyer 《Nuclear Physics B》1975,96(3):497-508
At the Bonn 2.5 GeV electron synchrotron the first measurements of the target asymmetry for the reaction γ + n ↑ → π? + p have been performed. The negative pions were detected in a magnetic spectrometer at a constant pion c.m. angle of 40° and photon energies between 0.45 GeV and 2.0 GeV. Deuterated butanol was used as target material. The polarization of the deuterons was about 16%. The results show a significant difference from the previously measured π+ asymmetry. 相似文献