141 research outputs found
Cultura favorable hacia el uso de las Tecnologías de la Información y la Comunicación (TIC), en los estudiantes y docentes de la Escuela de Docencia Media Diversificada de la Facultad de Ciencias de la Educación
Compounds of magnesium, potassium, barium, and strontium chlorides with epsilon -caprolactam were prepared and studied by chemical and crystal-optical analyses, X-ray powder diffraction, and thermogravimetry. All of the compounds obtained were single-phase and crystallized in the monoclinic system. The final products of their thermolysis were MgO, CaCl2, SrCl2, and BaCl2, respectively
Choosing systems of ionic radii for crystal-chemical laws in lanthanide oxobromotungstates
The unit cell parameters in LnWO4Br compounds (Ln = La, Pr, Nd, Sm, Eu, Gd, Dy, Er, or Yb) are studied as functions of ionic radii in various systems. The best systems of ionic radii for the description of crystal-chemical laws in lanthanide oxobromotungstates are determined. Crystal-chemical plots are constructed for the unit cell parameters versus lanthanide ionic radius for the specified compounds, as well as the plot of the parameter c for the monoclinic crystal system that accounts for the monoclinic angle β. © 2008 Pleiades Publishing, Ltd
Choosing systems of ionic radii for crystal-chemical laws in lanthanide oxobromotungstates
The unit cell parameters in LnWO4Br compounds (Ln = La, Pr, Nd, Sm, Eu, Gd, Dy, Er, or Yb) are studied as functions of ionic radii in various systems. The best systems of ionic radii for the description of crystal-chemical laws in lanthanide oxobromotungstates are determined. Crystal-chemical plots are constructed for the unit cell parameters versus lanthanide ionic radius for the specified compounds, as well as the plot of the parameter c for the monoclinic crystal system that accounts for the monoclinic angle β. © 2008 Pleiades Publishing, Ltd
Crystal-chemical features of monoclinic lanthanide oxobromotungstates of composition LnWO4Br (Ln = Eu, Gd, Dy, Er, Yb)
The crystal-chemical properties of lanthanide oxobromotungstates of composition LnWO4Br (Ln = Eu, Gd, Dy, Er, Yb) are studied. The crystal system and space group for the oxobromotungstates are determined. The unit cell parameters are refined. The parameters a, b, c, and V of the LnWO 4Br compounds are studied as functions of the atomic number of the lanthanide. Analytical equations are derived to predict unit cell parameters for unsynthesized lanthanide oxobromotungstates of the class in question. © Pleiades Publishing, Inc., 2006
Crystal chemistry of orthorhombic lanthanide oxobromotungstates of composition LnWO4Br
The crystal-chemical properties of lanthanide oxobromotungstates of composition LnWO4Br(Ln = La, Pr, Nd, Sm) were studied: the crystal system and space group were determined, and the unit cell parameters were refined. The dependence of the unit cell parameters a, b, c, and V of the LnWO4Br compounds on the lanthanide atomic number was analyzed. The analytical equations derived make it possible to predict the unit cell parameters for lanthanide oxobromotungstates that have not been synthesized yet. © Pleiades Publishing, Inc., 2006
Interaction between Dysprosium Oxide and Molybdenum(IV) Oxide
Phase equilibriums in the Dy2O3-MoO2 system are investigated by the methods of X-ray phase analysis, DTA, and IR spectroscopy. Molybdates(IV) of composition Dy2Mo2O7-x and Dy2MoO5-y occur in the system. In addition, in the range of concentrations from 5 to 25 mol % Dy2O3 the phase X is formed, which coexists with MoO2 and Dy2Mo2O7. The lattice parameters of the revealed phases are calculated
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