The synthesis of manganese-zinc ferrite through the transformation of polynuclear coordination compounds

The authors analyse the possibility of obtaining manganese-zinc ferrite through the transformations of polynuclear coordination compounds (pcc), either in the solid state or in a reaction medium. Polynuclear coordination compound precursors with the general molecular formula: [Fe(II)_xFe(III)_y(Mn_0.5Zn_0.5)(C₂O₄)₂(OH)_y+2(H₂O)₂] with 0.2相似文献   

An efficient method for large scale configuration interaction calculations

An efficient method of handling large scale configuration interaction calculations is developed and applied to the H₂O molecule as a test case. The method, which is based upon matrix partitioning, is shown to be capable of calculating the ¹B₁ spectrum of H₂O to an accuracy level of 0.1 eV for each state with very moderate computational effort.     

An implicit heating programme to minimize the effect of the difference between the sample temperature and the programmed temperature

An implicit heating programme is suggested for minimization of the effect of the difference between the sample temperature and the programmed temperature in a thermoanalytical set-up.

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Zusammenfassung Es wird ein implizites Aufheizprogramm beschrieben, das den Einfluss des Unterschiedes zwischen Probentemperatur und programmierter Temperatur für die Probe minimalisiert.

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Thermal behaviour of CO2 laser-irradiated CeO2 doped with Yb2O3

Results concerning the thermal behaviour of Yb₂O₃-doped CeO₂ samples irradiated with CO₂ laser beams in continuous wave are presented.

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Zusammenfassung Es werden Ergebnisse einer Untersuchung des thermischen Verhaltens von CeO₂-Proben dargelegt, die mit CO₂-Laser bestraht wurden.

     

Reinigung des Wasserstoffgases zu analytischen Zwecken

Ohne Zusammenfassung     

Applicability of the Kissinger equation in thermal analysis

Pt/WO_x–ZrO₂ bifunctional catalysts were synthesized using impregnation and polymeric precursor methods. After the synthesis process the samples were calcined at 600, 700 and 800°C and characterized by X-ray diffraction, nitrogen adsorption and temperature programmed reduction study by thermogravimetry. DTG-TPR profiles showed between three and five reduction events at different temperatures attributed to platinum reduction and to different stages of tungsten species reduction. A comparative study of the synthesis method influence on the DTG-TPR curves was accomplished.     

Some problems concerning the evaluation of non-isothermal kinetic parameters

The validity of isoconversional methods used to evaluate the activation energy is discussed. The authors have shown that the Flynn-Wall-Ozawa and Friedman methods give results that agree with each other only if the activation energy does not change with the degree of conversion. A criterion for the reaction mechanism as expressed by the differential conversion function is suggested too.     

Reduction of 1-formyl-1,2,3,4-tetrahydroquinoline with ethyldiphenylsilane

Latvian Institute of Organic Synthesis, Riga LV-1006. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 424–425, March, 1995.Original article submitted February 14, 1995.