Integral dependent on parameter E in classical non-isothermal kinetics with linear heating rate

A simple procedure to obtain the derivative of the temperature integral with respect to the activation energy is presented.     

Non-isothermal kinetics in mixtures of barium carbonate and titanium dioxide (anatase)

The complexes AgL (L = theobromine, 1,3,8-trimethylxanthine and 3,8-dimethylxanthine) Hg₂L·NO₃ (L = 3,8-dimethylxanthine and 1,3,8-trimethylxanthine) and Hg₂C₂(NO₃)₂ (C = caffeine), were prepared in aqueous and HNO₃ medium. These complexes were characterized by IR, ¹H-NMR, TG, DTG and DSC techniques.     

On the changes of the activation energy with the conversion degree in non-isothermal kinetics

The authors present their results concerning the changes of activation energy determined under non-isothermal conditions with the conversion degree. An interpretation of this effect is suggested.     

The thermal stability of two substituted thioamides

A derivatographic investigation was performed on the thermal behaviour of three thioamides and the nonisothermal kinetic parameters for the liquid-phase decomposition of N-acetylthiobenzamide were determined.     

Reentrant onset of chaos in tubular image states

We investigate the reentrant onset of chaos in "tubular image states," which are loosely bound states of electrons formed in the vicinity (20-40 nm) of conducting nanotubes. Chaos is shown to arise when an electron is placed in the vicinity of two metallic nanotubess with a magnetic field applied along the tubes. At stronger magnetic fields B approximately 10 T, we observe the formation of Landau-like states encircling the two-tube system, which wipe out the chaos. We can reinstall the chaos by charging oppositely the nanotubes, thus breaking the symmetry of the system and correspondingly the shape of the Landau-like states. Detailed analysis of the onset of chaos is done by studying the statistical properties of the eigenvalues spectrum and by investigating the spatial autocorrelation functions of individual eigenstates.     

Thermal decomposition kinetics of some aromatic azomonoethers

The non-isothermal kinetic parameters corresponding to the decomposition of 4-[(4-chlorobenzyl)oxy]-4’-nitro-azobenzene were evaluated. The kinetic analysis was performed by means of different multi-heating rates methods: isoconversional (‘model-free’) methods (Flynn–Wall–Ozawa) and invariant kinetic parameters method (IKP) associated with the criterion of the independence of activation parameters on the heating rate. The values of the obtained non-isothermal kinetic parameters are in satisfactory agreement.     

Simple and effective method for the synthesis of 3′,5′-substituted 1-β-D-arabinofuranosyluracil

3,5-Substituted arabinofuranosyluracil is a starting compound in 2-modifications. A convenient and effective method is proposed for the synthesis of 1-(3,5-di-o-trityl--D-arabinofuranosyl)uracil by successive reactions of 2,2-cyclization of uridine, 3,5-tritylation of the 2,2-anhydrouridine, and hydrolytic cleavage of the 2,2-anhydro bond.Institute of Organic Synthesis, Riga LV-1006. Odense Universitet, Kemisk Institut, Odense, Denmark. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 975–977, July, 1996. Original article submitted April 25, 1996.     

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.