-Computer programs in FORTRAN 77 that calculate age spectra, Arrhenius plots, and log (r/ro) plots to manually model 4°Ar/39Ar diffusion data from multidomain samples are presented. Using these programs, one also can estimate the domain distribution parameters and cooling history (CH) by fitting the experimental data. The estimates are calculated iteratively starting from data obtained from the...

We perform molecular dynamics simulations to study the structural relaxation dynamics of a model of viscous silica, the prototype of a strong glass former. We find that the melt dynamics are spatially heterogeneous regardless of whether the bulk relaxation is non-Arrhenius or Arrhenius, and cannot be understood as a statistical bondbreaking process. Further, we show that stringlike motion is su...

The linear stability of a planar detonation wave with a three-step chain-branching reaction is studied by a normal mode approsch. The reaction model consists of a chain-initiation step and a chain-branching step governed by Arrhenius kinetics, with a chain-termination step which is independent of temperature. It mimics the essential reaction dynamics of a real chain-branching chemical system. T...

Many 4øAr/39Ar age spectra for alkali feldspars are significantly different from the model age spectra calculated for slowly cooled samples composed of diffusion domains of a single size, and the Arrhenius plots for these samples show departures from linearity that are inconsistent with diffusion from domains of equal size. The most plausible explanation for these discrepancies is the existence...

Arrhenius-type plots for multifragmentation process, defined as the transverse energy dependence of the single-fragment emission-probability, (ln(1/pb) vs 1/ √ Et), have been studied by examining the relationship of the parameters pb and Et to the intermediate-mass fragment multiplicity 〈n〉. The linearity of these plots reflects the correlation of the fragment multiplicity with the transverse e...

Arrhenius plots of fluoride- and guanine-nucleotide-stimulated adenylate cyclase activity were linear in adipocyte plasma membranes from lean and obese (ob/ob) mice. Arrhenius plots of isoprenaline-stimulated adenylate cyclase activity in hepatic plasma membranes biphasic in both groups. The results were biphasic in membranes from lean mice but linear in membranes from obese mice. In contrast, ...

The validity of the Arrhenius equation for dissociative electron attachment rate coefficients is investigated. A general analysis allows us to obtain estimates of the upper temperature bound for the range of validity of the Arrhenius equation in the endothermic case and both lower and upper bounds in the exothermic case with a reaction barrier. The results of the general discussion are illustra...