The polymerization thermokinetics of pyrrole in the presence of iron trichloride art studied by using a Calvet microcalorimoter. The apparent activation energy, the pre-exponential constant and reaction order of this ...The polymerization thermokinetics of pyrrole in the presence of iron trichloride art studied by using a Calvet microcalorimoter. The apparent activation energy, the pre-exponential constant and reaction order of this reaction in the temperature range of 25.2—37℃are 34.5 KJ·mol<sup>-1</sup>, 10<sup>2.74</sup>S<sup>-1</sup> and 1 respectively. The activation free-energies of this reaction at 25.2°, 30°and 37℃are 91.8, 92.9 and 94.2 KJ·mol<sup>-1</sup> respectively.展开更多
The differential scanning calorimetric (DSC)curves of the mitochondria isolated from two varieties of sporophyte cytoplasmic male sterile and their fertile lines of Yie Bai and Ma Xie type rice have been determined. T...The differential scanning calorimetric (DSC)curves of the mitochondria isolated from two varieties of sporophyte cytoplasmic male sterile and their fertile lines of Yie Bai and Ma Xie type rice have been determined. The curves show that the energy is released continuously as temperature rise to 70℃. Some thermodynamic and kinetic parameters of the energy release of the mitochondria have been obtained. The presented results showed that the mitochondria from cytoplasmic male sterile rice released more heat and they had higher energy barrier, less rate, and more complicated mechanism than that of their fertile lines in the energy release process.展开更多
Thermokinetics of the dismutation of superoxide anion (O ·- 2) catalyzed by superoxide dismutase (SOD), in which the decomposition of hydrogen peroxide catalyzed by catalase is utilized as a source of oxygen and ...Thermokinetics of the dismutation of superoxide anion (O ·- 2) catalyzed by superoxide dismutase (SOD), in which the decomposition of hydrogen peroxide catalyzed by catalase is utilized as a source of oxygen and the autoxidation of pyrogallol as a source of the substrate (O ·- 2), has been studied by microcalorimetry. The molar reaction enthalpies of the SOD reaction and the pyrogallol autoxidation have been measured as -160.1 and -218 kJ·mol -1, respectively, at 298.15 K and pH 7.0. A novel method for the determination of SOD activity, the microcalorimetric assay for SOD, has been proposed. The experimental results showed that SOD had no effect on both kinetic parameters and the mechanism for the pyrogallol autoxidation. This autoxidation followed the second_order reaction kinetics in the presence of limited oxygen (the first order with respect to both pyrogallol and O 2), and the second-order rate constants were determined at 298.15 K and pH 8.0 to be 1.25 and 1.30 L·mol -1·s -1 in the absence and presence of SOD, respectively. A possible mechanism for the autoxidation of pyrogallol inhibited by SOD was also suggested.展开更多
A double-parameter theoretical model for the conduction calorimeter, in which the delay of sensing has been considered, is suggested, and a simple method for the determination of the parameters of the model is propose...A double-parameter theoretical model for the conduction calorimeter, in which the delay of sensing has been considered, is suggested, and a simple method for the determination of the parameters of the model is proposed. The experimental results show that on the basis of this model, the phenomenon of thermogram maximum in thermogram reconstruction can be eliminated, and it can be applied to the thermokinetic investigations of faster thermal change processes.展开更多
文摘The polymerization thermokinetics of pyrrole in the presence of iron trichloride art studied by using a Calvet microcalorimoter. The apparent activation energy, the pre-exponential constant and reaction order of this reaction in the temperature range of 25.2—37℃are 34.5 KJ·mol<sup>-1</sup>, 10<sup>2.74</sup>S<sup>-1</sup> and 1 respectively. The activation free-energies of this reaction at 25.2°, 30°and 37℃are 91.8, 92.9 and 94.2 KJ·mol<sup>-1</sup> respectively.
文摘The differential scanning calorimetric (DSC)curves of the mitochondria isolated from two varieties of sporophyte cytoplasmic male sterile and their fertile lines of Yie Bai and Ma Xie type rice have been determined. The curves show that the energy is released continuously as temperature rise to 70℃. Some thermodynamic and kinetic parameters of the energy release of the mitochondria have been obtained. The presented results showed that the mitochondria from cytoplasmic male sterile rice released more heat and they had higher energy barrier, less rate, and more complicated mechanism than that of their fertile lines in the energy release process.
文摘Thermokinetics of the dismutation of superoxide anion (O ·- 2) catalyzed by superoxide dismutase (SOD), in which the decomposition of hydrogen peroxide catalyzed by catalase is utilized as a source of oxygen and the autoxidation of pyrogallol as a source of the substrate (O ·- 2), has been studied by microcalorimetry. The molar reaction enthalpies of the SOD reaction and the pyrogallol autoxidation have been measured as -160.1 and -218 kJ·mol -1, respectively, at 298.15 K and pH 7.0. A novel method for the determination of SOD activity, the microcalorimetric assay for SOD, has been proposed. The experimental results showed that SOD had no effect on both kinetic parameters and the mechanism for the pyrogallol autoxidation. This autoxidation followed the second_order reaction kinetics in the presence of limited oxygen (the first order with respect to both pyrogallol and O 2), and the second-order rate constants were determined at 298.15 K and pH 8.0 to be 1.25 and 1.30 L·mol -1·s -1 in the absence and presence of SOD, respectively. A possible mechanism for the autoxidation of pyrogallol inhibited by SOD was also suggested.
基金Project supported by the National Natural Science Foundation of China.
文摘A double-parameter theoretical model for the conduction calorimeter, in which the delay of sensing has been considered, is suggested, and a simple method for the determination of the parameters of the model is proposed. The experimental results show that on the basis of this model, the phenomenon of thermogram maximum in thermogram reconstruction can be eliminated, and it can be applied to the thermokinetic investigations of faster thermal change processes.
