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61.
A. M. Berezhkovskii Yu. A. Makhnovskii R. A. Suris 《Journal of statistical physics》1991,65(5-6):1025-1041
We review a novel approach to treating many-body effects in diffusion-limited kinetics. The derivation of the general expression for the survival probability of a Brownian particle in the presence of randomly distributed traps is given. The reduction of this expression to both the Smoluchowski solultion and the wellknown asymptotic behavior is demonstrated. It is shown that the Smoluchowski solution gives a lower bound for the particle survival probability. The correction to the Smoluchowski solution which takes into account the particle death slowdown in the initial process stage is described. The steady-state rate-constant concentration dependence and the reflection of many-body effects in it are discussed in detail. 相似文献
62.
We have studied the characteristic features of carbazole phosphorescence quenching by benzophenone in toluene at 77 K. We
have shown that the decrease in the relative phosphorescence intensity for carbazole (energy donor) by a greater factor than
we see for the relative change in its decay time is due to the fact that a change in the phosphorescence decay time occurs
only for carbazole molecules participating in triplet-triplet energy transfer, while the substantial decrease in the phosphorescence
intensity for carbazole with no change in the phosphorescence decay time is connected with quenching of its singlet states.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 4, pp. 554–556, July–August, 2006. 相似文献
63.
A. Borgschulte R. Gremaud S. de Man R.J. Westerwaal J.H. Rector B. Dam R. Griessen 《Applied Surface Science》2006,253(3):1417-1423
The optical properties, the switching kinetics and the lifetime of hydrogen switchable mirrors based on Mg-Ni alloys are determined with particular regard to the composition of the optically active metal-hydride layer in combination with the thickness of the catalytic capping layer. For this, a high-throughput experiment is introduced. The switching kinetics and the reversibility of switchable mirrors are strongly thickness dependent, though the details hinge on the fine structure of the clustered capping layer. Therefore, the kinetics is correlated with the surface structures of Pd on MgyNi1−y as investigated by scanning tunneling microscopy. The results are explained by the so-called strong metal-support interaction (SMSI) state, characterized by a complete encapsulation of the capping layer clusters by oxidized species originating from the support. The SMSI-effect is less important with increasing Pd-layer thickness, and is suppressed by a good wetting of the Pd-clusters on the optically active film. This explains the critical thickness for the catalyzed hydrogen uptake observed in many switchable mirror systems. Moreover, the degradation of the kinetics during cycling is found to depend on the Pd-layer thickness and on the gas environment. Only films, covered with at least 15 nm Pd, show small degradation caused by the SMSI-effect. The SMSI-effect is partly reversible: after changing the gas environment from hydrogen to oxygen, the oxide on the Pd-clusters can be partly removed. 相似文献
64.
T. A. Berger 《Journal of separation science》1989,12(2):96-100
A model for restrictor flow produces accurate predictions of flow that can be used to optimize restrictor design. The relative amplitudes of restrictor and other flows and their effect on efficiency are discussed. 相似文献
65.
A new method for the analysis of thermal desorption spectra is presented, based on the experimental peak maximum functions
for temperatureT
m(β) and pressureP
m(β) and a rigorous mathematical treatment. The resonant heating rate βr is determined, satisfyingT
m(βr)=T
r, whereT
r is the resonant temperature defined byA exp(−E
d/(RT
r))=1. Desorption energyE
d and frequency factorA can be determined simultaneously with relatively high robustness towards statistical experimental errors as demonstrated
by computer-simulated thermal desorption spectra. 相似文献
66.
The thermal dehydration of copper(II) acetate hydrate has been studied between 353 and 406 K, over a range of humidities.
The dehydration is controlled by nucleation-and-growth kinetics at low temperatures, with an activation energy of 154 kJ·mol−1, which changes to contracting-disc kinetics at higher temperatures with a lower activation energy of 76 kJ·mol−1. Frequency factors have also been derived; the value for the high temperature process is low (107s−1) and that for the low temperature step is high (1017s−1). Optical microscopy has been used to clarify the bulk kinetics; there is evidence for a reactive layer at the surface of
the decomposing solid.
In celebration of the 60th birthday of Dr Andrew K. Galwey 相似文献
67.
Z. D. Zivkovic 《Journal of Thermal Analysis and Calorimetry》1994,41(1):99-104
The results of comparative thermal analysis (TG-DTG-DTA-DSC) of the thermal decomposition of hexamminecobalt(III) chloride in air atmosphere are reported. The kinetics and mechanism of the thermal decomposition, the process enthalpy and the variation in specific thermal capacity of the solid product reaction with temperature were determined. 相似文献
68.
Simultaneous DSC-TG and DTA-TG were used to investigate the calatytic effect of the metal on the thermal decomposition of
a cellulose matrix containing small copper particles. The techniques were also used to demonstrate the effect of the metal
particles on the subsequent activation of the carbon matrix, a process which develops the pore structure necessary to expose
the metal particles to the gas phase. Temperature programmed desorption was used to study the initial mass loss found on activation.
To quantify the catalytic effect of the copper particles on the activation process an estimate was made of the activation
energy of the catalysed and uncatalysed reactions. The work gives valuable information on the processes involved in the preparation
of a new range of metal-carbon catalysts.
In celebration of the 60th birthday of Dr. Andrew K. Galwey 相似文献
69.
70.