Determining phenomenological rate coefficients from a time-dependent, multiple-well master equation: “species reduction” at high temperatures

2013 ◽  
Vol 15 (13) ◽  
pp. 4744 ◽  
Author(s):  
James A. Miller ◽  
Stephen J. Klippenstein
Keyword(s):  
Master Equation ◽  
High Temperatures ◽  
Time Dependent ◽  
Rate Coefficients

scholarly journals Obtaining effective rate coefficients to describe the decomposition kinetics of the corannulene oxyradical at high temperatures

2017 ◽  
Vol 19 (18) ◽  
pp. 11064-11074 ◽  
Author(s):  
Hongmiao Wang ◽  
Xiaoqing You ◽  
Mark A. Blitz ◽  
Michael J. Pilling ◽  
Struan H. Robertson
Keyword(s):  
High Temperature ◽  
Master Equation ◽  
High Temperatures ◽  
Effective Rate ◽  
Decomposition Kinetics ◽  
Rate Coefficients ◽  
High Temperature Kinetics ◽  
Kinetics Of

This work analyzes the effect of overlapping eigenvalues on the high-temperature kinetics of a large oxyradical based on master equation solutions.

Photoinduced Charge Transfer Dynamics in Carotenoid-Porphyrin-C60 Triad via the Linearized Semiclassical Nonequilibrium Fermi's Golden Rule

2020 ◽  
Author(s):  
Zhengqing Tong ◽  
Margaret S. Cheung ◽  
Barry D. Dunietz ◽  
Eitan Geva ◽  
Xiang Sun
Keyword(s):  
Charge Transfer ◽  
Golden Rule ◽  
Time Dependent ◽  
Rate Coefficients ◽  
Initial State ◽  
Photoinduced Charge Transfer ◽  
Transfer Rates ◽  
Fermi's Golden Rule ◽  
Photoinduced Charge ◽  
Fermi’S Golden Rule

The nonequilibrium Fermi’s golden rule (NE-FGR) describes the time-dependent rate coefficient for electronic transitions, when the nuclear degrees of freedom start out in a <i>nonequilibrium</i> state. In this letter, the linearized semiclassical (LSC) approximation of the NE-FGR is used to calculate the photoinduced charge transfer rates in the carotenoid-porphyrin-C<sub>60</sub> molecular triad dissolved in explicit tetrahydrofuran. The initial nonequilibrium state corresponds to impulsive photoexcitation from the equilibrated ground-state to the ππ* state, and the porphyrin-to-C<sub>60</sub> and the carotenoid-to-C<sub>60</sub> charge transfer rates are calculated. Our results show that accounting for the nonequilibrium nature of the initial state significantly enhances the transition rate of the porphyrin-to-C<sub>60</sub> CT process. We also derive the instantaneous Marcus theory (IMT) from LSC NE-FGR, which casts the CT rate coefficients in terms of a Marcus-like expression, with explicitly time-dependent reorganization energy and reaction free energy. IMT is found to reproduce the CT rates in the system under consideration remarkably well.

MODELLING NITROGEN PROCESSES IN SOIL: MATHEMATICAL DEVELOPMENT AND RELATIONSHIPS

1976 ◽  
Vol 56 (2) ◽  
pp. 71-78 ◽  
Author(s):  
D. R. CAMERON ◽  
C. G. KOWALENKO
Keyword(s):  
Time Dependent ◽  
Rate Coefficients ◽  
Nitrification Rate ◽  
Order Kinetic ◽  
Nitrogen Flow ◽  
First Order ◽  
Interaction Term ◽  
Flow Pathways ◽  
Adsorption Desorption ◽  
Temperature Water

A small subsystem model was developed to simulate the major nitrogen flow pathways in an unsaturated soil treated with ammonium sulphate. A nonlinear Freundlich equilibrium model and a Langmuir kinetic model were used to describe mathematically the adsorption–desorption of soluble NH4+ to the exchangeable and clay-fixed phases, respectively. Time dependent, microbial mediated first-order kinetic models were used to quantify the ammonification and nitrification processes. The subsystem model was then used as a research tool to derive ammonification and nitrification rate coefficients for a preceding incubation experiment conducted using different soil moisture contents and temperatures. The model yields reasonably good fits to the observed data. A subsequent regression analysis relating the coefficients to temperature and moisture pointed out the importance of the temperature–water content interaction term in quantifying microbial mediated processes.

scholarly journals Stepwise introduction of model complexity in a generalized master equation approach to time-dependent transport

2012 ◽  
Vol 61 (2-3) ◽  
pp. 305-316 ◽  
Author(s):  
V. Gudmundsson ◽  
O. Jonasson ◽  
Th. Arnold ◽  
C-S. Tang ◽  
H.-S. Goan ◽  
...  
Keyword(s):  
Master Equation ◽  
Time Dependent ◽  
Model Complexity ◽  
Equation Approach ◽  
Master Equation Approach ◽  
Dependent Transport ◽  
Generalized Master Equation

scholarly journals Equivalence between Redfield- and master-equation approaches for a time-dependent quantum system and coherence control

2011 ◽  
Vol 83 (6) ◽  
Author(s):  
D. O. Soares-Pinto ◽  
M. H. Y. Moussa ◽  
J. Maziero ◽  
E. R. deAzevedo ◽  
T. J. Bonagamba ◽  
...  
Keyword(s):  
Master Equation ◽  
Quantum System ◽  
Time Dependent

Complex kinetic systems with time-dependent rate coefficients

1989 ◽  
Vol 44 (3) ◽  
pp. 185-191 ◽  
Author(s):  
J.C. Andre ◽  
F. Baros ◽  
J.M.G. Martinho
Keyword(s):  
Time Dependent ◽  
Rate Coefficients ◽  
Dependent Rate

scholarly journals Time-dependent Markovian quantum master equation

2018 ◽  
Vol 98 (5) ◽  
Author(s):  
Roie Dann ◽  
Amikam Levy ◽  
Ronnie Kosloff
Keyword(s):  
Master Equation ◽  
Time Dependent ◽  
Quantum Master Equation
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