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71.
72.
Peter Ashwin Jennifer Creaser Krasimira Tsaneva-Atanasova 《The European physical journal. Special topics》2018,227(10-11):1091-1100
We explore sequential escape behaviour of coupled bistable systems under the influence of stochastic perturbations. We consider transient escapes from a marginally stable “quiescent” equilibrium to a more stable “active” equilibrium. The presence of coupling introduces dependence between the escape processes: for diffusive coupling there is a strongly coupled limit (fast domino regime) where the escapes are strongly synchronised while for intermediate coupling (slow domino regime) without partially escaped stable states, there is still a delayed effect. These regimes can be associated with bifurcations of equilibria in the low-noise limit. In this paper, we consider a localized form of non-diffusive (i.e. pulse-like) coupling and find similar changes in the distribution of escape times with coupling strength. However, we find transition to a slow domino regime that is not associated with any bifurcations of equilibria. We show that this transition can be understood as a codimension-one saddle connection bifurcation for the low-noise limit. At transition, the most likely escape path from one attractor hits the escape saddle from the basin of another partially escaped attractor. After this bifurcation, we find increasing coefficient of variation of the subsequent escape times. 相似文献
73.
Bong Jae?Chung Kirk?McDermid Ashwin?VaidyaEmail author 《The European Physical Journal B - Condensed Matter and Complex Systems》2014,87(1):20
Optimality principles have long been popular in the natural sciences and enjoyed much successes in various applications. However these principles seem to be disparate, each applied in limited contexts and there are far too many of them causing some consternation among scientists and philosophers of science regarding the ad-hoc nature of the optimality arguments. In this paper, we discuss the Maximum entropy production (MaxEP) as a plausible over-arching principle to understand stable configurations in fluid mechanics and related problems. The MaxEP being based upon sound physical arguments and in the immutable laws of thermodynamics along with the fact that it has been successfully co-opted across disciplines makes it worthy of attention. We discuss various physical and metaphysical aspects of this principle and use it to analyze some model problems regarding patterns in particle sedimentation such as sedimentation of a particle in Newtonian and non-Newtonian fluids and stable deformation of a falling droplet. 相似文献
74.
Nb(2)O(5) as a new electron transport layer (ETL) was used for double junction polymer solar cells. The Nb(2)O(5) ETL was prepared by spin coating a Nb(2)O(5) sol-gel solution onto the active layer of the optical front subcell. The double junction devices using Nb(2)O(5) ETL exhibit an open circuit voltage (V(oc)) of 1.30 V, which is close to the sum of the s of the individual subcells. The current density-voltage (J-V) simulation showed that the double junction device performance using Nb(2)O(5) as ETL could be significantly increased by reducing the series resistance (R(se)) and matching the current densities of the individual subcells. 相似文献
75.
The temperature dependent longitudinal and transverse Mossbauer elastic scattering fraction (MESF) of 47% disordered PVF2 have been computed using anisotropic dynamical model valid for polymer of any degree of crystallinity. The calculated values
show a marked anisotropy between the longitudinal and transverse fractions which can be easily observed. 相似文献
76.
77.
The title compound has been synthesised via an alkylation, Wittig-Horner reaction sequence, Michael addition of several active methylene substrates with compound 1 has been carried out. 相似文献
78.
Whitney's theorem on 2-isomorphism characterizes the set of graphs having the same cycles as a given graph, where a cycle is regarded as a set of edges. In this paper, vertex 2-isomorphism is defined and used to prove a vertex analogue of Whitney's theorem. The main theorem states that two connected graphs have the same set of cycles, where a cycle is now regarded as a set of vertices, if and only if one can be obtained from the other by a sequence of simple operations. © 1992 John Wiley & Sons, Inc. 相似文献
79.
Israel V. Muthu Vijayan Enoch Meenakshisundaram Swaminathan 《Journal of inclusion phenomena and macrocyclic chemistry》2005,53(3):149-154
The absorption and fluorescence spectral characteristics of 2-aminodiphenylsulphone (2ADPS) have been investigated in the presence of β-cyclodextrin (β-CDx) in water. Dual emission is observed upon the complexation of 2ADPS in β-CDx. The stoichiometry of the host:guest inclusion complex is found to be 2:1. Steady state and time-resolved fluorescence spectral analysis support the formation of 2:1 complex between β-CDx and 2ADPS. The large enhancement in fluorescence intensity of twisted intramolecular charge transfer (TICT) band in aqueous β-CDx solution is due to the decrease in non-radiative processes. The ground and the excited state pKa values for the monocation-neutral equilibrium of 2ADPS in β-CDx are found to be different from the pKa values in aqueous solution. In the presence of β-CDx, 2ADPS is found to be less basic in the ground and the excited states. 相似文献
80.