The electrokinetic stability of washed normal human erythrocytes is discussed from the point of view of pH, ionic strength, and composition of the suspending medium. Many of the electrophoretic characteristics at low ionic strengths (sorbitol to maintain the tonicity), such as the isopotential points, are shown to arise principally from adsorption of hemolysate. The concept of electrokineticall...

The hypothesis that the C+ + NH3 → CH2N + H reaction contributes to an HNC/HCN abundance ratio greater than unity in dark interstellar clouds has been tested using ab initio quantum chemical techniques. The hypothesis is based on the argument that a significant fraction of the ion product is the metastable H2NC isomer of C2V geometry, rather than the linear HNCH+ structure, and that the metasta...

Multiple light-induced reversible metastable NO linkage isomers (PLIs) have been detected in the dinitrosyl compound [RuCl(NO)2(PPh3)2]BF4 by a combination of photocrystallographic and IR analysis. The IR signature of three PLI states has been clearly identified, with estimated populations of 59% (PLI-1), 8% (PLI-2) and 5% (PLI-3) for a total population of the metastable state of 72%. The struc...

We consider mass-constrained minimizers for a class of non-convex energy functionals involving double-well potentials. Based upon global convex lower bounds to the energy, we introduce a simple strategy to find sufficient conditions on a given critical point (metastable state) to be a global minimizer. We show that this strategy works well for the one exact and known metastable state: the const...

The problem of metastability for a stochastic dynamics with a parallel updating rule is addressed in the Freidlin–Wentzel regime, namely, finite volume, small magnetic field, and small temperature. The model is characterized by the existence of many fixed points and cyclic pairs of the zero temperature dynamics, in which the system can be trapped in its way to the stable phase. Our strategy is ...

We numerically simulate a thermalization process in an energy landscape with hierarchically organized metastable states. The initial configuration is chosen to have a large energy excess relative to the thermal equilibrium value at the running temperature. We show that the initial energy surplus is dissipated in a series of intermittent bursts, or quakes, whose rate decreases as the inverse of ...

We present a formalism to describe slowly decaying systems in the context of finite Markov chains obeying detailed balance. We show that phase space can be partitioned into approximately decoupled regions, in which one may introduce restricted Markov chains which are close to the original process but do not leave these regions. Within this context, we identify the conditions under which the dec...

We describe a set of experiments that investigate diffusion of barium 6s5d DJ metastable level and 6s S0 ground-state atoms through the noble gases: He, Ne, Ar, Kr, and Xe. The barium metastable levels were populated through optical pumping of the 6s S0→6s6p P 1 intercombination transition with a pulsed laser, followed by spontaneous or stimulated emission into the 6s5d D1,2 levels. Collisional...

A neural network which is capable of recalling without errors any set of linearly independent patterns is studied. The network is based on a Hamiltonian version of the model of Personnaz et al. The energy of a state of N (+1}neurons is the square of the Euclidean distance —in phase space— between the state and the linear subspace spanned by the patterns. This energy corresponds to nonlocal upda...

The overdamped motion of a Brownian particle in randomly switching piece-wise metastable linear potential shows noise enhanced stability (NES): the noise stabilizes the metastable system and the system remains in this state for a longer time than in the absence of white noise. The mean first passage time (MFPT) has a maximum at a finite value of white noise intensity. The analytical expression ...