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Dynamics complex mode

Crystals lack some of the dynamic complexity of solutions, but are still a challenging subject for theoretical modeling. Long-range order and forces in crystals cause their spectrum of vibrational frequencies to appear more like a continuum than a series of discrete modes. Reduced partition function ratios for a continuous vibrational spectrum can be calculated using an integral, rather than the hnite product used in Equation (3) (Kieffer 1982),... [Pg.76]

The statistical theories provide a relatively simple model of chemical reactions, as they bypass the complicated problem of detailed single-particle and quantum mechanical dynamics by introducing probabilistic assumptions. Their applicability is, however, connected with the collisional mechanism of the process in question, too. The statistical phase space theories, associated mostly with the work of Light (in Ref. 6) and Nikitin (see Ref. 17), contain the assumption of a long-lived complex formation and are thus best suited for the description of complex-mode processes. On the other hand, direct character of the process is an implicit dynamical assumption of the transition-state theory. [Pg.266]

The appearance of complex modes of oscillatory behaviour such as chaos or bursting is due to the presence, within the same system, of two instability-generating mechanisms. It is when each of these mechanisms acquires a comparable importance that their interaction gives rise to complex dynamic phenomena. The fact that simple periodic behaviour nevertheless remains the most common suggests that for a large choice of parameter values, the uncoupling of the two mechanisms allows one of them to be active while the other remains silent . [Pg.158]

The complexation mode stoichiometries, conformations, and dynamics The possibility of simultaneous formation of complexes with different stoichiometries must also be considered. Cooperative binding, a bi-molecular process, has been observed, as well as the uni-molecular process, producing a 1 1 complex in either a head-to-tail (HT), tail-to-tail (TT) or head-to-head (HH) state. Moreover, a study of the fluorescence decay of a number of aniUnonaphthalene sulfonates in the presence of CD supported the view that a 1 1 complex can be present in several slightly different conformations. There are, in fact, various conformations and orientations of reactants as well as varying mobilities in reactant-CD complexes. [Pg.92]

Though proteins are the real functional entities, their considerably higher degrees of complexity in dynamic action modes have limited and delayed our approaches. [Pg.433]

Shimizu, Y, Aydan, d. Ichikaw, Y. 1988. A model study on dynamic failure modes of discontinuous rock slopes. In CJf. Li L. Yang (eds.). Proceedings of the International Symposium on Engineering in Complex Rock Formations, Beijing, 3-7 November, 1986. Beijing Science Press. [Pg.598]

Coming back to limit cycle oscillations shown by systems of ordinary differential equations, this simple mode of motion still seems to deserve some more attention, especially in relation to its role as a basic functional unit from which various dynamical complexities arise. This seems to occur in at least two ways. As mentioned above, one may start with a simple oscillator, increase [x, and obtain complicated behaviors this forms, in fact, a modern topic. However, another implication of this dynamical unit should not be left unnoticed. We should know that a limit cycle oscillator is also an important component system in various self-organization phenomena and also in other forms of spatio-temporal complexity such as turbulence. In this book, particular emphasis will be placed on this second aspect of oscillator systems. This naturally leads to the notion of the many-body theory of limit cycle oscillators we let many oscillators contact each other to form a field , and ask what modes of self-organiza-tion are possible or under what conditions spatio-temporal chaos arises, etc. A representative class of such many-oscillator systems in theory and practical application is that of the fields of diffusion-coupled oscillators (possibly with suitable modifications), so that this type of system will primarily be considered in this book. [Pg.6]

AMBER is a set of computer programs that use molecular mechanics, molecular dynamics, normal mode analysis, and free energy calculations to simulate accurately the properties of complex molecules and their interactions, both in vacuo and in condensed phases. A detailed description of the history and current form of AMBER has recently been published, so this article will attempt to give an overview of the program and the features which distinguish it from related programs. [Pg.11]

An approximate method for the response variability calculation of dynamical systems with uncertain stiffness and damping ratio can be found in Papadimitriou et al. (1995). This approach is based on complex mode analysis where the variability of each mode is analyzed separately and can efficiently treat a variety of probability distributions assumed for the system parameters. A probability density evolution method (PDEM) has also been developed for the dynamic response analysis of linear stochastic structures (Li and Chen 2004). In this method, a probability density evolution equation (PDEE) is derived according to the principle of preservation of probability. With the state equation expression, the PDEE is further reduced to a one-dimensional partial differential equation from which the instantaneous probability density function (PDF) of the response and its evolution are obtained. Finally, variability response functions have been recently proposed as an alternative to direct MCS for the accurate and efficient computation of the dynamic response of linear structural systems with rmcertain Young modulus (Papadopoulos and Kokkinos 2012). [Pg.2241]

Hammes-Schiffer S 1998 Quantum dynamics of multiple modes for reactions in complex systems Feredey Discuss. Chem. Soc. 110 391... [Pg.2329]

Wheeler M D, Anderson D T, Todd M W, Lester M I, Krause O J and Clary D C 1999 Mode-selective decay dynamics of the ortho-Hj-OH complex experiment and theory Mol. Phys. 97 151-8... [Pg.2454]


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