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Lower bound method characterized

The numerical efficiency of the viscosity lower bound method has allowed calculations on considerably longer chains. The long chain Hmit results for 12-arm stars without intramolecular interactions and with EV (up to 325 beads) and in the theta region (up to 145 beads) [164] are close to the previous estimates with shorter chains (the extrapolated ratio g obtained in this study is also included in Table 4). The lower bound method has also served to characterize globule-coil transitions of 12-arm star chains from intrinsic viscosity calculations [143], though finite size effects are considerably more important than in the characterization of this transition from the radius of gyration data (see Fig. 17). This is due to the noticeable increase in the solvent permeabiHty associated with the chain expansion in better solvent conditions. However, the permeability effects are smaller in the more compact star chains than in their linear counterparts. [Pg.90]

Numerous experimental studies have been pubUshed on Au+-ligand compounds Wilkins and coworkers reported lower bounds for bond energies for a number ol complexes, derived from gas-phase reactions of Au+ with a series of organic compounds. Schrikler and coworkers applied a similar technique to determine and characterize the Au—F bond energy. A more detailed work deaUng with ligand exchange reactions used ion cyclotron resonance mass spectrometry as an analytical method to provide... [Pg.3]

Lack of space prevents us from describing in any detail other properties of pods. It should be mentioned though that pods may be characterized as repulsive or attractive according to the local behaviour of trajectories in their vicinity. Loosely speaking, repulsive pods repel trajectories in their vicinity, attractive pods attract them. These properties have enabled the development of a lower bound to the classical reaction probability, the construction of a new theory of direct reactions as well as new numerical methods for computation of classical product state distributions.The repulsive attractive properties provide a global picture of the classical flow of trajectories at a given energy. [Pg.144]

Given prior information in terms of a lower and upper bound, a prior bias, and constraints in terms of measured data, the MRE provides exact expressions for the posterior pdf and expected value of the inverse problem. The plume source is also characterized by a pdf The problem solved in their study is the same as Skaggs and Kabala s problem. For the noise-free data, MRE was able to reconstruct the plume evolution history indistinguishable from the true history. As for data with noise, the MRE method managed to recover the salient features of the source history. Another advantage using the MRE approach is that once the plume source history is reconstructed, future behavior of the plume can be easily predicted due to the probabilistic framework of MRE. Woodbury et al. [71] extended the MRE approach to reconstruct a 3D plume source within a ID constant velocity field and constant dispersivity system. [Pg.87]

On the other hand, molecular crystals are characterized by the existence of strongly bound (Frenkel type) excitons, and it has been shown that the lower-energy part of the absorption spectrum (say, the first 2 eV) is completely dominated by these excitons [168], even to the extent that the absorption corresponding to electron-hole pair generation is completely hidden in the exciton spectrum [128] and is revealed only by such methods as modulated electrorefletance [169]. The only states in the exciton bands that are accessible by photon absorption are those at the center of the Brillouin zone, so the absorption is not a continuous band as for semiconductors, but a sharp line. The existence of this sharp line therefore does not mean that the exciton band is narrow (i.e., that its dispersion relation in the Brillouin zone is flat). On the contrary, since that dispersion is caused by dipolar interactions, exciton bandwidths can be several eV [168,170] the total bandwidth is four times the coupling term. This will be particularly... [Pg.586]

The goal of the method is to perform a random walk in space. Consider a system consisting of N particles interconnected to form a molecule, and having volume V and temperature T. The end-to-end distance of the molecule ( ) can be discretized into distinct states each state is characterized by its end-to-end distance, in some specified range of interest [, +j and represent a lower and an upper bound, respectively. The partition function 17 of this expanded ensemble is given by... [Pg.83]


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