Single macromolecule problem

B. Self-Consistent Solution of Single Macromolecule Problem... 

This equation is the general equation for the dynamics of a single macromolecule in the case of linear dependence on the co-ordinates and velocities. However, the memory functions cannot be determined from general considerations to calculate them one has to return to many-chain approaches. The value of these approaches to the problem is the possibility of evaluating the memory function through the intermolecular correlation functions and structural dynamic factor. Another way to solve the problem is to use some simple model considerations, as in works by Pokrovskii and Kokorin [59, 60]. 

Davtyan et al. analyzed the problem of changes mass distribution with conversion during the polymerization of heterocycles [58], This case is interesting the question of the coexistence of one or two active centres on a single growing macromolecule is solved by means of rate equations. The results can also be applied to polymerizations of other monomers, when the conditions... 

Excellent and detailed treatments of the use of anomalous dispersion data in the deduction of phase information can be found elsewhere (Smith et al., 2001), and no attempt will be made to duplicate them here. The methodology and underlying principles are not unlike those for conventional isomorphous replacement based on heavy atom substitution. Here, however, the anomalous scatterers may be an integral part of the macromolecule sulfurs (or selenium atoms incorporated in place of sulfurs), the iron in heme groups, Ca++, Zn++, and so on. Anomalous scatterers can also be incorporated by diffusion into the crystals or by chemical means. With anomalous dispersion techniques, however, all data necessary for phase determination are collected from a single crystal (but at different wavelengths) hence non-isomorphism is less of a problem. 

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