Cross conformational properties

Kinetics of Intramolecular Cross-Linking and Conformational Properties of Cross-Linked Chains... 

The method of mathematical simulation has many advantages, and is very close to the physical experiment. However the further development of this approach /a consideration of volume effects, reversible reactions and so onj can be rather difficult because it will reau.ire too much computer time, therefore it is expedient to search some simple analytical or semianalytical approximate approaches to the calculation of cross-linking kinetics and conformational properties of cross-linked macromolecules. The results obtained bv the Fonte Carlo calculation can serve as criteria of the accuracy of such approximation. 

Thus the approach described can be apolied to the description of the kinetics of intramolecular cross-linking and the conformational properties of cross-linked products. 

Finally we note some recent molecular dynamics simulations with the use of atom-atom potential," "" which can provide useful information concerning the relation between the detailed molecular composition, the phase behavior, and dynamical properties of the system. However, due to the large number of interaction sites in real molecular systems, the calculations are extremely time consuming, and therefore only a few liquid crystals have been studied in this way. Some simplifications are introduced to circumvent part of the difficulties. "" In the approach by Cross and Fung" " the phenyl rings in the LC molecules are considered as enlarged simple spheres, whereas other parts of the molecule are treated realistically. Inter- and intramolecular contributions arising from the alkyl chain to the conformational properties could be separated. In the model proposed by Yoshida and Toriumi," the LC... 

Dl A. Supercoiling. Supercoiling is a topological property of closed-circular DNA molecules. Circular DNA molecules can exist in various conformations differing in the number of times one strand of the helix crosses the other. These different isomeric conformations are called topoisomers and maybe characterized in terms of the linking number, Ek. A linear DNA molecule having Nbase pairs and h base pairs per turn of the helix, if joined end to end, has the following ... 

---