Dissipative structures stable stationary

There are two types of macroscopic structures equilibrium and dissipative ones. A perfect crystal, for example, represents an equilibrium structure, which is stable and does not exchange matter and energy with the environment. On the other hand, dissipative structures maintain their state by exchanging energy and matter constantly with environment. This continuous interaction enables the system to establish an ordered structure with lower entropy than that of equilibrium structure. For some time, it is believed that thermodynamics precludes the appearance of dissipative structures, such as spontaneous rhythms. However, thermodynamics can describe the possible state of a structure through the study of instabilities in nonequilibrium stationary states. 

The experimentally observed manifestations of nonequdibricity of the stable catalyst state usually is less spectacular than those resulting in the for mation of dissipative structures. The most frequently observed manifesta tions of the stable nonequilibrium state are those in homogeneous systems, when the stationary concentrations of catalytic intermediates are substantially different in the course of the catalytic process and in the equilibrium system. 

Another type of dynamic self-organization, so-called dissipative structure , is known as a general physical phenomenon which is generated under chemical or physical conditions far from equilibrium [238]. Many spatiotemporal patterns of the dissipative structures are formed in the dissipative processes ranging in size from sub-micrometers to hundreds of kilometers. Several types of regular patterns, e.g. spirals in the Belousov-Zhabotinsky reaction systems, the honeycomb and stripes of Rayleigh/Benard convection, are formed as spatiotemporal patterns in the dissipative processes. To utilize the dissipative structures for self-organization of molecular assemblies, the spatiotemporal patterns have to be frozen as stationary stable structures. 

The dissipative structure is essentially a dynamic structure requiring continual energy dissipation, but dynamic structures can be frozen as stationary stable structures. The casting process of polymer solutions on solid siufaces is complex enough to form dissipative structures. Thus, some spatiotemporal polymer pat-... 

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