Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Single transition systems classification

In transition metal-catalyzed domino reactions, more than one catalyst is often employed. In Tietze s definition and the classification of domino reactions, no distinction has been made between transformations where only one or more transition metal catalyst is used for the different steps, provided that they take place in a chronologically distinct order. Poli and coworkers [13] differentiated between these processes by calling them pure-domino reactions (which consisted of a single catalytic cycle driven by a single catalytic system) or pseudo-domino reactions . The latter type was subdivided into ... [Pg.359]

First-Order Transitions. The principal transitions in macromolecules are those concerned with enthalpy (latent heat) and entropy changes. They are called first-order transitions according to a classification requiring the first derivative of the change in free enthalpy with respect to temperature not to be zero (92). For a single-component system (pure compound), thermodynamic equilibrium states... [Pg.8437]

For adsorbents with sufficiently laig e porosities (often referred to as mesoporous systems) isotherms can exhibit hysteresis between the adsorption and desorption branches as illustrated schematically in figure 1. A classification of the kinds of hysteresis loops has also been made. It is generally accepted that such behavior is related to the occurrence of capillary condensation - a phenomenon whereby the low density adsorbate condenses to a liquid like phase at a chemical potential (or bulk pressure) lower than that corresponding to bulk saturation. However, the exact relationship between the hysteresis loops and the capillary phase transition is not fully understood - especially for materials where adsorption cannot be described in terms of single pore behavior. [Pg.22]

The study of stacked hexatics has yielded a complete classification of the large variety of thermotropic liquid crystal phases. It has also presented a single experiment which yields a simultaneous measurement of many crossover anisotropy exponents, previously obtained from separate complex experiments. It is also an excellent system to reveal dimensional crossover and the interplay between two- and three-dimensional physics. For very thin layers, the stacked hexatic layers can be used to extract the hexatic stiffness, or Frank constant, and thus test predictions of defect mediated transition theories. [Pg.62]


See other pages where Single transition systems classification is mentioned: [Pg.350]    [Pg.1206]    [Pg.47]    [Pg.138]    [Pg.163]    [Pg.36]    [Pg.202]    [Pg.274]    [Pg.58]    [Pg.180]    [Pg.262]    [Pg.176]    [Pg.187]    [Pg.159]    [Pg.70]    [Pg.250]    [Pg.263]    [Pg.185]    [Pg.85]   
See also in sourсe #XX -- [ Pg.224 ]




SEARCH



Classification system

Single system

Single transition systems

Transit system

© 2024 chempedia.info