Bistable

Figure A3.14.3. Example bifurcation diagrams, showing dependence of steady-state concentration in an open system on some experimental parameter such as residence time (inverse flow rate) (a) monotonic dependence (b) bistability (c) tristability (d) isola and (e) musliroom.

Another important reaction supporting nonlinear behaviour is the so-called FIS system, which involves a modification of the iodate-sulfite (Landolt) system by addition of ferrocyanide ion. The Landolt system alone supports bistability in a CSTR the addition of an extra feedback chaimel leads to an oscillatory system in a flow reactor. (This is a general and powerfiil technique, exploiting a feature known as the cross-shaped diagram , that has led to the design of the majority of known solution-phase oscillatory systems in flow... 

Tyson J J 1979 Csoillations, bistability and eoho waves in models of the Belousov-Zhabotinskii reaotion Ann. New YorkAoad. Sc/. 316 279-95... 

Degn H, GIsen L F and Perram J W 1979 Bistability, osoillations and ohaos in an enzyme reaotion Ann. New York Aoad. Sc/. 316 623-37... 

Clark N A and Lagerwall S T 1980 Submicrosecond bistable electro-optic switching in liquid crystals App/. Phys. Lett. 36 899-901... 

Figure C2.16.6. The energy states of a metastable and bistable muonium in Si are illustrated in a configuration diagram. It plots the defect energy as a function of a coordinate which combines position and all the relaxations and distortions of the crystal. The specific example, discussed in the text, illustrates acceptor and donor levels, metastability, bistability and negative- U [50] behaviour.

For a one-dimensional bistable potential with the transition state positioned along the reaction coordinate x x = x, the TST rate for forward reaction is defined as... 

Chiral Smectic. In much the same way as a chiral compound forms the chiral nematic phase instead of the nematic phase, a compound with a chiral center forms a chiral smectic C phase rather than a smectic C phase. In a chiral smectic CHquid crystal, the angle the director is tilted away from the normal to the layers is constant, but the direction of the tilt rotates around the layer normal in going from one layer to the next. This is shown in Figure 10. The distance over which the director rotates completely around the layer normal is called the pitch, and can be as small as 250 nm and as large as desired. If the molecule contains a permanent dipole moment transverse to the long molecular axis, then the chiral smectic phase is ferroelectric. Therefore a device utilizing this phase can be intrinsically bistable, paving the way for important appHcations. 

For a simple bistable reaction potential, it is clear that maximum curvamre along the reaction pathway will occur near the extrema—the minima and the barrier top. The path endpoints are typically chosen to sit in the reactant and product minima, and in such a case the maximum error will result from the path straddling the barrier top as in Figure 8. Of course, this is the error made in a single segment of the pathway. For a general potential the pathway will consist of multiple segments and may have many barriers. 

C. Flamet, E. Clement, P. Leroux-Hugon, L. M. Sander. Exact dynamics of a bistable chemical reaction model. J Phys A (Math Gen) 25 L1317-L1322, 1992. 

Ient93] Lent, C.S., P.D.Tougaw and W.Porod, Bistable saturation in coupled quantum dots for quantum cellular automata, Appl. Phys. Lett. 62 (1993) 714-716. 

MoriY, Yamano K, and Hashimoto H. 1996. Bistable aggregate of al I -/rani-astaxanthin in an aqueous solution. Chemical Physics letters 254(1-2) 84—88. 

Mori, Y., K. Yamano, and H. Hashimoto. 1996. Bistable aggregate of all-fraws-astaxanthin in an aqueous solution. Chem. Phys. Lett. 254 84-88. 

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