Asymmetric interactions

A substance displays optical activity Molecules of the substance are asymmetrical. Interactions between the molecules and electromagnetic radiation is such that the plane of polarisation of the radiation is always rotated in the same direction... 

When using single-crystal electrodes, it is assumed that the structure of their surfaces reflects the structure of the bulk crystal. However, it appears that, frequently, the surface structure is different from that of the bulk due to their different atomic surroundings. In the bulk crystal, each metal atom is surrounded by identical atoms fixed within the well-defined structure. In contrast, the surface atoms participate in the interactions with metal atoms forming the crystal, and are involved as well in the interactions with the components of the solution at the solid/liquid interface. These asymmetrical interactions of the surface atoms may lead to the breakage of the old and formation of the new bonds, followed by the displacement of the surface atoms to the positions of the lower surface energy. The process of formation... 

Garbriel, B., Teissie, J. (1997). Direct observation in the millisecond time range of fluorescent molecule asymmetrical interaction with the electropermeabilized cell membrane. Biophys. J., 73, 2630-2637. 

Finally in the case of the Ga-Sb and In-Sb binaries the relative chemical potentials of the Group III element in the liquid phase have been determined experimentally. The experimental value at x = and some temperature T = T can be matched exactly using Eq. (88). The left-hand side is the experimental value so that the equation can be used to express one asymmetric interaction coefficient, say , in terms of the other, /J13. 

The first term in the brackets arises from isotropic expansion, while the second from plane wave disturbances. However, it is very unclear whether or not Eq. (4.54) is applicable to our problem. This is because the free energy density for c is already strongly affected by asymmetric interactions of the polymer with the two fluid components. 

We tentatively conclude that the asymmetrical interaction of the homeodomain protein with DNA gives it a versa-... 

Balleine B (1994) Asymmetrical interactions between thirst and hunger in Pavlovian-instrumental transfer. Q J Exp Psychol, Sect B, Comp Physiol Psychol 7(2) 211-231. 

Conte E (1985) Investigation on the chirality of electrons from 90Sr-90Y beta-decay and their asymmetrical interactions with D-and L-alanines. Lettere Al Nuovo Cimento (1971-1985) 44 641-647... 

Figure 7 Experimental signal recorded for photolyzed MbCO. Fe-ligand vibrations dominate the cluster of modes observed in the 230-270 cm region. The clearly resolved frequency separation between the in-plane Fe-N, yr frequencies at 251 and 267 cm reflects the asymmetric interactions with the histidine ligand. The Fe-histidine stretching frequency appears at 234cm L Data were recorded under continuous illumination by a 15 mW helium neon laser with k = 633 nm. The temperature of a sensor mounted in the sapphire sample block was 15 K...

For liquids near surfaces the radial distribution functions become asymmetrical and are generally more difficult to handle. The situation is again relatively simple for molecularly flat surfaces when only density variations normal to the surface have to be considered. This is, for instance, the case for spherically symmetrical molecules for rods, or molecules with asymmetrical interaction (water), the situation is again more complicated. In that case one can Introduce a (linear) distribution function g[z) as... 

Taking into account the existing indications for asymmetric interactions at the interfaces (e.g., three-layer model in Ref. 4), two distinct cases must be analyzed (i) Both interfaces immobilize the chains or (ii) the chains are immobilized only at one interface while at the other one they are reflected (hard-wall behavior). In Fig. 18 the distribution of the end-to-end distance of terminal subchains is shown when both interfaces immobilize the chain segments. No shifts of the maximum position of the distribution are observed with decreasing film thickness. This result would imply that the confinement-induced mode does not exhibit thickness dependence, in contrast to the experiment. 

For interpretation of the generation of optical activity, three complementary types of asymmetric interactions may be considered [see Ref. (5)], using as a simple model a molecule having two groups and two electronic transitions ... 

Of course, again these data show a dramatic size effect (Fig. 24a) and thus a finite size scaling analysis of the type shown in Fig. 21a is necessary to extract the coexistence curve in the thermodynamic limit In this way an accurate estimation of the phase diagram of polymer mixtures with NA = NB but asymmetric interactions is possible (Fig. 24a, b). 

Smith °" have demonstrated asymmetric interactions in stereospecific substitution reactions. An estimate of the magnitude of the asymmetric interaction in the case of the d and / form of d.s-[CoCl2(en)2] with the solvent (—)-2,3-butanedioF °, from solubility product measurements, suggests that antiracemisationin systems where solvolytic interference is less important (perhaps with m-[Co(N02)2(en)2] ), will lead to interesting kinetics. In this solvent, as well as 1,2-propanediol, such studies, when compared with the racemisation rates of the resolved complexes in the racemic or meso forms of the solvents, must lead to a greater understanding of the role of the solvent in a class of reactions whose precise mechanism has proved difficult to define. 

Rhombic perturbation of haem electronic structure induced by asymmetric interaction of haem with the protein matrix has been thought to be relevant to the... 

Fig. 27. Increasing curvature of the interface between the grey A and white C domains of an ABC triblock copol3maer for increasing asymmetric interactions of the black B domains.

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