Fluctuation static

Section IV is devoted to excitons in a disordered lattice. In the first subsection, restricted to the 2D radiant exciton, we study how the coherent emission is hampered by such disorder as thermal fluctuation, static disorder, or surface annihilation by surface-molecule photodimerization. A sharp transition is shown to take place between coherent emission at low temperature (or weak extended disorder) and incoherent emission of small excitonic coherence domains at high temperature (strong extended disorder). Whereas a mean-field theory correctly deals with the long-range forces involved in emission, these approximations are reviewed and tested on a simple model case the nondipolar triplet naphthalene exciton. The very strong disorder then makes the inclusion of aggregates in the theory compulsory. From all this study, our conclusion is that an effective-medium theory needs an effective interaction as well as an effective potential, as shown by the comparison of our theoretical results with exact numerical calculations, with very satisfactory agreement at all concentrations. Lastly, the 3D case of a dipolar exciton with disorder is discussed qualitatively. 

K. S. Schweizer and J. G. Curro, Macromolecules, 21, 3082 (1988). Integral Equation Theory of Polymer Melts Density Fluctuations, Static Structure Factor, and Comparison with Incompressible and Continuum Limit Models. 

We have investigated various aspects of the microphase separation transition of diblock copolymers P(S-b-B) by small angle x-ray scattering. The temperature dependence of the scattering behavior of P(S-b-B) agrees well with recent theories. It shows a distinct deviation from mean field behavior in the vicinity of Tmst, which may be explained by the influence of thermally induced fluctuations. Static pressure dependent behavior on the other hand seems to be in accordance with the temperature experiments and it seems possible for instance to use a... 

Nuclear spin relaxation is caused by fluctuating interactions involving nuclear spins. We write the corresponding Hamiltonians (which act as perturbations to the static or time-averaged Hamiltonian, detemiming the energy level structure) in tenns of a scalar contraction of spherical tensors ... 

The probability of finding a nucleic acid unit in the certain conformation according to our results is never equal to the unit. It agrees with the idea that NAs are not static but fluctuating, breathing , objects [23]. For example, in RNA molecule with 10 base pairs at the room temperature about 510 base pairs do not take part in the stacking and are not connected with H -bonds [2]. 

The electric field of a molecule however is not static but fluctuates rapidly Although on average the centers of positive and negative charge of an alkane nearly coincide at any instant they may not and molecule A can be considered to have a temporary dipole moment... 

Static and alternating (radio frequency) electric potentials are applied to opposite pairs of rods to give a resultant fluctuating electric field. 

Although equihbrium capacity is the prime concern, few of these closed systems are truly static. Even closed systems have dynamic features or other nonsteady-state aspects, such as temperature fluctuations, moisture ingression, and drydown rates. 

At temperatures above there is no instanton, and escape out of the initial well is accounted for by the static solution Q = Q with the action S ff = PVo (where Vq is the adiabatic barrier height here) which does not depend on friction. This follows from the fact that the zero Fourier component of K x) equals zero and hence the dissipative term in (5.38) vanishes if Q = constant. The dissipative effects come about only through the prefactor which arises from small fluctuations around the static solution. Decomposing the trajectory into Fourier series. 

Eor simplicity we have so far described a native folded protein molecule as being in one single state. However, within this state, the protein molecule does not have a static rigid structure at normal temperatures. Instead, all the atoms are subject to small temperature-dependent fluctuations. The molecule... 

P. Y. Lai. Statics and dynamics of a polymer chain adsorbed on a surface Monte Carlo simulation using the bond fluctuation model. Phys Rev E 49 5420-5430, 1994. 

I. Gerroff, A. Milchev, W. Paul, K. Binder. A new off-lattice Monte Carlo model for polymers A comparison of static and dynamic properties with the bond fluctuation model and application to random media. J Chem Phys 95 6526-6539, 1993. 

The concentration fluctuations arising from the diffusion process in a static solution with a large amount of supporting electrolyte are followed by... 

Even without using numerical methods, one can analyse some physically sound limiting cases of the exact solution for the case of strong collisions (7.64). First of all, (7.64) evidently reduces to the results of Robert and Galatry in the quasi-static case, i.e. when tc — oo. An opposite limiting case of fast fluctuations... 

The polarlsablllty of a molecule will vary during vibrations which change the Internuclear separations. Thus the vibrations of a molecule sitting In an electrical field will be coupled to the field via the polarlsablllty. This should be particularly noticeable for a molecule adsorbed on an electrode surface where the field strength Is typically In the range 10 -10 V cm, The dipole, perpendicular to the surface, Induced In the molecule by the static electric field will fluctuate In step with the normal mode vibrations of the molecule. 

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