11.2.2 Fluctuational Mechanisms

Ramachandran GK, Hopson TJ, Rawlett AM, Nagahara LA, Primak A, Lindsay SM (2003) A bond-fluctuation mechanism for stochastic switching in wired molecules. Science 300 1413-1416... 

The circumstances producing an e.e. on the early Earth could well have been capture and amplification of one of the fluctuational mechanisms outlined above, although present evidence favors the meteoric infall of chiral molecules synthesized in interstellar dust douds. The total flux of organics on the early Earth, delivered to Earth both by way of comets and other bolides, and synthesized by terrestrial mechanisms... 

CONDENSATION ENERGY FOR SPIN FLUCTUATIONS MECHANISM OF PAIRING IN HIGH-TC SUPERCONDUCTORS... 

Key words Condensation energy, spin fluctuation mechanism of pairing, thermodynamic, underdoped region, pseudogap... 

In this present paper we ll calculated the condensation energy on basis of antiferromagnetic spin fluctuation mechanism of pairing in high-Tc superconductors. 

It was shown that the temperature dependence of the specific heat of the spin-fluctuations mechanism in cuprate superconductors proportional to square the temperature, which correspond d wave pairing [6,9]... 

Dahm, T., Erdmenger, 1., Schamberg, K., and Rieck, C. T. (1993). Superconducting states from spin-fluctuation mechanisms. Phys. Rev. B, 48 3896. 

Keywords high-Tc superconductivity, spin-fluctuation mechanism... 

Condensation Energy for Spin Fluctuations Mechanism of Pairing in High-Tc Superconductors 145... 

The spectroscopic data have been compared with the theoretical predictions of the Doi- Edwards model. In the time scale of our experiments, a quantitative agreement between experiment and theory is obtained if chain length fluctuations, retraction and reptation are taken into account. In the case of star polymers, the large scale fluctuation mechanism as proposed by Pearson and Helfand associated with the retraction process is accounting for... 

The quality of our resistivity data and the sharpness of the transition to the superconducting state allow a test of various fluctuation mechanisms. We have attempted to fit p(T) near to three-, two-, one-, and zero-dimensional fluctuation expressions (8). In all cases, the agreement with experimental data is poor. Hence, we conclude that K3C60 displays no substantial fluctuation conductivity near the onset to the superconducting state. 

Metal fatigue is the process of crack initiation and growth due to the action of a fluctuating mechanical stress. Corrosion fatigue is simply metal fatigue that... 

The quantity is a part of the line width, which is due to the fluctuational mechanism and is designated as T in eq. (168). Its value does not depend on the resonance frequency o>o at parallel orientation at other orientations that dependence has an approximate form Tj =c +c"v. The measurements in TmES at high frequencies (v>20MHz) confirm the expected dependence (fig. 19). At low frequencies the temperature-dependent broadening is small, and the lineshape is strongly deflected from the Lorentzian. 

Two relaxation mechanisms are connected with interionic interactions, the Waller mechanism and the ductuational one, considered in detail earlier in this section for nuclear relaxation of ligands of the VV ions. Estimates of the relaxation rate, due to modulation of dipole-dipole interactions by lattice vibrations, result in T 7 10 exp(-4/A B7 ) for impurities in TmES, which is by far less than the experimental values. The relaxation rate for the fluctuational mechanism is calculated analogously to eq. (188) here the result is presented for the case of the model three-level VV ions at arbitrary orientation 0 of an applied field relative to the c-axis ... 

Mode of activation Convection currents Electronic excitation Electron transfer at the electrode Cavitation Dipole fluctuation Mechanical... 

The second determining factor is the dampening factor 5. It includes all accidental limitations able to broaden I(s), notably the instrumental response (e.g., X fluctuations, mechanical vibrations, strains). It also greatly impedes the resolution of l s), preventing peak separation in P(x). As an example, 5 = 0.115 introduces in P x) an arbitrary increase in the width of the peaks of 0.38 A. As a result, peaks distant from less than 0.4 A cannot be separated. 

Environmental influence to the detector None (minimum sensitivity to operating temperature fluctuations, mechanical shocks, vibrations, radiation, signal or supply overload, etc.)... 

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