Field Effects on the Statistical Behavior of the Molecular Conductance in a Single Molecular Junction in Aqueous Solution

We have combined molecular dynamics simulations with first-principles calculations to study electron transport in a single molecular junction of perylene tetracarboxylic diimide (PTCDI) in aqueous solution under external electric gate fields. It is found that the statistics of the molecular conductance are very sensitive to the strength of the electric field. The statistics of the molecular conductance are strongly associated with the thermal fluctuation of the water molecules around the PTCDI molecule. Our simulations reproduce the experimentally observed three orders of magnitude enhancement of the conductance, as well as the temperature dependent conductance, under the electrochemical gates. The effects of the molecular polarization and the dipole rearrangement of the aqueous solution are also discussed.

PROPAGATION OF SHORT FATIGUE CRACKS IN STEEL 16Mn

Small bar speeimens of steel 16Mn with blind-holes were fatigued under constant amplitude Ioadings on a rotathing bending fatigue machie.Short crack propagation emanating from the blind-holes was obtained.Based on the experimental results,an expression of average propa- gation rate of short cracks was proposed.Statistical behavior of short crack propagation was discussed and the evoluation of sutrface sizes of short cracks with fatigue cycle number was al- so given.

Universal behaviors of magnon-mediated spin transport in disordered nonmagnetic metalferromagnetic insulator heterostructures

We numerically investigate magnon-mediated spin transport through nonmagnetic metal/ferromagnetic insulator(NM/FI)heterostructures in the presence of Anderson disorder,and discover universal behaviors of the spin conductance in both one-dimensional(1D)and 2D systems.In the localized regime,the variance of logarithmic spin conductanceσ2(lnGγ)shows a universal linear scaling with its average(lnGγ),independent of Fermi energy,temperature,and system size in both 1D and 2D cases.In 2D,the competition between disorder-enhanced density of states at the NM/FI interface and disorder-suppressed spin transport leads to a non-monotonic dependence of average spin conductance on the disorder strength.As a result,in the metallic regime,average spin conductance is enhanced by disorder,and a new linear scaling between spin conductance fluctuation rms(GT)and average spin conductance GT is revealed which is universal at large system width.These universal scaling behaviors suggest that spin transport mediated by magnon in disordered 2D NM/FI systems belongs to a new universality class,different from that of charge conductance in 2D normal metal systems.

Suboptimal Auditory Dominance in Audiovisual Integration of Temporal Cues

The present study examined whether audiovisual integration of temporal stimulus features in humans can be predicted by the maximum likelihood estimation （MLE） model which is based on the weighting of unisensory cues by their relative reliabilities. In an audiovisual temporal order judgment paradigm, the reliability of the auditory signal was manipulated by Gaussian volume envelopes, introducing varying degrees of temporal uncertainty. While statistically optimal weighting according to the MLE rule was found in half of the participants, the other half consistently overweighted the auditory signal. The results are discussed in terms of a general auditory bias in time perception, interindividual differences, as well as in terms of the conditions and limits of statistically optimal multisensory integration.