Compensation for coarticulation despite a midway speaker change: Reassessing effects and implications.

Accounts of speech perception disagree on how listeners demonstrate perceptual constancy despite considerable variation in the speech signal due to speakers' coarticulation. According to the spectral contrast account, listeners' compensation for coarticulation (CfC) results from listeners perceiving the target-segment frequencies differently depending on the contrastive effects exerted by the preceding sound's frequencies. In this study, we reexamine a notable finding that listeners apparently demonstrate perceptual adjustments to coarticulation even when the identity of the speaker (i.

On Field-Effect Photovoltaics: Gate Enhancement of the Power Conversion Efficiency in a Nanotube/Silicon-Nanowire Solar Cell.

Recent years have seen a resurgence of interest in crystalline silicon Schottky junction solar cells distinguished by the use of low density of electronic states (DOS) nanocarbons (nanotubes, graphene) as the metal contacting the Si. Recently, unprecedented modulation of the power conversion efficiency in a single material system has been demonstrated in such cells by the use of electronic gating. The gate field induced Fermi level shift in the low-DOS carbon serves to enhance the junction built-in potential, while a gate field induced inversion layer at the Si surface, in regions remote from the junction, keeps the photocarriers well separated there, avoiding recombination at surface traps and defects (a key loss mechanism).

Extraordinary hydrogen evolution and oxidation reaction activity from carbon nanotubes and graphitic carbons.

The hydrogen evolution reaction, 2H(+) + 2e(–) → H2, and its converse, the hydrogen oxidation reaction, H2 → 2H(+) + 2e(–), are central to any realization of a hydrogen economy. Various forms of carbon have been used for decades as the precious metal catalyst support in these reactions. Here we report the unexpected result that single-wall carbon nanotubes and some graphitic carbons, activated by brief exposure to electrochemical potentials that induce hydrogen evolution in intercalating acids combined with extended soak times in such acids, acquire an activity for these reactions that exceeds that of known nonprecious metal catalysts.

Improved transfer of graphene for gated Schottky-junction, vertical, organic, field-effect transistors.

An improved process for graphene transfer was used to demonstrate high performance graphene enabled vertical organic field effect transistors (G-VFETs). The process reduces disorder and eliminates the polymeric residue that typically plagues transferred films. The method also allows for purposely creating pores in the graphene of a controlled areal density.

Current transport across the pentacene/CVD-grown graphene interface for diode applications.

We investigate the electronic transport properties across the pentacene/graphene interface. Current transport across the pentacene/graphene interface is found to be strikingly different from transport across pentacene/HOPG and pentacene/Cu interfaces. At low voltages, diodes using graphene as a bottom electrode display Poole–Frenkel emission, while diodes with HOPG and Cu electrodes are dominated by thermionic emission.