STM-induced light emission from thin films of perylene derivatives on the HOPG and Au substrates

We have investigated the emission properties of N,N'-diheptyl-3,4,9,10-perylenetetracarboxylic diimide thin films by the tunneling-electron-induced light emission technique. A fluorescence peak with vibronic progressions with large Stokes shifts was observed on both highly ordered pyrolytic graphite (HOPG) and Au substrates, indicating that the emission was derived from the isolated-molecule-like film condition with sufficient π-π interaction of the perylene rings of perylenetetracarboxylic diimide molecules. The upconversion emission mechanism of the tunneling-electron-induced emission was discussed in terms of inelastic tunneling including multiexcitation processes. The wavelength-selective enhanced emission due to a localized tip-induced surface plasmon on the Au substrate was also obtained

Phonetics of Polish "soft"-"hard" vowel allophony

This paper reports on the results of a three-dimensional ultrasound study of Polish vowels in consonant-vowel sequences. It was found that allophonic variation in vowels in the context of “soft” consonants is consistently implemented phonetically by means of tongue root advancement, which effectively expands the pharyngeal cavity and reduces the volume of the oral cavity. The tongue root is also consistently advanced in the soft consonants that trigger vowel allophony and retracted (or neutral) in the “hard” sounds, which do not trigger allophony, suggesting that tongue root advancement is part of the phonological representation of the “softness” (or palatalization) contrast. In parallel to this allophony, the same tongue root mechanism was found to underlie the phonotactic distribution of the phonemic vowels /i/ and /ɨ/, yielding an entirely symmetric system with consonant-vowel sequences always obligatorily compatible in terms of the position of the tongue root

GaAs/AlGaAs nanowire heterostructures studied by scanning tunneling microscopy

We directly image the interior of GaAs/AlGaAs axial and radial nanowire heterostructures with atomic-scale resolution using scanning tunneling microscopy. We show that formation of monolayer sharp and smooth axial interfaces are possible even by vapor-phase epitaxy. However, we also find that instability of the ternary alloys formed in the Au seed fundamentally limits axial heterostructure control, inducing large segment asymmetries. We study radial core-shell nanowires, imaging even ultrathin submonolayer shells. We demonstrate how large twinning-induced morphological defects at the wire surfaces can be removed, ensuring the formation of wires with atomically flat sides

Phonetics of Polish “soft”-“hard” vowel allophony

This paper reports on the results of a three-dimensional ultrasound study of Polish vowels in consonant-vowel sequences. It was found that allophonic variation in vowels in the context of “soft” consonants is consistently implemented phonetically by means of tongue root advancement, which effectively expands the pharyngeal cavity and reduces the volume of the oral cavity. The tongue root is also consistently advanced in the soft consonants that trigger vowel allophony and retracted (or neutral) in the “hard” sounds, which do not trigger allophony, suggesting that tongue root advancement is part of the phonological representation of the “softness” (or palatalization) contrast. In parallel to this allophony, the same tongue root mechanism was found to underlie the phonotactic distribution of the phonemic vowels /i/ and /ɨ/, yielding an entirely symmetric system with consonant-vowel sequences always obligatorily compatible in terms of the position of the tongue root

The ALEX17 diurnal cycles in complex terrain benchmark:Paper

The NEWA ALEX17 experiment was conducted with the objective of characterizing the wind conditions upstream of the Alaiz Test Site for the validation of flow models. From the intensive operational period, a case study has been selected for a Wakebench benchmark consisting of four consecutive days with relatively persistent winds from the North. The validation is centered around a 118-m mast at the Alaiz site and six additional masts located along the valley and at the lee side of a ridge delimiting a 8-km long area of interest. The benchmark is a follow-up of the GABLS3 diurnal cycle benchmark in flat terrain to test mesoscale-to-microscale transient and steady-state modeling methodologies in the assessment of stability-dependent bin-averaged wind conditions. Meso-micro methodologies reduce the wind speed mean bias from 32%, at 3-km mesoscale, to ±5%. Beyond mean bias mitigation, these initial results demonstrate the added value of meso-micro coupling at reproducing non conventional wind conditions at the test site like high-shear low-level jets in stable conditions and negative wind shear in unstable conditions. The benchmark also discusses the challenges of each meso-micro methodology going forward.This work was carried out under the umbrella of the International Energy Agency IEA-Wind TCP Task 31 Wakebench, with the support from: MARINE2 (EU grant agreement number 731084) UPWARDS (EU grant agreement number 763990), EoCoE-II (EU grant agreements number 824158 and 828947) and the Mexican Department of Energy, CONACYT-SENER Hidrocarburos grant agreement number B-S-69926Peer ReviewedPostprint (published version