Search results for "optica"

Gas-Phase Hydrogenation of Propionitrile Catalyzed by LnCu2 (Ln = La, Ce, Pr, Nd)

2007

The hydrogenation of propionitrile over binary copper−lanthanide intermetallic compounds (LnCu2, Ln = La, Ce, Pr, Nd) was studied in the gas phase. The results show that the reaction main product is the primary amine, the n-propylamine. To our knowledge, it is the first time that such behavior is reported for copper catalysts.

UV variability and accretion in NGC 2264

2015

Photometric variability is a distinctive feature of young stellar objects; exploring variability signatures at different wavelengths provides insight into the physical processes at work in these sources. We explore the variability signatures at ultraviolet (UV) and optical wavelengths for several hundred accreting and non-accreting members of the star-forming region NGC 2264 (~3Myr). Cone search capability for table J/A+A/581/A66/table2 (Median photometry, variability amplitudes, light curve rms, J index, and color slopes for members monitored at CFHT)

Variability in proto-PNe. II.

2014

We have carried out a detailed observational study of the light, color, and velocity variations of two bright, carbon-rich proto-planetary nebulae, IRAS 22223+4327 and 22272+5435. The light curves are based upon our observations from 1994 to 2011, together with published data by Arkhipova and collaborators. They each display four significant periods, with primary periods for IRAS 22223+4327 and 22272+5435 being 90 and 132 days, respectively. For each of them, the ratio of secondary to primary period is 0.95, a value much different from that found in Cepheids, but which may be characteristic of post-asymptotic giant branch (AGB) stars. Fewer significant periods are found in the smaller radia…

Radio-optical scrutiny of compact AGN

2010

We study the correlations between the VLBA (Very Long Baseline Array) radio emission at 15GHz, extended emission at 151MHz, and optical nuclear emission at 5100{AA} for a complete sample of 135 compact jets. We use the partial Kendall's tau correlation analysis to check the link between radio properties of parsec-scale jets and optical nuclear luminosities of host active galactic nuclei (AGN). Cone search capability for table J/A+A/520/A62/table3 (Optical and radio parameters of 135 AGN)

Radiation Effects on Aluminosilicate Optical Fibers: Spectral Investigations From the Ultraviolet to Near-Infrared Domains

2019

Local Structure Studies of Ti for SrTi16O3 and SrTi18O3 by Advanced X-ray Absorption Spectroscopy Data Analysis

2015

Strontium titanate is a model quantum paraelectric in which in the region of dominating quantum statistics the ferroelectric instability is inhibited due to nearly complete compensation of the harmonic contribution into ferroelectric soft mode frequency by the zero-point motion contribution. The enhancement of atomic masses by the substitution of 18O for 16O decreases the zero-point atomic motion and low-T ferroelectricity in SrTi18O3 is realized. In this study we report on the local structure of Ti in SrTi16O3 and SrTi18O3 by Ti K-edge extended x-ray absorption fine structure measurements in temperature range 6 – 300 K.

The S … Hal and Se … Hal chalcogen bonding in a series of thiourea, selenourea and their derivatives

2021

The chalcogen bonding (ChB) in a series of thiourea, selenourea and their derivatives has been investigated in the present paper. Thus, selenourea and dimethylselenourea undergo dimerization and trimerization processes in the presence of various halogen species (1–5). Selenourea and dimethylselenourea form trimers 3–4 in the presence of lighter halogens (chlorine and bromine) through Se⋯Se chalcogen bonding. When moving to heavier halogen (iodine), the dimers 1–2 are formed. Thiourea and its derivatives also tend to make very strong S⋯S bonds and form dimers in the case of lighter halogens chlorine and bromine (compounds 6–7). However, the monomers separated by the iodine species are formed…

Deterministic Modification of CVD Grown Monolayer MoS2 with Optical Pulses

2021

| openaire: EC/H2020/820423/EU//S2QUIP | openaire: EC/H2020/834742/EU//ATOP Transition metal dichalcogenide monolayers have demonstrated a number of exquisite optical and electrical properties. Here, the authors report the optical modification of topographical and optical properties of monolayer MoS2 with femtosecond pulses under an inert atmosphere. A formation of three-dimensional structures on monolayer MoS2 with tunable height up to ≈20 nm is demonstrated. In contrast to unmodified monolayer MoS2, these optically modified structures show significantly different optical properties, such as lower photoluminescence intensity and longer fluorescence lifetime. The results suggest a novel way…

Tetracyclic silaheterocycle formed through a pericyclic reaction cascade including a two-fold intramolecular C–C bond activation

2022

Reductive debromination of the tribromoamidosilane 2 gave the tetracyclic silaheterocycle 3 through a unique reaction cascade involving unprecedented two-fold intramolecular cycloaddition by transient silylenes. Experimental and computational analyses of the reaction mechanism allowed the identification of the key intermediates that lead to the silaheterocycle 3 or, alternatively, to the cyclotrisilene 19. peerReviewed

Reply to : “Topological and trivial domain wall states in engineered atomic chains”

2022

publishedVersion Non peer reviewed