29 research outputs found
C-Methylcalix[4]resorcinarene–1,4-bis(pyridin-3-yl)-2,3-diaza-1,3-butadiene (1/2)
In the title compound, 2C12H10N4·C32H32O8, the calixarene adopts a rctt conformation with dihedral angles of 138.40 (1) and 9.10 (1)° between the opposite rings. The dihedral angles between the rings of the pyridine derivative are 8.80 (1) and 9.20 (1)°. In the crystal, adjacent C-methylcalix[4]resorcinarene molecules are connected into columns parallel to [010] by O—H⋯O hydrogen bonds. O—H⋯N hydrogen bonds between the axial phenoxyl groups and bipyridine molecules link the columns into sheets parallel to (011), which are connected by O—H⋯N hydrogen bonds. Further O—H⋯N hydrogen bonds link the bipyridine and C-methylcalix[4]resorcinarene molecules, giving rise to a three-dimensional network
Signatures of the disk-jet coupling in the Broad-line Radio Quasar 4C+74.26
Here we explore the disk-jet connection in the broad-line radio quasar
4C+74.26, utilizing the results of the multiwavelength monitoring of the
source. The target is unique in that its radiative output at radio wavelengths
is dominated by a moderately-beamed nuclear jet, at optical frequencies by the
accretion disk, and in the hard X-ray range by the disk corona. Our analysis
reveals a correlation (local and global significance of 96\% and 98\%,
respectively) between the optical and radio bands, with the disk lagging behind
the jet by days. We discuss the possible explanation for this,
speculating that the observed disk and the jet flux changes are generated by
magnetic fluctuations originating within the innermost parts of a truncated
disk, and that the lag is related to a delayed radiative response of the disk
when compared with the propagation timescale of magnetic perturbations along
relativistic outflow. This scenario is supported by the re-analysis of the
NuSTAR data, modelled in terms of a relativistic reflection from the disk
illuminated by the coronal emission, which returns the inner disk radius
. We discuss the global energetics in
the system, arguing that while the accretion proceeds at the Eddington rate,
with the accretion-related bolometric luminosity erg s , the jet total kinetic energy
erg s, inferred from the dynamical
modelling of the giant radio lobes in the source, constitutes only a small
fraction of the available accretion power.Comment: 9 pages and 6 figures, ApJ accepte
Period changes of the sample of eclipsing binaries with active chromospheres
In this work we present results derived from analysis of the O-C behaviour of ten eclipsing binary systems:
AR Lac, CG Cyg, HP Aur, MM Her, RS CVn, RT And, SV Cam, V471 Tau, WW Dra and CF Tuc. It was proved on
the basis of moments of minima compiled from the literature and new ones determined from recent observations,
that these binaries show long term (19-91 years) modulations of their orbital periods, clearly visible in their OC diagrams. Two possible explanations for this effect are considered: (1) the light-travel time effect due to the presence of a third body orbiting the eclipsing systems; (2) the Applegate mechanism predicting period modulation by changes in the distribution of angular momentum as a star goes through its activity cycles. It was found that in the case of four systems the existence of a third star, orbiting the binary, is a more plausible explanation of observations
SEARCH FOR SPECTROSCOPIC FAMILIES AMONG DIFFUSE INTERSTELLAR BANDS
Diffuse interstellar bands (DIBs)await an explanation for many decades. One expectsthat significant progress in identification of DIBs’carriers will be possible when all the known DIBsare divided into families in such a way that only onecarrier is responsible for all bands belonging to thegiven family. Analysing high resolution optical spectraof reddened stars we test a new method to find outthe first true spectroscopic families among DIBs
Hierarchical Analysis of Short Defects between Metal Lines in CMOS IC
Abstract Current paper proposes a new hierarchical approach to defect-oriented testing of CMOS circuit