4,646 research outputs found
Poly[[aquaÂtrisÂ(μ3-hexaÂmethylÂeneÂtetraÂmine-κ3 N,N′,N′′)trisÂ(p-tolueneÂsulfonato-κO)trisÂilver(I)] trihydrate]
There are three AgI cations, three p-tolueneÂsulfonate (pts) anions, three hexaÂmethylÂeneÂtetraÂmine (hmt) molÂecules and four water molÂecules in the asymmetric unit of the title coordination polymer, {[Ag3(C7H7O3S)3(C6H12N4)3(H2O)]·3H2O}n. Two of the pts anions show positional disorder of their O atoms in 0.60:0.40 and 0.50:0.50 ratios. The AgI ion is coordinated by three hmt molÂecules in an approximate trigonal–planar AgN3 arrangement. In each case, longer Ag—O bonds to a water molÂecule and a pts anion complete a distorted trigonal–bipyramidal AgN3O2 geometry for the metal ion. In the crystal, the bridging hmt molÂecules and pts ions generate a wave-like layer parallel to (001) and O—H⋯O hydrogen-bonding interÂactions consolidate the packing
Binary population synthesis study on supersoft X-ray phase of single degenerate type Ia supernova progenitors
In the single degenerate (SD) scenario for type Ia supernovae (SNe Ia), a
mass-accreting white dwarf is expected to experience a supersoft X-ray source
(SSS) phase. However, some recent observations showed that the expected number
of the mass-accreting WD is much lower than that predicted from theory,
whatever in spiral or elliptical galaxies. In this paper, we did a binary
population synthesis study on the relative duration of the SSS phase to their
whole mass-increasing phase of WDs leading to SNe Ia. We found that for about
40% progenitor systems, the relative duration is shorter than 2% and the
evolution of the mean relative duration shows that it is always smaller than
5%, whatever for young or old SNe Ia. In addition, before SNe Ia explosion,
more than 55% progenitor systems are experiencing a dwarf novae phase, and only
no more than 10% is staying SSS phase. These results are consistent with the
recent observations, and imply that both in early- and late-type galaxies, only
a small fraction of mass-accreting WD resulting in SNe Ia contribute to the
supersoft X-ray flux. So, although our results are not directly related to the
X-ray output of SN Ia progenitor, the low supersoft X-ray luminosity observed
in early type galaxies may have no ability to exclude the validity of SD model.
On the contrary, it is evidence to support the SD scenario.Comment: 9 pages, 5 figures, accepted for publication in RA
(Z)-2-[(2,4-DimethylÂphenÂyl)imino]-1,3-thiaÂzinan-4-one
In the title compound, C12H14N2OS, the 1,3-thiaÂzinane ring displays a screw-boat conformation. In the crystal, pairs of centrosymmetrically related molÂecules are linked by pairs of N—H⋯O hydrogen bonds into dimers. C—H⋯π interÂactions occur between adjacent dimers
Relative entropy of entanglement of a kind of two qubit entangled states
We in this paper strictly prove that some block diagonalizable two qubit
entangled state with six none zero elements reaches its quantum relative
entropy entanglement by the a separable state having the same matrix structure.
The entangled state comprises local filtering result state as a special case.Comment: 5 page
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