Type Ia supernovae (SNe) play a key role in the determination of the cosmological parameters because their absolute luminosities can directly be derived from measurements of their light curves. Despite several decades of observations and theoretical studies, the nature of SN Ia progenitors is still unknown, and this fact brings ambiguity into the interpretation of recent cosmological results. O...

Reduction of an N-heterocyclic carbene (NHC) adduct of SnCl(2), viz. [(IPr)SnCl(2)] (IPr = :C{N(Dip)C(H)}(2); Dip = 2,6-diisopropylphenyl), with a magnesium(I) dimer, has afforded the first NHC complex of a row 5 element in its diatomic form, [(IPr)Sn=Sn(IPr)]; a computational analysis of the complex indicates that it comprises a singlet state, doubly bonded tin(0) fragment, :Sn=Sn:, datively b...

We study the structure of the circumstellar medium surrounding SN 1987A in the equatorial plane. Furthermore, we study the evolution of the SN shock within this medium during the first 25 years, and the resulting hard X-ray and radio emission from the remnant.

In this research, first, nanoparticles of SrFe11.98Mg0.1Sn0.1O19 hexaferrite was synthesized via sol-gel auto-combustion process and then the nanocomposites of hexagonal ferrites/perovskite with the amounts of SrFe11.98Mg0.1Sn0.1O19/BaTiO3 (50/50, 40/60, 70/30 w/w) was prepared by the ball-milling...

In particular, chalcogenide glasses and glass-ceramics are new materials that exhibit good transparency in infrared region (0.8-12µm). We can overcome the main weakness of these glasses by improving the hardness through controlling crystallization. In this paper, we report results of a study on chalcogenide glasses in the ternary system of As-Se-Ge with nominal composition of Snx (Se...

Silver (SN) nanoparticles were re‐dispersed in aqueous solution of Pluronic F127 and complexed with the antioxidant, alpha‐ Lipoic acid (LA). The nanoparticle ‐ LA complex (SN‐LA) was characterized using SEM. SN‐ LA exhibited DPPH radical scavenging activity in vitro and anti‐ inflammatory activity against acute and chronic paw models of edema in mice. SN‐LA protected ...

The six-coordinate Sn(IV) atom in the title compound, [Sn(C(8)H(9))Cl(3)(C(3)H(4)N(2))(2)], shows an octa-hedral coordination. The N atoms of the N-heterocycle are cis to each other. The Sn-N bond that is trans to the Sn-C bond is shorter than the Sn-N bond trans to the Sn-Cl bond. Weak N-H⋯Cl hydrogen bonds link adjacent mol-ecules, generating a double chain running along the c axis.

Sn(π1, π2, . . . , πr) denotes the set of permutations of length n that have no subsequence with the same order relations as any of the πi. In this paper we show that |Sn(1342, 2143)| = |Sn(3142, 2341)| and |Sn(1342, 3124)| = |Sn(1243, 2134)|. These two facts complete the classification of Wilf-equivalence classes for pairs of permutations of length four. In both instances we exhibit bijections...

We discuss a Galerkin approximation scheme for the elliptic partial differential equation −∆u+ ω2u = f on Sn ⊂ Rn+1. Here ∆ is the Laplace-Beltrami operator on Sn, ω is a non-zero constant and f belongs to C2k−2(Sn), where k ≥ n/4 + 1, k is an integer. The shifts of a spherical basis function φ with φ ∈ H τ (Sn) and τ > 2k ≥ n/2 + 2 are used to construct an approximate solution. An H1(Sn)error ...

The title compound, [Sn(2)(C(4)H(9))(2)(C(12)H(20))(2)], has two 1-stannacyclo-penta-diene skeletons related by inversion symmetry located at the mid-point of the Sn-Sn bond [2.7682 (2) Å]. Thus, the asymmetric unit comprises one half-mol-ecule. The planarity of the stannacyclo-penta-diene ring is illustrated by the dihedral angle of 0.3 (1)°, defined by the C(4) and C-Sn-C planes. To avoid ste...