Perfect state transfer on weighted graphs of the Johnson scheme

Letters in Mathematical Physics - We characterize quantum perfect state transfer on real-weighted graphs of the Johnson scheme $${\mathcal {J}}(n,k)$$ , which represent spin networks with...     

An alternative approach to the synthesis of the carbapenam ring system. Allenes as acceptor-donor reagents in 3 + 2 annelations

1,1-Dichloro-3-methylsulfonyl-3-methylthio-1,2-propadiene, generated in situ under basic conditions, reacted with a 4-iodomethylazetidinone to give a carbapenam. Subsequent efforts to convert this material to a Δ-2-carbapenem by rearrangement of an allylic sulfoxide led instead to the formation of a novel Δ-1-carbapenem.     

Little and big q-Jacobi polynomials and the Askey–Wilson algebra

The Ramanujan Journal - The little and big q-Jacobi polynomials are shown to arise as basis vectors for representations of the Askey–Wilson algebra. The operators that these polynomials...     

Capture and Controlled Release of Fragrances by CD Finished Textiles

Cotton, wool and polyester fabrics finished with cyclodextrins (by the intermediateof polycarboxylic acids) were impregnated with six different fragrant molecules(-citronellol, camphor, menthol, cis-jasmone, benzyl acetate, geraniol) and citronella oil. The smell intensity of the samples has been investigated during almostone year. In most cases, the odour retention of untreated textiles towards the substratesdid not persist over one or two weeks. By contrast, most of the treated sampleskept smelling one year after the beginning of the experiment. We observed that theuse of polyacrylic acid as crosslinking agent was less effective than citric andbutanetetracarboxylic acids. The efficiency of the different CDs varied in the order-CD > -CD > -CD, and the durability of the fragranteffect was directly dependent on the amount of CD grafted onto the fabrics.     

An Integrable Chain and Bi-Orthogonal Polynomials

An integrable chain connected to the isospectral evolution of the polynomials of type R–I introduced by Ismail and Masson is presented. The equations of motion of this chain generalize the corresponding equations of the relativistic Toda chain introduced by Ruijsenaars. We study simple self-similar solutions to these equations that are obtained through separation of variables. The corresponding polynomials are expressed in terms of the Gauss hypergeometric function. It is shown that these polynomials are stable (up to shifts of the parameters) against Darboux transformations of the generalized chain.