C---H local modes in cyclobutene, part I: FTIR studies, 600 to 10000 cm–1

The vibrational structure of C---H stretching states in gas-phase cyclobutene was studied using FTIR spectroscopy in the range 700–9000 cm−1. The structure was modelled using two effective vibrational Hamiltonians, one for each type of C---H bond present, consisting of local mode basis functions subject to coupling with symmetrically equivalent bonds and to Fermi resonances with suitable low frequency vibrations. Best-fit model parameters were determined using least-squares routines and the model predictions are compared to the observed band positions and intensities. Some discussion is given of the relevance of the observed couplings to intramolecular vibrational redistribution (IVR) which results in the observation of statistical behaviour in cyclobutene isomerization induced by excitation of C---H stretching overtones in the visible region.

'Vocabuli d'autori e di scienze e di libri' (Conv. II xii 5): ercorsi sapienziali di Dante

Discusses the trasmission of biblical sapiential sources in a variery medieval contexts and discourses, to ultimately focus on Dante's works

An 11,600 year old communal structure from the Neolithic of southern Jordan

The authors present a new type of communal and monumental structure from the earliest Neolithic in western Asia. A complement to the decorated stone pillars erected at Göbekli Tepe in the north, ‘Wadi Faynan 16 Structure O75’ in the southern Levant is a ritualised gathering place of a different kind. It serves to define wider western Asia as an arena of social experiment in the tenth millennium BC, one in which community seems to take precedence over economy.