Search

The objective of this communication is to make a review of the evolution, in the last 10 years, in the field of the Web information retrieval. With the implantation of the different cybermetrics techniques the evolution from the studies of the Web has been spectacular and is at the moment an inexhaustible field of study. [ABSTRACT FROM AUTHOR]

The jet-cooled rotational spectrum of uracil has been investigated using laser ablation molecular beam Fourier transform microwave (LA-MB-FTMW) spectroscopy. The quadrupole structure originated by the two 14N nuclei of uracil has been completely resolved and assigned. This provides a definitive method to establish the pyrrolic or pyrimidinic nature of the N nuclei and allows us to conclude that the observed tautomer of uracil in the gas phase is the diketo form. From the rotational constants of the isotopic species detected, a structure of uracil has been determined. [ABSTRACT FROM AUTHOR]