Intermediate motions and dipolar couplings as studied by Lee-Goldburg cross-polarization NMR: Hartmann-Hahn matching profiles

In this article, we evaluate the use of simple Lee-Goldburg cross-polarization (LG-CP) NMR experiments for obtaining quantitative information of molecular motion in the intermediate regime. In particular, we introduce the measurement of Hartmann-Hahn matching profiles for the assessment of heteronuclear dipolar couplings as well as dynamics as a reliable and robust alternative to the more common analysis of build-up curves. We have carried out dynamic spin dynamics simulations in order to test the method's sensitivity to intermediate motion and address its limitations concerning possible experimental imperfections. We further demonstrate the successful use of simple theoretical concepts, most prominently Anderson-Weiss (AW) theory, to analyze the data. We further propose an alternative way to estimate activation energies of molecular motions, based upon the acquisition of only two LG-CP spectra per temperature at different temperatures. As experimental tests, molecular jumps in imidazole methyl sulfonate, trimethylsulfoxonium iodide, and bisphenol A polycarbonate were investigated with the new method.

Contribuição ao conhecimento do gênero Zelurus Hahn (Spiniger auct. ) (Reduviidae, Hemiptera)

In the present paper the authors describe the male and female genitalia of various species of Zelurus (=Spiniger). There were not always obtained reliable specific characters, specially in nearly related species. Futhermore there were studied 59 species and subspecies, from Dutch Guiana, Brazil, Peru, Bolivia and Argentine. New locality records and synonymic notes are given and some allotypes are designated. Eight species and two subspecies, from Brazil and Argentine, proved to new to science.

Estudo comparativo da genitália externa masculina de duas espécies de Zelurus Hahn, 1826 (Hemiptera, Reduviidae, Reduviianae)

Objetivando estabelecer novos parâmetros taxonômicos para o gênero Zelurus Hahn, 1826, foi feito um estudo detalhado e comparativo da genitália externa dos machos de duas espécies: Z. circumcinctus (Hahn, 1835) lepeletierianus (Kirdaldy, 1909). Foram evidenciadas como mais representativas as seguintes estruturas fálicas: processo do pigóforo, parâmetro, falosoma, suporte do falosoma e processo 2 do endosoma.

Le devin du village. L'amour ne sait guère / J.J. Rousseau, comp.. Bois épais : [extrait d'"Amadis"] / Lully, comp. ; Reynaldo Hahn, BAR, p

Titre uniforme : [Le devin du village]. Extrait