A B\"acklund transformation for elliptic four-point conformal blocks

We apply an integral transformation to solutions of a partial differential equation for five-point correlation functions in Liouville theory on a sphere with one degenerate field $V_{-\frac{1}{2b}}$. By repeating this transformation, we can reach a whole lattice of values for the conformal dimensions of the four other operators. Factorizing out the degenerate field leads to integral representations of the corresponding four-point conformal blocks. We illustrate this procedure on the elliptic conformal blocks discovered in a previous publication.Comment: 9 pages, to be published in the Memorial Volume for Ludwig Faddee

Convergent sequences of perturbative approximations for the anharmonic oscillator II. Compact time approach

We present an alternative pathway in the application of the variation improvement of ordinary perturbation theory exposed in [1] which can preserve the internal symmetries of a model by means of a time compactification.Comment: 21 pages, 4 Postscript figures available through anonymous ftp at ftp://algol.lpm.univ-montp2.fr ; replaces version which could not be postscripted presumably for lack of figures.uu fil

Convergent sequences of perturbative approximations for the anharmonic oscillator I. Harmonic approach

We present numerical evidence that a simple variational improvement of the ordinary perturbation theory of the quantum anharmonic oscillator can give a convergent sequence of approximations even in the extreme strong coupling limit, the purely anharmonic case. Some of the new techniques of this paper can be extended to renormalizable field theories.Comment: 29 pages, 12 Postscript figures available through anonymous ftp at ftp://algol.lpm.univ-montp2.fr ; replaces earlier version which could not be postscripted presumably due to lack of figures.uu fil

Applications of high pressure differential scanning calorimetry to aviation fuel thermal stability research

High pressure differential scanning calorimetry (DSC) was studied as an alternate method for performing high temperature fuel thermal stability research. The DSC was used to measure the heat of reaction versus temperature of a fuel sample heated at a programmed rate in an oxygen pressurized cell. Pure hydrocarbons and model fuels were studied using typical DSC operating conditions of 600 psig of oxygen and a temperature range from ambient to 500 C. The DSC oxidation onset temperature was determined and was used to rate the fuels on thermal stability. Kinetic rate constants were determined for the global initial oxidation reaction. Fuel deposit formation is measured, and the high temperature volatility of some tetralin deposits is studied by thermogravimetric analysis. Gas chromatography and mass spectrometry are used to study the chemical composition of some DSC stressed fuels

De Guillaume Postel à Richard Simon : Zohar et autres sources hébraïques de G. Postel dans les collections de la Bibliothèque municipale de Rouen

La Bibliothèque municipale de Rouen conserve six volumes d’éditions hébraïques du XVIe s. qui ont appartenu à Guillaume Postel avant d’entrer dans la bibliothèque rabbinique de Richard Simon, aujourd’hui réunie aux collections publiques rouennaises. Ces ouvrages constituent d’importants témoignages de l’activité de Postel hébraïsant. Le plus remarquable d’entre eux est un Zohar dans l’édition de Crémone, l’exemplaire même utilisé par Postel pour sa seconde traduction réalisée entre 1562 et 1569. D’autres volumes, édités par Bomberg, comptent parmi les sources juives les plus souvent citées par Postel, et font partie des textes découverts et étudiés par celui-ci pendant son séjour à Venise de 1546-1548 : Midrašim (avec les Rabbot publiés en 1545 d’une part, et le Midraš sur les Psaumes, Samuel et les Proverbes, de 1546, d’autre part ) et Commentaire de Bahya ben Ašer ben Halawa, de 1546 également. La BMR possède, outre le Zohar, un deuxième témoin de la bibliothèque hébraïque de Postel pendant son séjour à Saint-Martin-des-Champs, avec la compilation talmudique Ein/Bet Israel de Jacob ben Salomon ibn Habib (1566), acquisition qui semble dictée par sa préoccupation pour le Talmud. Enfin, il faut ajouter à cet ensemble le code de Maïmonide Mišne Torah (1551), ouvrage de référence sans doute, mais aussi le seul parmi les exemplaires de Rouen qui ne semble guère avoir nourri la réflexion de Postel. En effet, tous les autres textes, à caractère allégorique, ont constamment inspiré Postel, qui, au fil des ans, en a couvert les marges d’annotations où l’on retrouve tous les thèmes de sa mythologie

La Vita Christi du Pseudo-Bonaventure et un ‘lectionnaire' en français

Étude de deux incunables en langue française conservés en exemplaire unique à la BM de Rouen, remarquables tant par leur impression que par leur contenu. Issus d\u27un atelier inconnu (Paris ou Centre-Ouest, c. 1485-1490 ?), ces deux textes constituent la seule édition imprimée connue à ce jour de deux traductions médiévales, les Meditationes Vitae Christi du pseudo-Bonaventure, et le lectionnaire, ou Epîtres et Evangiles, de Jean de Vignay. Ces ouvrages proviennent de la collection de Nicolas de La Place, abbé du Val-Richer († 1649

Classer les livres selon le Système figuré des connaissances humaines : émergence et déclin des systèmes bibliographiques d’inspiration baconienne (1752-1812). 1ère partie

During the second half of the 18th Century the Système figuré des connaissances humaines inspired several bibliographies which attempted to re-found their discipline scientifically by replacing the usual system used to classify books with a new bibliographical system inspired by Diderot and d’Alembert’s diagram based on Bacon. The idea was launched by the bookseller David, one of the publishers of the Encyclopédie, in the article \u27Catalogue\u27 (vol. II). But it took some time to be applied despite two attempts, under the patronage of abbé de Montlinot in 1760 and then by the Metz Academy, around 1765. But this Encyclopedic-Baconian project, which went into a decline in France during the 1770s and 1780s, was taken up abroad. Around 1780, Thomas Jefferson developed from the Système figuré his own system of classification which had a great success in the U.S.A. In addition, as he represented his country in Paris from 1785 to 1789, he influenced bibliographical reflection in France and contributed to the brief upsurge in Baconian classifications at the turn of the 18th-19th centuries, which will be studied in a sequel to this article - See more at: http://rde.revues.org/5047#sthash.Ehhoyesq.dpuf