Multiple phase transitions in the generalized Curie-Weiss model

The generalized Curie-Weiss model is an extension of the classical Curie-Weiss model in which the quadratic interaction function of the mean spin value is replaced by a more general interaction function. It is shown that the generalized Curie-Weiss model can have a sequence of phase transitions at different critical temperatures. Both first-order and second-order phase transitions can occur, and explicit criteria for the two types are given. Three examples of generalized Curie-Weiss models are worked out in detail, including one example with infinitely many phase transitions. A number of results are derived using large-deviation techniques.     

Die Synthese von 3β-Acetoxy-24-aza-24-desoxa-xysmalogenin,. Partialsynthetische Versuche in der Reihe der Herzgifte. 12. Mitteilung,

Synthesis of 3β-acetoxy-24-aza-24-desoxa-xymalogenin Starting from the pregnenolone-derivative 1 we report the synthesis of the possibly cardiac-active compound 24-aza-24-desoxa-xysmalogenin 15 .     

Triplet quantum yield determination by photosensitized oxygenation in the presence of heavy atom additives: Rhodamine B in methanol

Relative rates of heavy-atom-enhanced photosensitized ¹O₂-reactions may be used to determine φ^o_T of sensitizers in heavy-atom-free solutions. φ^o_T = 0.12 ± 0.02 is obtained for a 5·10^?5 M methanolic solution of Rhodamine B .     

Über rote farbstoffe, die sich vom 2-phenyl-imidazolon-4(5) ableiten

Aqueous solutions of glycyl-benzoyl-imide (I) become dark red on standing for several days or on heating. The red pigments are formed via 2-phenyl-imidazolone-4(5) (II), which can be trapped by reaction with benzaldehyde. Paper electrophoresis using a special buffer system enabled comparison with other red products described in the literature or synthetized otherwise by us. None of them proved to be identical with the “glyoxaline red” of Ruhemann and Stapleton.