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By combining ultrastructural and histochemical approaches, the paraxial organs of Euscorpius tergestinus (syn. E. carpathicus; Scorpiones, Euscorpiidae) have been studied for the first time. The paraxial organs are symmetrical structures in the male genital system. They are located on each side of the mesosoma and end at the genital aperture. The paraxial organs have a glandular function. They are directly involved in the secretion of the two hemispermatophores, which are deposited in the glandular lumen. When the hemispermatophores are extruded, they constitute the spermatophore, which is involved in sperm transfer. The epithelium of the paraxial organs is complex, being either unistratified or pseudostratified. Moreover, in the different parts of the gland, such as at the pars bulbosa, the epithelium can show folds. In addition, the appearance of the epithelial cells varies with secretory activity. The cells deposit the different components of the hemispermatophore in the lumen. We show that the cells have two successive methods of secretion: firstly merocrine and then apocrine. This has never been described before. The histochemical observations of the hemispermatophore show its complex structure with the presence of different constituents.

Vibrational bands of each quinadridone pigment have been attributed in two mixtures: PO48 and PR206. The amounts of the PV19 and quinacridone quinone components have been estimated by preresonance Raman microspectrometry.

Heat capacity measurements and Raman spectra analysis of (NH4)3H(SO4)2 were performed between 10 and 130 K. Thermodynamics functions as well as structural and dynamic behaviour of the VII → V phase transition at 81.5 K have been specified. This phase transition is confirmed to be of the first order with ΔH = 444 J mol-1 and ΔS = 5.5 J K-1 mol-1. The mechanism appears as a reorientational ordering of ammonium ions which are the main responsible for the ferroelectricity rather than the proton engaged in the OH … O hydrogen bond.

Low-frequency Raman spectra (5-250 cm-1) of a polycrystalline sample of bis(n-propylammonium) lead tetrachloride were recorded at different temperatures between 4 and 300 K. A new first-order reentrant phase transition was observed near 35 K. The phase diagram is:[image omitted] Both phases II and IV present the same degree of disorder and are believed to be isomorphic with a monoclinic cell symmetry. Spectral evolution analysis and analogy with a manganese homologous compound suggest an incommensurate character for phase III between 35 K and 91 K. The pseudo-phase mode characteristic of the incommensurability was identified at about 10 cm-1

The Tieschitz H3 chondrite contains 0.25% bulk carbon1but concentrations of as much as 2–6% (ref. 2) occur in black, 10–20 µm-wide rims around chondrules that are thought to have accreted before the agglomeration of the stone2–5. These rims are extremely fine-grained and compact, the main constituent being an iron-rich olivine (Fa 60–65) as shown by a Debye–Sherrer X-ray diffractogram, in good agreement with the FeO/FeO + MgO matrix value2,6. To further our understanding of the rim composition and of the thermal history of the stone, we used the MOLE Raman laser microprobe7to characterize the carbon constituent. We report here that it is a highly disordered graphite with a progressive ordering as shown by samples heated to temperatures between 300 and 600 °C. Tieschitz could not have been heated to more than 300–350 °C.

THE AH stretching band of a strongly hydrogen bonded AH..Bsystem is usually very broad and may present a complicated structure consisting of numerous sub-bands. In order to explain these sub-bands, the frequency modulation theory—that is, that the sub-band frequencies can be represented, by the expression ν = νAH±nν(AH)..B, where n= 0,1,2… and ν(AH)..Bis any hydrogen bond frequency—has been advanced in the literature1–3. In the case of imidazole, which contains strong NH..N hydrogen bonds, we have suggested that the hydrogen bond-frequencies do not seem to be a decisive factor in determining the sub-band structure of the νNH absorption4. In this communication, we wish to show that the same is true for purine, which contains a similar hydrogen bonded system, by comparing the behaviour of the νNH sub-bands and the far infrared hydrogen bond frequencies of different isotopic species at different temperatures.