The Graeco-Roman harbor of Neapolis (Naples, Italy), chronologically constrained between the late 4th century BC and the 6th century AD, offers a unique sight on relationship between past and present into the history ...The Graeco-Roman harbor of Neapolis (Naples, Italy), chronologically constrained between the late 4th century BC and the 6th century AD, offers a unique sight on relationship between past and present into the history of the marine biodiversity. In fact, the digs expose fossil leaf of Posidonia oceanica with epiphytic communities of microorganisms. Posidonia oceanica is a seagrass endemic to theMediterraneanthat forms large meadows whose remains can persist in the sediment for thousands of years. In this communication, we report results of analyses carried out using both molecular and morphological techniques on sub-fossil leaves of P. oceanica and their associated epiphytic communities.展开更多
Lutetium β-tricalcium phosphate Ca9Lu（PO4）7 was synthesized by solid-state reaction at 1200 ℃, and investigated by means of a combination of scanning electron microscopy （SEM） equipped with energy dispersive X-r...Lutetium β-tricalcium phosphate Ca9Lu（PO4）7 was synthesized by solid-state reaction at 1200 ℃, and investigated by means of a combination of scanning electron microscopy （SEM） equipped with energy dispersive X-ray spectroscopy （EDS）, X-ray diffraction （XRD）, Fourier transform infrared （FTIR） and Raman spectroscopies. SEM morphological analysis reveals the presence of sub spherical and prismatic micro crystalline aggregates, while EDS semi-quantitative analysis confirms the nominal Lu/Ca compo- sition. The unit cell and the space group were determined by X-ray powder diffraction data showing that the compound crystallizes in the rhombohedral R3c wfiitlockite-type structure, with unit cell constants a - b 1.04164（1） nm, c 3.7302（1） nm and cell volume V 3.5051（1） nm^3. The investigation was completed with the structural refinement by the Rietveld method, and discussion of the distribution of Lu within cationic sites according to the results of the Rietveld refinement. The FIIR and Raman spectra, correlated to isostructural rare earth phosphates from literature, show slight band shifts of the phosphate modes correlated to the evolving size of the rare earth elements.展开更多
文摘The Graeco-Roman harbor of Neapolis (Naples, Italy), chronologically constrained between the late 4th century BC and the 6th century AD, offers a unique sight on relationship between past and present into the history of the marine biodiversity. In fact, the digs expose fossil leaf of Posidonia oceanica with epiphytic communities of microorganisms. Posidonia oceanica is a seagrass endemic to theMediterraneanthat forms large meadows whose remains can persist in the sediment for thousands of years. In this communication, we report results of analyses carried out using both molecular and morphological techniques on sub-fossil leaves of P. oceanica and their associated epiphytic communities.
基金Project partially supported by CNR(Italy)-CNRST(Morocco) Bilateral Project "Novel Ca_9RE(PO_4)_7 biomaterials:synthesis and multi-methodological characterization via X-ray techniques" reference CNR 1588/16
文摘Lutetium β-tricalcium phosphate Ca9Lu（PO4）7 was synthesized by solid-state reaction at 1200 ℃, and investigated by means of a combination of scanning electron microscopy （SEM） equipped with energy dispersive X-ray spectroscopy （EDS）, X-ray diffraction （XRD）, Fourier transform infrared （FTIR） and Raman spectroscopies. SEM morphological analysis reveals the presence of sub spherical and prismatic micro crystalline aggregates, while EDS semi-quantitative analysis confirms the nominal Lu/Ca compo- sition. The unit cell and the space group were determined by X-ray powder diffraction data showing that the compound crystallizes in the rhombohedral R3c wfiitlockite-type structure, with unit cell constants a - b 1.04164（1） nm, c 3.7302（1） nm and cell volume V 3.5051（1） nm^3. The investigation was completed with the structural refinement by the Rietveld method, and discussion of the distribution of Lu within cationic sites according to the results of the Rietveld refinement. The FIIR and Raman spectra, correlated to isostructural rare earth phosphates from literature, show slight band shifts of the phosphate modes correlated to the evolving size of the rare earth elements.
