RESUMEN
OBJECTIVE: To explore how to remove CT ring-shaped artifact quickly and effectively, and to improve accuracy of CT reconstruction image. METHODS: CT graphics (including the ring-shaped artifacts) were used first in coordinate transformation with a new transformation method. A two-dimensional filter was designed to filter the image. Then, a one-dimensional filter was used to re-filter the image. Finally, a new transform method was used to restore the image. RESULTS: The two-step coordinate transformation of ring-shaped artifact algorithm resulted in accurate restored original CT image, effectively reducing its interference on useful information. CONCLUSION: The method described in this study can overcome disadvantages of existing methods and obtain good results.
Asunto(s)
Artefactos , Procesamiento de Imagen Asistido por Computador , Tomografía Computarizada por Rayos X , AlgoritmosRESUMEN
A "basophilic method" for phenolic hydroxyl bridged lanthanide coordination polymers (CPs) was developed. With this method, eleven CPs with the general formula of [Ln(HL1)L1·H(2)O](n) (Ln = Tb (1), Nd (2), Eu (3), Gd (4), La (5), Er (6), Y (7), H(2)L1 = 4-methyl salicylic acid) and [Ln(HL2)L2·2MeOH](n) (Ln = Eu (8), Tb (9), Gd (10), La (11), H(2)L2 = 3-hydroxy-2-naphthoic acid) were synthesized based on two ligands, and five of them (1-4 and 8) were characterised by X-ray single crystal diffraction. The powder X-ray diffraction patterns (PXRD) of complexes showed that 1-7 are isostructural, 8-11 are isostructural. Furthermore, 1 was characterised by Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), differential thermal analysis (DTA), elemental analysis (EA), one and two photon luminescence were investigated in detail.
Asunto(s)
Complejos de Coordinación/química , Elementos de la Serie de los Lantanoides/química , Fenoles/química , Complejos de Coordinación/síntesis química , Cristalografía por Rayos X , Concentración de Iones de Hidrógeno , Ligandos , Mediciones Luminiscentes , Conformación Molecular , FotonesRESUMEN
The first complex picosecond filament, namely a filament of terbium(III) p-hydroxybenzoate, is observed. The filament is the only example of Ln(III) ion two-photon absorption in a complex. A transparent, colorless and mechanically robust thin film, as well as a supramolecular gel, of this complex are prepared in a facile manner and exhibit strong luminescence. The thin film is characterized in detail by XRD, SEM, UV-vis, luminescence spectroscopy and lifetime.