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71.
Luciana R. Pires KassabMauricio Eiji Camilo Ali H. Reshak K.J. Plucinski 《Materials Letters》2011,65(10):1445-1447
We have observed substantial influence of the illumination by 3.5 μs CO2 laser on the piezooptical coefficients of 59 PbO - 41 GeO2 (in wt.%) glasses prepared with Tm2O3, Er2O3, Yb2O3 using the following concentrations (in wt.%): B-Tm2O3 (0.5)/Yb2O3 (1.0)/Er2O3(0.5); C-Tm2O3(0.5)/Yb2O3(1.0)/Er2O3 O(1.0); D-Tm2O3 (0.5)/Yb2O3 (1.0)/Er 2O3 (2.0). We have found that the maximal changes were observed for B samples that contain the lowest concentration of Er2O3. The maximal changes are observed around 360 nm near the fundamental absorption edge. There exists some correlation between the maximal intensities of the photoluminescence and the maximal piezooptical changes. The CO2 lasers cause preliminary photothermal changes. The existence of the maxima may be caused by a competition between the phonon and anharmonic phonon subsystems, which are very sensitive to the temperature. 相似文献
72.
Laise Maia Lopes Gabriel Yoshiaki Ottaiano Luciana de Souza Guedes Mariana Agostini de Moraes Marisa Masumi Beppu 《应用聚合物科学杂志》2024,141(19):e55343
Mucin, a glycoprotein with viscoelastic properties, and silk fibroin, a protein excreted from silkworms with properties of thermal and mechanical resistance, have been probed as building blocks in the design of biomaterials. Aiming to evaluate the interaction and miscibility between mucin and fibroin, we synthesized silk fibroin and mucin (SF/MU) blends for biomedical applications. The morphological analysis of the SF/MU blends showed the presence of two phases, suggesting a partial miscibility between the polymers. The degradation temperature of the SF/MU blends increased with an increase in the silk fibroin content, indicating that silk fibroin contributed to the thermal stability of the blends. The glass transition temperature of the SF/MU blends lay between the values of the pure polymers. The Fourier-transform infrared spectroscopy results pointed out that the interaction between fibroin and mucin occurred between the amine group of silk fibroin and mucin carboxyl and hydroxyl groups. The outcomes of this work provided essential information on the miscibility of the SF/MU blends. These findings will be critical for further studies with fibroin and mucin-based biomaterials, especially in mucoadhesive systems and wound healing applications. 相似文献
73.
M. Marinelli F. Mercuri U. Zammit F. Scudieri 《International Journal of Thermophysics》1998,19(2):595-601
The photopyroelectric technique has been used to measure simultaneously the specific heat, the thermal conductivity, and the thermal diffusivity of 9CB liquid crystal in the temperature range 35 to 60°C, where the sample undergoes a weakly first-order phase transition and a second-order one. Measurements of the anisotropy of the thermal conductivity have also been performed, and the data have been used to establish the order of the above-mentioned phase transitions. Pretransitional effects in the isotropic phase in the thermal diffusivity have been found, and they have been associated with similar effects reported for the specific heat. 相似文献
74.
Roberta Roesler Luciana G. Malta Luciana C. Carrasco Gláucia Pastore 《Journal of food science》2006,71(2):C102-C107
Annona crassiflora, known commonly as araticum, is an exotic tropical fruit consumed mainly by native people of the Brazilian Cerrado (2nd biggest biome of Brazil). In this study, pulp, seed, and peel of slight ripe and overripe fruits were extracted using ethanol and water. The extracts showed high content of total phenols and were screening for their potential as antioxidants using the in vitro model 1,1‐ dipheniyl‐2‐picryl hydrazyl (DPPH). The ethanol extracts of peel and seeds showed IC50 of 48.82 μg/mL and 31.14 μg/mL, respectively, for the slightly ripe fruits. As the ethanolic fractions of araticum showed the highest antioxidant activity, they were selected for testing of its effect on lipid peroxidation. The ethanolic extracts of slightly ripe fruits showed IC50 of 4.44 μg/mL, 1.72 μg/mL, and 8.62 μg/mL for the peel, seed, and pulp, respectively. This is the 1st report on the antioxidant properties of the extracts of araticum. Owing to these properties, the studies can be further extending to exploit them for their possible application as natural antioxidant for cosmetic, supplements, and functional ingredients for food products. 相似文献
75.
Maurizio Penco Luciana Sartore Fabio Bignotti Stefania Della Sciucca Vittorio Ferrari Paolo Crescini Salvatore D'Antone 《应用聚合物科学杂志》2004,91(3):1816-1821
The aim of this work was the development of materials to be used in the field of gas sensing for the detection of organic vapors. Conductive sensors were prepared with carbon black filled blends of poly(vinyl chloride) and diol‐terminated poly(?‐caprolactone), an oligomeric plasticizer. For comparison, blends with di(2‐ethylhexyl)phthalate, a traditional low‐molecular‐weight plasticizer, were also prepared. All sensors were tested upon exposure to different organic vapors. In general, the plasticizer content affected the response rates of the sensors, and a linear variation of the relative resistance with the analyte concentration was observed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1816–1821, 2004 相似文献
76.
77.
P. Calvani M. Capizzi P. Dore S. Lupi P. Maselli G. Paleologo G. Balestrino M. Marinelli E. Milani H. Berger P. Roy Y. -L. Mathis 《Journal of Infrared, Millimeter and Terahertz Waves》1993,14(2):251-263
The reflectivities of seven films belonging to the Bi-Sr-Ca-Cu-O family, with Tc ranging from 60 to 95 K, and of a single crystal of insulating Bi-Sr-Y-Cu-O, have been measured at room temperature in the normal phase. The optical conductivity has been analyzed in terms of Drude (D), mid-infrared (MIR), and charge-transfer (CT) contributions. As Tc increases, the spectral weight within the charge-transfer gap (D+MIR) increases. Meanwhile, the peak frequency of the MIR band moves towards the far-infrared and the optical conductivity becomes more similar to that of a “normal” metal. 相似文献
78.
Luciano Favretto Luciana Gabrielli Favretto 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1984,179(3):201-204
Summary The concentration of Cd, Hg and Pb in the soft part of mussels has been studied by means of bi-and multi-variate statistical approaches. In particular, the principal component analysis has been applied to study the association among these toxic metals in mussels sampled from the gulf of Trieste, which is a critical area as far as mercury pollution is concerned.
Mehrdimensionale Analyse der Daten einiger xenobiotischer Spurenmetalle in Miesmuscheln aus dem Golf von Triest
Zusammenfassung Der Gehalt von Cd, Hg und Pb in Miesmuschelfleisch wurde nach einer statistischen mehrdimensionalen Analyse untersucht. Besonders wurde die Hauptkomponentenanalyse zum Studium der Assoziationen dieser toxischen Metalle in Miesmuscheln angewandt. Die Miesmuschelproben stammten aus dem Golf von Triest, ein kritisches Gebiet für Quecksilberverunreinigungen.相似文献
79.
80.
Lockwood H. Etzold K.-F. Stockton T. Marinelli D. 《Quantum Electronics, IEEE Journal of》1974,10(7):567-569
The general structure of double-heterojunction diode lasers is shown to be consistent with the required geometry of the Shockley diode or p-n-p-n switch. When the two devices are combined in a single structure, there results an extremely simple source of high optical power (>0.5-W) pulses of very short duration (<10 ns) without the need for a complex external driver. In principle, pulse triggering and repetition rate are easily controlled, suggesting that the device has potential application in pulse-coded optical communication systems. 相似文献