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Rui P. Queirós Daniel Rainho Mauro D. Santos Liliana G. Fidalgo Ivonne Delgadillo 《高压研究》2015,35(1):69-77
This study evaluated high pressure processing (P1 – 400?MPa/5?min; P2 – 550?MPa/2?min) and thermal pasteurization (TP – 70°C/30?s) effects on sweet cherry juice's microbiological and physicochemical parameters, during four weeks of refrigerated storage. All treatments reduced the microbiological load to undetectable levels not affecting total soluble solids and titratable acidity. The pH increased with all treatments, however, it decreased during storage. Phenols were differently affected: TP increased them by 6%, P1 had no effect while P2 decreased them by 11%. During storage, phenols in control and TP samples decreased by 26% and 20%, P1 samples decreased them by 11% whereas P2 showed no variation. TP had no effect on anthocyanins, while pressure treatments increased them by 8%. Anthocyanins decreased during storage, particularly in the control and P1 (decreasing 41%). All treatments had no effect on antioxidant activity until the 14th day, thereafter high pressure processing samples showed the highest antioxidant activity. 相似文献
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J.P. Rainho Z. Lin J. Rocha L.D. Carlos 《Journal of Sol-Gel Science and Technology》2003,26(1-3):1005-1009
The sol-gel synthesis and structural characterisation of narsarsukite powders are reported. Samples doped with different Eu3+ amounts (Ti/Eu = 20 and 200), calcined at 800°C, have been characterised by powder XRD, 23Na, 29Si MAS NMR, Raman and luminescence spectroscopies. Eu3+-doped narsarsukite displays a high and stable room-temperature luminescence. The presence in narsarsukite of two different Eu3+ local environments is inferred based both on the distinct 5D0 7F0 lines observed and on the local field splitting of the 7F1,2 levels. For low lanthanide contents, the Eu3+ ions are essentially localised in a centrosymmetric environment characterized by a low-energy 5D0 7F0 line and a relatively long 5D0 lifetime (3.56–3.96 ms). In contrast, at high lanthanide contents the Eu3+ ions are also present in a second local site with a less covalent first coordination shell. This corresponds to a high-energy 5D0 7F0 line and a short 5D0 lifetime (0.84–0.99 ms). Therefore, it is likely that Eu3+ ions substitute for both Ti4+ and Na+, although the former ions are preferentially replaced at low Eu3+ content. 相似文献
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The structural and electronic transport properties of La1−x
Ce
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MnO3 (x=0.0–1.0) have been studied. All the samples exhibit orthorhombic crystal symmetry and the unit cell volume decreases with
Ce doping. They also make a metal-insulator transition (MIT) and transition temperature increases with increase in Ce concentration
up to 50% doping. The system La0.5Ce0.5MnO3 also exhibits MIT instead of charge-ordered state as observed in the hole doped systems of the same composition. 相似文献
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Jérôme JP. Leon 《Letters in Mathematical Physics》1981,5(1):75-80
We establish a transformation which connects the potentials of the one-dimensional Dirac and Klein-Gordon operators. This transformation links the solutions of the nonlinear evolution equations solvable by means of the two inverse spectral transforms which use the Dirac and Klein-Gordon direct and inverse spectral problems. 相似文献