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151.
Mellisho CD González-Barrio R Ferreres F Ortuño MF Conejero W Torrecillas A García-Mina JM Medina S Gil-Izquierdo A 《Journal of the science of food and agriculture》2011,91(12):2132-2139
BACKGROUND This study was designed to describe the phenolic status of lemon juice obtained from fruits of lemon trees differing in iron (Fe) nutritional status. Three types of Fe(III) compound were used in the experiment, namely a synthetic chelate and two complexes derived from natural polymers of humic and lignine nature. RESULTS All three Fe(III) compounds were able to improve the Fe nutritional status of lemon trees, though to different degrees. This Fe(III) compound effect led to changes in the polyphenol content of lemon juice. Total phenolics were decreased (~33% average decrease) and, in particular, flavanones, flavones and flavonols were affected similarly. CONCLUSION Iron‐deficient trees showed higher phenolic contents than Fe(III) compound‐treated trees, though Fe deficiency had negative effects on the yield and visual quality of fruits. However, from a human nutritional point of view and owing to the health‐beneficial properties of their bioavailable phenolic compounds, the nutritional quality of fruits of Fe‐deficient lemon trees in terms of phenolics was higher than that of fruits of Fe(III) compound‐treated lemon trees. Moreover, diosmetin‐6,8‐di‐C‐glucoside in lemon juice can be used as a marker for correction of Fe deficiency in lemon trees. Copyright © 2011 Society of Chemical Industry 相似文献
152.
D. Y. Torres Martínez R. Castanedo Pérez G. Torres Delgado O. Zelaya Angel 《Journal of Materials Science: Materials in Electronics》2011,22(6):684-689
In this work, we report the synthesis and the structural, optical and electrical properties of undoped tin oxide thin films
obtained by the sol–gel technique. The films have been prepared from a simpler precursor solution than other ones reported;
it is based on stannous chloride (SnCl2·2H2O), ethanol, glycerol and triethylamine. The films are deposited on glass slide substrates and sintered at temperatures in
the 300–550 °C range, in an open atmosphere. A second thermal treatment in vacuum is made in order to decrease the resistivity
of the films. The X-ray diffraction patterns show the tetragonal phase of SnO2 with a small preferential orientation in the (110) plane. All films show high optical transmission (~85%) and a direct band
gap value around of 3.8 eV. The minimum resistivity value, 2 × 10−1 Ohm-cm, is obtained for the films sintered at 300 and 350 °C and thermal treated in vacuum at 500 °C for 1 h. The decrease
of the resistivity with the thermal treatment in vacuum is associated with an increase in the oxygen vacancies concentration. 相似文献
153.
Single layers of dielectric spheres are an interesting system to study from the fundamental and applied points of view. In this paper we present a systematic study of the influence of structural disorder on the transmission spectra of arrangements of spheres of different compactness. Glass sphere (ε=7) planes were built and their transmission spectra in the microwave range measured. Transmission behavior of this system is highly tolerant to disorder. Even in completely disordered arrangements, there is a highly rejected band with the dips of the spectrum observable. These results suggest that the collective modes of the sphere planes are formed by weakly coupled Mie modes of the individual spheres, and this coupling is governed by the average distance among the spheres. Disorder tolerance allows simpler fabrication procedures where the position of the spheres does not need to be precisely controlled. 相似文献
154.
The use of a spatial heterodyne interferometer-based spectrometer (SHS) for Raman spectroscopy is described. The motivation for this work is to develop a small, rugged, high-resolution ultraviolet (UV) Raman spectrometer that is compatible with pulsed laser sources and that is suitable for planetary space missions. UV Raman is a particular technical challenge for space applications because dispersive (grating) approaches require large spectrographs and very narrow slits to achieve the spectral resolution required to maximize the potential of Raman spectroscopy. The heterodyne approach of the SHS has only a weak coupling of resolution and throughput, so a high-resolution UV SHS can both be small and employ a wide slit to maximize throughput. The SHS measures all optical path differences in its interferogram simultaneously with a detector array, so the technique is compatible with gated detection using pulsed lasers, important to reject ambient background and mitigate fluorescence (already low in the UV) that might be encountered on a planetary surface where samples are uncontrolled. The SHS has no moving parts, and as the spectrum is heterodyned around the laser wavelength, it is particularly suitable for Raman measurements. In this preliminary report we demonstrate the ability to measure visible wavelength Raman spectra of liquid and solid materials using an SHS Raman spectrometer and a visible laser. Spectral resolution and bandpass are also discussed. Separation of anti-Stokes and Stokes Raman bands is demonstrated using two different approaches. Finally spectral bandpass doubling is demonstrated by forming an interference pattern in both directions on the ICCD detector followed by analysis using a two-dimensional Fourier transform. 相似文献
155.
Iñaki ZalakainJose Angel Ramos Raquel FernandezHaritz Etxeberria Iñaki Mondragon 《Thin solid films》2011,519(6):1882-1885
Highly oriented pyrolitic graphite (HOPG) is a useful substrate to visualize epitaxial formation due to its crystallographic structure. The morphology of a poly(styrene-b-isoprene-b-styrene) block copolymer thin film on a HOPG substrate was investigated by atomic force microscopy. Block copolymer domains generated a morphology with triangular regularity. This arrangement was induced by the HOPG substrate structure due to van der Waals attraction between the HOPG π-conjugated system and aromatic ring of polystyrene domains. However, increasing the film thickness, the substrate effect on the surface morphology decreased. As a consequence, film surfaces showed the coexistence of different structures such as highly aligned cylinders and perforated lamellae. When film thickness exceeded a threshold value, the substrate did not have effect in the surface arrangements and the surface showed a similar morphology to that existing in bulk. 相似文献
156.
Javier Angel Ramírez Masferrer 《Mine Water and the Environment》2002,21(3):111-113
In southern Spain, coal seams typically contain pyrite. The mines there are characteristically contaminated by the presence
of diverse metals disolved in acidic water. An experimental passive system, containing an anoxic limestone draine, organic
matter and wetlands, was constructed to assess how best to inprove the water chemistry. The procedure we used is reported
on here so others can learn from what we did. 相似文献
157.
Bagley Shirley P.; Angel Ronald; Dilworth-Anderson Peggye; Liu William; Schinke Steven 《Canadian Metallurgical Quarterly》1995,14(7):632
Race. ethnicity. and cultural attitudes and practices are among the variables that influence health behaviors. including adaptive health behaviors. The following discussions highlight the important role of social conditions in shaping health behaviors and the central role of family in promoting health across the Asian, Hispanic. Native American, and African American ethnic groups. Factors that may lead to health-damaging behaviors are also discussed. The need for additional research that identifies correlations among physiological, social. and behavioral factors and health behaviors, as well as underlying mechanisms, is called for. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
158.
159.
Ronan Boulic Javier Varona Luis Unzueta Manuel Peinado Angel Suescun Francisco Perales 《Virtual Reality》2006,10(1):48-61
Despite its central role in the constitution of a truly enactive interface, 3D interaction through human full body movement has been hindered by a number of technological and algorithmic factors. Let us mention the cumbersome magnetic equipments, or the underdetermined data set provided by less invasive video-based approaches. In the present paper, we explore the recovery of the full body posture of a standing subject in front of a stereo camera system. The 3D position of the hands, the head and the center of the trunk segment are extracted in real-time and provided to the body posture recovery algorithmic layer. We focus on the comparison between numeric and analytic inverse kinematics approaches in terms of performances and overall quality of the reconstructed body posture. Algorithmic issues arise from the very partial and noisy input and the singularity of the human standing posture. Despite stability concerns, results confirm the pertinence of this approach in this demanding context. 相似文献
160.
A new approach to steady-state rolling, with and without force transmission, based on the boundary element method is presented. The proposed formulation solves the problem in a more general way than semi-analytical methods, with which it shares some approximations. The robustness and accuracy of the proposed method is reflected in the comparative analysis of the results obtained for three different types of rolling problems involving identical, dissimilar and tyred cylinders, respectively. 相似文献