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排序方式: 共有1621条查询结果,搜索用时 15 毫秒
991.
Maietti A Tedeschi P Stagno C Bordiga M Travaglia F Locatelli M Arlorio M Brandolini V 《Journal of food science》2012,77(6):C646-C652
Two morphologically different cultivars of Italian melons (Baggio and Giusto) were characterized considering samples harvested in different times, at the beginning (BPP) and at the end of the physiological plant production period (EPP). Proximate composition, protein, minerals, pH, phenolic content, antioxidant capacity, ascorbic acid, carotenoids, condensed tannins, and flavonoids were measured, showing a significant decrease in EPP samples (phenolics, antioxidant capacity, condensed tannins, and flavonoids); ascorbic acid decreased in Giusto cv, carotenoids in Baggio cv. Mineral content increased in either the cultivars (EPP samples). Year-to-year difference was significantly highlighted; the plant growing cycle significantly affected the chemotype. Despite these effects, the Principal Component Analysis (PCA) permitted the discrimination of Baggio from Giusto cv, and the discrimination of BPP from EPP samples as well. 相似文献
992.
Marisa Di Matteo Donatella Albanese Loredana Liguori 《Food and Bioprocess Technology》2012,5(4):1416-1421
The paper proposes an improved peeling treatment for hazelnut fruits consisting in dipping them in a solution (NaOH 0.4 g/100 g,
NaH2PO4·H2O 0.2 g/100 g) for 10 min at 50 °C, then scrubbing them with rubber rollers. The effects of the treatment on quality and peeling
of four Italian hazelnut varieties were investigated. The data collected on peeling capability showed that the treatment proposed
was effective in cuticle removal with a yield of peeling higher than 90%. The comparison of chemical–physical parameters in
unpeeled and peeled hazelnut samples highlights that no difference was detected in texture, sugar, protein and α-tocopherol
values. After the peeling process a significant change (p < 0.05) in colour, total fat and peroxide value was observed in peeled hazelnut samples when compared with the unpeeled ones.
With regard to the sensorial parameters, no significant changes were found between unpeeled and peeled hazelnut samples. The
peeling solution proposed in this study shows a good potential in industrial applications as an alternative to the usual manufacturing
peeling method (roasting) that causes changes, not always desired, to some sensorial and chemical–physical parameters of the
fresh fruit. 相似文献
993.
Warapong Krengvirat Srimala Sreekantan Ahmad-Fauzi Mohd Noor Nobuaki Negishi Song Yul Oh Go Kawamura Hiroyuki Muto Atsunori Matsuda 《International Journal of Hydrogen Energy》2012
Carbon-incorporated titanium dioxide (TiO2) photoelectrodes with different structural features were prepared via rapid-anodic oxidation under different electrical potentials and exposure times. The interstitial carbon arising from the pyrogenation of ethylene glycol electrolytes induced a new C2p occupied state at the bottom of the conduction band, which lowered the band gap energy to ∼2.3 eV and consequently enabled the visible-light responsiveness. Photoelectrodes with nanotubular structures provided higher photoconversion efficiency (η) and hydrogen (H2) evolution capability than those with irregular structures. The increased aspect ratio, wall thickness, and pore size of the nanotube arrays contributed to η through greater photon excitation and penetration. However, this contribution is limited by the high recombination of the charge carriers at ultra-high aspect ratios. Photoelectrodes with a nanotube length of ∼19.5 μm, pore size of ∼103 nm, wall thickness of ∼17 nm, and aspect ratio of ∼142.5 exhibited remarkable capability to generate H2 at an evolution rate of up to ∼508.3 μL min−1 cm−2 and η of ∼2.3%. 相似文献
994.
Oliveri G Randazzo A Pastorino M Massa A 《Journal of the Optical Society of America. A, Optics, image science, and vision》2012,29(6):945-958
We introduce a new imaging technique that integrates the inexact Newton method into a multifocusing scheme within the contrast-source formulation of the inverse scattering problem. Representative results from an extensive validation concerned with both synthetic and experimental scattering data are reported to assess, also through comparisons, advantages and limitations of the proposed approach in terms of accuracy, robustness, and computational efficiency. 相似文献
995.
S Lizzit R Larciprete P Lacovig M Dalmiglio F Orlando A Baraldi L Gammelgaard L Barreto M Bianchi E Perkins P Hofmann 《Nano letters》2012,12(9):4503-4507
High-quality, large-area epitaxial graphene can be grown on metal surfaces, but its transport properties cannot be exploited because the electrical conduction is dominated by the substrate. Here we insulate epitaxial graphene on Ru(0001) by a stepwise intercalation of silicon and oxygen, and the eventual formation of a SiO(2) layer between the graphene and the metal. We follow the reaction steps by X-ray photoemission spectroscopy and demonstrate the electrical insulation using a nanoscale multipoint probe technique. 相似文献
996.
Song-yul Oh Keisuke Kawai Go Kawamura Hiroyuki Muto Atsunori Matsuda 《Materials Research Bulletin》2012,47(10):2931-2935
Anhydrous proton conductive MHSO4–H4SiW12O40 (MHS–STA) composites were successfully synthesized using mechanochemical treatment. 80MHS·20STA (mol%) composite, for example, showed very high anhydrous proton conductivity above 10?3 S cm?1 in a temperature range from 160 to 60 °C under ambient pressure. From the X-ray diffraction study, it was confirmed that the mechanochemical treatment induced chemical interactions via ion-exchange between M+ ion in MHS and H+ ion in STA. Furthermore, phase-transition of raw substances, such as melting, dehydration and superprotic phase-transition, was suppressed in mechanochemically synthesized MHS–STA composites, indicating that improvement of anhydrous proton conductivity for MHS–STA composites is caused by the changes in protic conduction behavior. 相似文献
997.
Rossella F Soldano C Bellani V Tommasini M 《Advanced materials (Deerfield Beach, Fla.)》2012,24(18):2453-2458
Metal-filled carbon nanotubes represent a novel class of photothermal nanomaterials: when illuminated by visible light they exhibit a strong enhancement of the temperature at the metal sites, due to the enhanced plasmonic light absorption at the metal surface, which behaves as a heat radiator. Potential applications include nanomedicine, heat-assisted magnetic recording, and light-activated thermal gradient-driven devices. 相似文献
998.
Maria Laura Bolognesi Prof. Hoang Ngoc Ai Tran Matteo Staderini Alessandra Monaco Alberto López‐Cobeñas Salvatore Bongarzone Xevi Biarnés Dr. Pilar López‐Alvarado Nieves Cabezas Maria Caramelli Dr. Paolo Carloni Prof. J. Carlos Menéndez Prof. Giuseppe Legname Prof. 《ChemMedChem》2010,5(8):1324-1334
Prion diseases are fatal neurodegenerative and infectious disorders for which effective pharmacological tools are not yet available. This unmet challenge and the recently proposed interplay between prion diseases and Alzheimer's have led to a more urgent demand for new antiprion agents. Herein, we report the identification of a novel bifunctional diketopiperazine (DKP) derivative 1 d , which exhibits activity in the low micromolar range against prion replication in ScGT1 cells, while showing low cytotoxicity. Supported by properly addressed molecular modeling studies, we hypothesized that a planar conformation is the major determinant for activity in this class of compounds. Moreover, studies aimed at assessing the mechanism‐of‐action at the molecular level showed that 1 d might interact directly with recombinant prion protein (recPrP) to prevent its conversion to the pathogenic misfolded prion protein (PrPSc)‐like form. This investigation suggests that DKP based antiprion compounds can serve as a promising lead scaffold in developing new drugs to combat prion diseases. 相似文献
999.
Valerio Di Lecce Michele Esposto Matteo Bonaiuti Gaudenzio Meneghesso Enrico Zanoni Fausto Fantini Alessandro Chini 《Microelectronics Reliability》2010,50(9-11):1523-1527
In this paper, the degradation of AlGaN/GaN high-electron mobility transistors (HEMTs) is investigated by means of dc stresses performed on fresh devices either on the gate-drain junction only (i.e., with the source terminal floating) or on the gate-source junction only (i.e., with the drain terminal floating). In both cases step-stresses were carried out by increasing VDG and VSG respectively up to 35 V: the saturated drain current decreased in both cases, and a significant increase in the output conductance was found for the drain-stressed devices, whereas it was negligible for the source-stressed devices. The reason for these different behaviors was believed to be the creation of acceptor traps in the AlGaN layer underneath the stressed side of the gate junction, their influence being different in the two cases because of the high horizontal electric field at the drain end of the gate during on-state operation. We carried out numerical simulations showing that the presence of a defective region with an acceptor trap concentration underneath the gate-drain or gate-source junction fits our hypothesis. 相似文献
1000.
Yagang Feng Guido Toci Angela Pirri Barbara Patrizi Zewang Hu Jiabei Wei Hongming Pan Xing Zhang Xiaoying Li Sha Su Matteo Vannini Jiang Li 《Journal of the American Ceramic Society》2020,103(1):224-234
Transparent Yb:Y3ScAl4O12 (Yb:YSAG) ceramics with different ytterbium doping concentrations such as 5, 10, 15, 20 at.% have been successfully fabricated by solid-state reactive sintering. All the obtained ceramics are in dense and homogeneous structure after sintering at 1820°C for 30 hours and with a posttreatment by hot isostatic pressing at 1750°C for 3 hours with 200 MPa pressure. We systematically analyzed the influence of Yb3+ doping concentration on the microstructure and optical properties of the ceramics. The 10 at.% Yb:Y3ScAl4O12 ceramics with a thickness of 3.2 mm show the best transparency as high as 80.9% at 1100 nm. The laser emission of the 10 at.% Yb:YSAG ceramics was tested, resulting in a maximum slope efficiency of 67.6% and a maximum output power of 11.3 W under quasi-continuous wave pump conditions. The tuning range spanned from 990 to 1071 nm. 相似文献