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991.
Antonio Cirillo Matteo Mancini Domenico Giuliano Pasquale Sodano 《Nuclear Physics B》2011,852(1):235-268
We use boundary field theory to describe the phases accessible to a tetrahedral qubit coupled to Josephson junction chains acting as Tomonaga-Luttinger liquid leads. We prove that, in a pertinent range of the fabrication and control parameters, an attractive finite coupling fixed point emerges due to the geometry of the composite Josephson junction network. We show that this new stable phase is characterized by the emergence of a quantum doublet which is robust not only against the noise in the external control parameters (magnetic flux, gate voltage) but also against the decoherence induced by the coupling of the tetrahedral qubit with the superconducting leads. We provide protocols allowing to read and to manipulate the state of the emerging quantum doublet and argue that a tetrahedral Josephson junction network operating near the new finite coupling fixed point may be fabricated with today?s technologies. 相似文献
992.
993.
994.
The existence of non-trivial solutions for nonlinear Dirichlet problems involving the p-Laplacian is investigated. In particular, an existence result of at least one non-trivial solution, without requiring any asymptotic condition on the nonlinear term either at zero or at infinity, is presented. As a consequence, also a multiplicity result is pointed out. The approach is based on a local minimum theorem for differentiable functionals. 相似文献
995.
Santina Chiechio Magda Zammataro Massimo Barresi Margherita Amenta Gabriele Ballistreri Simona Fabroni Paolo Rapisarda 《Molecules (Basel, Switzerland)》2021,26(14)
Citrus fruits are a rich source of high-value bioactive compounds and their consumption has been associated with beneficial effects on human health. Red (blood) oranges (Citrus sinensis L. Osbeck) are particularly rich in anthocyanins (95% of which are represented by cyanidin-3-glucoside and cyanidin-3-6″-malonyl-glucoside), flavanones (hesperidin, narirutin, and didymin), and hydroxycinnamic acids (caffeic acid, coumaric acid, sinapic, and ferulic acid). Lemon fruit (Citrus limon) is also rich in flavanones (eriocitrin, hesperidin, and diosmin) and other polyphenols. All of these compounds are believed to play a very important role as dietary antioxidants due to their ability to scavenge free radicals. A standardized powder extract, red orange and lemon extract (RLE), was obtained by properly mixing anthocyanins and other polyphenols recovered from red orange processing waste with eriocitrin and other flavanones recovered from lemon peel by a patented extraction process. RLE was used for in vivo assays aimed at testing a potential beneficial effect on glucose and lipid metabolism. In vivo experiments performed on male CD1 mice fed with a high-fat diet showed that an 8-week treatment with RLE was able to induce a significant reduction in glucose, cholesterol and triglycerides levels in the blood, with positive effects on regulation of hyperglycemia and lipid metabolism, thus suggesting a potential use of this new phytoextract for nutraceutical purposes. 相似文献
996.
997.
We present three new copositivity tests based upon difference-of-convex (d.c.) decompositions, and combine them to a branch-and-bound algorithm of ω-subdivision type. The tests employ LP or convex QP techniques, but also can be used heuristically using appropriate test points. We also discuss the selection of efficient d.c. decompositions and propose some preprocessing ideas based on the spectral d.c. decomposition. We report on first numerical experience with this procedure which are very promising. 相似文献
998.
Diego M. Díaz Pace Norberto A. Gabriele Mayra Garcimuño Cristian A. D'Angelo Graciela Bertuccelli Daniela Bertuccelli 《光谱学快报》2013,46(6):399-411
Laser-induced breakdown spectroscopy (LIBS) technique was applied for rapid analysis of major and minor elements composing geological samples including minerals, rocks, and a soil sample. The plasma was produced in air at atmospheric pressure by focusing on the targets a pulsed infrared Nd:YAG laser in open-path configuration. The emitted light in the UV-Vis was analyzed by a compact LIBS system to measure spectral emission lines of Si, Al, Fe, Ca, Na, K, Mg, C, Cu, Mn, and Ti. The experimental issues relevant for the analysis of the different samples were investigated by taking into account their peculiar features: drilling through a weathered layer, roughness and grain-size considerations, statistical averaging, and accuracy of the measurements. In this approach, the characterization of the samples was achieved by studying the relative variations of the emission intensities of each element normalized with respect to an internal standard. The present study shows the usefulness of LIBS as a tool for reliable identification of field samples. 相似文献
999.
Gabriele Grillo Hynek Kovařík Yehuda Pinchover 《Archive for Rational Mechanics and Analysis》2014,213(1):215-243
We prove on-diagonal bounds for the heat kernel of the Dirichlet Laplacian ${-\Delta^D_\Omega}$ in locally twisted three-dimensional tubes Ω. In particular, we show that for any fixed x the heat kernel decays for large times as ${{\rm e}^{-E_1t} t^{-3/2}}$ , where E 1 is the fundamental eigenvalue of the Dirichlet Laplacian on the cross section of the tube. This shows that any, suitably regular, local twisting speeds up the decay of the heat kernel with respect to the case of straight (untwisted) tubes. Moreover, the above large time decay is valid for a wide class of subcritical operators defined on a straight tube. We also discuss some applications of this result, such as Sobolev inequalities and spectral estimates for Schrödinger operators ${-\Delta^D_\Omega-V}$ . 相似文献
1000.
Windischberger C Langenberger H Sycha T Tschernko EM Fuchsjäger-Mayerl G Schmetterer L Moser E 《Magnetic resonance imaging》2002,20(8):575-582
BOLD-based functional MRI (fMRI) can be used to explicitly measure hemodynamic aspects and functions of human neuro-physiology. As fMRI measures changes in regional cerebral blood flow and volume as well as blood oxygenation, rather than neuronal brain activity directly, other processes that may change the above parameters have to be examined closely to assess sensitivity and specificity of fMRI results. Physiological processes that can cause artifacts include cardiac action, breathing and vasomotion. Although there has been substantial research on physiological artifacts and appropriate compensation methods, controversy still remains on the mechanisms that cause the fMRI signal fluctuations. Respiratory-correlated fluctuations may either be induced by changes of the magnetic field homogeneity due to moving organs, intra-thoracic pressure differences, respiration-dependent vasodilation or oxygenation differences. The aim of this study was to characterize the impact of different breathing patterns by varying respiration frequency and/or tidal volume on EPI time courses of the resting human brain. The amount of respiration-related oscillations during three respiration patterns was quantified, and statistically significant differences were obtained in white matter only: p < 0.03 between 6 vs. 12 ml/kg body weight end tidal volume at a respiration frequency of 15/min, p < 0.03 between 12 vs. 6 ml/kg body weight and 15 vs. 10 respiration cycles/min. There was no significant difference between 15 vs. 10 respiration cycles/min at an end tidal volume of 6 ml/kg body weight (p = 0.917). In addition, the respiration-affected brain regions were very similar with EPI readout in the a-p and l-r direction. Based on our results and published literature we hypothesize that venous oxygenation oscillations due to changing intra-thoracic pressure represent a major factor for respiration-related signal fluctuations and increase significantly with increasing end tidal volume in white matter only. 相似文献