17,470 research outputs found

    Detection of Striped Superconductors Using Magnetic Field Modulated Josephson Effect

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    In a very interesting recent Letter\cite{berg}, the authors suggested that a novel form of superconducting state is realized in La2−x_{2-x}Bax_xCuO4_4 with xx close to 1/8. This suggestion was based on experiments\cite{li} on this compound which found predominantly two-dimensional (2D) characters of the superconducting state, with extremely weak interplane coupling. Later this specific form of superconducting state was termed striped superconductors\cite{berg08}. The purpose of this note is to point out that the suggested form\cite{berg} of the superconducting order parameter can be detected directly using magnetic field modulated Josephson effect.Comment: Expanded version as appeared in prin

    Perspectives and utilization technologies of chicory (Cichorium intybus L.): A review

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    Exploring and developing multiple utility technologies of plant resources is an alternative way for improving the efficiency of land used for food and fuel production. Chicory (Cichorium intybus L.) has a nutritional quality comparable to lucerne as it contains similar proportions of protein, lipid, minerals and other nutrients. Based on its chemical and biological activities, this research work evaluated and overviewed recent advances in utilization technologies and studies of chicory. It focuses on the biochemical compositions and physiological bioactivities of extractives from chicory and clearly states the promising potential utility technologies of the plant: Curative effect as a forage or vegetable with good digestibility, use of chicory in confectionery products and beverages, potential use in discovering new effective medicine and the development of new salubrious functional foods, additives and other profitable green bioproducts. However, a significant research gap still remains in these pharmacological actions and discoveries, and as such, the utilization of the health benefits of this plant should be put into practice. Thus, future research needs to be done in order to gain a better understanding and to further elucidate mechanisms of chicory and its extractives that are rationally suggested.Key words: Chicory, biochemical composition, pharmacological activities, utilization technologies

    Mixed adsorption and surface tension prediction of nonideal ternary surfactant systems

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    To deal with the mixed adsorption of nonideal ternary surfactant systems, the regular solution approximation for nonideal binary surfactant systems is extended and a pseudo-binary system treatment is also proposed. With both treatments, the compositions of the mixed monolayer and the solution concentrations required to produce given surface tensions can be predicted based only on the gamma-LogC curves of individual surfactants and the pair interaction parameters. Conversely, the surface tensions of solutions with different bulk compositions can be predicted by the surface tension equations for mixed surfactant systems. Two ternary systems: SDS/Hyamine 1622/AEO7, composed of homogeneous surfactants, and AES/DPCl/AEO9, composed of commercial surfactants, in the presence of excess NaCl, are examined for the applicability of the two treatments. The results show that, in general, the pseudo-binary system treatment gives better prediction than the extended regular solution approximation, and the applicability of the latter to typical anionic/cationic/nonionic nonideal ternary surfactant systems seems to depend on the combined interaction parameter, (βans+βcns)/2−βacs/4 {\mathop {(\beta }\nolimits_{an}^s } + {\mathop \beta \nolimits_{cn}^s })/2 - {\mathop \beta \nolimits_{ac}^s }/4 : the more it deviates from zero, the larger the prediction difference. If (βans+βcns)/2−βacs/4 {\mathop {(\beta }\nolimits_{an}^s } + {\mathop \beta \nolimits_{cn}^s })/2 - {\mathop \beta \nolimits_{ac}^s }/4 rarr0, good agreements between predicted and experimental results can be obtained and both treatments, though differently derived, are interrelated and tend to be equivalent

    Low-Frequency Raman Modes and Electronic Excitations In Atomically Thin MoS2 Crystals

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    Atomically thin MoS2_{2} crystals have been recognized as a quasi-2D semiconductor with remarkable physics properties. This letter reports our Raman scattering measurements on multilayer and monolayer MoS2_{2}, especially in the low-frequency range (<<50 cm−1^{-1}). We find two low-frequency Raman modes with contrasting thickness dependence. With increasing the number of MoS2_{2} layers, one shows a significant increase in frequency while the other decreases following a 1/N (N denotes layer-number) trend. With the aid of first-principle calculations we assign the former as the shear mode E2g2E_{2g}^{2} and the latter as the compression vibrational mode. The opposite evolution of the two modes with thickness demonstrates novel vibrational modes in atomically thin crystal as well as a new and more precise way to characterize thickness of atomically thin MoS2_{2} films. In addition, we observe a broad feature around 38 cm−1^{-1} (~5 meV) which is visible only under near-resonance excitation and pinned at the fixed energy independent of thickness. We interpret the feature as an electronic Raman scattering associated with the spin-orbit coupling induced splitting in conduction band at K points in their Brillouin zone.Comment: 5 pages, 4 figure
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