781 research outputs found

    Topological Excitation in Skyrme Theory

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    Based on the Ï•\phi-mapping topological current theory and the decomposition of gauge potential theory, we investigate knotted vortex lines and monopoles in Skyrme theory and simply discuss the branch processes (splitting, merging and intersection) during the evolution of the monopoles.Comment: 10 pages, 0 figure

    Detecting Extra Dimension by Helium-like Ions

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    Considering that gravitational force might deviate from Newton's inverse-square law and become much stronger in small scale, we present a method to detect the possible existence of extra dimensions in the ADD model. By making use of an effective variational wave function, we obtain the nonrelativistic ground energy of a helium atom and its isoelectronic sequence. Based on these results, we calculate gravity correction of the ADD model. Our calculation may provide a rough estimation about the magnitude of the corresponding frequencies which could be measured in later experiments.Comment: 8 pages, no figures, accepted by Mod. Phys. Lett.

    Accumulation Pattern of Flavonoids in Cabernet Sauvignon Grapes Grown in a Low-Latitude and High-Altitude Region

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    Particular climate conditions in a low-latitude and high-altitude region endow grape berries with distinctivequality characteristics. So far, few reports have been concerned with the formation of berry flavour in such aregion. This study aimed to investigate the accumulation pattern of flavonoids in Vitis vinifera L. cv. CabernetSauvignon grape berries growing at different altitudes of the highland in southwest China in two consecutivevintages. In addition to the 3-O-monoglucosides and 3-O-acyl monoglucosides of the five main anthocyanidins(delphinidin, cyanidin, peonidin, petunidin and malvidin), some uncommon anthocyanins, such as threediglucosides of anthocyanidins and pelargonidin-3-O-glucoside, were detected in the grape berries. Higheraltitude cultivation greatly promoted the production of anthocyanins and flavonols, particularly cyanidintypeanthocyanins and quercetin-type flavonols from the F3’H branch of the flavonoid biosynthetic pathway.Flavan-3-ols from both branches were comparatively less influenced by vineyard altitude. Vintage in thishigh-altitude region also had a dramatic influence on the accumulation of flavonoids. Most of the anthocyaninand flavonol components were affected more by vineyard altitude than by vintage, whereas the accumulationof flavan-3-ols differed mainly between vintages. The present data will not only improve the understandingof flavonoid accumulation in grapes from a high-altitude region with different climates, but also providepractical guidance for the production of high-quality grapes and wine

    Localization of fermionic fields on braneworlds with bulk tachyon matter

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    Recently, Pal and Skar in [arXiv:hep-th/0701266] proposed a mechanism to arise the warped braneworld models from bulk tachyon matter, which are endowed with a thin brane and a thick brane. In this framework, we investigate localization of fermionic fields on these branes. As in the 1/2 spin case, the field can be localized on both the thin and thick branes with inclusion of scalar background. In the 3/2 spin extension, the general supergravity action coupled to chiral supermultiplets is considered to produce the localization on both the branes as a result.Comment: 9 pages, no figure

    Bis[1-(4-cyano­benz­yl)pyrazinium] bis­(1,2-dicyano­ethene-1,2-dithiol­ato)nickelate(II)

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    The asymmetric unit of the title complex, (C12H10N3)2[Ni(C4N2S2)2], consists of one 1-(4-cyano­benz­yl)pyrazinium cation and one half of an [Ni(mnt)2]2− dianion (mnt2− is 1,2-dicyano­ethene-1,2-dithiol­ate). The Ni2+ ion is located on an inversion center and is coordinated by four S atoms from two mnt2− ligands, exhibiting a square-planar coordination geometry. The cation adopts a conformation where both the pyrazine ring and the benzene ring are twisted with respect to the C—C—N reference plane by 16.5 (2) and 69.8 (1)°, respectively
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