3,177 research outputs found
Rigid vortices in MgB2
Magnetic relaxation of high-pressure synthesized MgB bulks with different
thickness is investigated. It is found that the superconducting dia-magnetic
moment depends on time in a logarithmic way; the flux-creep activation energy
decreases linearly with the current density (as expected by Kim-Anderson
model); and the activation energy increases linearly with the thickness of
sample when it is thinner than about 1 mm. These features suggest that the
vortices in the MgB are rather rigid, and the pinning and creep can be well
described by Kim-Anderson model.Comment: Typo corrected & reference adde
Triaqua-1κO,2κ2 O-bis(2,2′-bipyridine)-1κ2 N,N′;2κ2 N,N′-chlorido-1κCl-μ-terephthalato-1:2κ2 O 1:O 4-dicopper(II) nitrate monohydrate
In the binuclear title compound, [Cu2(C8H4O4)Cl(C10H8N2)2(H2O)3]NO3·H2O, the two crystallographically independent CuII ions have similar coordination environments. One of the CuII ions has a square-pyramidal arrangement, which is defined by a water molecule occupying the apical position, with the equatorial ligators consisting of two N atoms from a 2,2′-bipyridine molecule, one carboxylate O atom from a terephthalate ligand and one O atom from a water molecule. The other CuII ion has a similar coordination environment, except that the apical position is occupied by a chloride ligand instead of a water molecule. An O—H⋯O and O—H⋯Cl hydrogen-bonded three-dimensional network is formed between the components
The positive response in grape secondary metabolites under controlled stresses: a review
Grapevine is cultivated worldwide with great economic importance. In recent years, our knowledge of the physiological and molecular basis of berry quality regulation has substantially increased. Abiotic and biotic stresses, such as deficit irrigation, low temperature, light/UV and microbes, to a certain extent, could improve grape berry quality by enhancing flavor metabolites, colorization or aroma compounds. This review summarizes recent data related to the stress of grape berry development, with special emphasis on secondary metabolism and its response to stresses. A full understanding of how grape berry metabolism responds to different stresses is important to improve the biochemical qualities of grapes and resultant products, such as wine in practice
- …