A density functional theory study of the magnetic couplings in Sr2V3O9 type magnetic oxides suggests that whereas the intrachain coupling is always weakly ferromagnetic, the interchain coupling may be antiferromagnetic or even weakly ferromagnetic depending on the nature of the central tetrahedral atom (As/V) cations, and, to a lesser extent, structural details.

smooth coefficients aα(x), L+ be a formally adjoint differential operation. Let L0, L0 be minimal operators (i.e., for example, D(L0) is the clozure of C∞ 0 (Ω) in the norm of the graph ‖u‖L = ‖u‖L2(Ω)+‖Lu‖L2(Ω)), and L, L+ be maximal expansions of L,L+ in the space L2(Ω) respectively (i.e. L = (L0 ) ∗, L+ = (L0)∗), L̃ = L|D(L̃) where D(L̃) is the clozure of C∞(Ω̄) in the norm of the graph ‖u‖L and...

the late eocene-early oligocene sarnowsar granitic rocks and many dacitic to rhyolitic dykesintruded in metamorphosed and metasomatized shale, sandstone, calcite and dolomite marbles andvolcaniclastic and pyroclastic rocks. as a result several million tons of iron ores formed within carbonaterocks in the sangan area. the sarnowsar granitic rocks are mainly granite to granodiorite, metaluminous,...