Magnetic properties of composites of Tb028Dy072Fe2 and polyvinylidene fluoride

Bi-ferroic particulate composites with Tb0.28Dy0.72Fe2 (Terfenol-D) particles randomly dispersed in ferroelectric polyvinylidene fluoride matrix prepared by a simple hot-pressing procedure were investigated. With increasing concentration of Terfenol-D, the magnetic susceptibility, saturation magnetization and initial permeability of the composites increases. The dependence of the effective magnetostriction on applied bias for the composites is similar to that for bulk Terfenol-D, but the effective magnetostriction strongly depends on the volume fraction of Terfenol-D. The observed behaviour of the composite is reasonably described by using effective medium theories

Determination of the number of ψ(3686) events taken at BESIII

The number of ψ(3686) events collected by the BESIII detector during the 2021 run period is determined to be (2259.3±11.1)×106 by counting inclusive ψ(3686) hadronic events. The uncertainty is systematic and the statistical uncertainty is negligible. Meanwhile, the numbers of ψ(3686) events collected during the 2009 and 2012 run periods are updated to be (107.7±0.6)×106 and (345.4±2.6)×106, respectively. Both numbers are consistent with the previous measurements within one standard deviation. The total number of ψ(3686) events in the three data samples is (2712.4±14.3)×10^