The effect of rare-earth oxide CeO2 on the electromagnetic properties of ferrite-ceramic composite materials
In this work, we present the influence of rare-earth element additions on this new composite material. A great improvement of the electromagnetic properties was obtained. The constituent chemicals were mixed in the stoichiometric composition, calcined at 850degC for 2 h and blended with PVA to press into steroidal or disc shaped specimens. These specimens were sintered at 900degC for 2.5 h in air. The complex permeability, capacity and impedance were measured with HP4291B and 4291A instruments, respectively, in the frequency range from 1MHz to 2GHz.
Electromagnetic properties of a new ferrite-ceramic low-temperature cocalcined (LTCC) composite materials
A new ferrite-ceramic composite material with inductive, capacitive, and impedance properties was fabricated by a solid-state reaction. The composite materials were prepared with ferromagnetic NiCuZn ferrites and ferroelectric BaTiO/sub 3/ perovskite. Co/sup 2+/, Bi/sup 3+/, Y/sup 3+/, Dy/sup 3+/, and Ca/sup 2+/ ions are selected to improve the electromagnetic properties. We found that this new material has excellent frequency dependence of magnetic and dielectric properties, which can be used not only as inductor and resistor materials but also as capacitor materials in the wide range of 1 KHz to 4 GHz. At 1 MHz, the dielectric constant /spl epsiv/' of the composite material is 60-120, and the initial permeability /spl mu/' is 5.6-13.
The parallel waveform relaxation stochastic Runge–Kutta method for stochastic differential equations
For large-scale non-autonomous Stratonovich stochastic differential equations, we study a very general parallel waveform relaxation process which is on the basis of stochastic Runge–Kutta (SRK) method of mean-square order 1.0 in this literature. The convergence of the whole parallel numerical iterative scheme can be guaranteed and the scheme provides better properties in terms of decreasing the load of the computation and operating speed. At the same time, the related limit method is also introduced as the continuous approximation derived from the iterative scheme. In the approximation interval, it is worth noting that the mean-square order of the parallel numerical iterative scheme can be kept consistent with the previous SRK method at any arbitrary time point, not just at discrete points. Some numerical simulations are presented to elaborate the computing efficiency of the parallel numerical iterative scheme.