An improved generalized admittance (GAM) matrix technique is presented in this paper. Matrix transformation eliminates the
singularity factor of GAM, denominator (1+Γ), because of new presentations of GAM. The relationship equations between II-port
current and I-port incidence wave is computed by mode matching method. The generalized scattering matrix (GSM) of waveguide
structure and its discontinuity problems is obtained with relationship equations and reflection coefficients. The GSM’s of
millimeter-wave multistepped bend and T-junction in rectangular waveguide are computed by the improved GAM technique. The
results comparisons between the proposed method and commercial software HFSS10.0 show the validity of the proposed method,
which improves the validity of the GAM technique and reduces mathematical efforts. It is general, very efficient and can be
used to solve other complicated and multiport network problems. 相似文献
A simplified Olami-Feder-Christensen model on a random network has been studied. We propose a new toppling rule — when there is an unstable site toppling, the energy of the site is redistributed to its nearest neighbors randomly not averagely. The simulation results indicate that the model displays self-organized criticality when the system is conservative, and the avalanche size probability distribution of the system
obeys finite size scaling. When the system is nonconservative, the model
does not display scaling behavior. Simulation results of our model with
different nearest neighbors q is also compared, which indicates that the
spatial topology does not alter the critical behavior of the system. 相似文献
We analyze a dielectric waveguide with a photonic crystal core. Using constant frequency contour analysis, we show that the modal behavior of this structure is drastically different from that of a conventional slab waveguide. In particular, at a given frequency the lowest-order guided mode can have an odd symmetry or can have more than one nodal plane in its field distribution. Also, there exist several single-mode regions with a different modal profile in each region. Finally, a single-mode waveguide for the fundamental mode with a large core and strong confinement can be realized. All these behaviors are confirmed by our three-dimensional finite-difference time-domain simulations. 相似文献
Metal nanoparticles have been combined with magnet metal–organic frameworks (MOFs) to afford new materials that demonstrate an efficient catalytic degradation, high stability, and excellent reusability in areas of catalysis because of their exceptionally high surface areas and structural diversity. Magnetic MxOy@N-C (M = Fe, Co, Mn) nanocrystals were formed on nitrogen-doped carbon surface by using 8-hydroxyquinoline as a C/N precursor. The Co@N-C, MnO@N-C, and Fe/Fe2O3@N-C catalysts were characterized by X-ray diffraction (XRD), Raman, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), N2 adsorption/desorption, and X-ray photoelectron spectroscopy (XPS). The catalytic performances of catalysts were thoroughly investigated in the oxidation of aniline solution based on sulfate radicals (SO4?.) toward Fenton-like reaction. Magnetic MxOy@N-C exhibits an unexpectedly high catalytic activity in the degradation of aniline in water. A high magnetic MxOy@N-C catalytic activity was observed after the evaluation by aniline degradation in water. Aniline degradation was found to follow the first-order kinetics, and as a result, various metals significantly affected the structures and performances of the catalysts, and their catalytic activity followed the order of Co > Mn > Fe. The nanoparticles displayed good magnetic separation under the magnetic field.
