Herein a novel Dyadic Green's Function (DGF) is presented to calculate the field in ElectroMagnetic Compatibility (EMC) chamber. Due to the difficulty of simulating the whole chamber environment, the analysis combines the DGF formulation and the FEM method, with the latter deals with the reflection from absorbers. With DGF formulation for infinite periodic array structures, this paper investigates electromagnetic field in chamber with truncated arrays. The reflection from the absorber serves as the virtual source contributing to the total field. Hence the whole chamber field calculation can be separated from the work of absorber model set-up. Practically the field homogeneity test and Normal Site Attenuation (NSA) test are carried out to evaluate the chamber performance. Based on the method in this paper, the simulation results agree well with the test, and predict successfully the victim frequency points of the chamber. 相似文献
X-ray photoelectron spectroscopy (XPS) was adopted for the analytical characterization of composite titanium dioxide–poly(vinylidenefluoride) (TiO2–PVDF) films developed for applications in the photocatalytic degradation of pollutants.
The composites were deposited on glass substrates by casting or spin coating from TiO2–PVDF suspensions in dimethylformamide (DMF). XPS data on the TiO2–PVDF surface composition were used to optimize preparation conditions (composition of the TiO2/PVDF suspension, deposition technique) in terms of titanium dioxide surface amount and film stability.
The use of spin-coating deposition and the increase of TiO2 amount in the DMF suspensions were found to improve the titanium surface content, although high TiO2/PVDF ratios led to film instability. PVDF–TiO2 films were also used in preliminary photocatalytic degradation tests on isoproturon, a phenylurea herbicide, under solar UV irradiation; the results were compared to direct photolysis to evaluate the catalytic efficiency of immobilized TiO2 and the role played by the PVDF film during the degradation process. 相似文献
Golub et al. (2001, BIT, 41, 7185) gave a generalizedsuccessive over-relaxation method for the augmented systems.In this paper, the connection between the SOR-like method andthe preconditioned conjugate gradient (PCG) method for the augmentedsystems is investigated. It is shown that the PCG method isat least as accurate (fast) as the SOR-like method. Numericalexamples demonstrate that the PCG method is much faster thanthe SOR-like method. 相似文献
Many food algae and red tide algae were cultivated in the f/2 medium, and the nitric oxide (NO) concentration of the medium
and the cell density were determined. The experiments on algae were conducted when different concentrations of NO were added
into the medium using two methods. The results show that low concentrations of NO were self-produced by marine algae during
the exponential growth period and were about nmol/L level. But at the end of the period, i.e., 2 or 3 days before the cell
density reaches the maximum, an NO peak appeared, with the NO concentration reaching 10 nmol/L. The NO threshold concentration
exists according to the influence of exogenous NO on the marine phytoplankton growth. One type is the threshold concentration
that can promote algae growth, and its value is between 10 and 1 nmol level, or even lower. The other type can inhibit the
phytoplankton growth, which is about μmol level or higher. The results indicate that red tide algae are far more sensitive
to NO than are food algae. The fundamental experimental outcome above may provide a new clue for red tide chemical forecast
by inspecting the NO change. 相似文献