Modelling of Wideband Concentric Ring Frequency Selective Surface for 5G Devices

Frequency selective surfaces(FSSs)play an important role in wireless systems as these can be used as filters,in isolating the unwanted radiation,in microstrip patch antennas for improving the performance of these antennas and in other 5G applications.The analysis and design of the double concentric ring frequency selective surface(DCRFSS)is presented in this research.In the sub-6 GHz 5G FR1 spectrum,a computational synthesis technique for creating DCRFSS based spatial filters is proposed.The analytical tools presented in this study can be used to gain a better understanding of filtering processes and for constructing the spatial filters.Variation of the loop sizes,angles of incidence,and polarization of the concentric rings are the factors which influence the transmission coefficient as per the thorough investigation performed in this paper.A novel synthesis approach based on mathematical equations that may be used to determine the physical parameters ofDCRFSSbased spatial filters is presented.The proposed synthesis technique is validated by comparing results from high frequency structure simulator(HFSS),Ansys electronic desktop circuit editor,and an experimental setup.Furthermore,the findings acquired from a unit cell are expanded to a 2×2 array,which shows identical performance and therefore proves its stability.

Make Leapfrogging Development By Concentrating Resource On Selected Targets

The Chinese Academy of Sci-ences (CAS) has begun introducingthe trial implementation of theKnowledge Innovation Program(KIP)in an all-round manner just as,at the beginning of the new century,the state is about to implement itsTenth Five-Year Plan for thecountry’s ongoing economic andsocial development. This will

Optimization of two-factor(pH and ion concentration)simultaneous selection in HPLC using a statistical method

A computer-assisted method is presented for simultaneous optimization of pH and ion con- centration selection for the optimal separation in reversed-phase HPLC.The method is based on a polynomial estimation from nine preliminary experiments according to two-factor rectangular design. This is followed by a two-dimension computer scanning technique.Resolution is used as the selection criterion.Good agreement was obtained between predicted data and experimental results.

Flotation performance and adsorption mechanism of styrene phosphonic acid as a collector to synthetic(Ce,La)2O3

The flotation performances of styrene phosphonic acid（SPA） to synthetic（Ce,La）2O3（REO）, calcium fluorite（CaF2） and fluorapatite（Ca5F（PO4）3） were investigated by flotation tests, flotation of synthetic mixed mineral, the surface adsorption capacity and the polarizing microscopy to solve the flotation separation problem of rare earth oxides from roasted concentrate. The flotation test results indicated that compared with CaF2 and Ca5F（PO4）3, SPA exhibited superior collecting performance to direct flotation recovery of REO and floated out above 90% REO at pH 3–6. However, the collecting ability of SPA to CaF2 and Ca5F（PO4）3 was extremely weak and the highest recovery was only 20% at pH 2–11. The flotation of synthetic mixed mineral showed that SPA was a good collector reagent for flotation of synthetic REO at pH 5, so REO, CaF2 and Ca5F（PO4）3 could be separated from roasted concentrate by using SPA as a collector. The surface adsorption capacity tests and polarizing microscopy results confirmed that SPA was adsorbed on REO surface, while CaF2 and Ca5F（PO4）3 were not. The adsorption mechanism of SPA to synthetic REO was studied by solution chemistry analysis of collector, the ζ-potential tests, infrared spectroscopy and X-ray photoelectron spectroscopy（XPS） analyses. The results indicated that SPA was physically adsorbed onto REO surface, which exhibited excellent flotation selectivity to REO against CaF2 and Ca5F（PO4）3.

Influence of Mechanical Activation on Acid Leaching Dephosphorization of High-phosphorus Iron Ore Concentrates

High pressure roll grinding（HPRG）and ball milling were compared to investigate the influence of mechanical activation on the acid leaching dephosphorization of a high-phosphorus iron ore concentrate,which was manufactured through magnetizing roasting-magnetic separation of high-phosphorus oolitic iron ores.The results indicated that when high-phosphorus iron ore concentrates containing 54.92 mass% iron and 0.76 mass% phosphorus were directly processed through acid leaching,iron ore concentrates containing 55.74mass%iron and 0.33mass%phosphorus with an iron recovery of 84.64%and dephosphorization of 63.79% were obtained.When high-phosphorus iron ore concentrates activated by ball milling were processed by acid leaching,iron ore concentrates containing56.03mass%iron and 0.21mass% phosphorus with an iron recovery of 85.65% and dephosphorization of 77.49%were obtained.Meanwhile,when high-phosphorus iron ore concentrates activated by HPRG were processed by acid leaching,iron ore concentrates containing 58.02mass%iron and 0.10mass% phosphorus were obtained,with the iron recovery reaching 88.42% and the dephosphorization rate reaching 88.99%.Mechanistic studies demonstrated that ball milling can reduce the particle size,demonstrating aprominent reunion phenomenon.In contrast,HPRG pretreatment contributes to the formation of more cracks within the particles and selective dissociation of iron and P bearing minerals,which can provide the favorable kinetic conditions to accelerate the solid-liquid reaction rate.As such,the crystal structure is destroyed and the surface energy of mineral particles is strengthened by mechanical activation,further strengthening the dephosphorization.