A feasible method for synthesizing millimeter-wave conical array and optimizing low cross-polarization is proposed.Starting from the far-field superposition principle,an efficient approach including element mutual cou...A feasible method for synthesizing millimeter-wave conical array and optimizing low cross-polarization is proposed.Starting from the far-field superposition principle,an efficient approach including element mutual coupling and mounted platform effects is used to calculate the far-field patterns.A coordinate transform is applied to create polarization quantities,and a general process for the element polarized pattern transformation is performed.Corresponding numerical example is given and the desired sidelobe level and low cross-polarization are optimized.The numerical results indicate the proposed method is valid.展开更多
Kinetics of adsorption of furfural from aqueous solution on zeolite： ZSM-5 （Zeolite Socony Mobil-5）, surface have been studied at room temperature. For evaluation of adsorption properties and mechanism, the adsorpt...Kinetics of adsorption of furfural from aqueous solution on zeolite： ZSM-5 （Zeolite Socony Mobil-5）, surface have been studied at room temperature. For evaluation of adsorption properties and mechanism, the adsorption isotherms have been described. Adsorption data have been fitted by the models Langmuir, Freundlich, BET （Brunauer-Emmett-Teller）, Redlich-Peterson, T6th and Dubinin-Radushkevitch. Adsorption capacity of zeolite for furfural in the studied range of concentrations （0-100 mmol/L） is found to reach 60 mg/g. The Langmuir and BET models are found to be the best for experimental data description with Re= 0.9959 and 0.9994, respectively. The Dubinin-Radushkevitch model has been used for determination of the equation constants. The latter has been applied further for calculation of energy of adsorption of furfural on zeolite ZSM-5, which is equal to 11 kJ/mol, indicating the chemical nature of adsorption interaction. The kinetics data have been modeled using pseudo-first-order and pseudo-second-order models. The kinetic sorption offered rather good fit with pseudo-second-order model with the Re value of 0.9821. The rate-limiting step is found to be intraparticle diffusion. Zeolite ZSM-5 is convenient sorbent for furfural uptake within the tested concentration range.展开更多
The synthesis of nanopowders of terbia compounds with scandia, yttria, and lutetia was carried out using a self-propagating high-temperature synthesis method involving a mixture of nitrates of metals and glycine as a ...The synthesis of nanopowders of terbia compounds with scandia, yttria, and lutetia was carried out using a self-propagating high-temperature synthesis method involving a mixture of nitrates of metals and glycine as a precursor. The nanopowder phase transformations were investigated using X-ray diffraction analysis. It was found that lutetia has a negligible effect on the phase formation in terbia. On the other hand, yttrium and scandium ions significantly suppressed crystallization. The densification kinetics of nanopowders of the Tb_2O_3 compounds and the microstructure of ceramics after microwave sintering were studied using dilatometry and scanning electron microscopy. The introduction of scandia, yttria, or lutetia contributed to the intensification of the densification of the terbia ceramics when heated in a microwave field. Near full-density materials of terbia solid solutions with lutetia and yttria were obtained at about 1600–1640 ℃. The ceramics of scandia–terbia compounds contained the second phase, which causes light scattering.展开更多
基金supported by the Emphases Foundation of Southwest China Institute of Electronic Technology under Grant No. H090024
文摘A feasible method for synthesizing millimeter-wave conical array and optimizing low cross-polarization is proposed.Starting from the far-field superposition principle,an efficient approach including element mutual coupling and mounted platform effects is used to calculate the far-field patterns.A coordinate transform is applied to create polarization quantities,and a general process for the element polarized pattern transformation is performed.Corresponding numerical example is given and the desired sidelobe level and low cross-polarization are optimized.The numerical results indicate the proposed method is valid.
文摘Kinetics of adsorption of furfural from aqueous solution on zeolite： ZSM-5 （Zeolite Socony Mobil-5）, surface have been studied at room temperature. For evaluation of adsorption properties and mechanism, the adsorption isotherms have been described. Adsorption data have been fitted by the models Langmuir, Freundlich, BET （Brunauer-Emmett-Teller）, Redlich-Peterson, T6th and Dubinin-Radushkevitch. Adsorption capacity of zeolite for furfural in the studied range of concentrations （0-100 mmol/L） is found to reach 60 mg/g. The Langmuir and BET models are found to be the best for experimental data description with Re= 0.9959 and 0.9994, respectively. The Dubinin-Radushkevitch model has been used for determination of the equation constants. The latter has been applied further for calculation of energy of adsorption of furfural on zeolite ZSM-5, which is equal to 11 kJ/mol, indicating the chemical nature of adsorption interaction. The kinetics data have been modeled using pseudo-first-order and pseudo-second-order models. The kinetic sorption offered rather good fit with pseudo-second-order model with the Re value of 0.9821. The rate-limiting step is found to be intraparticle diffusion. Zeolite ZSM-5 is convenient sorbent for furfural uptake within the tested concentration range.
基金supported by the Russian Foundation for Basic Research (Grant No.16-03-00595)
文摘The synthesis of nanopowders of terbia compounds with scandia, yttria, and lutetia was carried out using a self-propagating high-temperature synthesis method involving a mixture of nitrates of metals and glycine as a precursor. The nanopowder phase transformations were investigated using X-ray diffraction analysis. It was found that lutetia has a negligible effect on the phase formation in terbia. On the other hand, yttrium and scandium ions significantly suppressed crystallization. The densification kinetics of nanopowders of the Tb_2O_3 compounds and the microstructure of ceramics after microwave sintering were studied using dilatometry and scanning electron microscopy. The introduction of scandia, yttria, or lutetia contributed to the intensification of the densification of the terbia ceramics when heated in a microwave field. Near full-density materials of terbia solid solutions with lutetia and yttria were obtained at about 1600–1640 ℃. The ceramics of scandia–terbia compounds contained the second phase, which causes light scattering.
