From the point of view of application in the microwave band,the theoretic and experimental researches of nanostructural magnetic films were carried out. Micromagnetic structure of the nano-magnetic film was simulated ...From the point of view of application in the microwave band,the theoretic and experimental researches of nanostructural magnetic films were carried out. Micromagnetic structure of the nano-magnetic film was simulated by the finite element method. The typical micromagnetic was obtained. Corresponding experiments were also done aiming at the Co40Fe40B20-SiO2 nano-granular films. The results show that the characteristics of nano-magnetic film correspond with the micromagnetic ripple theory. The microwave permeability of nano-magnetic films deduces and well fits the Landau-Lifshitz-Gilbert(LLG) equation. The films present large microwave permeability and high resonant frequency(μ′ and μ″ at 2 GHz are about 100 and 40 respectively and the resonant frequency is about 2.8 GHz). The additional peak of μ″ originated from perpendicular anisotropy and micromagnetic ripple structure can be suppressed by the annealing process. Thus,the microwave complex permeability spectra of these nano-magnetic films can be tailored for different applications.展开更多
The larch wood was treated by microwave irradiation under different radiant intensity and treating duration. The microwave-treated wood specimens together with the un-treated for comparison were impregnated by water i...The larch wood was treated by microwave irradiation under different radiant intensity and treating duration. The microwave-treated wood specimens together with the un-treated for comparison were impregnated by water in pressure vessel and then tested for permeability, mechanical properties and microstructure change by SEM to study the modification performance of microwave treatment on larch wood. The results showed that under suitable conditions of microwave treatment the permeability of larch wood was improved without noticeable decreasing of the modulus of rupture （MOR） and the modulus of elasticity （MOE）. The radial parenchyma and some pit membrane were ruptured, and tiny cracks were formed in the cell walls. The formation of tiny cracks in the cell walls serves as man-made channels of gas and liquid and this contribute to improve the permeability of the wood.展开更多
基金Project (60771028) supported by the National Natural Science Foundation of China
文摘From the point of view of application in the microwave band,the theoretic and experimental researches of nanostructural magnetic films were carried out. Micromagnetic structure of the nano-magnetic film was simulated by the finite element method. The typical micromagnetic was obtained. Corresponding experiments were also done aiming at the Co40Fe40B20-SiO2 nano-granular films. The results show that the characteristics of nano-magnetic film correspond with the micromagnetic ripple theory. The microwave permeability of nano-magnetic films deduces and well fits the Landau-Lifshitz-Gilbert(LLG) equation. The films present large microwave permeability and high resonant frequency(μ′ and μ″ at 2 GHz are about 100 and 40 respectively and the resonant frequency is about 2.8 GHz). The additional peak of μ″ originated from perpendicular anisotropy and micromagnetic ripple structure can be suppressed by the annealing process. Thus,the microwave complex permeability spectra of these nano-magnetic films can be tailored for different applications.
基金This paper was supported by Science Fund for Distin-guished Young Scholars, Heilongjiang Province (No. JC04-01)
文摘The larch wood was treated by microwave irradiation under different radiant intensity and treating duration. The microwave-treated wood specimens together with the un-treated for comparison were impregnated by water in pressure vessel and then tested for permeability, mechanical properties and microstructure change by SEM to study the modification performance of microwave treatment on larch wood. The results showed that under suitable conditions of microwave treatment the permeability of larch wood was improved without noticeable decreasing of the modulus of rupture （MOR） and the modulus of elasticity （MOE）. The radial parenchyma and some pit membrane were ruptured, and tiny cracks were formed in the cell walls. The formation of tiny cracks in the cell walls serves as man-made channels of gas and liquid and this contribute to improve the permeability of the wood.
