A versatile analytical method(VAM) for calculating the harmonic components of the magnetomotive force(MMF) generated by diverse armature windings in AC machines has been proposed, and the versatility of this method ha...A versatile analytical method(VAM) for calculating the harmonic components of the magnetomotive force(MMF) generated by diverse armature windings in AC machines has been proposed, and the versatility of this method has been established in early literature. However, its practical applications and significance in advancing the analysis of AC machines need further elaboration. This paper aims to complement VAM by augmenting its theory, offering additional insights into its conclusions, as well as demonstrating its utility in assessing armature windings and its application of calculating torque for permanent magnet synchronous machines(PMSM). This work contributes to advancing the analysis of AC machines and underscores the potential for improved design and performance optimization.展开更多
A cylindrical gates model of the static induction transistor is proposed and mirror method is used to calculate the distribution of electric potential.The results show that:the potential barrier is directly determined...A cylindrical gates model of the static induction transistor is proposed and mirror method is used to calculate the distribution of electric potential.The results show that:the potential barrier is directly determined by channel over pinched-off factor;gate efficiency η decreases as the gate dimension α 2 and shifted gate voltage are minished,and what differs from the first-order theory is that η will tend to zero at the shifted gate voltage tends to zero when V D=0;at low current,the voltage amplification factor μ increases as the drain current rising.When the drain current reaches certain degree,the voltage amplification factor keeps almost constant.In the end,an analytical description of SIT’s characteristic suited to both triode-like and mixed I-V characteristics are obtained.The predicted I-V curves are consistent perfectly with the reported experimental ones.展开更多
The Modified Recursive Fourier Meth(MRFM) is presented here and applied to DISA series integrated substation automation systems for AC measurement comparing with the other measure methods used in RTUs. The application...The Modified Recursive Fourier Meth(MRFM) is presented here and applied to DISA series integrated substation automation systems for AC measurement comparing with the other measure methods used in RTUs. The application shows its high accuracy, good real time response. And it can measure harmonic in real bine.展开更多
V-doped TiO2/AC supported catalysts were formed on the surface of active carbon（AC） by sol-gel method from ammonium metavanadate and tetrabutylorthotitanate,and characterized by X-ray diffraction（XRD） and UV-vis s...V-doped TiO2/AC supported catalysts were formed on the surface of active carbon（AC） by sol-gel method from ammonium metavanadate and tetrabutylorthotitanate,and characterized by X-ray diffraction（XRD） and UV-vis spectrophotometry.The photocatalytic activities of the supported catalysts were evaluated in photo-degradation of methyl orange and omethoate aqueous solutions,respectively.The results showed that both the rutile phase and anatase phase are formed.The supported catalyst showed the highest photocatalytic activity at the mass fraction of V in TiO2 of 1.5%.The band edges in UV-vis spectra of the V-doped TiO2/AC supported catalyst showed a red-shift compared with un-doped membrane;but there was no certain correlation between these red-shifts of band-edges and the photocatalytic efficiency of the supported catalyst.In photocatalytic degradation,electrons may be transferred directly from the reactant to the conductive band of V2O5 and so the mechanism of the degradation was changed.Electrons that transferred to the conductive band of V2O5 may be excited by irradiation to the conductive band of TiO2 and be captured by O2.However,they may also be transferred to the valence band of TiO2 and recombine with photogenerated holes.So a moderate amount of V in the supported catalyst may lead an increased the photocatalytic activity.展开更多
基金supported by the Natural Science Foundation of China under Grant U22A20214 and Grant 51837010。
文摘A versatile analytical method(VAM) for calculating the harmonic components of the magnetomotive force(MMF) generated by diverse armature windings in AC machines has been proposed, and the versatility of this method has been established in early literature. However, its practical applications and significance in advancing the analysis of AC machines need further elaboration. This paper aims to complement VAM by augmenting its theory, offering additional insights into its conclusions, as well as demonstrating its utility in assessing armature windings and its application of calculating torque for permanent magnet synchronous machines(PMSM). This work contributes to advancing the analysis of AC machines and underscores the potential for improved design and performance optimization.
文摘A cylindrical gates model of the static induction transistor is proposed and mirror method is used to calculate the distribution of electric potential.The results show that:the potential barrier is directly determined by channel over pinched-off factor;gate efficiency η decreases as the gate dimension α 2 and shifted gate voltage are minished,and what differs from the first-order theory is that η will tend to zero at the shifted gate voltage tends to zero when V D=0;at low current,the voltage amplification factor μ increases as the drain current rising.When the drain current reaches certain degree,the voltage amplification factor keeps almost constant.In the end,an analytical description of SIT’s characteristic suited to both triode-like and mixed I-V characteristics are obtained.The predicted I-V curves are consistent perfectly with the reported experimental ones.
文摘The Modified Recursive Fourier Meth(MRFM) is presented here and applied to DISA series integrated substation automation systems for AC measurement comparing with the other measure methods used in RTUs. The application shows its high accuracy, good real time response. And it can measure harmonic in real bine.
文摘V-doped TiO2/AC supported catalysts were formed on the surface of active carbon（AC） by sol-gel method from ammonium metavanadate and tetrabutylorthotitanate,and characterized by X-ray diffraction（XRD） and UV-vis spectrophotometry.The photocatalytic activities of the supported catalysts were evaluated in photo-degradation of methyl orange and omethoate aqueous solutions,respectively.The results showed that both the rutile phase and anatase phase are formed.The supported catalyst showed the highest photocatalytic activity at the mass fraction of V in TiO2 of 1.5%.The band edges in UV-vis spectra of the V-doped TiO2/AC supported catalyst showed a red-shift compared with un-doped membrane;but there was no certain correlation between these red-shifts of band-edges and the photocatalytic efficiency of the supported catalyst.In photocatalytic degradation,electrons may be transferred directly from the reactant to the conductive band of V2O5 and so the mechanism of the degradation was changed.Electrons that transferred to the conductive band of V2O5 may be excited by irradiation to the conductive band of TiO2 and be captured by O2.However,they may also be transferred to the valence band of TiO2 and recombine with photogenerated holes.So a moderate amount of V in the supported catalyst may lead an increased the photocatalytic activity.
