Recent years,the polarization response of ferroelectrics has been entirely studied.However,it is found that the polarization may disappear gradually with the continually applied of electric field.In this paper,taking ...Recent years,the polarization response of ferroelectrics has been entirely studied.However,it is found that the polarization may disappear gradually with the continually applied of electric field.In this paper,taking K0.48Na0.52NbO3(KNN)as an example,it was demonstrated that the residual polarization began to decrease when the electric field frequency increased to a certain extent using a phase-field methods.The results showed that the content of out-of-plane domains increased first and then decreased with the increase of applied electric field frequency,the maximum polarization disappeared at high frequencies,and the hysteresis loop became elliptical.In order to further study the abnormal changes of hysteresis loops of ferroelectrics under high electric field frequency,we analyzed the hysteresis loop and dielectric response of solid solution 0.1SrTiO_(3)-0.9K_(0.48)Na_(0.52)NbO_(3).It was found that the doped hysteresis loop maintained its shape at higher frequency and the dielectric constant increased.This kind of doping has a higher field frequency adaptability,which has a key guiding role in improving the dielectric properties of ferroelectric thin films and expanding the frequency application range of ferroelectric nano memory。展开更多
The strength of the power frequency electric intensity and magnetic field of the 500-kV double circuit transmission lines was calculated by using the equivalent charge method and the Ampere's Law, and the environm...The strength of the power frequency electric intensity and magnetic field of the 500-kV double circuit transmission lines was calculated by using the equivalent charge method and the Ampere's Law, and the environmental impact factors of the fields were evaluated. By optimizing the phase sequence, the frequency electric intensity and magnetic field strength can be reduced. Within a distance of 25 m from the center of the transmission line, the power frequency electric intensity and magnetic field strength fall off sharply with the distance increase. Finally, the best phase sequence and the minimum ground clearance of the transmission lines were obtained to meet the requirements of the least impact on envionment.展开更多
基金supported by National Defense Basic Scientific Research Program of China(Grant Nos.JCKY2020408B002,WDZC2022-12).
文摘Recent years,the polarization response of ferroelectrics has been entirely studied.However,it is found that the polarization may disappear gradually with the continually applied of electric field.In this paper,taking K0.48Na0.52NbO3(KNN)as an example,it was demonstrated that the residual polarization began to decrease when the electric field frequency increased to a certain extent using a phase-field methods.The results showed that the content of out-of-plane domains increased first and then decreased with the increase of applied electric field frequency,the maximum polarization disappeared at high frequencies,and the hysteresis loop became elliptical.In order to further study the abnormal changes of hysteresis loops of ferroelectrics under high electric field frequency,we analyzed the hysteresis loop and dielectric response of solid solution 0.1SrTiO_(3)-0.9K_(0.48)Na_(0.52)NbO_(3).It was found that the doped hysteresis loop maintained its shape at higher frequency and the dielectric constant increased.This kind of doping has a higher field frequency adaptability,which has a key guiding role in improving the dielectric properties of ferroelectric thin films and expanding the frequency application range of ferroelectric nano memory。
文摘The strength of the power frequency electric intensity and magnetic field of the 500-kV double circuit transmission lines was calculated by using the equivalent charge method and the Ampere's Law, and the environmental impact factors of the fields were evaluated. By optimizing the phase sequence, the frequency electric intensity and magnetic field strength can be reduced. Within a distance of 25 m from the center of the transmission line, the power frequency electric intensity and magnetic field strength fall off sharply with the distance increase. Finally, the best phase sequence and the minimum ground clearance of the transmission lines were obtained to meet the requirements of the least impact on envionment.
