A surface electromyography(sEMG)signal acquisition circuit based on high-order filtering is designed.We use a two-stage adjustable amplifier and a high-order Sallen-Key bandpass filter to solve the problems of non-adj...A surface electromyography(sEMG)signal acquisition circuit based on high-order filtering is designed.We use a two-stage adjustable amplifier and a high-order Sallen-Key bandpass filter to solve the problems of non-adjustable amplification gain and low filtering order in traditional acquisition circuits.The experimental results show that the designed sEMG signal acquisition device can eliminate power frequency interference effectively,the stopband drop of the filtering part reaches approximately-100 dB/dec,which can effectively extract useful signals between 20-500 Hz,and the amplification gain reaches 60 dB.展开更多
A novel poly（ether sulfone） with oligoaniline pendants（PESOP） was prepared by KaCO3-mediated nucleophilic polycondensation and characterized with Fourier-transform infrared spectrometry（FTIR）, 1H nuclear magneti...A novel poly（ether sulfone） with oligoaniline pendants（PESOP） was prepared by KaCO3-mediated nucleophilic polycondensation and characterized with Fourier-transform infrared spectrometry（FTIR）, 1H nuclear magnetic resonance（1H NMR） and gel permeation chromatography（GPC）. The cyclic voltammetry（CV） curve of PESOP reveals the reversible electroactivity. In the electrochromism study, PESOP film exhibited good electroch- romic properties with a high contrast value, moderate switching time and acceptable coloration efficiency. After running 1000 cycles, the PESOP/indium-tin oxide（ITO） electrochromic device remained unchanged except for the drifting of base line, which certified its good electro-photo stability of the fabricated electrochromic device. Moreover, the polarization technique and electrochemical impedance spectroscopy（EIS） were used to study the anticorrosion performance of PESOP coatings on the cold rolled steel（CRS） in a 5%（mass fraction） NaCI solution. All the results indicate that the obtained PESOP is a competitive candidate as anticorrosion material.展开更多
文摘针对表面肌电信号(s EMG)信号微弱、频率低、极易受到干扰的特点,设计了具有高共模抑制比、放大增益灵活可调、具有良好抗噪声性能的s EMG信号采集电路。信号的放大部分采用两级放大方案,以避免噪声被过分放大造成肌电信号被淹没的问题。带通滤波器部分由两组5阶Sallen-Key低通和高通滤波电路级联而成,阻带下降速度很快,近似达到-100 d B/(°),对噪声及其他生理电信号干扰的衰减能力极强。针对工频干扰问题,在陷波器部分设置Q值调节电位器,根据实测情况灵活调节电位器旋钮以便获取最佳采集效果。测试结果表明,所设计的电路放大增益可以达到60 d B,对50 Hz工频干扰有很好的抑制作用,可以有效提取20 Hz^500 Hz之间的有用信号,具有良好的抗噪声性能。
基金Science and Technology Plan Project of Weinan City(No.2020ZDYF-JCYJ-177)Power Supply Technology Innovation Team of Shaanxi Railway Engineering Vocational and Technical College(No.KJTD201901)Graduate Program Funded Project of Shaanxi Railway Engineering Vocational and Technical College Scientific Research Fund(No.KY2018-77)。
文摘A surface electromyography(sEMG)signal acquisition circuit based on high-order filtering is designed.We use a two-stage adjustable amplifier and a high-order Sallen-Key bandpass filter to solve the problems of non-adjustable amplification gain and low filtering order in traditional acquisition circuits.The experimental results show that the designed sEMG signal acquisition device can eliminate power frequency interference effectively,the stopband drop of the filtering part reaches approximately-100 dB/dec,which can effectively extract useful signals between 20-500 Hz,and the amplification gain reaches 60 dB.
基金Supported by the National Natural Science Foundation of China（No.21104024）, the Jilin Province Science and Technology Department Project, China（No.20130522139JH）, the Functional Research Funds for the Central Universities, China（No. JCKY-QKJC07） and the Open Project of State Key Laboratory of Superhard Materials（Jilin University）, China（No.201403）.
文摘A novel poly（ether sulfone） with oligoaniline pendants（PESOP） was prepared by KaCO3-mediated nucleophilic polycondensation and characterized with Fourier-transform infrared spectrometry（FTIR）, 1H nuclear magnetic resonance（1H NMR） and gel permeation chromatography（GPC）. The cyclic voltammetry（CV） curve of PESOP reveals the reversible electroactivity. In the electrochromism study, PESOP film exhibited good electroch- romic properties with a high contrast value, moderate switching time and acceptable coloration efficiency. After running 1000 cycles, the PESOP/indium-tin oxide（ITO） electrochromic device remained unchanged except for the drifting of base line, which certified its good electro-photo stability of the fabricated electrochromic device. Moreover, the polarization technique and electrochemical impedance spectroscopy（EIS） were used to study the anticorrosion performance of PESOP coatings on the cold rolled steel（CRS） in a 5%（mass fraction） NaCI solution. All the results indicate that the obtained PESOP is a competitive candidate as anticorrosion material.
