阻抗微生物检测过程中的等效电路模型及各阻抗参数变化  

The Equivalent Circuit Model and Changes of Impedance Parameters during Impedance Microbial Detection

作　　者：张爱萍[1] 吴丹[1] 侯式娟[2] 唐佳妮[1] 刘东红[1] 

机构地区：[1]浙江大学生物系统工程与食品科学学院,杭州310029 [2]烟台大学化学生物理工学院,山东烟台264005

出　　处：《中国食品学报》2011年第2期185-191,共7页Journal of Chinese Institute Of Food Science and Technology

基　　金：十一五国家科技支撑课题(2009BADB9B06)

摘　　要：应用等效电路的研究方法分析了利用双电极进行阻抗微生物检测时,测试管内的等效电路。通过分析Bode图,得到测试管内的总阻抗包含不随频率变化的电导、随频率呈指数变化的电导、随频率呈指数变化的阻抗虚部3项。结合检测过程中的Nyquist图,得到测试管的等效电路为常相位角元件(CPE)与电阻R的串联。用matlab进行参数估计,得到等效电路的模型:Z=11.423+1.3704×104×ω-0.7767×cos(0.7767π2)-j1.3704×104×ω-0.7767×sin(0.7767π2)。本文还研究了双电层电容(Cs)、电导(G)、总阻抗(Z)、阻抗角(θ)在微生物生长过程中的变化及其变化比率。Cs、G增大,Z、θ减小,Cs、G、Z、θ变化比率的趋势一致,但变化比率的幅值不同,Cs幅值最大,Z最小。In this paper,the equivalent circuit of the test tube during impedance microbiological detection was analyzed by the equivalent circuit method,obtaining that the total impedance containing the constant conductance,the conductance changed exponentially with frequency and the imaginary part of impedance changed exponentially with frequency through analyzing the Bode diagram.Combined with the Nyquist diagram the equivalent circuit of the test tube was the constant phase angle element（CPE） in series with the resistor R.Finally,getting the equivalent circuit model using matlab：Z = 11.423＋1.3704×104×ω-0.7767×cos（0.7767π2）-j1.3704×104×ω-0.7767×sin（0.7767π2）.Meanwhile,this paper also studied the changes and the rate of changes of the electric double-layer capacitance（Cs）,the conductance（G）,the total impedance（Z）,the impedance angle（θ） during microbial growth-Cs,G increases,Z,θ decreases;the trend of the changes rate of Cs,G,Z,θ was the same,but the amplitude of the changes rate were different-Cs was the maximum,while Z was minimum.

关 键 词：阻抗微生物 等效电路 阻抗参数 变化 

分 类 号：TS207.4[轻工技术与工程—食品科学]