RLC谐振与物理共振的原理共性  

Similarity in principle of RLC and physical resonance

作　　者：李潮锐 LI Chao-rui(School of Physics,Sun Yat-sen University,Guangzhou 510275,China;National Demonstration Center for Experimental Physics Education,Sun Yat-sen University,Guangzhou 510275,China)

机构地区：[1]中山大学物理学院,广东广州510275 [2]中山大学物理国家级实验教学示范中心,广东广州510275

出　　处：《物理实验》2020年第12期21-27,43,共8页Physics Experimentation

基　　金：中山大学物理学人才培养支撑条件建设项目(No.J1210034);中山大学本科教学质量工程项目(No.2018WL-ZLJG026,No.2019WL-ZLJG004)。

摘　　要：描述RLC回路特性的二阶微分方程与受迫振动的动力学方程具有相似的物理涵义,后者可用于描述核磁共振物理原理,而前者则是核磁共振测量技术原理.可见,RLC谐振—经典振动—核磁共振三者存在明显的原理共性,而RLC谐振实验分析是理解共振物理原理的重要基础.通过回路电阻R所产生的阻尼作用,深入分析RLC谐振稳态频域和暂态时域特性及其物理涵义.频域半高全宽与暂态时域弛豫时间随阻尼变化关系提供了深刻理解核磁共振成像的物理基础.The second-order differential equation of RLC circuit has similar physics sense to the dynamic equation of forced vibration.The dynamic equation for vibration can be used to describe the physical principle of nuclear magnetic resonance(NMR),while the differential equation for RLC is the technology principle of NMR measurement.It could be seen that RLC resonance,mechanical vbration and NMR were obviously similar in theory,and RLC resonance experiment analysis was especially important for understanding their physical principles.By means of the damping effect of loop resistance R,the characteristics of RLC resonance in frequency-domains and time-domains,and their physical principles were analyzed.The relationship between the full width at half maximum in frequency-domain and the relaxation time in time-domainwith the change of damping provided a deep understanding on MRI.

关 键 词：受迫振动 核磁共振 弛豫时间 频率特性 

分 类 号：O321[理学—一般力学与力学基础] O482.532[理学—力学]