连续波核磁共振吸收的频域测量

Measurement of continuous wave nuclear magnetic resonance in frequency-domain

目前连续波和脉冲核磁共振实验教学普遍侧重于时域观测.针对该问题,在原有主体设备环境中,配合通用仪器实施核磁共振吸收的频域测量.由稳压源输出提供变容二极管偏压而调节振荡频率,利用交流信号源简谐励磁电流调制磁场,采用锁相放大技术实现核磁共振吸收频域微分测量.实验结果直观准确地显示了同一物质在相同实验环境中核磁共振吸收的时域和频域特性.本工作不仅拓展了实验教学内容并加深对实验技术的理解,也为不同对象的个性化学习需要提供层次化教学环境.

Now the teaching experiments of continuous wave and pulsed NMR generally focus on time-domain measurement.With the original main equipment,frequency-domain measurement of NMR was carried out by adding some universal instruments.The voltage from regulator source was supplied to adjust the oscillation frequency,and the harmonic current from an alternating current source was used to modulate the magnetic field.The phase-locked amplification technique was adopted to perform differential measurement of NMR in frequency domain.The experimental results showed that the time-domain and frequency-domain characteristics of NMR could be measured in the almost same experimental environment.This work not only expanded the teaching content of the experiments and deepened the understanding of experimental technology,but also provided a multi-level teaching environment for personalized learning.