A CW NMR spectrometer functions by irradiating each set of distinct nuclei in turn, a process analagous to striking each chime independently. For a high resolution spectrum this must be done slowly, and a 12 ppm sweep of the proton region takes from 5 to 10 minutes.

连续波（continuous wave;CW)是指射频的频率或外磁场的强度是连续变化的，即进行连续扫描，一直到被观测的核依次被激发发生核磁共振。 [1] 仪器组成

Book on NMR. Overview. In this experiment you will observe nuclear magnetic resonance using a radio frequency (RF) field applied to a proton sample placed in a large DC magnetic field with a small AC component. As the sample passes through resonance the RF field flips the proton spins from the ground state to the excited state.

核磁共振波谱法 （Nuclear Magnetic Resonance，简写为 NMR ）是材料表征中最有用的一种仪器测试方法，它与 紫外吸收光谱 、 红外吸收光谱 、 质谱 被人们称为“四谱”，广泛应用于物理学、化学、生物、药学、医学、农业、环境、矿业、材料学等学科，是对各种 ...

What we call “nuclear magnetic resonance” (NMR) was developed simultaneously but indepen-dently by Edward Purcell and Felix Bloch in 1946. The experimental method and theoretical interpretation they developed is now called “continuous-wave NMR” (CWNMR). A different ex-

This is the method of continuous wave nuclear magnetic resonance, or CW NMR, an experiment which you have already completed. An alternative method to this steady state or slow passage technique is one in which the radio frequency field is applied to the sample in short intense pulses, and nuclear signals are observed after the pulses are removed.

Continuous Nuclear Magnetic Resonance (CW-NMR) In this experiment students observe nuclear magnetic resonance using very simple electronics and experimental hardware. A radio frequency (rf) field is applied to a proton sample placed in a large DC magnetic field with a …

There are two ways to do NMR spectroscopy: Continuous Wave NMR (CW-NMR) and Fourier Transform NMR (FT-NMR). In the CW-NMR instrument, one frequency is scanned at a time and the signal for that certain frequency will be detected. In FT-NMR instruments, a pulse containing a wide range of frequencies is applied and one signal for all nuclei is ...

Pulsed NMR experiments provide a rich “intellectual phase-space”, bringing together important aspects of classical mechan-ics (torque, angular momentum, precession), quantum mechanics (time-dependent perturbation, stimulated emission, superposition of states), statistical mechanics (density matrix and relaxation), electricity and magnetism (Far...

高分子材料的nmr成像技术. 核磁共振成像技术已成功地用来探测材料内部的缺陷或损伤，研究挤塑或发泡材料，粘合剂作用，孔状材料中孔径分布等。可以被用来改进加工条件，提高制品的质量。 多组分材料分析