这类方法主要解决低旋磁比和低自然丰度核的NMR灵敏皮的提高问题,也能用于决定偶合常数的相对符号。一、灵敏度提高的非选择性方法采用一种磁极化转移的方法,利用质子的粒子数,在能级间Boltzmann分布的差比其它旋磁比小的核要大。 This kind of method mainly solves the problem of raising the sensitive skin with low gyromagnetic ratio and low natural abundance nucleus, and can also be used to determine the relative sign of the coupling constant. A nonselective method with improved sensitivity uses a method of magnetic polarization transfer. Using the number of proton particles, the difference in Boltzmann distribution between energy levels is larger than that of other small spintrons.