核磁经典教程

核磁经典教程Tag内容描述：<p>1、5How the spectrometer works NMR spectrometers have now become very complex instruments capable of performing an almost limitless number of sophisticated experiments How ever the really important parts。</p><p>2、1 Exercises for Chapters 6 7 8 you may ignore the evolution due to coupling E6 9 Express 2 12 I I xy in terms of raising and lowering operators see section 6 5 2 Take the zero quantum part of your exp。</p><p>3、4Fourier transformation and data processing In the previous chapter we have seen how the precessing magnetization can be detected to give a signal which oscillates at the Larmor frequency the free ind。</p><p>4、2NMR and energy levels E2 E1 h E2 E1 energy levels spectrum Fig 2 1 A line in the spectrum is associated with a transition between two energy levels The picture that we use to understand most kinds of。</p><p>5、8 1 8 Relaxation Relaxation is the process by which the spins in the sample come to equilibrium with the surroundings At a practical level the rate of relaxation determines how fast an experiment can。</p><p>6、9 1 9 Coherence Selection Phase Cycling and Gradient Pulses 9 1 Introduction The pulse sequence used in an NMR experiment is carefully designed to produce a particular outcome For example we may wish。</p><p>7、3The vector model For most kinds of spectroscopy it is suffi cient to think about energy levels and selection rules this is not true for NMR For example using this energy level approach we cannot even。</p><p>8、6 1 6 Product Operators The vector model introduced in Chapter 3 is very useful for describing basic NMR experiments but unfortunately is not applicable to coupled spin systems When it comes to two di。</p><p>9、7 1 7 Two dimensional NMR 7 1 Introduction The basic ideas of two dimensional NMR will be introduced by reference to the appearance of a COSY spectrum later in this chapter the product operator formal。</p>