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不知大家以前看到过没有，个人认为挺不错的
http://www.acornnmr.com/Sam/shimintro.htm

The Shimming of High Resolution NMR Magnets

By Virginia W. Miner and　Woodrow W. Conover


Table of Contents

Part I
Foreword In the olden days. Why is it called shimming?
Introduction What is shimming.
Equations for Common Room Temperature Shims Table showing field generated by common shims.
Sample Spinning Why samples are spun and the complications.

Part II
Basics What do we look at to shim.
Shim Interactions Procedure for adjusting shims with zero-, first- and second-order interactions.
A New Magnet Things which need to be checked when a magnet is installed.
Checking coil position A quick test for probe coil and shim coil alignment.
Before You Start To Shim Get off on the right foot.
Probe Coil Plot
A Shimming Procedure A systematic method of adjusting shims.

Part III
Symptoms of Inhomogeneity Lineshapes resulting from different axial gradients.

Part IV
The Z1 Profile Applying a gradient to display an axial "image" of the sample.
The Quickie Z1 Profile Approach to Shimming. Get Z3 and Z4 correct in a hurry.

Part V
The Sample and Shimming End effects, particulates, dissolved material, radiation damping.
Probes and Shimming Probe materials, magnetic susceptibility correction, size of the probe coil.
RF Homogeneity Origin of different types of spinning sidebands.
Computer Shimming Things to be aware of in using automatic shimming.