Bruker Instruments, Inc.

Anthony J Bielecki

Douglas P Burum

A method and apparatus precisely controlling the periodic motion of an object is specifically applicable to the control of the rotation of a nuclear magnetic resonance (NMR) spectrometer rotor, and uses a fluid source having a fluid output with a time-varying magnitude. The output of the fluid source is coupled to a stator housing within which the rotor is rotatably disposed such that the time varying fluid pressure from the fluid source impinges upon a plurality of vanes located about a circumference of the rotor. The coupling of the fluid flow to the rotor results in a periodicity of the rotor rotation being proportional to a periodicity of the time varying magnitude of the fluid flow. This, in turn, creates a plurality of stable equilibrium rotation rates at which a frequency locking effect is achieved that tends maintain the rotor periodicity at a predetermined rate, thereby achieving particularly precise and stable rotor rotation.

Method and apparatus for precisely controlling the periodic motion of an

A normal CPMAS experiment is modified to provide for spectral editing. In one embodiment of the invention, the conventional CPMAS experiment is performed with the proton decoupling RF applying at a frequency slightly different than the proton resonance frequency in order to suppress methylene (CH.sub.2) resonances more severely than CH and CH.sub.3 resonances. In another embodiment of the invention the RF pulse sequence normally using during the cross-polarization period is replaced with a WIM RF pulse sequence which has the effect of suppressing the CH and CH.sub.3 resonances, thereby leaving the CH.sub.2 resonances.

Method for editing CPMAS solid-state NMR spectra

A new RF pulse sequence is applied to selected nuclei in the evolution period of a 2D NMR heteronuclear correlation experiment to more effectively suppress heteronuclear interactions. The new pulse sequence is designed to be effective with the existing BLEW-12 pulse sequence so that both homonuclear and heteronuclear interactions are suppressed. In addition, the new pulse sequence effectively suppresses homonuclear interactions so that it can be used with a variety of nuclear species.

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Somerville, MA, United States of America

Anthony J Bielecki