Abstract: The quadrature channels of an RF generator in an NMR spectrometer are aligned relative to one another by applying pulse sets to pairs of channels that are 180.degree. out of phase. The effect of the pulses in one channel is the opposite of the pulses in the other channel. As a result, the magnetization of the sample returns to the direction in which it started when the amplitudes of the pulses applied to each channel are equal. The magnetization returns to the initial direction even in the presence of RF inhomogeneities. The characteristic magnetization pattern can be easily observed and used to adjust the relative pulse amplitudes equal and the absolute pulse amplitudes to .pi./2.

Abstract: 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.

Abstract: An adapter is provided for a device which is used to pick up and transport objects. The device has a number of fingers which extend from a hollow piston. The adapter has an engaging portion which is inserted into the piston; a stopping piece for preventing the engaging piece from being inserted too far into the piston; and a receiving piece which has a cavity for receiving an object. The receiving piece and stopping piece each have openings which allow the fingers to pass through and grip the object while in the cavity.

Abstract: Apparatus and method for sequential provision of a series of similarly configured objects to and from a proximal location such as a device for testing those objects. The objects are provided in a gravity-fed ramp to an open cylindrical container provided with a centrally pivoting rotatable drum. The drum is provided with an indentation configured to receive only one of the objects at a time. The drum is rotatably disposed in the open cylinder about a central pivot to rotatably move the indentation between a first position of the open cylinder at the foot of the walled ramp and a second position of the open cylinder. At the second position, the open cylinder is provided with a drop tube. At the second position, the received object drops into the drop tube and thence into a supply tube that communicates at one of its ends to gravity feed the object to the proximal location where the object is to be utilized.

Abstract: A multiple-pulse RF pulse sequence reduces homonuclear dipolar coupling more efficiently relative to other known pulse sequences and is relatively insensitive to inhomogeneous RF fields, pulse imperfections and transmitter misadjustments so that it can be used on less sophisticated instruments and does not require long setup times. The inventive RF pulse sequence is constructed from selected sets of known six-pulse cycles called dipolar decoupled inversion pulses or composite inversion pulses. The dipolar decoupled inversion pulses are, in turn, constructed from standard solid echo pulse pairs. The six-pulse cycles are selected so that zero-order term of the average dipolar Hamiltonian is zero.

Abstract: In an NMR spectrometer, nuclear spins are subjected to a radio-frequency (RF) pulse sequence consisting of repeating cycles, each having a first and a second pulse set. The first pulse set generates a first large-amplitude rotation of the spins in which the angle through which the spins rotate varies with RF field strength. The second pulse set generates a second rotation which has an axis orthogonal to the first rotation axis and the angle through which the spins rotate is independent of the RF field strength. When the nuclear spins are placed in a non-homogeneous RF field and the above pulse sequence is applied, those spins which are located in an area where the RF field strength causes the first pulse set to rotate the spins through an angle which is a multiple of 2 .pi., the second, uniform rotation accumulates with each repetition of the first and second pulse sets in order to selectively excite those spins.

Abstract: A multiple-pulse RF pulse sequence applied in the presence of an oscillating magnetic field gradient enables slice selection in a magic angle spinning nuclear magnetic resonance solids imaging system. Slice selectivity is produced by a series of RF pulses, some of which introduce a nutation that coherently adds for only a selected slice plane of the sample and averages to zero in other areas and some of which average certain gradient-induced modulations so that only those object areas in the selected slice contribute to the output. The pulse train is applied in a manner synchronous with rotor rotation so that rotation induced modulations average to zero over one or more rotor rotation periods.

Abstract: Apparatus and method for sequential provision of a series of similarly configured objects to and from a proximal location such as a device for testing those objects. The objects are provided in a gravity-fed stack to a changer that includes a container, a holder slidably disposed in that container and configured to hold a limited number (such as one) of the objects, and a mover or driver for transporting the holder repeatedly between first and second positions within the container. In the first position, the holder is disposed under the stack of objects being fed to receive one of those objects. In the other position, the holder is positioned to gravity feed the object to the proximal location where the object is to be utilized. The holder can be configured with a single space, or with double parallel spaces, each of which can receive one object.

Abstract: The invention is a method and apparatus for performing high speed, high resolution nuclear magnetic resonance imaging wherein the magnetic coils for inducing the desired magnetic fields and receiving the magnetic field caused by NMR are positioned to one side of the volume under observation. Disclosed coil configurations provide a relatively large volume homogenous Ho field and three orthogonal gradient fields, so as to create a relatively large volume of observation which is broken up into high resolution voxels by appropriate selection of each of the gradient fields. The voxel is shifted in space at time intervals by scaling one or more of the gradient fields at such time intervals.

Abstract: 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.