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Field gradients

The change of magnetic field gradient s magnitude for this system is described by the dependence of... [Pg.879]

There are higher multipole polarizabilities tiiat describe higher-order multipole moments induced by non-imifonn fields. For example, the quadnipole polarizability is a fourth-rank tensor C that characterizes the lowest-order quadnipole moment induced by an applied field gradient. There are also mixed polarizabilities such as the third-rank dipole-quadnipole polarizability tensor A that describes the lowest-order response of the dipole moment to a field gradient and of the quadnipole moment to a dipolar field. All polarizabilities of order higher tlian dipole depend on the choice of origin. Experimental values are basically restricted to the dipole polarizability and hyperpolarizability [21, 24 and 21]. Ab initio calculations are an imponant source of both dipole and higher polarizabilities [20] some recent examples include [26, 22] ... [Pg.189]

Many other pulsed NMR experiments are possible, and some are listed in the final sections. Most can be canied out using the standard equipment described above, but some require additions such as highly controllable, pulsed field gradients, shaped RF pulses for (for example) single-frequency irradiations, and the combined use of pulses at several different frequencies. [Pg.1441]

The electric field gradient is again a tensor interaction that, in its principal axis system (PAS), is described by the tluee components F Kand V, where indicates that the axes are not necessarily coincident with the laboratory axes defined by the magnetic field. Although the tensor is completely defined by these components it is conventional to recast these into the electric field gradient eq = the largest component,... [Pg.1469]

Intramolecular quadrupolar 2 Reorientation of the electric field gradient principal axis Dominant for />1 (covalently bonded) [14]... [Pg.1506]

Intermolecular quadrupolar 2 Fluctuation of the electric field gradient, moving multipoles Common for />1 In free Ions In solution [la... [Pg.1506]

Motion, and in particular diffiision, causes a further limit to resolution [14,15]. First, there is a physical limitation caused by spins diflfiising into adjacent voxels durmg the acquisition of a transient. For water containing samples at room temperature the optimal resolution on these grounds is about 5 pm. However, as will be seen in subsequent sections, difhision of nuclei in a magnetic field gradient causes an additional... [Pg.1529]

Figure Bl.14.7. Chemical shift imaging sequence [23], Bothx- andj -dimensions are phase encoded. Since line-broadening due to acquiring the echo in the presence of a magnetic field gradient is avoided, chemical shift infonnation is retained in tire echo. Figure Bl.14.7. Chemical shift imaging sequence [23], Bothx- andj -dimensions are phase encoded. Since line-broadening due to acquiring the echo in the presence of a magnetic field gradient is avoided, chemical shift infonnation is retained in tire echo.
The displacement of a spin can be encoded in a manner very similar to that used for the phase encoding of spatial infonnation [28, 29 and 30]. Consider a spin j with position /-(t) moving in a magnetic field gradient G. The accumulated phase, cpj, of the spin at time t is given by... [Pg.1535]

Flow which fluctuates with time, such as pulsating flow in arteries, is more difficult to experimentally quantify than steady-state motion because phase encoding of spatial coordinate(s) and/or velocity requires the acquisition of a series of transients. Then a different velocity is detected in each transient. Hence the phase-twist caused by the motion in the presence of magnetic field gradients varies from transient to transient. However if the motion is periodic, e.g., v(r,t)=VQsin (n t +( )q] with a spatially varying amplitude Vq=Vq(/-), a pulsation frequency co =co (r) and an arbitrary phase ( )q, the phase modulation of the acquired data set is described as follows ... [Pg.1537]

B1.14.4.4 RESTRICTED DIFFUSION PULSED FIELD GRADIENT MICROSCOPY... [Pg.1541]

Luoas A J, Gibbs S J, Jones E W G, Peyron M, Derbyshire J A and Flail L D 1993 Diffusion imaging in the presenoe of statio magnetio-field gradients J. Magn. Reson. A 104 273-82... [Pg.1546]

Vector field gradient of the electrostatic potential, i.e., force... [Pg.403]

The PCM algorithm is as follows. First, the cavity siuface is determined from the van der Waals radii of the atoms. That fraction of each atom s van der Waals sphere which contributes to the cavity is then divided into a nmnber of small surface elements of calculable surface area. The simplest way to to this is to define a local polar coordinate frame at tlie centre of each atom s van der Waals sphere and to use fixed increments of AO and A(p to give rectangular surface elements (Figure 11.22). The surface can also be divided using tessellation methods [Paschual-Ahuir d al. 1987]. An initial value of the point charge for each surface element is then calculated from the electric field gradient due to the solute alone ... [Pg.612]

Electric field gradient q Exempli gratia (for example) e-g-... [Pg.102]

Finally, if the gas molecule possesses a quadrupole moment Q—examples are CO, COj and Nj—this will interact strongly with the field gradient F to produce a further contribution fQ to the energy. ... [Pg.7]

Electric-Field Gradients across the Glow Discharge... [Pg.35]


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Accurate Determination of Electric Field Gradients for Heavy Atoms and Molecules

Alternating Gradient Field Magnetometry (AGFM)

Anisotropy coupling , Electric field gradient

Calculations, field gradient

Calibrations pulsed field gradients

Coherence selection using pulsed field gradients

Coherence selection, pulsed field gradients

Coherence using pulsed field gradient

Combining Shaped Pulses and Pulsed Field Gradients Excitation Sculpting

Conduction field gradient from

Constant field gradient

Dielectric field gradient tensor

Diffusion Obstacles Inside the ZSM-5 Framework by Pulsed-Field Gradient NMR

Diffusion studies, magnetic field gradient

Distribution electric field gradients

Double-pulsed field gradient spin echo

Double-pulsed field gradient spin echo DPFGSE)

Electric Field Gradient Effects on Magnetic Susceptibility

Electric field gradient

Electric field gradient calculation

Electric field gradient components

Electric field gradient correlation

Electric field gradient description

Electric field gradient efg tensor

Electric field gradient expressions for transition metal elements

Electric field gradient fluctuations

Electric field gradient focusing

Electric field gradient geometry

Electric field gradient iron ions

Electric field gradient lattice contribution

Electric field gradient principles

Electric field gradient quadrupole interaction

Electric field gradient tensor

Electric field gradient tensor description

Electric field gradient tensor temperature dependence

Electric field gradient tensors computation

Electric field gradient tensors nuclear quadrupole coupling constant

Electric field gradient valence contribution

Electric field gradient, efg

Electric field gradients, point-charge model

Electric field strength gradient

Electric fields and field gradients

Electric-Field Gradients across the Glow Discharge

Electric-field-gradient tensor principal-axis system

Electric-field-gradient tensor quadrupolar coupling constant

Electric-field-gradient tensor quadrupolar interactions

Electric-quadrupole field-gradient

Electrical field gradient interaction

Electrical field gradient interaction quadrupole-inner

Electron field gradients

Electron spin resonance magnetic field gradients

Electronic charge density gradient vector field

Electronic distribution electric field gradients

Electrostatic field gradient

Field Gradient Methods

Field gradient NMR

Field gradient NMR techniques

Field gradient artifact suppression

Field gradient definition

Field gradient diffusion, measurements

Field gradient electrophoresis

Field gradient magnetic resonance imaging

Field gradient molecular

Field gradient operator

Field gradient resonance

Field gradient spin methods

Field gradient tensor element

Field gradient tensors

Field gradient, magnetic resonance

Field-Gradient Force Model

Field-gradient pulses gradients

Field-gradient spin-echo

Flow Parallel to Field or Interface Gradient

Fourier transform, pulsed-field gradient

Free field gradient

Free valence electric field gradient

Fringe-field gradient

Gradient field analysis

Gradient magnetic fields

Gradient of a scalar field

Gradient of a vector field

Gradient vector field

Gradient vector field of the charge density

Gradient vector field of the electron

Gradient vector field of the electron density

Gradient-field Raman scattering

Gradients multiconfiguration self-consistent field

Imaging magnetic field gradients

Internal field gradient

Interpretation and Computation of Electric Field Gradients

Ionic electric field gradient

Iron-57 compounds electric field gradient

Magnet magnetic field gradients

Magnetic field gradient calibration

Magnetic field gradient diffusion

Magnetic field gradient effects

Magnetic field-gradients pulsed

Magnetic field-gradients stationary

Magnetic-field gradient tensor

Magnetization in field gradients

Magnitude of the field gradient

Mass Transport in a Magnetic Field Gradient

Method using pulsed field gradient

Molecular Electric Fields and Field Gradients

Mossbauer electric field gradient

Mossbauer spectroscopy electric field gradient

Mossbauer spectroscopy electric field gradient interactions

NMR in polymers using magnetic field gradients imaging, diffusion and flow

NMR pulsed field gradient technique

Nuclear magnetic resonance pulsed field gradient

Nuclear magnetic resonance pulsed-field gradient spin-echo

Nuclear magnetic resonance spectroscopy pulsed field-gradient

Operator electric-field gradient

PFGSE (pulsed field gradient spin echo

Particle thermal gradient fields

Phase portraits of the gradient vector field

Practical Aspects of Pulsed Field Gradients and Shaped Pulses

Pressure gradient field

Pulse field gradient

Pulse field gradient -NMR methods

Pulse field gradient NMR

Pulse field gradient backbone

Pulse field gradient conformation

Pulse field gradient dipolar interaction

Pulse field gradient dynamics

Pulse field gradient method

Pulse field gradient nuclear magnetic

Pulse field gradient nuclear magnetic resonance

Pulse field gradient proteins

Pulse field gradient spin echo DPFGSE

Pulse field gradients, pulsed

Pulse-field gradient-stimulated echo

Pulse-field gradient-stimulated echo sequence

Pulse-field-gradient spin-echo

Pulse-field-gradient spin-echo technique

Pulsed field gradient

Pulsed field gradient NMR

Pulsed field gradient NMR measurement

Pulsed field gradient NMR spectroscopy

Pulsed field gradient echo formation

Pulsed field gradient experiments

Pulsed field gradient for coherence selection

Pulsed field gradient nuclear magnetic

Pulsed field gradient probe

Pulsed field gradient self

Pulsed field gradient self diffusion measurement

Pulsed field gradient spin echo

Pulsed field gradient spin-echo NMR

Pulsed field gradient spin-echo experiment

Pulsed field gradient-NMR experiments

Pulsed field gradients Subject

Pulsed field gradients application

Pulsed field gradients implementing

Pulsed field gradients in NMR

Pulsed field gradients observation

Pulsed field gradients shimming with

Pulsed field gradients signal selection

Pulsed field-gradient NMR methods

Pulsed high electrical field gradients

Pulsed-field gradient technology

Pulsed-field gradient-stimulated echo

Pulsed-field-gradient gel

Q, electric field gradient

Quadrupolar coupling electric field gradient

Quadrupole field gradient interactions

Related Methods Pulsed Field Gradient NMR and Dynamic Light Scattering

Selectivity Enhancement Using Magnetic Field Gradient Pulses

Self-consistent field dipole gradients

Self-consistent field molecular gradients

Semi-quantitative treatments of the electric field gradient

Signal selection with pulsed field gradients

Solvent suppression pulsed field gradients

Studying pulsed field gradient

The Electric Field Gradient eq Point Charge Model

The Problem of Nucleation in a Concentration Gradient Field

The electric field gradient

The pulsed field gradient echo (PFGE) NMR experiment

The quadrupole interaction and electric field gradients

Thermal gradient fields

Trajectories of the gradient vector field

Use of Pulsed Field Gradients

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