121 |
Resonances in P-C12 scattering.Singh, Raj Narain. January 1968 (has links)
No description available.
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122 |
Dynamic NMR studies of molecular motions and order in calamitic and discotic liquid crystalsZhang, Jing 14 September 2007 (has links)
This dissertation reports a study of three kinds of liquid crystals using modern solid state NMR techniques: chiral rod-like liquid crystals, bent-core mesogens and disc-like liquid crystals.
The properties and structures of liquid crystals are first introduced in Chapter 1. To understand the principles of different NMR phenomena, quantum mechanical theory is adopted to study different nuclear spin interactions and NMR techniques in Chapter 2.
In the next part of this dissertation (Chapter 3-6), deuterium NMR methods are used to investigate the dynamics and structures of some liquid crystal phases.
This is first done using the spin relaxation study. The parameters obtained from the model simulation can describe the molecular motion and internal dynamics in the fast motion region.
Secondly, we investigate the dynamic process of discotic mesophases and unwound smectic C* phase using the line shape simulation study.
2D deuterium NMR exchange experiments are then performed to study the jump process in TGBA* phase and SmC* phase.
The above investigation has demonstrated some powerful NMR methods for the dynamic study of liquid crystals.
The third part of the dissertation (Chapter 7-9) is concerned with C-13 NMR techniques.
After we introduce the quantum theory of different pulse sequences, theoretical models are presented to fit observations such as chemical shifts and dipolar splittings. Moreover high resolution liquid C-13 NMR experiments are introduced to study some bent-core molecules. They are useful to assist the carbon peak assignments of these molecules. The structure and ordering information of liquid crystals can be determined in their mesophases.
Finally, a brief summary of the dissertation is given in the last chapter.
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123 |
Solid-state NMR investigation of structure and dynamics of polyrotaxanesNagapudi, Karthik January 1997 (has links)
No description available.
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124 |
Magnetic resonance imaging of flow through a stenosis : accuracy of angiography and phase velocity measurementsSiegel, John Mather, Jr. 12 1900 (has links)
No description available.
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125 |
Evaluation of the accuracy of magnetic resonance phase velocity encoding in straight tubes and stenosesOshinski, John N. 05 1900 (has links)
No description available.
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126 |
RCHDCHDX compounds as stereochemical probes : INDO and UMINDO investigations of a test to distinguish erythro and threo diastereomersBloss, Richard E. January 1979 (has links)
This research has investigated the validity of a recently proposed test for distinguishing erythro and threo diastereomers of RCHDCHDX compounds on the basis of temperature dependent nmr spectra. INDO and UMINDO semiempirical molecular orbital calculations were used to calculate all nmr vicinal proton-proton coupling constants of a series of CH3CH2CH2X compounds (X = BH2, CH3, NH2, OH, F, PH2, SH, Cl). These data were used to predict the relative temperature dependence of the time-averaged vicinal proton-proton coupling constants of the corresponding CH3CHDCHDX` compounds.Standard bond lengths and angles were used for the input of trial geometries. Coupling constant data were obtained for molecules with no geometry optimization, optimization of the CH3CCX dihedral angle and total geometry optimization. All results suggest that the proposed test for distinguishing erythro and threo diastereomers of RCHDCHDX compounds is valid.
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127 |
Dynamic NMR studies of molecular motions and order in calamitic and discotic liquid crystalsZhang, Jing 14 September 2007 (has links)
This dissertation reports a study of three kinds of liquid crystals using modern solid state NMR techniques: chiral rod-like liquid crystals, bent-core mesogens and disc-like liquid crystals.
The properties and structures of liquid crystals are first introduced in Chapter 1. To understand the principles of different NMR phenomena, quantum mechanical theory is adopted to study different nuclear spin interactions and NMR techniques in Chapter 2.
In the next part of this dissertation (Chapter 3-6), deuterium NMR methods are used to investigate the dynamics and structures of some liquid crystal phases.
This is first done using the spin relaxation study. The parameters obtained from the model simulation can describe the molecular motion and internal dynamics in the fast motion region.
Secondly, we investigate the dynamic process of discotic mesophases and unwound smectic C* phase using the line shape simulation study.
2D deuterium NMR exchange experiments are then performed to study the jump process in TGBA* phase and SmC* phase.
The above investigation has demonstrated some powerful NMR methods for the dynamic study of liquid crystals.
The third part of the dissertation (Chapter 7-9) is concerned with C-13 NMR techniques.
After we introduce the quantum theory of different pulse sequences, theoretical models are presented to fit observations such as chemical shifts and dipolar splittings. Moreover high resolution liquid C-13 NMR experiments are introduced to study some bent-core molecules. They are useful to assist the carbon peak assignments of these molecules. The structure and ordering information of liquid crystals can be determined in their mesophases.
Finally, a brief summary of the dissertation is given in the last chapter.
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128 |
Developments in sulphur-33 and phosphorous-31 NMRCox, I. J. January 1984 (has links)
No description available.
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129 |
NMR studies of enzymes in situ and in vitroOxley, Simon T. January 1985 (has links)
No description available.
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130 |
Nuclear magnetic resonance relaxation in N-(p-methoxy-benzylidene)-p-butylaniline -carbon-tetrachloride mixturesHeldman, Margaret Anne. January 1979 (has links)
No description available.
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