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2
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Application of High-Resolution Solid-State NMR with Cross-Polarization/Magic-Angle Spinning (CP/MAS) Techniques to Cellulose Chemistry. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/07366578308079442] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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3
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Influence of fluorine content on the composition of Al-rich synthetic phlogopite investigated by solid state NMR. Acta Crystallogr A 2002. [DOI: 10.1107/s0108767302098379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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4
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High-resolution carbon-13 CP/MAS NMR spectra of solid cellulose oligomers and the structure of cellulose II. J Am Chem Soc 2002. [DOI: 10.1021/ja00346a059] [Citation(s) in RCA: 127] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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5
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Investigation of the conversion (dealumination) of ZSM-5 into silicalite by high-resolution solid-state silicon-29 and aluminum-27 MAS NMR spectroscopy. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j150659a023] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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6
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High-resolution carbon-13 and nitrogen-15 NMR investigations of the mechanism of the curing reactions of cyanate-based polymer resins in solution and the solid state. Macromolecules 2002. [DOI: 10.1021/ma00049a028] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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7
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8
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High-Resolution Carbon-13 Nuclear Magnetic Resonance Studies of Polymers in the Solid State. Aromatic Polyesters. Macromolecules 2002. [DOI: 10.1021/ma60070a044] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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9
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Studies of phosphorus(III) ligands and their complexes of nickel(II), palladium(II), and platinum(II) immobilized on insoluble supports by high-resolution solid-state phosphorus-31 NMR using magic-angle spinning techniques. J Am Chem Soc 2002. [DOI: 10.1021/ja00366a011] [Citation(s) in RCA: 125] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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10
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A highly siliceous structural analog of zeolite Y: high-resolution solid-state silicon-29 and aluminum-27 NMR studies. Inorg Chem 2002. [DOI: 10.1021/ic00143a016] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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11
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Pulsed nuclear magnetic resonance study of the molecular dynamics of fluxional organometallic molecules in the solid state. 2. Complexes containing .eta.1 (.sigma.-bonded) cyclopentadienyl rings. Inorg Chem 2002. [DOI: 10.1021/ic50160a016] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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12
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Investigations of polymer-supported complexes of platinum(II) by high-resolution solid-state phosphorus-31 NMR spectroscopy employing magic-angle spinning and cross-polarization techniques. Organometallics 2002. [DOI: 10.1021/om00073a040] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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13
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Demonstration of the liquid-crystalline behavior of a rigid-backbone polyester in a magnetic field. Macromolecules 2002. [DOI: 10.1021/ma00031a043] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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14
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Direct Solid-State 13C NMR Evidence for Covalent Bond Formation between an Immobilized Vinylsilane Linking Agent and Polymer Matrixes. Macromolecules 2002. [DOI: 10.1021/ma00115a020] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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15
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16
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Natural-abundance two-dimensional silicon-29 MAS NMR investigation of the three-dimensional bonding connectivities in the zeolite catalyst ZSM-5. J Am Chem Soc 2002. [DOI: 10.1021/ja00180a024] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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17
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Molecular dynamics of fluxional molecules in the solid state. Cyclooctatetraene-iron carbonyl complexes. J Am Chem Soc 2002. [DOI: 10.1021/ja00763a023] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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18
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Molecular dynamics of fluxional molecules in the solid state. Organometallic complexes containing monohapto (.sigma.-bonded) cyclopentadienyl rings. J Am Chem Soc 2002. [DOI: 10.1021/ja00779a017] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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19
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Flow nuclear magnetic resonance investigation of the intermediates formed by the attack of alkoxide ions on substituted pyridinium ions. J Org Chem 2002. [DOI: 10.1021/jo01325a001] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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20
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Applications of magic-angle-spinning silicon-29 nuclear magnetic resonance. Evidence for two different kinds of silicon-aluminum ordering in zeolitic structures. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j150618a003] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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21
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Application of High-Resolution 13C NMR Spectroscopy Using Magic Angle Spinning Techniques to the Direct Investigation of Solid Cured Phenolic Resins. Macromolecules 2002. [DOI: 10.1021/ma60077a059] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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22
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23
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Pulsed nuclear magnetic resonance study of the molecular dynamics of fluxional organometallic molecules in the solid state. 1. Complexes containing cyclooctatetraene ligands. Inorg Chem 2002. [DOI: 10.1021/ic50160a015] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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24
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25
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Characterization of the crystalline A and B starch polymorphs and investigation of starch crystallization by high-resolution carbon-13 CP/MAS NMR. Macromolecules 2002. [DOI: 10.1021/ma00158a016] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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26
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Polymer-immobilized complexes of platinum(II): their precursors and preparation studied by high-resolution solid-state phosphorus-31 NMR using magic-angle spinning techniques. J Am Chem Soc 2002. [DOI: 10.1021/ja00360a007] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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27
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Nuclear magnetic resonance investigation of the adducts formed by the attack of carbanions on substituted pyridinium ions. J Org Chem 2002. [DOI: 10.1021/jo01325a002] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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28
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High-resolution carbon-13 nuclear magnetic resonance spectra of frozen liquids using magic angle spinning. J Am Chem Soc 2002. [DOI: 10.1021/ja00486a009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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29
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Coherence transfer involving quadrupolar nuclei in solids: aluminum-27 .tautm. phosphorus-31 cross-polarization NMR in the molecular sieve VPI-5. J Am Chem Soc 2002. [DOI: 10.1021/ja00040a069] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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30
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Natural abundance, two-dimensional silicon-29 MAS NMR investigation of the three-dimensional bonding connectivities in the high- and low-temperature forms of zeolite ZSM-11. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100162a057] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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31
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An alternative preparation of organofunctionalized silica gels and their characterization by two-dimensional high-resolution solid-state heteronuclear NMR correlation spectroscopy. J Am Chem Soc 2002. [DOI: 10.1021/ja00035a014] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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32
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Dipolar-Based 27Al .fwdarw. 29Si Solid-State NMR Connectivity Experiments in Zeolite Molecular Sieve Frameworks. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100021a041] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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33
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High resolution carbon-13 NMR studies of chemical exchange processes in the solid state using magic angle spinning. J Am Chem Soc 2002. [DOI: 10.1021/ja00499a085] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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34
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Increased Efficiency of Coherence Transfer in Cross-Polarization NMR from Quadrupolar Nuclei: Dynamic-Angle Cross-Polarization. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100059a028] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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35
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Solid-state magic-angle spinning. Aluminum-27 nuclear magnetic resonance studies of zeolites using a 400-MHz high-resolution spectrometer. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100397a006] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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36
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High-resolution silicon-29 nuclear magnetic resonance spectrum of zeolite ZK-4: its significance in assessing magic angle spinning nuclear magnetic resonance as a structural tool for aluminosilicates. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100213a003] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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37
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Investigation of the crystalline "V" amylose complexes by high-resolution carbon-13 CP/MAS NMR spectroscopy. Macromolecules 2002. [DOI: 10.1021/ma00178a010] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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38
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Solid-state phosphorus-31 NMR investigations of phosphido-bridged complexes: chemical shift bond angle correlations. Inorg Chem 2002. [DOI: 10.1021/ic00321a016] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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39
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Three-dimensional lattice connectivities from two-dimensional high-resolution solid-state NMR. Silicon-29 magic angle spinning NMR investigation of the silicate lattice of zeolite ZSM-39 (Dodecasil 3C). J Am Chem Soc 2002. [DOI: 10.1021/ja00202a006] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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40
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41
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Solid-state double-resonance NMR experiments involving quadrupolar and spin 1/2 nuclei. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100153a012] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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42
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Investigation of the thermal degradation of poly(acrylic acid) and poly(methacrylic acid) by high-resolution carbon-13 CP/MAS NMR spectroscopy. Macromolecules 2002. [DOI: 10.1021/ma00161a021] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Crystal structure of silica-ZSM-12 by the combined use of hgh-resolution solid-state MAS NMR spectroscopy and synchrotron x-ray powder diffraction. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100372a066] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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45
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Proton NMR method for the quantitative determination of the water content of the polymeric fluorosulfonic acid Nafion-H. Macromolecules 2002. [DOI: 10.1021/ma00156a015] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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46
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Harvesting and climate effects on organic matter characteristics in British Columbia coastal forests. JOURNAL OF ENVIRONMENTAL QUALITY 2002; 31:402-413. [PMID: 11931427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
As part of investigations into the effects of harvesting old-growth forest, we characterized carbon in five organic matter pools in eight forest chronosequences of coastal British Columbia. Each chronosequence comprised stands in four seral stages from regeneration (3-8 yr) to old-growth (>250 yr), with second-growth stands mostly of harvest origin. Stands were located in two biogeoclimatic subzones with contrasting climate (wetter, slightly cooler conditions on the west coast of Vancouver Island than on the east). Carbon concentrations in fine woody debris (FWD), forest floor (LFH), fine roots from LFH, and two water-floatable fractions from 10 to 30 cm mineral soil (MIN-ROOT, 2-8 mm and MIN-FLOAT, <2 mm) showed no significant effects due to climate, seral stage, or site. There were some significant differences in N concentrations, but none related to seral stage. Carbon-13 cross-polarization with magic-angle spinning (CPMAS) nuclear magnetic resonance (NMR) spectra with principal component analysis of relative areas also showed little harvesting effect, but greater variation related to input of coarse woody debris (CWD) vs. roots high in tannin. Overall, there tended to be more spectral features associated with wood and lignin in the west; whereas some MIN-ROOT samples from the drier east side had aromatic intensity attributed to charcoal. The minimal effects of one harvest on organic matter are most likely due to the large legacy effect; however, more intensive management will probably result in less CWD retention, less charcoal input, and less microsite variability in these pools of poorly decomposed organic matter.
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Investigation of Slow Molecular Motions and Chemical Exchange in the High Loaded Form of p-Xylene in ZSM-5 by Two-Dimensional 13C Solid-State NMR Exchange Experiments. J Phys Chem B 2002. [DOI: 10.1021/jp0129028] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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48
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Solid-state NMR characterization of the mineral searlesite and its detection in complex synthesis mixtures. Inorg Chem 2001; 40:5906-12. [PMID: 11681903 DOI: 10.1021/ic010487s] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The mineral searlesite (NaBSi(2)O(5)(OH)(2)) was synthesized and characterized by (1)H, (11)B, (23)Na, and (29)Si magic-angle spinning (MAS) NMR spectroscopy. From these spectra, the (11)B and (23)Na quadrupole coupling parameters and isotropic chemical shifts and the (29)Si chemical shift anisotropies have been precisely determined. These parameters are all consistent with the local environments obtained from the crystal structure for searlesite from X-ray diffraction, and they demonstrate that the synthetic sample has a high degree of both short- and long-range order. Furthermore, these anisotropic parameters are found to provide a unique fingerprinting of searlesite in complex mixtures where the presence of this mineral is not anticipated. This is demonstrated for product mixtures formed in attempts to incorporate boron in the structures of the layer silicates magadiite and kenyaite. These mixtures have been investigated by (11)B, (23)Na, and (29)Si MAS NMR which clearly reveal that the samples are mixtures of searlesite and magadiite/kenyaite and that searlesite production consumes all of the boron in these synthesis mixtures. However, the (29)Si MAS NMR spectra of these mixtures indicate that the presence of boron in the reaction mixtures nevertheless has an important influence on the quality of the magadiite and kenyaite layer silicates produced.
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Solid-state NMR detection, characterization, and quantification of the multiple aluminum environments in US-Y catalysts by (27)Al MAS and MQMAS experiments at very high field. J Am Chem Soc 2001; 123:5285-91. [PMID: 11457391 DOI: 10.1021/ja003210k] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The detection of all of the aluminum present in steamed zeolite H-Y catalysts by (27)Al MAS NMR at 14.4 T (600 MHz for (1)H) and 18.8T (800 MHz for (1)H) is reported. Further, it is shown that it is possible by (27)Al MAS and MQMAS NMR measurements to clearly identify four separate aluminum environments which are characteristic of these materials and to unambiguously assign their coordinations. Average chemical shift and quadrupolar coupling parameters are used to accurately simulate the (27)Al MAS NMR spectra at 9.4 T (400 MHz for (1)H), 14.4 T (600 MHz for (1)H) and 18.8 T (800 MHz for (1)H) in terms of these four aluminum environments. In addition, these average chemical shift and quadrupolar coupling parameters are used to calculate peak positions in the (27)Al MQMAS isotropic dimension that are in good agreement with the experimental data acquired at 9.4 and 18.8 T.
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Quantitative NMR imaging study of the mechanism of drug release from swelling hydroxypropylmethylcellulose tablets. J Control Release 2000; 68:313-33. [PMID: 10974386 DOI: 10.1016/s0168-3659(00)00245-5] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
NMR imaging has been used to study the release behavior of two model drugs, triflupromazine-HCl and 5-fluorouracil, from swelling hydroxypropylmethylcellulose (HPMC) tablets. Preliminary experiments were performed on equilibrium mixtures of drug, polymer and water to determine how properties such as NMR relaxation parameters and self-diffusion were affected by the drug and polymer concentrations. The tablet swelling was restricted to one dimension and distributions of the water and model drugs were obtained by 1H and 19F imaging, respectively. The HPMC distribution at each time in the swelling process was determined indirectly from its effect on the relaxation parameters of the water and the drugs. In the one-dimensional swelling tablet, distributions of drug and polymer were compared to determine what factors influenced the release of drug from the swelling tablet. The distributions for triflupromazine-HCl and HPMC paralleled each other and the drug was only released at the eroding edge of the tablet where the HPMC concentration dropped below 10%. In contrast, 5-fluorouracil was released much more rapidly from the tablet and appeared to escape by diffusion from regions as high as 30% HPMC. An empirical measure of the rate of tablet edge movement can be obtained from plots of the edge position as a function of the square root of time. For HPMC, the rate of tablet expansion was determined in this way to be (2.4+/-0.8)x10(-6) cm(2) s(-1). The self-diffusion of triflupromazine-HCl in equilibrated mixtures of similar composition to the eroding tablet edge is approximately 3x10(-6) cm(2) s(-1) while the self-diffusion coefficient of 5-fluorouracil remained higher than this value until the HPMC concentration reached about 30%. This comparison of 'diffusion' properties may be useful in predicting the mechanism of drug release from other swelling hydrophilic matrix systems.
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