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Pulsed-field gradient nuclear magnetic resonance as a tool for studying translational diffusion: part II. Experimental aspects 脉冲场梯度核磁共振作为研究平移扩散的工具:第二部分。实验方面
Concepts in magnetic resonance Pub Date : 1998-06-01 DOI: 10.1002/(SICI)1099-0534(1998)10:4<197::AID-CMR1>3.3.CO;2-5
W. S. Price
{"title":"Pulsed-field gradient nuclear magnetic resonance as a tool for studying translational diffusion: part II. Experimental aspects","authors":"W. S. Price","doi":"10.1002/(SICI)1099-0534(1998)10:4<197::AID-CMR1>3.3.CO;2-5","DOIUrl":"https://doi.org/10.1002/(SICI)1099-0534(1998)10:4<197::AID-CMR1>3.3.CO;2-5","url":null,"abstract":"In Part 1 of this series, we considered the theoretical basis behind the pulsed-field gradient nuclear magnetic resonance method for measuring diffusion. In this article the experimental and practical aspects of conducting such experiments are considered, including technical problems involved in gradient production such as eddy currents, gradient calibration, internal gradients in heterogeneous samples, and temperature control. Furthermore, the means for recognizing and preventing or at least minimizing these problems are discussed. A number of representative pulse sequences are also reviewed. ©1998 John Wiley & Sons, Inc. Concepts Magn Reson 10: 197–237, 1998","PeriodicalId":89665,"journal":{"name":"Concepts in magnetic resonance","volume":"61 4","pages":"197-237"},"PeriodicalIF":0.0,"publicationDate":"1998-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50680094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 338
Illustrating rotating-frame ( T 1 r ) NMR relaxation with a microcomputer 用微机说明旋转框架(t1 r)核磁共振弛豫
Concepts in magnetic resonance Pub Date : 1998-06-01 DOI: 10.1002/(SICI)1099-0534(1998)10:3<157::AID-CMR2>3.3.CO;2-9
Aleinandro C. Olivier
{"title":"Illustrating rotating-frame ( T 1 r ) NMR relaxation with a microcomputer","authors":"Aleinandro C. Olivier","doi":"10.1002/(SICI)1099-0534(1998)10:3<157::AID-CMR2>3.3.CO;2-9","DOIUrl":"https://doi.org/10.1002/(SICI)1099-0534(1998)10:3<157::AID-CMR2>3.3.CO;2-9","url":null,"abstract":"This paper is a continuation of previous works, in which QuickBasic computer programs are used to solve equations that describe the loss of quantum coherence in a two-state spin system, in the present case spin-locking conditions are applied. The coherence is considered to be lost by interaction with a randomly changing surrounding, modeled by the random-number generator of a microcomputer. The examples illustrate the behavior of rotating-frame relaxation time (T1ρ) as a function of correlation time (τ0). ©1998 John Wiley & Sons, Inc. Concepts Magn Reson 10: 157–166, 1998","PeriodicalId":89665,"journal":{"name":"Concepts in magnetic resonance","volume":"4 1","pages":"157-166"},"PeriodicalIF":0.0,"publicationDate":"1998-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50680047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Advanced solid-state NMR spectroscopy of strongly dipolar coupled spins under fast magic angle spinning 快速魔角旋转下强偶极耦合自旋的先进固体核磁共振谱
Concepts in magnetic resonance Pub Date : 1998-02-01 DOI: 10.1002/(SICI)1099-0534(1998)10:2<99::AID-CMR3>3.3.CO;2-6
S. Hafner, H. Spiess
{"title":"Advanced solid-state NMR spectroscopy of strongly dipolar coupled spins under fast magic angle spinning","authors":"S. Hafner, H. Spiess","doi":"10.1002/(SICI)1099-0534(1998)10:2<99::AID-CMR3>3.3.CO;2-6","DOIUrl":"https://doi.org/10.1002/(SICI)1099-0534(1998)10:2<99::AID-CMR3>3.3.CO;2-6","url":null,"abstract":"","PeriodicalId":89665,"journal":{"name":"Concepts in magnetic resonance","volume":"9 3","pages":"99-128"},"PeriodicalIF":0.0,"publicationDate":"1998-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50679980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 42
Contrast in solid-state NMR imaging, part I: principles 固态核磁共振成像中的对比，第一部分:原理
Concepts in magnetic resonance Pub Date : 1998-01-01 DOI: 10.1002/(SICI)1099-0534(1998)10:1<19::AID-CMR2>3.3.CO;2-I
B. Blümich
{"title":"Contrast in solid-state NMR imaging, part I: principles","authors":"B. Blümich","doi":"10.1002/(SICI)1099-0534(1998)10:1<19::AID-CMR2>3.3.CO;2-I","DOIUrl":"https://doi.org/10.1002/(SICI)1099-0534(1998)10:1<19::AID-CMR2>3.3.CO;2-I","url":null,"abstract":"Contrast is the central feature that makes NMR imaging of interest for materials applications. The principles of contrast in NMR imaging of solids are introduced and illustrated, based on the use of magnetization filters for preparation of thermodynamic nonequilibrium magnetization. ©1998 John Wiley & Sons, Inc. Concepts Magn Reson 10: 19–31, 1998","PeriodicalId":89665,"journal":{"name":"Concepts in magnetic resonance","volume":"6 4","pages":"19-31"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50679614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 19
Evaluation and interpretation of electron spin-echo decay, part 1: rigid samples 电子自旋回波衰减的评价和解释，第1部分:刚性样品
Concepts in magnetic resonance Pub Date : 1997-10-01 DOI: 10.1002/(SICI)1099-0534(1997)9:6<403::AID-CMR3>3.3.CO;2-H
M. Romanelli, L. Kevan
{"title":"Evaluation and interpretation of electron spin-echo decay, part 1: rigid samples","authors":"M. Romanelli, L. Kevan","doi":"10.1002/(SICI)1099-0534(1997)9:6<403::AID-CMR3>3.3.CO;2-H","DOIUrl":"https://doi.org/10.1002/(SICI)1099-0534(1997)9:6<403::AID-CMR3>3.3.CO;2-H","url":null,"abstract":"","PeriodicalId":89665,"journal":{"name":"Concepts in magnetic resonance","volume":"20 7","pages":"403-430"},"PeriodicalIF":0.0,"publicationDate":"1997-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50679739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 14
Strong coupling effects in 2D J , σ spectra: an application for the determination of the conformational isomes of some 1,4 disubstituted dioxanes 二维J， σ谱中的强耦合效应:用于测定一些1,4二取代二恶烷构象异构体的应用
Concepts in magnetic resonance Pub Date : 1997-10-01 DOI: 10.1002/(SICI)1099-0534(1997)9:6<359::AID-CMR1>3.3.CO;2-3
D. Traficante, M. Meadows
{"title":"Strong coupling effects in 2D J , σ spectra: an application for the determination of the conformational isomes of some 1,4 disubstituted dioxanes","authors":"D. Traficante, M. Meadows","doi":"10.1002/(SICI)1099-0534(1997)9:6<359::AID-CMR1>3.3.CO;2-3","DOIUrl":"https://doi.org/10.1002/(SICI)1099-0534(1997)9:6<359::AID-CMR1>3.3.CO;2-3","url":null,"abstract":"When strong proton–proton coupling is present, a projection of the tilted two-dimensional J, δ (J-resolved) spectrum frequently produces one or more extra lines, i.e., there are more lines in the projection than there are protons in the molecule. Contrary to popular belief, these lines are not “extraneous nuisances.” Instead, they may contain a wealth of information that can be of value for the determination of structural isomers. This article provides a brief introduction to the theory of these spectra and examines the origin as well as the practical properties of these extra transitions. Two important properties are: (a) in the untilted spectrum, the extra transitions have F2 frequencies that are equal to those of the normal transitions; and (b) they lie on a line that is midway between the lines that are formed by the normal transitions. As a practical application of the usefulness of these properties, this article presents the strategy used to identify several structural isomers of 2,5- and 2,6-disubstituted 1,4-dioxanes. All of the possible isomers were identified, including the separation of the “frozen” isomers from the equilibrating ones, and the separation of the 2,5- from the 2,6-disubstituted ones. The identification was achieved by measuring the coupling constants between the ring protons, and then using (a) the Karplus relationship to determine whether the substituent was axial or equatorial, and (b) the well-known planar-zigzag, or “W,” coupling to determine whether the substituents were both adjacent to only one of the ring oxygen atoms (the 2,6-isomer) or whether each was situated adjacent to only one ring oxygen atom (the 2,5-isomer). ©1997 John Wiley & Sons, Inc. Concepts Magn Reson 9: 359–384, 1997","PeriodicalId":89665,"journal":{"name":"Concepts in magnetic resonance","volume":"34 12","pages":"359-384"},"PeriodicalIF":0.0,"publicationDate":"1997-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50679819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 8
Illustrating transverse (T 2 ) NMR relaxation with a microcomputer 用微机说明横向(t2)核磁共振弛豫
Concepts in magnetic resonance Pub Date : 1997-08-01 DOI: 10.1002/(SICI)1099-0534(1997)9:5<337::AID-CMR3>3.0.CO;2-#
A. Olivieri
{"title":"Illustrating transverse (T 2 ) NMR relaxation with a microcomputer","authors":"A. Olivieri","doi":"10.1002/(SICI)1099-0534(1997)9:5<337::AID-CMR3>3.0.CO;2-#","DOIUrl":"https://doi.org/10.1002/(SICI)1099-0534(1997)9:5<337::AID-CMR3>3.0.CO;2-#","url":null,"abstract":"","PeriodicalId":89665,"journal":{"name":"Concepts in magnetic resonance","volume":"21 8","pages":"337-346"},"PeriodicalIF":0.0,"publicationDate":"1997-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/(SICI)1099-0534(1997)9:5<337::AID-CMR3>3.0.CO;2-#","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50679185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Pulsed-field gradient nuclear magnetic resonance as a tool for studying translational diffusion, part 1: basic theory 脉冲场梯度核磁共振作为研究平移扩散的工具，第一部分:基础理论
Concepts in magnetic resonance Pub Date : 1997-08-01 DOI: 10.1002/(SICI)1099-0534(1997)9:5<299::AID-CMR2>3.3.CO;2-2
W. S. Price
{"title":"Pulsed-field gradient nuclear magnetic resonance as a tool for studying translational diffusion, part 1: basic theory","authors":"W. S. Price","doi":"10.1002/(SICI)1099-0534(1997)9:5<299::AID-CMR2>3.3.CO;2-2","DOIUrl":"https://doi.org/10.1002/(SICI)1099-0534(1997)9:5<299::AID-CMR2>3.3.CO;2-2","url":null,"abstract":"Translational diffusion is the most fundamental form of transport in chemical and biochemical systems. Pulsed-field gradient nuclear magnetic resonance provides a convenient and noninvasive means for measuring translational motion. In this method the attenuation of the echo signal from a Hahn spin-echo pulse sequence containing a magnetic field gradient pulse in each τ period is used to measure the displacement of the observed spins. In the present article, the physical basis of this method is considered in detail. Starting from the Bloch equations containing diffusion terms, the (analytical) equation linking the echo attenuation to the diffusion of the spin for the case of unrestricted isotropic diffusion is derived. When the motion of the spin occurs within a confined geometry or is anisotropic, such as in in vivo systems, the echo attenuation also yields information on the surrounding structure, but as the analytical approach becomes mathematically intractable, approximate or numerical means must be used to extract the motional information. In this work, two common approximations are considered and their limitations are examined. Measurements in anisotropic systems are also considered in some detail. ©1997 John Wiley & Sons, Inc. Concepts Magn Reson 9: 299–336, 1997","PeriodicalId":89665,"journal":{"name":"Concepts in magnetic resonance","volume":"23 12","pages":"299-336"},"PeriodicalIF":0.0,"publicationDate":"1997-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50679132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 608
Relaxation in the presence of an rf field 在射频场存在下的弛豫
Concepts in magnetic resonance Pub Date : 1997-08-01 DOI: 10.1002/(SICI)1099-0534(1997)9:5<347::AID-CMR4>3.3.CO;2-4
W. E. Palke, J. T. Gerig
{"title":"Relaxation in the presence of an rf field","authors":"W. E. Palke, J. T. Gerig","doi":"10.1002/(SICI)1099-0534(1997)9:5<347::AID-CMR4>3.3.CO;2-4","DOIUrl":"https://doi.org/10.1002/(SICI)1099-0534(1997)9:5<347::AID-CMR4>3.3.CO;2-4","url":null,"abstract":"The equations that govern the relaxation of a system of nuclear spins in the presence of a radiofrequency (rf) field are studied with the aim of demonstrating the new features that the rf field introduces into the Redfield treatment of relaxation. It is shown under what conditions Redfield relaxation matrix elements reduce to the usual expressions in the absence of an rf field. The potential alteration of experimental relaxation rates by an rf field is considered. ©1997 John Wiley & Sons, Inc. Concepts Magn Reson 9: 347–353, 1997","PeriodicalId":89665,"journal":{"name":"Concepts in magnetic resonance","volume":"14 10","pages":"347-353"},"PeriodicalIF":0.0,"publicationDate":"1997-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50679385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 5
Adiabatic rf pulses: applications to in vivo NMR 绝热射频脉冲:在体内核磁共振中的应用
Concepts in magnetic resonance Pub Date : 1997-06-01 DOI: 10.1002/(SICI)1099-0534(1997)9:4<247::AID-CMR4>3.3.CO;2-A
R. D. Graaf, K. Nicolay
{"title":"Adiabatic rf pulses: applications to in vivo NMR","authors":"R. D. Graaf, K. Nicolay","doi":"10.1002/(SICI)1099-0534(1997)9:4<247::AID-CMR4>3.3.CO;2-A","DOIUrl":"https://doi.org/10.1002/(SICI)1099-0534(1997)9:4<247::AID-CMR4>3.3.CO;2-A","url":null,"abstract":"Adiabatic pulses are amplitude- and frequency-modulated pulses that are insensitive to the effects of B1-inhomogeneity and frequency offset. From the classical adiabatic passage experiments, the adiabatic condition is derived and analyzed. From the adiabatic condition, amplitude and frequency modulation functions are derived and optimized over predetermined radio frequency amplitude and frequency offset ranges. Description of the selective inversion and refocusing properties of adiabatic full-passage pulses leads to the principle of plane rotation pulses, of which the BIR-4 (B1-insensitive rotation) pulse will be discussed in detail. Theoretical simulations based on the Bloch equations, three-dimensional vector diagrams, and experimental applications demonstrate the utility and performance of the adiabatic pulses for in vivo NMR and for liquid state high-resolution NMR. ©1997 John Wiley & Sons, Inc. Concepts Magn Reson 9: 247–268, 1997","PeriodicalId":89665,"journal":{"name":"Concepts in magnetic resonance","volume":"38 9","pages":"247-268"},"PeriodicalIF":0.0,"publicationDate":"1997-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50679356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 67
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