Journal of Magnetic Resonance, Series A最新文献_第8页

A Simple Method for the Delineation of Overlapping Lines in the EPR of Centers of DifferingT1. A Case Study Using CaF2Codoped with Gd3+, U3+ 差分t1中心EPR中重叠线圈定的一种简单方法caf2与Gd3+、U3+共掺杂的研究

Journal of Magnetic Resonance, Series A Pub Date : 1996-09-01 DOI: 10.1006/jmra.1996.0179

S.V. Godbole, M.D. Sastry

引用次数: 2

Deuterium Cross-Polarization Magic-Angle Spinning 氘交叉极化魔角旋转

Journal of Magnetic Resonance, Series A Pub Date : 1996-09-01 DOI: 10.1006/jmra.1996.0170

D. Marks , N. Zumbulyadis , S. Vega

{"title":"Deuterium Cross-Polarization Magic-Angle Spinning","authors":"D. Marks , N. Zumbulyadis , S. Vega","doi":"10.1006/jmra.1996.0170","DOIUrl":"10.1006/jmra.1996.0170","url":null,"abstract":"<div>In this publication a theoretical model is presented that describes cross-polarization magic-angle spinning (CPMAS) NMR experiments on a spin systemS(1)IN, consisting of a set ofNabundant homonuclear spins withI= <math><mtext>1</mtext><mtext>2</mtext></math> coupled to a single rare spin withS= 1. The spin evolution during this magic-angle spinning experiment is described using Floquet theory. The model is an extension of the formalism that was recently introduced to describe CPMAS ofS(<math><mtext>1</mtext><mtext>2</mtext></math>)INspin systems. First, experimental results of2H CPMAS experiments on partially deuterated dimethyl sulfone and malonic acid are shown. The rotational-echo intensities of the2H free-induction-decay signals were monitored and plotted as a function of the difference between the intensities of the RF fields applied on the deuterons and the protons during the mixing time. Then the Floquet description of a spin system withS= 1 is presented in order to enable the introduction of the Floquet model for CPMAS NMR. The Floquet Hamiltonian of the rotating quadrupolar spin is defined and the difference between spin locking in the rotating frame and in Floquet space is discussed. This is followed by a description of the spin evolution of theS(1)INsystem during CPMAS experiments. The modified Hartmann–Hahn conditions for these experiments are derived and a methodology for calculating the cross-polarization S-spin signal intensities is demonstrated. The discussion is restricted to spin-1 nuclei with relatively small quadrupole interactions and is directed toward2H CPMAS. S-spin signal intensities as a function of mismatched Hartmann–Hahn conditions are evaluated for powder samples with quadrupolar frequencies of 40 and 120 kHz.</div>","PeriodicalId":16165,"journal":{"name":"Journal of Magnetic Resonance, Series A","volume":"122 1","pages":"Pages 16-36"},"PeriodicalIF":0.0,"publicationDate":"1996-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1006/jmra.1996.0170","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84521147","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: 18

NMR Studies of Gallium Embedded in an Opal-like Porous Medium 类蛋白石多孔介质中镓的核磁共振研究

Journal of Magnetic Resonance, Series A Pub Date : 1996-09-01 DOI: 10.1006/jmra.1996.0176

E. Shabanova , E.V. Charnaya , K. Schaumburg, Yu.A. Kumzerov

引用次数: 7

The NMR MOUSE, a Mobile Universal Surface Explorer 核磁共振鼠标，一个移动通用表面Explorer

Journal of Magnetic Resonance, Series A Pub Date : 1996-09-01 DOI: 10.1006/jmra.1996.0185

G. Eidmann, R. Savelsberg, P. Blümler, B. Blümich

引用次数: 442

“Flow-Diffraction” Structural Characterization and Measurement of Hydrodynamic Dispersion in Porous Media by PGSE NMR “流动-衍射”结构表征及用PGSE NMR测量多孔介质中流体动力分散

Journal of Magnetic Resonance, Series A Pub Date : 1996-09-01 DOI: 10.1006/jmra.1996.0182

Joseph D. Seymour, Paul T. Callaghan

引用次数: 57

Optimizing Sudden Passage in the Earth's-Field NMR Technique 优化地场核磁共振技术中的突通

Journal of Magnetic Resonance, Series A Pub Date : 1996-09-01 DOI: 10.1006/jmra.1996.0172

B.F. Melton, V.L. Pollak

{"title":"Optimizing Sudden Passage in the Earth's-Field NMR Technique","authors":"B.F. Melton, V.L. Pollak","doi":"10.1006/jmra.1996.0172","DOIUrl":"10.1006/jmra.1996.0172","url":null,"abstract":"<div>The equation of motiondM/dt= γM × B(t) is solved numerically for the case B(t) = jBp(t) + kBe. The fieldBeis a small static field, typically the earth's field. The fieldBp(t) is a damped oscillation having frequency greater than, or on the order of, the precession frequency in fieldBe. Such oscillation inevitably occurs at the end of the rapid cutoff of the coil current used to polarize the sample. It is assumed thatBp(t) is initially large compared toBe, and that magnetization M is initially along the resultant field B. This is the usual situation in the earth's-field NMR technique when the polarizing field is produced by a coil of moderate to high impedance. It is shown that, when properly damped, the transient can be used to restore the magnetization to thex–yplane, thereby maximizing the amplitude of the subsequent free precession signal. The damping required is close to critical damping, so that the problem of circuit ringing when the coil is switched to receiver mode is also eliminated.</div>","PeriodicalId":16165,"journal":{"name":"Journal of Magnetic Resonance, Series A","volume":"122 1","pages":"Pages 42-49"},"PeriodicalIF":0.0,"publicationDate":"1996-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1006/jmra.1996.0172","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82358497","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

Investigation of the Magnetic Anisotropy in Manganese Ferrite Nanoparticles Using Magnetic Resonance 磁共振研究铁酸锰纳米颗粒的磁各向异性

Journal of Magnetic Resonance, Series A Pub Date : 1996-09-01 DOI: 10.1006/jmra.1996.0184

A.F. Bakuzis , P.C. Morais , F.A. Tourinho

引用次数: 17

Dispersion and Superheterodyne EPR Using a Bimodal Resonator 双峰谐振器的色散和超外差EPR

Journal of Magnetic Resonance, Series A Pub Date : 1996-09-01 DOI: 10.1006/jmra.1996.0174

George A. Rinard, Richard W. Quine, Barnard T. Ghim, Sandra S. Eaton, Gareth R. Eaton

引用次数: 29

Relative Sensitivity of Different Acquisition Schemes for13C Natural-Abundance HSQC Experiments 13c自然丰度HSQC实验中不同采集方案的相对灵敏度

Journal of Magnetic Resonance, Series A Pub Date : 1996-09-01 DOI: 10.1006/jmra.1996.0175

Jose A. Gavin , Jean L. Pons , Marc A. Delsuc

引用次数: 4

High-Temperature–High-Pressure NMR Probe for Self-Diffusion Measurements in Molten Salts 用于熔盐自扩散测量的高温高压核磁共振探针

Journal of Magnetic Resonance, Series A Pub Date : 1996-09-01 DOI: 10.1006/jmra.1996.0177

U. Matenaar, J. Richter, M.D. Zeidler

引用次数: 10