摘要:

AbstractGeneral information is given about solenoidal superconducting magnets and an overview is given of the design principles and theories for superconducting magnets. Issues relevant to NMR are reviewed in detail. Advantages and disadvantages of different superconducting wire, construction methods, and mathematical concepts necessary for the main components of a superconducting magnet applicable to high‐resolution NMR are surveyed. Major components such as joints, dump resistors, heat shields, and magnet dewars are illustrated and describe

ISSN:1043-7347    

DOI:10.1002/cmr.1820060402

出版商:John Wiley&Sons, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractConservation, creation, and destruction of polarization in nuclear magnetic polarization‐transfer experiments are discussed. In general, polarization is not conserved during NMR pulse experiments, although a useful reciprocity relation is formulated. The features of polarization‐transfer experiments are illustrated by liquid‐ and solid‐st

ISSN:1043-7347    

DOI:10.1002/cmr.1820060403

出版商:John Wiley&Sons, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractTwo‐dimensional heteronuclear correlation spectroscopy between the spin pairs13C,nX (withnX =2H,6Li,11B,15N,19F,29Si,31P,77Se,119Sn,125Te,195Pt,199Hg, and207Pb) is discussed. The necessary hardware requirements are explained, and the three most important correlation techniques are compared using product operator formalism. Selected simple examples demonstrate the usefulness of this new metho

ISSN:1043-7347    

DOI:10.1002/cmr.1820060404

出版商:John Wiley&Sons, Inc.    

年代:1994

数据来源: WILEY

摘要:

Abstract1H‐1H homonuclear correlated spectroscopy (COSY) cross peaks are detected at high fields in the case of paramagnetic macromolecular systems, even between signals with linewidths of 103hertz. Because they cannot be ascribed toJ‐coupling effects, we began to look for novel or undiscovered physical phenomena. Cross correlation occurs between proton‐proton dipolar coupling and Curie spin‐nuclear spin relaxation. The effect on a dipolar coupled AX system is that each signal is made up of two overlapped components with different linewidths. The cross correlation produces antiphase coherence that generates COSY cross peaks when a 90° ‐t1−90°‐t2experiment is performed, even though the phase of the cross peak with respect to a normalJ‐coupling scheme is different. Here, a theoretical derivation of the effect is given. Because the observation of this cross‐correlation effect is absolutely general in paramagnetic metalloproteins, the pulse sequences that quench the effect are shown. It also is stressed that it would be desirable to quench concomitantJ‐coupling effects and to detect cross peaks that result only from cross‐correlation effects; a sequence t

ISSN:1043-7347    

DOI:10.1002/cmr.1820060405

出版商:John Wiley&Sons, Inc.    

年代:1994

数据来源: WILEY

ISSN:1043-7347    

DOI:10.1002/cmr.1820060406

出版商:John Wiley&Sons, Inc.    

年代:1994

数据来源: WILEY

ISSN:1043-7347    

DOI:10.1002/cmr.1820060407

出版商:John Wiley&Sons, Inc.    

年代:1994

数据来源: WILEY

ISSN:1043-7347    

DOI:10.1002/cmr.1820060408

出版商:John Wiley&Sons, Inc.    

年代:1994

数据来源: WILEY

ISSN:1043-7347    

DOI:10.1002/cmr.1820060401

出版商:John Wiley&Sons, Inc.    

年代:1994

数据来源: WILEY