PULSED-GRADIENT SPIN-ECHO NMR FOR PLANAR, CYLINDRICAL, AND SPHERICAL PORES UNDER CONDITIONS OF WALL RELAXATION
PULSED-GRADIENT SPIN-ECHO NMR FOR PLANAR, CYLINDRICAL, AND SPHERICAL PORES UNDER CONDITIONS OF WALL RELAXATION
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DOI：
10.1006/jmra.1995.1055
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发表时间：
1995-03-01
期刊：
影响因子：
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通讯作者：
CALLAGHAN, PT
中科院分区：
文献类型：
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作者：
CALLAGHAN, PT
脉冲梯度自旋回波核磁共振的理论在分子被困在孔内的情况下，已扩展到包括壁弛豫效应。表达式得到的窄梯度脉冲条件下的矩形，圆柱形和球形孔隙的回波衰减。圆柱形的结果是新的，而那些矩形和球形孔不同于以前公布的公式。目前的结果在一些特殊的限制进行了验证。它表明，“衍射”的影响仍然强烈明显时，壁松弛考虑。此外，如果梯度脉冲之间的时间超过a（2）/D（其中D是分子自扩散系数），则从回波最小值的位置获得的孔半径a的偏差在实践中是弱的。(C)出版社：Academic Press
The theory of pulsed-gradient spin-echo NMR in the case of molecules trapped within pores has been extended to include wall-relaxation effects. Expressions are obtained for the echo attenuation under the narrow-gradient-pulse condition for rectangular, cylindrical, and spherical pores. The cylindrical result is new, while those for rectangular and spherical pores differ from previously published formulas. The present results are verified in a number of special limits. It is shown that ''diffraction'' effects are still strongly apparent when wall relaxation is taken into account. Furthermore, deviations in the pore radius, a, obtained from the position of the echo minimum, are weak in practice, provided that the time between the gradient pulses exceeds a(2)/D, where D is the molecular self-diffusion coefficient. (C) 1995 Academic Press, Inc.