NMR propagator measurements on flow through a random pack of porous glass beads and how they are affected by dispersion, relaxation, and internal field inhomogeneities.
NMR propagator measurements on flow through a random pack of porous glass beads and how they are affected by dispersion, relaxation, and internal field inhomogeneities.
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NMR 传播器测量流过随机排列的多孔玻璃珠的流量，以及它们如何受到色散、松弛和内部场不均匀性的影响。
DOI：
10.1103/physreve.69.021201
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
D. Cory
中科院分区：
文献类型：
--
作者：
U. Scheven;J. Seland;D. Cory
我们让水流过一堆多孔玻璃珠，并采用核磁共振来测量斯托克斯流型中的分子位移分布-传播因子。流体流过几个演化时间，以达到固定的平均位移，并分析所得到的传播子的时间依赖性的扩散，NMR弛豫，和信号损失的影响，由于内部字段。我们描绘和说明的实验制度，这些不同的影响，使他们的存在感到。一个简单的模型系统上的模拟再现了我们的实验结果的基本特征，并提供了深入了解的机制塑造的传播。
We flow water through a pack of porous glass beads and employ NMR to measure molecular displacement distributions--the propagators--in the Stokes flow regime. Fluid is flowed over several evolution times to attain fixed mean displacements, and the time dependence of the resulting propagators is analyzed for the effects of diffusion, NMR relaxation, and signal loss due to internal fields. We delineate and illustrate the experimental regimes in which these different effects make their presence felt. Simulations on a simple model system reproduce the essential features of our experimental results and provide insight into the mechanisms shaping the propagators.