Diffusivity anisotropy in a rhyolite and its relation to pore structure
Diffusivity anisotropy in a rhyolite and its relation to pore structure
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流纹岩中的扩散率各向异性及其与孔隙结构的关系
DOI：
10.1016/j.enggeo.2005.07.002
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发表时间：
2005
影响因子：
7.4
通讯作者：
S. Nakashima
中科院分区：
文献类型：
--
作者：
T. Yokoyama;S. Nakashima
通过对具有各向异性孔隙结构的流纹岩进行穿透扩散实验，定量评价了离子在岩石孔隙水中的扩散系数各向异性。流纹岩具有平面流动结构，具有相对于流动方向（X-Y平面）的细长孔隙形状。垂直于该流动结构的方向（Z方向）的K+离子扩散系数比正交平行方向（X和Y方向）的K+离子扩散系数小约5-9倍。对背散射电子显微镜图像的孔几何分析表明，X-、Y-和Z-方向之间的孔长度比大致为2：2：1。Z方向的较短孔长度似乎降低了孔连通性，导致该方向的较大弯曲度和较小扩散率。这种扩散率的各向异性需要考虑到扩散限制的地质过程，如污染物的传输和岩石变形的精确建模。
The diffusivity anisotropy of ions through rock pore water was evaluated quantitatively by through-diffusion experiments on a rhyolite rock having anisotropic pore structure. The rhyolite has planar flow structure with elongated pore shapes to the flow direction (X–Y plane). Diffusion coefficients of K+ions for the direction perpendicular to this flow structure (Z-direction) were about 5–9 times smaller than those for the orthogonal parallel directions (X- and Y-direction). Pore geometrical analyses on backscattered electron microscopic images indicated that the pore length ratios among the X-, Y-, and Z-direction were roughly 2:2:1. This shorter pore length for the Z-direction appears to reduce pore connectivity, causing larger tortuosity and smaller diffusivity for this direction. This diffusivity anisotropy needs to be taken into account for precise modeling of diffusion-limited geological processes such as contaminant transport and rock deformation.
影响因子：
2.9
作者：
S. Nakashima
通讯作者：
S. Nakashima