A reliable quantitative analysis in electron tomography, which depends on the segmentation of the three-dimensional reconstruction, is challenging because of constraints during tilt-series acquisition (missing wedge) and reconstruction artifacts introduced by reconstruction algorithms such as the Simultaneous Iterative Reconstruction Technique (SIRT) and Discrete Algebraic Reconstruction Technique (DART). We have carefully evaluated the fidelity of segmented reconstructions analyzing a disordered mesoporous carbon used as support in catalysis. Using experimental scanning transmission electron microscopy (STEM) tomography data as well as realistic phantoms, we have quantitatively analyzed the effect on the morphological description as well as on diffusion properties (based on a random-walk particle-tracking simulation) to understand the role of porosity in catalysis. The morphological description of the pore structure can be obtained reliably both using SIRT and DART reconstructions even in the presence of a limited missing wedge. However, the measured pore volume is sensitive to the threshold settings, which are difficult to define globally for SIRT reconstructions. This leads to noticeable variations of the diffusion coefficients in the case of SIRT reconstructions, whereas DART reconstructions resulted in more reliable data. In addition, the anisotropy of the determined diffusion properties was evaluated, which was significant in the presence of a limited missing wedge for SIRT and strongly reduced for DART.

中文翻译：

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从高保真3D重建量化中孔碳的形态和扩散特性。

电子断层扫描的可靠定量分析依赖于三维重建的分割，因此具有挑战性，因为倾斜系列采集（缺少楔形）期间存在约束，并且重建算法（如同时迭代重建技术（SIRT）引入了重建伪影）和离散代数重构技术（DART）。我们已经仔细分析了分段重构的保真度，分析了无序介孔碳在催化中的支持作用。使用实验性扫描透射电子显微镜（STEM）断层扫描数据以及真实的体模，我们已经定量分析了对形态描述和扩散特性的影响（基于随机游走的粒子跟踪模拟），以了解孔隙度在催化中的作用。即使存在有限的缺失楔形，也可以使用SIRT和DART重建可靠地获得孔结构的形态学描述。但是，测得的孔体积对阈值设置敏感，很难为SIRT重建全局定义。在SIRT重建的情况下，这会导致扩散系数的明显变化，而DART重建会产生更可靠的数据。另外，评估了确定的扩散特性的各向异性，