PRACTICAL REGULARIZATION METHODS FOR ANALYSIS OF EXAFS SPECTRA: DATA ANALYSIS

X射线吸收精细结构XAFS是一项强大的研究技术 探索生物中金属原子的局域环境 大分子。这些金属原子普遍存在于 例如，酶对它们的功能是必不可少的。分析 XAFS数据管理是一项耗时的活动，需要广泛的 经验，以正确地做，限制了 技术。为了改善这种情况，我们已经申请了 求解反问题的Tikhonov正则化方法 直接重建原子分布，而不是 诉诸于对其形状的临时假设。该程序具有 在测试用例中表现出色，解决了 通常无法解析，并且由于该方法是线性的，因此没有 局部极小值的困难。正则化过程可以是 在普通台式计算机上只需几分钟即可完成，我们已经 满意地重建了几个原子的分布 同时打字。在测试用例中，我们已经找到了该方法 其表现优于传统方法。我们目前正在努力 将此方法推广到多次散射。这部作品代表了 朝向可预期的直接方法的有希望的发展 以便在未来的研究中得出更可靠的结果和解释。

X-ray absorption fine structure XAFS is a powerful technique for probing the local environment of metal atoms in biological macromolecules. These metal atoms are common in the active sites of enzymes, for example, and are essential for their function. Analysis of XAFS data is a time consuming activity that requires extensive experience to do correctly, limiting the range of applicability of the technique. In an attempt to improve this situation, we have applied the approach of Tikhonov regularization to solve the inverse problem of reconstructing the distribution of atoms directly, without resorting to ad-hoc assumptions about its shape. The procedure has performed excellently in test cases, resolving features that are normally unresolvable, and since the method is linear, there is no difficulty with local minima. The regularization procedure can be done on ordinary desktop computers in minutes, and we have satisfactorily reconstructed the distributions for several atomic types simultaneously. In test cases we have found the method far outperforms traditional approaches. We are presently working to generalize this method for multiple scattering. This work represents a promising development towards direct methods which can be expected to yield more reliable results and interpretations in future studies.