1532条X射线散射光谱评估回收石膏痕量石棉检测 所选模型准确率0.9450 可检出监管阈值五分之一的样本
《科学报告》11月14日发表一项回收石膏检测研究。建筑拆除废料中的石棉污染阻碍石膏回收，而约0.1重量百分比的监管阈值远低于常规检测手段容易稳定识别的水平。
研究团队用广角 X 射线散射评估机器学习对回收石膏中痕量温石棉的检测，温石棉含量范围为0.001至9重量百分比。团队在同一个 Extra-Trees 估计器下比较六种特征表示，使用来自373个样本的1532条光谱，采用分组感知的数据划分和18个随机种子。
在内部测试中，六种表示之间无法区分高下，团队因此报告最小可检出差异为0.030至0.062，而不给出排名。未变换的原始光谱是内部最强检测器，AUC 为0.9993±0.0007，在假阳性率9.4%时假阴性为零；但它漏检了一块未进入训练的商用纤维水泥板的全部16次测量，而一种无监督线性投影全部检出。
团队最终按跨基质迁移能力选定模型：仅使用温石棉诊断反射的主成分分析模型准确率为0.9450。一个独立测定含量为0.0201重量百分比、仅为监管阈值五分之一、且未参与任何选模步骤的留存生产样本，被正确识别为含石棉。作者同时指出，定量仍属半定量，对数平均绝对误差为0.62，且不能跨基质迁移，该框架适合工业回收中的在线筛查。论文由 Wilhelm、Lotter、Scherdel 等作者发表。
Machine Learning on 1,532 X-Ray Spectra Detects Trace Asbestos in Recycled Gypsum, Selected Model Accuracy 0.9450
Scientific Reports on November 14 published a study on detecting asbestos in recycled gypsum. Asbestos contamination blocks gypsum recycling from demolition waste, and regulatory thresholds near 0.1 wt% lie well below what routine methods identify reliably.
The team evaluated machine-learning detection of trace chrysotile (0.001 to 9 wt%) in recycled gypsum from wide-angle X-ray scattering, comparing six feature representations under one Extra-Trees estimator on 1,532 spectra from 373 samples, with group-aware splits and 18 seeds.
Internally the representations were indistinguishable, so the authors report the minimum detectable difference (0.030 to 0.062) rather than a ranking. The untransformed spectrum was the strongest internal detector (AUC 0.9993 ± 0.0007, zero false negatives at 9.4% false positives), yet it missed all 16 measurements of a commercial fibre-cement board absent from training, which an unsupervised linear projection detected in full.
The team therefore selected on cross-matrix transfer, reporting a PCA model restricted to the diagnostic chrysotile reflections with accuracy 0.9450. A retained production sample independently assayed at 0.0201 wt%, one fifth of the regulatory threshold and used in no selection step, was identified as asbestos-bearing. Quantification remains semi-quantitative (log-MAE 0.62) and does not transfer across matrices, so the authors conclude the framework suits on-line screening in industrial recycling. The paper is by Wilhelm, Lotter, Scherdel and colleagues.
来源：《科学报告》
发布：GSM·美国（发布链接）
图片来源：图：用于 X 射线粉末衍射测量的德拜-谢乐相机（资料图），藏于海德堡大学地球科学研究所博物馆。来源：Armin Kübelbeck，Wikimedia Commons，CC BY-SA 3.0。 / Photo: A Debye-Scherrer camera for X-ray powder diffractometry (file photo), held by the museum of the Institute of Earth Sciences at Heidelberg University. Source: Armin Kübelbeck, Wikimedia Commons, CC BY-SA 3.0.
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