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Object detection algorithms play a crucial role in other vision tasks. This paper finds that the action recognition algorithm SlowFast's detection algorithm FasterRCNN (Region Convolutional Neural Network) has disadvantages in terms of both detection accuracy and speed and the traditional IOU (Intersection over Union) localization loss is difficult to make the detection model converge to the minimum stability point. To solve the above problems, the article uses YOLOv3 (You Only Look Once), YOLOX, and CascadeRCNN to improve the detection accuracy and speed of the SlowFast. This paper proposes a new localization loss function that adopts the Lance and Williams distance as a new penalty term. The new loss function is more sensitive when the distance difference is smaller, and this property is very suitable for the late convergence of the detection model. The experiments were conducted on the VOC (Visual Object Classes) dataset and the COCO dataset. In the final videos test, YOLOv3 improved the detection speed by 10.5 s. CascadeRCNN improved by 3.1%AP compared to FasterRCNN in the COCO dataset. YOLOX's performance on the COCO dataset is also mostly better than that of FasterRCNN. The new LIOU (Lance and Williams Distance Intersection over Union) localization loss function performs better than other loss functions in the VOC dataset. It can be seen that improving the detection algorithm of the SlowFast seems to be crucial and the proposed loss function is indeed effective. [ABSTRACT FROM AUTHOR]

The stereocomplex crystal (SC) in poly(l‐lactide)/poly(d‐lactide) (PLLA/PDLA) blends provide great opportunities to enhance the performance of PLA materials. Unfortunately, obtaining the SC in high‐molecular‐weight (PLLA/PDLA) blends is still a challenge. In this study, halloysite nanotubes (HNTs) are used to induce the crystallization of SC in PLA with a high molecular weight. By investigating the non‐isothermal and isothermal crystallization behaviors of PLLA/PDLA/HNTs, it is demonstrated that HNTs promote SC growth over homocrystal (HC). According to the investigations of crystallization morphologies and molecular interactions, it is deduced that weak interactions between HNTs and PLA induced the accumulation of PLLA and PDLA, and the high lattice matching promoted the growth of SC. This would encourage the usage of SC crystals in PLA samples in the industry. [ABSTRACT FROM AUTHOR]