Xiaolin Yuan

As an indispensable piece of production equipment in the industrial field, wire rope is directly related to personnel safety and the normal operation of equipment. Therefore, it is necessary to perform broken wire detection. Deep learning has powerful feature-learning capabilities and is characterized by high accuracy and efficiency, and the YOLOv8 object detection model has been adopted to detect wire breaks in electromagnetic signal images of wire rope, achieving better results. Nevertheless, the black box problem of the model brings a new trust challenge, and it is difficult to determine the correctness of the model’s decision and whether it has any potential problems, so an interpretability study needed to be carried out. In this work, a perturbation-based interpretability method—ESTC (Eliminating Splicing and Truncation Compensation)—is proposed, which distinguishes itself from other methods of the same type by targeting the signaling object instead of the ordinary object. ESTC is compared with other model-agnostic interpretable methods, LIME, RISE, and D-RISE, using the same model on the same test set. The results indicate that our proposed method is objectively superior to the others, and the interpretability analysis shows that the model predicts in a way that is consistent with the priori knowledge of the manual rope inspection. This not only increases the credibility of using the object detection model for broken wire detection but also has important implications for the practical application of using object detection model to detect wire breaks.

The molecular pump fault results in a vacuum leak that can lead to accidents in a fusion device. The fault detection for the molecular pump can provide an early warning to avoid a greater loss in a fusion device. This paper proposes a Support Vector Machine (SVM) framework for fault detection in a molecular pump. This study investigates the key technologies, framework, and system development methods of the data-driven fault detection system for a molecular pump. This study proposes a molecular pump test system to simulate the fault of a molecular pump to solve the highly unbalanced data problem and verify the framework availability. The packaged development framework, implemented in the test system, realizes the fault detection function. The developed system offers better practicability and can effectively detect perform faults in a molecular pump. The results obtained would support new ideas and methods for early warning in molecular pumps and pave the way for stable and reliable vacuum pump systems in a fusion device. Graphical Abstract

We report on design and technology improvements for a flowing liquid lithium (FLiLi) limiter inserted into auxiliary heated discharges in the experimental advanced superconducting tokamak device. In order to enhance Li coverage uniformity and erosion resistance, a new liquid Li distributor with homogenous channels was implemented. In addition, two independent electromagnetic pumps and a new horizontal capillary structure contributed to an improvement in the observed Li flow uniformity (from 30% in the previous FLiLi design to >80% in this FLiLi design). To improve limiter surface erosion resistance, hot isostatic press technology was applied, which improved the thermal contact between thin stainless steel protective layers covering the Cu heat sink. The thickness of the stainless steel layer was increased from 0.1 mm to 0.5 mm, which also helped macroscopic erosion resilience. Despite the high auxiliary heating power up to 4.5 MW, no Li bursts were recorded from FLiLi, underscoring the improved performance of this new design.

Organic triplet photosensitizers (R-1 and R-2) enhanced with the resonance energy transfer (RET) effect were prepared. Rhodamine was used as an intramolecular energy donor, and iodo-styryl-Bodipy was used as intramolecular energy acceptor/spin converter. Both the energy donor and energy acceptor in R-1 and R-2 give strong absorption in the visible region but at different wavelengths (e.g. for R-1, ε = 120 000 M⁻¹ cm⁻¹ at 557 nm for the energy donor and ε = 73 300 M⁻¹ cm⁻¹ at 639 nm for the energy acceptor). As a result, the photosensitizers show broadband absorption in the visible spectral region. In comparison, conventional triplet photosensitizers contain only one visible light-harvesting chromophore; thus, there is usually only one major absorption band in the visible spectral region. Using steady state and time-resolved spectroscopy, we demonstrated that photoexcitation in the energy donor was followed by intramolecular singlet energy transfer, and then via intersystem crossing (ISC) of the energy acceptor (spin converter), triplet excited states localized on the iodo-styryl-Bodipy were produced, which was confirmed by nanosecond time-resolved transient difference absorption spectroscopy. The organic dyad triplet photosensitizers were used for photoredox catalytic organic reactions to prepare pyrrolo[2,1-a]isoquinoline, and we found that the photocatalytic capability was improved with the RET effect. The dyads were also used as fluorescent stains for LLC cancer cells. Photodynamic effect was observed with the same cells, which were killed on photoirradiation with 635 nm red-emitting LED after incubation with the triplet photosensitizers. Therefore, these photosensitizers can be potentially developed as dual functional theranostic reagents. Using the molecular structural protocol reported herein, organic triplet photosensitizers with strong broadband absorption in the visible spectral region and predictable ISC can be easily designed. These results are useful for the study of organic triplet photosensitizers in the area of organic photochemistry/photophysics, photoredox catalytic organic reactions and photodynamic therapy (PDT).