Acoustic tracking of whales’ underwater cruises is essential for protecting marine ecosystems. For cetacean conservationists, fewer hydrophones will provide more convenience in capturing high-mobility whale positions. Currently, it has been possible to use two hydrophones individually to accomplish direction finding or ranging. However, traditional methods only aim at estimating one of the spatial parameters and are susceptible to the detrimental effects of reverberation superimposition. To achieve complete whale tracking under reverberant interference, in this study, an intelligent acoustic tracking model (CIAT) is proposed, which allows both horizontal direction discrimination and distance/depth perception by mining unpredictable features of position information directly from the received signals of two hydrophones. Specifically, the horizontal direction is discriminated by an enhanced cross-spectral analysis to make full use of the exact frequency of received signals and eliminate the interference of non-source signals, and the distance/depth direction combines convolutional neural network (CNN) with transfer learning to address the adverse effects caused by unavoidable acoustic reflections and reverberation superposition. Experiments with real recordings show that 0.13 km/MAE is achieved within 8 km. Our work not only provides satisfactory prediction performance, but also effectively avoids the reverberation effect of long-distance signal propagation, opening up a new avenue for underwater target tracking.
The effects of lophatherum gracile brongn flavonoids on the multiscale structure and functional properties of wheat dough were investigated. Wheat dough samples with varying contents of lophatherum gracile brongn flavonoids were analyzed to assess changes in thermal-mechanical rheological properties, microstructure, chemical interactions, water distribution, and macropolymer formation by Mixolab mixer, fluorescence microscopy, and low-field nuclear magnetic resonance (LF-NMR). The findings revealed that lophatherum gracile brongn flavonoids disrupted the three-dimensional network of gluten proteins in the wheat dough, leading to decreased water-binding capacity and reduced gluten protein crosslinking while enhancing thermal stability and inhibiting the starch retrogradation of the dough. This study provided important insights into the interaction mechanisms between lophatherum gracile brongn flavonoids and the proteins/starch in wheat dough, offering theoretical guidance for the development of novel wheat-based products for industrialization and practical production.
This study aimed to investigate the effects of cold storage time and matcha addition on the multi-scale structure and functionality of gluten protein and starch in re-steamed bread. Results showed that prolonged cold storage destroyed the integrity of gluten networks by breaking disulfide bonds and altering protein secondary structures, accompanied by moisture loss and migration; meanwhile, starch retrogradation was significantly promoted, resulting in increased hardness and decreased specific volume. The addition of 0.5–1.0% of matcha stabilized disulfide bonds and inhibited starch retrogradation, thus alleviating quality decline. When the addition amount exceeded 1.0%, high concentrations of polyphenols depolymerized gluten proteins and accelerated moisture transfer, causing a further drop in specific volume. Pearson correlation analysis verified the close correlations between macroscopic quality and microstructural characteristics. This study explored the mechanisms underlying the effects of cold storage time and matcha addition on the quality of re-steamed bread, providing a systematic scientific basis for the application of tea flour products in cold storage.