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In recent years, thermal imaging cameras are widely used in the field of intelligent surveillance because of their special imaging characteristics and better privacy protection properties. However, due to the low resolution and fixed location for current thermal imaging cameras, it is difficult to effectively identify human behavior using a single detection method based on skeletal keypoints. Therefore, a self-update learning method is proposed for fixed thermal imaging camera scenes, called the behavioral parameter field (BPF). This method can express the regularity of human behavior patterns concisely and directly. Firstly, the detection accuracy of small targets under low-resolution video is improved by optimizing the YOLOv4 network to obtain a human detection model under thermal imaging video. Secondly, the BPF model is designed to learn the human normal behavior features at each position. Finally, based on the learned BPF model, we propose to use metric modules, such as cosine similarity and intersection over union matching, to accomplish the classification of human abnormal behaviors. In the experimental stage, the living scene of the indoor elderly living alone is applied as our experimental case, and a variety of detection models are compared to the proposed method for verifying the effectiveness and practicability of the proposed behavioral parameter field in the self-collected thermal imaging dataset for the indoor elderly living alone. [ABSTRACT FROM AUTHOR]

Zeolites with encapsulated transition metal species are extensively applied in the chemical industry as heterogenous catalysts for favorable kinetic pathways. To elucidate the energetic insights into formation of subnano‐sized molybdenum trioxide (MoO3) encapsulated/confined in zeolite Y (FAU) from constituent oxides, we performed a systematic experimental thermodynamic study using high‐temperature oxide melt solution calorimetry as the major tool. Specifically, the formation enthalpy of each MoO3/FAU is less endothermic than corresponding zeolite Y, suggesting enhanced thermodynamic stability. As Si/Al ratio increases, the enthalpies of formation of MoO3/FAU with identical loading (5 Mo‐wt%) tend to be less endothermic, ranging from 61.1 ± 1.8 (Si/Al = 2.9) to 32.8 ± 1.4 kJ/mol TO2 (Si/Al = 45.6). Coupled with spectroscopic, structural and morphological characterizations, we revealed intricate energetics of MoO3–zeolite Y guest–host interactions determined by the Si/Al ratio and the subtle redox and/or local structural evolutions of encapsulated MoO3. [ABSTRACT FROM AUTHOR]

BACKGROUND: The non-fusion system of lumbar interspinous process distraction device provides a new treatment option for lumbar degenerative diseases. However, at present, the clinical application and research of lumbar interspinous process distraction device are reported insufficiently in China, especially for the domestic lumbar interspinous process distraction device. OBJECTIVE: To verify the scientific nature and effectiveness of the new domestic lumbar interspinous process distraction device through finite element analysis and in vitro biomechanical experiment of goat lumbar spine. METHODS: (1) Finite element analysis of new domestic lumbar interspinous process distraction device: L2-L5 three-dimensional model of vertebral body was established based on normal adult lumbar CT data. From then on, new domestic lumbar interspinous process distraction device model, new lumbar interspinous process distraction device model of lumbar non fusion system were successively built. The mechanical conditions were given under the physiological conditions of lumbar spine. Biomechanical analysis was carried out before and after the new domestic lumbar interspinous process distraction device was implanted. (2) In vitro biomechanical analysis of new domestic lumbar interspinous process distraction device: the lumbar vertebrae (L1-L5) of 24 adult male goats were obtained, and the new domestic lumbar interspinous process distraction device was implanted between the L3-4 spinous process. Before and after the placement of the lumbar interspinous process distraction device, the lumbar motion range and the pressure of the intervertebral disc under the flexion, extension, lateral bending and rotation of the lumbar specimens were detected. RESULTS AND CONCLUSION: (1) After the new lumbar interspinous process distraction device was implanted, the motion range and the pressure of the intervertebral disc of responsible segment were reduced, while the adjacent segments' mobility and the pressure of the intervertebral disc were almost unaffected. It was theoretically verified that the new domestic lumbar interspinous process distraction device could provide the biomechanical basis for the treatment of the lumbar degenerative diseases, and contribute to the theoretical reference for the prevention of the clinical diseases. (2) In the state of extension, the motion range of L3-4 vertebral body after implanting the new lumbar interspinous process distraction device was significantly lower than that before implantation (P < 0.05). There was no significant difference between L2-3 and L4-5 vertebral body after implanting the new lumbar interspinous process distraction device and that before implantation (P > 0.05). In the state of flexion, lateral bending and rotation, there was no significant difference between L2-3, L3-4 and L4-5 vertebral body after implanting the lumbar interspinous process distraction device and that before implantation (P > 0.05). In the state of extension, the pressure of intervertebral disc after L3-4 vertebral body implantation was significantly lower than that before implantation (P < 0.05). There was no significant difference between L2-3 and L4-5 vertebral body implantation and that before implantation (P > 0.05). In the state of flexion, lateral bending and rotation, there was no significant difference between L2-3, L3-4 and L4-5 vertebral body implantation and that before implantation (P > 0.05). (3) The results showed that the scientific nature and validity of the new domestic lumbar interspinous process distraction device was verified by three-dimensional finite element analysis and in vitro animal lumbar specimens experiment, which provided a strong basis for the animal experiment, clinical experiment, clinical application and clinical production of the new domestic lumbar interspinous process distraction device. [ABSTRACT FROM AUTHOR]

Three comprehensive surveys were performed in the Changjiang (Yangtze River) Estuary (CJE) to understand the biogenic silica (BSi) composition, behavior and budget. It is indicated that the BSi is composed of phytoliths, phytoplankton and sponges; phytolith BSi has 16 forms and account for 23% to 83% of the bulk BSi in the maximum turbidity zone. The budget shows that the major exogenous BSi source in the water column of the CJE is the riverine input, accounting for 95% of the total BSi input. Dominant processes that maintain BSi levels in the water column are the primary production (55 Gmol/a) and the subsequent BSi sedimentation (46 Gmol/a); and the BSi pool produced by the primary production represents two point three times the BSi loading of the Changjiang River and 63% of the BSi output, respectively. The net export (26 Gmol/a) of BSi from the CJE to the East China Sea and Yellow Sea roughly equals the riverine BSi loading. The observed total accumulation of BSi is one point seven times larger than the loading of total BSi output, with 53% to 88% of phytolith BSi and their assemblage, indicating that there has already been a 'filter' of terrestrial BSi. The reverse weathering in sediments is an important process for the reactive silica removal in the CJE due to authigenic alterations. It is indicated that the phytolith fluxes in the suspended load represent a significant BSi source in the estuary, and the CJE would act as a net BSi sink. [ABSTRACT FROM AUTHOR]