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Water is a vital resource essential to the survival and development of all creatures. With the rapid growth of industry and agriculture, people face a severe threat of ecological destruction and environmental pollution while living earthly lives. Water pollution, in particular, harms people’s health the most. As a result, water supply security has become a top priority. As a critical point in water supply safety, monitoring water quality effectively and forecasting sudden water contamination on time has become a research hotspot worldwide. With the rapid development and wide applications of artificial intelligence and computer vision technologies, biological activity identification-based intelligent water quality monitoring methods have drawn widespread attention. They were taking fish activities as the water-quality indicator has gained extensive attention by introducing advanced computer vision and artificial intelligence technologies with low cost and ease of carrying. This article comprehensively reviews recent progress in the research and applications of machine vision-based intelligent water quality monitoring and early warning techniques based on fish activity behavior recognition. In detail, it addresses water quality-oriented fish detection and tracking, activity recognition, and abnormal behavior recognition-based intelligent water quality monitoring. It analyzes and compares the performance and their favorite application conditions. Finally, it summarizes and discusses the difficulties and hotspots of water quality monitoring based on the fish’s abnormal behavior recognition and their future development trends.

For evaluating the economy and feasibility about blast fragmentation warhead striking aircraft in aircraft shelter, taking a typical aircraft and single/double aircraft shelter as study objects, based on the thought of simple/quadratic surface fitting, the 3D surface models of aircraft and shelter are built. According to the velocity and position model of fragment, combined with the transformation relationship of coordinate system, the missile-target encounter algorithm is given. The ruin tree model of aircraft is constructed to calculate the ruin probability algorithm of aircraft. For reducing the computation of missile-target encounter, a mean ruin probability algorithm of aircraft based on integration method is proposed, which slices target area to grids and takes grids as alternative aim point. Taking maximum to entire ruin effect of all aircrafts as target, the optimizing algorithm to strike scheme about minimum missile consumption and find best aim point based on advanced PSO algorithm are proposed. The striking scheme optimizing about fragmentation warhead striking aircraft in single/double aircraft shelter is simulated. The result shows that, low blast height, small CEP, combination strike strategy with multiply aim points can reduce the minimum missile consumption effectively.

The Hangenberg Crisis coincided with a large decline of biodiversity and widespread anoxia in the end‐Devonian ocean. Previous research attributed marine anoxia to the spread of deeply‐rooted plants and/or increased volcanism on the continents, but crucial links have not been thoroughly explored. Herein, we propose enhanced weathering as a key trigger, as evidenced by a negative shift (∼8‰) in lithium isotopes and a coupled response in carbon isotopes of marine carbonates in South China. Our findings imply that rapid weathering of crustal rocks increased nutrient delivery to the ocean, as indicated by an increase in the carbonate‐associated phosphate levels, contributing to oceanic eutrophication. In the absence of massive volcanic emissions and intense orogeny, the cause of enhanced continental weathering was likely the expansion of the terrestrial rhizosphere, highlighting the potential for land plant evolution to initiate weathering changes of sufficient severity to trigger a major bio/environmental crisis in the Earth system. Plain Language Summary: The colonization of land plants during the Devonian is believed to have played a key role in regulating Earth's climate. The initially rapid expansion of seed plants into unvegetated or sparsely vegetated uplands is considered to have caused enhanced rock dissolution relative to clay formation on end‐Devonian continents. As a consequence, larger amounts of isotopically‐light lithium were transported to the ocean via rivers, resulting in a distinct negative excursion in seawater lithium isotopes. Concurrently, increased riverine nutrient delivery stimulated marine primary production and thus facilitated the expansion of oceanic anoxia. As a result, drawdown of atmospheric CO2 resulted in climatic cooling, which together with widespread seafloor anoxia, triggered the major biotic turnover known as the "Hangenberg Crisis". Key Points: Negative shift in carbonate lithium isotopes records major enhancement of continental weathering during the end‐DevonianEnhanced chemical weathering increased riverine nutrient delivery and contributed to widespread marine anoxia and the Hangenberg CrisisRapid expansion of seed plants in sparsely vegetated uplands may account for weathering‐driven climatic cooling and oceanic changes [ABSTRACT FROM AUTHOR]

It is necessary to use the least square algorithm to establish the mapping relationship between the charge-coupled device (CCD) image coordinate system and the celestial tangent plane coordinate system when using the digital zenith camera for astronomical positioning. The least squares algorithm only considers the errors in the observation, but does not consider the errors in the coefficient matrix and the possible gross errors in the data. In order to improve the accuracy of the digital zenith camera in astronomical positioning, the least squares algorithm and the total least squares algorithm are effectively combined to form a mixed least squares algorithm, which can take into account the errors of the coefficient matrix and observation in coordinate transformation. In order to eliminate the influence of the possible gross errors in star recognition data on astronomical solution, the proposed algorithm is weighted robustly, and a reasonable weight matrix is set combined with magnitude. The results of data analysis show that the robust weighted mixed least squares algorithm has high accuracy in astronomical solution. [ABSTRACT FROM AUTHOR]