The novel working principle enables spiking cameras to capture high-speed moving objects. However, the applications of spiking cameras can be affected by many factors, such as brightness intensity, detectable distance, and the maximum speed of moving targets. Improper settings such as weak ambient brightness and too short object-camera distance, will lead to failure in the application of such cameras. To address the issue, this paper proposes a modeling algorithm that studies the detection capability of spiking cameras. The algorithm deduces the maximum detectable speed of spiking cameras corresponding to different scenario settings (e.g., brightness intensity, camera lens, and object-camera distance) based on the basic technical parameters of cameras (e.g., pixel size, spatial and temporal resolution). Thereby, the proper camera settings for various applications can be determined. Extensive experiments verify the effectiveness of the modeling algorithm. To our best knowledge, it is the first work to investigate the detection capability of spiking cameras.
Archaea are important participants in biogeochemical cycles of metal(loid)-polluted ecosystems, whereas archaeal structure and function in response to metal(loid) contamination remain poorly understood. Here, the effects of multiple metal(loid) pollution on the structure and function of archaeal communities were investigated in three zones within an abandoned sewage reservoir. We found that the high-contamination zone (Zone I) had higher archaeal diversity but a lower habitat niche breadth, relative to the mid-contamination zone (Zone II) and low-contamination zone (Zone III). Particularly, metal-resistant species represented by potential methanogens were markedly enriched in Zone I (cumulative relative abundance: 32.24%) compared to Zone II (1.93%) and Zone III (0.10%), and closer inter-taxon connections and higher network complexity (based on node number, edge number, and degree) were also observed compared to other zones. Meanwhile, the higher abundances of potential metal-resistant and methanogenic functions in Zone I (0.24% and 9.24%, respectively) than in Zone II (0.08% and 7.52%) and Zone III (0.01% and 1.03%) suggested archaeal functional adaptation to complex metal (loid) contamination. More importantly, six bioavailable metal(loid)s (titanium, tin, nickel, chromium, cobalt, and zinc) were the main contributors to archaeal community variations, and metal(loid) pollution reinforced the role of deterministic processes, particularly homogeneous selection, in the archaeal community assembly.
The photochemical behavior of a model PAH, naphthalene, was investigated under simulated sunlight irradiation with different dissolved organic matter (DOM) in seawater. The results revealed that naphthalene was prone to direct photolysis (Φd = 1.34 × 10-3) and could be degraded by 3DOM*/1O2-induced reactions with fulvic acid (FA) and humic acid (HA) at low concentrations. However, the DOM at a high level dramatically decreased the kobs due to the higher light attenuation and radical competition effect. The presence of FA resulted in lower 3DOM*/1O2 generation and quantum yield compared with HA, but it achieved higher degradation kinetics due to the higher reactivity between 3FA* and naphthalene and their lower binding effect. The naphthalene degradation in natural water with different depths and DOM were modeled based on the experimental results, which revealed the important role of indirect photolysis initiated by inorganic constituents. Moreover, several degradation intermediates were identified by GC-MS and three possible pathways were proposed. The Quantitative Structure Activity Relationships (QSAR) evaluation revealed that some intermediates are more toxic than original naphthalene. This study offers further insights into the photochemical behavior of PAHs, which will facilitate our understanding of the persistence and ecological risks of organic contaminants in natural waters.
The solid carbon source (poly-3-hydroxybutyrate co 3 hyroxyvalerate, PHBV) and manganese oxide mineral (Mn ore) were proposed firstly as co-substrates for eliminating nutrients and sulfamethoxazole (SMX) in this study. Results showed that high-rate nitrate and phosphate removal could be achieved in PHBV/Mn ore systems with the average efficiencies of 90% and 66.7%, respectively, although the addition of SMX decreased denitrification performance by 4.5-10.5%. SMX was removed mainly via biodegradation of enriched denitrifying microbes, with the average removal efficiency of 20-50% in PHBV/Mn ore systems, which was higher than that in PHBV systems. The existence of Mn ore markedly shaped the microbial community structure, leading to the dominant bacteria transforming from Microscillaceae to Sporomusaceae. The genera of Geobactor, Desulfovibrio and Anaerovorax were found to maintain the stability of microbial system as keystone species. Surprisingly, large amount of Mn(II) was accumulated, which not only verify the involvement of Mn cycling in decontamination process, but also might explain the propagation of ARGs (tnpA-04 and tnpA-05) in host microorganisms. Therefore, the optimized mixture proportion of PHBV and Mn ore should be further estimated avoiding Mn (II) accumulation in the effluent. On the whole, these results might shed light on new insight for advanced treatment of nutrients and emerging pollutants in biofilm reactors.