A Pilot Study on the Diel Vertical Migration Pattern of Mesopelagic Fishes in the Southern and Central South China Sea

The diel vertical migration of mesopelagic fishes in the southern (S-May station and S-Nov station) and central (C-Jun station and C-Dec station) South China Sea was investigated through a series of continuous field surveys conducted in May, June, November, and December 2017. These surveys employed a combination of mid-water trawl and acoustics techniques. The diel migration process, vertical distribution, acoustic migration proportion, and migration pattern of mesopelagic fishes were analyzed. The results revealed that mesopelagic fishes initiated an upward migration before sunset, with the process concluding within 30–120 min after dark. Subsequently, they commenced a downward migration before dawn, which terminated within 10–50 min after sunrise. The mesopelagic deep-sea layers of mesopelagic fishes at the S-May, S-Nov, C-Jun, and C-Dec stations ranged from 360 to 700 m, 350 to 680 m, 350 to 520 m, and 300 to 700 m, respectively. The acoustic migration proportions of mesopelagic fishes at the corresponding stations were found to be approximately 44.5%, 25.7%, 29.8%, and 58.0%, respectively. There were seasonal and regional differences in the vertical migration and distribution patterns of mesopelagic fishes in the South China Sea. A total of 228 species were identified, including 203 fish species, 23 cephalopod species, and 2 shark species. Among these, a subset of 43 fish and cephalopod species exhibited extensive diel vertical migrating behavior. Specifically, this subset comprised 23 lanternfish species, 8 cephalopod species, and 12 other fish species. Lanternfishes were the predominant diel vertical migratory species, while cephalopods also played a significant role in diel vertical migration. The diel migration behavior was found to be slight for Diaphus lucidus, Melamphaes microps, Argyropelecus affinis, and six other fish species. Non-migratory behavior was observed in Sternoptyx obscura, Argyropelecus sladeni, Sternoptyx diaphana, and 13 other fish species. The diel migration habits of 178 additional species of fish, cephalopods, and sharks could not be definitively determined

Electrochemical Behavior of Al(III) and Formation of Different Phases Al-Ni Alloys Deposits from LiCl-KCl-AlCl₃ Molten Salt

The electrochemical behaviors of Al(III) deposits on Ni substrates were investigated in LiCl-KCl-AlCl3 (2 wt.%) molten salts. Various electrochemical methods, including cyclic voltammetry (CV), square wave voltammetry (SWV), and open circuit chronopotentiometry (OCP) were used to explore the deposition processes of Al(III) on Ni substrates. Five kinds of Al-Ni alloys phase were firstly electrodeposited by the regulation of deposition potential form LiCl-KCl-AlCl3 (2 wt.%) molten salts at 753 K. The formation of Al-Ni alloys, such as AlNi3, Ni5Al3, AlNi, Al3Ni2, and Al3Ni were confirmed by X-ray diffractometer (XRD) and the cross-section morphologies were investigated by scanning electron microscope (SEM). Meanwhile, it was found that the temperature of molten salt was another key parameter for the controlling of alloys phase. No Al-Ni alloys phase other than AlNi3 and Ni5Al3 could be deposited at 703 K

In Situ Coprecipitation Formed Highly Water-Dispersible Magnetic Chitosan Nanopowder for Removal of Heavy Metals and Its Adsorption Mechanism

The requirement for enhanced, less expensive, and eco-friendly nanocomposites as an adsorbent is highly preferred for removal of heavy metals and in the major applications of environmental remediation. For widespread application prospects, a simple and cost-effective method for highly effective nanoadsorbent preparation is mainly studied. In this study, by using natural polymer chitosan (CS) and different iron ion precursors, a facile in situ one-step coprecipitation synthetic approach is used to develop water-dispersible chitosan/Fe3O4 nanocomposites. The physical and chemical properties of the synthesized magnetic chitosan nanopowder (MCNP) before and after adsorption were studied using FTIR, SEM, TEM, XRD, BET, and TGA instrumental methods. The adsorption efficiency was specifically studied by varying initial metal ion concentration, pH of the solution, and MCNP dosage for Pb­(II) and Cu­(II) as a model pollutant. The experimental data obtained are fitted by three adsorption isotherms and reaction kinetics models. The adsorption of Pb­(II) and Cu­(II) onto MCNP (1 g/L) followed a Langmuir adsorption isotherm with the highest adsorption capacity of 113.38 and 92.34 mg/g at pH = 5.5 and temperature 25 °C, respectively. The results of thermodynamic analysis show that the adsorption of Cu­(II) on MCNP is endothermic, while the Pb ions are exothermic. MCNP nanocomposite is regenerated by the EDTA-2Na-washing method and exhibited greater stability with reusability over usage of five times. Overall, the synthesized water-dispersible MCNP presented regeneration capability and stability toward the aqueous phase and is an excellent adsorbent for heavy metals removal processes

Optical transmission during mid-infrared femtosecond laser pulses ablation of fused silica

International audienceWe report on the optical transmission of near-infrared (1.8 μm) femtosecond laser pulses during multiple pulses laser ablation of fused silica surface. In addition to the previously reported ciliary white light phenomenon (Phys. Rev. Lett. 110, 097601 (2013)), two new optical transmission phenomena were observed for relatively low energy laser pulses. We systemically examined the damage morphologies of the ablation site as a function of laser pulse energy and laser shot number. Laser induced periodic surface structures (LIPSS) with different periods and orientations were observed for different pulse energy regimes. Comparison of the damage morphologies and the optical transmission reveals that the two new optical transmission phenomena origin from the refraction of the incident near-infrared pulses on the LIPSS covered damage surface followed by nonlinear propagation of the beamlets and even filamentation if the laser energy was high enough. We found that the interference of the neighboring white light emissions gives rise to radially orientated optical fringes. Based on this observation, we proposed another interpretation for the ciliary white light phenomenon

Cross-ancestry genome-wide association studies of brain imaging phenotypes

Genome-wide association studies of brain imaging phenotypes are mainly performed in European populations, but other populations are severely under-represented. Here, we conducted Chinese-alone and cross-ancestry genome-wide association studies of 3,414 brain imaging phenotypes in 7,058 Chinese Han and 33,224 white British participants. We identified 38 new associations in Chinese-alone analyses and 486 additional new associations in cross-ancestry meta-analyses at P < 1.46 x 10(-11) for discovery and P < 0.05 for replication. We pooled significant autosomal associations identified by single- or cross-ancestry analyses into 6,443 independent associations, which showed uneven distribution in the genome and the phenotype subgroups. We further divided them into 44 associations with different effect sizes and 3,557 associations with similar effect sizes between ancestries. Loci of these associations were shared with 15 brain-related non-imaging traits including cognition and neuropsychiatric disorders. Our results provide a valuable catalog of genetic associations for brain imaging phenotypes in more diverse populations