Design and preparation of FeNiCoCrY high-entropy alloy nanopowders with sustained, efficient and rapid degradation properties of CR and Cr(VI) wastewater.

In this paper, magnetic nanopowders of Fe19.5Ni40Co19.5Cr19.5Y1.5 high-entropy alloy compositions were successfully prepared by the liquid phase reduction method, which represented a breakthrough from the traditional process of preparing high-entropy alloy nanopowders. The powders had a high specific surface area of 136.23 m2/g and exhibited sustained, efficient, and rapid degradation characteristics for high concentrations of CR and ultra-high concentrations of Cr(VI) wastewater. It was demonstrated that the removal rate of CR remained at 100 % after 100 cycles and 81 % of Cr after 8 cycles of the powder without changing the pH and room temperature. The powders also demonstrated good soft magnetic properties, which allowed them to be conveniently separated and recycled using magnetic field treatment, thus addressing the issue of recycling raw materials without causing secondary pollution in wastewater treatment. Furthermore, the analyzed powders also exhibited fast and efficient degradation effects.

NiCoCrFeY High Entropy Alloy Nanopowders and Their Soft Magnetic Properties.

High entropy alloy nanopowders were successfully prepared by liquid-phase reduction methods and their applications were preliminarily discussed. The prepared high entropy alloy nanopowders consisted of FeNi alloy spherical powders and NiFeCoCrY alloy spherical powders with a particle size of about 100 nm. The powders have soft magnetic properties, the saturation magnetization field strength were up to 5000 Qe and the saturation magnetization strength Ms was about 17.3 emu/g. The powders have the excellent property of low high-frequency loss in the frequency range of 0.3-8.5 GHz. When the thickness of the powders coating was 5 mm, the powders showed excellent absorption performance in the Ku band; and when the thickness of the powders coating was 10 mm; the powders showed good wave-absorbing performance in the X band. The powders have good moulding, and the powders have large specific surface area, so that the magnetic powder core composites could be prepared under low pressure and without coating insulators, and the magnetic powder cores showed excellent frequency-constant magnetization and magnetic field-constant magnetization characteristics. In the frequency range of 1~100 KHz; the µm of the magnetic powder core heat-treated at 800 °C reached 359, the µe was about 4.6 and the change rate of µe with frequency was less than 1%, meanwhile; the magnetic powder core still maintains constant µe value under the action of the external magnetic field from 0 to 12,000 A/m. The high entropy alloy nanopowders have a broad application prospect in soft magnetic composites.

Environmental Friendly Modification of the Superhydrophobic Surface for Iron-Based Amorphous Alloy Films and Their Magnetic Surface Effect.

It is challenging to convert the superhydrophobic surfaces of iron-based amorphous films into hydrophilic surfaces through surface treatment. In this study, a novel, environmentally friendly method is used to change the superhydrophobic surfaces of Fe78Si13B9 amorphous alloy films, which include their rougher and smoother surfaces. The boron element in the films reacted with the flavonoids and anthocyanins in the solution to create organic conversion membranes and organic boronizing naphthoquinone derivatives on the surfaces of the films when they were dipped in tea polyphenol aqueous solution at 80 °C for 60 min. On the rougher surface and the smoother surface, the organic conversion membranes had thicknesses of about 10 and 3 µm, respectively. When iron-based amorphous alloy films were employed as soft magnetic materials to create electronic and electrical devices, the packaging issue caused by low wettability with epoxy resin had been resolved because both the side surfaces of modified films had good wettability with epoxy resin. In addition, the magnetic surface effect of modified films was significant. After surface treatment, the inductance value of the film decreased by more than 25%. The magnetic surface effect of iron-based amorphous films can be applied to the preparation of tea sensors, and the sensor can achieve the "one to one" high precision test of "one tea curve". The magnetic surface effect of the film provides a quick, simple, lower cost, and strong anti-interference idea for the rapid detection of tea polyphenols.

Flooding duration affects the temperature sensitivity of soil extracellular enzyme activities in a lakeshore wetland in Poyang Lake, China.

Extracellular enzymes play central roles in the biogeochemical cycles in wetland ecosystems. Their activities are strongly impacted by hydrothermal conditions. Under the ongoing global change, many studies reported the individual effects of flooding and warming on extracellular enzyme activities, however, few researches investigated their interactive effects. Therefore, the current study aims to determine the responses of extracellular enzyme activities to warming in wetland soils under divergent flooding regimes. We investigated the temperature sensitivity of seven extracellular enzymes related to carbon (α-glucosidase, AG; ß-glucosidase, BG; cellobiohydrolase, CBH; ß-xylosidase, XYL), nitrogen (ß-N-acetyl -glucosaminidase, NAG; leucine aminopeptidase, LAP), and phosphorus (Phosphatase, PHOS) cycling along the flooding duration gradient in a lakeshore wetland of Poyang Lake, China. The Q10 value, calculated using a temperature gradient (10, 15, 20, 25, and 30 °C), was adopted to represent the temperature sensitivity. The average Q10 values of AG, BG, CBH, XYL, NAG, LAP, and PHOS in the lakeshore wetland were 2.75 ± 0.76, 2.91 ± 0.69, 3.34 ± 0.75, 3.01 ± 0.69, 3.02 ± 1.11, 2.21 ± 0.39, and 3.33 ± 0.72, respectively. The Q10 values of all the seven soil extracellular enzymes significantly and positively correlated with flooding duration. The Q10 values of NAG, AG and BG were more sensitive to the changes in flooding duration than other enzymes. The Q10 values of the carbon, nitrogen, and phosphorus-related enzymes were mainly determined by flooding duration, pH, clay, and substrate quality. Flooding duration was the most dominant driver for the Q10 of BG, XYL, NAG, LAP, and PHOS. In contrast, the Q10 values of AG and CBH were primarily affected by pH and clay content, respectively. This study indicated that flooding regime was a key factor regulating soil biogeochemical processes of wetland ecosystems under global warming.

The determining factors of sediment nutrient content and stoichiometry along profile depth in seasonal water.

In the recent decades, the area of seasonal water (SEW) has substantially increased at the global scale. To evaluate nutrient dynamics in aquatic ecosystems, previous studies have analyzed the determining factors of sediment nutrient content and stoichiometry on whole sediment profiles without depth separation on SEW sites. Such a methodology assumes that SEW sediment is a uniform unit and its nutrient dynamics are regulated by the same mechanism at various depths (uniformity assumption). We tested this assumption using sediment samples from six depth increments of 154 sediment profiles (1 m depth) on SEW sites at Shengjin Lake in subtropical China. We measured sediment total nitrogen (STN), total phosphorus (STP), nutrient fractions, and the molar ratio of STN to STP (RSNP), and investigated their determining factors at various depths. STN, STP, and RSNP were averaged at 1.34 g/kg, 0.55 g/kg, and 5.43, respectively, and all gradually decreased with depth. STN was positively affected by moisture and flooding duration in all depth increments. Instead, the major determining factors of STP changed from particle size at 0-20 cm of depth to pH and electrical conductivity at 30-100 cm of depth. These vertical patterns have close connections with sediment nutrient fractions since sediment N fractions did not shift along profile depths (i.e., over 99 % of STN was organic N) but sediment P fractions did (the percentage of Fe-P and Al-P decreased by 6.25 % but those of Ca-P increased by 4.31 % along the sediment depth gradient). The major determining factors of RSNP showed no obvious vertical patterns because they frequently varied along depth gradients. The results demonstrate that SEW sediment is not a uniform unit and the determining factors of nutrient dynamics change with depth. Our study highlights the importance of improved methodological reflection in studies addressing sediment nutrient dynamics on SEW sites.