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The high-frequency stability of soft magnetic composites could be substantially enhanced through the insulation coating process in which μf/μ100 kHz could reach 98.7% at 1 MHz.

Wheat straw, a typical agricultural solid waste, was employed to clarify the effects of torrefaction on the structural features and combustion reactivity of biomass. Two typical torrefaction temperatures (543 K and 573 K), four atmospheres (argon, 6 vol.% O2, dry flue gas and raw flue gas) were selected. The elemental distribution, compositional variation, surface physicochemical structure and combustion reactivity of each sample were identified using elemental analysis, XPS, N2 adsorption, TGA and FOW methods. Oxidative torrefaction tended to optimize the fuel quality of biomass effectively, and the enhancement of torrefaction severity improved the fuel quality of wheat straw. The O2, CO2 and H2O in flue gas could synergistically enhance the desorption of hydrophilic structures during oxidative torrefaction process, especially at high temperatures. Meanwhile, the variations in microstructure of wheat straw promoted the conversion of N-A into edge nitrogen structures (N-5 and N-6), especially N-5, which is a precursor of HCN. Additionally, mild surface oxidation tended to promote the generation of some new oxygen-containing functionalities with high reactivity on the surface of wheat straw particles after undergoing oxidative torrefaction pretreatment. Due to the removal of hemicellulose and cellulose from wheat straw particles and the generation of new functional groups on the particle surfaces, the ignition temperature of each torrefied sample expressed an increasing tendency, while the Ea clearly decreased. According to the results obtained from this research, it could be concluded that torrefaction conducted in a raw flue gas atmosphere at 573 K would improve the fuel quality and reactivity of wheat straw most significantly.

Exploiting advanced regenerable adsorbents for efficient uranium adsorption from seawater is a promising route to address uranium resources shortages. Herein, inspired by the mechanism of plant homeostasis, natural polyphenols are combined with cotton matrix to construct a polyphenol-functionalized cotton (Cot-TA-APTES) for efficient uranium extraction. Compared with pristine cotton, the polyphenol-functionalized cotton displays a rapid adsorption kinetic, and the maximum extraction efficiency for U(VI) is up 96.07% at pH 5.0 and 30[Formula: see text]C. Additionally, Cot-TA-APTES shows a higher adsorption selection ability for U(VI) than other interfering ions. Based on FT-IR and XPS, the excellent extraction efficiency and favorable selectivity of Cot-TA-APTES for U(VI) are due to the combination of U(VI) and functional coating groups. This natural polyphenol/cotton-based absolutely bio-derived adsorbent provides a novel and potentially applicable strategy for constructing an adsorbent for nuclear environmental remediation and uranium extraction from seawater with cost-effective and biosafety.

The oxygen-defect engineering of ZnO-400 nanosheets to enhance their photocatalytic performance for U(vi) reduction.

Constructing defects through the connection of Ru nanoparticles boosts their catalytic performance towards the electrochemical reduction of nitrogen.

Solid propellants with high safety, excellent thermal decomposition, and green performance are hot and difficult research areas in aerospace. In this paper, AP@HNS (hexanitrostilbene) composites with core-shell structure were designed and prepared by an ultrasound-assisted method using polyurethane for the interfacial modification of ammonium perchlorate (AP). The results show that the AP@HNS composites have a complete and dense shell structure when the nano-HNS content of the shell layer is 15% or more, the synergistic decomposition effect between HNS and AP can advance the high-temperature decomposition peak of AP by 102.4 °C and increase the apparent heat release 2.55 times to 1388 J g

A series of MXene/MnCo2O4.5 nanocomposites was successfully prepared by hydrothermal, ice crystal template and physical blend methods, respectively. Various characterizations indicated that hydrothermal method could successfully loaded MnCo2O4.5 nanoparticles on the surface of MXene nanosheets to obtain MMC-W nanocomposites with 3D flower-like structure, which could give MMC-W large specific surface area. The HTD temperature and decomposition heat of AP with adding 2.0 wt% MMC-W could significantly decrease to 304.7 °C and increase to 1310.9 J g-1, respectively. The lowest decomposition temperature (286.1 °C) and the highest heat release (1427.6 J g-1) of AP could be obtained by adding 8.0 wt% and 4.0 wt% of MMC-W, respectively. Moreover, MMC-W (2.0 wt%) could also significantly reduce the Ea of pure AP by 118.3 kJ mol-1 and increase the k value for AP by 11.2 times. The excellent catalytic performance of MMC-W was owing to the synergistic effect of nano-sized MnCo2O4.5 and MXene nanosheets. Owing to its high catalytic activity, MMC-W would be used as an excellent catalyst for ameliorating AP decomposition and supply an idea for the preparation of novel metal oxide nanoparticles.

The low voltage DC distribution networks are emerging as a great development trend for their flexible access to photovoltaic energy. However, there is no mature DC circuit breaker to protect DC fault. T-source circuit breakers can quickly and automatically cut off a fault current in a very short time. Compared with Z-source circuit breakers, T-source circuit breakers have greater advantages of zero reflected current, common ground, and capability of low-pass filtering. However, as a result of the high power loss of semiconductor devices, transmission efficiency is reduced. Therefore, this paper proposes a new efficient bidirectional T-source circuit breaker. The number of semiconductor devices that conduct in steadystate is reduced and therefore the on-state loss is reduced by more than 40% compared to the existing bidirectional T-source circuit breakers. The new circuit breaker can be manually turned off by reusing the capacitors. The soft starting circuit is also integrated into the circuit breaker. Finally, it is verified by simulation and experiment that the new circuit breaker has the capabilities of fault clearing, manual tripping, and soft starting.

Photocatalytic reduction of U(VI) represents a novel and effective manner for the removal of U(VI) pollutant from radioactive wastewater. Herein, we successfully incorporated hydrogen into VO2 nanosheets, which strengthened the interaction between VO2 and U(VI), thereby achieving a highly active and stable photocatalyst for U(VI) reduction. With the increase of H content in hydric VO2 (HX-VO2) nanosheets, the bandgap shrank from 2.29 to 1.66 eV, whereas the position of conduction bands remained more negative than the reduction potential of U(VI)/U(IV) (0.41 V vs. NHE). When irradiated by simulated sunlight, the U(VI) removal efficiency over H0.613-VO2 nanosheets reached up to 95.4% within 90 min, which largely outperformed 28.3% of pristine VO2 nanosheets. The mechanistic study demonstrated that the hydroxylated surface gave rise to the balanced O confinement sites in VO2 (011), leading to the stabilized adsorption configuration and increased binding strength of UO22+ on HX−-VO2 nanosheets.

Biochar always suffers from low porosity and/or poor surface functionality, which limit its performances. Among various surface engineering strategies, air oxidation favors both pore development and surface oxygenation for biochar. However, there is still a lack of systematic knowledge and critical perspective on air oxidation in surface engineering of biochar-based materials for various applications. Herein, this review analyzed the mechanisms of air oxidation, summarized the routes of air oxidation in surface engineering of biochar-based materials, investigated the impacts of controlling factors (including operation parameters and intrinsic biochar structure) on pore development and surface oxygenation during air oxidation, and discussed the performances of the resultant materials in pollution control, biomass catalytic conversion and energy storage. This review suggested that air oxidation could be conducted in oxidative torrefaction/pyrolysis, and applied as post-modification or pretreatment processes. Interestingly, air oxidation is efficient in enriching the heteroatoms in the heteroatom-doped biochar, and promoting the doping of metal species on biochar by enriching the anchor sites. This review also highlighted the future challenges concerning air oxidation in the surface engineering of biochar-based materials. Finally, this review was intended to attract broad attention and inspire new discoveries for promoting the application of air oxidation in surface engineering of biochar-based materials for various advanced applications. Graphical Abstract

Reduction of hexavalent uranium [U(VI)] by the photocatalytic method opens up a novel way to promote the selectivity, kinetics, and capacity during uranium removal, where organic molecules act as the sacrificial agents. However, the addition of sacrificial agents can cause a secondary environmental pollution and increase the cost. Here, a UiO-66-based photocatalyst (denoted as MnO

Actinide-based catalysts have been regarded as promising candidates for N

An environment-friendly, low-cost and efficient kaolin aerogel adsorbent (named as KLA) was synthesized via a freeze-drying-calcination method to solve the defect of low uranium removal rate for kaolin (KL). The removal rate of uranium on KLA reached 90.6 %, which was much higher than that of KL (69.2 %) (C

Electrochemical extraction of uranium in seawater provides a promising strategy for the persistent supply of fuel in the nuclear industry. However, current operation voltage for the electrochemical extraction of uranium in seawater generally requires a high applied voltage (∼-5 V). Herein, we constructed S-terminated MoS

As a radioactive heavy metal element with a long half-life, uranium causes environmental pollution when it enters the surrounding soil. This study analyzed the changes about soil enzyme activity, non-targeted metabolomics, microbial community structure and function microbial community structure and function to assess the differences in the effects of uranium stress on rhizosphere and non-rhizosphere soil. Results showed that uranium stress significantly inhibited the activities of urease and sucrase in rhizosphere and non-rhizosphere, which had less effect on rhizosphere. Compare to the non-rhizosphere soil, the uranium stress induced the production of gibberellin A1, to promoted several metabolic pathways, such as nitrogen and PTS (Phosphotransferase system) metabolic in rhizosphere soil. The species and abundance of Aspergillus, Acidobacter, and Synechococcus in both rhizosphere and non-rhizosphere soil were decreased by uranium stress. However, the microorganisms in rhizosphere soil were less inhibited according to the soil metabolism and microbial network map analysis. Furthermore, the Chujaibacter in rhizosphere soil under uranium stress was found significantly positively correlated with lipid and organic oxygen compounds. Overall, the results indicated that ryegrass roots significantly alleviated the effects of uranium stress on soil microbial activity and population abundances, thus playing a protective role. The study also provided a theoretical basis for in-depth understanding of the biological effects, prevention and control mechanisms of uranium-contaminated soil.