Conventional cutting fluids often rely on non-renewable mineral oils and hazardous additives, raising serious environmental and occupational safety concerns. Developing green, high-performance alternatives is therefore imperative for advancing sustainable manufacturing. Amphiphilic Fe3O4@SiO2-C12 core-shell nanoparticles were synthesized and used to stabilize vegetable oil-in-water Pickering emulsions as novel nano-cutting fluids. Systematic characterization confirmed the successful formation of superparamagnetic nanoparticles with tunable wettability. Response surface methodology (RSM) optimized the formulation to pH 8.9, 2.9 wt% cottonseed oil, and 0.18 wt% nanoparticles, achieving a zeta potential of-42.533 mV and wear scar diameter of 0.393 mm. The optimized Pickering emulsion demonstrated superior performance versus the commercial cutting fluid, including a low friction coefficient of 0.0666, a 17.09% reduction in wear scar diameter, a 10.21% decrease in tapping torque, and a 15.40% enhancement in thermal conductivity (0.645 W/(m & sdot;K)). X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM)-energy-dispersive spectroscopy (EDS) revealed a triple synergistic lubrication mechanism involving physical adsorption, tribochemical Fe2O3/FeO film formation, and nanoparticle-enabled micro-bearing and heat conduction. The Pickering emulsion also demonstrated excellent magnetic responsiveness, enabling rapid, magnetically controlled demulsification and oil-water separation for recycling. In this work, a high-performance and environmentally friendly cutting fluid was developed and evaluated for sustainable manufacturing applications.
Panicle-grain nitrogen (PGN) supply effectively promotes rice grain filling and increases yield, but its effects on grain filling under reduced drip irrigation and the underlying physiological mechanisms are unclear. A three-year field experiment (2023-2025) evaluated the effects of two drip irrigation amounts (D1, 10,200 m3 ha-1; D2, 8966 m3 ha-1) and three PGN levels (N60, 60 kg ha-1; N120 (CK), 120 kg ha-1 ; and N180, 180 kg ha-1 ) on rootshoot endogenous hormone levels, grain-filling characteristics and yield in rice. Compared with those under D1, under D2, the abscisic acid (ABA) content increased by 10.7%, and the timing of peak ABA accumulation and maximum grain filling rate occurred earlier in the inferior grains; however, the active inferior-grain filling period was shortened by 2.8 days, and the yield decreased by 3.1-9.0% under D2. Compared with N60, the N120 and N180 treatments increased spikelet-root activity (SRA) by 5.0-244.9% and indole-3-acetic acid (IAA) levels and IAA/ ABA ratios in roots, leaves, and grains by 2.3%-242.6%, thereby increasing the mean grain-filling rate (Gmean) by 0.8-9.5%. PLS-PM revealed that under D2, inferior grain filling was positively associated with yield. Notably, compared with D1N120, D2N180 altered the IAA metabolic characteristics of inferior grains, increasing SRA (19.4%) and Gmean (8.24%), while maintaining a relatively high grain yield. In conclusion, the application of 180 kg ha-1 panicle-grain nitrogen fertilizer under reduced drip irrigation (8966 m3 ha-1) improved inferior grain filling by increasing root physiological activity and regulating the IAA/ABA balance, thereby maintaining a higher yield.
To clarify microscopic competitive adsorption characteristics of methane (CH4) and carbon dioxide (CO2) on coal surfaces, a constitutive model for CO2-CH4 competitive adsorption on coal surfaces is derived based on the Lennard-Jones intermolecular potential theory. The model accuracy has verified against both molecular dynamics simulation results and competitive adsorption experimental data. Model analysis results reveal that: the densities of CO2 and CH4 both increase initially and then decrease with decreasing distance from coal surface. The location of maximum CO2 density is closer to the surface than that of CH4, which is a characteristic parameter characterizing the CO2 competitive adsorption superiority. The average molar fraction of CO2 in adsorption region is significantly higher than that in the free phase. The CO2 competitive adsorption selectivity coefficient decreases by a power law and gradually approaches 1 with increasing CO2 mole fraction in free region. The CO2 competitive adsorption superiority weakens significantly when the CO2 mole fraction in free region exceeds 40%. During pressurization below 10 megapascal (MPa), the free CO2 gradually transforms into the adsorbed state, and CO2 competitive adsorption superiority is enhanced. The CO2 competitive adsorption selectivity coefficients show linearly upward trend with increasing pressure and power-law downward trend with increasing temperature.
To address the issues of random distribution of Lewis acid/base sites in constructing heterogeneous Frustrated Lewis pairs (FLPs) on porous carbon and the scarcity of reports on B/P-based FLPs, we propose this work proposes a precursor design strategy in which P and B are co-introduced through a single MOF precursor: A B and Pcontaining MOF precursor (BF4- @PM) is synthesized using Co(BF4)2 and phenylphosphonic acid, in which the P source is anchored to the framework via coordination bonds, the B source is positioned adjacent to the coordination layer through electrostatic interactions, and the metal nodes physically isolate B and P to prevent premature complexation, thereby presetting their spatial proximity. After carbonization, the metal nodes are removed by HF etching, exposing neighboring unsaturated B and P sites to construct B/P-based heterogeneous FLPs, denoted as PM-PCs. PM-800 exhibits a CO2 adsorption capacity of 26.9 cm3/g at 273.15 K. Its adsorption isotherm can be well described by the Freundlich model, and the adsorption process is spontaneous and exothermic, suggesting favorable interactions between the material and CO2 molecules. PM-700 delivers a catalytic yield of 87.9% in the cycloaddition reaction of CO2 with epoxides and presents favorable cycling stability, which originates from the synergistic effect between high-density FLPs sites and well-developed porosity. This work offers a new strategy for fabricating robust heterogeneous FLPs-based catalysts toward CO2 involving reactions.
CO-mediated selective catalytic reduction of NO (CO-SCR) enables the simultaneous elimination of NO and CO, two prevalent toxic pollutants in industrial flue gas, and thus serves as a promising and practical purification technology. Carbon-based catalysts are widely employed in CO-SCR systems due to their intrinsic oxygen resistance. However, conventional thermal catalysis necessitates high-temperature operation, which induces carbon supports to participate in NO reduction and generate secondary pollutants, thereby causing catalyst corrosion and support consumption. We address this long-standing technical dilemma via a photogenerated charge transfer strategy based on a RuO2/g-C3N4 heterojunction. In-situ irradiated XPS and density functional theory calculations confirm that photoelectrons transfer from g-C3N4 to RuO2 under light irradiation. Such charge redistribution strengthens the adsorption of NO and CO, weakens O2 chemisorption, and reduces the energy barrier for N–O bond cleavage from 0.49 eV to 0.45 eV. Consequently, the catalyst achieves 100% conversion of both NO and CO at 250 °C, which is lower than the corrosion threshold of carbon substrates, fundamentally eliminating support corrosion. More notably, the catalyst maintains 100% NO conversion even in flue gas containing 5% O2. This work develops a robust, stable catalyst with excellent oxygen resistance for low-temperature CO-SCR reactions and establishes a general charge-transfer design principle for the construction of high-performance, oxygen-tolerant photothermal catalysts.
