Surface Technology (表面技术)•2026•DOI: 10.16490/j.cnki.issn.1001-3660.2026.11.009
Rotary tiller blades suffer continuous abrasive wear from soil, sand, and crop residues, causing premature failure and high replacement costs. Conventional overlapping laser cladding consumes excessive powder and generates interfacial defects. This study designed and fabricated four non-overlapping textured Ni60A-WC (20%) composite coatings with grooves on 245-type 65Mn steel blades: perpendicular to blade edge, parallel to blade edge, vertical cross (90° intersection), and oblique cross (45° intersection). Grooves enable soil self-filling to form a protective layer. Discrete element method (EDEM) simulations identified stress concentration at the forward cutting edge, side cutting edge, and their junction. Field tests compared textured, untextured, and ordinary blades. The vertical cross texture exhibited the best wear resistance, with a wear rate of only 2.33%, an 80% reduction versus ordinary blades, while reducing cladding powder consumption by 67% (4.1 g vs. 18.6 g for traditional overlapping). Wear data correlated with simulated cumulative contact force. Laser confocal microscopy showed the wear area of the vertical cross texture (852.559 μm²) was only 18% of that of the perpendicular texture. The wear mechanism involves soil and sand filling the grooves to form a soft-hard alternating self-filling wear-resistant coating parallel to the cutting direction, enabling a fill-wear-refill dynamic cycle. This approach reduces powder usage while enhancing wear resistance.
Nano-Micro Letters (纳微快报)•2026•DOI: 10.1007/s40820-025-01903-0
By combining the merits of radiative cooling (RC) and evaporation cooling (EC), radiative coupled evaporative cooling (REC) has attracted considerable attention for sub-ambient cooling purposes. However, for outdoor devices, the interior heating power would increase the working temperature and fire risk, which would suppress their above-ambient heat dissipation capabilities and passive water cycle properties. In this work, we introduced a REC design based on an all-in-one photonic hydrogel for above-ambient heat dissipation and flame retardancy. Unlike conventional design RC film for heat dissipation with limited cooling power and fire risk, REC hydrogel can greatly improve the heat dissipation performance in the daytime with a high workload, indicating a 12.0 °C lower temperature than the RC film under the same conditions in the outdoor experiment. In the nighttime with a low workload, RC-assisted adsorption can improve atmospheric water harvesting to ensure EC in the daytime. In addition, our REC hydrogel significantly enhanced flame retardancy by absorbing heat without a corresponding temperature rise, thus mitigating fire risks. Thus, our design shows a promising solution for the thermal management of outdoor devices, delivering outstanding performance in both heat dissipation and flame retardancy.
New Carbon Materials (新型炭材料)•2025•DOI: 10.1016/S1872-5805(NCM2025-40-01-13)
Carbon materials with adjustable porosity, controllable heteroatom doping and low-cost have been received considerable attention as supercapacitor electrodes. However, using carbon materials with abundant micropores, a high surface area and a high-dopant content for an aqueous supercapacitor with a high energy output still remains a challenge. We report the easy synthesis of interconnected carbon spheres by a polymerization reaction between p-benzaldehyde and 2,6-diaminopyridine. The synthesis involves adjusting the mass ratio of the copolymer and KOH activator to achieve increased charge storage ability and high energy output, which are attributed to the high ion-accessible area provided by the large number of micropores, high N/O contents and rapid ion diffusion channels in the porous structure. At a PMEC∶KOH mass ratio of 1∶1, the high electrolyte ion-adsorption area (2599.76 m2 g−1) and the N/O dopant atoms of the conductive framework of a typical carbon electrode produce a superior specific capacity (303.2 F g−[email protected] A g−1) giving an assembled symmetric capacitor a high energy delivery of 11.3 Wh kg−1@250 W kg−1. This study presents a simple strategy for synthesizing microporous carbon and highlights its potential use in KOH-based supercapacitors.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2025•DOI: 10.1016/j.ijmst.2025.07.012
Gob-side entry retaining (GER) is widely applied in China. Nevertheless, the stability mechanism of the GER with coal pillar-backfill body (CPBB) under dynamic overburden load remains unexplored. A voussoir beam structure (VBS) model is established to analyze roof structure stability during panel advancement, introducing a VBS stability criterion. Reducing block B length l and immediate roof damage variable D, and increasing coal pillar width xc, lowers the GER structure instability risk. Reducing l and the GER width w leads to a CPBB system stability upswing. A UDEC model was established to systematically reveal how the l, backfill body width xb, and strength affect the stability and coupling performance of the CPPB system by monitoring the crack damage DC. Simulation results indicate that at l=14 m, xb=2.0 m, water-cement ratio 1.5:1, the coal pillar and backfill body have similar DC but maintain stability, resulting in CPPB system coupling degree Ϗ, better. A novel GER method supported by the CPBB was implemented on-site. Monitoring results indicated that the coal pillar peak stresses were 19.17 MPa (ahead), 16.14 MPa (behind), and the backfill body peak stress was 12.27 MPa (maximum). The floor heave was 380 mm, with a 103 mm backfill body rib.
Journal of Central South University•2025•DOI: 10.1007/s11771-025-6052-x
Indium (In) has been used as a thermal interface material (TIM1) in high-performance central processing unit (CPU) for better heat dissipation. However, leakage or pump-out of liquid indium during the multiple reflow cycles limits its application in advanced flip chip ball gray array (FCBGA) packaging. Former researchers place a seal or dam structure to prevent In leakage, leading to the risk of In explosion, thermal degradation, or require additional keep-out zones. In this work, a copper foam (CF) matrix was embedded in In to absorb the liquid In and eliminate the leakage of In TIM1 during the multiple reflow cycles, as the CF capillary force. Au/Ni/Cu-Au/Ni/Cu joint was fabricated by soldering with the composite solder at 190 ℃ for 2 min. After reflow cycles, good metallurgical bonding was formed at interfaces of joint. Rod-like Cu11In9 formed at the CF and In interface, due to the re-dissolved of Cu11In9 crystal. Small amount of Cu atoms from CF can reduce the activity of In, which inhibits the growth of Ni3In7 intermetallic compound (IMC) at the interface of In and Au/Ni/Cu substrate. The CF matrix also improved the shear strength (22.9%) and thermal conductivity of the solder joints. Besides, the fracture behavior of solder joints without CF matrix was classified to be ductile type while that with CF matrix was changed to be ductile-brittle mixed type.