Search

Abstract Nitrile rubber (NBR) is commonly used as a stator rubber for screw pumps because of its excellent mechanical properties. However, under hightemperature conditions, using NBR for long-term operations is [...]

Fewer layer graphene principally has a higher surface area to support more catalytic sites for energy conversion, but it is still challenging to synthesize monolayer graphene without oxidation from graphite at a low cost. Here, a method for synergistically thinning graphene layers and constructing catalytic sites to create a superior bifunctional oxygen catalyst through vapor intercalation of multi‐layer graphene or its derivatives is described. The synthesized small sheet sizes of 1–2 layer graphene‐supported FeN4 and FeCo active sites exhibit superior reversible activity of oxygen reduction and evolution reactions with a low overall overpotential of 0.648 V. The sheet‐shaped catalyst is further used to fabricate flexible soft‐packed and wearable cable‐type quasi‐solid‐state zinc–air batteries, achieving high performances (>188 mW cm−2, >450 cycles) and enabling smartphone charging. DFT calculations reveal that fewer layer graphene coupled with atomic FeN4 and alloy FeCo sites enables lower Gibbs free energy for favorable OOH* intermediate adsorption/desorption benefiting superior oxygen redox process. This study introduces a strategy for scalable synthesis of 1–2 layer graphene from cheap microcrystalline graphite minerals for wearable and durable energy devices. [ABSTRACT FROM AUTHOR]

In this study, we established a feasible fertilization programming method for wheat production by exploring the effects of the combined application of chemical and organic fertilizers on wheat yield, nutrient uptake, soil nutrient content, and fertilizer utilization. Six treatments, no fertilizer (CK), conventional fertilizer (CF), optimized fertilizer (with reduced fertilizer amount) (RF), chemical fertilizer with organic fertilizer extract (RPAE), partial replacement of chemical fertilizer with raw amino acid powder (RAF), and partial replacement of chemical fertilizer with raw humic acid powder (RHF), were set up for a field experiment. The fertilizer application rates for the RF treatment were calculated based on fertilization-monitoring techniques (30.3% nitrogen and 24.8% phosphorus reductions in 2022 and 23.0% nitrogen and 1.5% phosphorus reductions in 2023). The effects of different fertilizer treatments on yield, dry matter accumulation, plant nutrient accumulation, soil nutrients, and nutrient utilization in wheat were investigated. The results showed that, on the basis of 23% nitrogen and 1.5% phosphorus reductions, there was no significant difference in wheat yield between the RF and CF treatments and that the utilization rate of nitrogen fertilizer was improved. The application of organic fertilizer promoted dry matter accumulation in different organs of wheat; increased plant nutrient accumulation; improved soil nutrient content, nutrient utilization rate, nutrient partial productivity, and nutrient agronomic use efficiency; and ensured stable and increased crop yield. Specifically, compared with CF, the RPAE, RAF, and RHF organic fertilizer treatments increased wheat yield by 3.85%, 1.97%, and 0.67%, respectively, and the utilization of nitrogen and phosphorus fertilizers induced by these treatments significantly increased by 40.46%, 39.28%, and 37.46% (nitrogen) and by 9.83%, 8.91%, and 7.46% (phosphorus), respectively. As a result of our experiment, we concluded that RPAE exerted the best effects among the three organic fertilizer treatments (RPAE, RAF, and RHF) and that its use can result in a higher wheat yield and fertilizer utilization rate in drip-irrigated wheat fields. The results of this study provide a theoretical basis for the combined application of chemical and organic fertilizers, which is conducive to sustainable agriculture development. [ABSTRACT FROM AUTHOR]

We established friction models for pure NBR, GNS/NBR, and GO/NBR composites through molecular dynamics (MD) simulation. Our study focused on the impact of GNS and GO on the friction properties of nitrile rubber (NBR) composite materials after undergoing thermal oxygen aging. Based on the simulation results, it can be observed that the GNS/NBR and GO/NBR composites' coefficient of friction (COF) decreases by 20.8% and 24.8%, respectively, at 348 K. Additionally, the abrasion rate is reduced by 17.4% and 25.7%, respectively, for the same composites. Adding GNS and GO can effectively improve the friction performance of the NBR composite system, and compared with GNS, GO shows a better enhancement effect. Pure NBR and GO/NBR composite materials were prepared by mechanical blending method, and the friction properties of GO‐enhanced NBR composite materials were studied. The experimental results show that the GO/NBR composite material can maintain a low friction and wear coefficient after thermal and oxygen aging. It shows that adding GO can effectively improve the friction properties of NBR composite systems and slow down the weakening effect of aging on the friction properties of NBR composite materials. This is because the GO surface contains wealthy functional groups such as epoxy groups, which enhances the binding strength between the GO and NBR interface so that the GO/NBR composite material exhibits better friction properties and thermal oxygen aging resistance. In addition, the wear surface was characterized by scanning electron microscopy (SEM), revealing the damage mechanism of friction and wear of NBR composite materials. [ABSTRACT FROM AUTHOR]