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Porous flower-like NiCoO 2 and graphene (NiCoO 2 /rGO) composite nanoarrays were grown directly on Ni foam (NF) without any binders by a simple hydrothermal synthesis method. Due to the porous flowers-like architecture of ultrathin NiCoO 2 nanoflakes and the introduction of graphene with the high electrical conductivity, NiCoO 2 /rGO composite nanoarrays showed superior electrochemical performance including high specific capacity (1286C g −1 at 0.5 A g −1 ), and good rate capability (1071.5C g −1 , 83.3% capacity retention at 12 A g −1 ). The asymmetric supercapacitor assembled with NiCoO 2 /rGO and rGO/NF also showed good performance with the energy density of 38.5 Wh kg −1 at 288 W kg −1 power density and good cycle stability of 86.9% after 2000 cycles. These results demonstrate the potential application of NiCoO 2 /rGO composite nanoarrays as a promising electrode material for supercapacitors. [ABSTRACT FROM AUTHOR]

Developing electrocatalysts with high-Pt-utilization efficiency and appropriate surface oxygen affinity through a facile and scalable route is urgently needed for proton exchange membrane fuel cells. Here, SPD-annealing strategy is demonstrated to prepare ordered low-Pt-loading Pd–Pt–Fe nanoalloys with an average particle size of less than 5 nm and excellent electrocatalytic performance. Furthermore, the ORR performances of Pd–Pt–Fe/C nanoalloy catalysts are rationally modified by means of both precise composition control and structural transformation. With an optimal component proportion, the prepared Pd 0. 75 Pt 0. 25 Fe/C catalyst exhibits the most excellent intrinsic activity due to the synergistic interaction of lattice strain and ligand effect. Benefiting from the compressive strain effect induced by the relatively tight arrangement of the ordered structure, the adsorption energy of the intermediate oxygen-containing species is effectively weakened, enabling the Pd 0. 75 Pt 0. 25 Fe/C to obtain enhanced ORR catalytic performance in acidic condition. Notably, compared with the disordered Pd 0. 75 Pt 0. 25 Fe/C, the ordered Pd 0. 75 Pt 0. 25 Fe/C shows an extremely superior stability of 98.5% mass activity retention after 10 000 cycles. This work could provide a facile and versatile approach to constructing the ordered low-platinum electrocatalysts with enhanced ORR properties. Benefiting from the strain effect of the ordered structure, the low-Pt ordered Pd–Pt–Fe/C nanocatalyst with enhanced ORR activity and exceptional cycle durability was synthesized via a facile SPD-annealing strategy. Image 1 • SPD-annealing method is developed to synthesize Pd–Pt–Fe/C catalysts with small particle size and enhanced ORR performance. • With an optimal component proportion, Pd 0.75 Pt 0.25 Fe/C nanocatalyst shows the most excellent intrinsic activity. • Benefiting from the strain effect, Pd 0.75 Pt 0.25 Fe/C exhibits exceptional stability (98.5% MA retention after 10000 cycles). • Our SPD-annealing strategy can enrich the alternatives for mass production of efficient ordered low-Pt ORR catalysts. [ABSTRACT FROM AUTHOR]

In application scenarios such as astronautics, high-altitude aircraft, medical radiography, high-energy physics, and nuclear power plants, the irradiation resistance of electronic components is one of the basic requirements for their reliability. HfO 2 -based ferroelectric films have the advantages of high CMOS process compatibility, good miniaturizability, low operating voltage, and excellent irradiation resistance, which are the core materials for the new generation of irradiation resistance ferroelectric memories. In this paper, two kinds of metal-electrode ferroelectric capacitors, W/Hf 0.5 Zr 0.5 O 2 /W (WW) and Pt/Hf 0.5 Zr 0.5 O 2 /Pt (PP), have been prepared, and three gradient γ-irradiation experiments have been carried out on the two kinds of ferroelectric capacitors. The effect of metal electrodes on the irradiation resistance of Hf 0.5 Zr 0.5 O 2 ferroelectric thin films was carefully investigated by comparing and analyzing the statistical laws of polarization change and rectangularity change before and after irradiation of a large number of devices. The experimental results show that the WW devices have better irradiation resistance than PP devices, and we further explain the irradiation resistance mechanism by first-principle calculations and finite element analysis to verify the credibility of the experimental results. Finally, we conducted a comparative test of the fatigue and wake-up characteristics of the WW devices before and after irradiation, and the results show that the prepared W/Hf 0.5 Zr 0.5 O 2 /W devices can withstand very high total γ-dose radiation, reaching up to 13.86 Mrad(Si), and they are very suitable for the application of irradiation resistant electronics. [Display omitted] • The Hf 0.5 Zr 0.5 O 2 (HZO) thin films with outstanding ferroelectric properties were prepared. • The HZO ferroelectric thin films exhibited extremely high radiation tolerance (reaching up to 13.86 Mrad(Si)). • The effect of different metal electrodes on the irradiation resistance of HZO ferroelectric thin films was analyzed. [ABSTRACT FROM AUTHOR]

Summary Mitogen-activated protein kinase cascades are important signaling modules that convert environmental stimuli into cellular responses. We show that MPK3, MPK4, and MPK6 are rapidly activated after cold treatment. The mpk3 and mpk6 mutants display increased expression of CBF genes and enhanced freezing tolerance, whereas constitutive activation of the MKK4/5-MPK3/6 cascade in plants causes reduced expression of CBF genes and hypersensitivity to freezing, suggesting that the MKK4/5-MPK3/6 cascade negatively regulates the cold response. MPK3 and MPK6 can phosphorylate ICE1, a basic-helix-loop-helix transcription factor that regulates the expression of CBF genes, and the phosphorylation promotes the degradation of ICE1. Interestingly, the MEKK1-MKK2-MPK4 pathway constitutively suppresses MPK3 and MPK6 activities and has a positive role in the cold response. Furthermore, the MAPKKK YDA and two calcium/calmodulin-regulated receptor-like kinases, CRLK1 and CRLK2, negatively modulate the cold activation of MPK3/6. Our results uncover important roles of MAPK cascades in the regulation of plant cold response. [ABSTRACT FROM AUTHOR]