The construction of the highly active transition-metal phosphide/carbon-based electrocatalyst from metal-organic frameworks (MOFs) precursors is considered as an efficient approach. In this work, ZIF-67/GO precursors were firstly obtained by the in situ controllable growth of ZIF-67 nanocrystals on both surfaces of GO sheets. Then, a highly efficient bifunctional electrocatalyst CoP/Co@NPC@rGO nanocomposite was derived by the thermal pyrolysis of ZIF-67/GO precursors under N₂ atmosphere and a subsequent phosphatization process. The structure and elemental composition of the ZIF-67/GO, Co@NPC@rGO, and CoP/Co@NPC@rGO nanocomposites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and N₂ ad-/desorption isotherms analysis. The Co@NPC@rGO‒800 nanocomposite exhibits a high Brunauer-Emmett-Teller (BET) surface area of 186.27 m²·g^‒1, indicating that both micropores and mesopores existed. Subsequently, the electrocatalytic properties of the CoP/Co@NPC@rGO nanocomposites for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) were investigated by electrochemical measurements. The results suggest that the obtained CoP/Co@NPC@rGO‒350 nanocomposite only requires an overpotential of 127 mV to reach a current density of 10 mA·cm^‒2 for HER in 1.0 mol·L^–1 KOH solution. For OER, CoP/Co@NPC@rGO‒350 nanocomposite can reach a current density of 10 mA·cm^‒2 at an overpotential of 276 mV, with a Tafel slope of 42 mV·dec⁻¹, in the same alkaline aqueous solution, which is superior to RuO₂. In addition, for both HER and OER, CoP/Co@NPC@rGO‒350 nanocomposite also shows impressive strong durability in alkaline aqueous solution. The outstanding performance can be attributed to the synergistic effect of coupled highly graphitized N-doped porous carbon and N-doped graphene. The as-prepared CoP/Co@NPC@rGO‒350 electrocatalyst is a promising candidate for overall water splitting in the alkaline solution. This development offers an attractive catalyst material based on MOF/GO composites. It is expected that the presented strategy can be extended to the fabrication of other composites electrode materials for more efficient water splitting.

In order to improve the energy efficiency of the diesel-electric hybrid propulsion system, a control strategy suitable for hybrid electric propulsion ships is proposed. The state of charge of the lithium battery pack is taken as the state parameter, according to the load change trend under different electric loads and the best diesel generator fuel consumption rate curve, to achieve the optimal increase and decrease machine control under multiple networking conditions, and the optimal load adjustment under a single network condition. The simulation results show that by controlling the number of generators in the network and setting the power load of a single generator, the optimal load adjustment under a single network condition. The simulation results show that by controlling the number of generators in the network and setting the power load of a single generator,

The optical navigation errors of Mars probe in the capture stage depend closely on which targets are selected to be observed in the Mars system. As for this problem, a novel integrated navigation scheme is proposed wherein the optical observation is aided by one-way Doppler measurements. The errors are then analyzed respectively for the optical observation and one-way Doppler measurements. The real-time calculating scheme which exploits the EKF framework is designed for the integrated navigation. The simulation tests demonstrate that the errors of optical navigation, which selects the Mars moon as the observation target, are relatively smaller than that in the Mars-orientation optical navigation case. On one hand, the integrated navigation errors do not depend on the selecting pattern of optical observation targets. On the other hand, the integrated navigation errors are significantly reduced as compared with that in the optical-alone autonomous navigation mode.