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The rational design of single atom‐based catalysts and precise elucidation of the synergistic interaction between the metal site and substrate are pivotal to identifying the real active sites and explicating the catalytic mechanisms at the atomic scale, thus contributing to the development of high‐performance catalysts for diverse industrial implementations. Herein, a Ru single‐atom doping strategy is developed to activate the MoC substrate with superior hydrogen evolution reaction (HER) activity in an alkaline medium. The atomically dispersed Ru sites are elaborately doped into MoC nanoparticles loaded on 3D N‐doped carbon nanoflowers (Ru‐SAs@MoC/NCFs hereafter). The experimental results and theoretical calculations manifest that the atomically isolated Ru dopants can effectively trigger the Mo sites with thermodynamically favorable water adsorption/dissociation energies and facilitate the OH− desorption on Ru sites and H adsorption on N sites, thus synergistically expediating the overall alkaline HER kinetics. As such, the well‐designed Ru‐SAs@MoC/NCFs demonstrate extraordinary HER activity with a low overpotential of 16 mV at 10 mA cm−2 in 1.0 m KOH electrolyte, outperforming Pt/C benchmark and a vast of molybdenum/ruthenium‐based HER catalysts reported to date. These findings disclose the alkaline HER mechanistic induced by the atomic doping modulation and suggest a design principle of high‐efficiency electrocatalysts via the atomic‐level manipulation leverage. [ABSTRACT FROM AUTHOR]

Despite over a decade of development, smart cities remain at a stage of visions and expectations. There is a dualist attitude in the smart cities literature, whereby the research either studies the content of visions or compares the visions with the innovation outcomes. What expectations actually do in a smart city innovation process is often neglected. This article addressed this gap by adopting an ethnographic approach and applying conceptual tools from the sociology of expectations and strategic niche management to study a UK smart city project – the Open Programmable Harbour City (OPHC). This study enriches the literature on smart city vision by showing that expectation played four complex and paradoxical roles in making the OPHC: (1) It tidied up the messy past and prescribed a future. (2) It provided limited coordination for innovation activities. (3) It helped to attract attentions to the OPHC, but it also caused disappointments. (4) It provided protection for the negative experimental results, but the overprotection also impeded innovation. This article concludes with four valuable lessons about expectation management for smart city innovators and some fresh theoretical insights for the sociology of expectations and strategic niche management. [ABSTRACT FROM AUTHOR]

Both forgetting to unplug mobile phone chargers after using and generating large surge current when the charger is plugged into power, will accelerate the aging of high-voltage electronic components. It is also prone to failure and fire. In addition, the charger consumes 100~800 mW power when it is in standby mode for a long time. Therefore, a fireproof and energy saving mobile phone charger is proposed. This kind of charger can reduce the standby power consumption to 13 mW, so it is unnecessary to pull out the charger to meet the habit of the users. It can absorb the surge current, meanwhile, it also has the functions of timing charging, overcurrent and short circuit protection, so as to prevent the occurrence of fire.

Understanding the spatial–temporal evolution of the blue–green space (BGS) is crucial for urban planning and ecological security protection. However, the evolutionary patterns and driving factors of the BGS in new urban districts remain unclear. Based on the classical qualitative models, "patch–corridor–matrix" and "sustainability prism", this study adopted the land use transition matrix and landscape index to quantify evolution patterns, and Pearson correlation and geographical detector analysis methods to reveal the driving factors. Taking Zhengdong New District as a case study, the results indicated the following: (1) The BGS rate was reduced by 35% from 2003 to 2021, with the most significant decrease in cultivated lands. (2) The evolution pattern of BGS alternated sequentially among ecological, disorderly, and balanced states. Among them, urban green spaces tended towards a more stable and aggregated state. Other BGSs became more fragmented and discontinuous. (3) The "sustainability prism" model consists of four driving factors, including social economy, rainwater safety, ecological liveability, and physical geography. (4) Socioeconomic factors significantly decreased the BGS, as indicated by the correlation coefficients of −0.988 and −0.978 between built-up areas and population and gross domestic products, respectively. Physical geographic factors played weak roles in the evolution of the BGS. Meanwhile, rainwater safety and ecological liveability positively affected the BGS. [ABSTRACT FROM AUTHOR]