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Abstract The modulation of the chemical microenvironment surrounding metal nanoparticles (NPs) is an effective means to enhance the selectivity and activity of catalytic reactions. Herein, a post‐synthetic modification strategy is developed to modulate the hydrophobic microenvironment of Ru nanoparticles encapsulated in a metal–organic framework (MOF), MIP‐206, namely Ru@MIP‐Fx (where x represents perfluoroalkyl chain lengths of 3, 5, 7, 11, and 15), in order to systematically explore the effect of the hydrophobic microenvironment on the electrocatalytic activity. The increase of perfluoroalkyl chain length can gradually enhance the hydrophobicity of the catalyst, which effectively suppresses the competitive hydrogen evolution reaction (HER). Moreover, the electrocatalytic production rate of ammonia and the corresponding Faraday efficiency display a volcano‐like pattern with increasing hydrophobicity, with Ru@MIP‐F7 showing the highest activity. Theoretical calculations and experiments jointly show that modification of perfluoroalkyl chains of different lengths on MIP‐206 modulates the electronic state of Ru nanoparticles and reduces the rate‐determining step for the formation of the key intermediate of N2H2*, leading to superior electrocatalytic performance.

In view of the natural endowment of mercury in fossil fuels and mineral resources, as well as the mercury emission controlling and regulating in the energy and resource utilization processes, the research and development on the mercury continuous emissions monitoring system (Hg-CEMS) with proprietary intellectual property rights is the most important requirement in science and technology in China. As a critical component of the Hg-CEMS system, the flue gas pretreatment system is a core technology that limits the development and application of the Hg-CEMS technology in China. This paper presents a comprehensive review of the research progress in the four key modules of the Hg-CEMS flue gas pretreatment technology, including the dilution sampling, Hg0/Hg2+ separation, Hg2+ reduction and Hg2+ calibration gas generation. Firstly, the dilution sampling techniques are highlighted in their characteristics and principles. The working principles, structures, and design considerations of the critical parameters for both critical hole and thermal dilution injectors are summarized. Emphasis is focused on the connection of numerical simulation with the optimal design methodology for the thermal dilution injector and critical hole. Secondly, regarding the Hg0/Hg2+ separation technology, various partitioning methodologies encompassing the wet absorption separation, physical adsorption separation and chemical adsorption separation are discussed. Particular attention is given to the separation and adsorption efficiency of the advanced dry chemical adsorption techniques involving the novel selective adsorbents of KCl and CaO with their updated theoretical and experimental outcomes under practical operating conditions. Thirdly, in aspect of the Hg2+ reduction technology, a comparative analysis of wet chemical reduction, low-temperature reduction and high-temperature reduction techniques is expatiated. Particular focus is on the active components of solid-state reducing agents, the impact of temperature on the reduction of divalent mercury, and the detrimental influences of flue gas components on the re-oxidation of the reduced elemental mercury in the low-temperature reduction techniques. An in-depth investigation of the impact of filler materials, acidic gas components and acid removal techniques on the reduction of divalent mercury in the high-temperature reduction techniques is highlighted. Finally, facing the technical problems, a solid generation method of the Hg2+ calibration gas is invented and its industrial utilization feasibility is verified in chemistry and experiments. In conjunction with the current status of research and application of the Hg-CEMS technology, the research technical routs, the solutions to some problems and development prospect for the above-mentioned four key modules are put forward.

Summary: Fluorescent anti-counterfeiting technology has been widely reported for its advantages, such as easy identification and multiple anti-counterfeiting functions. Most of the current fluorescent anti-counterfeiting materials focus on the innovation of anti-counterfeiting mode. However, stability is a prerequisite for applying anti-counterfeiting materials and determining whether a material can be widely used. Inspired by water stains, we report fluorescent nanoparticles that are easily prepared and inkjet printable and have multiple anti-counterfeiting functions and high stability. They are applied successfully to fluorescent anti-counterfeiting. 3D printed microreactors prepared the fluorescent nanoparticles with different emission wavelengths. The nanoparticles adhere firmly to the fibers of paper or cloth under the combined effect of hydrogen bonding and van der Waals forces. The sample paper exhibits good tolerance to extreme environments, such as boiling water, liquid nitrogen, photobleaching, and strong acid. Finally, multiple anti-counterfeiting functions are realized by mobile phones and clustering algorithms.

The effects of powder particle size， powder treatment technology and powder treatment environment on oxygen content of FGH95 alloy were studied by chemical composition analysis， scanning electron microscope， transmission electron microscope （TEM） and mechanical property detection. The results showed that the powder treatment environment had great influence on the oxygen content and microstructure of FGH95 alloy， and the oxygen content of the alloy was increased by 115% compared with that of the degassed alloy prepared in the inert gas environment after the atomized powder treated in air with the same particle size， the oxygen content of FGH95 alloy prepared in low oxygen environment was only 0.003 9%， which significantly improved the PPB structure in the alloy.Similarly the oxygen content of FGH95 alloy prepared by 0-45 μm powder increased by 33% than that by 0-75 μm powder after the degassed treatment at room temperature and 450 ℃ in the inert gas environment. Powder treatment temperature has little effect on oxygen content of alloy which prepared by powder treated in low oxygen environment under the same conditions. The FGH95 alloy with different oxygen content had little effect on the strength at room temperature， but the ductility of the alloy was decreased with the increase of oxygen content.