Electrochemical deuteration utilizing D2O is a promising room-temperature strategy for synthesizing deuterated molecules. At present, high Faradic efficiencies (FEs) at high reaction rates are extraordinarily significant but highly challenged. Here, high-curvature low-coordinated copper nanotips (LC-Cu NTs) are designed to enable electroreductive deuteration of α-deuterio aryl acetonitriles, in situ generated from fast α-H/D exchange of acetonitriles in D2O, to α,β-deuterio arylethyl primary amines with 90% FE and 0.11 mmol h-1 cm-2, greatly outperforming the reported data and other Cu counterparts. The increased electric fields of the nanotips concentrate nitriles and K+(D2O)n, and low-coordination sites promote nitriles and D2O adsorption, thus facilitating nitrile deuteration with an excellent reaction rate. The higher coupling energy barrier of active hydrogen atoms at low-coordination sites restricts the D2 evolution, accounting for the outstanding FE. The wide substrate scope, easy gram-scale synthesis, and facile preparation of d4-melatonin with enhanced antitumor and antioxidation effects highlight its great promise. Furthermore, the application of LC-Cu NTs in other deuteration reactions with improved reaction rates and FEs rationalizes the design concept.
This paper proposes a functional carriage design and an evaluation index system to improve the operational efficiency of high-speed medical trains. Hierarchical task analysis and human-machine-environment analysis were applied to model the transfer task and the functional modules of the medical train. The functional module configuration was obtained by performing a correlation analysis between the task and function. The relationship between carriages was elucidated by analysing material, personnel and information flow, and an optimal grouping diagram was obtained. Based on this design method, an innovative 6-carriage grouping design scheme was proposed. A functional evaluation index system for the carriage design was constructed, and the 6-carriage design was compared with the conventional 8-carriage design to verify the usability of the design method. The results showed that the 6-carriage high-speed trains can be flexibly configured to suit the changing task environment and are generally better than the 8-carriage design. This study provides theoretical and methodological support for constructing efficient and rational functional carriages for high-speed medical trains.
The room temperature selective hydrogenation of quinolines to 1,2,3,4-tetrahydroquinolines (THQs) using a safe and clean hydrogen donor catalyzed by cost-effective catalysts is significant but challenging because of the difficult activation of quinolines and H2. Here, a fluorine-modified cobalt catalyst is synthesized via electroreduction of Co(OH)F precursor that exhibits high activity for electrocatalytic hydrogenation of quinolines by using H2O as the hydrogen source to produce THQs with up to 99% selectivity and 94% isolated yield under ambient conditions. F is revealed to enhance the adsorption of quinolines, and promote water activation to produce active atomic hydrogen (H*) by forming F−-K+(H2O)7 networks. A unique 1,4/2,3-addition pathway involving H* is proposed by combining experimental and theoretical results. Wide substrate scopes, scalable synthesis of bioactive precursors, expedient fabrication of deuterated analogues, and paired synthesis of tetrahydroquinoline and industrially important adiponitrile at a low voltage highlight the promising application of this methodology.
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