Acetylene is an important industrial gas for the production of vinyl chloride and 1,4-butynediol, but its storage remains a major challenge because it is highly explosive. Flexible metal–organic frameworks (FMOFs) are always at the forefront of porous materials due to the transformation of the structure under the external stimuli. In this work, divalent metal ions and multifunctional aromatic N,O-donor ligands were chosen, and three FMOFs [M­(DTTA)2]·guest [M = Mn (1), Cd (2), and Cu (3)] (H2DTTA = 2,5-bis­(1H-1,2,4-trazol-1-yl) terephthalic acid) have been successfully constructed. Single-crystal X-ray diffractions show that these compounds are isostructural and feature a three-dimensional framework. Topological analysis shows a (4, 6)-connected network with a Schläfli symbol of {44.610.8}­{44.62}. All three compounds exhibit breathing behavior on N2 adsorption at 77 K, and due to the difference of ligand torsion angles, compounds 2 and 3 exhibit extraordinary adsorptions for C2H2 of 101 and 122 cm3 g–1 at 273 K under 1 bar, respectively. Compared with previous work, successfully obtaining compound 3 with an innovative structure can be attributed to the solvent-induced effect in the process of crystal synthesis, leading to the structure transformation promoting the significantly increased C2H2 adsorption performance. This study provides a platform for improvement of synthetic structures, which can effectively boost gas adsorption performance.

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The isolated three-level DC/DC converter (ITLDC) can be used to charge electric vehicles. During the constant current charging stage, the ITLDC can be designed to realize nature zero voltage switching (ZVS). However, during the constant voltage charging stage, the charging current is small; thus, nature ZVS cannot be realized. This paper presents an active commutation auxiliary circuit (ACAC) for the ITLDC to realize the full load range ZVS. With the proposed ACACs, all the main switches achieve zero-voltage turn-on and quasi zero-voltage turn-off, and the auxiliary switches realize zero current turn-on and zero-voltage turn-off; thus, the efficiency will be high. The auxiliary currents generated by the ACACs are controllable. During the constant current charging stage, the ITLDC realizes nature ZVS and the auxiliary currents are controlled to zero; thus, the ACACs do not result in high current stress or bring in additional losses, and the efficiency will be high. During the constant voltage charging stage, the charging current decreases with charging time and the charging current is too small to realize nature ZVS. Thus, the ITLDC can work with the proposed ACACs and the auxiliary currents can be controlled within a suitable value to realize ZVS. With the proposed ACACs, the ITLDC can realize ZVS during the whole charging process; thus, the efficiency will be high. The structure and operating principle of the ITLDC with ACACs are introduced and the performance of the proposed TLDC is experimentally verified on a 1.5 kW prototype converter.