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Identification and anatomy of oceanic arcs within ancient orogenic belt are significant for better understanding the tectonic framework and closure process of paleo‐ocean basin. This article summarizes the geological, geochemical, and geochronological characteristics of upper crust of Proto‐Tethyan Lajishan intra‐oceanic arc and provides new data to constrain the subduction evolution of the South Qilian Ocean. The intra‐oceanic arc volcanic rocks, including intermediate–mafic lava, breccia, tuff, and minor felsic rocks, are distributed along southern part of the Lajishan ophiolite belt. Geochemical and isotopic compositions indicate that the intermediate–mafic lava were originated from depleted mantle contaminated by sediment melts or hydrous fluids, whereas the felsic rocks were likely generated by partial melting of juvenile mafic crust in intra‐oceanic arc setting. Zircons from felsic rocks yield consistent and concordant ages ranging from 506 to 523 Ma, suggesting these volcanic rocks represent the relicts of upper crust of the Cambrian intra‐oceanic arc. Combined with the Cambrian forearc ophiolite and accretionary complex, we suggest that the Cambrian intra‐oceanic arc in the Lajishan ophiolite belt is belonging to the intra‐oceanic arc system which was generated by south‐directed subduction in the South Qilian Ocean at a relatively short interval between approximately 530 and 480 Ma. [ABSTRACT FROM AUTHOR]

2D covalent organic frameworks with Kagome (kgm) topology are a promising class of crystalline frameworks that possess both triangular and hexagonal pores. These dual‐pore structures enable kgm COFs to exhibit unique advantages in selective separation, mass transfer, and targeted drug release. However, the synthesis of 2D kgm COFs has been hindered by the reliance on empirical methods. This review systematically summarizes the conventional macrocycle‐to‐framework strategy, typical [4+2] co‐polymerization synthetic strategy, and bifunctional molecules self‐condensation approach for constructing 2D kgm COFs. Factors influencing the formation of kgm lattice are surveyed, such as monomer type, solvent polarity, substrate concentration, etc. and highlight the representative examples on targeted synthesis. Additionally, applications of 2D kgm COFs and relationships between structure and performances are summarized. Finally, key fundamental perspectives are proposed to accelerate the further development of this intriguing material. [ABSTRACT FROM AUTHOR]

Targeted synthesis of kagome (kgm) topologic 2D covalent organic frameworks remains challenging, presumably due to the severe dependence on building units and synthetic conditions. Herein, two isomeric "two‐in‐one" monomers with different lengths of substituted arms based on naphthalene core (p‐Naph and m‐Naph) are elaborately designed and utilized for the defined synthesis of isomeric kgm Naph‐COFs. The two isomeric frameworks exhibit splendid crystallinity and showcase the same chemical composition and topologic structure with, however, different pore channels. Interestingly, C60 is able to uniformly be encapsulated into the triangle channels of m‐Naph‐COF via in situ incorporation method, while not the isomeric p‐Naph‐COF, likely due to the different pore structures of the two isomeric COFs. The resulting stable C60@m‐Naph‐COF composite exhibits much higher photoconductivity than the m‐Naph‐COF owing to charge transfer between the conjugated skeletons and C60 guests. [ABSTRACT FROM AUTHOR]

The main protease (Mpro), which is highly conserved and plays a critical role in the replication of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), is a natural biomarker for SARS‐CoV‐2. Accurate assessment of the Mpro activity is crucial for the detection of SARS‐CoV‐2. Herein, we report a nanopore‐based sensing strategy that uses an enzyme‐catalyzed cleavage reaction of a peptide substrate to measure the Mpro activity. The peptide was specifically cleaved by the Mpro, thereby releasing the output products that, when translocated through aerolysin, quantitatively produced the signature current events. The proposed method exhibited high sensitivity, allowing the detection of Mpro concentrations as low as 1 nM without the use of any signal amplification techniques. This simple, convenient, and label‐free nanopore assay may expand the diagnostic tools for viruses. [ABSTRACT FROM AUTHOR]

The development of new linkages is one of the most efficient strategies to enrich the diversity of covalent organic frameworks (COFs). Particularly, functional linkages can endow COFs with additional tailored properties besides the building units, which further diversify COFs with desirable functions. Herein, we have developed a new arylamine linkage for the construction of COFs. Two new arylamine‐linked COFs (AAm‐TPB and AAm‐Py) were prepared by condensing cost‐effective dimethyl succinyl succinate (DMSS) with corresponding multitopic amines (TPB‐NH2 and Py‐NH2). Due to the abundant electroactive diphenylamine moieties in the COF skeletons resembling that of polyaniline (PANI), a state‐of‐the‐art conductive polymer, the pseudocapacitive energy storage performance of AAm‐TPB was further investigated. Remarkably, the AAm‐TPB electrode exhibits a high capacitance of 271 F g−1 with a three‐electrode setup at a discharge rate of 1 A g−1, which represents one of the highest capacitances among the reported COF‐based electrode materials. [ABSTRACT FROM AUTHOR]

We designed and synthesized A2B2 type tetraphenyl benzene monomers (p‐, m‐, and o‐TetPB) which have the para‐, meta, and ortho‐substituted isomeric structures, for the direct construction of isomeric frameworks. Interestingly, both kagome (kgm) and monoclinic square (sql) framework isomers are produced from either p‐TetPB (C2h symmetry) or m‐TetPB (C2v symmetry) by changing reaction solvents, while their isomeric structures are characterized by X‐ray diffraction, computational simulation, microscopy, and sorption isotherm measurements. Only sql frameworks was formed for o‐TetPB (C2v symmetry), irrespective of reaction solvents. These results disclose a unique feature in the framework structural formation, that is, the geometry of monomers directs and dominates the lattice growth process while the solvent plays a role in the perturbation of chain growth pattern. The isomeric frameworks exhibit highly selective adsorption of vitamin B12 owing to pore shape and size differences. [ABSTRACT FROM AUTHOR]

Three isostructural covalent organic frameworks (COFs) with either methoxyl, hydroxyl, or both groups on the channel wall, are synthesized and served as metal‐free heterogeneous catalysts for chemical fixation of CO2. Among them, the COF decorated with both hydroxyl and methoxyl groups named OMe‐OH‐TPBP‐COF exhibits the highest catalytic activity and efficiency for CO2 cycloaddition under mild conditions. [ABSTRACT FROM AUTHOR]

2D conductive metal–organic frameworks (2D c‐MOFs) feature promising applications as chemiresistive sensors, electrode materials, electrocatalysts, and electronic devices. However, exploration of the spin‐polarized transport in this emerging materials and development of the relevant spintronics have not yet been implemented. In this work, layer‐by‐layer assembly was applied to fabricate highly crystalline and oriented thin films of a 2D c‐MOF, Cu3(HHTP)2, (HHTP: 2,3,6,7,10,11‐hexahydroxytriphenylene), with tunable thicknesses on the La0.67Sr0.33MnO3 (LSMO) ferromagnetic electrode. The magnetoresistance (MR) of the LSMO/Cu3(HHTP)2/Co organic spin valves (OSVs) reaches up to 25 % at 10 K. The MR can be retained with good film thickness adaptability varied from 30 to 100 nm and also at high temperatures (up to 200 K). This work demonstrates the first potential applications of 2D c‐MOFs in spintronics. [ABSTRACT FROM AUTHOR]