As the best preserved high-and ultrahigh-pressure (HP and UHP) metamorphic terrane in the QinlingDabieshan-Sulu orogen, western Dabieshan is divided into six lithotectonic units along a traverse across the orogen, i.e. from north to south, the Nanwan, Balifan, Huwan, Xinxian, Hong'an and Mulanshan units. In this terrane five eclogite-bearing zones (I-V) are developed. The garnet and clinopyroxene in eclogites from these zones exhibit chemical zoning, suggesting that the rims record general peak temperature and pressure. Thermobarometric study indicates that the peak P-T conditions of eclogite are 550-570°C and 21 kbar for Zone I, 470-500°C and 14-17 kbar for Zone II, 620-670°C and 26-29 kbar for Zone III, 530-560°C and 20-22 kbar for Zone IV, and 490-510°C and 19-20 kbar for Zone V. The symmetrical thermobaric pattern, in conjunction with structural and geochronological data, demonstrates that the Huwan and Hong'an units belong to the same HP slice overlying the UHP slice. This pattern, together with the Mulanshan LT ⁄ HP blueschist-greenschist belt in the south, roughly constitutes a ÔnormalÕ metamorphic zonation. However, clear metamorphic gaps occur between different slices. It is inferred that the LT ⁄ HP, HP and UHP slices were broken up from the downgoing slab during subduction and reached different depths along different geothermal gradients. The successive subduction of underlying slices leads to a nearly concomitant uplift of overlying slices, whereas exhumation of the deepest UHP slice was effected by underthrusting of the lower crust of the Yangtze craton.

Methanobactins (Mbns) are a family of copper-binding peptides involved in copper uptake by methanotrophs, and are potential therapeutic agents for treating diseases characterized by disordered copper accumulation. Mbns are produced via modification of MbnA precursor peptides at cysteine residues catalyzed by the core biosynthetic machinery containing MbnB, an iron-dependent enzyme, and MbnC. However, mechanistic details underlying the catalysis of the MbnBC holoenzyme remain unclear. Here, we present crystal structures of MbnABC complexes from two distinct species, revealing that the leader peptide of the substrate MbnA binds MbnC for recruitment of the MbnBC holoenzyme, while the core peptide of MbnA resides in the catalytic cavity created by the MbnB–MbnC interaction which harbors a unique tri-iron cluster. Ligation of the substrate sulfhydryl group to the tri-iron center achieves a dioxygen-dependent reaction for oxazolone-thioamide installation. Structural analysis of the MbnABC complexes together with functional investigation of MbnB variants identified a conserved catalytic aspartate residue as a general base required for MbnBC-mediated MbnA modification. Together, our study reveals the similar architecture and function of MbnBC complexes from different species, demonstrating an evolutionarily conserved catalytic mechanism of the MbnBC holoenzymes.

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Mold filling in SCRIMP based on a high‐permeable medium is complicated because of the considerable difference in the permeabilities of the fiber reinforcement, the peel ply and the high permeable medium. The objectives of this paper are to understand the flow mechanism through flow visualization experiments and to present models that can be used to predict the filling time and flow pattern. Permeabilities of a stitched fiber mat, a high‐permeable medium and a peel ply were measured. Flow visualization of SCRIMP mold filling was carried out under various molding conditions. It was found that although the resin flowed faster in the high‐permeable medium than in the fiber reinforcement, the flow front lead‐lag was not very large and it remained nearly constant through the entire mold filling process. A three‐dimensional Control Volume/Finite Element Method (CV/FEM) was adopted to solve the flow governing equations, i.e. the Darcy's law, and the influences of the flow properties of the high‐permeable medium, the fiber reinforcement and the peel ply on filling time were investigated. Based on experimental observations and CV/FEM simulation, a simplified leakage flow model is also presented. The comparison of experimental and simulation results show good agreement.

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This work presents the results of modeling, numerical simulation, and experimental study of resin flow and heat transfer in the resin injection pultrusion (RIP) process. A control volume/finite element method (CV/FEM) was used to solve the flow governing equations, together with heat transfer and chemical reaction models. Resin viscosity, degree of cure, and fiber stack compressibility and permeability were measured in order to understand their influences on the process. An analytical flow model has also been develped based on the one‐dimensional flow approximation for the resin flow in the injection die. A high‐pressure small‐taper injection die was tested with different line speeds. Experimental data were used to verify the simulation results and the analytical solutions.

Efficient conversion of CO2 to commodity chemicals by sustainable way is of great significance for achieving carbon neutrality. Although considerable progress has been made in CO2 utilization, highly efficient CO2 conversion with high space velocity under mild conditions remains a challenge. Here, we report a hierarchical micro/nanostructured silver hollow fiber electrode that reduces CO2 to CO with a faradaic efficiency of 93% and a current density of 1.26 A · cm−2 at a potential of −0.83 V vs. RHE. Exceeding 50% conversions of as high as 31,000 mL · gcat−1 · h−1 CO2 are achieved at ambient temperature and pressure. Electrochemical results and time-resolved operando Raman spectra demonstrate that enhanced three-phase interface reactions and oriented mass transfers synergistically boost CO production.